JP2007106126A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer which can adjust positional misalignment below one dot. <P>SOLUTION: A RAM 30 stores a positional misalignment determination pattern 31 for adjusting positional misalignment. The positional misalignment determination pattern 31 is read and recorded on recording paper by a recording unit 50. In the positional misalignment determination pattern 31 recorded on the recording paper, whether each line of cyan, magenta, or yellow is recorded so that it is misaligned by 0, ±1, ±2, ±3, ±4 with respect to one black line of a predetermined interval is determined. Based on the determination result, decay time of the trigger signals of the misaligned colors is changed in PWMt 531 to 534. In synchronization with a rise of the trigger signals, strobe signals are transmitted from PWMs 535 to 538 to LED heads 541 to 544. As a result, the timing that electrostatic latent images are formed on the photosensitive drums 561 to 564 of the misaligned colors is also changed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printer typified by a facsimile machine with a color copying function (hereinafter referred to as a multi-function machine), and more particularly to a printer characterized by adjusting a positional deviation in the sub-scanning direction.

  In recent years, with the widespread use of personal computers and the Internet, it has become common to create manuscripts in color, such as various presentations and conference materials, and output them on recording paper, while the colorization of office documents has rapidly progressed. For this reason, electrophotographic color printers are rapidly spreading in offices and the like.

  In the color printer recording system, four color photosensitive drums are connected in series to continuously record four colors (yellow (Y), magenta (M), cyan (C), and black (K)) in one process. There is a tandem method. This tandem method is characterized in that the printing process is simple and the paper feed flow line is short, so that printing can be performed at high speed.

  By the way, in a tandem color printer using LED heads, the positional deviation of the LED heads of the respective colors with respect to the recording paper conveyance direction is adjusted before shipment so that a good recorded image can be obtained. Specifically, first, the positional deviation of the LED heads of the respective colors with respect to the recording paper conveyance direction is physically adjusted, and then the timing for transferring the image data to the LED heads of the respective colors is adjusted in units of one dot.

  However, since the physical adjustment is performed manually by the operator, fine adjustment is difficult. Further, since the transfer timing can be adjusted only in units of one dot, it cannot be adjusted for a positional shift of less than one dot.

  The present invention has been made paying attention to such problems, and an object thereof is to provide a printer capable of adjusting a positional deviation of less than one dot.

  In order to achieve the above object, according to the first aspect of the present invention, there are provided a plurality of heads, a strobe signal that adjusts the time during which light is emitted from each head, and a pulse signal that adjusts the transmission timing of the strobe signal. Control means for controlling the trigger signal, and adjustment means for adjusting the pulse width of the trigger signal, the control means for the reference head in the printer that sends the strobe signal based on the end of the trigger signal When the adjustment target head is less than 1 dot and misaligned in the anti-sub-scanning direction, the adjustment means adjusts the pulse width of the trigger signal corresponding to the adjustment target head, and the trigger signal end timing Is delayed by a time obtained by multiplying the line period by the ratio of the amount of positional deviation with respect to one dot, thereby obtaining one dot in the anti-sub-scanning direction. When the head to be adjusted is less than one dot and is displaced in the sub-scanning direction with respect to the reference head, the adjustment means corresponds to the head to be adjusted. By adjusting the pulse width of the trigger signal and advancing the end timing of the trigger signal by the time obtained by multiplying the line period by the ratio of the amount of displacement with respect to 1 dot, the displacement of less than 1 dot in the sub-scanning direction is reduced. adjust.

  According to a second aspect of the present invention, in the printer according to the first aspect, the printer is an electrophotographic color printer using a tandem method, and the head has four colors of yellow, magenta, cyan, and black. Are composed of heads corresponding respectively.

  According to a third aspect of the present invention, the printer according to the second aspect further comprises storage means for storing a positional deviation determination pattern for determining the positional deviation, and the positional deviation determination pattern is predetermined at predetermined intervals. Using one black line having a length and one central line in the sub-scanning direction of black as a reference line, the positional deviation with respect to one black line at a predetermined interval is increased by one line in the sub-scanning direction and the counter-sub-scanning direction. Each line of cyan, magenta and yellow.

  According to a fourth aspect of the present invention, in the printer according to the third aspect, the operation means for reading the positional deviation determination pattern from the storage means and recording the read positional deviation determination pattern on a recording sheet. Equipped with.

  According to the present invention, it is possible to adjust a positional shift of less than one dot.

An embodiment in which a printer according to the present invention is embodied in a multifunction machine will be described below with reference to the drawings.
As shown in FIG. 1, the multi-function device 1 includes an MPU 10, a ROM 20, a RAM 30, a reading unit 40, a recording unit 50, an operation unit 60, a display unit 70, an image memory 80, a codec 90, a modem 100, an NCU 110, and a LAN-I. / F (LAN interface) 120, and the units 10 to 120 are connected to each other via a bus 130.

  The MPU 10 controls each unit constituting the multifunction machine 1. The ROM 20 stores a program for controlling the multifunction device 1. The RAM 30 temporarily stores various information related to the multifunction device 1. The RAM 30 stores a misregistration determination pattern 31 for adjusting misregistration (see FIG. 3).

  The reading unit 40 includes a color scanner, reads an image on a document, and outputs RGB signals. Then, after converting the RGB signal into a YMCK signal, binarized image data is output. In the case of FAX transmission, monochrome binary image data is output.

  The recording unit 50 is composed of an electrophotographic color printer using a tandem system, and records received image data and image data of a document read by the reading unit 40 in a copying operation on a recording sheet. Further, the data sent from the personal computer via the LAN-I / F 120 is recorded on the recording paper.

  Specifically, the recording unit 50 includes a printer control unit 510, a data transfer control unit 520, a strobe generation unit 530, and a printer 540. The printer control unit 510 controls each unit constituting the recording unit 50 based on a control signal from the MPU 10. The data transfer control unit 520 transfers image data and the like via the bus 130 to the strobe generation unit 530 and the printer 540.

  The strobe generator 530 includes Y-PWMt 531 to K-PWMt 534 for adjusting the timing of sending the trigger (TRG) signal for each color. Here, PWM indicates pulse width modulation. The strobe generator 530 includes Y-PWMs 535 to K-PWMs 538 that adjust the time for irradiating the photosensitive drums 551 to 554 of the respective colors. That is, when the time for irradiating the photosensitive drums 551 to 554 of each color is adjusted by the Y-PWMs 535 to K-PWMs 538, the density of each color is adjusted. Specifically, the longer the time for irradiating the photosensitive drums 551 to 554 for each color, the higher the density of each color recorded on the recording paper. On the other hand, the shorter the time for irradiating the photosensitive drums 551 to 554 for each color, the lighter the density of each color recorded on the recording paper.

  The printer 540 includes a Y-LED head 541 to a K-LED head 544, photosensitive drums 551 to 554 for each color, developing devices 561 to 564 for each color, transfer devices 571 to 574 for each color, a fixing device 580, and synchronization thereof. It has a CLK590 that controls it. The Y-LED heads 541 to K-LED heads 544 are photosensitive drums 551 to 554 for the respective colors based on the strobe (STB) signals from the Y-PWMs 535 to K-PWMs 538 and the image data from the data transfer control unit 520. Irradiate light. As a result, electrostatic latent images based on the image data from the data transfer control unit 520 are formed on the photosensitive drums 551 to 554 of the respective colors. The developing devices 561 to 564 for the respective colors attach toner to the electrostatic latent images formed on the photosensitive drums 551 to 554. Each color transfer unit 571 to 574 transfers the adhered toner onto a recording sheet. The fixing device 580 fixes the toner on the transferred recording paper. As a result, the image data of the document read by the reading unit 40 is recorded in color on the recording paper.

  The operation unit 60 includes a FAX / copy key for setting the FAX mode or the copy mode, a shortened key for registering a short number or calling from a short number, and a one-touch key for designating a pre-registered FAX number by one touch. I have. The operation unit 60 also includes various operation keys such as a numeric keypad (including * and # keys) for inputting a telephone number or the number of copies, and a start key for starting a document reading operation. A display unit 70 formed of an LCD or the like displays various information such as the operation state of the multifunction machine 1.

  The image memory 80 temporarily stores received image data and image data read by the reading unit 40. The codec 90 encodes (encodes) the monochrome binary image data read by the reading unit 40 using the MH, MR, MMR, JBIG method, or the like for transmission. The codec 90 decodes (decodes) the received image data.

  The modem 100 is an ITU-T recommendation T.30. 30 based on the facsimile transmission control procedure according to 17, V. 27ter, V.L. Modulates and demodulates transmission / reception data according to 29. The NCU 110 controls the connection with the telephone line L and has a function for detecting the transmission and reception of a dial signal corresponding to the telephone number (including the FAX number) of the other party.

  The LAN-I / F 120 is an interface for connecting the multifunction device 1 to a LAN and exchanging data with a personal computer connected to the LAN. For example, it is composed of a NIC (Network Interface Card) or the like and is connected to the LAN via a twisted pair cable or the like.

  Next, in the MFP 1 configured as described above, the operation when the image data of the original read by the reading unit 40, that is, the image data of K, C, M, and Y, is recorded on the recording paper by the recording unit 50 will be described. This will be described with reference to the block diagram shown in FIG. 1 and the timing chart shown in FIG.

  As shown in FIGS. 1 and 2, when the line cycle signal LT is sent from the printer control unit 510 to the data transfer control unit 520 and the printer 540 based on the control signal from the MPU 10, the data transfer control unit 520 The image data (DATA) is sent to the Y-LED head 541 to the K-LED head 544. When transmission of all the image data is completed, the data transfer control unit 520 transmits a load (LOAD) signal to the Y-PWMt 531 to K-PWMt 534.

  As a result, Y-PWMt 531 to K-PWMt 534 send a trigger (TRG) signal to Y-PWMs 535 to K-PWMs 538 in synchronization with the fall of the load (LOAD) signal. Y-PWMs 535 to K-PWMs 538 send strobe (STB) signals to Y-LED head 541 to K-LED head 544 in synchronization with the rise of the trigger (TRG) signal. As a result, the Y-LED heads 541 to K-LED heads 544 are arranged on the basis of the strobe (STB) signals from the Y-PWMs 535 to K-PWMs 538 and the image data from the data transfer control unit 520, respectively. An electrostatic latent image is formed by irradiating light to 551-554. Then, the toner is attached to the electrostatic latent images formed by the developing devices 561 to 564 for the respective colors, and the toner attached by the transfer devices 571 to 574 for the respective colors is transferred onto the recording paper. The toner is fixed. As a result, the image data of the document read by the reading unit 40 is recorded on the recording paper by the recording unit 50.

Next, the misregistration determination pattern 31 stored in the RAM 30 will be described with reference to the explanatory diagram shown in FIG.
As shown in FIG. 3, the RAM 30 stores one line of black (K) having a predetermined length every predetermined interval (for example, 100 lines). Further, with the black (K) in the center in the sub-scanning direction as a reference line, the “deviation” with respect to one line of black (K) at every predetermined interval is increased by one line in the sub-scanning direction and the counter-sub-scanning direction. Each line of cyan (C), magenta (M), and yellow (Y) is stored.

  That is, each line of cyan (C), magenta (M), and yellow (Y) in the anti-sub-scanning direction from the black (K) reference line is “deviation” with respect to one black (K) line at a predetermined interval. Are stored so as to be 0, +1, +2, +3, and +4 lines, respectively. That is, each line of cyan (C), magenta (M), and yellow (Y) in the anti-sub-scanning direction from the black (K) reference line is set to one line at a predetermined interval (100 lines) of black (K). The added value is a predetermined interval (101 lines). Each line of cyan (C), magenta (M), and yellow (Y) is stored for each predetermined interval (101 lines).

  On the other hand, each line of cyan (C), magenta (M), and yellow (Y) in the sub-scanning direction from the black (K) reference line has a “deviation” with respect to one black (K) line at a predetermined interval. , -2, -3, and -4 lines, respectively. That is, for each one line of cyan (C), magenta (M), and yellow (Y) in the sub-scanning direction from the black (K) reference line, one line is subtracted from a predetermined interval (100 lines) of black (K). The obtained value is set as a predetermined interval (99 lines). Then, one line each of cyan (C), magenta (M), and yellow (Y) for each predetermined interval (99 lines) is stored.

  Next, with respect to a method of adjusting the positional deviation of less than one dot by causing the recording unit 50 to record the positional deviation determination pattern 31 stored in the RAM 30 and the timing shown in FIG. This will be described using a chart.

  When a predetermined operation is performed from the operation unit 60, the positional deviation determination pattern 31 is read out. The read misregistration determination pattern 31 is recorded on the recording paper by the recording unit 50. As a result, when there is no position shift in each color, the black (K), cyan (C), magenta (M), and yellow (Y) lines are normalized as shown in the position shift determination pattern 31 shown in FIG. It is recorded at the position. That is, the cyan (C), magenta (M), and yellow (Y) lines are 0, ± 1, ± 2, ± 3, and ± 4, respectively, with respect to one black (K) line at a predetermined interval. Each line is recorded on the recording sheet with a positional shift. In FIG. 4, the distance between one dot is drawn exaggerated from the actual one.

  However, when there is a positional shift in any of the colors, the black (K), cyan (C), magenta (M), and yellow (Y) lines are like the positional shift determination pattern 31 shown in FIG. Is not recorded in the correct position. That is, the cyan (C), magenta (M), and yellow (Y) lines are 0, ± 1, ± 2, ± 3, and ± 4, respectively, with respect to one black (K) line at a predetermined interval. The line is not recorded on the recording paper with the position shifted.

  For example, with respect to one black (K) line at a predetermined interval (100 lines), one line of yellow (Y) at a predetermined interval (101 lines, 99 lines) is only half a dot in the anti-sub-scanning direction. Is recorded on the recording paper, the yellow (Y) positional deviation is adjusted as follows.

  Here, when the resolution of the recording unit 50 is “600 [dpi] × 600 [dpi]”, the distance DL between the dots is about 0.0423 [mm] (= 25.4 [mm] / 600. [Dpi]). When the recording paper conveyance speed is “100 mm / s”, the line cycle LT for recording one line on the recording paper is about 423 μs / line (= 0.0423 mm / s). 100 [mm / s]).

  Therefore, as shown in the timing chart of FIG. 5, only the yellow (Y) trigger (Y-TRG) signal sent from Y-PWMt 531 to Y-PWMs 535 is half the line period LT, that is, 211.5 [μs / line. ] (= 423/2 [μs / line]). That is, the fall time (pulse width) of the trigger (Y-TRG) signal is made half of the line period LT. Then, the strobe (Y-STB) signal is sent from the Y-PWMs 535 to the Y-LED head 541 in synchronization with the rise of the trigger (Y-TRG) signal. As a result, the timing at which the electrostatic latent image is formed on the photosensitive drum 551 is delayed by half a dot. Accordingly, one line of yellow (Y) is displaced by half a dot in the sub-scanning direction, and every predetermined interval (101 lines, 99 lines) with respect to one black (K) line at every predetermined interval (100 lines). One yellow (Y) line is recorded at a regular position. Therefore, it is possible to adjust a positional shift of less than 1 dot.

  It should be noted that the positional deviation of each color can be adjusted in the same manner when cyan (C) and magenta (M) are displaced with respect to one line of black (K) at predetermined intervals. Needless to say, not only a half-dot position shift but also a position shift of less than one dot, such as 1/3 dot or 1/4 dot, can be adjusted in the same manner.

As described above, according to the present embodiment, the following operations and effects can be obtained.
(1) The RAM 30 stores a misregistration determination pattern 31 for adjusting misregistration. When a predetermined operation is performed from the operation unit 60, the misregistration determination pattern 31 is read, and the read misregistration determination pattern 31 is recorded on the recording paper by the recording unit 50. It is determined whether or not the misregistration determination pattern 31 recorded on the recording paper is recorded at a regular position. That is, in the misregistration determination pattern 31 recorded on the recording paper, each line of cyan (C), magenta (M), and yellow (Y) becomes one line of black (K) at every predetermined interval (100 lines). On the other hand, it is determined whether each of 0, ± 1, ± 2, ± 3, and ± 4 lines is recorded with a positional deviation. Based on the determination result, the trigger (TRG) signal of the color shifted in Y-PWMt 531 to K-PWMt 534 changes the fall time (pulse width). Then, in synchronization with the rise of the trigger (TRG) signal, a strobe (STB) signal is sent from the Y-PWMs 535 to K-PWMs 538 to the Y-LED head 541 to the K-LED head 544. As a result, the timing at which the electrostatic latent images are formed on the photoconductor drums 561 to 564 having the color misalignment is also changed. Accordingly, it is possible to adjust a positional shift of less than one dot.

  (2) In the misregistration determination pattern 31, each line of cyan (C), magenta (M), and yellow (Y) is 0 for one line of black (K) every predetermined interval (100 lines). The position is shifted by ± 1, ± 2, ± 3, and ± 4 lines. For this reason, when there is a positional shift in any of the colors, the shifted color is not recorded in the regular position. Therefore, based on the “shift” with respect to one black (K) line as a reference, It is possible to easily determine how much misalignment occurs in the sub-scanning direction or the anti-sub-scanning direction. Therefore, it is possible to adjust a positional shift of less than one dot based on the determination result of the positional shift.

In addition, the said embodiment can also be changed and actualized as follows.
3. Instead of the configuration in which the misregistration determination pattern 31 shown in FIG. 3 is stored in the RAM 30, a document of the normal misregistration determination pattern shown in FIG. 4 is prepared in advance, and the original is read by the reading unit 40. The recording unit 50 may be configured to record on the recording paper.

  The position deviation determination pattern 31 shown in FIG. 6 may be used. That is, as shown in FIG. 6, one line of black (K) having a predetermined length is stored at every predetermined interval (100 lines). Further, with the black (K) in the center in the sub-scanning direction as a reference line, the “deviation” with respect to one line of black (K) at every predetermined interval is increased by one line in the sub-scanning direction and the counter-sub-scanning direction. Each line of cyan (C), magenta (M), and yellow (Y) is stored. That is, one line of cyan (C), magenta (M), and yellow (Y) in the sub-scanning direction and the counter-sub-scanning direction from the black (K) reference line is one line of black (K) at predetermined intervals. Are stored so that the “deviation” with respect to is 0, +1, +2, +3, +4 lines, respectively. That is, one line each of cyan (C), magenta (M), and yellow (Y) in the sub-scanning direction and the counter-sub-scanning direction from the black (K) reference line is a predetermined interval (100 lines) of black (K). A value obtained by adding one line to is defined as a predetermined interval (101 lines). Then, one line each of cyan (C), magenta (M), and yellow (Y) is stored for each predetermined interval (101 lines). With this configuration, when there is no positional deviation between the colors, one line of cyan (C), magenta (M), and yellow (Y) at a predetermined interval (101 lines) is set at a predetermined interval (100 lines). Recording is performed at a position separated from the black (K) reference line rather than one black (K) line. As a result, it is possible to easily determine in which direction the position is shifted in the sub-scanning direction or the anti-sub-scanning direction.

The above-described embodiment may be applied to an intermediate transfer method in which image data is once transferred to an intermediate body and then transferred to a recording sheet.
The above-described embodiment may be applied to a thermal or inkjet color printer instead of an electrophotographic color printer.

  The above embodiment may be applied not only to a color printer but also to a monochrome printer. If comprised in this way, the timing which records image data on a recording paper can be adjusted with less than 1 dot.

Furthermore, the technical idea grasped from the above embodiment will be described below together with the effects thereof.
[1] The control means sends a trigger signal based on a load signal indicating the end of data transfer. If comprised in this way, position shift of less than 1 dot can be adjusted.
[2] The printer is a tandem color printer. With this configuration, it is possible to provide a tandem color printer capable of adjusting a positional shift of less than one dot.

1 is a block diagram illustrating a configuration of a multifunction machine. 5 is a timing chart showing an operation when recording image data of a read original on recording paper. Explanatory drawing which shows a position shift determination pattern. Explanatory drawing which shows the result of having recorded the position shift determination pattern on the recording paper. 6 is a timing chart showing an operation when a yellow (Y) position shift is adjusted. Explanatory drawing which shows the position shift determination pattern in another embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... MFP as a printer (color printer), 10 ... MPU constituting control means, 20 ... ROM constituting control means, 30 ... RAM constituting control means, 50 ... Recording unit, 510 ... Constructing control means Printer controller 531 to 534... Y, M, C, K-PWMt as adjusting means, 541 to 544... Y, M, C, K-LED head as head, LOAD... Load signal, Y, M,. C, K-STB ... strobe signal, Y, M, C, K-TRG ... trigger signal.

Claims (4)

Control means for controlling a plurality of heads, a strobe signal for adjusting the time of light irradiation from each head, and a trigger signal comprising a pulse signal for adjusting the transmission timing of the strobe signal, and adjusting the pulse width of the trigger signal And a control means for sending a strobe signal based on the end of the trigger signal.
When the head to be adjusted is less than 1 dot and is displaced in the anti-sub-scanning direction with respect to the reference head, the adjustment means adjusts the pulse width of the trigger signal corresponding to the head to be adjusted. , By delaying the end timing of the trigger signal by a time obtained by multiplying the line period by the ratio of the amount of displacement with respect to 1 dot, to adjust the displacement of less than 1 dot in the anti-sub-scanning direction,
When the head to be adjusted with respect to the reference head is less than 1 dot and displaced in the sub-scanning direction, the adjustment means adjusts the pulse width of the trigger signal corresponding to the head to be adjusted, A printer characterized by adjusting a positional deviation of less than one dot in the sub-scanning direction by advancing the trigger signal end timing by a time obtained by multiplying a line period by a ratio of a positional deviation amount with respect to one dot. The printer according to claim 1.
The printer is an electrophotographic color printer using a tandem method,
The printer is characterized in that the head is composed of heads corresponding to four colors of yellow, magenta, cyan, and black, respectively. The printer according to claim 2.
Storage means for storing a positional deviation determination pattern for determining the positional deviation;
The positional deviation determination pattern is
One black line having a predetermined length at predetermined intervals;
Using the central line in the black sub-scanning direction as a reference line, each one of cyan, magenta, and yellow with a positional deviation with respect to one black line at predetermined intervals increased by one line in the sub-scanning direction and the counter-sub-scanning direction. A printer comprising a line. The printer according to claim 3.
A printer comprising: an operation unit configured to read the misregistration determination pattern from the storage unit and record the read misregistration determination pattern on a recording sheet.

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