JPH03186866A - Color copying machine - Google Patents

Abstract

PURPOSE:To eliminate the superposition deviation of a toner image by fixing the lighting timing of an exposure lamp for the second and subsequent scanning of an identical original based on a rotational position signal corresponding to the start of the preceding scanning. CONSTITUTION:A rotational position detection means 56 generates the rotational position signal every time that a rotor 11 is rotated once. Then, when a color copied image obtained by superposing the respective toner images is formed on the rotor 11, the plural times of the scanning of the identical original D are respectively started based on the rotational position signal. Besides, the lighting timing of the exposure lamp 24 for the second and subsequent scanning of the identical original is fixed based on the rotational position signal corresponding to the start of the preceding scanning. Thus, the color copied image with high quality and without the superposition deviation of the toner image is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color copying machine capable of forming a color copy image by superimposing toner images of various colors.

[Conventional technology]

Conventionally, in a copying machine configured to move a scanner incorporating an exposure lamp for irradiating the original back and forth, and scan the original as the scanner moves forward, the time when a predetermined amount of light is reached after the exposure lamp is turned on. By starting the forward movement of the scanner at , and extinguishing the exposure lamp when the forward movement ends, power consumption is reduced and the exposure lamp is prevented from overheating (Japanese Patent Laid-Open No. 50-34540).

In addition, as shown in Japanese Patent Publication No. 61-54210, when scanning multiple times in so-called continuous copying (multi-copying) in which multiple copies of the same original are formed, the forward movement of the scanner is terminated. By turning on the exposure lamp, which was once turned off during the scanner's backward movement, and immediately starting the forward movement for the next scan after the end of the backward movement, the copying time per copy image can be shortened. In other words, monochrome copying machines are known that aim to increase the number of copies (number of copies) that can be formed per unit time.

Now, a color copying machine using an electrophotographic process forms a color copy image corresponding to a document by superimposing toner images of a plurality of colors. In particular, color copying machines use a single light source to scan to read a document and to expose to form a latent image on a photoreceptor. scan. As a result, a latent image of the document separated by color is formed on the photoreceptor for each scan, and the latent image is developed to form toner images of mutually different colors.

Note that a normal color copying machine can selectively form a color copy image and a monochrome copy image consisting of a toner image of one color.

In forming a color copy image, a method for transferring each toner image onto copy paper is to sequentially transfer the E. toner images onto the copy paper wrapped around a predetermined position on the circumferential surface of a transfer rotating body. There is a method in which the toner images are superimposed, and a method in which the toner images superimposed on a photoreceptor or a transfer rotary member are transferred all at once onto copy paper.

Conventional color copying machines are equipped with a rotational position sensor to detect the rotational angular position of a rotating body (photoreceptor or transfer rotating body) that is rotated in response to scanning to superimpose toner images. The scanning of the document is controlled based on a rotational position signal generated by a rotational position sensor every time the transfer rotary body rotates once.

That is, first, the exposure lamp is turned on at the timing when the rotational position signal is generated, and the fixed time required for the light intensity of the exposure lamp to reach a predetermined value and become stable is counted, and at the end of the timing, the scanner is turned on. Start forward movement (scanning of original). Then, at the end of the forward movement time of the scanner, which is determined by the size of the document, the copying magnification, etc., the exposure lamp is turned off and the scanner is moved back.

[Problem to be solved by the invention]

In conventional color copying machines, scanning starts after the stabilization time of the exposure lamp has elapsed from the generation timing of the rotational position signal, so the timing of starting scanning may vary from scan to scan due to errors in the timer that measures the stabilization time. There were times when there was a slight change in the generation timing of the rotational position signal.

For this reason, there is a problem in that a slight misalignment occurs in the superposition (resist) of each toner image, making it impossible to obtain a high-quality color copy image.

In addition, when forming a monochrome copy image, there is no need to superimpose multiple toner images, but in conventional color copying machines, even when forming a monocolor copy image, the rotational position signal mentioned above is used as a reference for scanning. Control is performed, and the time for forming one copy image becomes the rotation period of the rotating body for superimposing the toner images.

Therefore, when performing multi-copying of monochrome copies, there is wasted waiting time between the end of the scanner's return movement and the generation of the next rotational position signal, and the number of copies per unit time is lower than that of conventional monochrome copying machines. There was a problem that it was lower than that of . In other words, conventional color copying machines are slower than monochrome copying machines when it comes to copying monochrome images.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to eliminate misregistration of toner images and to make it possible to form high-quality color copy images. Another object of the present invention is to provide a color copying machine capable of increasing the number of copies of monochrome images per unit time.

[Means to solve the problem]

In order to solve the above-mentioned problem, the invention of claim 1 provides a scanner that moves back and forth to scan a document, an exposure lamp built into the scanner to irradiate the document, and a scanner that moves back and forth to scan the document. an exposure lamp control means that turns on the exposure lamp to irradiate the document with a predetermined amount of light and turns off the exposure lamp when the forward movement of the scanner is completed; a plurality of developing means for forming a toner image by developing a latent image formed by the scanning; a rotating body that rotates in response to scanning in order to superimpose each of the toner images; and a rotational position detection means for generating a rotational position signal at the same time, and the plurality of developing means sequentially form toner images of each color on the same document and superimpose them on the rotating body to form a color copy image. In a color copying machine capable of forming a color copy image, when forming the color copy image, multiple scans of the same original are started based on the rotational position signal, and the second and subsequent scans of the same original are started. The lighting timing of the exposure lamp is determined based on the rotational position signal corresponding to the start of the previous scan.

A second aspect of the invention provides a scanner that moves back and forth to scan a document, an exposure lamp built into the scanner to irradiate the document, and irradiates the document with a predetermined amount of light when the scanner moves forward. an exposure lamp control means that turns on the exposure lamp when the scanner finishes forward movement, and turns off the exposure lamp when the forward movement of the scanner is completed; and a latent image formed by scanning the document using toners of different colors. a plurality of developing means for developing toner images to form toner images; a rotating body that rotates in response to scanning in order to superimpose each of the toner images; and a rotating body that generates a rotational position signal every rotation of the rotating body. a position detecting means, a color copy image in which toner images of each color are sequentially formed on the same document by the plurality of developing means and superimposed on the rotating body; and one color copy image for the document; In a color copying machine capable of selectively forming a monochrome copy image using only a developing means, when forming the color copy image, the same document is scanned multiple times based on the rotational position signal. The present invention is characterized in that when the monochrome copy image is formed, scanning of the original is started at an appropriate time regardless of the rotational position signal.

[For production]

The scanner moves back and forth to scan the document.

An exposure lamp is incorporated into the scanner and illuminates the document.

The exposure lamp control means turns on the exposure lamp to irradiate the document with a predetermined amount of light when the scanner moves forward, and turns off the exposure lamp when the scanner ends the forward movement.

The plurality of developing means each uses toner of a different color to develop the latent image formed by scanning the document to form a toner image.

The rotating body rotates in response to scanning in order to superimpose the respective toner images.

The rotational position detection means generates a rotational position signal every rotation of the rotating body.

When forming a color copy image in which the toner images are superimposed on the rotary body, multiple scans of the same document are started based on the rotational position signal, respectively;
The lighting timing of the exposure lamp for the second and subsequent scans of the same document is determined based on the rotational position signal corresponding to the start of the previous scan.

When forming a monochrome copy image using only one developing means for the original, scanning of the original is started at an appropriate time regardless of the rotational position signal.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional front view showing the general structure of a color copying machine 1. As shown in FIG.

Approximately in the center of the main body of the color copying machine 1 is a photosensitive drum 2.
is arranged so as to be rotatable in the clockwise direction, and the photosensitive drum 2
Surroundings are a cleaner unit 3, a main eraser lamp 4, a charger 5, and an LED as a partial eraser.
An array 6, developing units 7 to 10, and a transfer plate 11 as an intermediate transfer medium are provided. The photosensitive drum 2 is provided with a photosensitive layer on its surface, and the surface is uniformly charged by passing through a main eraser lamp 4 and a charging charger 5, and is charged by an optical system 40 (described later) to form a latent image. exposed to light.

Each developing device 7, 8, 9.10 has yellow (Y)
), magenta (M), cyan (C), blank (BK)
A toner empty sensor 7a to 8 stores toner of each color and detects a shortage of toner of each color.
a, 9a, and lOa are provided.

Note that the developing units 7 to 10 are not limited to a type in which they are fixedly arranged around the photoreceptor drum 2; for example, the developing units 7 to 10 may be integrated and movable in two downward directions. Any type of toner may be used as long as it can selectively supply toner of different colors to the photoreceptor drum 2.

The transfer belt 11 is used to transfer (secondary transfer) the toner image developed on the photoreceptor drum 2 by the developing devices 7 to 10 onto a paper surface material (hereinafter referred to as "paper") P on which a copy image is to be formed. The hook is passed around a plurality of rollers (not shown), and is supported by the photosensitive drum 2 so as to be rotatable in a counterclockwise direction while always being in contact with the photosensitive drum 2.

A transfer charger 12 for primary transferring a toner image from the photoconductor [ram 2] and a rotational position sensor 56 for detecting the rotational angular position of the transfer heald 11 are fixedly arranged inside the transfer heald 11. There is. Rotational position sensor 5
6 is a photosensor, and 1 on the inner surface of the transfer heald 11
A rotational position signal 310 is generated when the reflected light from the belt mark 57 provided at the location is sensed.

Further, around the outside of the transfer belt 11, a transfer charger 16 for secondarily transferring the toner image onto the paper P,
A separation charger 17 for separating the transfer belt 11 from the transfer belt 11 and a belt cleaner 15 for cleaning the outer surface of the transfer heald 11 are provided. The belt cleaner 15 can be selectively brought into contact with the transfer belt 11 (during cleaning) or separated.

An optical system 40 is arranged at the top of the color copying machine. The optical system 40 is located below the document platen glass 31 by an arrow M5.
A scanner 50 capable of reciprocating in the direction (forward direction) and arrow M6 direction (return direction), CCD for color editing
27 and lens 51 arranged nearby, a filter selection mechanism section 28 for enabling color separation exposure,
and a fixed mirror 29, and when the scanner 50 moves forward, it scans the document sheet and exposes the photosensitive drum 2.

The scanner 50 consists of a first slider 23 having an exposure lamp 24 and a mirror 41, and a second slider 52 having a mirror 42.43. For the speed V, v
The second slider 52 is driven by the scan morph 70 so as to move forward at a speed of /n (n is the copying magnification). The scanner home switch 71 is composed of a photo sensor, and outputs a signal indicating that the scanner 50 has returned to the reference position (home position) when the protrusion 73 of the first slider 23 faces the scanner home switch 71.

The filter selection mechanism section 28 includes a filter 28ND that performs total reflection, and three filter filters 28Y8, 28MG, and 28CR that are radially provided at an angle of 90 degrees to each other, with the shaft 28a as the center. By rotating and positioning the mirror 28a, one of these mirrors is selectively switched, and the selected mirror guides the scanning light to the exposure point of the photoreceptor drum 2 via the fixed mirror 29. has been done. A mirror reference position sensor 25 is located at the location where the selected mirror is positioned.
In Fig. 1, 2L-28ND is provided.
is shown selected and positioned.

Filter mirrors 28VB, 28MC, and 28CR are integrated mirrors and filters by depositing blue (B), green CG), and red (R) color separation filters on the mirror surface, respectively.
It is used corresponding to M and C color toners.

On the other hand, a paper cassette 32 that stores paper P is installed at the lower left side of the color copy @1, and a paper ejection tray 33 that stores the paper P on which a copy image has been formed is installed at the lower right side. There is.

The paper P is fed one by one from the paper cassette 32 by the paper feed roller 21, is conveyed by the timing roller 20 in alignment with the transfer heald 11, and after the toner image is secondarily transferred from the transfer belt 11, The image is sent to the fixing unit 19 by the transport heald 18 . A paper size sensor 13 for detecting the size of the paper P is provided near the paper feed roller 21, and a timing sensor 4 is provided near the timing roller 20 for detecting the leading edge position of the paper P passing therethrough. It is being

The fixing unit 19 includes a fixing roller 54, a fixing heater lamp 55 for heating, and the like, and fuses the toner image to fix it on the paper P. The paper P on which a copy image is formed by fixing the toner image is discharged onto the paper discharge tray 33 by a discharge roller 53 .

In addition, the main motor 2 is located in the center left side of the color copying machine 1.
2 are arranged, and the main motor 22 drives the above-mentioned photoconductor tram 2, transfer heald 1], paper feed roller 2j,
Timing roller 20. Conveyance heald 18, fixing roller 5
4, a paper ejection roller 53, and the like are rotationally driven.

In the color copying machine 1 configured as above, the above-mentioned Y
, M, C, and BK, and R(Y and M) G(
It is possible to form a composite monochrome copy image of Y and C), B (M and C), and a color (full color) copy image obtained by superimposing toner images of three primary colors.

In forming single toner color and composite monochrome copy images, the mirror 28ND is used to expose and scan the original, and the latent image formed on the photoreceptor drum 2 is developed in accordance with the specified color. The toner image is developed using any one of the containers 7 to 10 and transferred onto the transfer heald 11. Furthermore, in the case of a composite monochrome copy image, exposure scanning is performed again on the same original using the developer 28ND, and any one of the developing devices 7 to 10, which is different from the previous one for the bottom, is used. The developed toner image is transferred to a transfer belt 11, and the two color I/toner images are superimposed on the transfer belt 11.

In addition, a color copy image is obtained by scanning the same document multiple times according to a well-known color electrophotographic process, and filter mirrors 28YB, 28MG, 28C are scanned for each scan.
R and developing devices 7 to 9 are selectively switched to form and develop a latent image color-separated from the original, and the toner images are sequentially transferred to the transfer bell) 11, and the toner images of each color are It is formed by superimposing toner images.

When overlapping toner images (hereinafter referred to as "multiple transfer"), it is necessary to transfer each toner image to the same position on the transfer belt 11. Therefore, in the color copying machine 1 of this embodiment, the above-mentioned rotational position Rotational position signal S from sensor 56
The timing for starting the movement of the scanner 50, that is, the timing for starting the formation of a latent image on the photoreceptor drum 2, is controlled based on the IO generation timing.

FIG. 20 is a diagram showing how the photosensitive drum 2 is exposed.

In order to simplify the optical system 40, the color copying machine 1 uses a filter mirror 28Y828MG 28CR that integrates a mirror and a filter for color separation, as described above.
The filter selection mechanism section 28 is constructed by the filter selection mechanism section 28, and a filter that determines the optical path of the scanning light is movable.

For this reason, filter mirrors 28YB, 28MG28CR
Variations in the accuracy of mounting the filter mirrors onto the base, or filter mirrors 28YB, 28MG, and 28CR.

Due to variations in the stop position (stop angle) when switching the mirror 28ND, the four mirrors 28YB, 28MG
, 28CR, and 28ND may be misaligned in the exposure points on the photosensitive drum 2.

In the figure, as an example, the filter is 28YB.
Each exposure point θyθm of 28MG is shown.

3 In the case where a shift occurs in the exposure point, if the start timing of each scan with respect to the above-mentioned rotational position signal SIO is the same, the transfer position of each toner image to the transfer belt 11 will shift, causing color shift in the copied image. The image quality will deteriorate.

Therefore, in the color copying machine 1, the rotational position signal SI
The scan start timing for each mirror 28YB,
It is said that it can be adjusted for each 28MG, 28CR, and 28ND.

In the following explanation, the mirror 28ND, filter mirrors 28YB, 28MG, and 28CR are used as ND filter, B filter, G filter, and R filter, respectively, based on color separation characteristics.
Sometimes called a filter.

FIG. 2 is a plan view of the operation panel OP provided on the top surface of the color copying machine 1.

On the right side of the operation panel OP, there are a print key 200 for starting the copying operation, a numeric keypad 202 for setting copying conditions such as the number of copies, a 7-segment LED 201 for displaying the number of copies, and a clear/stop key 20.
3. Interrupt key 204, magnification up and magnification down keys 205, 206 for setting the copy magnification, 3-digit 7-segment LED 207 for displaying the copy magnification, amplifier and step-by-step manual setting of the density of the copy image. Keys and display LEDs used in normal copying operations, such as down keys 210 and 208, an LED 21 for displaying the density level of the copied image, an auto density setting key 209, and an auto density display LE0222 are arranged.

Also, on the left side of the operation panel OP are Y and M.

LED 223 that indicates the shortage of toner for each color of C and BK
Y, 223M, 223C, and 2238, an LED 224a that displays whether the waste toner storage container is full, an interrupt display LED 224b, and a paper P jam display LED 224.
c. Each color (Y
, M, C, R, G.

Color keys 225 to 231 corresponding to B, BK), full color key 232.0 for specifying color copying
OHP key 233 used when paper P is a transparent sheet for P (Over-Head Projector), etc.;
Book 7 key 234 used when copying the left and right pages of a spread of a book or the like on two sheets of paper P, and display LEDs corresponding to each of the keys 225 to 234.
235 to 244 are arranged.

In addition, in the following explanation, color keys 225, 226.2
27, 228, 229, 230, and 231 are sometimes referred to as the Y key, M key, C key, R key, C key, B key, and BK key, respectively.

FIG. 3 is a block diagram of the control circuit 400 of the color copying machine 1.

The control circuit 400 includes a CPU that controls the overall operation of the color copying machine 1 (a central processing bag 401, a scan morph control 452 that controls the drive of the scanner 50, and a control circuit that controls the movement of the main lens 26 in accordance with the copying magnification). It is mainly composed of a lens motor control 453 and a filter mirror motor control 454 that performs switching control of the filter selection mechanism section 28.

A switch matrix 450 in which various operation keys on the operation panel OP, toner empty sensors 7a to 10a, etc. are arranged vertically and horizontally is connected to the CPU 401.

The 7-segment LED 201 and display LEDs related to operation mode and color designation are connected via the switch matrix 450 and decoder 451, and their lighting or extinguishing is controlled.

Further, the output signals and rotational position signal SIO of the vapor size sensor 13 and the timing sensor 14 described above are input to the input terminal of the CPU 401, and the signals are connected to the output terminal based on the signals from each of these sensors and the switch matrix 450. The main motor 22, various clutches such as a developing clutch, each charger, the exposure lamp 24, etc. are controlled to be turned on or off.

Furthermore, the CPU 401 includes a B filter, a G filter,
Three sets of dip switches 455, 456, and 457 are connected to adjust the above-mentioned deviation of the exposure point when the R filter is selectively switched and used. That is, the scan start timing for forming each of the three Y, M, and C toner images can be changed in eight steps with respect to the generation timing of the rotational position signal Sho.

As a result, in the color copying machine 1, the exposure points corresponding to the B filter, G filter, and R filter can be corrected so as to match the exposure points of the reference ND filter, and high quality images without color shift can be achieved. It becomes possible to form a color copy image.

Next, the operation of the color copying machine 1 will be explained with reference to flowcharts shown in FIGS. 4 to 18.

FIG. 4 is a main flowchart schematically showing the operation of the CPU 401.

When the power is turned on and the program starts, first,
In step #1, registers and peripheral interfaces are initialized, and in step #2, an internal timer for defining the length of one routine of the CPU 401 is set.

In step #3, manual key processing is performed to receive and receive signals from the operation keys of the operation panel OP, and in step #4, a display process for displaying on the operation panel OP is executed.

Next, paper feeding/feeding processing (step #5) that controls the paper feeding and transport of paper P, image creation processing (step #6) related to the electrophotographic process, and scanning for scanning the original document. A series of copy sequence processes consisting of the process (step #7) is executed.

After executing these processes, an internal timer is waited in step #8, and the process returns to step #2. As a result, the length of one routine is kept constant, and each process from step #2 to step #8 is repeated while the power is turned on.

FIG. 5 is a flowchart of the key manual processing in step #3.

Steps #11 to #18 are key processes corresponding to the operation keys for specifying the color of the copy image, and in each step, the monocolor mode for each single toner color of Y, M, and C, R , G, B each composite monocolor mode,
Full color mode and BK monocolor mode (corresponding to black and white copying) are set.

In step #19, OHP key processing is performed, and in step #20, other key processing is performed.

FIG. 6 is a flowchart of the Y key processing in step #11.

First, in step #26, it is checked whether or not the Y key 225 has been pressed (hereinafter referred to as "on-check"), and if no, the process returns directly.

If YES in step #26, in step #27,
An empty check is performed to determine the presence or absence of Y toner (whether there is a shortage or not), and if YES, the process returns directly. If no in step #27, that is,
If Y toner is present, in step #28, a Y copy mode is set in which monochrome copying is performed using only Y toner.

Although not shown, in the M key processing and C key processing in steps #12 and #13 in FIG. If the check conditions are satisfied, M copy mode or Y copy mode is set.

FIG. 7 is a flowchart of the R key processing in step #14 of FIG.

First, in step #30, an on-check of the R key is performed, and if YES, an empty check of the Y toner is performed in step #31.

If there is Y toner, an empty check of M toner is performed in step #33. If both Y toner and M toner are present, in step #35, an R copy mode is set in which the Y toner image and the M toner image are superimposed.

On the other hand, if it is determined that there is no Y toner in the check in step #31, an empty check is performed for the M toner in step #32, and if there is M toner even though there is no Y toner, the M toner is checked in step #34. Set the M copy mode, which performs monochrome copying using only toner.

In other words, since R (red) and M (magenta) are visually similar colors, R
Even if coloring is not possible, the M copy mode is set as an alternative to the R copy mode without ignoring the press of the R key. If both Y toner and M toner are empty, no copy mode is set even though the R key is pressed.

FIG. 8 is a flowchart of the C key processing in step #15 of FIG.

First, in step #40, an on-check of the G key is performed, and if YES, an empty check of the Y toner is performed in step #41.

If there is Y toner, an empty check of C toner is performed in step #42. If both Y toner and C toner are present, in step #43, a C copy mode is set in which the Y toner image and the C toner image are superimposed.

On the other hand, if the answer is YES in step #40 and step #41, the process returns without setting the copy mode.

B That is, G (green) and Y (yellow), and G and C
(cyan) is not considered a similar color to -i, so G
It is not possible to use a single color of Y or C as an alternative. Therefore, if either the Y toner or the C toner is in short supply, no copy mode is set for either color.

FIG. 9 is a flowchart of the B key processing in step #16 of FIG.

First, in step #50, the B key is checked, and if YES, an empty check of the C toner is performed in step #51.

If there is C toner, an empty check of M toner is performed in step #52. If both C toner and M toner are present, in step #54, a B copy mode is set in which the C toner image and the M toner image are superimposed.

If YES in step #52, that is, if there is C toner and there is no M toner, then in step #53, C toner is present and M toner is absent.
Set the C copy mode, which performs monochrome copying using only toner.

In other words, since B (red) and C are visually similar colors, even if it is impossible to color B due to a lack of M toner, you can use the B copy mode without ignoring the press of the B key. C copy mode is set as an alternative.

FIG. 10 is a flowchart of the full color key processing in step #17 of FIG.

First, in step #60, the full color key 232 is checked, and if YES, an empty check is performed for each of Y, M, and C toners in sequence in steps #61 to #63.

If all Y, M, and C toners are present, step #
At 64, a full color mode is set in which Y, M, and C toner images are superimposed.

If even one color of toner among Y, M, and C is insufficient,
Since it is impossible to form a color copy image, the process returns without setting the full color mode.

FIG. 11 is a flowchart of the BK primary key processing in step #18 of FIG.

First, in step #70, the BK key is checked, and if YES, an empty check of the BK key is performed in step #71.

BK) If there is a ner, in step #76,
Set the BK copy mode that performs monochrome copying using only BK color.

On the other hand, in the case of YES in step #71, the empty check of each toner of YlMC is sequentially executed in step gaff 2 to step knob #74.

If you have all YMC toners, use stencil #75.
, Y and M were formed sequentially using mirror 28ND.
, C toner images are superimposed.

In other words, in the color copying machine 1, in addition to the three primary color toners for forming color copy images, if there is a shortage of BK toner, which is mainly provided for forming black and white copy images, black and white copies will be made. As an alternative, toners of the three primary colors may be used to form a black and white copy image without prohibiting the above.

1. FIG. 12 is a flowchart of the OHP key processing in step #19 of FIG.

First, in step #80, the OHP key 233 is turned on. If YES in step #80, then in step #81 it is checked whether the OHP mode has already been set.

If YES in step #81, ○ in step #82.
Cancel HP mode, and if no in step #81,
In step #83, the OHP mode is set.

Here, the OHP mode is an operation mode in which the system speed of the entire electrophotographic process is made slower than in the normal operation mode.This increases the time it takes the paper P to pass through the fixing unit 19, and The toner images are sufficiently melted and mixed, and the translucency of the color copy image is enhanced.

In addition, in the color copying machine 1 of this embodiment, when returning from the OHP mode to the normal operation mode, a timer is provided to measure a predetermined time, and a timer is provided to wait for the state of each part related to the electrophotographic process to stabilize. The apparatus is configured to start the operation associated with the electrophotographic process after the electrophotographic process, thereby avoiding disturbances in the copied image due to poor cleaning or poor toner agitation, or automatic stopping of the system due to detection of defects.

FIG. 13 is a flowchart of the display processing of step #4 in FIG.

In step #90, toner empty sensors 7a to 1
Based on the signal from 0a, execute toner empty processing to display the shortage of each toner on the operation panel OP,
In step #91, a color specification display process is executed to display a copy image in accordance with the color specification.

After executing these processes, other display processes are performed in step #92.

FIG. 14 is a flowchart of the toner empty processing in step #90.

First, in step #100, an empty check of the Y toner is performed. If YES in step #100, the LED 223Y is turned on in step #101, and if NO in step #100, the LED 223Y is turned on in step #102.
Turn off 223Y.

Similarly, in step #103, perform an empty check on M+-ner, and if YES, step #104
Turn on L E D 223 M at step #10
If 3 is no, L E D at step #105.
223 Turn off M.

Next, in step #106, an empty check of the C toner is performed, and if YES, the LED 223C is turned on in step #107, and if NO in step #106, the LED 223C is turned off in step #108.

Finally, in step #109, perform an empty check on the BK)ner, and if YES, turn on the LED 223BK in step #110, and if NO in step #109, turn off the LED 2238K in step #111. .

FIG. 15 is a flowchart of the color designation display process in step #91 of FIG.

In this routine, first, in steps #120 to #125, a check is sequentially executed to determine whether a copy mode corresponding to each monochrome color of Y, M, C, R, G, and B is set.

If the answer is YES in each of steps #120 to #125, steps #26 to #1 are displayed to indicate that each copy mode has been set.
31, the LEDs 235 to 240 are turned on, respectively.

If the answer is NO in any of steps #120 to #125, the process moves to step #132 and checks whether the full color mode is set. If step #132 is YES, step #135 turns on the LED.
242 is lit.

If the result in step #132 is NO, it is checked in step #133 whether the BK copy mode is set or not. If the result is YES, in step #136, the LED 2
41 is lit.

Also, if no in step #133, step #1
At step 34, a check is made to see if the 3-color overlapping mode is set, and if yes, at step 5, the LED 241 is blinked at block #137.

If the LED 241 flashes, the operator should
It is determined whether or not the color overlapping mode is acceptable, and if it is acceptable, the print key 200 is pressed to start printing. If not, replenish the black toner and then specify the BK all mode again. In other words,
In the color copying machine 1, when there is a shortage of black toner, the operator selects whether to combine three primary color toners to form a black copy image or to form a black copy image using the black toner after replenishment. can do.

FIG. 16 is a flowchart of the paper feeding/paper passing process in step #5 of FIG.

In this routine, first, in step #140, the state indicated by the current state counter is checked, and the following processing is executed depending on the state.

In the initial state immediately after the power is turned on and in the standby state after the copying operation is completed, the state is rQJ.

In state "0", first, in step #141, the print key 200 is pressed, and if the answer is NO, the process returns to the main routine.

If YES in step #141, step #142
The main motor 22 is turned on to start rotating each part.

Next, in step #143, the main motor start-up timer for waiting for the rotation of the main motor 22 to stabilize is set to seven, and in step #145, the state is set to "1".

In state "1", the main motor start-up timer is counted up in step #150. As a result, each time step #150 is executed, the count number of the main motor start-up timer is updated, and timekeeping progresses.

In the following step #151, it is checked whether the count number of the main motor start-up timer has reached a predetermined value, that is, it is confirmed that the timer has finished counting, and if no, the process returns, and if YES in step #151, In step #152, the state is updated to "2".

In state "2j", in step #160, the paper feed roller 21 is turned on to feed the paper P into the conveyance path, and the state is set to "3" (step #161).

In state "3", the timing sensor 14 is checked in step #170.

If YES in step #170, step #171
Turn off the timing roller 20 and continue with step #17.
Step #2 sets a paper loop timer for registration alignment, and step #173 sets the state to "4".

In state "4", the paper loop timer is counted up in step #■80, and step #
At step 181, the end of the paper loop timer is confirmed.

If step #181 is YES, step #182
Turn off the paper feed roller 21 and set the state to "5" (
Step #183).

In state "5", it is determined in step #190 whether or not it is the timing to register the paper P with respect to the toner image on the transfer heald 11.

If YES in step #190, the timing roller 20 is turned on to advance the conveyance of the paper P (step #19
1).

In the following step #192, it is checked whether the mode is OHP mode or not. If it is the OHP mode, it is necessary to reduce the speed at which the paper P passes through the fixing unit 19, so the process moves to step #195 and the state is changed to " 9”.

If the answer in step #192 is NO, set the paper feed interval timer to "6" (step #193) to keep the distance between each sheet of paper P constant in the transport path (step #193).
Stembu #194).

In state "6", the paper feed interval timer is counted up in step #200, and the count-up is performed in step #20.
Step 1 confirms that the paper feed interval timer has ended. If the paper feed interval timer has ended, the state is set to “
7”.

In state r7j, in step #210, it is checked whether multi-copying in which the number of copies is two or more is specified by the operation panel OP.

In the case of multi-copy, the state is returned to "2" in step #211, and in the case of single copy where the number of copies is one, the state is updated to "8" in step #212.

In state "8", wait until all the fed sheets P are ejected to the paper ejection tray 33, and proceed to step #22.
0, and when completion of paper ejection is confirmed based on a signal from a paper ejection sensor (not shown), the main motor 22 is turned off in step #221 and the state is returned to "0" (step #221).
222).

If the OHP mode is determined in step #192 of state "5" described above, the processes of states "9" to "11" are executed.

In state "9", first, in step #230, it is checked by process tying whether the toner image of one color or a plurality of colors has been secondarily transferred from the transfer belt 11 to the paper P.

If YES in step #230, step #131
As described above, in order to lengthen the passage time (heating time) of the paper P through the fixing unit 19, the fixing roller 54 is
The rotational speed of the main motor 22 that drives the main motor 22 is reduced.

Note that it is also possible to maintain the rotational speed of the main motor 22 at a normal speed and reduce only the rotational speed of the fixing roller 54 using a clutch or the like.

After that, in step #232, the state is set to "10".

In state "10", in step #240, it is confirmed that the OHP paper P that has passed through the fixing unit 19 at low speed is ejected, and in step #241, the rotational speed of the main motor 22 is returned to the normal speed. do.

Next, in step #242, a process stability timer is set to wait for the state of each part related to the electrophotographic process to become stable, and in step #243, the state is changed to "
11”.

In state "11", the process stability timer is counted up in step #250, and the end of the process stability timer is confirmed in step #251.

If step #251 is YES, step #522
Returns the state to "7" and returns to the main routine.

FIG. 17 is a flowchart of the image forming process in step #6 of FIG.

First, in step #300, the state is checked, and the following processing is executed according to each state from state "20" to state "35".

In state "20", first, print key 20 is pressed.
0 is checked (step #301).

If step #301 is YES, follow step #3
At step 02, the charger 5, main routine amplifier 4, etc. are turned on to prepare for the electrophotographic process.

Next, in step #303, the copy number counter is set to "0".
” and advance the state to “21”. The copy number counter is for counting the number of secondary transfers from the transfer hold 1 to the paper P.

ST) r2], J, in step #311,
Check whether the mode for multiple transfer is set.

If no in step #311, that is, if a copy image is to be formed with one color toner, stencil #3
Proceed to step 12.

On the other hand, when performing multiple transfer, it is necessary to perform multiple scans in synchronization with the rotation of the transfer belt 11, so the state is advanced to "26" in step #315.

In step #312, the filter selection mechanism section 28 selects N.
Select the D filter to define the optical path for exposure.

Next, in step #313, the heald cleaner 15 is turned on to clean the transfer heald 11, and the state is advanced to "22" (step #314).
.

In state "22", the exposure lamp 24 is turned on (step #321), the developing clutch of any one of the developing devices 7 to 10 is turned on (step #322) according to the set copy mode, and the exposure lamp 24 is turned on (step #322). Set the exposure lamp start-up timer to wait for the light amount to stabilize (step #323), and set the state to "23" (step #323).
Step #324).

In state "23", the exposure lamp rising timer is counted up in step #331, and the completion of the exposure lamp rising timer is confirmed in step #332.

If YES in step #332, step #333
Then, a scanner start signal S20 for starting the forward movement of the scanner 50 is output, and the state is set to "24" in step #334.

In step) r24J, the completion of scanning is confirmed in step #341, and if YES, the exposure lamp 24 is turned off (steer knob #342), and the developing clutch that was previously turned on is turned off (step #342). 343).

Next, in step #344, it is checked whether or not it is multi-copy, and if it is multi-copy, step #34 is executed.
5, the state is set to "25", and in the case of single copy, the state is returned to the initial value "20" in step #346.

In stay 1-r25J, stencil #351,
It is checked whether the return of the scanner 50 has been completed, and if the return has been completed, the state is set to "22" in step #352.

As mentioned above, step #31 of stay 1-r21J
If it is determined that the mode is multiple transfer in step 1, the processes in states "26" to "35" are executed.

In state r26J, the number of colors to be combined is checked in step #361.

If there are two colors in step #361, composite monochrome (R
, G, B), select the ND filter (step #362), set the scan counter to "2" which indicates the number of scans for one copy image (step #363), and set the state to "27". ” (Step #364).

On the other hand, if there are 3 colors in step #261, step #3
65 to check whether the mode is full color mode.

In the case of full color mode, the B filter is selected in order to form a Y toner image first (step #366); in the case of not the full color mode, that is, in the case of three-color superimposition mode, the ND filter is selected (step #366). 368)
.

After executing step #366 or step #368, in step #367, the scan counter is set to "3" and the state is updated.

In stay 1-r27J, in step #371,
It is checked whether the rotational position signal SIO has been generated, that is, whether the belt mark 57 of the transfer belt 12 has been detected. If YES in step #371, an exposure lamp on timer for determining the lighting timing of the exposure lamp 24 is set in step #372, and the state is advanced to "28" (step #373).

That is, the transfer heald 11 is rotationally driven at a constant speed, and the period of generation of the rotational position signal 310 is constant. Therefore, in the color copying machine 1, in a scan that is started based on the generation timing of the rotational position signal Sho,
In order to keep the light amount of the exposure lamp 24 stable, an exposure lamp on timer is provided to turn on the exposure lamp 24 at a certain time based on the generation timing of the rotational position signal 310 immediately before the start of scanning. ing.

This makes it possible to prevent unnecessary lighting of the exposure lamp 24 and to prevent scanning when the amount of light is unstable.

In state r28J, the exposure lamp on timer is counted up in step #381, and the end of the exposure lamp on timer is confirmed in step #382.

7. If YES in step #382, turn on the exposure lamp 24 (step #383), turn on the developing clutch (step #384), and set the state to "29" (step #385).

In state "29", the presence or absence of the rotational position signal 310 is checked in step #39■.

If YES in step #391, the exposure lamp on timer is set in step #392 in order to determine the lighting timing of the exposure lamp 24 in the second and subsequent scans in the same way as described above, and in step #393, the scanner A start signal S20 is output. After that, the state is set to 130'' (step #394).

In state "30", first step #40
In step 1, the completion of scanning is confirmed.

If the scan is completed, the subsequent steps #402 to #415 are executed.

That is, the exposure lamp 24 is turned off (step #402L).
After turning off the developing clutch during driving (step #403) and counting down the scan counter (step #404), check whether the scan counter is "0" (step #404). 405).

If YES in step #405, it means that the copying operation for one sheet of paper P has been completed, so step #405
At step 06, a count amplifier is performed to calculate the number of copies.

Next, in step #407, it is checked whether the value of the copy number counter has reached IO or not, and if no,
Proceed to step #415 and advance the step to "34".

If YES in step #407, reset the copy number counter (step #408), turn on the belt cleaner 15 (step #409), and time the cleaning time (one rotation time of the transfer bell 11). Cent of Heald Cleaning Timer (Step #410)
) in sequence, in step #411 the state is changed to “
Proceed to "33".

In other words, when multi-copy is specified, in the mode that performs multiple transfer, that is, full color mode, composite color (R, G, B) copy mode, and 3-color overlapping mode, the same copy on the transfer bell) 11 Multiple sheets of paper P at the position
A toner image corresponding to each of the images is formed. Therefore, even if some toner remains on the transfer belt 11 after the secondary transfer, the effect on the next sheet P is small.
Although it is not necessary to clean the transfer belt 11 for each sheet of paper P, if residual toner accumulates, there is a risk that the quality of the copied image will deteriorate. Therefore, in the color copying machine 1, the number of secondary transfers is counted by a copy number counter, and
The electrophotographic process is interrupted every 10 sheets of paper P, and the transfer belt 11 is cleaned.

On the other hand, if the answer in step #405 is NO, the process proceeds to step #412, where it is checked whether the mode is full color mode.

If it is not the full color mode, the state advances to "31" in step #414. In the case of full color mode, in step #413, the filter is switched to select a G filter or an R filter depending on the color of the toner image to be formed next, and then the process proceeds to step #414.

In state "31", in step #421, it is checked whether scanning is possible every time the rotational position signal SIO is generated, with reference to a scan table TS, which will be described later, related to paper size and copying magnification.

If YES in step #421, follow step #4
At step 22, in order to determine whether scanning is possible each time the rotational position signal SIO occurs in connection with the book mode, it is checked whether the next scan is a scan of 1798 pages.

1798 plane means the scanning direction (M
5) When the document sheet is divided into two sides using the center as a boundary, this is the side farthest from the home position of the scanner 50. Note that the nearer side is the book A side, and in the book mode, the book A side and the 1798th side are each copied onto separate sheets P.

If no in step #422, step #423
The state is returned to "28" and the next lighting timing of the exposure lamp 24 is waited.

Also, if step #421 is NO and step #4
If the answer is YES in step #424, the state advances to "32".

In state "32", in step #431, it is checked whether the rotational position signal SIO is generated.

If YES in step #431, step #432
After setting the exposure lamp on timer, the scan start signal S20 is activated, unlike the state "29" described above.
The state is returned to "28" in the following step #433 without outputting.

That is, in this case, the rotational position signal SIO is invalidated with respect to the start of the scan.

FIG. 19 is a diagram showing the contents of scan table TS.

The scan table TS determines in advance the reciprocating time of the scanner 50 determined by the mutual relationship between the size and paper feeding direction of the paper P on the document table glass 31 and the copying magnification set by the numeric keypad 202, etc., and starts scanning. The number of occurrences of the rotational position signal 310, which is a necessary condition for
” or “2j)” is stored as data.

In the notation of paper size in the same figure, for example, A3
@1 refers to the case where A3 size paper P is fed with its longitudinal direction as the transport direction, and A4 landscape refers to the case where A4 size paper P is fed with its longitudinal direction perpendicular to the transport direction. means.

In the color copying machine 1, the circumference of the transfer belt 11 is 450 mm.
mm, and the system speed in normal operating mode is 110 mm/sec.

Therefore, the time for one rotation of the transfer belt 11 (the period of generation of the rotational position signal SIO) is 4.09 seconds.

On the other hand, in the scanner 50, the time required for reciprocating movement consisting of acceleration, constant speed, and deceleration periods is, for example, 3.5 seconds when making a full-size copy using A4 landscape paper P. 0 second (2.2 seconds for forward movement, 0°8 seconds for backward movement), and in this case, since the movement time is shorter than the generation cycle of signal S10, every time the signal 310 occurs (1 transfer heald Scanning can be started continuously after each rotation.

On the other hand, even when copying at the same size, in the case of A3 portrait paper P, the reciprocating time of the scanner 50 is 5
．． 4 seconds (4.2 seconds for forward movement, 1.2 seconds for backward movement), which is longer than the generation cycle of signal SIO, so scanning cannot be started continuously every time signal SIO occurs. Therefore, in this case, signal SIO is invalidated every other time of its occurrence, as described above, and scanning is started every second occurrence of signal 310.

Further, even when using paper P of the same size, the reciprocating time differs depending on the copying magnification.

In other words, the scan table TS generates a rotational position signal, which is a condition for starting scanning, in association with a copying condition consisting of the size and feeding direction of the paper P on the document table glass 31, and the copying magnification set by the numeric keypad 202, etc. The number of occurrences of SIO ("1" or "2") is determined in advance.

Returning to FIG. 17, in state "33", the belt cleaning timer is counted up in step #441, and the end of the heald cleaning timer is confirmed in step #442.

If YES in step #442, step #443
Turn off belt cleaner 15 and repeat step #40 above.
The cleaning of the transfer belt 11 started in step 9 is completed.

Thereafter, in step #444, the state is updated to "34".

In state "34", in step #451 it is checked whether there is a copy request prompting the next copying operation, and if there is no copy request, the process moves to step #453 and the state is returned to the initial value "20".

As a result, the color copying machine 1 enters a standby state.

If there is a copy request, the state is advanced to "35" in step #452.

5 In state 35J, in step #461, it is checked whether the return of the scanner 50 has been completed.

If YES in step #461, step #1 is returned to 126'' in step #462 in order to proceed to the next copying operation.

FIG. 18 is a flowchart of the scan process of step #7 in FIG. 4.

First, in step #500, the state is checked, and the following processing is executed according to each state from state "40" to state "43".

In state "40", first, step #501
Check the presence or absence of the scanner start signal S20,
If yes, proceed to step #502.

In step #502, the optical system 40 checks the filter selected in accordance with the toner color, and subsequent processing branches depending on the filter.

If an ND filter is selected, step #5
The program advances to 03, updates the state to "41", and returns.

If the B filter is selected, before the state update, in step #504, a B delay timer is set with a clock time set based on the timing correction by the dip switch 455 described above.

Further, if the G filter is selected and the R filter is selected, step #50 is performed, respectively.
5. Proceed to step #506, and in each step, the state is updated after setting the G delay timer and the R delay timer whose clock times are set by dip switches 456 and 466.

In state "41", in step #511, the set delay timer is counted up,
In step #512, the end of the delay timer is confirmed.

If step #512 is YES, step #513
Then, the scan motor 70 starts forward movement of the scanner 50, and the state is set to "42".

Note that in step #512, if the ND filter is selected, it is assumed that the timer has ended, and the answer is YES.

In state "42", it is determined in step #521 whether or not the scanner 50, which is moving forward, has reached the rear end of the document tray and has finished scanning.

If the scanning is completed, the scanner 50 starts returning at step #522 and advances the state to "43" (step #523).

In state "43", the scanner 50 waits for the return to the home position, and when the completion of the return is confirmed in step #524, the state is returned to the initial value "40" in step #525.

According to the embodiment described above, when switching from the OHP mode for increasing the translucency of the copied image to the normal copying mode, the electrophotographic process is stopped until a predetermined period of time has elapsed for the state of each part to stabilize. In the above-described embodiment, it is possible to form high-quality copied images under stable process conditions.
A transfer belt 11 as an intermediate transfer medium is placed between the paper P and the paper P.
The color copying machine 1 has been exemplified using an intermediate transfer method in which toner images of each color are superimposed on a transfer heald 11. or a method performed on a photoreceptor drum (for example, Japanese Patent Laid-Open No. 61-32854)
The present invention can also be applied to a color copying machine that employs the above-mentioned color copying machine.

〔Effect of the invention〕

According to the first aspect of the invention, it is possible to form a high-quality color copy image without misalignment of toner images.

According to the second aspect of the invention, it is possible to provide a color copying machine that can increase the number of copies of monochrome images per unit time.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional front view showing the general configuration of a color copying machine;
FIG. 2 is a plan view of the operation panel provided on the top of the color copying machine, and FIG. 3 is a block diagram of the control section of the color copying machine.
4 to 18 are flowcharts showing the operation of the color copying machine, FIG. 19 is a diagram showing the contents of the scan table,
FIG. 20 is a diagram showing how the photosensitive drum is exposed. DESCRIPTION OF SYMBOLS 1... Color copying machine, 7-10... Developing device (developing device means), 11... Transfer belt (rotating body), 24...
Exposure lamp, 50...Scanner, 56...Rotational position sensor (rotational position detection means L401...CPU (
Exposure lamp control means), D... Original, SIO... Rotational position signal.

Claims (2)

[Claims] (1) A scanner that moves back and forth to scan a document; an exposure lamp built into the scanner to irradiate the document; and an exposure lamp that irradiates the document with a predetermined amount of light when the scanner moves forward. an exposure lamp control means for turning on the lamp and turning off the exposure lamp when the forward movement of the scanner is completed; a plurality of developing means for forming toner images; a rotary body that rotates in response to scanning in order to superimpose the toner images; and a rotational position detection means that generates a rotational position signal for each rotation of the rotary body. A color copying machine capable of forming a color copy image by sequentially forming toner images of each color on the same document by the plurality of developing means and superimposing them on the rotary body, When forming a color copy image,
A plurality of scans of the same document are started based on the rotational position signal, and the lighting timing of the exposure lamp for the second and subsequent scans of the same document is determined by the rotation corresponding to the start of the previous scan. A color copying machine characterized in that the determination is made based on a position signal. (2) a scanner that moves back and forth to scan a document; an exposure lamp built into the scanner to irradiate the document; and an exposure lamp that irradiates the document with a predetermined amount of light when the scanner moves forward. an exposure lamp control means for turning on the lamp and turning off the exposure lamp when the forward movement of the scanner is completed; a plurality of developing means for forming toner images; a rotary body that rotates in response to scanning in order to superimpose the toner images; and a rotational position detection means that generates a rotational position signal for each rotation of the rotary body. a color copy image in which toner images of each color are sequentially formed on the same original by the plurality of developing means and superimposed on the rotating body;
In a color copying machine capable of selectively forming a monochrome copy image using only two developing means, when forming the color copy image, scanning the same original document multiple times based on the rotational position signal. The color copying machine is characterized in that the scanning of the original is started at a timely manner, regardless of the rotational position signal, when forming the monochrome copy image.