JPH02212860A - Copying machine with magnification correcting function - Google Patents

Abstract

PURPOSE:To easily correct magnification by reading actual copy magnification by using an image sensor and calculating a corrected value automatically. CONSTITUTION:The position of a lens 19 arranged between a document 11 and a photosensitive body 20 is controlled by a lens control part 4 according to the correcting value and the moving speed of a scanner 10 is controlled by a scanner control part 5 according to the correcting value to make a variable magnification copy. This copying machine is equipped with image sensors 1 and 21 which are arranged at positions of length conjugate to the distance from the document to the photosensitive body 20. Further, the copying machine is equipped with a means 2 which measures the current actual magnification by comparing the length of image information read by image sensors 1 and 21 with predetermined reference length and a means 3 which calculates the corrected value for the position of the lens and the moving speed of the scanner 10 from the measured magnification. Consequently, the magnification correcting operation is facilitated.

Description

Detailed Description of the Invention (al Industrial Field of Application) This invention corrects the position of a lens placed between an original and a photoreceptor and the scanning speed of the original (moving speed of the scanner) based on correction values. The present invention relates to a copying machine that can accurately perform copy processing at a desired magnification.

BACKGROUND ART Conventional copying machines scan a document on a document table with a scanner that includes a light source, and the reflected light forms an image on a photoreceptor through a plurality of mirrors and lenses. By changing the moving speed of the scanner, the magnification in the scanning direction can be changed, and by changing the position of the lens, the magnification in the direction perpendicular to the scanning direction can be changed. The moving speed of the scanner and the position of the lens are set according to the magnification input from the operation panel on the main body of the copying machine, thereby allowing the user to obtain a copy image with the desired magnification.

However, the moving speed of the scanner and the position of the lens may deviate as the scanner is used, and it may become impossible to copy at the same magnification as input from the operation panel. Therefore, conventionally, during maintenance, a specific magnification was set, the copy was actually made, the length of the copied image was measured, the actual magnification was calculated, and the motor rotational speed and lens position were corrected based on that. It was possible to copy at a magnification of .

(C1 Problem to be solved by the invention) However, in the conventional magnification correction method, a service person actually makes a copy and then determines the correction value, and based on that, changes the constant value on the scan motor drive board, or Home position sensor (LHP)
This method is designed to shift only the correction value bone from the position of S), and the service person has to read the length of the copied image to find the actual magnification and correction value, and also has to make the copy several times to make the correction. Accurate correction cannot be made without repeating the process, which is a very time-consuming problem.

An object of the present invention is to provide a copying machine having a magnification correction function that can easily perform magnification correction by reading the actual copy magnification using an image sensor and automatically calculating a correction value. do.

(Means for Solving Problem d1) Figure 1 is a diagram showing the configuration of the present invention, in which the position of the lens placed between the original and the photoreceptor is controlled by the lens control unit 4 based on the correction value. In a copying machine that performs variable magnification copying by controlling the moving speed of the scanner based on a correction value by a scanner control unit 5, an image sensor 1 is arranged at a position conjugate with the distance from the original to the photoreceptor. and means 2 for measuring the actual magnification at that time by comparing the length of the image information read by the image sensor with a predetermined reference length, and determining the position of the lens 4 and the position of the scanner 5 from the measured magnification. The present invention is characterized in that a means 3 for calculating a correction value of the moving speed is provided.

Te) Effect In the copying machine of the present invention, since the distance between the original and the photoreceptor is the same as the distance between the original and the image sensor, the size of the image information read by the image sensor 1 is smaller than that of the image sensor. The size of the image information formed on the body is the same, and the magnification of the actually formed copy image is measured by comparing the length of the image information read by the image sensor 1 with a predetermined reference length. Ru. For example, set the lens position and scanner movement speed to values that should be the same size,
The image information at that time is read by the image sensor 1, and the image information is converted into a predetermined standard length (the length when it is the same size)
The actual magnification at that time is determined by comparing with the actual magnification (magnification measuring means 2). The correction value calculation means 3 calculates that the actual magnification is the set magnification (
Calculate the correction value so that it matches the actual size (equal magnification). According to this correction value, the lens control unit 4 and scanner control unit 5 control the lens and scanner to ensure an accurately set magnification (same magnification).
to enable copy processing.

(f) Embodiment FIG. 2 is a schematic diagram of a copying machine according to an embodiment of the present invention.

A document table 11 made of transparent glass or the like is provided on the top surface of the copying machine main body, and the document to be copied is placed on this document table 11. An optical device including a light source 12, six mirrors 13 to 18, and a lens 19 is arranged below the document table 11. Light source 12 and mirror 13
constitutes a light source unit and moves in the directions of arrows F and R in the figure. The mirrors 14 and 15 constitute a mirror unit and move in the directions of arrows F and R at the speed of the light source unit. A light source unit and a mirror unit constitute a scanner 10 that scans an original. As the scanner 10 moves, the original on the original platen 11 is scanned, and the reflected light from the original is reflected on the mirror 13.
18 and a lens 19 to a photoreceptor 20 in the center of the copying machine main body. This reflected light from the original causes the photoreceptor 2 to
A latent image corresponding to the original image is formed on the original image.

The copying magnification is determined by the moving speed of the scanner 0 and the position of the lens 19. That is, during the copying operation, the angry light body 20
is rotated at a constant speed in the direction of the arrow in the figure, so if the moving speed of the scanner 10 is slowed down, the copied image will be enlarged in the scanning direction.
If the moving speed is increased, the copied image is reduced in the scanning direction. The movement of the scanner 10 is controlled by a scanner motor (not shown). The moving speed of the scanner is set according to the copying magnification input from the operation panel on the copying machine main body, but the moving speed of the scanner (rotational speed of the scanner motor , load on the scanner, etc.), it becomes possible to obtain a copy image with accurate magnification in the scanning direction.

Furthermore, by moving the lens 19 in the direction 19' in the figure, a copy image enlarged in the direction perpendicular to the scanning direction can be obtained.
By moving in the direction of 9'', a reduced image can be obtained.

The eclipse lens 19 is moved by driving a lens motor (not shown), and a home position serving as a reference for its moving position is set based on detection by a lens home position sensor (LHPS). The rotational state of the lens motor is detected by an encoder, and the lens 19 is thereby moved by a predetermined distance. The lens motor moves the lens 19 by a predetermined pulse amount based on the copy magnification input from the operation panel on the top of the copier body and the detected value of LHPs. At this time, the lens motor moves the lens 19 by a predetermined pulse amount.
l (The actual home position is shifted from the PS position to control the movement of the lens so that accurate magnification setting can be performed.

Mirror 18 is rotatably held at positions 18 and 18' as shown. The mirror 180 is rotated by turning on and off a solenoid (not shown).

When this mirror is at position 18, mirrors 13 to 1
The reflected light from the original guided by the mirror 7 is reflected by the mirror 18 and irradiated onto the photoreceptor 20 . However, the mirror is 1
When rotated to the position 8', the reflected light from the document is guided in the direction of the image sensor 21. mirror 1
The distance from the mirror 18 to the photoreceptor 20 is the same as the distance from the mirror 18 to the image sensor 21. That is,
The distance between the original and the photoreceptor 20 is the same as the distance between the original and the image sensor, and the size of the image formed on the photoreceptor 20 and the size of the image read by the image sensor 21 are the same.

FIG. 4 is a block diagram of the main parts of this copying machine.The scanner motor 32, the lens motor 33, the solenoid 34 that rotates the mirror 18, etc. are set to H by CF'U31. B is given. The CPU 31 outputs a predetermined drive signal to the scanner motor 32 according to the copy magnification and the magnification correction value input from the operation panel 35, and outputs a drive signal to the lens motor 33 according to the copy magnification, the input from the LHPS, and the magnification correction value. Output. Also, when the magnification adjustment mode (mode for correcting the motor rotation speed, lens home position, etc.) is selected, the solenoid 34 is operated to adjust the mirror 1.
The reading circuit 36 is a circuit that detects the length of image information read by the image sensor 21.

In the magnification adjustment mode, a reference original as shown in FIG. 3 is used, and its reflected light is read by the image sensor 21. The reference document (on the right side of the figure) has a length in the scanning direction (arrow F), and a reference line with length L2 drawn in the direction perpendicular to the scanning direction. The length of is stored in advance in the memory of the copying machine main body. This reference document is placed on the document table 11, the lens 19 is set to the same-size copying position (home position), and the scanner (scanner motor) is set at the reference speed Vi. When the original is scanned by moving at the same speed as when copying at the same size, the image sensor 21 reads the image information of the reflected light. And LI and L in the reference manuscript! The image lengths 11 and 7!2 corresponding to are measured by the reading circuit 36. CPU
31 is the measured length! lI,t! The actual magnification is determined from z and the previously stored lengths Ll and L, and furthermore, the correction values for the lens home position and the moving speed of the scanner are determined from the magnification.

■Scanner movement speed correction value The correction value in the scanning direction is determined by the following equation.

K+-L+/it To use this correction value to correct the moving speed of the scanner during actual copying, the moving speed 8 of the scanner motor can be corrected using the following equation.

■Ya-”Kr　・V8゜7M Here, M represents the copy magnification.

■Correction value for the lens home position The correction value □ in the direction perpendicular to the scanning direction is determined by the following formula.

Kz-1t/Lx 1 Therefore, when actually performing the copying process, the home position of the lens may be corrected based on this correction value.The shift position ΔL of the home position can be obtained by the following equation.

ΔL=Ll/2XK! Here, Lo indicates the distance between the document and the home position at the time of magnification measurement, and the home position is shifted by Δ with this distance MLo as a reference. For example, when ΔL>0, the home position is shifted by Δ to the photoreceptor side,
When L<0, the home position may be shifted by Δ toward the document side. FIG. 5 is a flowchart showing the processing procedure in the magnification correction mode.

When the magnification correction mode is set, the solenoid 34 is turned on at 01, and the mirror 18 is rotated to the position 18'. When the reference original shown in Fig. 3 is placed on the original table II and the copy start button is pressed, the lens moves to the same magnification position (home position) and the scanner 10 moves at the reference speed to scan the original. (rh2→n3→n4→n5→n6)
, the reflected light from the reference original enters the image sensor 21, and when the scanning of the original is completed, 1. and e2 are read by the reading circuit 36 and stored in the memory (n7→n8→
n9→n10). Correspondingly, the correction value Kz is calculated and stored in the memory (n11, n12L).The next time a copy is made, the lens home position and scanner movement speed are set based on this correction value 1 and 2. In this way, +, Kz is added to the correction value.
If it is determined, the solenoid 34 is turned off and the magnification correction mode ends (n13).

In this embodiment, the lens position and scanner movement speed are set to equal magnification in the magnification correction mode to obtain the correction value, but the correction value may also be obtained in a variable magnification state. In that case, the variable magnification may be taken into consideration at the stage of calculating the correction value.

(g) Effects of the Invention As described in (g) above, according to the present invention, the correction value for the scanner's moving speed and the correction value for the lens position are automatically determined from the image information read by the image sensor, so it is possible to This eliminates the trouble of calculating correction values using the image sensor, which facilitates magnification correction work and prevents wasteful use of toner, paper, and the like. In addition, the image WI read by the image sensor
Since the correction value is automatically determined from the information, it is possible to prevent errors and make accurate corrections.Figure 3 is a schematic configuration diagram of a copying machine that is an embodiment of this invention. FIG. 4 is a block diagram of the main parts of the copying machine, and FIG. 5 is a flowchart showing the processing procedure in the magnification correction mode.

one scanner, A light source, ~18-Mirror one lens, One photosensitive body, -Image scanner.

Claims (1)

[Claims] (1) In a copying machine that performs variable magnification copying by setting the position of a lens placed between the original and the photoreceptor and the moving speed of the scanner based on correction values, the distance from the original to the photoreceptor and the conjugate an image sensor disposed at a long position, a means for measuring the actual magnification at that time by comparing the length of the image information read by the image sensor with a predetermined reference length, and a means for measuring the actual magnification at that time, based on the measured magnification. 1. A copying machine having a magnification correction function, comprising: means for calculating a correction value based on a lens position and a scanner movement speed.