Indirect transfer printer and indirect transfer film conveyance method

Abstract

This indirection transfer film conveying method: determines, during an initialization operation, that an indirect transfer film has not been exchanged before power on, when a transferred sensor mark is detected in a step in which the indirect transfer film is conveyed from a supply spool to a winding spool; estimates the unused amount of the indirect transfer film on the basis of the ratio between the rotation angle of the supply spool and the rotation angle of the winding spool; controls to position a primary transfer on the basis of a final sensor mark among sensor marks when the unused amount is estimated to be at least 2% that is a residual amount warning threshold or less; and determines that the unused amount is greater than the amount required for subsequent recording in a recording medium, when an end mark is not detected while the indirect transfer film is conveyed by the amount of prescribed screens from the final sensor mark, when the unused amount is estimated to be less than 2%.

Description

Technical Field

[0001] The present invention relates to an indirect transfer printer and an indirect transfer film conveyance method, and more particularly, to an indirect transfer printer and an indirect transfer film conveyance method that can omit wasteful film conveyance to improve issuance processing efficiency and suppress film conveyance deviation.

Background Art

[0002] An indirect transfer type printer is a printer that first transfers the ink layer of an ink ribbon unwound from a winding body of the ink ribbon to an indirect transfer film at a primary transfer portion using a thermal head, and then secondarily transfers it to a transfer target at a secondary transfer portion. In this type of indirect transfer method, even when the base material of the transfer target finally provided with an image is different such as paper or plastic, printing is performed on the indirect transfer film during primary transfer, so the printing target is constant and stable image formation is possible. Therefore, it has been put into practical use and utilized for various transfer targets.

[0003] On the other hand, the indirect transfer film of the indirect transfer printer is repeatedly reciprocated in the printer when initializing to detect an unused portion during primary transfer, when detecting the transfer start position of each color ink (also referred to as "position detection" or "head detection"), or when conveying the indirect transfer film for secondary transfer to the transfer target. At this time, winding deviation or winding wrinkles are likely to occur due to conveyance deviation or the like. In order to prevent winding deviation and winding wrinkles, very high assembly accuracy is required for the printer. As a result, the manufacturing difficulty of the printer is very high, which is also one of the causes of cost increase.

[0004] As a method for preventing winding deviation during film conveyance, in the conveyance of a photosensitive film for photography, as shown in FIG. 6, a method of providing regular perforations 201 in the film 200 and conveying it by a sprocket 202 has been used for a long time. Examples of applying such a method to a thermal transfer printer include Patent Document 1.

[0005] However, from the viewpoints of speeding up the indirect transfer printer and improving the printing sensitivity, the base materials used for ink ribbons, indirect transfer films, etc. are required to be as thin as possible, and actually need to be about several μm to several tens of μm. Therefore, in the method of providing the perforated portion 201 in the base material and conveying it with the sprocket 202, it has been difficult to adopt because breakage and wrinkles of the base material occur.

[0006] Therefore, in the conventional indirect transfer printer, an initialization operation as illustrated in FIG. 7 is performed.

[0007] In FIG. 7, 1 is a supply spool for the indirect transfer film 100, 4 is a take-up spool for the indirect transfer film 100, 52 is a platen roller in the primary transfer section, and 91 is a heat roller in the secondary transfer section.

[0008] FIG. 7(a) shows a state when the power of the indirect transfer printer with the indirect transfer film 100 in use is turned on and the initialization operation starts. On the indirect transfer film 100 in use, sensor marks m0, m1, m2,... serving as positioning marks when transferring an image from the ink ribbon in the primary transfer section are provided for each screen by printing or the like during manufacturing. Also, on the used screens, marks c0, c1, c2, c3, c4 indicating that they are used are recorded during the primary transfer.

[0009] When entering the initialization operation, as shown in FIG. 7(b), the indirect transfer film 100 is moved in the forward direction, and after the sensor sn1 detects the sensor mark m4 of the screen where the last mark c4 is recorded, it is further pulled out by 4.5 to 5 screens, and after confirming whether there is enough indirect transfer film 100 remaining for the next recording, it is necessary to rewind the indirect transfer film 100 and perform the head start for the primary transfer.

[0010] In the initialization operation of the printer as described above, in order to check the length of the unused portion of the indirect transfer film, an operation of reciprocatingly conveying the indirect transfer film over a long length is performed. Therefore, the indirect transfer film is likely to experience winding displacement and winding wrinkles, and during that time, the printer cannot actually be used. Therefore, it is required to shorten this operation to suppress the occurrence of winding displacement and winding wrinkles and to improve the working efficiency.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Summary of the Invention

[0012] Therefore, an object of the present invention is to provide an indirect transfer printer and an indirect transfer film conveyance method that can reduce the conveyance amount of the indirect transfer film itself, which causes conveyance deviation, thereby making it difficult for conveyance deviation to occur, shortening the initialization operation, and improving the working efficiency.

[0013] One aspect of the present invention for solving the above problems is that an indirect transfer printer includes a primary transfer unit that indirectly transfers an image from an ink ribbon to an indirect transfer film, a secondary transfer unit that secondarily transfers the image from the indirect transfer film to a recording medium, a sensor for primary transfer alignment, and a processor. The initialization operation of the indirect transfer printer sequentially includes a step of detecting, by the sensor for primary transfer alignment, a sensor mark transferred together with an image during a past primary transfer while the indirect transfer film is being conveyed from a supply spool to a take-up spool; a step of determining by the processor that the indirect transfer film has not been replaced before the initialization operation by detecting the transferred sensor mark; a step of estimating, by the processor, the remaining amount of the indirect transfer film based on the ratio of the rotation angles of the supply spool and the take-up spool measured by a rotary encoder from the start to the end of conveyance when it is determined that the indirect transfer film has not been replaced; a step of performing primary transfer positioning based on the last sensor mark among the sensor marks when it is estimated that the unused amount is equal to or greater than a remaining amount warning threshold; a step of conveying the indirect transfer film by an amount corresponding to the number of screens to be printed (two screens for double-sided printing, one screen for single-sided printing) and an error margin for one take-up rotation (equal to or greater than 0.5 screen and equal to or less than 2.5 screens) as a lead from the last sensor mark when it is estimated that the unused amount is less than the remaining amount warning threshold; and a step of determining by the processor that the unused amount is greater than the amount required for recording on the next recording medium when an end mark indicating the end of the usable area of the indirect transfer film is not detected by the sensor for primary transfer alignment during the conveying step.

[0014] In particular, when the sensor mark transferred together with the image during the past primary transfer is not detected while the indirect transfer film is being conveyed from the supply spool to the take-up spool by an amount corresponding to a predetermined number of screens, the processor can also determine that the indirect transfer film was replaced before the power was turned on.

[0015] Further, the indirect transfer printer further includes a first sensor that detects a sensor mark transferred together with an image during a past primary transfer, and the sensor for primary transfer alignment detects the last sensor mark.

[0016] Another aspect of the present invention for solving the above problems is a method of conveying an indirect transfer film during an initialization operation performed when power is turned on in an indirect transfer printer that primarily transfers an image from an ink ribbon to the indirect transfer film and secondarily transfers the image from the indirect transfer film to a recording medium. In this conveying method, when a sensor mark transferred together with an image during a past primary transfer is detected while the indirect transfer film is being conveyed from a supply spool to a take-up spool for a predetermined screen portion, it is determined that the indirect transfer film has not been replaced before power-on. Then, when it is determined that the indirect transfer film has not been replaced, while estimating the unused amount of the indirect transfer film based on the ratio between the rotation angle of the supply spool and the rotation angle of the take-up spool during the conveying process, if the unused amount is estimated to be 2% or more, which is the remaining amount warning threshold, the position of the primary transfer is determined based on the last sensor mark among the sensor marks, and if the unused amount is estimated to be less than 2%, which is the remaining amount warning threshold, when an end mark indicating the final end of the usable area of the indirect transfer film is not detected while the indirect transfer film is being conveyed for three screen portions as a lead from the last sensor mark, it is determined that the unused amount is more than the amount required for recording on the next recording medium.

[0017] Note that the remaining amount warning threshold is a threshold for the unused amount that needs to be unwound and confirmed. The remaining amount warning threshold can be set in the range of 1% or more and 5% or less. In particular, the remaining amount warning threshold is preferably 2%. The remaining amount warning threshold can be set according to the length of the conveyance path and the thickness of the indirect transfer film. The screen as a lead can be 0.5 screen or more and 4.5 screens. Also, it is preferable to set the screen portion of this lead to be longer than the length of the path until transfer. When the unused amount is equal to or more than the remaining amount warning threshold, the screen portion of the lead can be 0.5 screen from the second sensor (for primary transfer alignment). When the unused amount is equal to or more than the remaining amount warning threshold, the screen portion of the lead can be the total of the printed screen portion (two screens for double-sided, one screen for single-sided) and the winding rotation error margin portion from the second sensor (for primary transfer alignment). This winding rotation error margin portion can be more than 0.5 screen and 2.5 screens or less.

[0018] According to the present invention, even in the case of an indirect transfer film without a sensor mark used at the time of primary transfer in the manufacturing stage, at the time of initialization operation performed prior to starting printing when the indirect transfer printer is powered on, even if the amount of the indirect transfer film pulled out is small, it is possible to confirm the presence or absence of the sensor mark. When the sensor mark is detected, it is determined that the indirect transfer film has not been replaced before power-on, and if the unused amount is 2% or more of the remaining amount warning threshold value, it is also possible to omit transporting the indirect transfer film for detecting the end mark which is the last sensor mark. Therefore, it becomes possible to reduce the risk of occurrence of defects due to film misalignment. On the other hand, when the unused amount of the indirect transfer film is less than 2% which is the remaining amount warning threshold value, it is possible to confirm whether it is more than the amount necessary for recording the next recording medium.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below. Also, in the embodiments shown below, technically preferable limitations are made to implement the invention, but this limitation is not an essential requirement of the present invention.

[0021] FIG. 1 is a functional block diagram showing one aspect of the indirect transfer printer of the present invention.

[0022] As shown in FIG. 1, the indirect transfer printer 20 of the present invention includes a control board (processor) 21, a primary transfer unit 50, a secondary transfer unit 90, a first sensor (for secondary transfer alignment) SN1, and a second sensor (for primary transfer alignment) SN2. The control board (processor) 21 has an arithmetic circuit including a processing chip and a control chip, a memory such as a volatile memory and a non-volatile memory, an IO interface, and a bus mounted on a printed circuit board.

[0023] The first sensor (for secondary transfer alignment) SN1 can be a photoelectric sensor. The second sensor (for primary transfer alignment) SN2 can be a photoelectric sensor. The photoelectric sensor can be a transmissive type. The photoelectric sensor may be a reflective type. The photoelectric sensor may be integrated with a light source. The light source for the photoelectric sensor can be an LED. The light source for the photoelectric sensor can be a laser diode. The photoelectric sensor may include a photodiode.

[0024] FIG. 2 is a schematic configuration diagram showing one aspect of the indirect transfer printer of the present invention.

[0025] In the indirect transfer printer 20, the intermediate transfer medium 60 wound in a roll is unwound from the unwinding roll 70, passes through the primary transfer unit 50 and the secondary transfer unit 90, and is wound onto the winding roll 80. On the other hand, the thermal transfer medium 11 wound in a roll is unwound from the unwinding roll 30, passes through the primary transfer unit 50, and is wound onto the winding roll 40.

[0026] In the primary transfer unit 50, the transfer layer of the intermediate transfer medium 60 and the thermal transfer ink layer of the thermal transfer medium 11 are sandwiched between the thermal head 51 and the platen roller 52 so as to face each other. The thermal head 51 and the platen roller 52 are separated when the intermediate transfer medium 60 and the thermal transfer medium 11 are simply conveyed, and are pressed against each other when transfer recording from the thermal transfer medium 11 to the intermediate transfer medium 60 is performed, and predetermined image information is transferred to the transfer layer of the intermediate transfer medium 60.

[0027] Subsequently, in the secondary transfer unit 90, the transfer layer of the intermediate transfer medium 60 and the recording medium 120 are arranged so as to face each other, and the intermediate transfer medium 60 is thermocompression-bonded to the recording medium 120 pressed by the platen roller 92 by the heat roller 91 heated by the heater H, whereby the transfer layer of the intermediate transfer medium 60 is transferred to the recording medium 120 together with the image recorded in the primary transfer unit 50.

[0028] The recording medium 120 is stored in a stack (not shown), and is conveyed from this stack to the secondary transfer unit 90 by a conveying device.

[0029] The control board (processor) 21 can control the operations of the supply spool 1, the take-up spool 4, the primary transfer unit 50, the secondary transfer unit 90, and the conveying device based on the outputs from sensors such as the sensors SN1 and SN2.

[0030] FIG. 3 is an explanatory diagram showing a conveyance state when the remaining amount of the indirect transfer film, which is one aspect of the intermediate transfer medium, is 2% or more, which is the remaining amount warning threshold value.

[0031] As illustrated in FIG. 3, the indirect transfer film 10, which is one aspect of the intermediate transfer medium 60, is conveyed from the supply spool 1 to the take-up spool 4.

[0032] The supply spool 1 is provided with an indirect transfer film 10 wound in a roll shape. The supply spool 1 includes a shaft (not shown) that rotatably supports the roll composed of the indirect transfer film 10. The supply spool 1 may further include a brake for adjusting the tension applied to the unwound thermal transfer medium 11.

[0033] The take-up spool 4 winds up the indirect transfer film 10 unwound from the supply spool 1. The take-up spool 4 is provided with a motor (not shown) for winding.

[0034] The take-up spool 4 is provided with an indirect transfer film 10 wound in a roll shape. The indirect transfer film 10 can include a base material and an overlay layer provided on one main surface thereof. The indirect transfer film 10 may not include an overlay layer. The take-up spool 4 includes a shaft (not shown) that rotatably supports the roll composed of the indirect transfer film 10 and a motor (not shown) that rotates the shaft forward / backward. The take-up spool 4 enables the unwinding and rewinding of the indirect transfer film 10.

[0035] The indirect transfer printer 20 includes a primary transfer unit 50 and a secondary transfer unit 90 in the conveyance path of the indirect transfer film 10 from the supply spool 1 to the take-up spool 4. Further, the primary transfer unit 50 includes a thermal head 51 and a platen roller 52, and the secondary transfer unit 90 includes a heat roller 91 and a platen roller 92.

[0036] As described with reference to FIG. 2, in the primary transfer unit 50, an image is primarily transferred from the thermal transfer medium 11 to the intermediate transfer medium 60, and in the secondary transfer unit 90, the image is secondarily transferred from the intermediate transfer medium 60 to the recording medium 120. Therefore, when the intermediate transfer medium 60 is the indirect transfer film 10 shown in FIG. 3, in the primary transfer unit 50, the thermal head 51 and the platen roller 52 are arranged to face each other with the thermal transfer medium 11 and the intermediate transfer medium 60 therebetween. The thermal head 51 applies a thermal pressure to the thermal transfer medium 11 to cause the transfer of ink from the thermal transfer medium 11 to the intermediate transfer medium 60. The intensity of the laser light transmitted through the thermal transfer medium 11 or reflected by the thermal transfer medium 11 is detected by a light sensor (not shown). The output of this light sensor can be used for alignment of the thermal transfer medium 11 with respect to the thermal head 51 and the like.

[0037] In the secondary transfer unit 90, the heat roller 91 and the platen roller 92 are arranged to face each other with the intermediate transfer medium 60 sent out from the primary transfer unit 50 and the recording medium 120 therebetween. The heat roller 91 applies a thermal pressure to the intermediate transfer medium 60 to cause the transfer of the ink layer from the intermediate transfer medium 60 to the recording medium 120. When the intermediate transfer medium 60 includes an overlay layer, the heat roller 91 applies a thermal pressure to the intermediate transfer medium 60 to transfer the laminate of the ink layer and the overlay layer from the intermediate transfer medium 60 to the recording medium 120.

[0038] Although not shown in FIG. 2, a first sensor (for secondary transfer alignment) SN1 for detecting the position of the intermediate transfer medium 60 during secondary transfer is arranged near the heat roller 91 of the secondary transfer unit 90. Also, a second sensor (for primary transfer alignment) SN2 for detecting the position of the intermediate transfer medium 60 during primary transfer is arranged near the platen roller 52 of the primary transfer unit 50.

[0039] Furthermore, the indirect transfer printer 20 also has a control unit (not shown) for controlling each part of the indirect transfer printer 20 and for data processing and control of image information and sensor information. Note that for the first sensor (for secondary transfer alignment) SN1 and the second sensor (for primary transfer alignment) SN2, in the illustrated arrangement, the first sensor (for secondary transfer alignment) SN1 is provided at a position approximately 1.5 screens away from the standard standby position of the last sensor mark after the printer operation is completed. However, in addition to the illustrated arrangement, the positions of the first sensor (for secondary transfer alignment) SN1 and the second sensor (for primary transfer alignment) SN2 may be set according to the arrangements of the primary transfer unit 50 and the secondary transfer unit 90, the size of the screen to be recorded, etc. The standard standby position of the last sensor mark after the printer operation is completed for the indirect transfer type printer will be described later.

[0040] The intermediate transfer medium 60 has a function of being conveyed in the forward direction from the unwinding roll 70 toward the winding roll 80 for color overlay during primary transfer and for alignment in the primary transfer unit 50 and the secondary transfer unit 90, and also has a function of being conveyed in the reverse direction. That is, it is possible to perform reciprocating conveyance in the forward and reverse directions. In addition, motors (not shown) for forward and reverse rotation driving can be connected to the unwinding roll 70 and the winding roll 80. The motor can be a stepping motor. Also, an AC motor or a DC motor may be used. Other known motors can also be connected. The motor may be directly connected to the unwinding roll 70 and the winding roll 80, or may be connected via a gear. The motor may also be electrically driven by a motor driver. The motor driver may be an inverter.

[0041] As described by referring back to FIG. 3, usually, the sensor marks on the indirect transfer film 10 are only the head mark, which is a sensor mark for optically detecting the head of the usable area in the unused state where all the ink ribbons have not been transferred, and the end mark, which is a sensor mark for detecting the end of the usable area. In other words, no other sensor marks are provided in between.

[0042] On one hand, on the indirect transfer film 10 during the transfer process, sensor marks serving as alignment marks when transferring an image from the ink ribbon at the primary transfer unit 50 are recorded for each screen. The image is transferred to the recording medium 120 together with the transfer layer etc. at the secondary transfer unit 90, but since the sensor marks are not transferred, only the sensor marks remain in the used area of the indirect transfer film 10. Fig. 3(a) shows the state when entering the initialization operation with the indirect transfer film 10 being used in such a way mounted. The initialization operation can be an operation before starting the transfer. The initialization operation is performed when the power is turned on, when resuming from the standby state, when resuming from the sleep state, etc.

[0043] At this time, on the indirect transfer film 10, sensor marks M are left on the used screens as M0, M1, M2, M3, M4 ···. Each sensor mark M is formed at a predetermined part that is either at the front end part or the rear end part in the forward direction of each screen and does not overlap with the image to be secondarily transferred. In this embodiment, an example where the sensor mark M is formed at the rear end part is shown.

[0044] In the initialization operation, first, as shown in Fig. 3(b), while pulling out and conveying the indirect transfer film 10 by a predetermined number of screens in the forward direction, the sensor mark M is detected by the first sensor (for secondary transfer alignment) SN1. With the arrangement of the heat roller 91 of the secondary transfer unit 90 and the sensor SN1, it can be determined by pulling out two screens. In addition, depending on the arrangement of the heat roller 91 of the secondary transfer unit 90 and the first sensor (for secondary transfer alignment) SN1, particularly depending on the span of these arrangements, different numbers of screens can be set in advance. As a result, the sensor marks M0 and M1 will be detected. When the first sensor (for secondary transfer alignment) SN1 detects the sensor mark M, the control board (processor) 21 determines that the indirect transfer film 10 has not been replaced since the previous printer operation.

[0045] At this time, the control board (processor) 21 simultaneously detects the rotation speed of the supply spool 1 and the rotation angle of the take-up spool 4, and estimates the amount of the unused indirect transfer film 10 remaining on the supply spool 1 from the ratio thereof. While the amount of the used indirect transfer film 10 is small, since the diameter of the indirect transfer film 10 on the supply spool 1 side is large and the diameter on the take-up spool 4 side is small, the rotation angle of the supply spool 1 when transporting a predetermined length of the indirect transfer film 10 is smaller than the rotation angle of the take-up spool 4. As the use of the indirect transfer film 10 progresses, since the diameter of the indirect transfer film 10 on the supply spool 1 side gradually decreases, the rotation angle of the supply spool 1 gradually increases. When it is used until near the end of the indirect transfer film 10, the diameter of the indirect transfer film 10 on the take-up spool 4 side increases. For this reason, the rotation angle of the supply spool 1 further increases, and conversely, the rotation angle of the take-up spool 4 further decreases. Therefore, by detecting the rotation speed of the supply spool 1 and the rotation angle of the take-up spool 4 and obtaining the ratio thereof, the amount of the unused indirect transfer film 10 remaining on the supply spool 1 can be estimated. Detection of the rotation angle of the spool can be appropriately performed by adopting a known rotary encoder or the like. The rotary encoder can be of an incremental type or an absolute type. This detection of the rotation angle can be performed, for example, from the ratio of the rotation angle of the take-up spool and the rotation angle of the supply spool during the movement when transporting one screen.

[0046] When it is determined that the remaining amount of the unused indirect transfer film 10 on the estimated supply spool 1 is 2% or more, which is the remaining amount warning threshold of the spool in the initial unused state, even considering the estimation error, it is considered that there is still enough indirect transfer film 10 remaining to perform at least the primary transfer and secondary transfer on the next screen. Therefore, the control board (processor) 21 omits the unwinding of the indirect transfer film 10 to check the remaining amount of the indirect transfer film 10, and in order to perform the head start of the primary transfer, as shown in Fig. 3(c), the indirect transfer film 10 is conveyed until the last sensor mark M0 reaches the second sensor (for primary transfer alignment) SN2, and the control is performed to perform the head start. In the head start operation, the sensor mark M0 is moved to a position where the unused area of the indirect transfer film 10 is not affected by the residual heat emitted from the heat roller 91. The position not affected by the residual heat emitted from the heat roller 91 is, for example, near the outlet of the supply spool 1.

[0047] Generally, since the indirect transfer film 10 is often wound so that it can process around 300 to 500 recording media 120 in one roll, 2% of it corresponds to 6 to 10 sheets. Even if there is an estimation error, it can be determined that there is still enough indirect transfer film 10 remaining unused.

[0048] Then, as shown in Fig. 4(d), on the next screen P of the sensor mark M0, the primary transfer of the image is performed, and a new sensor mark Mx is transferred to the end of the screen P. After that, as shown in Fig. 4(e), the indirect transfer film 10 is conveyed to the secondary transfer unit 90 side for secondary transfer, and is transferred to the recording medium 120 by the heat roller 91. At this time, the first sensor (for secondary transfer alignment) SN1 can also be used for the head start of the secondary transfer alignment.

[0049] After the secondary transfer is completed, the control board (processor) 21 stops the indirect transfer film 10 at a position where the sensor mark Mx, which has become the last sensor mark, is on the supply spool 1 side of the first sensor (for secondary transfer alignment) SN1 and the heat roller 91. By doing so, it is possible to prevent the unused portion of the indirect transfer film 10 from being damaged by the heat generated from the heat roller 91. Also, the sensor mark Mx will be used as the last sensor mark when transferring the next screen.

[0050] Therefore, if the use of the indirect transfer printer 20 is terminated in this state, and the indirect transfer film 10 is not replaced by the time the next printer is used, this position will become the standard standby position for the indirect transfer film 10 and the like at the start of the next initialization operation. For this reason, if the control board (processor) 21 transports the indirect transfer film 10 forward by two screens when using the printer next time, it can detect the sensor mark Mx and determine that the indirect transfer film 10 has not been replaced.

[0051] As described above, in the indirect transfer printer 20 of the present invention, since it is not necessary to print sensor marks for each screen in advance on the indirect transfer film 10 during manufacturing, the manufacturing process for printing sensor marks is unnecessary, and it is also advantageous in terms of cost.

[0052] In addition, when it is determined that the indirect transfer film 10 has been replaced after the previous printer operation, the processing can be different because the arrangement of the indirect transfer film 10 is different from the standard arrangement as described above. For example, it is conceivable to transport the indirect transfer film 10 in the reverse direction to wind it back and detect the leading mark or the sensor mark that has been wound up, but it is not particularly limited.

[0053] When the control board (processor) 21 determines that the estimated amount of the unused indirect transfer film 10 is less than 2% of the remaining amount warning threshold of the initial amount of the indirect transfer film 10, considering the estimation error, there may not be a sufficient amount of the indirect transfer film 10 remaining. Therefore, the control board (processor) 21 withdraws the actual remaining indirect transfer film 10 by the amount required for recording and checks the remaining amount as follows.

[0054] FIGS. 4(a) and (b) show the states when entering the initialization operation, similar to the above-described case. As described above, the control board (processor) 21 estimates the amount of the unused indirect transfer film 10 remaining on the supply spool 1 based on the ratio of the rotation speed of the supply spool 1 to the rotation angle of the take-up spool 4. When it is determined that the estimated amount of the unused indirect transfer film 10 is less than 2% of the initial amount, the control board (processor) 21 controls to further withdraw the indirect transfer film 10 by three screens as shown in FIG. 4(c) and check whether the amount of the indirect transfer film 10 actually used remains. The three screens are considered in consideration of the front surface, back surface, and one screen as a margin of the recording medium 120.

[0055] When the control board (processor) 21 confirms that there is a remaining amount of three screens, it controls to convey in the reverse direction until the sensor mark M0 reaches the second sensor (for primary transfer alignment) SN2 as shown in FIG. 4(d) and perform the head start for primary transfer. Then, as shown in FIG. 4(e), the primary transfer of the image is performed on the next screen P of the sensor mark M0, and a new sensor mark Mx is transferred to the end of the screen P. The subsequent operations are the same as those in the above-described case and are omitted. In the head start operation, the sensor mark M0 is moved to a position where the unused area of the indirect transfer film 10 is not affected by the residual heat emitted by the heat roller 91. The position not affected by the residual heat emitted by the heat roller 91 is, for example, near the outlet of the supply spool 1.

[0056] When the remaining amount of the indirect transfer film 10 has decreased to about less than 2%, it becomes difficult for winding deviation and winding wrinkles to occur. Moreover, even if winding deviation or winding wrinkles occur, the influence is limited. Therefore, even if the film pulling operation as described above is performed, the substantial influence is small.

[0057] As described above, when the remaining amount of the indirect transfer film 10 at the time of initialization is 2% or more, since the pulling out and rewinding of the indirect transfer film 10 for confirming the remaining amount of the indirect transfer film 10 can be omitted, winding deviation and winding wrinkles that are likely to occur during conveyance by the heat roller 91 of the secondary transfer unit 90 and the platen roller 52 of the primary transfer unit 50 can be suppressed. At the same time, the time required for pulling out and rewinding the indirect transfer film 10 can also be saved. Further, when the remaining amount is less than 2%, the necessary amount of the indirect transfer film 10 is unwound and confirmed, so the indirect transfer film 10 will not run out during recording.

[0058] FIG. 5 is a flowchart showing an example of an initialization operation in the indirect transfer printer of the present invention.

[0059] First, steps S0 to S7, which are the main initialization operations, will be described.

[0060] In the main initialization operation, when the power of the indirect transfer printer 20 is turned on, the initialization operation is started (S0), and the indirect transfer film 10 is conveyed for two screens (S1).

[0061] Accordingly, when the sensor mark M is detected by the first sensor (for secondary transfer alignment) SN1 (S2: Yes), the process proceeds to step S3, and when it is not detected (S2: No), the process proceeds to step S13.

[0062] In step S3, the control board (processor) 21 determines that the indirect transfer film 10 has not been replaced before power-on (S3). Thereafter, the control board (processor) 21 estimates the amount of the unused indirect transfer film 10 remaining on the supply spool 1 from the ratio between the rotation angle of the supply spool 1 and the rotation angle of the take-up spool 4 (S4).

[0063] As a result of this estimation, if the amount of the unused indirect transfer film 10 is 2% or more, which is the remaining amount warning threshold (S4: Yes), the process proceeds to step S5; if it is less than 2% which is the remaining amount warning threshold (S4: No), the process proceeds to step S8.

[0064] In step S5, the control board (processor) 21 controls to convey the indirect transfer film 10 to the primary transfer start position (S5). Thereafter, when the last sensor mark M of the indirect transfer film 10 is detected by the second sensor (for primary transfer alignment) SN2 (S6: Yes), the control board (processor) 21 performs control for alignment at the primary transfer start position, and the transfer by the primary transfer unit 50 is started (S7).

[0065] Next, steps S8 to S10, which are the operations when it is determined that the remaining film amount is less than 2%, will be described.

[0066] In step S8, the control board (processor) 21 controls to pull out the indirect transfer film 10 for three screens (S8). In response to this, when an end mark is detected by the second sensor (for primary transfer alignment) SN2 (S9: Yes), the control board (processor) 21 determines that the indirect transfer film 10 has been all used up, and the operation ends (S10).

[0067] On the other hand, if the end mark is not detected in step S9 (S9: No), the process proceeds to step S5.

[0068] Next, steps S11 to S12, which are the operations of the process when an error occurs in the second sensor (for primary transfer alignment) SN2, will be described.

[0069] In step S11, it is determined by the control board (processor) 21 that an error has occurred in the second sensor (for primary transfer alignment) SN2 (S11), and the operation ends (S12).

[0070] Finally, steps S13 to S16, which are the operations when the indirect transfer film 10 was replaced before power-on, will be described.

[0071] In step S13, it is determined by the control board (processor) 21 that the indirect transfer film 10 was replaced before power-on (S13). Thereafter, it is controlled by the control board (processor) 21 to rewind the indirect transfer film 10. As a result, when the head mark or sensor mark indicating the leading end of the usable area of the indirect transfer film 10 is detected by the second sensor (for primary transfer alignment) SN2 (S14: Yes), the process proceeds to step S5.

[0072] On the other hand, in step S14, when the head mark or sensor mark indicating the leading end of the usable area of the indirect transfer film 10 is not detected by the second sensor (for primary transfer alignment) SN2 (S14: No), it is determined by the control board (processor) 21 that there is an error in the second sensor (for primary transfer alignment) SN2 (S15), and the operation ends (S16).

[0073] As described above, according to the present invention, even for the indirect transfer film 10 without the sensor mark used at the time of primary transfer in the manufacturing stage, at the time of power-on of the indirect transfer printer 20, in the initialization operation performed prior to the start of printing, the presence or absence of the sensor mark M can be confirmed even if the amount of the indirect transfer film 10 pulled out is small. And when the sensor mark M is detected, it is determined that the indirect transfer film 10 has not been replaced before power-on, and if the unused amount is equal to or more than the remaining amount warning threshold (for example, 2%), the conveyance of the indirect transfer film 10 for detecting the end mark, which is the last sensor mark, can also be omitted, so that it is possible to reduce the risk of occurrence of defects due to film misalignment. On the other hand, when the unused amount of the indirect transfer film 10 is less than the remaining amount warning threshold (for example, 2%), it is possible to confirm whether it is more than the amount necessary for recording the next recording medium 120.

[0074] Note that the present invention of the present application is not limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof at the implementation stage. Also, each embodiment may be implemented in an appropriate combination as much as possible, and in that case, the combined effects can be obtained. Further, the above-described embodiment includes inventions at various stages, and various inventions can be extracted by appropriate combinations of a plurality of disclosed constituent elements.

Explanation of Reference Numerals

[0075] 1 ··· Supply spool, 4 ··· Take-up spool, 10 ··· Indirect transfer film, 11 ··· Thermal transfer medium, 20 ··· Indirect transfer printer, 21 ··· Control board (processor), 30 ··· Pay-out roll, 40 ··· Take-up roll, 50 ··· Primary transfer unit, 51 ··· Thermal head, 52 ··· Platen roller, 60 ··· Intermediate transfer medium, 70 ··· Pay-out roll, 80 ··· Take-up roll, 90 ··· Secondary transfer unit, 91 ··· Heat roller, 92 ··· Platen roller, 100 ··· Indirect transfer film, 120 ··· Recording medium, 200 ··· Film, 201 ··· Perforation part, 202 ··· Sprocket, SN1 ··· First sensor (for secondary transfer alignment), SN2 ··· Second sensor (for primary transfer alignment), sn1 ··· First sensor (for secondary transfer alignment), sn2 ··· Second sensor (for primary transfer alignment), c (c0, c1, c2, c3, c4) ··· Mark, H ··· Heater, M (M0, M1, M2, M3, M4) ··· Sensor mark, m (m0, m1, m2, m3, m4, m5, m6, m7, m8, m9) ··· Sensor mark

Claims

1. An indirect transfer printer includes a primary transfer unit that primarily transfers an image from an ink ribbon to an indirect transfer film, a secondary transfer unit that secondarily transfers the image from the indirect transfer film to a recording medium, a sensor for primary transfer alignment, and a processor, wherein the initialization operation of the indirect transfer printer sequentially includes a step of detecting, by the sensor for primary transfer alignment, a sensor mark transferred together with an image during a past primary transfer while the indirect transfer film is being conveyed from a supply spool to a take-up spool; a step of determining by the processor that the indirect transfer film has not been replaced before the initialization operation by detecting the transferred sensor mark; a step of estimating, by the processor, the remaining amount of the indirect transfer film based on the ratio of the rotation angles of the supply spool and the take-up spool measured by a rotary encoder from the start to the end of the conveyance when it is determined that the indirect transfer film has not been replaced; a step of performing alignment of the primary transfer based on the last sensor mark among the sensor marks when it is estimated that the unused amount is equal to or greater than a remaining amount warning threshold; a step of conveying the indirect transfer film by an amount corresponding to a screen portion as a lead and an error margin of one take-up rotation from the last sensor mark when it is estimated that the unused amount is less than the remaining amount warning threshold; a step of determining by the processor that the unused amount is greater than the amount required for recording on the next recording medium when an end mark indicating the final end of the usable area of the indirect transfer film is not detected by the sensor for primary transfer alignment during the conveying step. An indirect transfer printer, characterized by the above.

2. The processor is characterized in that when no sensor mark transferred together with an image during a past primary transfer is detected while the indirect transfer film is being conveyed from the supply spool to the take-up spool by an amount corresponding to a predetermined screen portion, it determines that the indirect transfer film has been replaced before power-on. The indirect transfer printer according to Claim 1.

3. The indirect transfer printer according to Claim 1 or 2, further comprising a first sensor for detecting a sensor mark transferred together with an image during the past primary transfer, wherein the sensor for primary transfer alignment detects the last sensor mark.

4. The indirect transfer printer according to claim 2, characterized in that the predetermined screen portion is two screens.

5. A method of transporting the indirect transfer film during an initialization operation performed when the power of an indirect transfer printer is turned on, the method including: primary-transferring an image from an ink ribbon to the indirect transfer film, and secondary-transferring the image from the indirect transfer film to a recording medium. When a sensor mark transferred together with an image during a previous primary transfer is detected while the indirect transfer film is being transported from a supply spool to a take-up spool by a predetermined screen portion, a step of determining that the indirect transfer film has not been replaced before the power is turned on. When it is determined that the indirect transfer film has not been replaced, a step of estimating the unused amount of the indirect transfer film based on the ratio between the rotation angle of the supply spool and the rotation angle of the take-up spool during the transportation process. When it is estimated that the unused amount is 2% or more of the remaining amount warning threshold, a step of determining the position of the primary transfer based on the last sensor mark among the sensor marks. When it is estimated that the unused amount is less than 2% of the remaining amount warning threshold, a step of determining that the unused amount is more than the amount required for recording on the next recording medium if an end mark indicating the final end of the usable area of the indirect transfer film is not detected while the indirect transfer film is being transported for three screens as a lead from the last sensor mark.

Images