JP2007269497A - Printing device, printing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing device and a printed body lower end deciding method for obtaining a position of a lower end of a printed body with high precision and to provide a computer program and a computer system. <P>SOLUTION: This printing device is provided with a feeding means for feeding the supplied printed body in a predetermined direction of feeding, a light emitting means for emitting light, and a light receiving sensor for receiving the light emitted by the light emitting means to detect change of an output value of the light receiving sensor by shielding the light emitted by the light emitting means by the printed body fed by the feeding means. This printing device detects change of the output value by shielding light by the lower end of the printed body at a plurality of positions to obtain a position in the direction of feeding of either of a left end and a right end at the lower end which is fed late in the direction of feeding based on the results of detection. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing apparatus, a printing medium lower end determination method, a computer program, and a computer system.

  A color inkjet printer, which is a typical printing apparatus, is already well known. This color ink jet printer includes an ink jet print head that ejects ink from nozzles, and is configured to record images, characters, and the like by landing ink droplets on printing paper as an example of a printing medium. Yes.

The print head is supported by a carriage, which is an example of a movable member that includes the print head in a state where the nozzle surface on which the nozzles are formed is opposed to the print paper, and is moved along the guide member. The ink is ejected in synchronization with the main scanning.
In recent years, color ink jet printers capable of so-called borderless printing, which performs printing on the entire surface of printing paper, are gaining popularity for the reason that an output result of the same image as a photograph can be obtained. By borderless printing, for example, it is possible to print by ejecting ink without margins on the four edges of the printing paper.

  By the way, in order to perform printing accurately at a position where dots should be formed on the printing paper, it is necessary to accurately grasp the position of the printing paper. As a procedure for realizing this, the printing apparatus grasps the position of the lower end of the printing paper.

  Several methods have been proposed for grasping the position of the lower end of the printing paper, but a light receiving sensor (e.g., a photodiode that emits light from a light emitting diode, etc., and the printing paper being fed blocks the light) Hereinafter, there is a method of grasping the position of the lower end by detecting a change in the output value of the light receiving unit).

  However, since the printing paper may be bent (obliquely) fed (or fed), the position of the lower end grasped by such a method is strictly behind in the paper feeding direction. There is a possibility that a problem may arise in terms of the accuracy of grasping the lower end position of the printing apparatus, not the position to be sent.

  In particular, in case of borderless printing, since printing is also performed on the bottom edge of the printing paper, it is necessary to accurately grasp the position of the bottom edge of the printing paper. There is a possibility that a problem such as a blank area is formed at the bottom of the printing paper. In order to avoid such a problem, if printing is performed with an enlarged print area and a margin, a problem such as consumption of extra ink may occur.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a printing apparatus, a printing medium lower end determination method, a computer program, and a computer that accurately grasp the position of the lower end of the printing medium. To realize the system.

  The main present invention comprises a feeding means for feeding a supplied printing medium in a predetermined feeding direction, a light emitting means for emitting light, a light receiving sensor for receiving light emitted by the light emitting means, A printing apparatus that detects a change in an output value of the light receiving sensor due to the printing medium sent by the feeding means blocking light emitted by the light emitting means. Change in the output value due to the lower end of the light blocking the light, and based on the detection result, one of the left end and the right end of the lower end that is sent later in the feed direction. A printing apparatus characterized by obtaining a position.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to implement | achieve the printing apparatus which grasps | ascertains the position of the lower end of a to-be-printed body accurately, the to-be-printed body lower end determination method, a computer program, and a computer system.

=== Summary of disclosure ===
At least the following will be made clear by the description of the present specification and the accompanying drawings.

  A feeding means for feeding the supplied printing material in a predetermined feeding direction; a light emitting means for emitting light; and a light receiving sensor for receiving the light emitted by the light emitting means; In the printing apparatus that detects a change in the output value of the light receiving sensor due to the printing medium sent by the means blocking the light emitted by the light emitting means, the lower end of the printing medium is the light at a plurality of positions. Detecting a change in the output value due to blocking, and obtaining a position in the feed direction of one of the left end and the right end of the lower end that are sent later in the feed direction based on the detection result. Characteristic printing device.

  Changes in the output value due to the lower end of the printing medium blocking the light at a plurality of positions are detected, and based on the detection result, the lower end of the lower end and the right end are sent behind in the feeding direction. By obtaining the position in one of the feeding directions, the position of the lower end of the printing medium can be grasped with high accuracy.

Moreover, it is good also as ejecting ink from a printing head and forming a dot in the said to-be-printed body.
In a so-called ink jet type printing apparatus that performs printing by discharging ink from a print head, the quality of the printing result is particularly required, so that the merit of the above-described means is further increased.

The light emitting means and the light receiving sensor may be moved in the main scanning direction to detect a change in the output value due to the lower end of the printing medium blocking the light at a plurality of positions.
In this way, the number of light emitting means and light receiving sensors prepared can be reduced.

Further, a change in the output value due to the lower end of the printing medium blocking the light at a first position and a second position that are different from each other in the main scanning direction is detected. A position in the main scanning direction of the second position, and a feed amount of the printing medium from when the change in the output value is detected at the first position until the change in the output value is detected at the second position; Based on the above, the position of one of the left end and the right end of the lower end that is sent later in the feed direction may be obtained.
In this way, the number of times the change in the output value of the light receiving sensor is detected can be minimized, and the procedure can be simplified.

Further, it is determined before moving the light emitting means and the light receiving sensor from the first position which of the left end and the right end of the lower end is sent later in the feeding direction, and based on the determined result, It may be determined whether the second position is set on the downstream side in the main scanning direction as viewed from the first position or on the upstream side.
In this way, it is possible to avoid the inefficiency of passing the temporary position when moving from the first position to the second position.

  Further, the output value of the light receiving sensor is obtained by stopping the printing medium and moving the light emitting means in the main scanning direction so that the light emitted by the light emitting means blocks the edge of the printing medium. Detecting the change of the position, specifying the position of the end, and determining which of the left end and the right end of the lower end is sent later in the feed direction based on the specified position of the end. Also good.

  The operation of stopping the printing medium and moving the light emitting means in the main scanning direction is the same as the operation for printing on the printing medium, so that the determination can be performed efficiently. Information can be obtained.

Further, after the position of the edge is specified, the printing medium is fed by the feeding means, the printing medium is stopped, and the light emitting means is moved in the main scanning direction to be emitted by the light emitting means. The light detection sensor detects the change in the output value of the light receiving sensor due to the light blocking the edge of the printing medium, identifies the edge position, and determines the lower edge based on the identified two edge positions. It may be determined which of the left end and the right end is sent later in the feed direction.
In this case, since more information for the determination is made, it can be accurately determined which of the left end and the right end of the lower end is sent later in the feed direction.

The light emitting means and the light receiving sensor may be provided on a movable member that includes a print head for forming dots and is movable.
If it does in this way, the moving mechanism of the said moving member, the said light emission part, and the said light-receiving part can be made shared.

Moreover, it is good also as printing for the whole surface of the said to-be-printed body.
When printing on the entire surface of the printing medium, since printing is also performed on the lower edge of the printing medium, it is necessary to accurately grasp the position of the lower edge of the printing medium. Becomes larger.

A feeding unit for feeding the supplied printing medium in a predetermined feeding direction; a light emitting unit for emitting light; and a light receiving sensor for receiving the light emitted by the light emitting unit; Detecting a change in the output value of the light receiving sensor due to the printing medium sent by the feeding means blocking the light emitted by the light emitting means, ejecting ink from a print head to detect all of the printing medium. In a printing apparatus that performs printing on a surface, the light emitting unit and the light receiving sensor are provided on a movable member that includes a print head for ejecting ink to form dots, and the light emitting unit. The output by moving the light receiving sensor in the main scanning direction so that the lower end of the printing medium blocks the light at different first and second positions in the main scanning direction. Change in the main scanning direction of the first position, the position of the second position in the main scanning direction, and the change in the output value at the first position after the change in the output value is detected at the second position. Based on the feed amount of the printing medium until the change of the output value is detected, one of the left end and the right end of the lower end is determined to be fed later in the feeding direction, and the printing target is obtained. The body is stationary and the light emitting means is moved in the main scanning direction to detect a change in the output value of the light receiving sensor due to the light emitted by the light emitting means blocking the edge of the printed body. The position of the edge is specified, and after the position of the edge is specified, the printing medium is fed by the feeding means, the printing medium is stopped, and the light emitting means is moved in the main scanning direction. And the light emitted by the light emitting means Detects the change in the output value of the light receiving sensor due to blocking the edge of the substrate to be printed, identifies the position of the edge, and based on the identified two edge positions, It is determined before moving the light emitting means and the light receiving sensor from the first position which of the right ends is sent later in the feeding direction, and based on the determined result, the second position is A printing apparatus that determines whether to set to the downstream side in the main scanning direction as viewed from the first position or to set to the upstream side.
In this way, the effects of the present invention can be achieved most effectively because all the effects described above can be achieved.

A feeding unit for feeding the supplied printing medium in a predetermined feeding direction; a light emitting unit for emitting light; and a light receiving sensor for receiving the light emitted by the light emitting unit; In a printing medium lower end determination method by a printing apparatus that detects a change in an output value of the light receiving sensor due to the printing medium sent by the feeding means blocking light emitted by the light emitting means, at a plurality of positions. A step of detecting a change in the output value due to the lower end of the printing medium blocking the light, and one of the left end and the right end of the lower end being sent later in the feeding direction based on the detection result A step of determining a position in the feeding direction of the printing medium.
Changes in the output value due to the lower end of the printing medium blocking the light at a plurality of positions are detected, and based on the detection result, the lower end of the lower end and the right end are sent behind in the feeding direction. By obtaining the position in one of the feeding directions, the position of the lower end of the printing medium can be grasped with high accuracy.

  It is also possible to realize a computer program for causing a printing apparatus to execute the above method that achieves the above-described effect that the position of the lower end of the printing medium can be accurately grasped.

Also, a computer main body, a display device connectable to the computer main body, and a printing device connectable to the computer main body, and sending means for sending the supplied printing medium in a predetermined feeding direction, and emitting light A light emitting means for receiving the light emitted by the light emitting means, and the printing medium sent by the sending means blocks the light emitted by the light emitting means. A printing apparatus that detects a change in an output value of the light receiving sensor, and detects a change in the output value due to a lower end of the printing medium blocking the light at a plurality of positions, and based on the detection result A computer system, comprising: a printing device that obtains a position in the feed direction of either one of the left end and the right end of the lower end that is fed later in the feed direction. Beam.
The computer system realized in this way is a system superior to the conventional system as a whole system.

=== Example of Overall Configuration of Apparatus ===
FIG. 1 is a block diagram showing a configuration of a printing system as an example of the present invention. This printing system includes a computer 90 and a color inkjet printer 20 as an example of a printing apparatus. The printing system including the color inkjet printer 20 and the computer 90 can also be called a “printing apparatus” in a broad sense. Although not shown, from the computer 90, the color inkjet printer 20, a display device such as a CRT 21 or a liquid crystal display device, an input device such as a keyboard or a mouse, a drive device such as a flexible drive device or a CD-ROM drive device, or the like. A computer system has been built.

  In the computer 90, an application program 95 operates under a predetermined operating system. A video driver 91 and a printer driver 96 are incorporated in the operating system, and print data PD to be transferred to the color inkjet printer 20 is output from the application program 95 via these drivers. The application program 95 that performs image retouching or the like performs desired processing on the image to be processed, and displays an image on the CRT 21 via the video driver 91.

  When the application program 95 issues a print command, the printer driver 96 of the computer 90 receives the image data from the application program 95 and converts it into print data PD to be supplied to the color inkjet printer 20. The printer driver 96 includes a resolution conversion module 97, a color conversion module 98, a halftone module 99, a rasterizer 100, a user interface display module 101, a UI printer interface module 102, and a color conversion lookup table LUT. And are provided.

  The resolution conversion module 97 plays a role of converting the resolution of the color image data formed by the application program 95 into the print resolution. The image data thus converted in resolution is still image information composed of three color components of RGB. The color conversion module 98 converts RGB image data into multi-gradation data of a plurality of ink colors that can be used by the color inkjet printer 20 for each pixel while referring to the color conversion lookup table LUT.

  The color-converted multi-gradation data has, for example, 256 gradation values. The halftone module 99 performs so-called halftone processing to generate halftone image data. The halftone image data is rearranged in the order of data to be transferred to the color inkjet printer 20 by the rasterizer 100, and is output as final print data PD. The print data PD includes raster data indicating the dot formation state during each main scan and data indicating the sub-scan feed amount.

  The user interface display module 101 has a function of displaying various user interface windows related to printing, and a function of receiving user input in these windows.

  The UI printer interface module 102 has a function of interfacing between a user interface (UI) and a color inkjet printer. Interpret the command instructed by the user through the user interface and send various commands COM to the color inkjet printer, or conversely interpret the command COM received from the color inkjet printer and perform various displays on the user interface .

  The printer driver 96 realizes a function of transmitting / receiving various commands COM, a function of supplying print data PD to the color inkjet printer 20, and the like. A program for realizing the function of the printer driver 96 is supplied in a form recorded on a computer-readable recording medium. Such recording media include flexible disks, CD-ROMs, magneto-optical disks, IC cards, ROM cartridges, punch cards, printed matter on which codes such as bar codes are printed, computer internal storage devices (such as RAM and ROM). A variety of computer-readable media such as a memory) and an external storage device can be used. It is also possible to download such a computer program to the computer 90 via the Internet.

  FIG. 2 is a schematic perspective view illustrating an example of a main configuration of the color inkjet printer 20. The color inkjet printer 20 includes a paper stacker 22, a paper feed roller 24 driven by a step motor (not shown), a platen 26, and a carriage as an example of a movable moving member that includes a print head for forming dots. 28, a carriage motor 30, a traction belt 32 driven by the carriage motor 30, and a guide rail 34 for the carriage 28. In addition, a print head 36 having a large number of nozzles and a reflective optical sensor 29 described in detail later are mounted on the carriage 28.

  The printing paper P is taken up from the paper stacker 22 by a paper feeding roller 24 and fed on the surface of the platen 26 in a paper feeding direction (hereinafter also referred to as a sub-scanning direction) as an example of the feeding direction of the printing medium. The carriage 28 is pulled by a pulling belt 32 driven by a carriage motor 30 and moves in the main scanning direction along the guide rail 34. The main scanning direction means two directions perpendicular to the sub-scanning direction as shown in the figure. The paper feeding roller 24 also performs a paper feeding operation for supplying the printing paper P to the color ink jet printer 20 and a paper discharging operation for discharging the printing paper P from the color ink jet printer 20.

=== Configuration Example of Reflective Optical Sensor ===
FIG. 3 is a schematic diagram for explaining an example of the reflective optical sensor 29. The reflective optical sensor 29 is attached to the carriage 28, and includes a light emitting unit 38 as an example of a light emitting unit including, for example, a light emitting diode, and a light receiving unit 40 as an example of a light receiving sensor including, for example, a phototransistor. . Light emitted from the light emitting unit 38, that is, incident light, is reflected by the platen 26 when the printing paper P is not in the direction of the printing paper P or emitted light, and the reflected light is received by the light receiving unit 40, and is electrically Converted to a signal. And the magnitude | size of an electrical signal is measured as an output value of the light receiving sensor according to the intensity of the received reflected light.

  In the above description, as shown in the drawing, the light emitting unit 38 and the light receiving unit 40 are integrated to form a device called the reflective optical sensor 29. However, like the light emitting device and the light receiving device, respectively. A separate device may be configured.

  In the above, in order to obtain the intensity of the received reflected light, the magnitude of the electric signal is measured after converting the reflected light into an electric signal. However, the present invention is not limited to this. It is only necessary to measure the output value of the light receiving sensor according to the intensity of the reflected light.

=== Example of configuration around carriage ===
Next, the configuration around the carriage will be described. FIG. 4 is a diagram showing a configuration around the carriage 28 of the inkjet printer.

  The ink jet printer shown in FIG. 4 has a paper feed motor (hereinafter also referred to as a PF motor) 31 that feeds paper as an example of a printing medium feed means, and a print head 36 that ejects ink onto the printing paper P. A carriage 28 driven in the main scanning direction, a carriage motor (hereinafter also referred to as a CR motor) 30 for driving the carriage 28, a linear encoder 11 fixed to the carriage 28, and slits are formed at predetermined intervals. The linear encoder code plate 12, the rotary encoder 13 (not shown) for the PF motor 31, the platen 26 that supports the printing paper P, and the paper feed roller that is driven by the PF motor 31 to transport the printing paper P 24, a pulley 25 attached to the rotating shaft of the CR motor 30, and a traction belt driven by the pulley 25 And a 2.

  Next, the linear encoder 11 and the rotary encoder 13 will be described. FIG. 5 is an explanatory diagram schematically showing the configuration of the linear encoder 11 attached to the carriage 28.

  The linear encoder 11 shown in FIG. 5 includes a light emitting diode 11a, a collimator lens 11b, and a detection processing unit 11c. The detection processing unit 11c includes a plurality of (for example, four) photodiodes 11d, a signal processing circuit 11e, and, for example, two comparators 11fA and 11fB.

  When the voltage VCC is applied to both ends of the light emitting diode 11a through a resistor, light is emitted from the light emitting diode 11a. This light is condensed into parallel light by the collimator lens 11 b and passes through the linear encoder code plate 12. The linear encoder code plate 12 is provided with slits at predetermined intervals (for example, 1/180 inch (1 inch = 2.54 cm)).

  The parallel light that has passed through the linear encoder code plate 12 passes through a fixed slit (not shown), enters each photodiode 11d, and is converted into an electrical signal. The electric signals output from the four photodiodes 11d are processed in the signal processing circuit 11e, the signals output from the signal processing circuit 11e are compared in the comparators 11fA and 11fB, and the comparison result is output as a pulse. The pulses ENC-A and ENC-B output from the comparators 11fA and 11fB are the outputs of the linear encoder 11.

  FIG. 6 is a timing chart showing waveforms of two output signals of the linear encoder 11 at the time of forward rotation and reverse rotation of the CR motor.

  As shown in FIGS. 6 (a) and 6 (b), the pulse ENC-A and the pulse ENC-B differ in phase by 90 degrees in both cases of CR motor forward rotation and reverse rotation. When the CR motor 30 is rotating forward, that is, when the carriage 28 is moving in the main scanning direction, the pulse ENC-A is 90 degrees from the pulse ENC-B, as shown in FIG. When the phase is advanced by the time and the CR motor 30 is reversely rotated, the phase of the pulse ENC-A is delayed by 90 degrees from the pulse ENC-B, as shown in FIG. One cycle T of the pulse ENC-A and the pulse ENC-B is equal to the time during which the carriage 28 moves through the slit interval of the linear encoder code plate 12.

  Then, the rising edge and the rising edge of each of the output pulses ENC-A and ENC-B of the linear encoder 11 are detected, the number of detected edges is counted, and the rotational position of the CR motor 30 is based on the counted value. Is calculated. This count is incremented by “+1” when one edge is detected when the CR motor 30 is rotating forward, and is “−1” when one edge is detected when the CR motor 30 is rotating in the reverse direction. Is added. The period of each of the pulses ENC-A and ENC-B is the time from when a slit passes through the linear encoder 11 until the next slit passes through the linear encoder 11 of the linear encoder code plate 12. The pulse ENC-A and the pulse ENC-B are different in phase by 90 degrees. For this reason, the count value “1” of the count corresponds to ¼ of the slit interval of the linear encoder code plate 12. Thus, if the count value is multiplied by ¼ of the slit interval, the movement amount of the CR motor 30 from the rotational position corresponding to the count value “0” can be obtained based on the multiplication value. At this time, the resolution of the linear encoder 11 is ¼ of the slit interval of the linear encoder code plate 12.

  On the other hand, the rotary encoder 13 for the PF motor 31 has the same configuration as the linear encoder 11 except that the rotary encoder code plate 14 is a rotating disk that rotates in accordance with the rotation of the PF motor 31. Two output pulses ENC-A and ENC-B are output, and the movement amount of the PF motor 31 can be obtained based on the outputs.

=== Example of an electrical configuration of a color inkjet printer ===
FIG. 7 is a block diagram illustrating an example of an electrical configuration of the color inkjet printer 20. The color inkjet printer 20 includes a buffer memory 50 that receives a signal supplied from a computer 90, an image buffer 52 that stores print data, a system controller 54 that controls the overall operation of the color inkjet printer 20, and a main memory 56. And an EEPROM 58. The system controller 54 further includes a main scanning drive circuit 61 that drives the carriage motor 30, a sub-scanning drive circuit 62 that drives the paper feed motor 31, a head drive circuit 63 that drives the print head 36, and reflective optics. A reflection type optical sensor control circuit 65 that controls the light emitting unit 38 and the light receiving unit 40 of the sensor 29, the linear encoder 11 described above, and the rotary encoder 13 described above are connected. The reflection type optical sensor control circuit 65 includes an electric signal measurement unit 66 for measuring an electric signal converted from the reflected light received by the light receiving unit 40.

  The print data transferred from the computer 90 is temporarily stored in the buffer memory 50. In the color ink jet printer 20, the system controller 54 reads necessary information from the print data from the buffer memory 50, and based on this information, the system controller 54 sends it to the main scanning drive circuit 61, the sub-scanning drive circuit 62, the head drive circuit 63 and the like. Send a control signal to it.

  The image buffer 52 stores print data of a plurality of color components received by the buffer memory 50. The head drive circuit 63 reads the print data of each color component from the image buffer 52 in accordance with a control signal from the system controller 54 and drives the nozzle array of each color provided in the print head 36 in response to this.

=== Example of print head nozzle arrangement ===
FIG. 8 is an explanatory diagram showing the nozzle arrangement on the lower surface of the print head 36. The print head 36 has a black nozzle row and a color nozzle row arranged on a straight line along the sub-scanning direction. In this specification, the “nozzle row” is also referred to as “nozzle group”.

  The black nozzle row (indicated by white circles) has 180 nozzles # 1 to # 180. These nozzles # 1 to # 180 are arranged at a constant nozzle pitch k · D along the sub-scanning direction. Here, D is the dot pitch in the sub-scanning direction, and k is an integer. The dot pitch D in the sub-scanning direction is equal to the pitch of the main scanning line (raster line). Hereinafter, the integer k representing the nozzle pitch k · D is simply referred to as “nozzle pitch k”. The unit of the nozzle pitch k is “dot”, which means the dot pitch in the sub-scanning direction.

  In the example of FIG. 8, the nozzle pitch k is 4 dots. However, the nozzle pitch k can be set to an arbitrary integer.

  The color nozzle array includes a yellow nozzle group Y (indicated by white triangles), a magenta nozzle group M (indicated by white squares), and a cyan nozzle group C (indicated by white rhombuses). In this specification, the nozzle group for chromatic ink is also referred to as a “chromatic nozzle group”. Each chromatic nozzle group has 60 nozzles # 1 to # 60. Further, the nozzle pitch of the chromatic nozzle group is the same as the nozzle pitch k of the black nozzle row. The nozzles of the chromatic color nozzle group are arranged at the same sub-scanning position as the nozzles of the black nozzle row.

  During printing, ink droplets are ejected from each nozzle while the print head 36 is moving in the main scanning direction together with the carriage 28. However, depending on the printing method, not all nozzles are always used, and only some nozzles may be used.

=== First Embodiment ===
Next, the first embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a diagram schematically showing the positional relationship among the print head 36, the reflective optical sensor 29, and the printing paper P, and FIG. 10 is a flowchart for explaining the first embodiment.

  First, the user instructs to perform printing in the application program 95 or the like (step S2). When the application program 95 that has received this instruction issues a print command, the printer driver 96 of the computer 90 receives image data from the application program 95 and receives the raster data and the sub data indicating the dot formation state during each main scan. The print data PD including the data indicating the scanning feed amount is converted. Further, the printer driver 96 supplies the print data PD to the color inkjet printer 20 together with various commands COM. The color inkjet printer 20 receives these by the buffer memory 50 and then transmits them to the image buffer 52 or the system controller 54.

  Further, the user can instruct the user interface display module 101 to perform the size of the printing paper P or borderless printing. The instruction by the user is received by the user interface display module 101 and sent to the UI printer interface module 102. The UI printer interface module 102 interprets the instructed command and transmits a command COM to the color inkjet printer 20. The color inkjet printer 20 receives the command COM by the buffer memory 50 and then transmits it to the system controller 54.

  Based on the command transmitted to the system controller 54, the color inkjet printer 20 feeds the printing paper P by driving the paper feed motor 31 by the sub-scanning drive circuit 62 (step S4).

  Then, the system controller 54 moves the carriage 28 in the main scanning direction while feeding the printing paper P in the paper feeding direction, and discharges ink from the print head 36 provided in the carriage 28 to perform borderless printing ( Step S6, Step S8). The printing paper P is fed in the paper feeding direction by driving the paper feeding motor 31 by the sub-scanning driving circuit 62, and the carriage 28 is moved in the main scanning direction by the main scanning driving circuit 61. The ink is ejected from the print head 36 by being driven by driving the print head 36 by the head drive circuit 63.

  The color inkjet printer 20 continues to perform the operations of step S6 and step S8. For example, when the number of movements of the carriage 28 in the main scanning direction reaches a predetermined number (step S10), the next main scanning direction. From the movement of the carriage 28 to the center, the following operation is performed.

  The system controller 54 controls the reflective optical sensor 29 provided in the carriage 28 by the reflective optical sensor control circuit 65, and emits light from the light emitting unit 38 of the reflective optical sensor 29 toward the platen 26 (step). S12).

  Next, as shown in FIGS. 9A and 9B, the system controller 54 drives the CR motor 30 to move the carriage 28. Eventually, as shown in FIG. 9B, the light emitted from the light emitting unit 38 blocks the end of the printing paper P (step S14). At this time, the incident destination of the light emitted from the light emitting unit 38 is changed from the platen 26 to the printing paper P, so that the electric signal that is the output value of the light receiving unit 40 of the reflective optical sensor 29 that has received the reflected light. The size changes. Then, the magnitude of this electric signal is measured by the electric signal measuring unit 66, and it is detected that the edge of the printing paper P has passed the light.

  Then, the movement amount from the reference position of the CR motor 30 is obtained based on the output pulse of the linear encoder 11, and the movement amount, in other words, the position of the carriage 28 (hereinafter also referred to as position X1) is stored (step). S16).

  Then, as shown in FIGS. 9B and 9C, the system controller 54 drives the CR motor 30 to further move the carriage 28 in the main scanning direction to perform printing on the printing paper P ( Step S18).

  Next, as shown in FIGS. 9C and 9D, the system controller 54 drives the CR motor 30 to move the carriage 28 and also drives the paper feed motor 31 to perform printing. The paper P is fed by a predetermined amount (step S20).

  Next, the color inkjet printer 20 repeats the operations from step S14 to step S20 described above.

  That is, as shown in FIGS. 9D and 9E, the system controller 54 drives the CR motor 30 to move the carriage 28. Eventually, as shown in FIG. 9 (e), the light emitted from the light emitting section 38 blocks the end of the printing paper P (step S14). At this time, the incident destination of the light emitted from the light emitting unit 38 is changed from the platen 26 to the printing paper P, so that the electric signal that is the output value of the light receiving unit 40 of the reflective optical sensor 29 that has received the reflected light. The size changes. Then, the magnitude of this electric signal is measured by the electric signal measuring unit 66, and it is detected that the edge of the printing paper P has passed the light.

  Then, the movement amount from the reference position of the CR motor 30 is obtained based on the output pulse of the linear encoder 11, and the movement amount, in other words, the position of the carriage 28 (hereinafter also referred to as position X2) is stored (step). S16).

  Then, as shown in FIGS. 9E and 9F, the system controller 54 drives the CR motor 30 to further move the carriage 28 in the main scanning direction to perform printing on the printing paper P ( Step S18).

  Next, the system controller 54 drives the CR motor 30 to move the carriage 28, and also drives the paper feed motor 31 to feed the printing paper P by a predetermined amount (step S20).

  As described above, the color inkjet printer 20 continuously performs the operations of step S14, step S16, step S18, and step S20. For example, when the paper feed amount of the printing paper P reaches a predetermined amount (step S22). The following operations are performed.

  First, as shown in FIGS. 9 (f) and 9 (g), the system controller 54 drives the CR motor 30 to move the carriage 28 to a predetermined position (hereinafter also referred to as a first position). Positioning is performed (step S24). Then, the movement amount from the reference position of the CR motor 30 is obtained based on the output pulse of the linear encoder 11, and the movement amount, in other words, the first position of the carriage 28 is stored (step S26).

  Next, as shown in FIGS. 9G and 9H, the system controller 54 drives the paper feed motor 31 to feed the printing paper P by a predetermined amount (step S28).

  Here, if the lower end of the printing paper P blocks the light emitted from the light emitting section 38 as shown in FIG. 9 (h) before the predetermined amount of paper feed is completed, the light emission is performed. Since the incident destination of the light emitted from the unit 38 changes from the printing paper P to the platen 26, the magnitude of the electrical signal that is the output value of the light receiving unit 40 of the reflective optical sensor 29 that receives the reflected light changes. . Then, the magnitude of this electrical signal is measured by the electrical signal measuring unit 66 to detect that the lower end of the printing paper P has passed the light. At this time, the system controller 54 obtains the movement amount from the reference position of the PF motor 31 based on the output pulse of the rotary encoder 13, and stores the movement amount, in other words, the feed amount of the printing paper P. (Step S32).

  On the contrary, if the lower end of the printing paper P does not block the emitted light before the predetermined amount of paper feeding is completed (step S30), the procedure proceeds to the above-described step S14.

  The case where the lower end of the printing paper P blocks the emitted light before the end of the predetermined amount of paper feeding will be described subsequently. The system controller 54 uses the information on the position of the carriage 28 stored in step S16 to determine which of the lower left end and the right end is sent later in the paper feed direction (step S34).

  For example, referring to FIG. 9B and FIG. 9E, the above-described position X1 is located on the right side in the main scanning direction on the drawing with respect to the above-described position X2. Therefore, in this case, it can be understood that the lower left end (shown in the upper right end of the printing paper P in the drawing) is sent behind in the paper feeding direction. On the contrary, when the position X1 is located on the left side in the drawing with respect to the position X2, the right end at the lower end is fed behind in the paper feeding direction.

  The positions X1 and X2 are stored in step S16 as described above, but from step S14 to step S20 has a loop structure as clearly shown in FIG. The location can be repeatedly recorded. The position X1 and the position X2 may be any of these stored positions.

  Based on the determined result, the carriage 28 is moved from the first position to be positioned at a predetermined position (hereinafter also referred to as a second position). That is, whether to set the second position to the downstream side in the main scanning direction as viewed from the first position or the upstream side is determined based on the determination result, and the carriage 28 is moved. This setting is performed (step S36). More specifically, as shown in FIGS. 9H and 9I, it is determined that the lower left end (shown in the upper right end of the printing paper P in the drawing) is sent later in the paper feeding direction. In this case, the second position is set on the downstream side in the main scanning direction (here, the main scanning direction is a direction from the left side to the right side in the drawing) when viewed from the first position. Conversely, when it is determined that the right end of the lower end is fed later in the paper feeding direction, the second position is set upstream in the main scanning direction as viewed from the first position. Then, the movement amount from the reference position of the CR motor 30 is obtained based on the output pulse of the linear encoder 11, and the movement amount, in other words, the second position of the carriage 28 is stored (step S38).

  As shown in FIG. 9 (i) and FIG. 9 (j), the predetermined amount of paper feeding is continuously performed, and then, as shown in FIG. 9 (j), before the predetermined amount of paper feeding is finished. When the lower end of the printing paper P blocks the light emitted from the light emitting unit 38 (step S40), the incident destination of the light emitted from the light emitting unit 38 changes from the printing paper P to the platen 26. The magnitude of the electrical signal that is the output value of the light receiving unit 40 of the reflective optical sensor 29 that has received the reflected light changes. Then, the magnitude of this electrical signal is measured by the electrical signal measuring unit 66 to detect that the lower end of the printing paper P has passed the light. At this time, the system controller 54 obtains the movement amount from the reference position of the PF motor 31 based on the output pulse of the rotary encoder 13, and stores the movement amount, in other words, the feed amount of the printing paper P. (Step S42).

  On the contrary, the case where the lower end of the printing paper P does not block the emitted light before the predetermined amount of paper feeding is finished (step S40) will be described later.

  The case where the lower end of the printing paper P blocks the emitted light before the predetermined amount of paper feeding is finished (step S40) will be described subsequently. The system controller 54 stores the first position of the carriage 28 stored in step S26, the second position of the carriage 28 stored in step S38, the feed amount of the printing paper P stored in step S32, and the step S42. From the stored feed amount of the printing paper P, the position in the paper feed direction of one of the left end and the right end at the lower end, which is fed later in the paper feed direction, is obtained.

  As described above, the printing paper P may be bent (obliquely) or fed. In this case, strictly speaking, it is the left end or the right end among the lower ends that are sent most backward in the paper feed direction. In the present embodiment, as indicated by a white arrow in FIG. 9A, the left end of the lower end (hereinafter also referred to as the lower left end) is sent most backward in the paper feed direction.

  A more detailed description will be given with reference to FIG. FIG. 11 is a diagram for explaining an example of a method for obtaining the position of one of the left and right ends of the lower end of the printing paper P that is fed later in the paper feeding direction.

  A straight line rising to the right indicated by a solid line in the drawing represents the lower end of the printing paper P. Further, the left end of the straight line shown in the drawing represents the right end (hereinafter also referred to as the lower right end) of the printing paper P, and the right end of the straight line represents the lower left end of the printing paper P. The reason why the left and right sides are reversed with respect to the straight line and the lower end of the printing paper P is that the paper feeding direction is from the upper side to the lower side of the drawing.

  Also, as shown in the figure, the first position stored in step S26 when the first position of the carriage 28 is the point M is a numerical value m. Similarly, the second position stored in step S38 when the second position of the carriage 28 is a point N is set as a numerical value n. For convenience, the numerical values m and n are values based on the position of the lower right end of the printing paper P in the main scanning direction, but are not limited to this and may be other positions.

  Further, paying attention to the paper feeding direction, the carriage 28 moves only in the main scanning direction. Therefore, the difference p between the positions of the point M and the point N in the figure is the same as the feeding amount of the printing paper P stored in step S32. This represents a difference from the feed amount of the printing paper P stored in step S42. Therefore, the difference p can be obtained from the numerical values stored in step S32 and step S42.

  Next, from the numerical values m, n, and p, the position in the paper feed direction of one of the left end and the right end at the lower end that is fed backward in the paper feed direction (the lower left end in this embodiment) is obtained. As shown in the figure, the position is represented by, for example, a difference q in the paper feed direction relative to the second position (point N). The method for obtaining the difference q is shown below.

First, the inclination θ of the printing paper P is obtained. As is apparent from the figure, since there is a relationship of tan θ = p / (nm), θ = tan−1 (p / (nm)).
Next, the distance a in the paper feed direction shown in FIG. 11 is obtained. As is apparent from the figure, since there is a relationship of (ap) / a = m / n, a = n · p / (nm).
Next, the distance b in the main scanning direction shown in FIG. 11 is obtained. The width of the printing paper (at the lower end) is known, and when this is r, b = r · cos θ, and b can be obtained by substituting the already obtained value for θ.
Further, as apparent from the figure, since there is a relationship of n / (b−n) = a / q, q = a · (b−n) / n, and a and b already obtained are substituted for this. By doing so, q can be obtained.

  In this way, either one of the left end and the right end at the lower end of the numerical value stored in step S26, step S32, step S38, and step S42 is sent later in the paper feed direction (in this embodiment, the lower value). The position in the paper feed direction at the left end is obtained (step S44).

  Next, a case where the lower end of the printing paper P does not block the emitted light before the predetermined amount of paper feeding is completed in step S40 will be described.

  In this case, a predetermined amount of paper is fed without obtaining the position in the paper feed direction of one of the lower left end and the right end (lower left end in the present embodiment) that is fed later in the paper feed direction. Then, the carriage 28 is moved in the main scanning direction, and ink is ejected from the print head 36 to perform printing on the printing paper P (step S46).

  When the next paper feed of the printing paper P is performed, the system controller 54 drives the CR motor 30 to move the carriage 28 to the second position for positioning (step S48). Then, the movement amount from the reference position of the CR motor 30 is obtained based on the output pulse of the linear encoder 11, and the movement amount, in other words, the second position of the carriage 28 is stored (step S50).

  Next, the system controller 54 drives the paper feed motor 31 to feed the printing paper P by a predetermined amount (step S52).

Then, similarly to step S40, it is determined whether or not the lower end of the printing paper P blocks the light emitted from the light emitting unit 38 before the predetermined amount of paper feed is completed (step S54). When the lower end of the printing paper P blocks the emitted light (step S54), the system controller 54 detects that the lower end of the printing paper P has passed the light by the method described above, and The feed amount of the printing paper P is stored (step S56).
On the contrary, if the lower end of the printing paper P does not block the emitted light (step S54), the procedure proceeds to the above-described step S46.

  If the lower end of the printing paper P blocks the emitted light before the predetermined amount of paper feeding is completed (step S54), the system controller 54 stores the first carriage 28 stored in step S26. The method already described from the position, the second position of the carriage 28 stored in step S50, the feeding amount of the printing paper P stored in step S32, and the feeding amount of the printing paper P stored in step S56. Is used to determine the position of one of the lower left end and the right end in the paper feed direction that is fed later in the paper feed direction (step S44).

  Note that a program for performing the above processing is stored in the EEPROM 58, and the program is executed by the system controller 54.

As described in the background art section, the printing paper P may be bent (obliquely) and fed (or paper fed). Therefore, the printing paper that emits light from a light emitting diode or the like and feeds the paper. Strictly speaking, the position of the lower end obtained by simply detecting the change in the output value of a light receiving sensor such as a photodiode due to the light being blocked is not the position sent most late in the paper feed direction, In view of the accuracy of grasping the lower end position of the printing apparatus, there is a possibility that problems may arise. Therefore, in this way, the change in the output value of the light receiving sensor due to the lower end of the printing paper P blocking light at a plurality of positions is detected. Then, based on this detection result, the position of one of the left end and the right end of the lower end to be fed backward in the paper feed direction is obtained, and the position of the lower end of the printing paper P is accurately grasped. As a result, the above problem can be solved.

  In the above, based on the positions of the first position and the second position in the main scanning direction, either one of the left end and the right end at the lower end is determined to be fed later in the paper feed direction. In the broad sense, the main scanning of the first position and the second position is also based on the position of the first position in the main scanning direction or the position of the second position in the main scanning direction and the distance between the two positions. It is included when it is determined based on the position of the direction.

  Further, in the above, in step S32 and step S42, the amount of movement of the PF motor 31 from the reference position is obtained, the amount of movement is stored as the feed amount of the printing paper P, and this difference is stored in the first position of the light receiving sensor. The feed amount of the printing paper from when the change in the output value is detected until the change in the output value of the light receiving sensor is detected at the second position is the reference position when the movement amount of the PF motor 21 is obtained in step S42. May be obtained as the position of the PF motor 31 in step S32. The same applies to the above-described procedure for obtaining a predetermined paper feed amount from the difference between the numerical values stored in step S32 and step S56.

  In the above description, the reflective optical sensor is used. However, the present invention is not limited to this. For example, the light emitting unit and the light receiving unit may be arranged so as to face each other in a direction perpendicular to the main scanning direction and the sub scanning direction, and the light emitting unit and the light receiving unit sandwich the printing medium.

  Moreover, in the above, although the 1st position and the 2nd position were made into the predetermined position, it is good also as arbitrary positions. Further, when the first position and the second position are set as the predetermined positions, the subsequent procedure for storing the first position and the second position, that is, step S26, step S38, or step S50 is omitted. May be. Even if the second position is an arbitrary position, if the second position is stored in step S38, the second position is not necessarily stored in step S50.

  In the above description, in step S10, after the movement of the carriage 28 in the main scanning direction reaches a predetermined number of times, it starts detecting that the edge of the printing paper P has passed light. Is not to be done. For example, the detection may be started from the first movement of the carriage 28 in the main scanning direction, or an ideal detection timing may be obtained by calculation or the like to minimize the number of detections. The same can be said for step S22.

  In the above description, as shown in FIG. 9B or 9E, it is detected that light has passed through the right end (left end in the drawing) of the printing paper P. Then, it is good also as detecting having passed the right end). Further, both the right end and the left end may be detected in order to increase the accuracy of determination.

=== Other Embodiments ===
As described above, the printing apparatus and the like according to the present invention have been described based on one embodiment. However, the above-described embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. Absent. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  Moreover, although the printing paper has been described as an example of the printing material, a film, a cloth, a thin metal plate, or the like may be used as the printing material.

  Further, a computer main body, a display device connectable to the computer main body, a printer according to the above-described embodiment connectable to the computer main body, an input device such as a mouse and a keyboard provided as necessary, a flexible disk drive A computer system having a device and a CD-ROM drive device can also be realized, and the computer system realized in this way is an overall system superior to the conventional system.

  The printer according to the above-described embodiment may have a part of functions or mechanisms respectively included in the computer main body, the display device, the input device, the flexible disk drive device, and the CD-ROM drive device. For example, the printer includes an image processing unit that performs image processing, a display unit that performs various displays, and a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. Also good.

In the above embodiment, a color ink jet printer has been described. However, the present invention can be applied to a monochrome ink jet printer, and can also be applied to printers other than the ink jet system. The present invention is generally applicable to a printing apparatus that prints on a printing medium, and can also be applied to, for example, a facsimile machine and a copier.
However, in a so-called ink jet type printing apparatus that performs printing by discharging ink from the print head, a high quality of the printing result is particularly required, and thus the merit by the above means becomes larger.

In the embodiment, the light emitting unit and the light receiving unit are moved in the main scanning direction to detect a change in the output value due to the lower end of the printing paper blocking the light at a plurality of positions. However, the present invention is not limited to this. For example, a plurality of reflective optical sensors may be prepared, and the change in the output value may be detected by each reflective optical sensor.
However, the above embodiment is more preferable in that the number of reflection type optical sensors to be prepared can be reduced by moving the light emitting unit and the light receiving unit in the main scanning direction.

In the above embodiment, a change in the output value of the light receiving sensor due to the lower end of the printing paper P blocking light at the first position and the second position that are different from each other in the main scanning direction is detected. The position of the main scanning direction, the position of the second position in the main scanning direction, and the printing medium from when the change of the output value is detected at the first position until the change of the output value is detected at the second position The position of one of the left end and the right end of the lower end to be fed later in the paper feed direction is determined based on the feed amount of the lower end. However, the present invention is not limited to this.
However, the above embodiment is more preferable in that the number of times of detecting the change in the output value of the light receiving sensor can be minimized and the procedure can be simplified. .

  Further, in the above embodiment, it is determined before moving the light emitting unit and the light receiving unit from the first position which of the left end and the right end of the lower end of the printing paper is sent behind in the paper feeding direction, Based on the determined result, it is determined whether the second position is set to the downstream side in the main scanning direction as viewed from the first position or to the upstream side. However, the present invention is not limited to this. It is not something. For example, after a change in the output value of the light receiving unit is detected at the first position, the light emitting unit and the light receiving unit are moved from the first position to either the upstream side or the downstream side in the main scanning direction, and light is emitted by the light emitting unit. When it is determined that the light has been applied to the printing paper P by the output value of the light receiving unit that has received the light, the second position is set on the same side as viewed from the first position, When it is determined that light is not applied to the printing paper P, the second position may be set on the opposite side as viewed from the determination side and the first position.

  If the second position is set on the side where the incident light is not printed paper if the light is radiated without taking any of the above steps, the printing paper is In order for the lower end to block light, there is a disadvantage that it is necessary to back feed the printing paper. The above two methods are common in that this inconvenience can be avoided, but the latter method requires that a temporary position is passed through when moving from the first position to the second position. Inefficient. Therefore, the above embodiment is more desirable in that such inefficiencies can be avoided.

Further, in the above embodiment, the output value of the light receiving unit is obtained by stopping the printing paper and moving the light emitting unit in the main scanning direction so that the light emitted from the light emitting unit blocks the edge of the printing paper. The position of the edge is detected and the position of the edge is identified, and based on this position, it is determined which of the lower left edge and the right edge of the printing paper is fed later in the paper feeding direction. It is not limited to.
However, since the operation of stopping the printing paper and moving the light emitting unit in the main scanning direction is the same as the operation for printing on the printing paper, information for efficiently performing the determination is obtained. The above embodiment is more preferable in that it can be performed.

Further, in the above embodiment, the output value of the light receiving unit is obtained by stopping the printing paper and moving the light emitting unit in the main scanning direction so that the light emitted from the light emitting unit blocks the edge of the printing paper. After detecting the change of the position and specifying the position of the edge, the printing paper is fed, the change of the output value of the light receiving unit is detected again, the position of the edge is specified, and based on the two specified positions of the edges Thus, it is determined which of the lower end and the right end of the lower end of the printing paper is fed later in the paper feeding direction, but the present invention is not limited to this.
However, by doing so, more information for the above determination is made, so that it is possible to accurately determine which of the lower left end and the right end is fed later in the paper feed direction. The above embodiment is more desirable.

In the above embodiment, the light emitting unit and the light receiving unit are provided in a movable carriage having a print head for forming dots. However, the present invention is not limited to this. For example, the carriage, the light emitting unit, and the light receiving unit may be configured to be separately movable in the main scanning direction.
However, the above embodiment is preferable in that the carriage, the light emitting unit, and the moving mechanism of the light receiving unit can be shared by doing in this way.

Moreover, in the said embodiment, although borderless printing was performed, it is not limited to this.
However, in the case of borderless printing, since printing is also performed on the lower end of the printing paper, it is necessary to accurately grasp the position of the lower end of the printing paper.

1 is a block diagram illustrating a configuration of a printing system as an example of the present invention. 2 is a schematic perspective view illustrating an example of a main configuration of the color inkjet printer 20. FIG. 4 is a schematic diagram for explaining an example of a reflective optical sensor 29. FIG. FIG. 2 is a diagram illustrating a configuration around a carriage 28 of an inkjet printer. 3 is an explanatory diagram schematically showing a configuration of a linear encoder 11 attached to a carriage 28. FIG. 4 is a timing chart showing waveforms of two output signals of the linear encoder 11 during normal rotation and reverse rotation of a CR motor. 2 is a block diagram illustrating an example of an electrical configuration of the color inkjet printer 20. FIG. 4 is an explanatory diagram showing a nozzle arrangement on the lower surface of the print head. FIG. 3 is a diagram schematically illustrating a positional relationship among the print head 36, the reflective optical sensor 29, and the printing paper P. FIG. It is a flowchart for demonstrating 1st embodiment. FIG. 6 is a diagram for explaining an example of a method for obtaining a position in one paper feeding direction that is fed backward in the paper feeding direction among the left end and the right end of the lower end of the printing paper P;

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Linear encoder 12 Linear encoder code board 13 Rotary encoder 14 Rotary encoder code board 20 Color inkjet printer 21 CRT
DESCRIPTION OF SYMBOLS 22 Paper stacker 24 Paper feed roller 25 Pulley 26 Platen 28 Carriage 29 Reflective optical sensor 30 Carriage motor 31 Paper feed motor 32 Pull belt 34 Guide rail 36 Print head 38 Light emitting part 40 Light receiving part 50 Buffer memory 52 Image buffer 54 System controller 56 Main memory 58 EEPROM
61 Main Scan Drive Circuit 62 Sub Scan Drive Circuit 63 Head Drive Circuit 65 Reflective Optical Sensor Control Circuit 66 Electrical Signal Measuring Unit 90 Computer 91 Video Driver 95 Application Program 96 Printer Driver 97 Resolution Conversion Module 98 Color Conversion Module 99 Halftone Module 100 Rasterizer 101 User interface display module 102 UI printer interface module

Claims (13)

A feeding means for feeding the supplied printing medium in a predetermined feeding direction;
Light emitting means for emitting light;
A light receiving sensor for receiving light emitted by the light emitting means,
In the printing apparatus for detecting a change in the output value of the light receiving sensor due to the printing medium sent by the feeding means blocking the light emitted by the light emitting means,
Changes in the output value due to the lower end of the printing medium blocking the light at a plurality of positions are detected, and based on the detection result, the lower end of the lower end and the right end are sent behind in the feeding direction. A printing apparatus characterized in that the position of either one of the feeding directions is obtained. The printing apparatus according to claim 1,
A printing apparatus, wherein ink is ejected from a print head to form dots on the substrate. The printing apparatus according to claim 1 or 2,
A printing apparatus, wherein the light emitting means and the light receiving sensor are moved in a main scanning direction to detect a change in the output value due to a lower end of the printing medium blocking the light at a plurality of positions. The printing apparatus according to claim 3.
Detecting a change in the output value due to the lower end of the printing medium blocking the light at different first and second positions in the main scanning direction;
The position of the first position in the main scanning direction, the position of the second position in the main scanning direction, and the change of the output value is detected at the second position after the change of the output value is detected at the first position. A printing apparatus characterized in that either one of the left end and the right end of the lower end to be fed backward in the feed direction is obtained based on the feed amount of the printing medium until the end. The printing apparatus according to claim 4,
It is determined before moving the light emitting means and the light receiving sensor from the first position which of the left end and the right end of the lower end is sent later in the feeding direction,
A printing apparatus that determines whether the second position is set on the downstream side in the main scanning direction as viewed from the first position or the upstream side based on the determined result. . The printing apparatus according to claim 5, wherein
Changes in the output value of the light receiving sensor caused by stopping the printing medium and moving the light emitting means in the main scanning direction so that the light emitted by the light emitting means blocks the edge of the printing medium. To identify the position of the end,
A printing apparatus that determines which of the left end and the right end of the lower end is sent later in the feeding direction based on the specified position of the end. The printing apparatus according to claim 6.
After specifying the position of the edge, the printing medium is fed by the feeding means,
Changes in the output value of the light receiving sensor caused by stopping the printing medium and moving the light emitting means in the main scanning direction so that the light emitted by the light emitting means blocks the edge of the printing medium. Is detected again, the position of the end is specified,
A printing apparatus that determines which of the left end and the right end of the lower end is sent later in the feeding direction based on the specified positions of the two ends. The printing apparatus according to any one of claims 3 to 7,
A printing apparatus comprising: a movable member having a print head for forming dots, wherein the light emitting means and the light receiving sensor are provided. The printing apparatus according to any one of claims 1 to 8,
A printing apparatus that performs printing on the entire surface of the substrate. A feeding means for feeding the supplied printing medium in a predetermined feeding direction;
Light emitting means for emitting light;
A light receiving sensor for receiving light emitted by the light emitting means,
Detecting a change in the output value of the light receiving sensor due to the printing medium sent by the feeding means blocking the light emitted by the light emitting means, ejecting ink from a print head to detect all of the printing medium. In a printing device that prints on the surface,
The light-emitting means and the light-receiving sensor are provided on a movable member that includes a print head for ejecting ink to form dots,
By moving the light emitting means and the light receiving sensor in the main scanning direction, the change in the output value due to the lower end of the printing medium blocking the light at different first and second positions in the main scanning direction. Detect
The position of the first position in the main scanning direction, the position of the second position in the main scanning direction, and the change of the output value is detected at the second position after the change of the output value is detected at the first position. Based on the feed amount of the printing medium until the end, the position of either one of the left end and the right end of the lower end to be sent later in the feed direction,
Changes in the output value of the light receiving sensor caused by stopping the printing medium and moving the light emitting means in the main scanning direction so that the light emitted by the light emitting means blocks the edge of the printing medium. To identify the position of the end,
After specifying the position of the edge, the printing medium is fed by the feeding means, the printing medium is stopped, and the light emitting means is moved in a main scanning direction, and the light emitted by the light emitting means is emitted. Detecting again the change in the output value of the light receiving sensor due to the light blocking the edge of the substrate, identify the position of the edge,
Based on the positions of the two specified ends, it is determined before moving the light emitting means and the light receiving sensor from the first position which one of the left end and the right end of the lower end is sent later in the feeding direction. And
A printing apparatus that determines whether the second position is set on the downstream side in the main scanning direction as viewed from the first position or the upstream side based on the determined result. . A feeding means for feeding the supplied printing medium in a predetermined feeding direction;
Light emitting means for emitting light;
A light receiving sensor for receiving light emitted by the light emitting means,
In the printing medium lower end determination method by the printing apparatus that detects a change in the output value of the light receiving sensor due to the printing body sent by the feeding means blocking the light emitted by the light emitting means,
Detecting a change in the output value due to the lower end of the printing medium blocking the light at a plurality of positions, and sending a later one of the left end and the right end of the lower end in the feeding direction based on the detection result. And a step of determining one of the positions in the feeding direction. A feeding means for feeding the supplied printing material in a predetermined feeding direction; a light emitting means for emitting light; and a light receiving sensor for receiving the light emitted by the light emitting means; In a printing apparatus that detects a change in the output value of the light receiving sensor due to the printing medium sent by the means blocking the light emitted by the light emitting means, the lower end of the printing medium is the light at a plurality of positions. To detect the change in the output value due to blocking, and to determine the position in the feed direction of one of the left end and the right end of the lower end that are sent later in the feed direction based on the detection result Computer program. A computer main body, a display device connectable to the computer main body, and a printing device connectable to the computer main body, a feeding means for feeding the supplied printing medium in a predetermined feeding direction, and for emitting light And a light receiving sensor for receiving the light emitted by the light emitting means, and the light receiving device by blocking the light emitted by the light emitting means by the printing medium sent by the sending means. A printing apparatus for detecting a change in an output value of a sensor, wherein a change in the output value due to a lower end of the printing medium blocking the light is detected at a plurality of positions, and the lower end is detected based on the detection result. A computer system comprising: a printing device that obtains a position in one of the left end and the right end of the feed that is sent later in the feed direction.

Images