Recording device and control method thereof, program, and memory medium

Abstract

To provide a recording device capable of shortening time until a recording medium is fed to a recording area opposite to a recording head.SOLUTION: A recording device is equipped with a supply portion that supplies a recording medium, a guide portion that guides the recording medium supplied by the supply portion, a carrying portion that carries the recording medium guided by the guide portion in a carrying direction, a recording portion that records an image to the recording medium carried by the carrying portion on the downstream of the carrying portion, and an inversion path that returns the recording medium recorded by the recording portion and inverting its front and back surfaces to the guide portion. The recording device is equipped with a control portion that can perform control for overlapping a tip end portion of a second recording medium on a rear end portion of a first recording medium in the carrying direction, even if, to the first recording medium being recorded by the recording portion, the second recording medium is supplied to the guide portion from either one of the supply portion or the inversion path.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a recording device capable of automatically reversing a recording medium from a first side to a second side for double-sided printing. [Background technology]

[0002] Patent document 1 discloses a recording device that sequentially controls the leading edge of a subsequent recording medium, which is fed from a paper stacking section after the preceding recording medium that has been inverted by an inversion means, to overlap the leading edge in the transport direction on the preceding recording medium after the preceding recording medium has been inverted by an inversion means after the first side has been printed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-052614 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the device described in Patent Document 1, control is performed to overlap a portion of the succeeding recording medium with the preceding recording medium only when feeding a recording medium from the paper stacking unit, which poses a technical problem in that the succeeding recording medium cannot be continuously overlapped with the preceding recording medium, and it takes time to feed the recording medium to the recording area opposite the recording head.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a recording device that can shorten the time it takes to feed a recording medium to a recording area opposite a recording head. [Means for solving the problem]

[0006] The recording device of the present invention comprises a supply means for supplying a recording medium, a guide section for guiding the recording medium supplied by the supply means, a transport means for transporting the recording medium guided by the guide section in a transport direction, a recording means downstream of the transport means for recording an image on the recording medium transported by the transport means, and an inversion path for returning the recording medium that has been recorded on by the recording means and inverted back to the guide section, and is characterized by comprising a control means that is capable of controlling the leading end of the second recording medium to overlap the trailing end of the first recording medium in the transport direction, regardless of whether the second recording medium is supplied to the guide section from the supply means or the inversion path relative to the first recording medium on which recording is being performed by the recording means. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce the time required to feed the recording medium to the recording area facing the recording head. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view of the main parts of the recording apparatus according to the embodiment of the present invention. [Figure 2] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 3] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 4] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 5] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 6] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 7] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 8] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 9]5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 10] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 11] 5A and 5B are diagrams illustrating overlapping continuous feeding in a recording apparatus according to an embodiment of the present invention. [Figure 12] 10 is a flowchart of an overlapping continuous feeding operation according to an embodiment. [Figure 13] 10 is a flowchart of an overlapping continuous feeding operation according to an embodiment. [Figure 14] 10 is a flowchart of an overlapping continuous feeding operation according to an embodiment. [Figure 15] 10 is a flowchart of an overlapping continuous feeding operation according to an embodiment. [Figure 16] 10 is a flowchart of an overlapping continuous feeding operation according to an embodiment. [Figure 17] 10 is a flowchart of an overlapping continuous feeding operation according to an embodiment. [Figure 18] 10 is a flowchart of an overlapping continuous feeding operation according to an embodiment. [Figure 19] FIG. 1 is a block diagram of a recording apparatus according to an embodiment. [Figure 20] FIG. 2 is a diagram illustrating the configuration of a pickup roller. [Figure 21] 10A and 10B are diagrams illustrating an operation of overlapping a subsequent sheet on a preceding sheet. [Figure 22] 10A and 10B are diagrams illustrating an operation of overlapping a subsequent sheet on a preceding sheet. [Figure 23] 10 is a flowchart illustrating an operation for correcting skew of a subsequent sheet in an embodiment. [Figure 24] 10 is a flowchart illustrating an operation for calculating the leading edge position of a succeeding sheet. [Figure 25] FIG. 2 is a diagram illustrating a recording area on a first surface of a recording medium P according to an embodiment. [Figure 26] 4A and 4B are diagrams illustrating a print determination state for a first surface of a print medium P in an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] 1 is a cross-sectional view illustrating the main components of a recording apparatus 200 according to one embodiment of the present invention. The schematic configuration of the recording apparatus 200 according to this embodiment will be described using the diagrams indicated by STA to STC in FIG.

[0011] In STA in Fig. 1, P is a recording medium. A plurality of recording media P are stacked in paper stacking section 11. Reference numeral 2 denotes a pickup roller that contacts the uppermost recording medium P stacked in paper stacking section 11 and picks up this recording medium. Reference numeral 3 denotes a feed roller that feeds the recording medium P picked up by pickup roller 2 downstream in the conveying direction along first conveying path 100. Reference numeral 4 denotes a feed driven roller that is biased toward feed roller 3 and clamps and feeds recording medium P together with feed roller 3. The portion of first conveying path 100 that guides recording medium P between feed roller 3 and conveying roller 5, which will be described later, is referred to as guide portion 100a.

[0012] A conveying roller 5 conveys the recording medium P fed by the feeding roller 3 and the feeding driven roller 4 to a position facing the recording head 7. A pinch roller 6 is biased toward the conveying roller 5 and pinches and conveys the recording medium P together with the conveying roller 5.

[0013] Reference numeral 7 denotes a recording head that records on the recording medium P transported by the transport roller 5 and pinch roller 6. In this embodiment, the recording head 7 will be described as an inkjet recording head that ejects ink to perform recording on the recording medium P. Reference numeral 8 denotes a platen that supports the second surface (back surface) of the recording medium P at a position opposite the recording head 7. Reference numeral 1 denotes a carriage that carries the recording head 7 and moves in a direction intersecting the recording medium transport direction.

[0014] Reference numeral 9 denotes a reversing roller that rotates (rotates forward) in the direction of arrow A in STA in FIG. 1 by driving a second feeding motor 207 (see FIG. 19) in the forward direction, and is capable of conveying a recording medium P on which recording has been performed by the recording head 7 in the direction of arrow C. The reversing roller 9 can discharge the recording medium P to the outside of the apparatus as shown by arrow C. The portion that guides the discharge of the recording medium P from discharge rollers 10 (described later) to the downstream side of the reversing roller 9 in the conveying direction is referred to as a discharge path 102.

[0015] 1, the recording medium P is conveyed in the direction of arrow C in the STB in FIG. 1, and after the upstream end of the recording medium P in the conveying direction reaches the vicinity of the reversing roller 9, the second feed motor 207 is driven in the reverse direction. As a result, the reversing roller 9 rotates in the direction of arrow B in the STC in FIG. 1 (rotates in the opposite direction), and the recording medium P is turned over and conveyed in the direction of arrow D in the figure along a guide within the second conveying path (reversing path) 101.

[0016] At this time, due to the reverse rotation of the reversing roller 9, the intermediate roller 15 also rotates (reversely) in the direction of arrow B in STC in FIG.

[0017] Reference numeral 10 denotes a discharge roller that conveys the recording medium P on which recording has been performed by the recording head 7 toward the reverse roller 9. Reference numeral 12 denotes a spur that rotates in contact with the recording surface of the recording medium P on which recording has been performed by the recording head 7. Here, the spur 12 is biased toward the discharge roller 10. Reference numeral 13 denotes a reverse driven roller that is biased toward the reverse roller 9 and, together with the reverse roller 9, sandwiches and conveys the recording medium P. Reference numeral 14 denotes an intermediate driven roller that is biased toward the intermediate roller 15 and, together with the intermediate roller 15, sandwiches and conveys the recording medium P.

[0018] Between the feeding nip formed by the feeding roller 3 and the feeding driven roller 4 and the transport nip formed by the transport roller 5 and the pinch roller 6, the recording medium P is guided by a guide within the first transport path 100. Reference numeral 16 denotes a recording medium detection sensor for detecting the leading and trailing ends of the recording medium P. The recording medium detection sensor 16 is provided downstream of the feeding roller 3 in the recording medium transport direction.

[0019] Figure 20 is a diagram illustrating the configuration of the pickup roller 2. As described above, the pickup roller 2 contacts the uppermost recording medium stacked in the paper stacking unit 11 to pick up the recording medium. Reference numeral 19 denotes a drive shaft for transmitting the drive of a first feed motor 206, which will be described later, to the pickup roller 2. When picking up the recording medium P, the drive shaft 19 and pickup roller 2 rotate in the direction of arrow E in STA in Figure 1.

[0020] A protrusion 19a is provided on the drive shaft 19. A recess 2c into which the protrusion 19a fits is formed on the pickup roller 2. As shown in FIG. 20(a), when the protrusion 19a abuts against the first surface 2a of the recess 2c of the pickup roller 2, the drive force of the drive shaft 19 is transmitted to the pickup roller 2, and driving the drive shaft 19 also rotates the pickup roller 2. On the other hand, as shown in FIG. 20(b), when the protrusion 19a abuts against the second surface 2b of the recess 2c of the pickup roller 2, the drive force of the drive shaft 19 is not transmitted to the pickup roller 2, and driving the drive shaft 19 does not rotate the pickup roller 2. When the protrusion 19a is not abutting against either the first surface 2a or the second surface 2b and is between the first surface 2a and the second surface 2b, the pickup roller 2 does not rotate even when the drive shaft 19 is driven.

[0021] 19 is a block diagram of a recording device 200 of this embodiment. 201 is an MPU that controls the operation of each unit and data processing. As will be described later, the MPU 201 also functions as a transport control unit that can control the transport of recording media so that the rear end of a preceding recording medium overlaps the front end of a succeeding recording medium. 202 is a ROM that stores programs and data executed by the MPU 201. 203 is a RAM that temporarily stores processing data executed by the MPU 201 and data received from a host computer 214.

[0022] The print head 7 is controlled by a print head driver 212. A carriage motor 204 that drives the carriage 1 is controlled by a carriage motor driver 208. The transport rollers 5 and discharge rollers 10 are driven by a transport motor 205. The transport motor 205 is controlled by a transport motor driver 209.

[0023] The pickup roller 2, the feed roller 3, and the intermediate roller 15 are driven by a first feed motor 206. The first feed motor 206 is controlled by a first feed motor driver 210. The reversing roller 9 and the intermediate roller 15 are driven by a second feed motor 207.

[0024] At this time, the pickup roller 2 and the feed roller 3 are rotated synchronously by the forward rotation of the first feed motor 206, and the recording medium P is conveyed in the direction of the conveyance roller 5. Furthermore, when the first feed motor 206 is driven in the reverse direction, the following operation is performed by drive switching (not shown). When the first feed motor 206 is driven in the reverse direction in the first drive switching state, only the feed roller 3 rotates and conveys the recording medium P in the direction of the conveyance roller 5. When the first feed motor 206 is driven in the reverse direction in the second drive switching state, the feed roller 3 and the intermediate roller 15 rotate and convey the recording medium P in the direction of the conveyance roller 5.

[0025] When the second feed motor 207 is driven in the forward direction, the reverse roller 9 rotates in the direction to discharge the recording medium P out of the apparatus. When the second feed motor 207 is driven in the reverse direction, the reverse roller 9 and the intermediate roller 15 rotate synchronously, and the recording medium P in the second conveying path 101 is conveyed in the direction of the feed roller 3.

[0026] The host computer 214 is provided with a printer driver 2141 for collecting recording information such as the recorded image and the quality of the recorded image when a user commands the execution of a recording operation, and communicating with the recording device 200. The MPU 201 exchanges recorded images and the like with the host computer 214 via the I / F unit 213.

[0027] 2 to ST29 in Fig. 11, the operation of overlapping continuous feeding in double-sided printing mode will be described in chronological order, taking an example of printing six pages of recording data on both sides of three recording media P in one job. When recording data in double-sided printing mode is sent from the host computer 214 via the I / F unit 213, it is processed by the MPU 201 and then expanded in the RAM 203. The MPU 201 then starts the recording operation based on the expanded data.

[0028] The description will be made with reference to ST1 in FIG. 2. First, the first feed motor 206 is driven forward at a low speed by the first feed motor driver 210. This causes the pickup roller 2 to rotate at 7.6 inches / sec. As the pickup roller 2 rotates, it picks up the topmost recording medium P stacked on the paper stacking unit 11. The first recording medium P picked up by the pickup roller 2 is conveyed by the feed roller 3, which rotates in the same direction as the pickup roller 2, while being guided by the guide unit 100a. The feed roller 3 is also driven by the first feed motor 206. This embodiment will be described with a configuration including the pickup roller 2 and the feed roller 3. However, a configuration may also be made with only the feed roller 3, which feeds the recording media stacked on the paper stacking unit 11.

[0029] When the leading edge of the first recording medium P is detected by the recording medium detection sensor 16 provided downstream of the feed roller 3 in the conveying direction, the first feed motor 206 is switched to high-speed driving while still rotating in the forward direction. That is, the pickup roller 2 and the feed roller 3 rotate at 20 inches / sec.

[0030] This will be explained with reference to ST2 in Figure 2. As the feed roller 3 continues to rotate, the downstream leading edge of the first recording medium P in the transport direction hits the transport nip formed by the transport roller 5 and pinch roller 6. At this time, the transport roller 5 is stopped. By continuing to rotate the feed roller 3 a predetermined amount even after the downstream leading edge of the first recording medium P in the transport direction hits the transport nip, the leading edge of the first recording medium P is aligned with the tip hitting the transport nip, and skew is corrected. The skew correction operation is also called a registration operation.

[0031] This will be explained with reference to ST3 in Figure 2. When the skew correction operation for the first recording medium P is completed, the conveying motor 205 is driven, causing the conveying roller 5 to start rotating. The conveying roller 5 conveys the recording medium at 15 inches / sec. After the first recording medium P is cue-positioned to a position opposite the recording head 7, ink is ejected from the recording head 7 based on the recording data for the first page, and the recording operation for the first side of the first recording medium P begins.

[0032] Here, the length of the recording medium P in the transport direction is set to L as shown in Figure 25. Then, when printing on the first side of the recording medium P, which is to be printed first, the print density of area S at the leading edge ((1 / 4)L portion) in the transport direction at the current stage, indicated by arrow A, is compared with a preset print density. Then, as a result of this comparison, if the print density of area S is within the preset print density range, S(1) = 0 is stored in RAM 203, and if it is not, S(1) = 1 is stored. Note that the number in parentheses indicates the number of sheets to be printed.

[0033] Furthermore, as the printing operation for the first sheet of printing medium P progresses, the print density of region K at the rear end ((1 / 4)L portion) in the conveyance direction at the current stage, indicated by arrow A, is compared with a preset print density. If the comparison shows that the print density of region K is within the preset print density range, K(1)=0 is stored in RAM 203, and if not, K(1)=1 is stored. Similarly, the number in parentheses indicates the number of sheets to be printed.

[0034] Also, as shown in Figure 26, when the number of prints N of the recording medium P becomes 4 or more, the value of N in S(N) and K(N) is converted to the value of M in the table and is overwritten in the memory areas of S(M) and K(M) as needed.

[0035] The cueing operation is performed by first positioning the first recording medium P at the position of the conveying roller 5 when the leading edge of the first recording medium P abuts against the conveying nip portion, and then controlling the amount of rotation of the conveying roller 5 based on the position of the conveying roller 5. During the cueing operation, if the second recording medium P needs to be picked up from the paper stacking unit 11 by the pickup roller 2, the first feed motor 206 is driven in the forward direction, and the pickup roller 2 and the feed roller 3 are also driven in synchronization with the conveying roller 5.

[0036] When there is no need to pick up the second recording medium P, the first feeding motor 206 is driven in the reverse direction in the first drive switching state, and only the feeding roller 3 is driven in synchronization with the conveying roller 5.

[0037] In this embodiment, when there is recording data to be recorded on the second or subsequent recording medium P, the recording medium P to be recorded on after the recording operation on the first side of the first recording medium P is the second recording medium P picked up from the paper stacking unit 11. The second recording medium P is set so that its first side is recorded on after the first side of the first recording medium P. For this reason, it is necessary to pick up the second recording medium P (delay feeding) after the upstream end (rear end) in the transport direction of the first recording medium P passes the pickup roller 2 and the drive shaft 19 has been driven for a predetermined time. For this reason, the first feeding motor 206 is driven in the forward direction.

[0038] The recording device of this embodiment is a serial type recording device in which a recording head 7 is mounted on a carriage 1. A conveying operation in which the recording medium is intermittently conveyed by a predetermined amount by a conveying roller 5, and an image forming operation in which ink is ejected from the recording head 7 while the carriage 1 carrying the recording head 7 is moved while the conveying roller 5 is stopped are repeated. A recording operation on the first sheet of recording medium P is performed by this operation.

[0039] When the first sheet of recording medium P is cue-read, the first feed motor 206 switches from forward rotation to low-speed rotation. That is, the pickup roller 2 and feed roller 3 rotate at 7.6 inches / sec. When the transport roller 5 is intermittently transporting the first sheet of recording medium P by a predetermined amount, the feed roller 3 is also intermittently driven by the first feed motor 206. That is, when the transport roller 5 is rotating, the feed roller 3 also rotates, and when the transport roller 5 is stopped, the feed roller 3 is also stopped. The rotation speed of the feed roller 3 is slower than the rotation speed (transport speed) of the transport roller 5. Therefore, the recording medium P is in a tensioned state between the transport roller 5 and the feed roller 3. That is, the feed roller 3 is rotated together with the first sheet of recording medium P being transported by the transport roller 5.

[0040] Since the first feed motor 206 is intermittently driven in the forward direction, the drive shaft 19 is also driven. As mentioned above, the rotation speed of the pickup roller 2 is slower than that of the transport roller 5. Therefore, the pickup roller 2 is rotated along with the recording medium P transported by the transport roller 5. In other words, the pickup roller 2 is ahead of the drive shaft 19. Specifically, the protrusion 19a of the drive shaft 19 is separated from the first surface 2a and is in contact with the second surface 2b. Therefore, even if the upstream end (rear end) of the first recording medium P in the transport direction passes the pickup roller 2, the second recording medium P is not immediately picked up. When the drive shaft 19 is driven for a predetermined time, the protrusion 19a comes into contact with the first surface 2a, and the pickup roller 2 begins to rotate.

[0041] Due to factors such as sensor responsiveness, the recording medium detection sensor 16 needs a predetermined distance between recording media to detect the edges of the recording media P. That is, after the recording medium detection sensor 16 detects the upstream edge (trailing edge) of the first recording medium P in the transport direction, a predetermined time interval must be allowed before it detects the downstream leading edge of the second recording medium P in the transport direction. To achieve this, the upstream edge of the first recording medium P in the transport direction and the downstream leading edge of the second recording medium P need to be separated by a predetermined distance, and the recess 2c of the pickup roller 2 is set at approximately 70 degrees.

[0042] This will be explained with reference to ST4 in Figure 3. The second recording medium P picked up by the pickup roller 2 is transported by the feed roller 3. At this time, an image is formed on the first recording medium P by the recording head 7 based on the recording data. When the leading edge of the second recording medium P is detected by the recording medium detection sensor 16, the first feed motor 206 is switched to high-speed driving while still rotating in the forward direction. In other words, the pickup roller 2 and the feed roller 3 rotate at 20 inches / sec.

[0043] This will be described with reference to ST5 in Fig. 3. By moving the second recording medium P at a higher speed than the speed at which the first recording medium P moves downstream due to the recording operation by the recording head 7, it is possible to create a state in which the downstream leading edge of the second recording medium P in the transport direction overlaps the upstream edge of the first recording medium P in the transport direction.

[0044] Since the first recording medium P is being recorded on based on the recording data, it is intermittently conveyed by the conveying roller 5. Meanwhile, after the downstream leading edge of the second recording medium P is detected by the recording medium detection sensor 16, the feed roller 3 is continuously rotated at 20 inches / sec, allowing it to catch up with the first recording medium P. The second recording medium P is then conveyed by the feed roller 3 until its downstream leading edge in the conveying direction stops at a predetermined position upstream of the conveying nip. The position of the downstream leading edge of the second recording medium P in the conveying direction is calculated from the amount of rotation of the feed roller 3 after the downstream leading edge of the second recording medium P in the conveying direction is detected by the recording medium detection sensor 16, and is controlled based on this calculation result. At this time, an image is being formed on the first recording medium P by the recording head 7 based on the recording data.

[0045] This will be explained with reference to ST6 in Fig. 3. When the conveying roller 5 is stopped to perform the image forming operation (ink ejection operation) for the last line of the first recording medium P, the feeding roller 3 is driven to abut the leading edge of the second recording medium P against the conveying nip portion, thereby correcting the skew of the second recording medium P.

[0046] This will be explained with reference to ST7 in Fig. 4. When the image forming operation for the last line on the first recording medium P is completed, the conveying roller 5 is rotated a predetermined amount, so that the second recording medium P can be aligned while maintaining the state in which the second recording medium P is superimposed on the first recording medium P.

[0047] After the second recording medium P is fed from the paper stacking unit 11 by the pickup roller 2, it is determined whether the recording medium P to be indexed has been fed from the paper stacking unit 11. If it is determined that the recording medium P to be indexed has been fed from the paper stacking unit 11, the recording medium P next to this recording medium P is selected to be supplied from the second conveyance path 101 to a position facing the recording head 7. Since it is determined in this determination that the second recording medium P has been fed from the paper stacking unit 11, the recording medium P next to the second recording medium P to be indexed is supplied from the second conveyance path 101 to a position facing the recording head 7. It is also necessary to prevent the recording medium P next to the second recording medium P to be indexed from the paper stacking unit 11 with a delayed feed. Since the second recording medium P has been fed from the paper stacking unit 11, the indexing of the second recording medium P is performed by driving the first feed motor 206 in the reverse direction in the first drive switching state. Then, the drive force is not transmitted to the pickup roller 2 and the intermediate roller 15, and the feed roller 3 is controlled to be driven together with the conveying roller 5.

[0048] When the second sheet of recording medium P is cue-fed, the first feed motor 206 is switched to low-speed drive while remaining in the reverse drive state in the first drive switching state. That is, the feed roller 3 rotates at 7.6 inches / sec. While the conveying roller 5 is intermittently conveying the second sheet of recording medium P by a predetermined amount at a time, the feed roller 3 is also intermittently driven by the first feed motor 206. A printing operation is performed on the second sheet of recording medium P by the print head 7 based on the print data.

[0049] At this time, the print densities are compared in the same way as when printing on the first side of the first recording medium P described above, and if the print density of area S is within the preset print density range, S(2) = 0 is stored in RAM 203; if it is not, S(2) = 1 is stored. Also, as the recording operation on the second recording medium P progresses, the print density of area K at the trailing end ((1 / 4)L portion) in the transport direction of the second recording medium at the current stage is compared with the preset print density (see FIG. 25). Then, as a result of this comparison, if the print density of area K is within the preset print density range, K(2) = 0 is stored in RAM 203; if it is not within the preset print density range, K(2) = 1 is stored. When the second recording medium P is transported intermittently for the recording operation, the first recording medium P is also transported intermittently.

[0050] This will be explained with reference to ST8 in FIG. 4. After determining that the upstream end of the first recording medium P in the transport direction has passed the spur 12 based on the amount of rotation of the transport roller 5 since the start of the cueing operation and the length of the paper, the second feed motor driver 211 drives the second feed motor 207 forward at high speed. The reversing roller 9 rotates in the direction of arrow A in FIG. 1 at 18 inches / sec. This causes the speed at which the first recording medium P is transported by the reversing roller 9 to be faster than the speed at which the second recording medium P is transported by the transport roller 5. This eliminates the overlap between the upstream end of the first recording medium P in the transport direction and the downstream leading edge of the second recording medium P in the transport direction. Thereafter, as will be described later, the first recording medium P is reversed by the reversing roller 9 and enters the second transport path 101. After its upstream trailing edge in the transport direction passes the reversing roller 9, the downstream leading edge of the second recording medium P in the transport direction can pass the reversing roller 9. The upstream rear end of the first recording medium P in the second conveying path 101 means the downstream front end in the first conveying path 100 before being reversed.

[0051] This will be explained with reference to ST9 in Fig. 4. When the reversing roller 9 rotates in the direction of arrow A in STA in Fig. 1, the first recording medium P is transported in the direction of arrow C in STA in Fig. 1. As a result, the first recording medium P is continuously transported until its upstream end in the transport direction reaches a predetermined position upstream of the reversing roller 9 in the transport direction. As a result, the upstream end in the transport direction of the first recording medium P and the downstream leading edge in the transport direction of the second recording medium P, which is being intermittently transported by a predetermined amount, are separated.

[0052] This will be explained with reference to ST10 in Figure 5. When the upstream end of the first sheet of recording medium P in the transport direction reaches a predetermined position upstream of the reversing roller 9 in the transport direction, the second feed motor driver 211 switches the second feed motor 207 to high-speed reverse rotation. This causes the reversing roller 9 and intermediate roller 15 to rotate at 18 inches / sec in the direction of arrow B in STC in Figure 1. The first sheet of recording medium P is then transported by the reversing roller 9 and intermediate roller 15 along a guide within the second transport path (reversing path) 101 until its downstream leading edge in the transport direction reaches a predetermined position in front of the first transport path 100. The predetermined position at this time is also calculated from the amount of rotation of the transport roller 5 from the start of the cueing operation and the length of the paper.

[0053] This will be explained with reference to ST11 in FIG. 5. As the second recording medium P continues to be conveyed, when the recording medium detection sensor 16 detects the upstream edge of the second recording medium P in the conveying direction, the first feed motor driver 210 drives the first feed motor 206 in the second drive switching state at low speed in the reverse direction. This causes the intermediate roller 15 and the feed roller 3 to rotate at 7.6 inches / sec in the direction of arrow B in STC in FIG. 1. The first recording medium P is then conveyed by the intermediate roller 15 and the feed roller 3 from the second conveying path 101 through the first conveying path 100 toward the conveying roller 5. At this time, an image is being formed on the second recording medium P by the recording head 7 based on the recording data. When the recording medium detection sensor 16 detects the downstream edge of the first recording medium P in the conveying direction, the first feed motor 206 is switched to high speed driving while still in the second drive switching state in the reverse direction. In other words, the intermediate roller 15 and the feed roller 3 rotate at 20 inches / sec.

[0054] Before switching the first feeding motor 206 to high-speed driving, the values ​​in the RAM 203 described above for the downstream end of the first recording medium P in the conveying direction and the upstream end of the second recording medium P in the conveying direction are checked. Note that the downstream end of the first recording medium P in the second conveying path 101 refers to the upstream end in the first conveying path 100 before it is turned over. That is, the values ​​of K(1) stored in the RAM 203 when recording on the rear end of the first side of the first recording medium P and K(2) in the K area of ​​the second recording medium P are checked. If both K(1) and K(2) are 0, the first feeding motor 206 is switched to high-speed driving. If either K(1) or K(2) is 1, the preceding and succeeding recording media may not be able to be stacked due to curling of the recording media P, so the first feeding motor 206 is not switched to high-speed driving.

[0055] At this stage, the value of K(2) in the K region of the second recording medium P is the initial value of 0 because image data has not yet been recorded. Therefore, when the value of K(1) is 1, the first feeding motor 206 is not switched to high-speed driving, and the leading edge of the first recording medium P on the downstream side in the conveying direction is not overlapped with the upstream edge of the second recording medium P in the conveying direction. We will now continue to explain the case where the value of K(1) is 0 and the first feeding motor 206 is switched to high-speed driving.

[0056] By moving the first recording medium P at a high speed relative to the speed at which the second recording medium P moves downstream due to the recording operation by the recording head 7, it is possible to create a state in which the leading edge of the first recording medium P overlaps the trailing edge of the second recording medium P. Since the recording operation for the second recording medium P is performed based on the recording data, the second recording medium P is intermittently conveyed by the conveying roller 5. Meanwhile, after the leading edge of the first recording medium P is detected by the recording medium detection sensor 16, it is possible for the first recording medium P to catch up with the second recording medium P by continuously rotating the feed roller 3 and intermediate roller 15 at 20 inches / sec.

[0057] Thereafter, the first recording medium P is conveyed by the feed roller 3 until its downstream leading edge in the conveyance direction stops at a predetermined position upstream of the conveyance nip. The position of the downstream leading edge of the first recording medium P in the conveyance direction is calculated from the amount of rotation of the feed roller 3 after the downstream leading edge of the first recording medium P in the conveyance direction is detected by the recording medium detection sensor 16, and is controlled based on this calculation result. At this time, an image formation operation is being performed on the second recording medium P by the recording head 7 based on the recording data.

[0058] This will be explained with reference to ST12 in Fig. 5. When the conveying roller 5 is stopped to perform the image forming operation (ink ejection operation) of the last line of the second recording medium P, the feed roller 3 is driven to abut the downstream leading edge of the first recording medium P in the conveying direction against the conveying nip portion, thereby correcting the skew of the first recording medium P.

[0059] This will be described with reference to ST13 in Fig. 6. When the image forming operation for the last line on the second recording medium P is completed, the conveying roller 5 is rotated a predetermined amount, so that the first recording medium P can be positioned on top of the second recording medium P.

[0060] As described above, it is determined whether the recording medium P to be indexed has been fed from the paper stacking unit 11 after the second recording medium P has been fed from the paper stacking unit 11 by the pickup roller 2. If it is determined from this determination that the recording medium P has been fed from the second conveyance path 101, it is further determined whether the data to be recorded on the second side of the recording medium P on which the recording operation was performed immediately before the indexing is the last recording data in one job. If it is determined that the recording medium P to be indexed has been fed from the second conveyance path 101 and the data to be recorded on the second side of the recording medium P on which the recording operation was performed immediately before the indexing is the last recording data in one job, the control is performed as follows. That is, the recording medium P next to the recording medium P to be indexed is selected so as to be supplied from the second conveyance path to a position facing the recording head 7.

[0061] Furthermore, when the recording medium P to be cue-read is fed from the second conveyance path 101 and it is determined that the data to be recorded on the second side of the recording medium P on which the immediately preceding recording operation is being performed is not the last data to be recorded in one job, the control is performed as follows: That is, the recording medium P next to the recording medium P to be cue-read is selected so as to be supplied from the paper stacking unit 11 to a position facing the recording head 7.

[0062] In this determination, it is determined that the first recording medium P has been fed from the second conveying path 101, and that the recording data on the second side of the second recording medium P is not the final recording data in one job. Therefore, the recording medium P next to the first recording medium P to be cue-aligned is supplied from the paper stacking unit 11 to a position facing the recording head 7. It is also necessary to prevent the recording medium P next to the first recording medium P to be cue-aligned from the paper stacking unit 11 with a delay. Furthermore, the first recording medium P has been fed from the second conveying path 101. Therefore, to cue-align the first recording medium P, the first feed motor 206 is driven in the reverse direction in the second drive switching state, and the drive is not transmitted to the pickup roller 2, so that the feed roller 3 and intermediate roller 15 are driven together with the conveying roller 5.

[0063] The intermediate roller 15 and the intermediate driven roller 14 are positioned so that when the first recording medium P is cue-aligned, the upstream end of the first recording medium P in the conveying direction passes through the nip of the intermediate roller 15.

[0064] Next, the first feed motor 206 starts to be driven at a low speed in the forward direction in the first drive switching state. That is, the pickup roller 2 and the intermediate roller 3 rotate at 7.6 inches / sec. While the transport roller 5 is intermittently transporting the first recording medium P by a predetermined amount at a time, the pickup roller 2 and the feed roller 3 are also intermittently driven by the first feed motor 206. A recording operation is performed on the first recording medium P by the recording head 7 based on the recording data. When the first recording medium P is transported intermittently for the recording operation, the third recording medium P picked up by the pickup roller 2 from the paper stacking unit 11 is also transported intermittently.

[0065] This will be explained with reference to ST14 in FIG. 6. After determining that the upstream end of the second recording medium P in the transport direction has passed the spur 12 based on the amount of rotation of the transport roller 5 since the start of the cueing operation and the length of the paper, the second feed motor driver 211 drives the second feed motor 207 forward at high speed. The reversing roller 9 rotates in the direction of arrow A in FIG. 1 at 18 inches / sec. This causes the speed at which the second recording medium P is transported by the reversing roller 9 to be faster than the speed at which the first recording medium P is transported by the transport roller 5. This eliminates the overlap between the upstream end of the second recording medium P in the transport direction and the downstream leading edge of the first recording medium P in the transport direction. The second recording medium P is then reversed by the reversing roller 9 and enters the second transport path 101. After its upstream trailing edge passes the reversing roller 9, the downstream leading edge of the first recording medium P in the transport direction can pass the reversing roller 9. The upstream rear end of the second recording medium P in the second conveying path 101 means the downstream front end in the first conveying path 100 before being reversed.

[0066] This will be explained with reference to ST15 in Fig. 6. When the reversing roller 9 rotates in the direction of arrow A in STA in Fig. 1, the second recording medium P is transported in the direction of arrow C in STA in Fig. 1. As a result, the second recording medium P is continuously transported until its upstream end in the transport direction reaches a predetermined position upstream of the reversing roller 9 in the transport direction. As a result, the upstream end in the transport direction of the second recording medium P and the downstream leading edge in the transport direction of the first recording medium P, which is being intermittently transported by a predetermined amount, are separated.

[0067] When the upstream edge of the second recording medium P in the transport direction reaches a predetermined position upstream of the reversing roller 9 in the transport direction, the second feeding motor driver 211 switches the second feeding motor 207 to high-speed reverse rotation. This causes the reversing roller 9 and intermediate roller 15 to rotate at 18 inches / sec in the direction of arrow B in the STC in FIG. 1. The second recording medium P is then transported by the reversing roller 9 and intermediate roller 15 along a guide within the second transport path (reversing path) 101 until its downstream leading edge reaches a predetermined position just before the first transport path 100. The predetermined position at this time is also calculated from the amount of rotation of the transport roller 5 from the start of the cueing operation and the length of the paper.

[0068] The following description will be given with reference to ST16 in Figure 7. The third sheet of recording medium P, picked up by pickup roller 2 from paper stacker 11, is transported by feed roller 3. At this time, an image is being formed on the first sheet of recording medium P by recording head 7 based on recording data. When recording medium detection sensor 16 detects the leading edge of the third sheet of recording medium P, first feed motor 206 is switched to high-speed driving while still rotating in the forward direction. In other words, pickup roller 2 and feed roller 3 rotate at 20 inches / sec.

[0069] In this case, as in the operation described above, before switching the first feeding motor 206 to high-speed driving, the values ​​in the RAM 203 described above are checked for the upstream end of the preceding recording medium P in the conveyance direction and the downstream leading edge of the succeeding recording medium P in the conveyance direction. That is, the values ​​of S(1) stored in the RAM 203 when recording on the leading edge of the first side of the first recording medium P and S(3) of the S area of ​​the third recording medium P are checked. Note that the S area of ​​the leading edge of the first recording medium P when recording on the first side is turned over and supplied to the recording position via the second conveyance path 101 becomes the upstream end (rear edge) in the conveyance direction of the first recording medium P. If both S(1) and S(3) are 0, the first feeding motor 206 is switched to high-speed driving. If either S(1) or S(3) is 1, the preceding and succeeding recording media may not be able to be stacked due to curling of the recording medium P, so the first feeding motor 206 is not switched to high-speed driving. At this stage, the value of S(3) in the S area of ​​the third recording medium P is the initial value of 0 because image data has not yet been recorded. If the value of S(1) is 1, the first feeding motor 206 is not switched to high-speed driving, and the leading edge of the third recording medium P on the downstream side in the conveying direction is not overlapped with the upstream edge of the first recording medium P in the conveying direction. We will now continue to explain the case where the value of S(1) is 0 and the first feeding motor 206 is switched to high-speed driving.

[0070] This will be described with reference to ST17 in FIG. 7. By moving the third recording medium P at a higher speed than the speed at which the first recording medium P moves downstream due to the recording operation of the recording head 7, it is possible to create a state in which the leading edge of the third recording medium P overlaps the trailing edge of the first recording medium P. Since the first recording medium P is being recorded based on the recording data, the first recording medium P is intermittently conveyed by the conveyance roller 5. Meanwhile, after the leading edge of the third recording medium P is detected by the recording medium detection sensor 16, the feed roller 3 is continuously rotated at 20 inches / sec, allowing it to catch up with the first recording medium P. Thereafter, the third recording medium P is conveyed by the feed roller 3 until its leading edge on the downstream side in the conveyance direction stops at a predetermined position upstream of the conveyance nip. The position of the leading edge of the third recording medium P on the downstream side in the conveyance direction is calculated from the amount of rotation of the feed roller 3 after the leading edge of the third recording medium P on the downstream side in the conveyance direction is detected by the recording medium detection sensor 16, and is controlled based on this calculation result. At this time, the first recording medium P is undergoing an image forming operation by the recording head 7 based on the recording data.

[0071] This will be described with reference to ST18 in Fig. 7. When the conveying roller 5 is stopped to perform the image forming operation (ink ejection operation) for the last line of the first recording medium P, the feeding roller 3 is driven to abut the leading edge of the third recording medium P against the conveying nip portion, thereby performing a skew correction operation for the third recording medium P.

[0072] This will be described with reference to ST19 in Fig. 8. When the image forming operation for the last line on the first recording medium P is completed, the conveying roller 5 is rotated a predetermined amount, so that the third recording medium P can be cue-aligned while maintaining the state in which the third recording medium P is superimposed on the first recording medium P.

[0073] As described above, it is determined whether the recording medium P to be indexed has been fed from the paper stacking unit 11 after the second recording medium P has been fed from the paper stacking unit 11 by the pickup roller 2. If this determination determines that the recording medium P has been fed from the paper stacking unit 11, the recording medium P after this recording medium P to be indexed is selected to be supplied from the second conveying path 101 to a position facing the recording head 7. In this determination, it is determined that the third recording medium P has been fed from the paper stacking unit 11, so the recording medium P after the third recording medium P to be indexed is supplied from the second conveying path 101 to a position facing the recording head 7. It is also necessary to prevent the recording medium P after the third recording medium P to be indexed from being fed with a delay from the paper stacking unit 11. The third recording medium P has also been fed from the paper stacking unit 11. Therefore, when the third recording medium P is to be cue-aligned, the first feed motor 206 is driven in reverse in the first drive switching state, and the driving force is not transmitted to the pickup roller 2 and the intermediate roller 15, and the feed roller 3 is controlled to be driven together with the conveying roller 5.

[0074] When the third recording medium P is cue-fed, the first feed motor 206 is switched to low-speed drive while still in the reverse drive state in the first drive switching state. That is, the feed roller 3 rotates at 7.6 inches / sec. While the transport roller 5 intermittently transports the third recording medium P by a predetermined amount, the first feed motor 206 also intermittently drives the feed roller 3. The print head 7 performs a printing operation on the third recording medium P based on the print data. At this time, the print density is compared in the same way as when printing on the first side of the second recording medium P described above. If the print density of the S region is within the preset print density range, S(3) = 0 is stored in RAM 203. If it is not within the preset print density range, S(3) = 1 is stored. Furthermore, as the printing operation on the third recording medium P progresses, the print density of the K region at the current trailing end ((1 / 4)L portion) in the transport direction of the third recording medium is compared with the preset print density. If the comparison result shows that the print density of the K region is within a preset print density range, K(3) = 0 is stored in RAM 203, and if not, K(3) = 1 is stored. When the third recording medium P is intermittently transported for the recording operation, the first recording medium P is also intermittently transported.

[0075] This will be explained with reference to ST20 in Figure 8. After it is determined from the amount of rotation of the transport roller 5 since the start of the cueing operation and the length of the paper that the upstream end of the first recording medium P in the transport direction has passed the spur 12, the second feed motor driver 211 drives the second feed motor 207 in the forward direction at high speed. The reversing roller 9 rotates in the direction of arrow A in Figure 1 at 18 inches / sec. As a result, the speed at which the reversing roller 9 transports the first recording medium P is faster than the speed at which the transport roller 5 transports the third recording medium P. As a result, the upstream end of the first recording medium P in the transport direction and the downstream front end of the third recording medium P no longer overlap.

[0076] The following description will be given with reference to ST21 in Figure 8. When the reversing roller 9 rotates in the direction of arrow A in STA in Figure 1, the first recording medium P is transported in the direction of arrow C in STA in Figure 1. Recording has been completed on the first and second sides of the first recording medium P. Therefore, the rotation of the reversing roller 9 in the direction of arrow A in STA in Figure 1 at 18 inches / sec causes the first recording medium P to be ejected outside the device. In addition, the upstream end of the first recording medium P in the transport direction is separated from the downstream leading edge of the third recording medium P, which is being intermittently transported by a predetermined amount.

[0077] This will be described with reference to ST22 and ST23 in FIG. 9. As the third recording medium P continues to be conveyed, its upstream edge in the conveying direction reaches the position where the intermediate roller 15 starts to convey the second recording medium P from the second conveying path 101. Then, the first feed motor driver 210 drives the first feed motor 206 in the second drive switching state at low speed in the reverse direction. This causes the intermediate roller 15 and the feed roller 3 to rotate at 7.6 inches / sec in the direction of arrow B in STC in FIG. 1. The second recording medium P is then conveyed by the intermediate roller 15 and the feed roller 3 from the second conveying path 101 through the first conveying path 100 toward the conveying roller 5. At this time, an image is being formed on the third recording medium P by the recording head 7 based on the recording data. When the recording medium detection sensor 16 detects the downstream leading edge of the second recording medium P in the conveying direction, the first feed motor 206 switches to high-speed driving while still in the second drive switching state in the reverse direction. That is, the intermediate roller 15 and the feed roller 3 rotate at 20 inches / sec.

[0078] In this case, as in the operation described above, before switching the first feeding motor 206 to high-speed driving, the values ​​stored in the RAM 203 for the upstream end of the preceding recording medium P in the conveyance direction and the downstream leading edge of the succeeding recording medium P in the conveyance direction are checked. That is, the value of K(3) in the K area of ​​the upstream end of the third recording medium P and the value of K(2) for the downstream leading edge stored in the RAM 203 when recording on the trailing edge of the first side of the second recording medium P are checked. Note that the downstream leading edge of the second recording medium P in the second conveyance path 101 refers to the upstream trailing edge of the first conveyance path 100 before it is inverted. If both K(3) and K(2) are 0, the first feeding motor 206 is switched to high-speed driving. If either K(3) or K(2) is 1, the preceding and succeeding recording media may not be able to be stacked due to curling of the recording media P, so the first feeding motor 206 is not switched to high-speed driving. At this stage, the value of K(3) in the K region of the third recording medium P is the initial value of 0 because image data has not yet been recorded. Therefore, when the value of K(2) is 1, the first feeding motor 206 is not switched to high-speed driving, and the leading edge of the second recording medium P on the downstream side in the conveying direction is not overlapped with the upstream edge of the third recording medium P in the conveying direction. We will now continue to explain the case where the value of K(2) is 0 and the first feeding motor 206 is switched to high-speed driving.

[0079] By moving the second recording medium P at a high speed relative to the speed at which the third recording medium P moves downstream due to the recording operation of the recording head 7, it is possible to create a state in which the leading edge of the second recording medium P overlaps the trailing edge of the third recording medium P. Since the third recording medium P is being recorded based on the recording data, the third recording medium P is intermittently conveyed by the conveyance roller 5. Meanwhile, after the leading edge of the second recording medium P is detected by the recording medium detection sensor 16, the feed roller 3 and intermediate roller 15 are continuously rotated at 20 inches / second, allowing it to catch up with the third recording medium P. Thereafter, the second recording medium P is conveyed by the feed roller 3 until its leading edge on the downstream side in the conveyance direction stops at a predetermined position upstream of the conveyance nip. The leading edge position of the second recording medium P is calculated from the amount of rotation of the feed roller 3 after the leading edge of the second recording medium P is detected by the recording medium detection sensor 16, and is controlled based on this calculation result. At this time, an image is being formed on the third recording medium P by the recording head 7 based on the recording data.

[0080] This will be described with reference to ST24 in Fig. 9. When the conveying roller 5 is stopped to perform the image forming operation (ink ejection operation) for the final line of the third recording medium P, the feed roller 3 is driven to abut the downstream leading edge of the second recording medium P in the conveying direction against the conveying nip portion, and a skew correction operation for the second recording medium P is performed.

[0081] This will be described with reference to ST25 in Fig. 10. When the image forming operation for the last line of the third recording medium P is completed, the conveying roller 5 is rotated a predetermined amount, so that the second recording medium P can be aligned while maintaining the state in which the second recording medium P is superimposed on the third recording medium P.

[0082] As described above, it is determined whether the recording medium P to be indexed has been fed from the paper stacking unit 11 after the second recording medium P has been fed from the paper stacking unit 11 by the pickup roller 2. If it is determined from this determination that the recording medium P has been fed from the second conveyance path 101, it is further determined whether the data to be recorded on the second side of the recording medium P on which the immediately preceding recording operation has been performed is the last data to be recorded in one job. If it is determined that the recording medium P to be indexed has been fed from the second conveyance path 101 and the data to be recorded on the second side of the recording medium P on which the immediately preceding recording operation has been performed is the last data to be recorded in one job, the following control is performed. That is, the recording medium P next to the recording medium P to be indexed is selected so as to be supplied from the second conveyance path to a position facing the recording head 7. Furthermore, if it is determined from the above determination that the recording medium P to be indexed has been fed from the second conveyance path 101 and the data to be recorded on the second side of the recording medium P on which the immediately preceding recording operation has been performed is not the last data to be recorded in one job, the following control is performed. That is, the recording medium P next to the recording medium P to be cue-aligned is selected so as to be supplied from the paper stacking unit 11 to a position facing the recording head 7.

[0083] In this determination, the second recording medium P is fed from the second conveying path 101, and it is determined that the recording data to be printed on the second side of the third recording medium P is the last recording data in one job. Therefore, the recording medium P following the second recording medium P to be cue-aligned is supplied from the second conveying path 101 to a position facing the recording head 7. It is also necessary to prevent the recording medium P following the second recording medium P to be cue-aligned from the paper stacking unit 11 with a delay. The second recording medium P has been fed from the second conveying path 101. Therefore, to cue-align the second recording medium P, the first feed motor 206 is driven in the reverse direction in the second drive switching state, and the drive is not transmitted to the pickup roller 2, but the feed roller 3 and intermediate roller 15 are controlled to be driven together with the conveying roller 5.

[0084] When the second recording medium P is cue-fed, the first feed motor 206 is switched to low-speed drive while remaining in the reverse drive state in the second drive switching state. That is, the feed roller 3 and the intermediate roller rotate at 7.6 inches / sec. The second recording medium P is intermittently transported by the transport roller 5 at predetermined intervals. A printing operation is performed on the second recording medium P by the print head 7 based on the print data. When the second recording medium P is intermittently transported for the printing operation, the third recording medium P is also intermittently transported.

[0085] This will be explained with reference to ST26 in FIG. 10. After determining that the upstream end of the third recording medium P in the transport direction has passed the spur 12 based on the amount of rotation of the transport roller 5 since the start of the cueing operation and the length of the paper, the second feed motor driver 211 drives the second feed motor 207 forward at high speed. The reversing roller 9 rotates in the direction of arrow A in FIG. 1 at 18 inches / sec. This causes the speed at which the third recording medium P is transported by the reversing roller 9 to be faster than the speed at which the second recording medium P is transported by the transport roller 5. This eliminates the overlap between the upstream end of the third recording medium P in the transport direction and the downstream leading edge of the second recording medium P in the transport direction. The third recording medium P is then reversed by the reversing roller 9 and enters the second transport path 101. After its upstream trailing edge passes the reversing roller 9, the downstream leading edge of the second recording medium P in the transport direction can pass the reversing roller 9. The upstream rear end of the third recording medium P in the second conveying path 101 means the downstream front end in the first conveying path 100 before being reversed.

[0086] When the reversing roller 9 rotates in the direction of arrow A in STA in Fig. 1, the third recording medium P is transported in the direction of arrow C in STA in Fig. 1. As a result, the third recording medium P is continuously transported until its upstream end in the transport direction reaches a predetermined position upstream of the reversing roller 9. As a result, the upstream end in the transport direction of the third recording medium P is separated from the downstream leading edge in the transport direction of the second recording medium P, which is being intermittently transported by a predetermined amount at a time.

[0087] This will be explained with reference to ST27 in Figure 10. When the upstream end of the third recording medium P in the transport direction reaches a predetermined position upstream of the reversing roller 9 in the transport direction, the second feeding motor driver 211 switches the second feeding motor 207 to high-speed reverse rotation. This causes the reversing roller 9 and intermediate roller 15 to rotate at 18 inches / sec in the direction of arrow B in STC in Figure 1. The third recording medium P is then transported by the reversing roller 9 and intermediate roller 15 along a guide within the second transport path (reversing path) 101 until its downstream leading edge in the transport direction reaches a predetermined position just before the first transport path 100. The predetermined position at this time is also calculated from the amount of rotation of the transport roller 5 from the start of the cueing operation and the length of the paper.

[0088] This will be explained with reference to ST28 in FIG. 11. As the second recording medium P continues to be conveyed, its upstream edge in the conveying direction reaches a position where the intermediate roller 15 starts to convey the third recording medium P from the second conveying path 101 (described later). Then, the first feed motor driver 210 drives the first feed motor 206 in the second drive switching state at low speed in the reverse direction. This rotates the intermediate roller 15 and the feed roller 3 in the direction of arrow B in FIG. 1 at 7.6 inches / sec. The third recording medium P is then conveyed by the intermediate roller 15 and the feed roller 3 from the second conveying path 101 through the first conveying path 100 toward the conveying roller 5. At this time, an image is being formed on the second recording medium P by the recording head 7 based on the recording data. When the recording medium detection sensor 16 detects the downstream leading edge of the third recording medium P in the conveying direction, the first feed motor 206 switches to high-speed drive while still being driven in the reverse direction in the second drive switching state. That is, the intermediate roller 15 and the feed roller 3 rotate at 20 inches / sec.

[0089] In this case, as in the situation described above, before switching the first feeding motor 206 to high-speed drive, the values ​​stored in the RAM 203 for the upstream end of the preceding recording medium P in the conveying direction and the downstream leading edge of the succeeding recording medium P in the conveying direction are checked. That is, the value of S(2) stored in the RAM 203 when recording on the leading edge of the first side of the second recording medium P and the value of K(3) stored in the RAM 203 when recording on the trailing edge of the first side of the third recording medium P are checked. Note that the downstream leading edge of the third recording medium P in the second conveying path 101 refers to the upstream end (trailing edge) on the first conveying path 100 before it is inverted. If both S(2) and K(3) are 0, the first feeding motor 206 is switched to high-speed drive. If either S(2) or K(3) is 1, it is possible that the preceding and succeeding recording media cannot be stacked due to curling of the recording media P. Therefore, the first feeding motor 206 is not switched to high-speed drive. The following will continue to explain the case where the values ​​of S(2) and K(3) are 0 and the first feed motor 206 is switched to high-speed driving.

[0090] By moving the third recording medium P at a high speed relative to the speed at which the second recording medium P moves downstream due to the recording operation of the recording head 7, it is possible to create a state in which the leading edge of the third recording medium P overlaps the trailing edge of the second recording medium P. Since the second recording medium P is being recorded based on the recording data, the second recording medium P is intermittently conveyed by the conveyance roller 5. Meanwhile, after the leading edge of the third recording medium P is detected by the recording medium detection sensor 16, the feed roller 3 and intermediate roller 15 are continuously rotated at 20 inches / second, allowing it to catch up with the second recording medium P. The third recording medium P is then conveyed by the feed roller 3 until its leading edge on the downstream side in the conveyance direction stops at a predetermined position upstream of the conveyance nip. The position of the leading edge on the downstream side in the conveyance direction of the third recording medium P is calculated from the amount of rotation of the feed roller 3 after the leading edge on the downstream side in the conveyance direction of the third recording medium P is detected by the recording medium detection sensor 16, and is controlled based on this calculation result. At this time, the recording head 7 is performing an image formation operation on the second recording medium P based on the recording data.

[0091] The following will be explained with reference to ST29 in Figure 11. When the transport roller 5 is stopped to perform the image formation operation (ink ejection operation) of the last line of the second recording medium P, the feed roller 3 is driven to abut the downstream leading edge of the third recording medium P in the transport direction against the transport nip portion, thereby performing a skewed straightening operation of the third recording medium P. When the image formation operation of the last line of the second recording medium P is completed, the transport roller 5 is rotated a predetermined amount, so that the third recording medium P can be positioned on top of the second recording medium P.

[0092] When the skew correction operation for the third recording medium P is completed, the conveying motor 205 is driven, and the conveying roller 5 starts to rotate. The conveying roller 5 conveys the recording medium at 15 inches / sec. After the third recording medium P is cue-positioned to a position facing the recording head 7, the recording data for the sixth page is recorded by ejecting ink from the recording head 7 based on the recording data.

[0093] Based on the rotation amount of the transport roller 5 from the start of the cueing operation and the length of the paper, it is determined that the upstream edge of the second recording medium P in the transport direction has passed the spur 12. After this, the second feed motor driver 211 drives the second feed motor 207 forward at high speed. The reversing roller 9 rotates in the direction of arrow A in STA in FIG. 1 at 18 inches / sec. As a result, the speed at which the reversing roller 9 transports the second recording medium P is faster than the speed at which the transport roller 5 transports the third recording medium P. As a result, the upstream edge of the second recording medium P in the transport direction and the downstream leading edge of the third recording medium P no longer overlap. Because recording on the first and second sides of the second recording medium P has been completed, the reversing roller 9 rotates in the direction of arrow A in STA in FIG. 1 at 18 inches / sec, causing the second recording medium P to be ejected from the device.

[0094] When the image formation operation for the last line on the third recording medium P is completed, recording on the first and second sides of the third recording medium P, which is the last recording medium in one job, is completed. Therefore, the reversing roller 9 is rotated at 18 inches / sec in the direction of arrow A in STA in Figure 1. In addition, the discharge roller 10 and the transport roller 5 are also rotated at 18 inches / sec in the same direction as the reversing roller 9, thereby discharging the third recording medium P out of the device and completing double-sided printing.

[0095] 12 to 18 are flowcharts of the overlapping continuous feeding operation in the double-sided printing mode of this embodiment. The following describes the case where six pages of recording data are recorded on the first side of three recording media P, which is the first side to be recorded on, and the second side, which is the reverse side of the first side.

[0096] In step S1 of FIG. 12, when recording data in the double-sided printing mode is sent from the host computer 214 via the I / F unit 213, the recording operation in the double-sided printing mode is started.

[0097] In step S2, N=1 is stored in RAM 203 as an initial value for managing how many sheets of recording medium P have been fed from paper stacking unit 11 in one job. In step S3, F=0 is stored in RAM 203 as an initial value for managing whether recording has been performed on the first or second side of recording medium P. F=0 indicates recording on the first side, and F=1 indicates recording on the second side. In step S4, P=0 is stored in RAM 203 as an initial value for managing whether the feeding operation of recording medium P to a position opposite recording head 7 has started from paper stacking unit 11 or second conveyance path 101. P=0 indicates feeding from paper stacking unit 11, and P=1 indicates feeding from second conveyance path 101.

[0098] If it is determined in step S5 that the number of recording media P fed from the paper stacking unit 11 in one job is the first, the process proceeds to the "Feeding 1 from Paper Stacking Unit" subroutine shown in step S30 of FIG.

[0099] In step S31, the feeding operation of the first recording medium P is started from the paper stacking unit 11. Specifically, the feeding motor 206 is driven forward at a low speed. The pickup roller 2 rotates at 7.6 inches / sec. As a result, the pickup roller 2 picks up the first recording medium P, and the feeding roller 3 feeds it toward the recording head 7.

[0100] In step S32, P=0 is stored in RAM 203 to record that recording medium P has been fed from paper stacking unit 11. When recording medium detection sensor 16 detects the downstream leading edge of the first recording medium P in the transport direction in step S33, feeding motor 206 is switched to high-speed driving in step S34. That is, pickup roller 2 and feeding roller 3 rotate at 20 inches / sec. After recording medium detection sensor 16 detects the downstream leading edge of the first recording medium P in the transport direction, the amount of rotation of feeding roller 3 is controlled. As a result, in step S35, the downstream leading edge of the first recording medium P in the transport direction is abutted against the transport nip portion, and skew correction of the first recording medium P is performed.

[0101] In step S36, the first sheet of recording medium P is cue-aligned based on the recording data. That is, by controlling the amount of rotation of the transport roller 5, the first sheet of recording medium P is transported to a recording start position based on the position of the transport roller 5 based on the recording data. In step S37, the feed motor 206 is switched to low-speed drive. This causes the pickup roller 2 and feed roller 3 to rotate at 7.6 inches / sec. In step S38, the "Feed 1 from Paper Stacker" subroutine is completed, and the process proceeds to step S8 in FIG. 12, where it proceeds to the "Printing Operation" subroutine.

[0102] The "printing operation" subroutine will be described with reference to Figure 15. If it is determined in step S15 that the number of recording media P fed from the paper stacking unit 11 in one job is one, then in step S16 the recording operation is started by ejecting ink from the recording head 7 onto the first side of the first recording medium P based on the recording data for the first page. Specifically, a transport operation in which the transport roller 5 transports the first recording medium P intermittently and an image forming operation (ink ejection operation) in which the carriage 1 is moved and ink is ejected from the recording head 7 are repeated. In this way, the recording operation on the first side of the first recording medium P is performed.

[0103] The first feeding motor 206 is driven intermittently at a low speed in synchronization with the operation of intermittently conveying the first recording medium P by the conveying roller 5. That is, the pickup roller 2 and the feeding roller 3 rotate intermittently at 7.6 inches / sec.

[0104] Here, the length of the recording medium P in the transport direction is set to L as shown in Figure 25. Then, the print density of area S at the leading edge ((1 / 4)L portion) in the transport direction at the current stage, indicated by arrow A, of the first recording medium P is compared with a preset print density. Then, as a result of this comparison, if the print density of area S is within the preset print density range, S(1) = 0 is stored in RAM 203, and if it is not, S(1) = 1 is stored. Note that the number in parentheses indicates the number of sheets to be printed.

[0105] Furthermore, as the printing operation for the first sheet of printing medium P progresses, the print density of region K at the rear end ((1 / 4)L portion) of the first sheet of printing medium in the current conveyance direction, indicated by arrow A, is compared with a preset print density. If the comparison shows that the print density of region K is within the preset print density range, K(1)=0 is stored in RAM 203, and if it is not, K(1)=1 is stored. Similarly, the number in parentheses indicates the number of sheets to be printed.

[0106] Also, as shown in Figure 26, if the number of prints N on the recording medium P is 4 or more, the N value in S(N) and K(N) is converted to the M value in the table and is overwritten in the memory areas of S(M) and K(M) as needed.

[0107] In step S17, it is determined whether there is recording data for page 2. If it is determined that there is no recording data for page 2, the process proceeds to step S130 to go to the "discharge operation 2" subroutine in FIG.

[0108] In step S131, if it is determined from the amount of rotation of the conveyance roller 5 since the start of the cueing operation and the length of the paper that the upstream end of the first recording medium P in the conveyance direction has passed the spur 12, in step S132 the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec. Then, in step S133 the first recording medium P is discharged outside the apparatus, and in step S134 the "discharge operation 2" subroutine ends. Thereafter, in step S176 of FIG. 15, double-sided printing ends.

[0109] If it is determined in step S17 that there is recording data for the second page, F=0 is stored in RAM 203 in step S18 to record that the recording operation has been performed on the first side of the recording medium P, and in step S40 the process proceeds to the "Feed 2 from paper stacker" subroutine in Figure 13.

[0110] In step S41, the upstream end of the first recording medium P in the transport direction passes the pickup roller 2, and after the drive shaft 19 has been driven for a predetermined time, the second recording medium P is picked up. Specifically, the second recording medium P is picked up (delay fed) by the pickup roller 2 from the paper stacking unit 11 at 7.6 inches / sec. In step S42, P=0 is stored in RAM 203 to record that the second recording medium P has been fed from the paper stacking unit 11.

[0111] When the downstream leading edge of the second recording medium P in the transport direction is detected by the recording medium detection sensor 16 in step S43, the feed motor 206 is switched to high-speed driving in step S44. That is, the pickup roller 2 and the feed roller 3 rotate at 20 inches / sec. The amount of rotation of the feed roller 3 after the downstream leading edge of the second recording medium P in the transport direction is detected by the recording medium detection sensor 16 is controlled. As a result, the downstream leading edge of the second recording medium P in the transport direction stops 10 mm before the transport nip in step S45. Then, in step S46, in order to record that the second recording medium P has been fed from the paper stacking unit 11 within one job, 1 is added to N in the RAM 203, and N=2 is stored. In step S47, the "Feed 2 from Paper Stacking Unit" subroutine is terminated, and the process proceeds to step S19 in FIG. 15.

[0112] In step S19, it is determined whether a predetermined condition is met for overlapping the downstream leading edge of the succeeding recording medium P in the transport direction with the upstream edge of the preceding recording medium P in the transport direction. The predetermined condition will be described later. If it is determined in step S19 that the predetermined condition is not met, the process proceeds to step S210, where it moves to a "cancel overlapping state" subroutine.

[0113] The "overlap state release" subroutine will be described with reference to Figure 18. In step S211, the value of F in RAM 203 is checked, and if it is determined that F = 0, that is, that printing on the first side of recording medium P is being performed, in step S212 it is determined whether the value of P stored in RAM 203 is 0. In this case, since 0 was stored in step S42, the process proceeds to step S213. If it is determined in step S213 that the image formation operation for the last line on the first sheet of recording medium P has been completed, in step S214 the first sheet of recording medium P is conveyed at 18 inches / sec by the conveyance rollers 5 and discharge rollers 10.

[0114] In step S215, if it is determined that the upstream edge of the first recording medium P in the conveying direction has passed the spur 12 based on the amount of rotation of the conveying roller 5 since the start of the cueing operation and the length of the paper, then in step S216, the drive of the conveying motor 205 is stopped. Because the feed motor 206 is not driven until the drive of the conveying motor 205 is stopped, the downstream edge of the second recording medium P in the conveying direction remains stopped at a position 10 mm before the conveying nip portion. This eliminates the overlapping state of the first recording medium P and the second recording medium P. Furthermore, in step S217, the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec, so that the first recording medium P continues to be conveyed until the upstream edge of the first recording medium P in the conveying direction reaches a position 5 mm upstream of the nip portion of the reversing roller 9 in the conveying direction.

[0115] In step S218, the feed roller 3 is driven at 15 inches / sec, causing the leading edge of the second recording medium P to abut against the conveyance nip portion and performing a skew correction operation on the second recording medium P, and in step S219, the second recording medium P is cue-aligned based on the recording data. That is, by controlling the rotation amount of the conveyance roller 5, the second recording medium P is conveyed to the recording start position based on the position of the conveyance roller 5 based on the recording data. Then, in step S220, the feed motor 206 is switched to low-speed driving, and the feed roller 3 is rotated at 7.6 inches / sec.

[0116] In step S221, the reversing roller 9 and the intermediate roller 15 are continuously driven in the reverse direction at 18 inches / sec. As a result, the first recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 along the guide in the second conveying path 101. Then, in step S222, the first recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 until its downstream leading edge in the conveying direction reaches a position 5 mm before the first conveying path 100, where it stops. Thereafter, the process returns to step S22 in FIG. 15, and the processes from step S22 onwards are performed on the second recording medium P.

[0117] If it is determined in step S19 that the predetermined conditions are met, the value of F in RAM 203 is checked in step S20, and if it is determined that F=0, that is, that the recording on recording medium P is the first side, it is determined in step S21 whether the value of P stored in RAM 203 is 0. In this case, since 0 was stored in step S42, the process proceeds to the "Printing Operation 1" subroutine in step S70.

[0118] The "Printing Operation 1" subroutine will be described with reference to FIG. 16. In step S71, it is determined whether the operation for forming the final line of an image on the first recording medium P has begun. If the image formation operation has begun, in step S72, the downstream leading edge of the second recording medium P in the conveying direction is abutted against the conveying nip portion while maintaining the overlapping state, thereby correcting the skew of the second recording medium P. Then, in step S73, if it is determined that the operation for forming the final line of an image on the first recording medium P has ended, in step S74, the second recording medium P is aligned based on the recording data while maintaining the overlapping state with the first recording medium P. That is, by controlling the rotation amount of the conveying roller 5, the second recording medium P is conveyed to the recording start position based on the position of the conveying roller 5 based on the recording data. In step S75, the feed motor 206 is switched to low-speed driving, and in step S76, the "Printing Operation 1" subroutine is terminated, and the process returns to step S22 in the printing operation sequence of FIG. 15.

[0119] In step S22, the recording operation on the first side of the second recording medium P is started by ejecting ink from the recording head 7 based on the recording data for the third page onto the first side of the second recording medium P. Specifically, the recording operation on the first side of the second recording medium P is performed by repeating a transport operation in which the transport roller 5 intermittently transports the second recording medium P, and an image forming operation (ink ejection operation) in which the carriage 1 is moved and ink is ejected from the recording head 7. Then, in step S23, F=0 is stored in RAM 203 to record that the recording operation on the first side of the recording medium P has been performed, and the "printing operation" subroutine is ended in step S25.

[0120] As already explained, the length of the recording medium P in the transport direction is set to L as shown in Figure 25. When printing on the first side of the recording medium P, which is to be printed first, the print density of area S at the leading edge ((1 / 4)L portion) in the transport direction at the current stage, indicated by arrow A in Figure 25, is compared with a preset print density. If the comparison shows that the print density of area S is within the preset print density range, S(2) = 0 is stored in RAM 203, and if it is not, S(2) = 1 is stored. Note that the number in parentheses indicates the number of sheets to be printed.

[0121] Furthermore, as the printing operation for the second printing medium P progresses, the print density of the K region at the rear end ((1 / 4)L portion) in the conveying direction at the current stage, indicated by arrow A, is compared with the preset print density. If the comparison shows that the print density of the K region is within the preset print density range, K(2)=0 is stored in RAM 203, and if not, K(2)=1 is stored.

[0122] Also, as shown in Figure 26, if the number N of recording media P is 4 or more, the N value of S(N) and K(N) is converted to the M value in the table and is overwritten in the memory areas of S(M) and K(M) as needed.

[0123] Returning to the overall sequence of Fig. 12, in step S210, it is determined whether F stored in RAM 203 is 0. Since F = 0 at the current stage, it is determined in step S211 whether N stored in RAM 203 is 2. Since N = 2 at the current stage, the process proceeds to step S101.

[0124] In step S101, it is determined whether the recording operation on the recording medium P is the first side. Since the value of F in RAM 203 is currently 0, it is determined that the recording operation on the recording medium P is the first side, and the process proceeds to step S102. If it is determined in step S102 that the upstream end of the first recording medium P in the transport direction has passed the spur 12, the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec in step S103. The forward drive is continuously performed until the upstream end of the first recording medium P in the transport direction reaches a position 5 mm upstream of the nip portion of the reversing roller 9 in the transport direction.

[0125] In step S104, the reversing roller 9 and the intermediate roller 15 are continuously driven in the reverse direction at 18 inches / sec. As a result, the first recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 along the guide in the second conveying path 101. Then, in step S105, the first recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 until its downstream leading edge in the conveying direction reaches a position 5 mm before the first conveying path 100, where it stops, and the process proceeds to step S5.

[0126] If it is determined in step S5 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (currently N=2), it is determined in step S6 whether F in RAM 203 is 1. Since F=0 at the current stage, the process proceeds to step S60 to proceed to the "Feed 1 from the second transport path" subroutine.

[0127] The "Feeding 1 from the Second Conveying Path" subroutine will be described with reference to FIG. 14. In step S61, it is determined whether it is time for the intermediate roller 15 to start feeding the first recording medium P from the second conveying path 101. When the recording medium P being recorded on by the recording head 7 is fed from the paper stacking unit 11 and the subsequent recording medium P is fed from the second conveying path 101, the timing for starting feeding by the intermediate roller 15 is as follows. Based on the amount of rotation of the conveying roller 5 from the start of the cueing operation and the length of the paper, the feeding start timing is when the distance between the upstream end of the second recording medium P in the conveying direction and the downstream front end of the first recording medium P waiting in the second conveying path 101 reaches a positional relationship of 10 mm. Based on this relationship, the drive of the intermediate roller 15 is started so that feeding of the first recording medium P from the second conveying path 101 by the intermediate roller 15 begins.

[0128] In step S62, the feeding operation of the first recording medium P is started from the second conveying path 101. Specifically, the first feeding motor 206 is driven in the second drive switching state in the reverse direction at a low speed. This causes the intermediate roller 15 and the feeding roller 3 to rotate at 7.6 inches / sec. Then, the first recording medium P is fed toward the recording head 7 by the intermediate roller 15 and the feeding roller 3.

[0129] In step S63, P=1 is stored in RAM 203 to record that recording medium P has been fed from second conveying path 101. When recording medium detection sensor 16 detects the downstream leading edge of first recording medium P in the conveying direction in step S64, it is determined in step S65 whether K(2)=0 and K(1)=0 in RAM 203. Here, first recording medium P, which is the subsequent recording medium, is reversed by reversing roller 9 and conveyed on second conveying path 101. Therefore, the downstream leading edge of first recording medium, which is the subsequent recording medium and overlaps the rear edge of second recording medium P, which is the preceding recording medium, is the upstream rear edge of first conveying path 100 (area K in FIG. 25). Therefore, in step S65, it is determined whether K(2)=0 and K(1)=0 in RAM 203.

[0130] If either one is determined to be 1, the first feed motor 206 is not switched to high-speed driving because there is a possibility that the preceding and succeeding recording media cannot be stacked due to curling of the recording media P.

[0131] Therefore, the intermediate roller 15 and the feed roller 3 are driven synchronously with the conveying roller 5 at 7.6 inches / sec, and the process proceeds to step S67. Then, in step S67, the amount of rotation of the feed roller 3 after the downstream leading edge of the first recording medium P in the conveying direction is detected by the recording medium detection sensor 16 is controlled. As a result, when the downstream leading edge of the first recording medium P in the conveying direction reaches a position 10 mm before the conveying nip portion, the conveyance of the first recording medium P is stopped. Then, in the next step S68, the "Feed 1 from the second conveying path" subroutine is ended.

[0132] If it is determined in step S65 that K(2)=0 and K(1)=0 in RAM 203, then in step S66 the first feed motor 206 is switched to high-speed driving. That is, the intermediate roller 15 and the feed roller 3 rotate at 20 inches / sec. The amount of rotation of the intermediate roller 15 and the feed roller 3 after the downstream leading edge of the first recording medium P in the conveying direction is detected by the recording medium detection sensor 16 is controlled. As a result, in step S67 the downstream leading edge of the first recording medium P in the conveying direction stops 10 mm before the conveying nip. Then, in step S68 the "Feed 1 from the second conveying path" subroutine is completed, and the process returns to the overall sequence of FIG. 12, and in step S8 the process proceeds to the "Printing operation" subroutine.

[0133] The "printing operation" subroutine will be described with reference to Figure 15. If it is determined in step S15 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (currently N=2), it is determined in step S19 whether a predetermined condition, which will be described later, is met. If it is determined in step S19 that the predetermined condition is not met, the process proceeds to step S210, where it moves to the "overlap state release" subroutine.

[0134] The "overlap state release" subroutine will be described with reference to Figure 18. In step S211, the value of F in RAM 203 is checked, and if it is determined that F = 0, that is, that printing on the first side of recording medium P is being performed, in step S212 it is determined whether the value of P stored in RAM 203 is 0. In this case, since 1 was stored in step S63, the process proceeds to step S224. If it is determined in step S224 that the image formation operation for the last line on the second recording medium P has been completed, in step S225 the second recording medium P is conveyed at 18 inches / sec by the conveyance rollers 5 and discharge rollers 10.

[0135] In step S226, if it is determined that the upstream edge of the second recording medium P in the conveying direction has passed the spur 12 based on the amount of rotation of the conveying roller 5 since the start of the cueing operation and the length of the paper, then in step S227, the drive of the conveying motor 205 is stopped. Because the feed motor 206 is not driven until the drive of the conveying motor 205 is stopped, the downstream edge of the first recording medium P in the conveying direction remains stopped at a position 10 mm before the conveying nip portion. This eliminates the overlapping state between the second recording medium P and the first recording medium P. Furthermore, in step S228, the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec, so that the second recording medium P continues to be conveyed until the upstream edge of the second recording medium P in the conveying direction reaches a position 5 mm upstream of the nip portion of the reversing roller 9 in the conveying direction.

[0136] In step S229, the feed roller 3 is driven at 15 inches / sec, causing the leading edge of the first recording medium P to abut against the conveyance nip portion, and skew correction of the first recording medium P is performed, and in step S230, the first recording medium P is cue-aligned based on the recording data. That is, by controlling the rotation amount of the conveyance roller 5, the first recording medium P is conveyed to the recording start position based on the position of the conveyance roller 5 based on the recording data. Then, in step S231, the feed motor 206 is switched to low-speed driving, and the feed roller 3 is rotated at 7.6 inches / sec.

[0137] In step S232, the reversing roller 9 and the intermediate roller 15 are continuously driven in the reverse direction at 18 inches / sec. As a result, the second recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 along the guide in the second conveying path 101. Then, in step S233, the second recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 until its downstream leading edge in the conveying direction reaches a position 5 mm before the first conveying path 100, where it stops. Thereafter, the process returns to step S170 in FIG. 15, and the processes from step S170 onwards are performed on the first recording medium P.

[0138] If it is determined in step S19 that the predetermined conditions are met, the value of F in RAM 203 is checked in step S20, and if it is determined that F=0, that is, that the recording on recording medium P is the first side, it is determined in step S21 whether the value of P stored in RAM 203 is 0. Since 1 is currently stored, the process proceeds to step S80 to proceed to the "Printing Operation 2" subroutine.

[0139] The "Printing Operation 2" subroutine will be described with reference to FIG. 16. In step S81, it is determined whether the operation of forming the final line of an image on the second recording medium P has started. If the image forming operation has started, in step S82, the downstream leading edge of the first recording medium P in the conveying direction is abutted against the conveying nip portion while maintaining the overlapping state, thereby correcting the skew of the first recording medium P. Then, in step S83, if it is determined that the operation of forming the final line of an image on the second recording medium P has finished, in step S84, the first recording medium P is aligned based on the recording data while maintaining the overlapping state with the second recording medium P. That is, by controlling the rotation amount of the conveying roller 5, the first recording medium P is conveyed to the recording start position based on the position of the conveying roller 5 based on the recording data. In step S85, the feed motor 206 is switched to low-speed driving, and in step S86, the "Printing Operation 2" subroutine is terminated, and the process returns to step S170 in the "Printing Operation" subroutine of FIG. 15.

[0140] In step S170, the recording operation is started by ejecting ink from the recording head 7 based on the recording data for the second page onto the second side of the first recording medium P. Specifically, the recording operation on the second side of the first recording medium P is performed by repeating a transport operation in which the transport roller 5 intermittently transports the first recording medium P, and an image forming operation (ink ejection operation) in which the carriage 1 is moved and ink is ejected from the recording head 7. Then, in step S24, F=1 is stored in RAM 203 to record that the recording operation on the second side of the recording medium P has been performed, and the "printing operation" subroutine is ended in step S25.

[0141] Returning to the overall sequence of Fig. 12, in step S210 it is determined whether F stored in RAM 203 is 0. Since F = 1 at the current stage, when it is determined in step S181 that the upstream end of the second recording medium P in the transport direction has passed the spur 12, in step S182 the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec. The forward drive is continued until the upstream end of the second recording medium P in the transport direction reaches a position 5 mm upstream of the nip portion of the reversing roller 9 in the transport direction.

[0142] In step S183, the reversing roller 9 and the intermediate roller 15 are continuously driven in the reverse direction at 18 inches / sec. As a result, the second recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 along the guide in the second conveying path 101. Then, in step S184, the second recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 until its downstream leading edge in the conveying direction reaches a position 5 mm before the first conveying path 100, where it stops, and the process proceeds to step S5.

[0143] If it is determined in step S5 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (N=2 at the current stage), it is determined in step S6 whether F in RAM 203 is 1. Since F=1 at the current stage, it is determined in step S7 whether there is recording data for the fifth page onwards, and if there is recording data, the process proceeds to step S50 to proceed to the "Feeding from Paper Stacking Unit 3" subroutine.

[0144] The "Feeding 3 from Paper Stacker" subroutine will be described with reference to FIG. 13. In step S51, it is determined whether the timing has come for the pickup roller 2 to start feeding the third recording medium P from the paper stacker 11. When the recording medium P being recorded on by the recording head 7 is fed from the second conveyance path 101 and the subsequent recording medium P is fed from the paper stacker 11, the timing for the pickup roller 2 to start feeding is as follows. It is assumed that the first recording medium P being recorded on by the recording head 7 is being conveyed within the first conveyance path 100. The feeding start timing occurs when the distance between the upstream end of the first recording medium P in the conveyance direction and the downstream front end of the third recording medium P waiting in the paper stacker 11 in the conveyance direction, estimated from the amount of rotation of the conveyance roller 5 since the start of the cueing operation and the length of the paper, is 10 mm. Based on this relationship, the pickup roller 2 is started to drive so that the pickup roller 2 starts feeding the third recording medium P from the paper stacker 11. When it is determined in step S51 that the timing for starting feeding has been reached, in step S52 the pickup roller 2 starts feeding the third recording medium P from the paper stacking unit 11 at 7.6 inches / sec. In step S53, P=0 is stored in RAM 203 to record that the recording medium P fed toward the recording head 7 has been fed from the paper stacking unit 11.

[0145] When the recording medium detection sensor 16 detects the downstream leading edge of the third recording medium P in the conveying direction in step S54, it is determined in step S55 whether S(1)=0 and S(3)=0 in RAM 203. Here, the first recording medium P, which is the preceding recording medium, is reversed by the reversing roller 9 and conveyed on the second conveying path 101. Therefore, the rear end of the first recording medium P, which is the preceding recording medium and on which the leading edge of the third recording medium, which is the succeeding recording medium, overlaps, is the downstream leading edge in the first conveying path 100 (area S in FIG. 25). Therefore, in step S55, it is determined whether S(1)=0 and S(3)=0 in RAM 203.

[0146] If either of these is determined to be 1, the first feed motor 206 is not switched to high-speed driving because curling of the recording medium P may prevent the preceding and succeeding recording media from overlapping. Therefore, the pickup roller 2 and feed roller 3 are driven synchronously with the conveyance roller 5 at 7.6 inches / sec, and the process proceeds to step S57. Then, in step S57, the amount of rotation of the feed roller 3 after the downstream leading edge of the third recording medium P in the conveyance direction is detected by the recording medium detection sensor 16 is controlled. As a result, when the downstream leading edge of the third recording medium P in the conveyance direction reaches a position 10 mm before the conveyance nip, the conveyance of the third recording medium P is stopped. Then, in the next step S58, 1 is added to the value of N in RAM 203, making N=3, and the "Feed 3 from Paper Stacker" subroutine is terminated in step S59.

[0147] If it is determined in step S55 that S(1)=0 and S(3)=0 in the RAM 203, the first feed motor 206 is switched to high-speed driving in step S56. That is, the pickup roller 2 and the feed roller 3 rotate at 20 inches / sec. Then, the amount of rotation of the feed roller 3 is controlled after the downstream leading edge of the third recording medium P in the transport direction is detected by the recording medium detection sensor 16. As a result, in step S57, the third recording medium P is transported so that the downstream leading edge of the third recording medium P in the transport direction is positioned 10 mm before the transport nip portion. The first recording medium P is transported intermittently based on the print data. By continuously driving the first feed motor 206 at high speed, an overlapping state is formed in which the downstream leading edge of the third recording medium P in the transport direction overlaps the upstream edge of the first recording medium P in the transport direction. In step S58, 1 is added to the value of N in RAM 203 to set N=3, and in step S59, the "Feed 3 from Paper Stacker" subroutine is terminated. Then, the process returns to the overall sequence of Fig. 12, and in step S8, the "Printing Operation" subroutine is started.

[0148] The "printing operation" subroutine will be described with reference to Figure 15. If it is determined in step S15 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (currently N=3), it is determined in step S19 whether a predetermined condition, which will be described later, is met. If it is determined in step S19 that the predetermined condition is not met, the process proceeds to step S210, where it moves to the stacking state release subroutine.

[0149] The "overlap state release" subroutine will be described with reference to Figure 18. In step S211, the value of F in RAM 203 is checked, and if it is determined that F = 1, that is, that printing on the second side of recording medium P is being performed, then in step S234 it is determined whether the value of P stored in RAM 203 is 0. Since 0 is currently stored, the process proceeds to step S235. If it is determined in step S235 that the image formation operation for the last line on the first sheet of recording medium P has been completed, then in step S236 the first sheet of recording medium P is conveyed at 18 inches / sec by the conveyance rollers 5 and discharge rollers 10.

[0150] In step S237, if it is determined from the amount of rotation of the conveyance roller 5 since the start of the cueing operation and the length of the paper that the upstream end of the first recording medium P in the conveyance direction has passed the spur 12, the drive of the conveyance motor 205 is stopped in step S238. Since the feed motor 206 is not driven until the drive of the conveyance motor 205 is stopped, the downstream leading edge of the third recording medium P in the conveyance direction remains stopped at a position 10 mm before the conveyance nip. This eliminates the overlapping state of the first recording medium P and the third recording medium P. Furthermore, in step S239, the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec, and the first recording medium P is ejected out of the apparatus in step S240.

[0151] In step S241, the feed roller 3 is driven at 15 inches / sec, causing the leading edge of the third recording medium P to abut against the conveyance nip portion, and skew correction of the third recording medium P is performed. In step S242, the third recording medium P is cue-aligned based on the recording data. That is, by controlling the rotation amount of the conveyance roller 5, the third recording medium P is conveyed to the recording start position based on the position of the conveyance roller 5 based on the recording data. Then, in step S243, the feed motor 206 is switched to low-speed driving, and the feed roller 3 is rotated at 7.6 inches / sec. Thereafter, the process returns to step S22 in FIG. 15, and the processes from step S22 onwards are performed on the third recording medium P.

[0152] If it is determined in step S19 that the predetermined conditions are met, the value of F in RAM 203 is checked in step S20, and if it is determined that F=1, that is, that recording on recording medium P is the second side, it is determined in step S172 whether the value of P stored in RAM 203 is 0. Since 0 is currently stored, the process proceeds to step S90 to proceed to the "Printing Operation 3" subroutine.

[0153] The "Printing Operation 3" subroutine will be described with reference to FIG. 16. In step S91, it is determined whether the operation of forming the final line of an image on the first recording medium P has begun. If the image formation operation has begun, in step S92, the downstream leading edge of the third recording medium P in the conveying direction is abutted against the conveying nip portion while maintaining the overlapping state, thereby performing a skew correction operation on the third recording medium P. Then, in step S93, if it is determined that the operation of forming the final line of an image on the first recording medium P has ended, in step S94, the third recording medium P is aligned based on the recording data while maintaining the overlapping state with the third recording medium P. That is, by controlling the rotation amount of the conveying roller 5, the third recording medium P is conveyed to the recording start position based on the position of the conveying roller 5 based on the recording data. In step S95, the feed motor 206 is switched to low-speed driving, and in step S96, the "Printing Operation 3" subroutine is terminated, and the process returns to step S22 in the "Printing Operation" subroutine of FIG. 15.

[0154] In step S22, the recording operation is started by ejecting ink from the recording head 7 onto the first side of the third recording medium P based on the recording data for the fifth page. Specifically, the recording operation on the first side of the third recording medium P is performed by repeating a transport operation in which the transport roller 5 intermittently transports the third recording medium P, and an image forming operation (ink ejection operation) in which the carriage 1 is moved and ink is ejected from the recording head 7. Then, in step S23, F=0 is stored in RAM 203 to record that the recording operation on the first side of the recording medium P has been performed, and the "printing operation" subroutine is ended in step S25.

[0155] As already explained, the length of the recording medium P in the transport direction is set to L as shown in Figure 25. When printing on the first side of the recording medium P, which is to be printed first, the print density of area S at the leading edge ((1 / 4)L portion) in the transport direction at the current stage, indicated by arrow A in Figure 25, is compared with a preset print density. If the comparison shows that the print density of area S is within the preset print density range, S(3) = 0 is stored in RAM 203, and if it is not, S(3) = 1 is stored. Note that the number in parentheses indicates the number of sheets to be printed.

[0156] Furthermore, as the printing operation for the third sheet of printing medium P progresses, the print density of the K region at the rear end ((1 / 4)L portion) in the conveying direction at the current stage, indicated by arrow A, is compared with the preset print density. If the comparison shows that the print density of the K region is within the preset print density range, K(3)=0 is stored in RAM 203, and if not, K(3)=1 is stored.

[0157] Also, as shown in Figure 26, if the number N of recording media P is 4 or more, the N value of S(N) and K(N) is converted to the M value in the table and is overwritten in the memory areas of S(M) and K(M) as needed.

[0158] Returning to the overall sequence of FIG. 12, in step S210 it is determined whether F stored in RAM 203 is 0. Since F=0 at the current stage, in step S211 it is determined whether N stored in RAM 203 is 2. Since it is 3 at the current stage, in step S201 it is determined whether the upstream end of the first recording medium P in the conveying direction has passed through spurs 12 based on the amount of rotation of conveying roller 5 since the start of the cueing operation and the length of the paper. If it is determined that it has passed through, in step S202 the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec. Then, in step S203 the first recording medium P is ejected outside the apparatus, and the process proceeds to step S5.

[0159] If it is determined in step S5 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (currently N=3), it is determined in step S6 whether F in RAM 203 is 1. Since F=0 at the current stage, the process proceeds to step S60 to proceed to the "Feed 1 from the second transport path" subroutine.

[0160] The "Feeding 1 from the Second Conveying Path" subroutine will be described with reference to FIG. 14. In step S61, it is determined whether it is time for the intermediate roller 15 to start feeding the second recording medium P from the second conveying path 101. When the recording medium P being recorded on by the recording head 7 is fed from the paper stacking unit 11 and the subsequent recording medium P is fed from the second conveying path 101, the timing for starting feeding by the intermediate roller 15 is as follows. Based on the amount of rotation of the conveying roller 5 from the start of the cueing operation and the length of the paper, the feeding start timing is when the distance between the upstream end of the third recording medium P in the conveying direction and the downstream front end of the second recording medium P waiting in the second conveying path 101 reaches a positional relationship of 10 mm. Based on this relationship, the drive of the intermediate roller 15 is started so that feeding of the second recording medium P from the second conveying path 101 by the intermediate roller 15 begins.

[0161] In step S62, the feeding operation of the second recording medium P is started from the second conveying path 101. Specifically, the first feeding motor 206 is driven in the second drive switching state in the reverse direction at a low speed. This causes the intermediate roller 15 and the feeding roller 3 to rotate at 7.6 inches / sec. Then, the second recording medium P is fed toward the recording head 7 by the intermediate roller 15 and the feeding roller 3.

[0162] In step S63, P=1 is stored in RAM 203 to record that recording medium P has been fed from second conveying path 101. When recording medium detection sensor 16 detects the downstream leading edge of second recording medium P in the conveying direction in step S64, it is determined in step S65 whether K(3)=0 and K(2)=0 in RAM 203. Here, second recording medium P, which is the subsequent recording medium, is reversed by reversing roller 9 and conveyed on second conveying path 101. Therefore, the downstream leading edge of second recording medium, which is the subsequent recording medium and overlaps the rear edge of third recording medium P, which is the preceding recording medium, is the upstream rear edge of first conveying path 100 (area K in FIG. 25). Therefore, in step S65, it is determined whether K(3)=0 and K(2)=0 in RAM 203.

[0163] If either one of them is determined to be 1, there is a possibility that the preceding and succeeding recording media cannot be stacked due to curling of the recording media P, so the first feeding motor 206 is not switched to high-speed driving. Therefore, the intermediate roller 15 and feeding roller 3 are driven synchronously with the conveying roller 5 at 7.6 inches / sec, and the process proceeds to step S67.

[0164] Then, in step S67, the amount of rotation of the feed roller 3 after the downstream leading edge in the transport direction of the second recording medium P is detected by the recording medium detection sensor 16 is controlled. As a result, when the downstream leading edge in the transport direction of the second recording medium P reaches a position 10 mm before the transport nip portion, the transport of the second recording medium P is stopped. Then, in the next step S68, the "Feed 1 from the second transport path" subroutine is ended.

[0165] If it is determined in step S65 that K(3)=0 and K(2)=0 in RAM 203, then in step S66 the first feed motor 206 is switched to high-speed driving. That is, the intermediate roller 15 and the feed roller 3 rotate at 20 inches / sec. The amount of rotation of the intermediate roller 15 and the feed roller 3 after the downstream leading edge of the second recording medium P in the transport direction is detected by the recording medium detection sensor 16 is controlled. As a result, in step S67, the downstream leading edge of the second recording medium P in the transport direction stops 10 mm before the transport nip. Then, in step S68, the "Feed 1 from the second transport path" subroutine is completed, and the process returns to the overall sequence of FIG. 12, and in step S8 the process proceeds to the printing operation subroutine.

[0166] The "printing operation" subroutine will be described with reference to Figure 15. If it is determined in step S15 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (currently N=3), it is determined in step S19 whether a predetermined condition, which will be described later, is met. If it is determined in step S19 that the predetermined condition is not met, the process proceeds to step S210, where it moves to the stacking state release subroutine.

[0167] The "overlap state release" subroutine will be described with reference to FIG. 18. In step S211, the value of F in RAM 203 is checked. If F=0, i.e., if it is determined that the recording on the recording medium P is the first side, then in step S212, it is determined whether the value of P stored in RAM 203 is 0. Since 1 is currently stored, the process proceeds to step S224. If it is determined in step S224 that the image formation operation for the last line of the third recording medium P has been completed, then in step S225, the third recording medium P is conveyed at 18 inches / sec by the conveyance roller 5 and the discharge roller 10. If it is determined in step S226, based on the amount of rotation of the conveyance roller 5 since the start of the indexing operation and the length of the paper, that the upstream edge of the third recording medium P in the conveyance direction has passed the spur 12, then the drive of the conveyance motor 205 is stopped in step S227. Because the feed motor 206 is not driven until the drive of the conveyance motor 205 is stopped, the downstream edge of the second recording medium P in the conveyance direction remains stopped at a position 10 mm before the conveyance nip. This eliminates the overlapping state between the third recording medium P and the second recording medium P. Furthermore, in step S228, the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec, so that the third recording medium P continues to be conveyed until the upstream end in the conveying direction reaches a position 5 mm upstream in the conveying direction from the nip portion of the reversing roller 9.

[0168] In step S229, the feed roller 3 is driven at 15 inches / sec, causing the leading edge of the second recording medium P to abut against the conveyance nip portion, and performing a skew correction operation on the second recording medium P. In step S230, the second recording medium P is cue-aligned based on the recording data. That is, by controlling the rotation amount of the conveyance roller 5, the second recording medium P is conveyed to the recording start position based on the position of the conveyance roller 5 based on the recording data. Then, in step S231, the feed motor 206 is switched to low-speed driving, and the feed roller 3 is rotated at 7.6 inches / sec.

[0169] In step S232, the reversing roller 9 and intermediate roller 15 are continuously driven in the reverse direction at 18 inches / sec. As a result, the third recording medium P is conveyed by the reversing roller 9 and intermediate roller 15 along the guide within the second conveying path 101. Then, in step S233, the third recording medium P is conveyed by the reversing roller 9 and intermediate roller 15 until its downstream leading edge in the conveying direction reaches a position 5 mm before the first conveying path 100, where it stops. Thereafter, the process returns to step S170 in FIG. 15, and the processes from step S170 onwards are performed on the second recording medium P.

[0170] If it is determined in step S19 that the predetermined conditions are met, the value of F in RAM 203 is checked in step S20, and if it is determined that F=0, that is, that the recording on recording medium P is the first side, it is determined in step S21 whether the value of P stored in RAM 203 is 0. Since 1 is currently stored, the process proceeds to step S80 to proceed to the "Printing Operation 2" subroutine.

[0171] The "Printing Operation 2" subroutine will be described with reference to FIG. 16. In step S81, it is determined whether the final line image formation operation on the third recording medium P has started. If the image formation operation has started, in step S82, the downstream leading edge of the second recording medium P in the conveying direction is abutted against the conveying nip portion while maintaining the overlapping state, thereby performing skew correction on the second recording medium P. Then, in step S83, if it is determined that the final line image formation operation on the third recording medium P has finished, in step S84, the second recording medium P is aligned based on the recording data while maintaining the overlapping state with the third recording medium P. That is, by controlling the rotation amount of the conveying roller 5, the second recording medium P is conveyed to the recording start position based on the position of the conveying roller 5 based on the recording data. In step S85, the feed motor 206 is switched to low-speed driving, and in step S86, the "Printing Operation 2" subroutine is terminated, and the process returns to step S170 in the "Printing Operation" subroutine of FIG. 15.

[0172] In step S170, the recording operation is started by ejecting ink from the recording head 7 based on the recording data for the fourth page onto the second side of the second recording medium P. Specifically, the recording operation on the second side of the second recording medium P is performed by repeating a transport operation in which the transport roller 5 intermittently transports the second recording medium P, and an image forming operation (ink ejection operation) in which the carriage 1 is moved and ink is ejected from the recording head 7. Then, in step S24, F=1 is stored in RAM 203 to record that the recording operation has been performed on the second side of the recording medium P, and the printing operation subroutine ends in step S25.

[0173] Returning to the overall sequence of Fig. 12, in step S210 it is determined whether F stored in RAM 203 is 0. Since F = 1 at the current stage, when it is determined in step S181 that the upstream end of the third recording medium P in the transport direction has passed the spur 12, in step S182 the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec. The forward drive is continued until the upstream end of the third recording medium P in the transport direction reaches a position 5 mm upstream of the nip portion of the reversing roller 9 in the transport direction.

[0174] In step S183, the reversing roller 9 and the intermediate roller 15 are continuously driven in the reverse direction at 18 inches / sec. As a result, the third recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 along the guide in the second conveying path 101. Then, in step S184, the third recording medium P is conveyed by the reversing roller 9 and the intermediate roller 15 until its downstream leading edge in the conveying direction reaches a position 5 mm before the first conveying path 100, where it stops, and the process proceeds to step S5.

[0175] If it is determined in step S5 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (N=3 at the current stage), it is determined in step S6 whether F in RAM 203 is 1. Since F=1 at the current stage, it is determined in step S7 whether there is recording data for the seventh page and beyond. In this embodiment, there is no recording data, so in step S150 the process proceeds to the "Feed 2 from the second conveying path" subroutine.

[0176] The "Feeding 2 from the Second Conveying Path" subroutine will be described with reference to FIG. 14. In step S151, it is determined whether the timing has come for the intermediate roller 15 to start feeding the third recording medium P from the second conveying path 101. When the recording medium P being recorded on by the recording head 7 is being fed from the second conveying path 101 and the subsequent recording medium P is also being fed from the second conveying path 101, the timing for the intermediate roller 15 to start feeding is as follows: Based on the amount of rotation of the conveying roller 5 from the start of the cueing operation and the length of the paper, the feeding start timing is when the distance between the upstream end of the second recording medium P in the conveying direction and the downstream front end of the third recording medium P in the second conveying path 101 reaches a positional relationship of 10 mm. Based on this relationship, the drive of the intermediate roller 15 is started so that the intermediate roller 15 starts feeding the third recording medium P from the second conveying path 101. In step S152, the feeding operation of the third recording medium P is started from the second conveying path 101. Specifically, the first feed motor 206 is driven in the second drive switching state in a low-speed reverse direction. This causes the intermediate roller 15 and the feed roller 3 to rotate at 7.6 inches / sec. The intermediate roller 15 and the feed roller 3 then feed the third recording medium P toward the recording head 7. In step S153, P=1 is stored in the RAM 203 to record that the recording medium P has been fed from the second conveying path 101.

[0177] In step S154, when the recording medium detection sensor 16 detects the downstream leading edge of the third recording medium P in the conveyance direction, it is determined in step S155 whether there is recording data for the seventh page and beyond. In this embodiment, there is no recording data for the seventh page and beyond, but the case where there is is described below.

[0178] If it is determined in step S155 that there is print data for the 7th page and onward, the process proceeds to step S160, where it is determined whether S(2)=0 and S(4)=0 in RAM 203. If it is determined that either one is 1, there is a possibility that the preceding and succeeding recording media cannot be superimposed due to curling of the recording media P, so the first feed motor 206 is not switched to high-speed drive. Therefore, the intermediate roller 15 and feed roller 3 remain driven synchronously with the conveying roller 5 at 7.6 inches / sec, and the process proceeds to step S158.

[0179] Then, in step S158, the amount of rotation of the feed roller 3 is controlled after the downstream leading edge in the transport direction of the fourth recording medium P is detected by the recording medium detection sensor 16. As a result, when the downstream leading edge in the transport direction of the fourth recording medium P reaches a position 10 mm before the transport nip portion, transport of the fourth recording medium P is stopped. Then, in the next step S159, the "Feed 2 from the second transport path" subroutine is completed, and the process returns to the overall sequence of FIG. 12, and in step S8, the process moves to the printing operation subroutine.

[0180] If it is determined in step S160 that S(2)=0 and K(4)=0 in RAM 203, then in step S157 the first feed motor 206 is switched to high-speed driving. That is, the intermediate roller 15 and the feed roller 3 rotate at 20 inches / sec. The amount of rotation of the intermediate roller 15 and the feed roller 3 after the downstream leading edge of the fourth recording medium P in the transport direction is detected by the recording medium detection sensor 16 is controlled. As a result, in step S158, the downstream leading edge of the fourth recording medium P in the transport direction stops at a position 10 mm before the transport nip. Then, in step S159, the "Feed 2 from the second transport path" subroutine is completed, and the process returns to the overall sequence of FIG. 12, and in step S8 the process proceeds to the printing operation subroutine.

[0181] In this embodiment, since there is no print data for pages 7 and beyond, if it is determined in step S155 that there is no print data for pages 7 and beyond, the process proceeds to step S156, where it is determined whether K(2)=0 and K(3)=0 in RAM 203. If it is determined that either one is 1, there is a possibility that the preceding and succeeding print media cannot be superimposed due to curling of the print media P, so the first feed motor 206 is not switched to high-speed drive. Therefore, the intermediate roller 15 and the feed roller 3 remain driven synchronously with the conveyance roller 5 at 7.6 inches / sec, and the process proceeds to step S158.

[0182] Then, in step S158, the amount of rotation of the feed roller 3 is controlled after the downstream leading edge of the third recording medium P in the transport direction is detected by the recording medium detection sensor 16. As a result, when the downstream leading edge of the third recording medium P in the transport direction reaches a position 10 mm before the transport nip portion, the transport of the third recording medium P is stopped. Then, in the next step S159, the "Feed 2 from the second transport path" subroutine is ended.

[0183] If it is determined in step S160 that K(2)=0 and K(3)=0 in RAM 203, then in step S157 the first feed motor 206 is switched to high-speed driving. That is, the intermediate roller 15 and the feed roller 3 rotate at 20 inches / sec. The amount of rotation of the intermediate roller 15 and the feed roller 3 after the downstream leading edge of the third recording medium P in the transport direction is detected by the recording medium detection sensor 16 is controlled. As a result, in step S158, the downstream leading edge of the third recording medium P in the transport direction stops at a position 10 mm before the transport nip. Then, in step S159, the "Feed 2 from the second transport path" subroutine is completed, and the process returns to the overall sequence of FIG. 12, and in step S8 the "Printing operation" subroutine is started.

[0184] The "printing operation" subroutine will be described with reference to Figure 15. If it is determined in step S15 that the number of recording media P fed from the paper stacking unit 11 in one job is not one (currently N=3), it is determined in step S19 whether a predetermined condition, which will be described later, is met. If it is determined in step S19 that the predetermined condition is not met, the process proceeds to step S210 to proceed to the "overlap state release" subroutine.

[0185] The "overlap state release" subroutine will be described with reference to Figure 18. In step S211, the value of F in RAM 203 is checked, and if it is determined that F=1, that is, that recording on recording medium P is on the second side, it is determined in step S234 whether the value of P stored in RAM 203 is 0. Since 1 is currently stored, the process proceeds to step S244.

[0186] If it is determined in step S244 that the image formation operation for the last line on the second recording medium P has been completed, then in step S245 the second recording medium P is conveyed at 18 inches / sec by the conveyance rollers 5 and discharge rollers 10. If it is determined in step S246 from the amount of rotation of the conveyance rollers 5 since the start of the indexing operation and the length of the paper that the upstream end of the second recording medium P in the conveyance direction has passed the spurs 12, then driving of the conveyance motor 205 is stopped in step S247. Since the feed motor 206 is not driven until driving of the conveyance motor 205 is stopped, the downstream leading edge of the third recording medium P in the conveyance direction remains stopped at a position 10 mm before the conveyance nip. This eliminates the overlapping state of the second and third recording media P.

[0187] In step S248, the feed roller 3 is driven at 15 inches / sec, causing the leading edge of the third recording medium P to abut against the conveyance nip portion, and skew correction of the third recording medium P is performed, and in step S249, the third recording medium P is cue-aligned based on the recording data. That is, by controlling the rotation amount of the conveyance roller 5, the third recording medium P is conveyed to the recording start position based on the position of the conveyance roller 5 based on the recording data. Then, in step S250, the feed motor 206 is switched to low-speed drive, and the feed roller 3 is rotated at 7.6 inches / sec.

[0188] Thereafter, the process returns to step S173 in FIG. 15, and the processes from step S173 onward are performed on the third recording medium P and the second recording medium P.

[0189] If it is determined in step S19 that the predetermined conditions are met, the value of F in RAM 203 is checked in step S20, and if it is determined that F=1, that is, that the recording on recording medium P is the second side, it is determined in step S172 whether the value of P stored in RAM 203 is 0. Since 1 is currently stored, the process proceeds to step S70 to proceed to the "Printing Operation 1" subroutine.

[0190] The "Printing Operation 1" subroutine will be described with reference to FIG. 16. In step S71, it is determined whether the operation of forming the final line of an image on the second recording medium P has started. If the image forming operation has started, in step S72, the downstream leading edge of the third recording medium P in the conveying direction is abutted against the conveying nip portion while maintaining the overlapping state, thereby performing a skew correction operation on the third recording medium P. Then, in step S73, if it is determined that the operation of forming the final line of an image on the second recording medium P has finished, in step S74, the third recording medium P is aligned based on the recording data while maintaining the overlapping state with the second recording medium P. That is, by controlling the rotation amount of the conveying roller 5, the third recording medium P is conveyed to the recording start position based on the position of the conveying roller 5 based on the recording data. In step S75, the feed motor 206 is switched to low-speed driving, and in step S76, the "Printing Operation 1" subroutine is terminated, and the process returns to step S173 in the "Printing Operation" subroutine of FIG. 15.

[0191] In step S173, the recording operation is started by ejecting ink from the recording head 7 onto the second side of the third recording medium P based on the recording data for the sixth page. Specifically, the recording operation on the second side of the third recording medium P is performed by repeating a conveying operation in which the conveying roller 5 intermittently conveys the third recording medium P, and an image forming operation (ink ejection operation) in which the carriage 1 is moved and ink is ejected from the recording head 7. Then, in step S174, F=1 is stored in RAM 203 to record that the recording operation on the second side of the recording medium P has been performed, and the process proceeds to the "discharge operation 1" subroutine in step S130.

[0192] The "discharge operation 1" subroutine will be described with reference to Figure 17. In step S121, if it is determined from the amount of rotation of the transport roller 5 since the start of the cueing operation and the length of the paper that the upstream end of the second sheet of recording medium P in the transport direction has passed the spur 12, then in step S122 the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec. Then, in step S123 the second sheet of recording medium P is discharged outside the apparatus, and in step S124 the "discharge operation 1" subroutine ends. Then, the process returns to step S175 in the "printing operation" subroutine of Figure 15, where it is determined in step S175 whether there is record data for pages 7 and beyond. If it is determined that there is no record data, then in step S130 the process proceeds to the "discharge operation 2" subroutine.

[0193] The "discharge operation 2" subroutine will be described with reference to Figure 17. In step S131, if it is determined from the amount of rotation of the transport roller 5 since the start of the cueing operation and the length of the paper that the upstream end of the third sheet of recording medium P in the transport direction has passed the spur 12, in step S132 the reversing roller 9 is continuously driven in the forward direction at 18 inches / sec. Then, in step S133 the third sheet of recording medium P is discharged outside the apparatus, and in step S134 the "discharge operation 2" subroutine ends. Then the process returns to step S176 in the "printing operation" subroutine in Figure 15, and the double-sided printing operation ends in step S176.

[0194] 21 and 22 are diagrams illustrating the operation of overlapping a subsequent recording medium on a preceding recording medium in this embodiment. The operation of forming the overlapping state in which the leading end of the subsequent recording medium overlaps the trailing end of the preceding recording medium, as described with reference to FIGS. 2 to 11, will be described.

[0195] 21 and 22 are enlarged views of the area between the feeding nip formed by the feeding roller 3 and the feeding driven roller 4, and the conveying nip formed by the conveying roller 5 and the pinch roller 6. In this embodiment, a configuration including a recording medium pressing lever that prevents the rear end of the recording medium P from floating up will be described.

[0196] The process in which a recording medium is transported by the transport roller 5 and the feed roller 3 will be explained in order as three states. The first state, in which the subsequent recording medium follows the preceding recording medium, will be explained with reference to ST30 and ST31 in Fig. 21. The second state, in which the subsequent recording medium is overlapped on the preceding recording medium, will be explained with reference to ST32 and ST33 in Fig. 22. The third state, in which it is determined whether to maintain the overlapping state and perform skew correction of the subsequent recording medium, will be explained with reference to ST34 in Fig. 22.

[0197] In ST30 in Figure 21, the feed roller 3 is controlled to transport the subsequent recording medium P, and the recording medium detection sensor 16 detects the leading edge of the subsequent recording medium P. The first section A1 is defined as the distance from the recording medium detection sensor 16 to position P1 where the subsequent recording medium P can be placed on top of the preceding recording medium P. In the first section A1, the leading edge of the subsequent recording medium P follows the trailing edge of the preceding recording medium P. P1 is determined by the configuration of the mechanism.

[0198] In the first state, there are cases where the chasing operation is stopped in the first section A1. As in ST31 in Figure 21, if the leading edge of the succeeding recording medium P overtakes the trailing edge of the preceding recording medium P before P1, the operation of overlapping the succeeding recording medium on the preceding recording medium is not performed.

[0199] 22, a second section A2 is defined as the section from the aforementioned P1 to position P2 where the recording medium presser lever 17 is provided. In the second section A2, the operation of overlapping the succeeding recording medium P on the preceding recording medium P is performed.

[0200] In the second state, there are cases where the operation of overlapping the succeeding recording medium on the preceding recording medium is stopped in the second section A2. As shown in ST33 of Figure 22, if the leading edge of the succeeding recording medium P cannot catch up with the trailing edge of the preceding recording medium P in the second section A2, the operation of overlapping the succeeding recording medium on the preceding recording medium cannot be performed.

[0201] In ST34 of FIG. 22, the section from P2 to P3 described above is defined as a third section A3. P3 is, as an example, the leading edge position of the succeeding recording medium P when it stops in step S45 of FIG. 13. The succeeding recording medium P is transported while overlapping the preceding recording medium P until its leading edge reaches P3. In the third section A3, it is determined whether to abut the succeeding recording medium P against the transport nip portion while maintaining the overlapping state and perform cueing. In other words, it is determined whether to maintain the overlapping state and perform cueing after the skew correction operation, or to release the overlapping state and perform cueing after the skew correction operation.

[0202] 23 is a flowchart illustrating the operation of correcting skew of the succeeding recording medium in this embodiment. The determination of whether the predetermined condition is met as explained in S19 of FIG.

[0203] We will explain the determination operation of whether to perform skew correction by abutting the leading edge of the subsequent recording medium P against the transport nip portion while maintaining the overlapping state of the preceding recording medium P and the subsequent recording medium P, or to release the overlapping state of the preceding recording medium P and the subsequent recording medium P and then abutting the leading edge of the subsequent recording medium P against the transport nip portion to perform skew correction.

[0204] The process starts with step S301. In step S302, it is determined whether the leading edge of the succeeding recording medium P has reached the determination position (P3 in ST34 in FIG. 22). If it has not reached this position (step S302: NO), it is unclear whether the leading edge of the succeeding recording medium P will strike the transport nip portion with the specified amount of transport, so it is decided to perform skew correction operation on the succeeding recording medium only (step S303), and the determination operation ends (step S304). In other words, after the trailing edge of the preceding recording medium P passes the transport nip portion, the succeeding recording medium P alone is struck against the transport nip portion to perform skew correction operation, and then the cue is performed with only the succeeding recording medium P.

[0205] On the other hand, if the leading edge of the succeeding recording medium P has reached the determination position P3 (step S302: YES), it is determined whether the trailing edge of the preceding recording medium P has passed through the transport nip portion (step S305). If it is determined that it has passed through (step S305: YES), the preceding and succeeding recording media do not overlap, so it is decided to perform skew correction operation on only the succeeding recording medium (step S306). That is, only the succeeding recording medium P is abutted against the transport nip portion to perform skew correction operation, and then the cue is performed with only the succeeding recording medium P.

[0206] On the other hand, if it is determined that the trailing edge of the preceding recording medium P has not passed through the transport nip portion (step S305: NO), it is determined whether the overlap amount between the trailing edge of the preceding recording medium P and the leading edge of the following recording medium P is smaller than a threshold (step S307). The position of the trailing edge of the preceding recording medium P is updated as the recording operation on the preceding recording medium P is performed. The leading edge of the following recording medium P is at the aforementioned determined position. In other words, the overlap amount decreases as the recording operation on the preceding recording medium P is performed. If it is determined that the overlap amount is smaller than the threshold (step S307: YES), the overlapping state is released and a skew correction operation is performed on the following recording medium only (step S308). In other words, after the image formation operation on the preceding recording medium P is completed, the following recording medium P is not transported together with the preceding recording medium P. Specifically, the transport motor 205 drives the transport roller 5 to transport the preceding recording medium P. However, the feed roller 3 is not driven. Therefore, the overlapping state is released. Furthermore, only the succeeding recording medium P is abutted against the conveyance nip portion to perform the skew correction operation, and then the cue is adjusted with only the succeeding recording medium P remaining.

[0207] If it is determined that the overlap amount is equal to or greater than the threshold (step S307: NO), it is determined whether the succeeding recording medium P will reach the spur 12 when the cue of the succeeding recording medium P is fed (step S309). If it is determined that the succeeding recording medium P will not reach the spur 12 (step S309: NO), the overlapping state is released and a decision is made to perform skew correction operation on only the succeeding recording medium P (step S310). In other words, after the image forming operation on the preceding recording medium P is completed, the succeeding recording medium P is not transported together with the preceding recording medium P. Specifically, the transport motor 205 drives the transport roller 5 to transport the preceding recording medium P. However, the feed roller 3 is not driven. Therefore, the overlapping state is released. Furthermore, only the succeeding recording medium P is abutted against the transport nip portion to perform skew correction operation, and then the cue is fed with only the succeeding recording medium P.

[0208] If it is determined that the succeeding recording medium P reaches the spur 12 (step S309: YES), it is determined whether there is a gap between the last line of the preceding recording medium and the line preceding that last line (step S311). If it is determined that there is no gap (step S311: NO), the overlapping state is released and a skew correction operation is performed on only the succeeding recording medium (step S312). If it is determined that there is a gap (step S311: YES), the skew correction operation is performed on the succeeding recording medium P while maintaining the overlapping state, and then the leading edge is aligned. That is, after the image forming operation on the leading recording medium P is completed, the succeeding recording medium P is abutted against the conveyance nip portion while still overlapping with the leading recording medium P. Specifically, the conveyance motor 205 and the feed motor 206 are driven simultaneously to rotate the conveyance roller 5 and the feed roller 3. After the skew correction operation, the succeeding recording medium P is aligned while still overlapping with the leading recording medium P.

[0209] In this way, a determination operation is performed as to whether to maintain or release the overlapping state of the preceding recording medium P and the succeeding recording medium P.

[0210] FIG. 24 is a flowchart for explaining the configuration for calculating the leading edge position of the subsequent recording medium after cueing in this embodiment.

[0211] The process starts in step S401. In step S402, the recordable area of ​​the recording medium size is read. The leading edge recordable position, i.e., the top edge margin, is identified, and the top edge margin of the recordable area is set to the leading edge position (step S403). Here, the leading edge position is defined as the distance from the conveying nip portion.

[0212] Next, the first recording data is read (step S404). This identifies the position of the first recording data from the leading edge of the recording medium (detection of non-recording area), so it is determined whether the distance from the leading edge of the recording medium to the first recording data is greater than the previously set leading edge position (step S405). If the distance from the leading edge of the recording medium to the first recording data is greater than the previously set leading edge position (step S405: YES), the leading edge position is updated to the distance from the leading edge of the recording medium to the first recording data (step S406). If the distance from the leading edge of the recording medium to the first recording data is equal to or less than the previously set leading edge position (step S405: NO), the process proceeds to step S407.

[0213] Next, an initial carriage movement command is generated (step S407). Next, it is determined whether the recording medium transport amount for the initial carriage movement is greater than the previously set leading edge position (step S408). If the recording medium transport amount for the initial carriage movement is greater than the previously set leading edge position (step S408: YES), the leading edge position is updated to the recording medium transport amount for the initial carriage movement (step S409). If the recording medium transport amount for the initial carriage movement is equal to or less than the previously set leading edge position (step S408: NO), the leading edge position is not updated. As described above, the leading edge position of the subsequent recording medium P is determined (step S410), and the process ends (step S411). Based on the determined leading edge position, it is possible to determine whether the subsequent recording medium P will reach the spur 12 when it is cue-aligned (FIG. 23: step S309).

[0214] As described above, according to the above embodiment, it is possible to control the leading edge of the succeeding recording medium to overlap the trailing edge of the preceding recording medium regardless of whether the recording medium is supplied from the paper stacking section or the second conveying path.

[0215] In the above-described embodiment, the recording medium P is discharged from the apparatus by being conveyed downstream in the conveying direction by the reversing rollers 9 that reverse the conveying direction of the recording medium. However, the same effect can be obtained by providing a discharge path between the reversing rollers 9 and the discharge rollers 10 that conveys the recording medium P to the outside of the apparatus, and by providing a conveying direction switching member that switches the direction of the recording medium P between the reversing rollers 9 and the discharge path.

[0216] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more of the functions.

[0217] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0218] 1: carriage, 2: pickup roller, 3: feeding roller, 4: feeding driven roller, 5: transport roller, 6: pinch roller, 7: recording head, 8: platen, 9: reversing roller, 10: discharge roller, 11: paper stacking section, 12: spur, 13: reversing driven roller, 14: intermediate driven roller, 15: intermediate roller, 16: recording medium detection sensor, 17: recording medium presser lever, 100: first transport path, 101: second transport path, P: recording medium

Claims

1. A supply means for supplying a recording medium; an intermediate roller for conveying the recording medium supplied by the supply means; a conveying roller that conveys the recording medium conveyed by the intermediate roller in a conveying direction; a recording means for recording an image on the recording medium conveyed by the conveying rollers, the recording means being disposed downstream of the conveying rollers; a reversing path for returning the recording medium, which has been recorded on and turned over by the recording means, to the intermediate roller, a first control for overlapping a second recording medium supplied from the supply means with a first recording medium being recorded by the recording means between the intermediate roller and the conveying roller; a second control for overlapping a second recording medium conveyed from the reversing path between the intermediate roller and the conveying roller with respect to the first recording medium on which recording is being performed by the recording means; A recording apparatus comprising a control means capable of carrying out the above.

2. a discharge path for discharging the recording medium on which an image has been recorded, the discharge path being located downstream of the recording means in the transport direction; 2. The recording device according to claim 1, further comprising a reversing roller disposed in the discharge path, the reversing roller rotating in a first direction to discharge the recording medium and rotating in a second direction opposite to the first direction to transport the recording medium recorded by the recording means to the reversing path.

3. A guide portion is provided between the intermediate roller and the conveying roller, 3. The recording apparatus according to claim 1, wherein the intermediate roller transports the recording medium from the reversing path to the guide section.

4. The recording device as described in claim 1, characterized in that it is further characterized by comprising a detection sensor provided between the intermediate roller and the conveying roller for detecting an end of the recording medium.

5. The recording device described in Claim 1, characterized in that the control means performs a skew correction operation in which the second recording medium transported from the reversal path is abutted against the transport roller when the transport roller is stopped.

6. 6. The recording apparatus according to claim 1, wherein the control means determines whether or not to perform control for overlapping the second recording medium on the rear end of the first recording medium based on recording data.

7. 7. The recording apparatus according to claim 6, wherein the recording data is a print density in a preset recording area.

8. The recording device according to claim 7, characterized in that the control means determines whether or not to perform control to overlap the second recording medium on the rear end of the first recording medium based on the recording data of the predetermined area where the first recording medium and the second recording medium overlap each other.

9. The recording apparatus according to claim 7 or 8, characterized in that the control means determines whether or not to perform control to overlap the second recording medium with the rear end of the first recording medium by comparing the print density of the predetermined area with a predetermined print density.

10. The recording apparatus according to claim 9, characterized in that the control means determines to perform control to overlap the second recording medium with the rear end of the first recording medium when the print density of the predetermined area is within the predetermined print density.

11. 11. The recording apparatus according to claim 7, wherein the preset recording area is a first area at a leading end of the recording medium and a second area at a trailing end of the recording medium.

12. The recording device according to claim 3, characterized in that the control means causes the second recording medium to catch up with the first recording medium by setting the transport speed of the intermediate roller transporting the second recording medium faster than that of the transport roller while the first recording medium is being transported by the transport roller.

13. The recording device according to claim 2, characterized in that the control means releases the overlapping state between the rear end of the first recording medium and the front end of the second recording medium by setting the transport speed of the reversing roller in the first direction to a speed faster than that of the transport roller that transports the second recording medium on which recording is being performed by the recording means.

14. 14. The recording apparatus according to claim 1, wherein the control means detects the leading edge position of the second recording medium before the recording means performs a recording operation of the final line on the first recording medium.

15. A recording device as described in any one of claims 1 to 14, characterized in that when the control means determines not to control the leading end of the second recording medium to overlap the trailing end of the first recording medium, the control means stops transporting the second recording medium and transports the first recording medium to a position opposite the recording means.

16. A method for controlling a recording device including a supply means for supplying a recording medium, an intermediate roller for transporting the recording medium supplied by the supply means, a transport roller for transporting the recording medium transported by the intermediate roller in a transport direction, a recording means for recording an image on the recording medium transported by the transport roller downstream of the transport roller, and an inversion path for returning the recording medium that has been recorded on and inverted by the recording means to the intermediate roller, comprising: a first control for overlapping a second recording medium supplied from the supply means with a first recording medium being recorded by the recording means between the intermediate roller and the conveying roller; a second control for overlapping a second recording medium conveyed from the reversing path between the intermediate roller and the conveying roller with respect to the first recording medium on which recording is being performed by the recording means; 4. A method for controlling a recording apparatus, comprising the steps of:

17. A discharge path is provided downstream of the recording means in the conveying direction, for discharging the recording medium on which an image is recorded, 17. The control method for a recording device according to claim 16, further comprising a reversing roller disposed in the discharge path, the reversing roller rotating in a first direction to discharge the recording medium and rotating in a second direction opposite to the first direction to transport the recording medium recorded by the recording means to the reversing path.

18. A guide portion is provided between the intermediate roller and the conveying roller, 18. The method for controlling a recording apparatus according to claim 16, wherein the intermediate roller transports the recording medium from the reversing path to the guide section.

19. The method for controlling a recording device according to claim 16, further comprising a detection sensor provided between the intermediate roller and the transport roller for detecting an edge of the recording medium.

20. A control method for a recording device as described in Claim 16, characterized in that in the control process, when the conveying roller is stopped, a skew correction operation is performed in which the second recording medium conveyed from the reversal path is abutted against the conveying roller.

21. A control method for a recording device described in any one of claims 16 to 20, characterized in that in the control process, it is determined whether or not to control the second recording medium to be overlapped on the rear end of the first recording medium based on recording data.

22. The method for controlling a recording device according to claim 21, wherein the recording data is a print density in a preset recording area.

23. The control method for a recording device described in Claim 22, characterized in that in the control process, it is determined whether or not to control the overlapping of the second recording medium on the rear end of the first recording medium based on the recording data of the predetermined area where the first recording medium and the second recording medium overlap each other.

24. A control method for a recording device as described in Claim 22 or 23, characterized in that in the control process, by comparing the printing density of the predetermined area with a predetermined printing density, it is determined whether or not to perform control to overlap the second recording medium on the rear end of the first recording medium.

25. The control method for a recording device described in Claim 24, characterized in that in the control process, when the print density of the predetermined area is within the predetermined print density, it is determined to perform control to overlap the second recording medium on the rear end of the first recording medium.

26. A program for causing a computer to execute the recording apparatus control method according to claim 16.

27. A computer-readable storage medium storing a program for causing a computer to execute the recording device control method according to claim 16.

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