Liquid dispensing device and end detection method

Abstract

This technology provides high-precision detection of the edges of paper. [Solution] The carriage is moved at a constant speed until it hits the abutment part, while detecting the edge of the recording medium with a high-precision sensor.

Description

Technical Field

[0001] The present invention relates to a serial liquid ejection device and an end detection method.

Background Art

[0002] In a serial liquid ejection device, it is required to accurately detect the paper width and the paper edge.

[0003] Patent Document 1 discloses a technique in which a reflection type optical sensor provided on a carriage detects the edge of a recorded image and the edge of a paper, and based on the detection result, changes the recording scan start position during a recording operation.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] With the recent miniaturization of devices, the moving range of the carriage has been approaching the width area of the paper. Under such circumstances, it is necessary for the carriage to decelerate before the moving limit position.

[0006] However, if the carriage is decelerated sufficiently before the moving limit position, the edge of the paper will be detected while the carriage is decelerating. In this case, hunting occurs in the detection result, making it difficult to accurately detect the edge position.

[0007] Therefore, the present invention provides a technique for accurately detecting the edge of a paper in a serial liquid ejection device.

Means for Solving the Problems

[0008] Therefore, the liquid dispensing device of the present invention comprises: a conveying means for conveying a sheet in a conveying direction; a carriage equipped with a liquid dispensing head and capable of reciprocating movement in a scanning direction intersecting the conveying direction; a first abutment portion capable of contacting the carriage at the reference side limit position of the carriage in the scanning direction; a second abutment portion capable of contacting the carriage at the non-reference side limit position of the carriage opposite to the reference side in the scanning direction; a first detection means provided at the non-reference end of the carriage for detecting the end position of a recording medium while moving together with the carriage; and a control means for controlling the movement of the carriage and the first detection means, wherein the control means moves the carriage at a constant speed until the carriage abuts the first abutment portion when the first detection means detects the end position of the reference side of the recording medium. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a technology for detecting the edges of paper with high precision. [Brief explanation of the drawing]

[0010] [Figure 1] This is an external perspective view showing a liquid dispensing device. [Figure 2] This is a schematic diagram showing the internal mechanism of a liquid dispensing device. [Figure 3] This diagram shows the carriage in contact with the abutment. [Figure 4] This is a block diagram showing the control unit in a liquid dispensing device. [Figure 5] This graph shows the carriage movement speed in a typical liquid dispensing device. [Figure 6] This graph shows the change in the carriage's movement speed. [Figure 7] This is a diagram showing a modified example. [Figure 8] (a) is a diagram showing the carriage, and (b) is a graph showing the detection results. [Figure 9]This diagram shows the positional relationship between the carriage and the detection unit. [Figure 10] This diagram shows the positional relationship between the carriage and the detection unit. [Figure 11] This is a flowchart illustrating the recording process. [Figure 12] This diagram shows the carriage and a low-precision sensor. [Figure 13] This is a flowchart illustrating the recording process. [Modes for carrying out the invention]

[0011] A first embodiment of the present invention will be described below with reference to the drawings.

[0012] Figure 1 is an external perspective view showing the liquid ejection device 1 according to this embodiment. The liquid ejection device 1 is an inkjet recording device that ejects liquid ink to record onto a recording medium, but the present invention is also applicable to various liquid ejection devices other than inkjet recording devices. Hereinafter, the X direction is the carriage scanning direction, the Y direction is the (effective) transport direction, and the Z direction is the vertically upward direction.

[0013] Furthermore, "recording" includes not only cases where meaningful information such as characters and figures is formed, but also broadly cases where images, patterns, etc. are formed on a recording medium, or where the medium is processed, regardless of whether it is meaningful or not, and does not depend on whether or not it is manifested in a way that can be perceived visually by humans.In addition, in this embodiment, a sheet of paper is assumed as the "recording medium," but it may also be cloth, plastic film, etc.

[0014] The liquid ejection device 1 has an overall flat rectangular parallelepiped appearance, and includes a device main body 2 and a main body cover portion 3 composed of a plurality of covers. The main body cover portion 3 is provided so as to cover the device main body 2 and constitutes the top portion of the liquid ejection device 1. The main body cover portion 3 has a paper feed cover 8 for setting a recording medium, an access cover 5 for performing maintenance work inside the device, and a tank access cover 9 for covering a portion for supplying ink to the tank of the device. Further, a reading unit (scanner unit) 4 for reading an image of a document is provided in the main body cover portion 3, and the entire reading unit 4 can be opened and closed and moved in the same manner as the access cover 5 to perform maintenance work inside the device.

[0015] In the liquid ejection device 1, a discharge portion 6 for discharging a recorded recording medium is formed. Further, an operation unit 7 for receiving an operation of an operator is provided in the liquid ejection device 1. The operation unit 7 includes a display portion in a touch panel format, receives an input operation of the operator, and displays information to the operator. Also, the liquid ejection device 1 includes a notification unit 10 and can perform a sound notification for an operation on each portion. Further, the liquid ejection device 1 includes a waste liquid tank portion 11 for inserting a waste liquid tank.

[0016] FIG. 2 is a schematic diagram showing the internal mechanism of the liquid ejection device 1. The liquid ejection device 1 includes a conveyance unit 21, a conveyance sensor 23, a paper feed unit 20, a recording unit 26, and a cutter unit 29, and records an image on a recording medium PM. The recording medium PM is stored in the paper feed unit 20. The paper feed unit 20 is configured to be capable of accommodating, as a target (hereinafter referred to as a recording target) selected as the recording medium PM, a cut sheet having a size conforming to a predetermined standard and a roll sheet in which a long sheet is wound in a roll shape, respectively.

[0017] In this embodiment, the paper feeding unit 20 includes a cut sheet loading unit 20a configured to load multiple cut sheets, and a roll sheet loading unit 20b that rotatably loads a roll sheet at a position different from the cut sheet loading unit 20a. The cut sheet loading unit 20a is located downstream of the roll sheet loading unit 20b in the transport direction d1. An example of the above-mentioned specified standard is the JIS standard (Japanese Industrial Standards). The recording operation of the roll sheet supplied from the roll sheet loading unit 20b will be described below.

[0018] The roll sheet mounting section 20b includes a holding section (not shown) that holds a roll sheet in which a continuous sheet is wound into a roll, and a drive section (not shown) that rotates the sheet held by the holding section. The roll sheet mounting section 20b supplies the roll sheet 28 in the paper feeding direction (Y direction of the arrow) and the unwinding direction (-Y direction) of the roll sheet 28 by rotating the roll sheet 28 held by the holding section. The spool member 24 is inserted into the paper core of the roll sheet 28 and is pivotally supported by the holding section of the paper feeding section 20. The paper feeding section 20 rotates the roll sheet 28 by rotating the spool member 24 with a motor (not shown).

[0019] The transport unit 21 is a transport roller for transporting the recording medium PM. In this embodiment, the transport unit 21 includes a pair of drive rollers and driven rollers. The transport unit 21 is equipped with a drive mechanism (not shown) that rotationally drives the drive rollers. The driven rollers are pressed against the drive rollers and rotate in a driven manner. Therefore, the recording medium PM is held between the drive rollers and the driven rollers and transported on the platen 22. The drive mechanism of the transport unit 21 can, for example, be a gear mechanism driven by a motor. The amount of rotation of the transport unit 21 is detected by a sensor (not shown) (e.g., an encoder), and the amount of transport of the recording medium PM is controlled.

[0020] In the following explanation, the terms "upstream" and "downstream" refer to the direction in which the recording medium PM is transported by the transport unit 21. The transport direction of the recording medium PM is the Y direction, and is sometimes called the sub-scanning direction. The X direction indicates the direction that intersects the transport direction of the recording medium PM, and this direction is sometimes called the main scanning direction or the paper width direction. The roll sheet 28 and the transport unit 21 are arranged so that their axial directions are parallel to the main scanning direction (X direction).

[0021] The transport sensor 23 is positioned upstream of the transport unit 21 in the transport direction and is a sensor such as an optical sensor that determines whether or not the roll sheet 28 is being transported properly to the transport unit 21.

[0022] The recording unit 26 is located downstream of the transport unit 21 and is configured to record images on the recording medium PM transported by the transport unit 21. In this embodiment, the recording unit 26 constitutes a recording head (liquid ejection head) equipped with multiple ejection ports for ejecting ink.

[0023] The recording unit 26 can be mounted on the carriage 25, and the carriage 25 is equipped with an ink supply tube that supplies ink to the recording unit 26. The carriage 25 is also equipped with a detection unit 27 for detecting the edges of the recording medium PM, etc. The carriage 25 is configured to reciprocate in the X direction by a drive mechanism (not shown). As the drive mechanism of the carriage 25, for example, a belt drive mechanism driven by a motor can be used. The position of the carriage 25 is detected by the detection unit 27 (not shown) or a sensor (not shown) (e.g., an encoder), and the movement of the carriage 25 is controlled accordingly.

[0024] The cutter unit 29 is equipped with a cutter and cuts the recording medium PM in the X direction. The cutter unit 29 is reciprocally movable in the X direction by a cutter motor (not shown). In one example, the cutter unit 29 may also have a pressure sensor that detects the pressure applied to the cutter.

[0025] Figure 3 shows the abutment portions 203 and 204 and the carriage 25 in contact with the abutment portion 203 in this embodiment. The carriage 25 is equipped with a detection unit 27, and the recording unit 26 mounted on the carriage 25 is equipped with an ink ejection nozzle 39. The detection unit 27 has a high-precision sensor 27b and is provided on the non-reference side (the -X direction side in the figure) of the carriage 25. The detection unit 27 can detect the end positions of the recording medium PM by passing over the upper part of both ends in the +Z direction.

[0026] In this specification, the side with the abutment portion 203 (+X direction side) will be described as the reference side, and the side with the abutment portion 204 (-X direction side) opposite to the reference side will be described as the non-reference side. The detection unit 27 may be capable of detecting not only both ends of the recording medium PM, but also images recorded on the recording medium PM, the thickness of the recording medium PM, etc. The detection unit 27 includes, for example, an optical sensor equipped with a light-emitting element and a light-receiving element. The light-emitting element irradiates light toward the platen 22, and the reflected light is received by the light-receiving element. The MPU 31 (see Figure 4), which will be described later, can detect the end position of the recording medium PM from the difference in reflectivity between the recording medium PM and the platen 22 detected by the detection unit 27.

[0027] In other words, when the carriage 25 scanning in the X direction approaches the platen 22 from the recording medium PM, the value (voltage value) received by the light-receiving element changes. A threshold value is set for this voltage value, and from the carriage position when it falls below that threshold, it becomes possible to detect the ends of the recording medium PM (reference end 201, non-reference end 202). In this embodiment, the high-precision sensor 27b constituting the detection unit 27 is a differential type sensor having one light-emitting part and multiple light-receiving parts, enabling detection with relatively high precision. In Figure 3, the carriage 25 is in contact with the abutment part 203 at the limit of movement position on the reference end 201 side of the recording medium PM. The abutment part 203 can come into contact with the carriage 25, and when the device is stopped or in standby mode, the carriage 25 is stopped (standby) in contact with the abutment part 203 on the reference end 201 side as shown in Figure 3.

[0028] In this embodiment, when the carriage 25 moves in the +X direction, the carriage 25 contacts the abutment portion 203 immediately after the detection unit 27 passes the reference end 201 of the recording medium PM. On the other hand, when the carriage 25 moves in the -X direction from the state shown in Figure 3, the carriage 25 contacts the abutment portion 204 immediately after the most reference nozzle row 39 passes the non-reference end 202 of the recording medium PM. In other words, the abutment portions 203 and 204 are positioned in such ways. This makes it possible to minimize the size of the device in the X direction.

[0029] Figure 4 is a block diagram showing the control unit 30 in the liquid dispensing device 1. The MPU 31 is a processor that controls various operations of the liquid dispensing device 1 and controls data processing, etc. The MPU 31 controls the entire liquid dispensing device 1 by executing programs stored in the memory device 32. The memory device 32 is composed of, for example, ROM or RAM. The memory device 32 stores various data necessary for processing, such as programs executed by the MPU 31 and data received from the host computer 100.

[0030] The MPU 31 controls the recording unit 26 via driver 34a. The MPU 31 controls the carriage motor 40 via driver 34b. The MPU 31 controls the transport motor 41 and the feeding motor 42 via drivers 34c and 34d. The MPU 31 acquires detection results from various sensor groups 35 provided in the liquid dispensing device 1 and performs control operations. The sensor group 35 includes a detection unit 27 and a cover detection sensor (not shown). The MPU 31 controls the display on the operation unit 36 ​​and receives information input by the operator via the operation unit 36.

[0031] The host computer 100 is, for example, a personal computer or mobile terminal (such as a smartphone or tablet) used by the operator. A printer driver 101 is installed on the host computer 100 to perform communication between the host computer 100 and the liquid dispensing device 1. The liquid dispensing device 1 is equipped with an interface unit 33, and communication between the host computer 100 and the MPU 31 is performed via the interface unit 33. For example, when the operator inputs a recording operation to the host computer 100, the printer driver 101 collects the image data to be recorded and settings related to recording (information such as the quality of the recorded image) and instructs the liquid dispensing device 1 to perform the recording operation.

[0032] Figure 5 is a graph showing the relationship between the elapsed time since the start of carriage scanning and the carriage's movement speed in a serial-type liquid dispensing device. The graph in Figure 5 also shows the width of the sheet (recording medium) and the timing 503 when the carriage contacts the abutment section 203, corresponding to the elapsed time. After accelerating to a predetermined speed, the carriage moves at a constant speed at that predetermined speed, and generally stops while decelerating before hitting the abutment section 203.

[0033] Here, we consider the case where, in order to miniaturize the device, abutment portions 203 and 204 are provided at the positions described in Figure 3. For example, when moving the carriage 25 in the +X direction, in order to stop the carriage without it hitting the abutment portion 203, the carriage 27 must be decelerated before the detection unit 27 detects the reference end 501 of the recording medium. In this case, at the timing 501 when the detection unit 27 detects the reference end 201 of the recording medium, the carriage is in a decelerated state.

[0034] However, when the detection unit 27 detects an end while the carriage speed is in the deceleration range, hunting 551 may occur in the output result of sensor 27b. As a result, accurate end detection cannot be performed, leading to a problem of reduced detection accuracy. In other words, in order to perform highly accurate end detection, the carriage must be moving at a constant velocity at the time of end detection.

[0035] On the other hand, when moving the carriage 25 in the -X direction, the movement of the carriage 25 continues even after the detection unit 27 detects the non-reference end 202, until the recording unit 26 reaches the non-reference end 202. Therefore, between the time the detection unit 27 detects the non-reference end 202 and the time the recording unit 26 moves to the non-reference end 202, the carriage can be decelerated and stopped before it contacts the abutment portion 204. For this reason, in this embodiment, on the reference side, the carriage 25 is stopped by contacting the abutment portion 203, and on the non-reference side, the carriage 25 is decelerated and stopped without contacting the abutment portion 204.

[0036] The carriage speed control method of this embodiment will be described below.

[0037] Figure 6 is a graph showing the change in the movement speed of the carriage 25 when the carriage 25 is moved in the +X direction in this embodiment. The carriage 25 moves at a constant speed once it accelerates from a stationary state to a predetermined movement speed, and maintains constant speed movement until it hits the abutment portion 203 provided at the end of the carriage 25 in the direction of movement, and stops when it hits the abutment portion 203. The movement speed of the carriage 25 when the detection unit 27 detects the reference side end 201 of the recording medium PM does not have to be the movement speed when recording. In this embodiment, the movement speed of the carriage 25 when the high-precision sensor 27b detects the reference side end 201 of the recording medium PM is set to 8 ips, which is slower than the movement speed when recording.

[0038] When the detection unit 27 detects the non-reference end 202 of the recording medium PM, the carriage 25 starts moving in the direction of the non-reference end 202 (-X direction) from a state where it is in contact with the abutment portion 203 on the reference end 201 side (see Figure 3), and accelerates to a speed of 8 ips. Once accelerated to a speed of 8 ips, it moves at a constant speed. The detection unit 27 detects the position of the non-reference end 202 when it passes the upper part of the non-reference end 202 in the +Z direction. Upon detecting the position of the non-reference end 202, the carriage 25 starts to decelerate and stops just before contacting the abutment portion 204, or after lightly contacting it. After detecting the position of the non-reference end 202, there is a distance to decelerate before reaching the abutment portion 204, so the carriage 25 moves while decelerating and stops almost simultaneously with contacting the abutment portion 204.

[0039] Next, when detecting the reference end 201 of the recording medium PM, the carriage 25 begins to move in the direction of the reference end 201 (+X direction) and accelerates to a speed of 8 ips. Once it accelerates to a speed of 8 ips, it moves at a constant speed. The detection unit 27 detects the position of the reference end 201 when it passes the upper part of the reference end 201 in the +Z direction. After detecting the position of the reference end 201, the carriage 25 abuts against the abutment part 203 and stops.

[0040] In this way, the detection unit 27 detects the positions of the reference end 201 and the non-reference end 202 of the recording medium PM, and obtains the width of the recording medium PM from the detection result.

[0041] As described above, in this embodiment, a detection unit 27 is provided on the non-reference side of the carriage 25, and the carriage 25 can be moved at a constant speed when the detection unit 27 detects the positions of the reference end 201 and the non-reference end 202 of the recording medium PM. As a result, it is possible to achieve both miniaturization of the device and high-precision end detection.

[0042] (modified version) Figure 7 shows a modified example of this embodiment. In this modified example, the detection unit 27 is provided on the reference side of the carriage 25. In this case, when detecting the reference end 201 of the recording medium PM, the carriage 25 starts moving in the direction of the reference side (+X direction) from a state where it is in contact with the abutment portion 204 on the non-reference end side as shown in Figure 7, and moves at a constant speed once it accelerates to a speed of 8 ips. Then, when the detection unit 27 passes the upper part of the reference end 201 in the +Z direction, it detects the position of the reference end 201. After detecting the position of the reference end 201, there is a distance to decelerate before reaching the abutment portion 203, so the carriage 25 moves while decelerating and stops almost simultaneously when it comes into contact with the abutment portion 203.

[0043] When detecting the non-reference end 202 of the recording medium PM, the carriage 25 starts moving in the direction of the non-reference end 202 (-X direction), and after accelerating to a speed of 8 ips, it moves at a constant speed. The detection unit 27 detects the position of the non-reference end 202 when it passes the upper part of the non-reference end 202 in the +Z direction. Immediately after detecting the position of the non-reference end 201, the carriage 25 moves to the abutment part 204 without decelerating, and stops when it hits the abutment part 204.

[0044] Thus, even in a configuration where the detection unit 27 is provided on the reference side of the carriage 25, it is possible to provide a technology for detecting the edge of the paper with high accuracy.

[0045] (Second embodiment) A second embodiment of the present invention will be described below with reference to the drawings. Since the basic configuration of this embodiment is the same as that of the first embodiment, only the characteristic configurations will be described below.

[0046] Figure 8(a) shows the carriage 25 in this embodiment. In this embodiment, a first sensor 27a, which is less accurate than the sensor 27b used in the first embodiment, is placed on the reference side of the carriage 25, and a second sensor 27b, which is the same high accuracy as in the first embodiment, is placed on the non-reference side. The first sensor 27a is a low-accuracy sensor with one light-emitting part and one light-receiving part, while the second sensor 27b is a high-accuracy differential sensor with one light-emitting part and multiple light-receiving parts. The first sensor 27a is speed-dependent, and its detection accuracy decreases as the carriage speed increases. The high-accuracy sensor 27b is less speed-dependent and can perform high-accuracy detection by detecting the edge of the paper while moving at a constant speed.

[0047] Figure 8(b) is a graph showing the detection results of the first sensor 27a for each carriage speed. Since the first sensor 27a is speed-dependent, the detection accuracy differs depending on the carriage speed. In the case of the first sensor 27a, a detection delay occurs with respect to the position of the edge of the recording medium that is to be detected, and when the carriage speed is high, the difference from the position to be detected becomes large. Therefore, as shown in Figure 8(b), in order to accurately detect the edge position with the first sensor 27a, it is preferable to perform a correction according to the carriage speed. Note that the second sensor 27b is a differential type, so there is almost no difference in detection accuracy due to carriage speed.

[0048] Figures 9 and 10 show the positional relationship between the carriage 25 and the detection unit 27 in this embodiment. Figure 9 shows the state in which the carriage 25 is in contact with the abutment portion 203 on the reference end 201 side of the recording medium PM, and Figure 10 shows the state in which the carriage 25 is in contact with the abutment portion 204 on the non-reference end 202 side of the recording medium PM.

[0049] In this embodiment, so-called micro-margin recording, as described in Patent Document 1, is performed. Specifically, in order to record images to the innermost edges of both ends of the recording medium, the detection unit 27 is used to detect the reference end 201 and the non-reference end 202 of the recording medium with each recording scan, and the start and end positions of the next recording scan are adjusted. In micro-margin recording, the first sensor 27a is used to detect the position of the reference end 201, and the second sensor 27b is used to detect the position of the non-reference end 202. The second sensor 27b is also used to detect the width of the recording medium before the recording operation. The edge detection by the second sensor 27b is the same as in the first embodiment, so the explanation is omitted.

[0050] When edge detection is performed in micro-margin recording, the carriage 25 has two movement speeds: the normal recording speed (40 ips in this embodiment) and a monitor control speed (20 ips) that is limited based on predetermined conditions, such as when the head temperature becomes high during recording.

[0051] When detecting the reference end 201, the carriage 25 starts moving toward the reference end 201 from a state where it is in contact with the abutment portion 204 on the non-reference end 202 side (Figure 10), and accelerates to a speed of 40 ips. Once it accelerates to a speed of 40 ips, it moves at a constant speed. The reference end 201 is detected when the first sensor 27a passes over the upper part of the reference end 201 in the +Z direction of the recording medium PM. On the other hand, when detecting the non-reference end 202, the carriage 25 starts moving toward the non-reference end 201 from a state where it is in contact with the abutment portion 203 on the reference end 202 side (Figure 9), and accelerates to a speed of 40 ips. Once it accelerates to a speed of 40 ips, it moves at a constant speed. The non-reference end 202 is detected when the second sensor 27b passes over the upper part of the non-reference end 202 in the +Z direction of the recording medium PM. As shown in Figure 10, with the carriage 25 in contact with the abutment portion 204 on the non-reference end 202 side of the recording medium PM, the first sensor 27a has not reached the non-reference end 202 of the recording medium PM. Therefore, the low-precision sensor 27a does not detect the non-reference end 202.

[0052] As mentioned above, the first sensor 27a is speed-dependent and therefore requires correction. In this embodiment, the position of the reference end 201 detected by the second sensor 27b is compared with the position of the reference end 201 detected by the first sensor 27a, and a correction value is obtained in advance to match the position of the second sensor 27b. Such correction values ​​are then determined for both the case where the carriage 25 moves at a speed of 40 ips and the case where it moves at a speed of 20 ips. When actually performing micro-margin recording, a correction is made to the position of the reference end 201 acquired by the first sensor 27a, according to the movement speed of the carriage 25, after each recording scan.

[0053] In this way, by correcting the position detection result of the reference end 201 by the first sensor 27a for carriage 25 movement speeds of 40 ips and 20 ips, it becomes possible to detect the recording medium end position with high accuracy even when using a low-precision sensor.

[0054] Figure 11 is a flowchart showing the process for performing micro-margin recording in the liquid dispensing device 1 of this embodiment. The series of processes shown in Figure 11 are performed by the MPU 31 of the liquid dispensing device 1 expanding the program code stored in the ROM of the storage device 32 into RAM and executing it. Alternatively, some or all of the functions of the steps in Figure 11 may be implemented in hardware such as an ASIC or electronic circuit. The symbol "S" in the description of each process means that it is a step in the flowchart. The recording process in this embodiment will be described below using the flowchart in Figure 11.

[0055] When the recording process for the micromargin is started by a recording command from the host computer 100, the MPU 31 starts feeding the recording medium PM in S1101. In S1102, the MPU 31 determines the carriage speed to be used for recording (40 ips) and the carriage speed to be reduced if the head temperature becomes high during the recording operation (carriage speed when monitor control is activated = 20 ips). In S1103, the MPU 31 scans the carriage 25 in the -X direction at the carriage speed to be used for recording, and detects the position of the non-reference end 202 by passing the upper part of the non-reference end 202 over the second sensor 27b and obtains the detection result. After the second sensor 27b has passed the non-reference end 202, the carriage 25 decelerates and stops almost simultaneously with contacting the abutment part 203.

[0056] In S1104, the MPU31 scans the carriage 25 in the +X direction at the carriage speed used for recording, and detects the position of the reference end 202 by passing the upper part of the reference end 201 over the second sensor 27b, thereby acquiring the detection result. At this time, the carriage 25 abuts against the abutment section 204 and stops without decelerating.

[0057] In S1105, the MPU31 determines the width (paper width) of the recording medium PM based on the positions of the reference end 201 detected in S1103 and the non-reference end 202 detected in S1102.

[0058] Next, in S1106, the MPU 31 moves the carriage 25 in the +X direction at the carriage speed normally used during recording (40 ips in this embodiment), detects the position of the reference end 201 using the first sensor 27a, and obtains the detection result.

[0059] Furthermore, in S1107, the MPU31 moves the carriage 25 in the +X direction at the carriage speed (20 ips), detects the position of the reference end 201 using the first sensor 27a, and obtains the detection result.

[0060] In S1108, the MPU31 determines the correction value for the first sensor 27a at the carriage speed during normal recording based on the detection result of the second sensor 27b at the reference end 201 (S1104) and the detection result of the first sensor 27a at the carriage speed during normal recording (S1106). In S1109, the MPU31 determines the correction value for the first sensor 27a at the carriage speed during monitor control based on the detection result of the second sensor 27b at the reference end 201 (S1104) and the detection result of the first sensor 27a at the carriage speed during monitor control (S1107).

[0061] In S1110, the MPU31 determines whether the next recording scan is a recording scan at normal speed. If it is a recording scan at normal speed, it proceeds to S1111; otherwise, it proceeds to S1112. If it is a recording scan at normal speed, the MPU31 sets the correction value determined in S1108 in S1111. If it is not a recording scan at normal speed, i.e., it is at monitor-controlled carriage speed, it sets the correction value determined in S1109.

[0062] In S1113, the MPU 31 performs a recording scan. During this scan, while causing the recording unit 26 to perform an ejection operation according to the recording data, the positions of the reference end 201 and the non-reference end 202 of the recording medium are acquired. For the position of the reference end 201, a correction is applied to the detection result of the first sensor 27a using a correction value set in S1111 or S1113. The positions of the reference end 201 and the non-reference end 202 acquired in this way are used to control the recording position of the image during the next recording scan. Once one recording scan is completed, in S1114, the MPU 31 determines whether or not another recording scan is necessary (i.e., whether or not there is still image data to be recorded). If another recording scan is necessary, the process proceeds to S1110 and is repeated. If another recording scan is not necessary, this recording process is terminated. On the other hand, if in S1114 it is determined that another recording scan is not necessary (i.e., the recording operation is complete), this process is terminated.

[0063] In this embodiment, as described above, a low-precision first sensor 27a is provided on the reference side of the carriage 25, and a high-precision second sensor 27b is provided on the non-reference side. While the carriage is moved at a constant speed, the second detection unit 27b detects the reference end 201, and the position of the reference end 201 detected by the first sensor 27b is corrected based on the position of the reference end 201 obtained in this way. Based on this correction, the scanning area in which liquid is discharged from the liquid discharge head is changed. This makes it possible to perform high-precision micro-margin recording while detecting the edge of the recording medium with high precision.

[0064] (Third embodiment) A third embodiment of the present invention will be described below with reference to the drawings. Since the basic configuration of this embodiment is the same as that of the first embodiment, only the characteristic configurations will be described below.

[0065] Figure 12 shows the carriage 25 and detection unit 27 in this embodiment. In this embodiment, a sensor 27a similar to the first sensor 27a used in the second embodiment is provided as the detection unit 27 on the non-reference side of the carriage 25. The sensor 27a is speed-dependent, and the detection accuracy decreases as the detection speed increases. In this embodiment, correction is performed by utilizing this characteristic of the sensor 27a. Specifically, the detection result performed by the sensor 27a at an extremely low speed is used to correct the detection performed by the sensor 27a at a high speed. The method is described below.

[0066] Figure 13 is a flowchart showing the recording process in the liquid dispensing device 1 of this embodiment. The series of processes shown in Figure 13 are performed by the MPU 31 of the liquid dispensing device 1 expanding the program code stored in the ROM of the storage device 32 into RAM and executing it. Alternatively, some or all of the functions of the steps in Figure 13 may be implemented in hardware such as an ASIC or electronic circuit. The symbol "S" in the description of each process means that it is a step in the flowchart. The recording process in this embodiment will be described below using the flowchart in Figure 13.

[0067] When the recording process for the micromargin is initiated by a recording command from the host computer 100, the MPU 31 starts feeding the recording medium PM in S1301. In S1302, the MPU 31 determines the carriage speed to be used for recording (40 ips) and the carriage speed to be reduced if the head temperature becomes high during the recording operation (carriage speed when monitor control is activated = 20 ips).

[0068] In S1303, the MPU31 scans the carriage 25 in the -X direction at an even slower speed than the monitor control (5 ips in this embodiment), and detects the position of the non-reference end 202 by passing the upper part of the non-reference end 202 over the sensor 27a, thereby obtaining the detection result. The speed in this case is such that, in micro-margin recording, the detection delay, as explained in Figure 8(b), is kept within an error that does not cause problems in the image. In S1304, the MPU31 scans the carriage 25 in the +X direction at an even slower speed than the monitor control (5 ips in this embodiment), and detects the position of the reference end 201 by passing the upper part of the reference end 201 over the sensor 27a, thereby obtaining the detection result. When detecting the reference end 201, the carriage 25 is stopped by abutting against the abutment part 203. In step S1305, the MPU31 determines the width (paper width) of the recording medium PM based on the positions of the reference end 201 and the non-reference end 202 detected at a low speed (5 ips).

[0069] In S1306, the MPU31 moves the carriage 25 in the +X direction at the carriage speed normally used during recording (40 ips in this embodiment), and uses the sensor 27a to detect the position of the reference end 201 and obtain the detection result. At this time, the carriage 25 stops when it comes into contact with the abutment portion 203.

[0070] Subsequently, in S1307, the MPU 31 moves the carriage 25 in the +X direction at the carriage speed (20 ips), detects the position of the reference end 201 using 27a, and obtains the detection result. The carriage 25 is stopped by abutting against the abutment part 203.

[0071] In S1308, the MPU31 determines the correction value for sensor 27a at the carriage speed during normal recording, based on the detection result acquired at the low carriage speed at the reference end 201 (S1304) and the detection result acquired at the carriage speed during normal recording (S1306). In S1309, the MPU31 determines the correction value for sensor 27a at the carriage speed during monitor control, based on the detection result acquired at the low carriage speed at the reference end 201 (S1304) and the detection result at the carriage speed during monitor control (S1307).

[0072] In S1310, the MPU31 determines whether the next recording scan is at normal speed. If it is at normal speed, the process proceeds to S1311; otherwise, it proceeds to S1312. If it is at normal speed, the MPU31 sets the correction value determined in S1308 in S1311. If it is not at normal speed, i.e., at monitor-controlled carriage speed, the MPU31 sets the correction value determined in S1309 in S1312.

[0073] In S1313, the MPU 31 performs a recording scan. During this scan, while causing the recording unit 26 to eject according to the recording data, the positions of the reference end 201 and the non-reference end 202 of the recording medium are acquired. The positions of these ends are corrected using the correction values ​​set in S1311 or S1313 based on the detection results of the sensor 27a. The positions of the reference end 201 and the non-reference end 202 acquired in this way are used to control the recording position of the image during the next recording scan. Once one recording scan is completed, in S1314, the MPU 31 determines whether or not another recording scan is necessary (i.e., whether or not there is still image data to be recorded). If another recording scan is necessary, the process proceeds to S1310 and is repeated. If another recording scan is not necessary, this recording process is terminated.

[0074] In this embodiment, as described above, a detection unit 27 equipped with a speed-dependent sensor 27a is provided on the non-reference side of the carriage 25. The carriage is moved at a low speed at which speed dependence is negligible, and the detection unit 27 detects the edge of the reference recording medium. Based on the edge position of the reference recording medium obtained in this way, the edge position of the recording medium at normal speed is corrected. This makes it possible to perform high-precision micro-margin recording while detecting the edge of the paper.

[0075] This embodiment includes the following configurations and methods.

[0076] (Composition 1) A conveying means for conveying the sheet in the conveying direction, A carriage equipped with a liquid dispensing head and capable of reciprocating in a scanning direction intersecting the transport direction, At the reference-side limit position of the carriage in the scanning direction, a first abutment portion that can come into contact with the carriage, A second abutment portion that can contact the carriage at the limit of movement on the non-reference side opposite to the reference side of the carriage in the scanning direction, A first detection means is provided at the non-reference end of the carriage and detects the end position of the recording medium while moving together with the carriage. A control means for controlling the movement of the carriage and the first detection means, A liquid dispensing device equipped with, The liquid dispensing device is characterized in that, when the first detection means detects the position of the reference end of the recording medium, it moves the carriage at a constant speed until the carriage abuts against the first abutment portion.

[0077] (Configuration 2) The liquid dispensing apparatus according to configuration 1, wherein the control means reduces the movement speed of the carriage after the first detection means detects the position of the non-reference end of the recording medium and before the carriage abuts against the second abutment portion.

[0078] (Composition 3) The liquid dispensing device according to configuration 2, wherein the control means stops the carriage after the first detection means detects the position of the non-reference end of the recording medium and before the carriage abuts against the second abutment portion.

[0079] (Composition 4) A liquid dispensing device according to any one of configurations 1 to 3, comprising a second detection means provided at the reference end of the carriage for detecting the end position of the recording medium while it is moving.

[0080] (Composition 5) The liquid dispensing device according to configuration 4, wherein the second detection means has a higher velocity dependence in the detection result compared to the first detection means, and further comprises a correction means for correcting the detection result of the second detection means based on the detection result of the first detection means.

[0081] (Composition 6) The liquid dispensing apparatus according to configuration 5, wherein the correction means corrects the end position on the reference side detected by the second detection means while moving the carriage from the non-reference side to the reference side, based on the end position on the reference side detected by the first detection means while moving the carriage from the non-reference side to the reference side.

[0082] (Composition 7) The liquid discharge device according to configuration 6, wherein the correction means corrects the detection result of the second detection means by a first correction value when the movement speed of the carriage at the time of detection by the second detection means is a first movement speed, and corrects the detection result of the second detection means by a second correction value different from the first correction value when the movement speed of the carriage at the time of detection by the second detection means is a second movement speed different from the first movement speed.

[0083] (Composition 8) The liquid dispensing device according to configuration 1, further comprising a correction means for correcting the detection result detected by the first detection means when the carriage is moving at a second movement speed that is faster than the first movement speed, based on the detection result detected by the first detection means when the carriage is moving at a first movement speed.

[0084] (Composition 9) The first moving speed is the moving speed of the carriage during the recording operation. The liquid dispensing device according to configuration 8, wherein the second travel speed is the travel speed of the carriage during recording operation, limited based on predetermined conditions.

[0085] (Composition 10) The liquid dispensing device according to configuration 4, wherein the first detection means and the second detection means are optical sensors.

[0086] (Composition 11) The liquid dispensing device according to configuration 10, wherein the first detection means is a differential sensor.

[0087] (Composition 12) The control means records an image on a recording medium by discharging liquid from the liquid discharge head while moving the carriage in the scanning direction. A liquid dispensing device according to Configuration 1, which changes the region in the scanning direction in which liquid is dispensed from the liquid dispensing head based on the edge position of the recording medium acquired by the first detection means.

[0088] (Method 1) A transport process for transporting the recording medium in the transport direction, A movement step in which the carriage is moved back and forth between a reference-side movement limit position and a non-reference-side movement limit position in a scanning direction intersecting the aforementioned transport direction, A first detection step involves detecting the edge position of the recording medium using a first detection means provided at the non-reference end of the carriage, An end detection method having, An edge detection method characterized in that, when detecting the position of the reference edge of the recording medium in the first detection step, the carriage is moved at a constant speed until it abuts against a stopper located at the limit of movement position on the reference side.

[0089] (Method 2) The end detection method according to method 1, wherein, after the first detection means detects the position of the non-reference end of the recording medium, the carriage's movement speed is reduced before it abuts against a stopper at the non-reference limit position.

[0090] (Method 3) The end detection method according to method 2, wherein after the first detection means detects the position of the non-reference end of the recording medium, the carriage is stopped before it abuts against a stopper at the movement limit position on the non-reference side.

[0091] (Method 4) An edge detection method according to any one of methods 1 to 3, which has a second detection step of detecting the edge position of a recording medium while moving it using a second detection means provided at the reference end of the carriage.

[0092] (Method 5) The end detection method according to method 4, further comprising a correction step of correcting the detection result of the second detection means, which has a higher speed dependence in the detection result compared to the first detection means, based on the detection result of the first detection means.

[0093] (Method 6) The end detection method according to method 5, wherein the correction step involves moving the carriage from the non-reference side to the reference side and correcting the end position on the reference side detected by the second detection means while moving the carriage from the non-reference side to the reference side, based on the end position on the reference side detected by the first detection means.

[0094] (Method 7) The end detection method according to method 6, wherein in the correction step, when the movement speed of the carriage at the time of detection by the second detection means is the first movement speed, the detection result of the second detection means is corrected by the first correction value, and when the movement speed of the carriage at the time of detection by the second detection means is a second movement speed different from the first movement speed, the detection result of the second detection means is corrected by a second correction value different from the first correction value.

[0095] (Method 8) The end detection method according to Method 1, further comprising a correction step of correcting the detection result detected by the first detection means when the carriage is moving at a second moving speed that is faster than the first moving speed, based on the detection result detected by the first detection means when the carriage is moving at a first moving speed. [Explanation of Symbols]

[0096] 1 Liquid discharge device 25 Carriage 26 Recording Unit 27 Detection Unit 27a Sensor 27b Sensor 31 MPU 201 Reference end 202 Non-reference end

Claims

1. A conveying means for conveying the sheet in the conveying direction, A carriage equipped with a liquid dispensing head and capable of reciprocating in a scanning direction intersecting the transport direction, At the reference side limit position of the carriage in the scanning direction, a first abutment portion that can come into contact with the carriage, A second abutment portion that can contact the carriage at the limit of movement on the non-reference side opposite to the reference side of the carriage in the scanning direction, A first detection means is provided at the non-reference end of the carriage and detects the end position of the recording medium while moving together with the carriage, A control means for controlling the movement of the carriage and the first detection means, A liquid dispensing device equipped with, The liquid dispensing device is characterized in that, when the first detection means detects the position of the reference end of the recording medium, it moves the carriage at a constant speed until the carriage abuts against the first abutment portion.

2. The liquid dispensing apparatus according to claim 1, wherein the control means reduces the movement speed of the carriage after the first detection means detects the position of the non-reference end of the recording medium and before the carriage abuts against the second abutment portion.

3. The liquid dispensing apparatus according to claim 2, wherein the control means stops the carriage after the first detection means detects the position of the non-reference end of the recording medium and before the carriage abuts against the second abutment portion.

4. The liquid dispensing device according to claim 1, further comprising a second detection means provided at the reference end of the carriage for detecting the end position of the recording medium while it is moving.

5. The liquid dispensing device according to claim 4, wherein the second detection means has a higher velocity dependence in the detection result compared to the first detection means, and further comprises a correction means for correcting the detection result of the second detection means based on the detection result of the first detection means.

6. The liquid dispensing apparatus according to claim 5, wherein the correction means corrects the end position on the reference side detected by the second detection means while moving the carriage from the non-reference side to the reference side, based on the end position on the reference side detected by the first detection means while moving the carriage from the non-reference side to the reference side.

7. The liquid dispensing apparatus according to claim 6, wherein the correction means corrects the detection result of the second detection means by a first correction value when the movement speed of the carriage at the time of detection by the second detection means is a first movement speed, and corrects the detection result of the second detection means by a second correction value different from the first correction value when the movement speed of the carriage at the time of detection by the second detection means is a second movement speed different from the first movement speed.

8. The liquid dispensing device according to claim 1, further comprising a correction means for correcting the detection result detected by the first detection means when the carriage is moving at a second movement speed that is faster than the first movement speed, based on the detection result detected by the first detection means when the carriage is moving at a first movement speed.

9. The first movement speed is the movement speed of the carriage during the recording operation. The liquid dispensing device according to claim 8, wherein the second moving speed is the moving speed of the carriage during recording operation, limited based on predetermined conditions.

10. The liquid dispensing device according to claim 4, wherein the first detection means and the second detection means are optical sensors.

11. The liquid dispensing device according to claim 10, wherein the first detection means is a differential sensor.

12. The control means records an image on a recording medium by discharging liquid from the liquid discharge head while moving the carriage in the scanning direction. The liquid dispensing device according to claim 1, wherein the region in the scanning direction in which liquid is dispensed from the liquid dispensing head is changed based on the edge position of the recording medium acquired by the first detection means.

13. A transport process for transporting the recording medium in the transport direction, A movement step in which the carriage is moved back and forth between a reference-side movement limit position and a non-reference-side movement limit position in a scanning direction intersecting the aforementioned transport direction, A first detection step involves detecting the edge position of the recording medium using a first detection means provided at the non-reference end of the carriage, An end detection method having, An edge detection method characterized in that, when detecting the position of the reference end of the recording medium in the first detection step, the carriage is moved at a constant speed until it abuts against a stopper located at the limit of movement position on the reference side.

14. The end detection method according to claim 13, wherein, after the first detection means detects the position of the non-reference end of the recording medium, the carriage's movement speed is reduced before the carriage abuts against a stopper at the non-reference limit position.

15. The end detection method according to claim 14, wherein after the first detection means detects the position of the non-reference end of the recording medium, the carriage is stopped before it abuts against a stopper at the limit of movement position on the non-reference side.

16. The edge detection method according to claim 13, further comprising a second detection step of detecting the edge position of a recording medium while moving it using a second detection means provided at the reference end of the carriage.

17. The end detection method according to claim 16, further comprising a correction step of correcting the detection result of the second detection means, which has a higher speed dependence in the detection result compared to the first detection means, based on the detection result of the first detection means.

18. The end detection method according to claim 17, wherein in the correction step, the carriage is moved from the non-reference side to the reference side, and the end position of the reference side detected by the second detection means is corrected based on the end position of the reference side detected by the first detection means while the carriage is moved from the non-reference side to the reference side.

19. The end detection method according to claim 18, wherein in the correction step, when the movement speed of the carriage at the time of detection by the second detection means is the first movement speed, the detection result of the second detection means is corrected by the first correction value, and when the movement speed of the carriage at the time of detection by the second detection means is a second movement speed different from the first movement speed, the detection result of the second detection means is corrected by a second correction value different from the first correction value.

20. The end detection method according to claim 13, further comprising a correction step of correcting the detection result detected by the first detection means when the carriage is moving at a second movement speed that is faster than the first movement speed, based on the detection result detected by the first detection means when the carriage is moving at a first movement speed.

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