JP5018987B2 - Liquid ejection device and computer system - Google Patents

Description

  The present invention relates to a liquid ejection apparatus and a computer system.

  A color ink jet printer which is a typical liquid ejecting apparatus is already well known. This color inkjet printer includes a print head as an example of an ink jet type ejection head that ejects ink as an example of liquid from nozzles, and ejects ink onto printing paper as an example of a medium to thereby print images and characters. Etc. are recorded.

The print head is supported by the carriage with the nozzle surface on which the nozzles are formed facing the print paper, and moves (main scan) in the width direction of the print paper along the guide member. Ink is ejected in synchronization with.
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 the case of borderless printing, since printing is performed on the entire surface of the printing paper, it is important to prevent a margin from being formed at the edge of the printed printing paper. In order to realize this, taking into consideration that the printing paper is bent (obliquely), it is slightly larger than the printing paper, in other words, has a certain margin compared to the size of the printing paper. It is effective to prepare prepared print data and perform printing on printing paper based on the print data.

  In addition, in order to reduce the problem of this method that ink is consumed wastefully when printing is performed on an area other than printing paper, the position of the side edge of the printing paper is detected and detected by the detection means. It is also effective to change the start position and the end position for ejecting ink according to the position of the side edge.

  However, when such a measure is executed, the printing operation is nearly finished due to the printing paper being bent (obliquely) and the detection means detects the lower end of the printing paper. There is a case. As in this example, if the start position and end position for ejecting ink are changed according to the detected position of the side edge in a state where the position of the side edge of the print sheet is not properly detected, a margin is added to the print sheet. The problem arises.

  The present invention has been made in view of such problems, and an object of the present invention is to realize a liquid ejecting apparatus and a computer system that do not cause a margin in a medium.

The main present invention has a movable discharge head for discharging a liquid, a detection means for detecting the position of the end of the medium, and a feed mechanism for feeding the medium, and the detection means A liquid discharge apparatus that repeats a detection operation for detecting the position of the end, a feed operation for sending the medium by the feed mechanism, and a discharge operation for discharging liquid from the moving discharge head to the medium, Detected in a certain detection operation in a liquid ejection device that changes at least one of a start position and an end position for ejecting liquid from the moving ejection head in accordance with the position of the end detected in the detection operation When the distance between the end position and the end position detected in the detection operation before the detection operation exceeds a predetermined value, the detection is performed in the previous detection operation. Based on the position of said end, a liquid discharge apparatus characterized by determining at least one of the end position and the starting position.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

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. It is a flowchart for demonstrating 1st embodiment. It is explanatory drawing for demonstrating how to obtain | require an ink discharge start position and an ink discharge end position. 3 is a diagram schematically illustrating a positional relationship among the print head 36, the reflective optical sensor 29, and the printing paper P. 3 is a diagram schematically illustrating a positional relationship among the print head 36, the reflective optical sensor 29, and the printing paper P. It is explanatory drawing which showed the external appearance structure of the computer system. It is a block diagram which shows the structure of the computer system shown in FIG.

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

Application Example 1 A first movement in the main scanning direction, a second movement in the main scanning direction, the second movement after the first movement, and the main movement in the main scanning direction A moving member that performs the third movement and the third movement after the second movement; and a discharge head provided in the moving member, the discharge head for discharging a liquid; Detecting means provided in the moving member, the detecting means for detecting the position of the end of the medium, and the medium between the first movement and the second movement in the sub-scanning direction. A feed mechanism for feeding the medium at least once in the sub-scanning direction between the second movement and the third movement, and the detection means includes the medium At least one of the positions of the two ends having different positions in the main scanning direction. The end of the first side is detected in the first movement, the detecting means detects the position of the one end in the second movement, and the discharge head is In the second movement, when the distance between the position of the one end detected in the movement and the position of the one end detected in the second movement is smaller than a predetermined value, The liquid is ejected in the third movement to a position corresponding to the detected position of the one end, and the ejection head detects the end of the one side detected in the first movement. When the distance between the position and the position of the one side edge detected in the second movement is larger than a predetermined value, the position of the one side edge detected in the first movement is In the corresponding position, the liquid is moved in the third movement. Out to, liquid discharge apparatus.
Application Example 2 A first movement in the main scanning direction, a second movement in the main scanning direction, the second movement after the first movement, and the main movement in the main scanning direction A moving member that performs the third movement and the third movement after the second movement; and a discharge head provided in the moving member, the discharge head for discharging a liquid; Detecting means provided in the moving member, the detecting means for detecting the position of the end of the medium, and the medium between the first movement and the second movement in the sub-scanning direction. A feeding mechanism for feeding the medium at least once in the sub-scanning direction between the second movement and the third movement, and the medium has a rectangular shape. The discharge head has a position of an edge of the medium detected in the first movement. Detected in the second movement when the position of the edge of the long side of the medium is the position of the end of the long side of the medium. The liquid is ejected in the third movement to a position corresponding to the position of the edge of the long side of the medium, and the ejection head detects the position of the edge of the medium detected in the first movement. In the first movement, the position of the edge of the long side of the medium, and the position of the edge of the medium detected in the second movement is the position of the edge of the short side of the medium. A liquid ejection apparatus that ejects the liquid in the third movement to a position corresponding to the detected position of the long side edge of the medium.
Application Example 3 A first movement in the main scanning direction, a second movement in the main scanning direction, the second movement after the first movement, and the main movement in the main scanning direction A moving member that performs the third movement and the third movement after the second movement; and a discharge head provided in the moving member, the discharge head for discharging a liquid; Detecting means provided in the moving member, the detecting means for detecting the position of the end of the medium, and the medium between the first movement and the second movement in the sub-scanning direction. A feeding mechanism for feeding the medium at least once in the sub-scanning direction between the second movement and the third movement, and the medium has a rectangular shape. The ejection head has an end position of the medium detected in the first movement, The medium detected in the second movement when the position of the edge of the medium detected in the second movement is the position of the side edge of the medium. The liquid is ejected in the third movement to a position corresponding to the position of the side edge of the medium, and the ejection head detects that the position of the edge of the medium detected in the first movement is the side edge of the medium. And when the position of the end of the medium detected in the second movement is the position of the lower end of the medium, the position of the side edge of the medium detected in the first movement is A liquid ejecting apparatus that ejects the liquid in the third movement in a corresponding position.
Application Example 4 The liquid discharge apparatus according to any one of Application Examples 1 to 3, wherein the discharge head discharges the liquid in the second movement.
Application Example 5 A moving member that repeatedly moves in the main scanning direction, an ejection head provided in the moving member, the ejection head for ejecting liquid, and the position of the end of the medium Detecting means for detecting an end position on at least one of two end positions having different positions in the main scanning direction, the detecting means provided in the moving member, and the medium A feed mechanism for repeatedly feeding in the sub-scanning direction, and the ejection head detects the position of the end on the one side detected in the N-th (N ≠ 1) detection operation, and the (N-1) th time. When the distance from the position of the one side edge detected in the detection operation is smaller than a predetermined value, the position according to the position of the one side edge detected in the N-th detection operation, The liquid is discharged, and the discharge head is The distance between the position of the one end detected in the Nth detection operation and the position of the one end detected in the N-1th detection operation is greater than the predetermined value. In this case, the liquid ejecting apparatus ejects the liquid to a position corresponding to the position of the end on the one side detected in the N-1th sensing operation.
Application Example 6 A moving member that repeatedly moves in the main scanning direction, an ejection head provided in the moving member, the ejection head for ejecting liquid, and a detection provided in the moving member Means for detecting the position of the edge of the medium, and a feed mechanism for repeatedly feeding the medium in the sub-scanning direction, the medium being a rectangular medium, In the ejection head, the position of the end of the medium detected in the N-1th (N ≠ 1) detection operation is the position of the end of the long side of the medium, and is detected in the Nth detection operation. When the position of the end of the medium is the position of the end of the long side of the medium, the liquid is placed at a position corresponding to the position of the end of the long side of the medium detected in the N-th detection operation. The discharge head is discharged from the N-1th test. The position of the end of the medium detected in the operation is the position of the end of the long side of the medium, and the position of the end of the medium detected in the N-th detection operation is the end of the short side of the medium. A liquid ejecting apparatus that ejects the liquid to a position corresponding to the position of the end of the long side of the medium detected in the N-1th sensing operation.
Application Example 7 A moving member that repeatedly moves in the main scanning direction, an ejection head provided in the moving member, the ejection head for ejecting liquid, and a detection provided in the moving member Means for detecting the position of the edge of the medium, and a feeding mechanism for repeatedly feeding the medium in the sub-scanning direction, the medium being a rectangular medium, In the ejection head, the position of the edge of the medium detected in the N-1th (N ≠ 1) detection operation is the position of the side edge of the medium, and the medium is detected in the Nth detection operation. When the position of the end of the medium is the position of the side end of the medium, the liquid is discharged to a position corresponding to the position of the side end of the medium detected in the N-th detection operation, and the discharge head Is the N-1th detection operation. When the known position of the edge of the medium is the position of the side edge of the medium, and the position of the edge of the medium detected in the N-th detection operation is the position of the lower end of the medium, A liquid ejection apparatus that ejects the liquid at a position corresponding to the position of the side edge of the medium detected in the N-1th detection operation.
[Application Example 8] The liquid ejection apparatus according to any one of Application Example 5 to Application Example 7, wherein the ejection head moves the liquid in the movement in which the detection unit performs the N-1th detection operation. A liquid discharge device for discharging liquid.
Application Example 9 In the liquid ejection device according to any one of Application Examples 1 to 8, the detection unit includes a light receiving sensor, and the ejection head includes a plurality of ejection heads along the sub-scanning direction. The nozzle has a nozzle, and the medium is transported from the upstream side in the sub-scanning direction to the downstream side in the sub-scanning direction, and the plurality of nozzles are positioned on the downstream side of the light receiving sensor in the sub-scanning direction. A liquid discharge apparatus including a nozzle, wherein the discharge head discharges the liquid from a nozzle located on the downstream side of the light receiving sensor in the sub-scanning direction.
Application Example 10 In the liquid ejection apparatus according to any one of Application Examples 1 to 9, the liquid ejection apparatus ejects liquid on the entire surface of the medium.
Application Example 11 In the liquid discharge apparatus according to any one of Application Examples 1 to 10, the liquid discharge apparatus according to any one of Application Example 1 to Application Example 10 is a start position at which the liquid is discharged by the discharge head that moves in the main scan direction. The liquid ejecting apparatus, wherein the start position of the medium changes in accordance with the position of the end of the medium detected by the detecting means.
Application Example 12 A computer system comprising the liquid ejection device according to any one of Application Examples 1 to 11, a computer main body connectable to the liquid ejection device, and a display device connectable to the computer main body. .
Alternatively, the following application examples may be used. A movable ejection head for ejecting the liquid; a detecting means for detecting the position of the end of the medium; and a feed mechanism for feeding the medium. The position of the end is detected by the detecting means. A liquid discharge apparatus that repeats a detection operation to detect, a feed operation to send the medium by the feed mechanism, and a discharge operation to discharge liquid to the medium from the moving discharge head, and is detected in the detection operation. In the liquid ejection apparatus that changes at least one of a start position and an end position at which liquid is ejected from the moving ejection head in accordance with the position of the end, the position of the end detected in a certain detection operation; When the distance from the end position detected in the detection operation before the detection operation exceeds a predetermined value, the end of the edge detected in the previous detection operation is detected. Based on the location, the liquid ejecting apparatus characterized by determining at least one of the end position and the starting position.

  When the distance between the position of the edge detected in a certain detection operation and the position of the edge detected in the detection operation before the detection operation exceeds a predetermined value, the distance was detected in the previous detection operation. By determining at least one of the start position and the end position based on the position of the end, it is possible to avoid erroneously generating a blank in the medium.

When the distance between the end position detected in the Nth detection operation and the end position detected in the (N-1) th detection operation exceeds a predetermined value, N-1 At least one of the start position and the end position may be determined based on the position of the end detected in the detection operation for the second time.
By doing so, at least one of the start position and the end position can be determined more appropriately.

The liquid may be discharged over the entire surface of the medium.
In the case where the liquid is ejected on the entire surface of the medium, the liquid is also ejected to the edge of the medium, so that the merit of the above means is further increased.

The detection means includes a light emitting means for emitting light, and a light receiving sensor for receiving the light moving in the main scanning direction according to the movement of the light emitting means in the main scanning direction, The position of the end may be detected based on the change in the output value of the light receiving sensor caused by the light emitted by the light emitting means moving in the main scanning direction blocking the end.
In this way, the position of the end can be detected more easily.

Further, two ends whose positions in the main scanning direction are different based on a change in an output value of the light receiving sensor due to light emitted from the light emitting means moving in the main scanning direction blocking the end. The position is detected in the detection operation, the start position is changed according to one of the detected two end positions, and the other of the two detected end positions is set. Accordingly, the end position may be changed.
In this way, the above-described effect, that is, the effect that it is possible to avoid erroneously creating a blank in the medium, is more remarkably exhibited.

The detection unit may be provided on a movable member that includes the ejection head and is movable.
If it does in this way, the moving mechanism of a moving member and a detection means can be made shared.

The light emitted by the light emitting means moving in the main scanning direction while moving the moving member in the main scanning direction is based on a change in the output value of the light receiving sensor due to blocking the end. The end position may be detected, and the liquid may be discharged from the discharge head onto the medium.
In this way, an efficient operation of the liquid ejection device can be realized.

The ejection head includes a plurality of nozzles, and the detection unit is provided side by side in the main scanning direction with a nozzle located on the most upstream side in the feed direction among the plurality of nozzles. It is good.
In such a case, since there is a high possibility that a margin is erroneously generated in the medium, the above-described effect, that is, the effect that a margin is not erroneously generated in the medium is more effectively exhibited.

Further, the ejection head has a plurality of nozzles, and when the position of the end is not detected in the detection operation, from the nozzles located upstream in the medium feeding direction among the plurality of nozzles. The liquid may not be discharged.
In such a case, it is possible to realize a liquid ejection device that reduces the amount of liquid consumption.

The liquid may be ink, and the liquid ejection device may be a printing device that performs printing on a printing medium that is the medium by ejecting ink from the ejection head.
In such a case, it is possible to realize a printing apparatus that exhibits the effects described above.

A movable ejection head for ejecting the liquid; a detection means for detecting the position of the edge of the medium; and a feed mechanism for feeding the medium. A liquid discharge apparatus that repeats a detection operation for detecting a position, a feed operation for feeding the medium by the feed mechanism, and a discharge operation for discharging a liquid from the moving discharge head to the medium. Detected in the N-th detection operation in a liquid discharge apparatus that changes at least one of a start position and an end position for discharging liquid from the moving discharge head according to the detected position of the end. When the distance between the end position and the end position detected in the (N-1) th detection operation exceeds a predetermined value, the N-1th detection operation is performed. Based on the detected position of the end, at least one of the start position and the end position is determined, the liquid is ejected on the entire surface of the medium, and the detection means emits light. And a light receiving sensor for receiving the light that moves in the main scanning direction according to the movement of the light emitting means in the main scanning direction, and emits light from the light emitting means that moves in the main scanning direction. Based on the change in the output value of the light receiving sensor due to the light being blocked by the end, the positions of the two ends having different positions in the main scanning direction are detected in the detection operation. The start position is changed according to one of the two end positions, and the end position is changed according to the other of the two detected end positions, and the ejection head is changed. Ready to move The moving means is provided with the detecting means, and the light emitted by the light emitting means moving in the main scanning direction while moving the moving member in the main scanning direction blocks the end. Based on the change in the output value of the light receiving sensor, the position of the end is detected, and liquid is discharged from the discharge head onto the medium. The discharge head has a plurality of nozzles, Among the plurality of nozzles, the nozzle located on the most upstream side in the feed direction is provided side by side in the main scanning direction, and when the position of the end is not detected in the detection operation, the plurality of nozzles Among the nozzles, liquid is not ejected from nozzles located upstream in the medium feeding direction, the liquid is ink, and the liquid ejection device ejects ink from the ejection head. By doing so, it is also possible to realize a liquid ejecting apparatus that is a printing apparatus that performs printing on the printing medium as the medium.
In this way, the effects of the present invention can be achieved most effectively because all the effects described above can be achieved.

A computer main body, a display device connectable to the computer main body, and a liquid discharge device connectable to the computer main body, the movable discharge head for discharging the liquid, and the position of the end of the medium are detected And a feeding mechanism for feeding the medium, a sensing operation for detecting the position of the end by the sensing means, a feeding operation for feeding the medium by the feeding mechanism, and the moving mechanism. A liquid discharge device that repeatedly discharges liquid from the discharge head onto the medium, and a start position for discharging liquid from the moving discharge head according to the position of the end detected in the detection operation And a liquid ejecting apparatus that changes at least one of the end positions, the position of the end detected in a detection operation, When the distance from the end position detected in the detection operation exceeds a predetermined value, the start position and the end position are determined based on the end position detected in the previous detection operation. A computer system including a liquid ejection device that determines at least one of them can be realized.
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 liquid ejection device. The printing system including the color inkjet printer 20 and the computer 90 can also be called a “liquid ejecting 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. The carriage 28 is mounted with a print head 36 as an example of an ejection head having a large number of nozzles, and a reflective optical sensor 29 as an example of a detection means described in detail later.

  The printing paper P is taken up by the paper feed roller 24 from the paper stacker 22 and fed on the surface of the platen 26 in a paper feeding direction (hereinafter also referred to as a sub-scanning direction) as a predetermined feeding direction. 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 includes a paper feed motor (hereinafter also referred to as a PF motor) 31 that feeds paper as an example of a feed mechanism, and a print head 36 that ejects ink as an example of liquid onto the print paper P. A carriage 28 that is fixed and driven in the main scanning direction, a carriage motor (hereinafter also referred to as a CR motor) 30 that drives the carriage 28, a linear encoder 11 that is fixed to the carriage 28, and slits at predetermined intervals. The formed 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 that is driven by the PF motor 31 to convey the printing paper P Driven by the feed roller 24, a pulley 25 attached to the rotating shaft of the CR motor 30, and the pulley 25. And a pull belt 32.

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 nozzle arrangement of print head, etc. ===
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, a yellow nozzle row, a magenta nozzle row, and a cyan nozzle row arranged on a straight line along the sub-scanning direction. As shown in the figure, each nozzle row is provided in two rows. In this specification, each nozzle row is designated as a first black nozzle row, a second black nozzle row, a first yellow nozzle row, They are called a two yellow nozzle row, a first magenta nozzle row, a second magenta nozzle row, a first cyan nozzle row, and a second cyan nozzle row.

  The black nozzle row (indicated by white circles) has 360 nozzles # 1 to # 360. Of these nozzles, odd-numbered nozzles # 1, # 3,..., # 359 are in the first black nozzle row, and even-numbered nozzles # 2, # 4,. Belongs to the nozzle row. The nozzles # 1, # 3,..., # 359 in the first black nozzle row 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”. 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 nozzles # 2, # 4,..., # 360 in the second black nozzle row are also arranged at a constant nozzle pitch k · D (nozzle pitch k = 4) along the sub-scanning direction. However, as shown in the figure, the position of each nozzle in the sub-scanning direction is shifted from the position of each nozzle in the first black nozzle row in the sub-scanning direction. In the example of FIG. 8, the amount of deviation is ½ · k · D (k = 4).

  The same applies to the yellow nozzle row (indicated by white triangles), the magenta nozzle row (indicated by white squares), and the cyan nozzle row (indicated by white rhombuses). That is, each nozzle row has 360 nozzles # 1 to # 360, of which odd-numbered nozzles # 1, # 3,..., # 359 are in the first row, # 2, # 4, ..., # 360 belongs to the second column. The nozzle rows are arranged at a constant nozzle pitch k · D along the sub-scanning direction, and the positions of the nozzles in the second row in the sub-scanning direction are the same as those in the sub-scanning direction of the nozzles in the first row. Compared with the position, it is shifted by ½ · k · D (k = 4).

  That is, the nozzle group arranged in the print head 36 has a zigzag shape. During printing, while the print head 36 moves at a constant speed in the main scanning direction together with the carriage 28, ink droplets are ejected from each nozzle. Discharged. However, depending on the printing method, not all nozzles are always used, and only some nozzles may be used.

  The reflective optical sensor 29 described above is attached to the carriage 28 together with the print head 36. In the present embodiment, the position of the reflective optical sensor 29 in the sub-scanning direction is as shown in the figure. This coincides with the position of the nozzle # 360 in the sub-scanning direction.

=== 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 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 is performed. From the movement of the carriage 28 in the direction, 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).

  Then, a counter (not shown) for counting the following series of repeated operations is prepared, and the system controller 54 resets the counter (step S14). Such a reset is realized, for example, by setting a counter value N to 0. Next, the system controller 54 adds 1 to the value N of the counter (step S16), and as shown in FIGS. 9A and 9B, ink is supplied from the print head 36 provided in the carriage 28. In order to perform borderless printing by discharging, the main scanning drive circuit 61 drives the CR motor 30 to move the carriage 28 (step S18). Eventually, as shown in FIG. 9B, the light emitted from the light emitting section 38 blocks the edge of the printing paper P (step S20). 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 the electric signal is measured by the electric signal measuring unit 66 to detect that the light has passed through the end of the printing paper P.

  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, the position is also referred to as position A) is N. This is stored as the second data (step S22).

  As shown in FIGS. 9B and 9C, the system controller 54 moves the carriage 28 even after the above-described step S16 and step S18, and the print head 36 provided in the carriage 28. Ink is then discharged to perform borderless printing (step S24).

  Eventually, as shown in FIG. 9C, the light emitted from the light emitting section 38 blocks the end of the printing paper P (the end in the main scanning direction is different from the end blocked in step S20). (Step S26). At this time, since the incident destination of the light emitted from the light emitting unit 38 is changed from the printing paper P to the platen 26, 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 the electric signal is measured by the electric signal measuring unit 66 to detect that the light has passed through the end of the printing paper P.

  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, the position is also referred to as position B) is N. The second data is stored (step S28).

  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. A predetermined amount of paper P is fed to prepare for the next borderless printing (step S30).

  Next, as shown in FIGS. 9D and 9E, the system controller 54 performs main scan driving in order to perform borderless printing by ejecting ink from the print head 36 provided in the carriage 28. The CR motor 30 is driven by the circuit 61 to move the carriage 28 (step S18). Prior to this operation, the ink discharge start position and the ink discharge end position of the print head 36 are determined (step S32 to step S48). A method for determining the ink discharge start position and the ink discharge end position will be described later.

  Next, the procedure returns to step S16, and the system controller 54 adds 1 to the value N of the counter (step S16), and thereafter, as shown in FIGS. 9 (d), 9 (e), and 9 (f). As described above, the steps S18 to S48 described above are executed. At this time, the system controller 54 controls the head drive circuit 63 to start ink discharge from the determined ink discharge start position, and ends ink discharge at the determined ink discharge end position.

  The subsequent procedure is a repetition of step S16 to step S48 as shown in the loop structure in the flowchart of FIG.

  Next, an example of how to obtain the ink discharge start position and the ink discharge end position will be described with reference to FIG. 10 and FIG. FIG. 11 is an explanatory diagram for explaining how to obtain the ink discharge start position and the ink discharge end position.

  First, the system controller 54 stores the Nth position A (indicated by a circle in FIG. 11) stored in step S22 and the (N-1) th position A stored in step S22 in the previous iteration procedure. The absolute value a of the difference (indicated by a dotted circle in FIG. 11) is obtained, and this value is compared with a predetermined value p (step S38).

  Here, if the absolute value a is smaller than the predetermined value p, a start position for ejecting ink is determined based on the Nth position A (step S40). For example, as shown in FIGS. 11 (a) and 11 (c), a start position (FIG. 11 (a) and FIG. 11 (c)) at which ink is discharged with a margin of a distance α from the Nth position A. The position is indicated by a square mark in FIG.

  On the contrary, when the absolute value a is larger than the predetermined value p, the start position for ejecting ink is determined based on the (N−1) th position A instead of the Nth position A (step S42). ). For example, as shown in FIG. 11 (b), a start position (indicated by a square mark in FIG. 11 (b)) at which ink is discharged with a margin of a distance α from the (N-1) th position A is indicated. decide.

  Similarly, the system controller 54 stores the Nth position B (indicated by a triangle in FIG. 11) stored in step S28 and the (N-1) th position stored in step S28 in the previous iteration procedure. An absolute value b of a difference between B (indicated by a dotted triangle in FIG. 11) is obtained, and this value is compared with a predetermined value p (step S44).

  Here, if the absolute value b is smaller than the predetermined value p, a start position for ejecting ink is determined based on the Nth position B (step S46). For example, as shown in FIGS. 11 (a) and 11 (b), an end position (FIGS. 11 (a) and 11 (b)) at which ink is discharged with a margin of a distance α from the Nth position B. The position is indicated by a cross in FIG.

  On the contrary, when the absolute value b is larger than the predetermined value p, the end position for ejecting ink is determined based on the (N−1) th position B instead of the Nth position B (step S48). ). For example, as shown in FIG. 11 (c), an end position (indicated by an x mark in FIG. 11 (c)) at which ink is discharged with a margin of a distance α from the (N-1) th position B is shown. decide.

  Note that the margin α is set based on, for example, a detection error when detecting the edge of the printing paper P in consideration of the fact that unnecessary margins are not generated on the printing paper P. A method of setting the predetermined value p will be described later. In the above description, the margin α and the predetermined value p are common values for determining the start position and the end position, but different values may be set. .

  In step S38, the system controller 54 determines the absolute value a of the difference between the Nth position A stored in step S22 and the N−1th position A stored in step S22 in the previous iteration procedure. This value is compared with a predetermined value p, but when N = 1 (step S32), since the (N-1) th position A is not stored, the comparison is performed. Without starting, the start position for ejecting ink is determined based on the N (= 1) th position A (step S34). Similarly, in step S44 described above, the system controller 54 determines the absolute value of the difference between the Nth position B stored in step S28 and the N−1th position B stored in step S28 in the previous iteration procedure. b is obtained, and this value is compared with a predetermined value p. If N = 1 (step S32), the N (= 1) th position is obtained without performing the comparison. An end position for ejecting ink is determined based on B (step S36).

  Next, with reference to FIG. 11, FIG. 9, FIG. 12, FIG. 9, the situation in which the above-described situation (that is, the situation shown in FIGS. 13 will be used for explanation. 12 and 13 are diagrams schematically showing the positional relationship among the print head 36, the reflective optical sensor 29, and the printing paper P. FIG.

  For a while after the start of the detection operation for detecting the position of the edge of the printing paper P, as shown in FIGS. 9B, 9C, 9E, and 9F, The reflective optical sensor 29 detects the side edge of the printing paper P. In such a case, as shown in FIG. 11A, both the absolute value a and the absolute value b are relatively small values. 11A corresponds to FIG. 9, and the position of the carriage 28 when the end of the printing paper P is detected in FIG. 9B is indicated by a dotted circle in FIG. 11A. The position of the carriage 28 when the end of the printing paper P is detected in FIG. 9C is the N-1th position A, and is indicated by the dotted triangle in FIG. The position of the carriage 28 when the edge of the printing paper P is detected in FIG. 9E is the (N−1) th position B, and the Nth position A indicated by a circle in FIG. The position of the carriage 28 when the edge of the printing paper P is detected in FIG. 9 (f) is the Nth position B indicated by a triangle in FIG. 11 (a).

  Thereafter, when the operation of detecting the position of the edge of the printing paper P, the operation of feeding the printing paper P by the paper feed roller 24, and the operation of ejecting ink onto the printing paper P are repeated, the reflection type optical The relative positional relationship between the sensor 29 and the printing paper P is as shown in FIG. As shown in FIGS. 12A to 12C, in order to perform borderless printing by ejecting ink from the print head 36 provided on the carriage 28 from such a state, the system controller 54 performs main scanning driving. When the CR motor 30 is driven by the circuit 61 to move the carriage 28, the reflective optical sensor 29 detects the side edge of the printing paper P (FIGS. 12B and 12C).

  However, as the next step, as shown in FIGS. 12C and 12D, the system controller 54 drives the paper feed motor 31 to feed the printing paper P by a predetermined amount. As shown in FIGS. 12D to 12F, when the system controller 54 drives the CR motor 30 by the main scanning drive circuit 61 and moves the carriage 28, the printing paper P is bent (becomes slanted). For this reason, the reflective optical sensor 29 may detect the lower end of the printing paper P (FIG. 12E).

  In this situation, if the start position for ejecting ink is determined based on the position of the carriage 28 when the lower end of the print sheet P is detected, and the ink is ejected from the determined start position, the print sheet A margin is generated in the lower right part of P (the upper left part of the printing paper P in FIG. 12). In such a case, in order to avoid such an inconvenience, the start position for ejecting ink is determined based on the position of the carriage 28 when the side edge of the printing paper P is detected in FIG.

  Also, the difference between the position of the carriage 28 when the side edge of the printing paper P is detected in FIG. 12B and the position of the carriage 28 when the lower edge of the printing paper P is detected in FIG. Therefore, when the absolute value a is larger than the predetermined value p, the side edge of the printing paper P is detected in FIG. 12B. The start position is determined based on the position of the carriage 28 at the time. Therefore, the predetermined value p is, for example, the position of the carriage 28 when the side edge of the printing paper P is detected in FIG. 9B and the carriage when the side edge of the printing paper P is detected in FIG. 28, the position of the carriage 28 when the side edge of the printing paper P is detected in FIG. 12B, and the carriage 28 when the lower edge of the printing paper P is detected in FIG. It is set appropriately in consideration of the difference between the position of

  11B corresponds to FIG. 12, and the position of the carriage 28 when the edge of the printing paper P is detected in FIG. 12B is indicated by a dotted circle in FIG. 11B. The position of the carriage 28 when the edge of the printing paper P is detected in FIG. 12C is the N−1th position A, and is indicated by the dotted triangle in FIG. 11B. The position of the carriage 28 when it is the (N-1) th position B and the edge of the printing paper P is detected in FIG. 12 (e) is the Nth position A indicated by a circle in FIG. 11 (b). The position of the carriage 28 when the edge of the printing paper P is detected in FIG. 12 (f) is the Nth position B indicated by a triangle in FIG. 11 (b).

  Next, pay attention to FIG. 13 shows a state in which the relative positional relationship between the reflective optical sensor 29 and the printing paper P is the same as that in FIG. 12 described above, and the printing paper P is bent in the opposite direction to that in FIG. is there. In such a case, if the system controller 54 drives the CR motor 30 by the main scanning drive circuit 61 and moves the carriage 28 as shown in FIGS. The sensor 29 detects the side edge of the printing paper P (FIGS. 13 (b) and 13 (c)), which is the same as that already described with reference to FIG. c) and FIG. 13 (d), after the system controller 54 feeds the printing paper P by a predetermined amount, the system controller 54, as shown in FIGS. 13 (d) to 13 (f), When the CR motor 30 is driven by the main scanning drive circuit 61 to move the carriage 28, the reflective optical sensor 29 detects the lower end of the printing paper P in the state shown in FIG.

  In such a situation, based on the position of the carriage 28 when the lower end of the printing paper P is detected, an end position for ejecting ink is determined, and ink ejection is terminated at the determined end position. A margin is generated in the lower left part of the printing paper P (the upper right part of the printing paper P in FIG. 13). In such a case, in order to avoid such an inconvenience, the end position for ejecting ink is determined based on the position of the carriage 28 when the side edge of the printing paper P is detected in FIG.

  Further, the difference between the position of the carriage 28 when the side edge of the printing paper P is detected in FIG. 13C and the position of the carriage 28 when the lower edge of the printing paper P is detected in FIG. Therefore, if the absolute value b is larger than the predetermined value p, the side edge of the printing paper P is detected in FIG. 13C. The end position is determined based on the position of the carriage 28 at that time. Accordingly, the predetermined value p is, for example, the position of the carriage 28 when the side edge of the printing paper P is detected in FIG. 9C and the carriage when the side edge of the printing paper P is detected in FIG. 28, the position of the carriage 28 when the side edge of the printing paper P is detected in FIG. 13C, and the carriage 28 when the lower edge of the printing paper P is detected in FIG. It is set appropriately in consideration of the difference between the position of

  11C corresponds to FIG. 13, and the position of the carriage 28 when the edge of the printing paper P is detected in FIG. 13B is indicated by a dotted circle in FIG. 11C. The position of the carriage 28 when the end of the printing paper P is detected in FIG. 13C is the N-1th position A, and is indicated by the dotted triangle in FIG. 11C. The position of the carriage 28 when it is the (N-1) th position B and the edge of the printing paper P is detected in FIG. 13 (e) is the Nth position A indicated by a circle in FIG. 11 (c). The position of the carriage 28 when the edge of the printing paper P is detected in FIG. 13 (f) is the Nth position B indicated by a triangle in FIG. 11 (c).

  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 section, the detection means detects the position of the side edge of the printing paper in order to reduce the problem of wasteful ink consumption due to printing on areas other than the printing paper. Although it is effective to change the start position and the end position for ejecting ink according to the detected position of the side edge, the printing paper is bent (obliquely) when such a measure is executed. For this reason, there is a case where the printing operation is almost finished and the detection unit detects the lower end of the printing paper. As in this example, if the start position and end position for ejecting ink are changed according to the detected position of the side edge in a state where the position of the side edge of the print sheet is not properly detected, a margin is added to the print sheet. The problem arises.

  Therefore, as described above, when the distance between the end position detected in a certain detection operation and the end position detected in the detection operation before the detection operation exceeds a predetermined value, the previous position is detected. By determining at least one of the start position and the end position based on the position of the edge detected in the detection operation, it is possible to avoid erroneously generating a blank in the printing paper. Become.

=== Other Embodiments ===
As mentioned above, although the liquid discharge apparatus etc. which concern on this invention have been demonstrated based on one Embodiment, Embodiment mentioned above is for making an understanding of this invention easy, and limits this invention. is not. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

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

  In the above-described embodiment, the printing apparatus has been described as an example of the liquid ejection apparatus. However, the present invention is not limited to this. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, liquid vaporizer, organic EL manufacturing apparatus (particularly polymer EL manufacturing apparatus), display manufacturing apparatus, film formation You may apply the same technique as this embodiment to an apparatus, a DNA chip manufacturing apparatus, etc. Even if the present technology is applied to such a field, since the liquid can be ejected toward the medium, the above-described effects can be maintained.

  In the above-described embodiment, a color inkjet printer has been described as an example of a printing apparatus. However, the present invention is not limited to this, and can be applied to, for example, a monochrome inkjet printer.

  In the above embodiment, ink has been described as an example of a liquid, but the present invention is not limited to this. For example, a liquid (including water) containing a metal material, an organic material (particularly a polymer material), a magnetic material, a conductive material, a wiring material, a film forming material, a processing solution, a gene solution, or the like may be discharged from a nozzle. .

In the above embodiment, when the distance between the end position detected in the Nth detection operation and the end position detected in the (N-1) th detection operation exceeds a predetermined value, Although at least one of the start position and the end position is determined based on the end position detected in the (N-1) th detection operation, the present invention is not limited to this. For example, when the distance between the end position detected in the Nth detection operation and the end position detected in the N-2th detection operation exceeds a predetermined value, the N-2th detection operation is performed. It is also possible to determine at least one of the start position and the end position based on the position of the edge detected in step.
However, the above-described embodiment is more preferable in that at least one of the start position and the end position can be determined more appropriately.

In the above embodiment, printing is performed on the entire surface of the printing paper P, that is, so-called borderless printing is performed. However, the present invention is not limited to this. Although not the entire surface, the above means exerts an effective effect when printing over a wide range.
However, in the case of borderless printing, since the printing is performed also on the edge of the printing paper, the merit by the above means becomes larger.

In the above embodiment, the reflective optical sensor receives a light emitting unit for emitting light and the light moving in the main scanning direction in accordance with the movement of the light emitting means in the main scanning direction. And detecting the position of the end based on a change in the output value of the light receiving unit caused by the light emitted by the light emitting unit moving in the main scanning direction blocking the end. However, the present invention is not limited to this.
However, the above embodiment is more preferable in that the position of the end can be detected more easily by doing in this way.

In the above embodiment, the light emitted from the light emitting unit moving in the main scanning direction is positioned in the main scanning direction based on the change in the output value of the light receiving unit caused by blocking the end. Are detected in the detection operation, the start position is changed according to one of the two detected positions, and the two detected ends are detected. The end position is changed according to the other of the positions, but the present invention is not limited to this. For example, the position of one end is detected in the detection operation based on a change in the output value of the light receiving unit due to light emitted from the light emitting unit moving in the main scanning direction blocking the end. The start position or the end position may be changed according to the detected position of the one end.
However, in this way, the above-described effect, that is, the effect that it is possible to avoid the generation of a margin in the printing paper by mistake, can be exhibited more significantly. This form is more desirable.

In the above embodiment, the reflective optical sensor is provided on the movable carriage provided with the print head. However, the present invention is not limited to this. For example, the carriage and the reflective optical sensor may be configured to be movable separately.
However, the above embodiment is more preferable in that the moving mechanism of the carriage and the reflection type optical sensor can be made common by doing in this way.

Further, in the above embodiment, the output value of the light receiving unit is that light emitted from the light emitting unit moving in the main scanning direction while moving the carriage in the main scanning direction blocks the edge of the printing paper. While the position of the edge is detected based on the change in the ink and ink is ejected from the print head onto the printing paper, the present invention is not limited to this. For example, the detection operation and the discharge operation may be performed separately.
However, the above embodiment is more preferable in that an efficient operation can be realized by doing in this way.

In the above embodiment, the print head includes a plurality of nozzles, and the reflective optical sensor includes a nozzle located on the most upstream side in the feed direction among the plurality of nozzles, and a main scanning direction. However, the present invention is not limited to this. For example, the reflective optical sensor may be provided side by side in the main scanning direction with a nozzle other than the nozzle located on the most upstream side in the feed direction among the plurality of nozzles.
However, when the reflective optical sensor is provided side by side in the main scanning direction with the nozzle located on the most upstream side in the feed direction, for example, the nozzle located on the most upstream side in the feed direction Compared with the case where the nozzles other than the nozzles are provided side by side in the main scanning direction, there is a higher possibility that a margin is erroneously generated on the printing paper. Therefore, the above-described embodiment is more preferable in that the above-described effect, that is, the effect of not causing a margin to be erroneously generated on the printing paper is more effectively exhibited.

In addition, when the position of the edge of the printing paper is not detected in the detection operation, liquid is not discharged from the nozzles located upstream in the feeding direction of the printing paper among the plurality of nozzles of the printing head. It is good to do.
When the printing paper feeding operation and ink ejection operation are repeatedly executed to print on the printing paper, the position of the edge of the printing paper is not detected immediately before the end of printing, and a part of the nozzles are printed on the printing paper. The state which does not oppose to arises. In such a state, if ink is ejected from a nozzle that does not face the printing paper, the ink is wasted.
In this way, a printer that reduces the ink consumption can be realized.

=== Configuration of Computer System etc. ===
Next, an embodiment of a computer system which is an example of an embodiment according to the present invention will be described with reference to the drawings.
FIG. 14 is an explanatory diagram showing an external configuration of the computer system. The computer system 1000 includes a computer main body 1102, a display device 1104, a printer 1106, an input device 1108, and a reading device 1110. In this embodiment, the computer main body 1102 is housed in a mini-tower type housing, but is not limited thereto. The display device 1104 is generally a CRT (Cathode Ray Tube), a plasma display, a liquid crystal display device, or the like, but is not limited thereto. As the printer 1106, the printer described above is used. In this embodiment, the input device 1108 is a keyboard 1108A and a mouse 1108B, but is not limited thereto. In this embodiment, the reading device 1110 uses a flexible disk drive device 1110A and a CD-ROM drive device 1110B. However, the reading device 1110 is not limited to this. Disk) etc. may be used.

  FIG. 15 is a block diagram showing a configuration of the computer system shown in FIG. An internal memory 1202 such as a RAM and an external memory such as a hard disk drive unit 1204 are further provided in a housing in which the computer main body 1102 is housed.

  In the above description, the printer 1106 is connected to the computer main body 1102, the display device 1104, the input device 1108, and the reading device 1110 to configure the computer system. However, the present invention is not limited to this. Absent. For example, the computer system may include a computer main body 1102 and a printer 1106, and the computer system may not include any of the display device 1104, the input device 1108, and the reading device 1110.

  Further, for example, the printer 1106 may have a part of each function or mechanism of the computer main body 1102, the display device 1104, the input device 1108, and the reading device 1110. As an example, the printer 1106 includes an image processing unit that performs image processing, a display unit that performs various displays, a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. It is good also as a structure to have.

  The computer system realized in this way is a system superior to the conventional system as a whole system.

  According to the present invention, it is possible to realize a liquid ejecting apparatus and a computer system that do not cause a blank in a medium.

  11 Linear encoder, 12 Linear encoder code plate, 13 Rotary encoder, 14 Rotary encoder code plate, 20 Color inkjet printer, 21 CRT, 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 Traction 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 scanning drive circuit, 62 Sub-scanning drive circuit, 63 Head drive circuit, 65 Reflective optical sensor control circuit, 66 Electrical signal measurement unit, 90 computer, 91 Video dry , 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, 1000 computer system, 1102 computer main body, 1104 display device 1106 printer, 1108 input device, 1108A keyboard, 1108B mouse, 1110 reader, 1110A flexible disk drive device, 1110B CD-ROM drive device, 1202 internal memory, 1204 hard disk drive unit.

Claims (12)

A first movement in the main scanning direction, a second movement in the main scanning direction, the second movement after the first movement, and a third movement in the main scanning direction. A moving member that performs the third movement after the second movement;
The dispensing head provided in the moving member, said discharge head for discharging liquid,
A detecting means provided in the moving member, and the detecting means for detecting the position of the edge of the medium,
The medium is fed at least once in the sub-scanning direction between the first movement and the second movement, and the medium is moved in the sub-scanning direction between the second movement and the third movement. A feed mechanism for sending at least once ;
Have
The detecting means detects, in the first movement, an end position on at least one of two end positions different from each other in the main scanning direction, which is the position of the end of the medium.
The detection means detects the position of the end on the one side in the second movement,
In the ejection head, a distance between the position of the one end detected in the first movement and the position of the one end detected in the second movement is smaller than a predetermined value. In the case, the liquid is discharged in the third movement to a position corresponding to the position of the end on the one side detected in the second movement ,
In the ejection head, a distance between the position of the one end detected in the first movement and the position of the one end detected in the second movement is larger than a predetermined value. In the case, the liquid is ejected in the third movement to a position corresponding to the position of the end on the one side detected in the first movement.
Liquid ejection device. A first movement in the main scanning direction, a second movement in the main scanning direction, the second movement after the first movement, and a third movement in the main scanning direction. A moving member that performs the third movement after the second movement;
An ejection head provided in the moving member, the ejection head for ejecting liquid;
Detection means provided in the moving member, the detection means for detecting the position of the edge of the medium;
The medium is fed at least once in the sub-scanning direction between the first movement and the second movement, and the medium is moved in the sub-scanning direction between the second movement and the third movement. A feed mechanism for sending at least once;
Have
The medium is a rectangular medium,
In the ejection head, the position of the end of the medium detected in the first movement is the position of the end of the long side of the medium, and the position of the end of the medium detected in the second movement is When the position of the edge of the long side of the medium is, the liquid is discharged in the third movement to a position corresponding to the position of the edge of the long side of the medium detected in the second movement. ,
In the ejection head, the position of the end of the medium detected in the first movement is the position of the end of the long side of the medium, and the position of the end of the medium detected in the second movement is The liquid is discharged in the third movement at a position corresponding to the position of the long edge of the medium detected in the first movement when the position is at the edge of the short side of the medium. ,
Liquid ejection device. A first movement in the main scanning direction, a second movement in the main scanning direction, the second movement after the first movement, and a third movement in the main scanning direction. A moving member that performs the third movement after the second movement;
An ejection head provided in the moving member, the ejection head for ejecting liquid;
Detection means provided in the moving member, the detection means for detecting the position of the edge of the medium;
The medium is fed at least once in the sub-scanning direction between the first movement and the second movement, and the medium is moved in the sub-scanning direction between the second movement and the third movement. A feed mechanism for sending at least once;
Have
The medium is a rectangular medium,
In the ejection head, the position of the edge of the medium detected in the first movement is the position of the side edge of the medium, and the position of the edge of the medium detected in the second movement is the position of the medium. When the position of the side edge of the medium, the liquid is discharged in the third movement to a position corresponding to the position of the side edge of the medium detected in the second movement,
In the ejection head, the position of the edge of the medium detected in the first movement is the position of the side edge of the medium, and the position of the edge of the medium detected in the second movement is the position of the medium. Discharging the liquid in the third movement to a position corresponding to the position of the side edge of the medium detected in the first movement when the position is at the lower end of the medium;
Liquid ejection device. A liquid ejection apparatus according to any one of claims 1 to 3,
The liquid ejection apparatus, wherein the ejection head ejects the liquid in the second movement. A moving member for repeatedly moving in the main scanning direction
An ejection head provided in the moving member, the ejection head for ejecting liquid;
Detection means for detecting the position of at least one of the positions of the two ends of the medium that are different from each other in the main scanning direction, and is provided in the moving member. The detection means;
A feeding mechanism for repeatedly feeding the medium in the sub scanning direction;
Have
The ejection head includes a position of the end on the one side detected in the Nth detection operation (N ≠ 1) and a position of the end on the one side detected in the N−1th detection operation. When the distance is smaller than a predetermined value, the liquid is ejected to a position corresponding to the position of the end on the one side detected in the N-th detection operation,
The ejection head has a distance between the position of the one end detected in the Nth detection operation and the position of the one end detected in the N-1th detection operation. When larger than a predetermined value, the liquid is ejected to a position corresponding to the position of the end on the one side detected in the N-1th detection operation;
Liquid ejection device. A moving member that repeatedly moves in the main scanning direction;
An ejection head provided in the moving member, the ejection head for ejecting liquid;
Detection means provided in the moving member, the detection means for detecting the position of the edge of the medium;
A feeding mechanism for repeatedly feeding the medium in the sub scanning direction;
Have
The medium is a rectangular medium,
In the ejection head, the position of the end of the medium detected in the N-1th (N ≠ 1) detection operation is the position of the end of the long side of the medium, and is detected in the Nth detection operation. When the position of the end of the medium is the position of the end of the long side of the medium, the liquid is placed at a position corresponding to the position of the end of the long side of the medium detected in the N-th detection operation. Discharge,
In the ejection head, the position of the end of the medium detected in the N-1th detection operation is the position of the end of the long side of the medium, and the position of the medium detected in the Nth detection operation is When the end position is the position of the end of the short side of the medium, the liquid is ejected to a position corresponding to the position of the end of the long side of the medium detected in the N-1th detection operation. To
Liquid ejection device. A moving member that repeatedly moves in the main scanning direction;
An ejection head provided in the moving member, the ejection head for ejecting liquid;
Detection means provided in the moving member, the detection means for detecting the position of the edge of the medium;
A feeding mechanism for repeatedly feeding the medium in the sub scanning direction;
Have
The medium is a rectangular medium,
In the ejection head, the position of the edge of the medium detected in the N-1th (N ≠ 1) detection operation is the position of the side edge of the medium, and the medium is detected in the Nth detection operation. When the position of the edge of the medium is the position of the side edge of the medium, the liquid is discharged to a position corresponding to the position of the side edge of the medium detected in the Nth detection operation,
In the ejection head, the position of the edge of the medium detected in the N-1th detection operation is the position of the side edge of the medium, and the position of the edge of the medium detected in the Nth detection operation is When the position is the position of the lower end of the medium, the liquid is discharged to a position corresponding to the position of the side end of the medium detected in the N-1th detection operation.
Liquid ejection device. A liquid ejection apparatus according to any one of claims 5 to 7,
The liquid discharge apparatus, wherein the discharge head discharges the liquid in a movement in which the detection unit performs the N-1th detection operation. A liquid ejection device according to any one of claims 1 to 8,
The detection means includes a light receiving sensor,
The ejection head has a plurality of nozzles along the sub-scanning direction,
The medium is conveyed from the upstream side in the sub-scanning direction to the downstream side in the sub-scanning direction,
The plurality of nozzles includes a nozzle located on the downstream side of the light receiving sensor in the sub-scanning direction,
The ejection head ejects the liquid from a nozzle located on the downstream side of the light receiving sensor in the sub-scanning direction;
Liquid ejection device. The liquid ejection apparatus according to any one of claims 1 to 9 ,
A liquid ejecting apparatus for ejecting liquid on the entire surface of the medium. The liquid ejection device according to any one of claims 1 to 10,
A start position at which the liquid is discharged by the discharge head that moves in the main scanning direction, and the start position in the main scanning direction changes according to the position of the edge of the medium detected by the detection unit. To
Liquid ejection device. A liquid ejection apparatus according to any one of claims 1 to 11,
A computer main body connectable to the liquid ejection device;
A display device connectable to the computer body;
A computer system.

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