JP2004174780A - Ink jet recording apparatus, program and recording medium - Google Patents

Abstract

Provided is an ink jet recording apparatus capable of avoiding a problem when the inside of the apparatus is contaminated by ejecting ink droplets without consuming unnecessary ink even in printing in a main scanning direction.
An ink jet recording apparatus performs main scanning of a printable recording head and sub-scans a recording medium to perform predetermined printing on a storage medium. By changing the speed according to the type of recording medium set by the operator, the range of the recording medium in the main scanning direction is detected, and if the detected position of the recording head is out of the range of the recording medium, printing is not performed. did.
[Selection] Fig. 10

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention performs the functions of an ink jet recording apparatus that performs reciprocating movement of a carriage on which an ink jet recording head is mounted as a recording head in the recording width direction of a sheet to form dots on the sheet to perform printing, and an ink jet recording apparatus. And a computer-readable recording medium on which the program is recorded.
[0002]
[Prior art]
2. Description of the Related Art In recent years, ink jet printers that eject ink from nozzles of a recording head have become widespread as output devices of computers.
In this inkjet printer, paper is supported on a platen so as to face the recording head, and ink droplets are ejected from nozzles on the recording head at predetermined positions on the paper while moving the recording head in the horizontal direction (main scanning direction). When the main scanning is completed, a predetermined amount of paper is conveyed in the vertical direction (sub-scanning direction), and the main scanning and the sub-scanning are alternately repeated to perform predetermined printing.
[0003]
[Patent Document 1]
JP-A-2002-103587
[0004]
[Problems to be solved by the invention]
However, in the above-described ink jet printer, ink droplets may land on a transport belt or a platen without landing on paper.
In such a case, the ink that has landed on the transport belt or the platen will stain the paper that subsequently passes. In addition, unnecessary ink is ejected and wasteful ink is consumed.
[0005]
According to the technique disclosed in Patent Document 1, when printing is performed up to the edge of the printing paper using a print head including a plurality of nozzles, printing can be performed without margins without staining the platen. For this purpose, an extended area wider than the printing paper determined based on the type of printing paper is set, and for printing in the sub-scanning direction, ink droplets are ejected using only nozzles of the head on the printing paper. Dots are recorded.
In addition, since the nozzles that print the left and right edges of the printing paper in the main scanning direction are located on the left groove or the right groove, even if the ink drops come off the printing paper, the ink drops land on the center of the platen. Since the ink droplet lands on the left groove portion or the right groove portion without performing, the printing paper is not stained by the ink droplets.
[0006]
However, in the technique of Patent Document 1, in the printing in the main scanning direction, ink is ejected at a position off the printing paper, so that the ink is wasted.
[0007]
An object of the present invention is to provide an ink jet recording apparatus, a program, and a recording medium that can avoid a problem when an ink droplet is ejected to contaminate the inside of the apparatus without consuming unnecessary ink even in printing in the main scanning direction. I do.
Still another object of the present invention is to provide an ink jet recording apparatus, a program, and a recording medium that detect a range of a sheet only in the first main scan and minimize a decrease in productivity due to a detection operation.
Another object of the present invention is to provide an ink jet recording apparatus, a program, and a recording medium for detecting an edge of a sheet by slowing a main scanning speed when detecting a range of the sheet and minimizing an error.
Another object of the present invention is to provide an ink jet recording apparatus, a program, and a recording medium for detecting a range of a sheet, by changing a main scanning speed according to a type of the sheet so as to more accurately detect an end position. provide.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, claim 1 of the present invention is an ink jet recording apparatus that performs predetermined printing on a storage medium by causing a printable recording head to perform main scanning and sub-scanning a recording medium, Means for detecting the range of the print medium in the main scanning direction, means for detecting the position of the print head, and means for determining whether the detected position of the print head is out of the range of the print medium. And printing is not performed when the detected position of the recording head is outside the range of the recording medium.
According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the means for detecting the range of the recording medium in the main scanning direction includes a main scanning speed only for the first main scanning on the recording medium. Is detected later.
According to a third aspect of the present invention, in the ink jet recording apparatus according to the first or second aspect, the means for detecting the range of the recording medium in the main scanning direction comprises: It is characterized in that the detection is changed depending on the type of the recording medium set by the operator.
According to a fourth aspect of the present invention, there is provided a program for causing a computer to execute the functions of the inkjet recording apparatus according to the first, second, or third aspect.
According to a fifth aspect of the present invention, there is provided a computer-readable recording medium storing the program according to the fourth aspect.
[0009]
According to the above configuration, by detecting the sheet width for each sheet, printing is performed within the sheet width, so that useless ink ejection is reduced and ink waste can be suppressed. Thereby, it is possible to prevent the ink from being contaminated by ejecting the ink into the apparatus such as the electrostatic transport belt, and to prevent the malfunction of the apparatus caused by unnecessary ejection.
[0010]
Further, since the range of the sheet is detected only by the first main scanning, and the range is referred to in the subsequent main scanning, the productivity of the entire printing operation can be improved.
Further, since the range is detected for each sheet, even if sheets having different widths are included when a plurality of sheets are continuously printed, the width can be detected.
[0011]
In addition, since the speed is reduced only in the first main scanning of the sheet, there is no error in the detection position, and the sheet width can be detected more accurately.
[0012]
Further, since the speed of the first main scan on the paper is changed according to the type of paper set by the operator, the range of the paper can be detected more accurately regardless of the type of paper.
Conversely, on paper whose edge is easy to detect, it can be detected at a speed equal to or close to the normal main scanning speed, increasing the productivity of the entire printing operation and detecting the range of the paper more accurately. can do.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view of a print control mechanism of an ink jet recording apparatus according to the present invention, and FIG. 2 is a side view of the print control mechanism.
This ink jet recording apparatus includes a carriage 13 movable in the main scanning direction inside the recording apparatus main body 1, a recording head 14 including an ink jet head mounted on the carriage 13, an ink tank 15 for supplying ink to the recording head 14, and the like. A paper feed cassette (or a paper feed tray) 4 capable of loading a large number of sheets of paper (recording medium) 3 from the front side in a lower portion of the recording apparatus main body 1. Can be freely inserted and removed. In the following description, “paper” refers not only to paper used in a general printing apparatus, but also to a wide range such as cloth, plastic film, and metal plate that can accept ink ejected by a recording head. Shall be.
In addition, the manual tray 5 for manually feeding the paper 3 can be opened, and the paper 3 fed from the paper feed cassette 4 or the manual tray 5 is taken in. Is recorded, and the paper is discharged to the paper discharge tray 6 mounted on the rear side.
[0014]
The print control mechanism 2 holds a carriage 13 slidably in a main scanning direction (a direction perpendicular to the paper surface of FIG. 2) by a main guide rod 11 which is a guide member which is laterally mounted on left and right side plates (not shown). Is mounted with a recording head 14 composed of an inkjet head for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) with the ink droplet ejection direction facing downward, and a carriage. Above 13, each sub-tank 12 for supplying each color ink to the recording head 14 is mounted.
The sub-tank 12 corresponding to each color ink is connected via an ink supply tube 16 to an ink tank 15 which is mounted so as to be exchangeable, and the ink of the corresponding color is supplied from the ink tank 15.
[0015]
The carriage 13 is slidably fitted on the main guide rod 11 on the rear side (downstream side in the sheet conveying direction). In order to move and scan the carriage 13 in the main scanning direction, a timing belt 20 is stretched between a driving pulley 18 and a driven pulley 19 that are driven to rotate by a main scanning motor 17. It is fixed to.
[0016]
The ink jet head used as the recording head 14 presses ink through a vibration plate that forms a wall of a liquid chamber (ink flow path) using an electromechanical transducer such as a piezoelectric element.
This inkjet head includes a piezo type, a bubble type in which bubbles are generated by film boiling by a heating resistor, and pressurizes ink, or a diaphragm forming an ink flow path wall surface and an electrode opposed thereto. An electrostatic type in which the diaphragm is displaced by the electrostatic force during this period to pressurize the ink can be used, but here, an electrostatic type ink jet head is used.
[0017]
Although the recording heads 14 corresponding to each color are used here as recording heads, a single head having a nozzle for ejecting ink droplets of each color may be used.
[0018]
On the other hand, in order to transport the paper 3 set in the paper feed cassette 4 to the lower side of the recording head 14, the paper feed roller 21 and the friction pad 22, which separate and feed the paper 3 from the paper feed cassette 4, and guide the paper 3 Guide member 23, a transport roller 24 that reverses and transports the fed paper 3, a transport roller 25 that is pressed against the peripheral surface of the transport roller 24, and a feed angle of the paper 3 from the transport roller 24. A tip roller 26 is provided. The transport roller 24 is driven to rotate by a sub-scanning motor 27 via a gear train.
[0019]
Further, an electrostatic transport belt 29 is provided to guide the sheet 3 sent from the transport roller 24 to the lower side of the recording head 14 in accordance with the moving range of the carriage 13 in the main scanning direction. The electrostatic transport belt 29 plays a role of adsorbing the transported paper 3 by being charged by the charger 30 and keeping the paper surface and the head surface parallel. On the downstream side of the electrostatic transport belt 29 in the paper transport direction, a paper discharge roller 33 that sends out the paper 3 to the paper discharge tray 6 is provided.
[0020]
A reliability maintenance / recovery mechanism (hereinafter, referred to as a subsystem) 37 for maintaining and recovering the reliability of the recording head 14 is disposed on the right end side in the moving direction of the carriage 13. The carriage 13 is moved to the subsystem 37 side during printing standby, and the recording head 14 is capped by capping means or the like.
In addition, when the sub-system 37 is located at the position on the subsystem 37 side (this position is referred to as a reliability maintenance recovery position), control is performed to generate meniscus vibration as part of the reliability maintenance recovery operation using the second drive waveform.
[0021]
Next, the operation related to the detection of the edge position of the sheet and the image mask will be described.
FIG. 3 is a front view of a print control mechanism of the ink jet recording apparatus. Two print heads (101, 102) are mounted on the carriage 13, and two nozzle rows (105) are further mounted on the print head 101. , 106) and the print head 102, two nozzle rows (103, 104) are arranged, and ink droplets are ejected from each of the nozzle rows.
[0022]
When the carriage 13 is at the capping position as shown in FIG. 3, the recording head 101 is covered with the cap 107, and the recording head 102 is covered with the suction / cap 108, which keeps the head surface moist and causes clogging of ink in the nozzle row. Protected to be difficult.
[0023]
The sheet detection sensor 109 is installed on the left side when viewed from the front of the carriage 13, has a light emitting unit and a light receiving unit, and detects the presence or absence of a sheet from light reflection.
FIG. 4 shows the mechanism of the sheet detection sensor 109. Light emitted from a light emitting unit (light emitting element) 301 is reflected on the sheet 3 on the electrostatic transport belt 29, and a light receiving unit (light receiving element) 302 To receive light.
As shown in FIG. 5, when the light emitted from the light emitting unit 301 is applied to the electrostatic transport belt 29 coated with a dark color, the light receiving unit 302 cannot obtain reflected light. Judge that there is no paper.
Therefore, the sheet detection sensor 109 can detect the presence or absence of a sheet based on the presence or absence of sensitivity at the light receiving unit 302.
[0024]
For example, FIG. 6 is a diagram in which the carriage 13 has moved in the main scanning positive direction from the capping position. At this carriage position, the paper detection sensor 109 does not detect the paper 3. However, at the position in FIG. 7 where the carriage 13 has further advanced in the main scanning positive direction (left direction in FIG. 6), the right end of the sheet 3 is detected, and further in the main scanning positive direction (left direction in FIG. 8). , The left end of the sheet 3 is detected, and the sheet 3 is not detected at a position further advanced in the main scanning positive direction (the left direction in FIG. 8).
[0025]
FIG. 9 illustrates the distance between the sheet detection sensor and each nozzle row, where S is the center position between the light emitting unit 301 and the light receiving unit 302.
S1 is the distance from the position of S to the nozzle row 106,
S2 is the distance from the position of S to the nozzle row 105,
S3 is the distance from the position of S to the nozzle row 104,
S4 is the distance from the position of S to the nozzle row 103
Are respectively shown.
[0026]
FIG. 10 is a control block diagram of the print control mechanism unit 2 of the ink jet recording apparatus. In FIG. 10, the CPU 500 controls each unit of the print control mechanism unit 2 by giving a command. When a command is given to the sub-scanning motor operation command circuit 509 and the paper feed clutch driver 511, the sub-scanning motor 27 and the paper feed clutch 512 are driven to feed the paper 3 from the paper feed cassette 4 (see FIG. 2). Carry out transportation.
[0027]
Further, when a command is given to the main scanning motor operation command circuit 506, the main scanning motor 17 is driven via the main scanning motor driver 507 to move the carriage 13 in the main scanning direction. At this time, the CPU 500 can know the position of the carriage 13 by reading the output signal of the main scanning encoder 513 via the main scanning motor operation command circuit 506.
[0028]
The operation unit 503 includes an LCD, an LED, and the like (not shown), and notifies an operator of a state of the apparatus according to a command from the CPU 500.
The nonvolatile memory 501 is a memory that can hold written data even when the power is turned off, and is configured by, for example, an SRAM or an E2PROM with a built-in battery.
[0029]
The image memory 502 is a memory in which image data to be printed is stored, and is configured by, for example, an SDRAM.
The image data read from the image memory 502 is expanded from the compressed state by the expansion circuit 520, and the image mask circuit 521 determines a mask as to which nozzle row the ink droplet is to be ejected. The ink is sent to the recording head 14 via the circuit 522, and ejects ink droplets from a nozzle row that is not masked.
Here, the expansion circuits 520, the image mask circuits 521, and the I / F circuits 522 are prepared by the number of nozzle rows, and process data of each nozzle row in parallel.
[0030]
Also, an output signal of the main scanning encoder 513 is input to the I / F circuit 522, and image data is sent to the recording head in synchronization with the main scanning position of the carriage 13.
Further, the CPU 500 can mask an output image at an arbitrary timing by giving a command to the image mask circuit 521.
The output signal of the sheet detection sensor 109 is input to the CPU 500.
[0031]
Next, an operation of detecting a sheet edge will be described with reference to the flowchart of FIG.
When the printing operation is started, the CPU 500 feeds and conveys the sheet 3 onto the electrostatic conveyance belt 29 (step S1). After the conveyance operation is completed (YES in step S2), the CPU 500 sets the carriage position P to the origin (step S1). S3) The driving of the carriage 13 is started, and the carriage 13 is moved in the main scanning positive direction (step S4).
[0032]
At this time, if it is the first main scan for the sheet (YES in step S5), the carriage position P at the timing when the output of the sheet detection sensor 109 changes from OFF to ON is read, and the position P is set to the right end coordinate position of the sheet. It is stored as Pr (steps S6, S7, S8).
Further, the carriage position P at the timing when the output of the sheet detection sensor 109 changes from ON to OFF is read, and the position P is stored as the left end position Pl of the sheet (steps S9 and S10).
[0033]
After detecting the left and right end positions of the sheet, the carriage 13 is driven in the negative direction of the main scanning and returned to the capping position, and then the sheet end position detection operation is completed (steps S11 and S12).
On the other hand, if the carriage is not the first main scan of the sheet in step S5 (NO in step S5), the sheet edge detecting operation is not performed.
[0034]
The operation of detecting the sheet edge described above can be performed simultaneously with the operation of printing.
In the case of printing a plurality of sheets continuously, an operation of detecting a sheet edge is performed for each sheet.
[0035]
As described above, the range of the sheet is detected only by the first main scan on the sheet, the range of the sheet is maintained, and the information is referred to in the subsequent main scans, so that the productivity of the entire printing operation can be increased. it can.
In addition, by detecting the range for each sheet, even if sheets of different widths are included in continuous printing of a plurality of sheets, the difference in the width can be detected.
[0036]
Next, another sheet edge detection operation will be described with reference to the flowchart of FIG.
According to this method, in the case of the first main scan on the sheet, the main scan speed of the carriage 13 is made lower than the normal main scan speed, and the sheet end detection operation is not performed from the next main scan, and the main scan speed of the carriage is reduced. The speed was returned to the normal main scanning speed.
In this way, by reducing the speed of only the first main scan on the sheet, there is no error in the detection position that may occur at the normal main scan speed, and the range of the sheet can be detected more accurately. .
[0037]
When the printing operation is started, the CPU 500 feeds and conveys the sheet 3 onto the electrostatic conveyance belt 29 (step S21), and after the conveyance operation is completed (YES in step S22), sets the carriage position P to the origin (step S21). S23), driving of the carriage 13 is started, and the carriage 13 is moved in the main scanning positive direction (step S24).
[0038]
At this time, if it is the first main scan for the sheet (YES in step S25), the carriage 13 is moved at a speed lower than the normal driving speed, and the carriage 13 is moved at the timing when the output of the sheet detection sensor 109 changes from OFF to ON. The position P is read out and stored as the right end coordinate position Pr of the sheet (steps S26, S27, S28, S29).
Further, the carriage position P at the timing when the output of the sheet detection sensor 109 changes from ON to OFF is read, and the position P is stored as the left end position Pl of the sheet (steps S30 and S31).
[0039]
After detecting the left and right end positions of the sheet, the carriage 13 is driven in the negative direction of the main scanning, and after returning to the capping position, the driving speed is returned to a normal speed to detect the sheet end position. It is completed (steps S32, S33, S34).
On the other hand, if the carriage is not the first main scan on the sheet in step S25 (NO in step S25), the sheet edge detection operation is not performed.
[0040]
The operation of detecting the sheet edge described above can be performed simultaneously with the operation of printing.
In the case of printing a plurality of sheets continuously, an operation of detecting a sheet edge is performed for each sheet.
[0041]
Further, another sheet edge detection operation will be described with reference to the flowchart of FIG.
In this method, an operator sets which type of paper is to be printed before printing, and records the content in a nonvolatile memory 501. The main scanning speed of the carriage is determined by referring to the data during the first main scanning of the carriage driving. This is because, since the reflectance varies depending on the type of paper, the main scanning speed is changed in accordance with the type of paper, and the paper detection sensor 109 detects the edge of the paper more reliably.
[0042]
This makes it possible to more accurately detect the range of the sheet regardless of the type of sheet.
Conversely, on paper whose edge is easy to detect, it can be detected at a speed equal to or close to the normal main scanning speed, increasing the productivity of the entire printing operation and detecting the range of the paper more accurately. can do.
[0043]
When the printing operation is started, the CPU 500 first reads out which type of paper is to be printed from the nonvolatile memory 501 (step S41), and feeds and transports the paper 3 onto the electrostatic transport belt 29 (step S42). After completion of the transport operation (YES in step S43), the position P of the carriage is set to the origin (step S44), the driving of the carriage 13 is started, and the carriage 13 is moved in the main scanning positive direction (step S45). .
[0044]
At this time, if it is the first main scan for the sheet (YES in step S46), the drive speed of the carriage 13 is determined and moved based on the type of the previously read sheet, and the output of the sheet detection sensor 109 is changed from OFF to ON. The carriage position P at the changed timing is read, and the position P is stored as the right end coordinate position Pr of the sheet (steps S47, S48, S49, S50).
Further, the carriage position P at the timing when the output of the sheet detection sensor 109 changes from ON to OFF is read, and the position P is stored as the left end position Pl of the sheet (steps S51 and S52).
[0045]
After detecting the left and right end positions of the sheet, the carriage 13 is driven in the negative direction of the main scanning, and after returning to the capping position, the driving speed is returned to a normal speed to detect the sheet end position. It is completed (steps S53, S54, S55).
On the other hand, if the carriage is not the first main scan for the sheet in step S46 (NO in step S46), the sheet edge detecting operation is not performed.
[0046]
The operation of detecting the sheet edge described above can be performed simultaneously with the operation of printing.
In the case of printing a plurality of sheets continuously, an operation of detecting a sheet edge is performed for each sheet.
[0047]
Next, an image mask operation in the image mask circuit 521 will be described.
As described above, the central position between the light emitting unit 301 and the light receiving unit 302 of the sheet detection sensor 109 is S,
S1 = distance from the position of S to the nozzle row 106,
S2 = distance from the position of S to the nozzle row 105;
S3 = distance from the position of S to the nozzle row 104;
S4 = distance from position S to nozzle row 103
From these coordinates, the mask release start coordinates and end coordinates of each nozzle row are calculated as follows, and are recorded in the nonvolatile memory 501. Here, “unmasking” refers to a state in which ink droplets are ejected from the nozzle row.
[0048]
Mask release start coordinates Ps1 = Pr + S1 of nozzle array 106
Mask release start coordinates Ps2 = Pr + S2 of the nozzle array 105
Mask release start coordinates Ps3 = Pr + S3 of the nozzle array 104
Mask release start coordinates Ps4 = Pr + S4 of the nozzle array 103
Unmasking end coordinates Pe1 = Pl + S1 of the nozzle array 106
Unmasking end coordinates Pe2 = Pl + S2 of the nozzle array 105
Uncoupling end coordinates Pe3 = Pl + S3 of the nozzle array 104
Mask release end coordinates Pe4 = Pl + S4 of the nozzle array 103
[0049]
When the printing operation is started, the CPU 500 feeds and conveys the sheet 3 onto the electrostatic conveyance belt 29. After the conveyance operation is completed, after enabling the image masks of all the nozzle rows (103, 104, 105, and 106), The driving of the carriage 13 is started, and the carriage 13 is moved in the main scanning positive direction.
[0050]
Next, the CPU 500 reads the image data from the image memory 502, expands the compressed data from the compressed state by the expansion circuit 520 corresponding to each nozzle row, and further sets a mask indicating which nozzle row should eject the ink droplets. The image data is determined by the mask circuit 521 and sent to the recording head 14 via the I / F circuit 522, and ink droplets are ejected from an unmasked (released) nozzle row.
[0051]
FIG. 14 is a flowchart for explaining an image masking operation of the image masking circuit 521 for one nozzle row 103. The image masking operation for the nozzle array 103 will be described, but the other nozzle arrays (104, 105, 106) operate in the same manner based on the corresponding release start coordinates and release end coordinates.
[0052]
The image mask for the nozzle array 103 is made effective (step S60).
When the coordinate position P of the carriage 13 has reached Ps4 from the output signal of the main scanning encoder 513 (YES in step S61), the image mask of the nozzle array 103 is released (step S62). On the other hand, when the coordinate position P does not reach Ps4 (NO in step S61), the image mask of the nozzle row 103 remains valid.
[0053]
Next, when the coordinate position P of the carriage 13 has reached Pe4 (YES in step S63), the image mask of the nozzle row 103 is returned to valid (step S64). On the other hand, if the coordinate position P has not reached Pe4 (NO in step S63), the image mask of the nozzle array 103 is released.
[0054]
When the mask is determined in this manner, in the section from the start to the end of the image mask release of each nozzle row, the image data given to the head is ejected from the nozzle row as an effective image. Conversely, in a section where the mask of each nozzle row is not released, white data is given to the head, and ink is not ejected from the nozzle row.
[0055]
In the above-described method, the CPU 500 controls the image mask circuit 521 in real time while monitoring the carriage position. However, the mask release start determination circuit 550 having the same configuration as the mask release start determination circuit 550 shown in FIG. , The processing load on the CPU can be reduced.
[0056]
Since the mask release start determination circuit 550 and the mask release end determination circuit 560 are prepared in correspondence with the image mask circuit 521, they are required for each nozzle row. In the following description, the nozzle row 103 will be described, but the other nozzle rows (104, 105, and 106) operate similarly.
[0057]
The mask release start determination circuit 550 includes a main scanning counter 551, a register 552, and a comparator 553.
The register 552 stores the mask release start position Ps4 of the nozzle array 103 described above.
The main scanning counter 551 measures the carriage position from the input main scanning encoder signal and outputs the same to the comparator 553.
The comparator 553 compares the mask release start position written in the register 552 at the timing of the CPU bus with the carriage position measured by the main scanning counter 551, and if the mask release start position Ps4 is smaller, the comparator 553 performs the process for the nozzle row 103. A mask release start signal is output to the image mask circuit 521. On the other hand, when the carriage position is smaller, a mask release end signal is output to the image mask circuit 521.
[0058]
Similarly, the mask release end determination circuit 560 includes a main scanning counter 561, a register 562, and a comparator 563.
The register 562 stores the mask release end position Pe4 of the nozzle array 103 described above.
The main scanning counter 561 measures the carriage position from the input main scanning encoder signal and outputs it to the comparator 563.
The comparator 563 compares the mask release end position Pe4 written in the register 562 at the timing of the CPU bus with the carriage position measured by the main scanning counter 561. If the mask release end position Pe4 is smaller, the nozzle row 103 Is output to the image masking circuit 521. On the other hand, when the carriage position is smaller, a mask release start signal is output to the image mask circuit 521.
[0059]
When using these determination circuits, the CPU 500 writes the mask release start position in the register 552 of the determination circuit corresponding to each nozzle row and the mask release end position in the register 562 in advance.
When the carriage 13 starts moving, the main scanning encoder signal is input to the main scanning counter 551 and the main scanning counter 561, and the carriage position is measured by the main scanning counter 551 and the main scanning counter 561. Here, when the carriage position measured by the main scanning counter 551 becomes larger than the position written in the register 552, the comparator 553 outputs a mask release start signal, and on the other hand, outputs a mask release end signal while it is smaller. This output signal is provided to the image mask circuit 521.
[0060]
On the other hand, when the carriage position measured by the main scanning counter 561 becomes larger than the position written in the register 562, a mask release end signal is output from the comparator 563. On the other hand, while it is smaller, a mask release start signal is output. This output signal is provided to the image mask circuit 521.
[0061]
When the output signals from the mask release start determination circuit 550 and the mask release end determination circuit 560 are both mask release start signals, the image mask circuit 521 interprets that the image mask has been released and outputs the image of the nozzle array 103. Release the mask. If the output signal is any other combination, the image mask is interpreted as valid and the image mask of the nozzle array 103 is valid.
[0062]
The present invention is not limited to only the above-described embodiment. Each function constituting the print control mechanism of the ink jet recording apparatus of the above-described embodiment is programmed, written in advance in a recording medium of a ROM, and the ROM is mounted on the ink jet recording apparatus, and these programs are executed by a microprocessor. It goes without saying that the object of the present invention is achieved by executing the method.
In this case, the executed state read from the recording medium realizes the function of the above-described embodiment, and the program and the recording medium on which the program is recorded also constitute the present invention.
[0063]
Note that programs for realizing such functions include semiconductor media (for example, ROM, non-volatile memory, etc.), optical media (for example, DVD, MO, MD, CD, etc.), magnetic media (for example, magnetic tape, flexible disk, etc.). , Etc.).
Alternatively, a program stored in a storage device may be directly supplied from a server computer via a communication network such as a network. In this case, the storage device of the server computer is also included in the recording medium of the present invention.
[0064]
When provided on such a recording medium, the program is read from the recording medium, installed in an internal storage device or an external storage device, and the installed program is executed by a microprocessor, whereby the functions of the above-described embodiment are performed. Is realized. Alternatively, the program recorded on the recording medium may be directly executed.
[0065]
Further, in the above embodiment, the inkjet recording apparatus has been described, but the present invention is not limited to the configuration. Any printing apparatus, such as a thermal type or a thermal transfer printing apparatus, is effective as long as printing is performed by transporting paper relative to the recording head.
[0066]
【The invention's effect】
As described above, according to the present invention, by detecting the sheet width for each sheet and performing printing within the sheet width, wasteful ink ejection is reduced, and waste of ink can be suppressed. . Thereby, it is possible to prevent the ink from being contaminated by ejecting the ink into the apparatus such as the electrostatic transport belt, and to prevent the malfunction of the apparatus caused by unnecessary ejection.
[0067]
Further, since the range of the sheet is detected only by the first main scanning, and the range is referred to in the subsequent main scanning, the productivity of the entire printing operation can be improved.
Further, since the range is detected for each sheet, even if sheets having different widths are included when a plurality of sheets are continuously printed, the width can be detected.
[0068]
In addition, since the speed is reduced only in the first main scanning of the sheet, there is no error in the detection position, and the sheet width can be detected more accurately.
[0069]
Further, since the speed of the first main scan on the paper is changed according to the type of paper set by the operator, the range of the paper can be detected more accurately regardless of the type of paper.
Conversely, on paper whose edge is easy to detect, it can be detected at a speed equal to or close to the normal main scanning speed, increasing the productivity of the entire printing operation and detecting the range of the paper more accurately. can do.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a print control mechanism of an ink jet recording apparatus.
FIG. 2 is a side view of the print control mechanism of FIG. 1;
FIG. 3 is a cross-sectional view of a print control mechanism of the inkjet recording apparatus as viewed from the front.
FIG. 4 is a diagram illustrating a state where a sheet detection sensor is detecting a sheet.
FIG. 5 is a diagram illustrating a state where a sheet detection sensor does not detect a sheet.
FIG. 6 is a diagram showing a state in which the carriage has moved in the main scanning positive direction from the capping position, but the paper detection sensor has not detected the paper at this carriage position.
FIG. 7 is a diagram illustrating a state in which the carriage further moves in the main scanning positive direction than in FIG. 6, and a sheet detection sensor detects the right end of the sheet.
FIG. 8 is a diagram illustrating a state in which the carriage has moved further in the main scanning positive direction than in FIG. 7 and a sheet detection sensor has just detected the left end of the sheet.
FIG. 9 is a diagram illustrating a distance between a sheet detection sensor and each nozzle row.
FIG. 10 is a control block diagram of a print control mechanism.
FIG. 11 is a flowchart illustrating a sheet edge position detection operation.
FIG. 12 is a flowchart illustrating another sheet edge position detection operation.
FIG. 13 is a flowchart illustrating another sheet edge position detection operation.
FIG. 14 is a flowchart illustrating an image mask operation.
FIG. 15 is a circuit diagram of a mask release start / end determination circuit of the print control mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Recording device main body, 2 ... Print control mechanism part, 3 ... Paper, 4 ... Paper feed cassette, 5 ... Manual feed tray, 6 ... Discharge tray, 11 ... Main guide rod, 12 ... Sub tank, 13 ... Carriage, 14, 101, 102: recording head, 15: ink tank, 16: ink supply tube, 17: main scanning motor, 18: drive pulley, 19: driven pulley, 20: timing belt, 21: paper feed roller, 22: friction pad, Reference numeral 23: guide member, 24: transport roller, 25: transport roller, 26: tip roller, 27: sub-scanning motor, 29: electrostatic transport belt, 30: charger, 33: discharge roller, 37: subsystem, 103, 104, 105, 106: nozzle row, 107: cap, 108: suction / cap, 109: paper detection sensor, 301: light emitting unit, 302: light receiving unit 500: CPU, 501: Non-volatile memory, 502: Image memory, 503: Operation unit, 506: Main scanning motor operation command circuit, 507: Main scanning motor driver, 509: Sub scanning motor operation command circuit, 510: Sub scanning motor Driver, 511: paper feed clutch driver, 512: paper feed clutch, 513: main scanning encoder, 520: expansion circuit, 521: image mask circuit, 522: I / F circuit, 550: mask release start determination circuit, 551: main Scan counter, 552 register, 553 comparator, 560 mask release end determination circuit, 561 main scanning counter, 562 register, 563 comparator.

Claims (5)

Means for detecting a range of a recording medium in a main scanning direction in an ink jet recording apparatus for performing predetermined printing on a storage medium by performing main scanning on a printable recording head and sub-scanning the recording medium; Means for detecting the position of the recording head, and means for determining whether the detected position of the recording head is out of the range of the recording medium, and the position of the detected recording head is outside the range of the recording medium. An ink jet recording apparatus wherein printing is not performed in some cases. 2. The ink jet recording apparatus according to claim 1, wherein the means for detecting the range of the recording medium in the main scanning direction detects only the first main scanning on the recording medium at a reduced main scanning speed. An inkjet recording apparatus characterized by the above-mentioned. 3. The ink jet recording apparatus according to claim 1, wherein the means for detecting a range of the recording medium in the main scanning direction sets an initial main scanning speed for the recording medium according to a type of the recording medium set by an operator. An ink jet recording apparatus characterized in that detection is changed. A program for causing a computer to execute the functions of the inkjet recording apparatus according to claim 1. A computer-readable recording medium on which the program according to claim 4 is recorded.

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