JP2006305984A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which can perform an image forming position adjustment (resist adjustment) which is simple and highly accurate. <P>SOLUTION: This image forming device comprises a printing means 3, an operating means 2, a memory means 4, and a controlling means 1. In this case, the printing means 3 prints a pattern 11 for an image forming position adjustment comprising a scale pattern 12. The operating means 2 inputs an image forming position adjustment mode. The memory means 4 holds the pattern for the image forming position adjustment. The controlling means 1 makes the memory means 4 store the correction value when a resist correction value which is read from the printed pattern for the image forming position adjustment is input in the operating means 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus characterized by an image forming position adjustment technique.

In an electrophotographic digital image forming apparatus, an original is read by a scanner, and a latent image is formed by writing on a photosensitive member with a laser beam modulated based on image data, and the latent image is passed through a developing device. A process is performed in which toner is attached and the toner image is transferred onto a transfer sheet conveyed from a paper feeding device using a transfer unit.
In this process, if the writing timing of the laser writing unit is misaligned, the assembly accuracy of the paper feeding / conveying device is poor, or the conveyance speed and paper feeding timing vary, the registration position of the transfer paper and image Since a deviation occurs in (image forming position), it is necessary to adjust the writing timing of the laser writing unit, the paper feeding timing of the paper feeding device, and the like in order to match the registration position of the image with the reference value.
Conventionally, in this adjustment, a test chart is read by a scanner, a deviation amount from the copy image is measured with a ruler, a correction value is calculated from the distance, and the correction value is input to the CPU by an input from an operation panel or the like. Etc., and a method of correcting the writing timing of the laser writing unit, the paper feeding timing of the paper feeding device, etc. to a regular timing has been used.
In such an image position adjustment method, a measuring instrument such as a ruler is required for adjustment, and there is a problem in that the measurement accuracy is low and the correction value must be input after performing troublesome calculations. . Furthermore, it cannot be implemented in an image forming apparatus that does not have a scanner such as a laser printer.
For example, in Patent Document 1, a plurality of test patterns for printing position adjustment are printed, a sample printed at the most appropriate position is selected from the output samples, and a target adjustment value is input based on the sample. An adjustment technique has been proposed.
JP 2003-266898 A

In the above prior art, it is necessary to print a plurality of samples for adjustment, and there is a problem that a lot of useless printing has to be performed, and the cost for adjustment increases. Furthermore, when an appropriate print sample is selected visually, the adjustment accuracy is low, and in order to adjust with high accuracy, the output sample must be measured with a ruler or the like, and a measuring instrument is prepared or measured. There is annoyance that must be.
An object of the present invention is to provide an image forming apparatus capable of performing image formation position adjustment (registration adjustment) easily and with high accuracy.

In order to achieve the above object, the invention described in claim 1 is a printing means for printing an image forming position adjustment pattern composed of scale patterns, an operating means for inputting an image forming position adjustment mode, and an image forming position adjustment. An image forming apparatus comprising memory means for holding a pattern, and control means for storing the correction value in the memory means when a registration correction value read from the printed image forming position adjustment pattern is input to the operation means Is the most important feature.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the image forming position adjustment pattern is printed mainly up to the end of the transfer paper.
According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the image forming apparatus is characterized in that the image forming position adjusting pattern is formed in an oblique direction with respect to the transfer sheet conveying direction.
According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, an image forming apparatus having a function of limiting an image forming position adjustment target to either main scanning or sub scanning is a main feature.
According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, an image forming apparatus in which the writing position of the image forming position adjusting pattern is variable is a main feature.

In the first and second aspects of the invention, since the scale printed on the image forming position adjusting pattern printed on the transfer paper can be directly read and input, the measuring instrument and the skilled adjuster can be used. This is not necessary, and even a general user can easily adjust the image forming position.
According to the third aspect of the present invention, since the adjustment step can be made finer with respect to the scale interval of the image formation position adjustment pattern, the image formation position can be adjusted with high accuracy.
According to the fourth aspect of the present invention, since unnecessary printing of the image forming position adjustment pattern can be suppressed, it is possible to adjust the image forming position while reducing the toner contamination in the machine and further reducing the influence on durability. .
According to the fifth aspect of the present invention, since the toner contamination position can be dispersed, the image forming position can be adjusted with less influence on the durability.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a functional block diagram of an image forming apparatus according to an embodiment of the present invention. An operation unit 2, a printing unit 3, and a memory unit 4 are connected to the CPU (control unit) 1. Its function will be described later.
FIG. 2 is a diagram illustrating a first example of an image forming position adjustment pattern. The image forming position adjustment pattern 11 includes a scale pattern 12 and a number pattern 13 with plus and minus attached to the scale. This image forming position adjusting pattern 11 is printed on the transfer paper. Reference numeral 14 denotes a scale pattern printed outside the transfer paper area, and 15 denotes a numerical pattern printed outside the transfer paper area.
Next, an actual image forming position adjusting operation will be described. When adjusting the image forming position, the adjuster first selects an image forming position adjustment mode from the operation unit 2. When this mode is selected, the CPU 1 instructs the printing unit 3 to print the image forming position adjustment pattern 11 shown in FIG. 1 stored in the memory unit 4. Upon receiving this command, the printing unit 3 prints the image forming position adjusting pattern 11.
The image forming position adjustment pattern 11 is printed with timing control such that the position of the scale 0 coincides with the end of the transfer paper P. That is, when the position of the scale 0 coincides with the end portion of the transfer paper P, there is no registration deviation (registration is matched). The image formation position adjustment pattern 11 may be printed outside the transfer paper area as indicated by the scale pattern 14 and the numeric pattern 15, but this is transferred in an area other than the image formation position adjustment pattern 11. What is necessary is just to apply reverse bias to the paper P and perform transfer cleaning.
When the CPU 1 finishes printing the image forming position adjustment pattern 11, the CPU 1 switches the operation means 2 to an adjustment value input screen. The adjuster visually reads the value of the memory means 4 at the portion located at the end of the transfer paper of the printed image forming position adjusting pattern 11. In the example of FIG. 2, it can be read as about −2.6. The value read here is input to the adjustment value input screen.
The CPU 1 calculates image forming position correction data based on the input adjustment value, stores it in the memory means 4, and ends the image forming position adjustment mode. By performing printing based on the correction value stored in the memory means 4, it is possible to print an image with no registration error.

FIG. 3 is a diagram showing a second example of the image forming position adjustment pattern. In the second example of the image formation position adjustment pattern 11 shown in FIG. 3, the image formation position adjustment pattern 11 is printed obliquely with respect to the transfer paper P.
FIG. 4 is an explanatory diagram showing the principle of adjustment value measurement using the image forming position adjustment pattern shown in FIG. A line segment AB represents the length of one scale when the image forming position adjusting pattern 11 is arranged in the vertical direction, and a line segment AC arranges the image forming position adjusting pattern 11 in an oblique direction (FIG. 3). Example) represents the length of one scale. The lengths of the line segment AB and the line segment AC are the same. The line segment AC is arranged with an angle of θ with respect to the line segment AB.
The registration adjustment amount that can be measured by the one-scale line segment AC of the image forming position adjustment pattern 11 arranged in the oblique direction is represented by the length of the line segment AD. The length of the line segment AD is AD = AC cos θ
It can be expressed as That is, by forming the image forming position adjustment pattern 11 at an angle θ with respect to the transfer sheet conveyance direction, it is possible to calculate the adjustment value with the same scale interval and with an accuracy of 1 / cos θ.

Example 1
FIG. 5 is a flowchart showing the control operation of the first embodiment. When the adjustment mode is selected, the CPU 1 displays an adjustment mode input screen on the operation means 2 (S1), and prompts the adjuster to select the adjustment mode. The adjustment mode is selected from adjustment only for main scanning, adjustment only for sub-scanning, and adjustment for both main scanning / sub-scanning. The adjuster determines a desired adjustment item from the current state of the image forming apparatus, and selects an adjustment mode according to the adjustment item (S2).
In accordance with the selected adjustment mode (S3), the CPU 1 prints the image forming position adjustment pattern 11 necessary for the adjustment by the printing unit 3. If the adjustment is only for main scanning, it will be at the left or right edge of the transfer paper (S4), if it is only for sub scanning, it will be at the leading edge of the transfer paper (S5), and if it is for both main scanning and sub scanning, The image forming position adjustment pattern 11 is printed and output on both the left end or the right end and the transfer paper front end (S6).
The adjuster reads the adjustment value from the printed image forming position adjustment pattern 11 (S7) and inputs it to the operation means 2 (S8). The CPU 1 stores the input adjustment value in the memory means 4 (S9), and ends the adjustment mode.

(Example 2)
The CPU 1 stores the previous image forming position adjustment pattern printing position on the memory unit 4. When printing the image formation position adjustment pattern 11, the previous image formation position adjustment pattern print position information on the memory means 4 is referred to, and an image formation position adjustment pattern is added to a position obtained by adding a certain value thereto. 11 is printed. When printing is completed, the current image forming position adjusting pattern printing position is overwritten on the previous image forming position adjusting pattern printing position on the memory means 4. By doing so, it is possible to change the print position of the image forming position adjustment pattern 11 every time it is printed.
For example, when printing the image forming position adjusting pattern 11 in the sub-scanning direction, the image forming position adjusting pattern 11 is printed on the leading edge of the transfer paper, and therefore the print position in the main scanning direction of the image forming position adjusting pattern 11 is stored. In addition, the position of the image forming position adjustment pattern 11 in the main scanning direction is changed. Similarly, when printing the image forming position adjusting pattern 11 in the main scanning direction, the printing position in the sub scanning direction of the image forming position adjusting pattern 11 is stored, and the sub scanning of the image forming position adjusting pattern 11 is performed. Change the direction position.
In addition, by generating a random numerical value by the CPU 1 and using this as printing position information, the printing position of the image forming position adjusting pattern 11 can be changed every time printing is performed.

1 is a functional block diagram of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows the 1st example of the pattern for image formation position adjustment. It is a figure which shows the 2nd example of the pattern for image formation position adjustment. It is explanatory drawing which shows the principle of the adjustment value measurement by the image formation position adjustment pattern shown in FIG. 3 is a flowchart illustrating a control operation according to the first embodiment.

Explanation of symbols

1 CPU (control means)
2 Operating means 3 Printing means 4 Memory means 11 Image forming position adjusting pattern 12 Scale pattern

Claims (5)

  Printing means for printing an image forming position adjustment pattern composed of scale patterns, operation means for inputting an image forming position adjustment mode, memory means for holding the image forming position adjustment pattern, and printed image forming position adjustment An image forming apparatus comprising: a control unit that stores the correction value in the memory unit when the registration correction value read from the pattern for use is input to the operation unit.   The image forming apparatus according to claim 1, wherein the image forming position adjusting pattern is printed up to an end portion of a transfer sheet.   The image forming apparatus according to claim 1, wherein the image forming position adjusting pattern is formed in an oblique direction with respect to a transfer sheet conveyance direction.   The image forming apparatus according to claim 1, wherein the image forming apparatus has a function of limiting an image forming position adjustment target to either main scanning or sub scanning.   2. The image forming apparatus according to claim 1, wherein a writing position of the image forming position adjusting pattern is variable.

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