JPH03186864A - Color copying machine - Google Patents

Abstract

PURPOSE:To miniaturize a rotating body and to increase the number of copied sheets per unit time while the aligning accuracy of a toner image is maintained by starting scanning every generation time of a rotational position signal which is generated previously fixed times according to the back and forth moving time of a scanner in one scanning. CONSTITUTION:The rotating body 11 is rotated corresponding to the scanning in order to superpose the respective toner images. A rotational position detection means 56 generates the rotational position signal every time that the body 11 is rotated once. Besides, a scanning control means starts the forth movement of the scanner 50 based on the rotational position signal. Then, when the plural times of the scanning are executed for an identical original, the scanning is started every generation time of the rotational position signals which is generated previously fixed times according to the back and forth moving time of the scanner 50 in one scanning. Thus, the rotating body for superposing the toner images is miniaturized and the number of the copied sheets per unit time is increased while the aligning accuracy of the toner image is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color copying machine that forms a color copy image by superimposing toner images of each color.

[Conventional technology]

A color copying machine using an electrophotographic process generally forms a color copy image corresponding to a document by superimposing toner images of three primary colors, cyan (C), magenta (M), and yellow (Y).

The most common method for forming color copy images is to superimpose toner images on copy paper wrapped around the circumferential surface of a rotating transfer body. A method in which toner images are superimposed and then transferred to copy paper all at once, or a method in which toner images are superimposed on a photoreceptor and then transferred to copy paper (for example, Japanese Patent Laid-Open No. 6
1-32854).

In either method, the circumferential surface of the rotating body (photoreceptor or transfer rotating body) for superimposing each toner image has a width and length that corresponds to the maximum size of copy paper applicable to the color copying machine. have.

On the other hand, a document placed on a document table is scanned when a scanner, which is capable of reciprocating in parallel with the placement surface, moves forward.

In a conventional color copying machine configured to expose a photoreceptor to scanning light from an original, for example,
As shown in Japanese Patent No. 37505, a rotational position sensor is provided to detect the rotational angular position of a transfer rotor that is rotationally driven in response to scanning, and the rotational position is determined every time the transfer rotor rotates once. Movement of the scanner is controlled based on the rotational position signal generated by the sensor.

That is, by starting scanning in synchronization with a rotational position signal that is generated at regular intervals, timing control for positioning (registration) of each toner image on the rotating body is performed.

[Problem to be solved by the invention]

When forming a color copy image, the same document is scanned three or four times in succession to form toner images of each color. In addition, so-called continuous copying (multi-copying) in which multiple copies of the same original are formed, and copying in which the original is divided into two parts in the scanning direction, one on the front side and the other on the rear side, on two sheets of copy paper. Even in book division copying and the like, scanning of the same document is performed continuously.

However, in conventional color copying machines, scanning is started every time the above-mentioned rotational position signal is generated, so when scanning is performed continuously, the generation cycle of the rotational position signal, that is, the rotating body rotates once. During this time, the scanner must complete its forward and backward movements.

In other words, the generation cycle of the rotational position signal must be longer than the time required for the scanner to move back and forth. For this reason, there was a problem in that it was necessary to provide a large rotating body with a long circumference.

Further, the time required for the reciprocating movement of the scanner varies depending on the size of the document, copying magnification, forward scanning or backward scanning in book division, and the like.

Therefore, if the generation cycle of the rotational position signal is set to correspond to the copy mode in which the scanner's reciprocating time is the longest among the various copy modes, in the copy mode in which the reciprocating time is short, the reciprocal movement will end. There is a waiting time from the time to the generation of the next rotational position signal, resulting in a problem that the index (number of copies) indicating the number of copy images that can be formed per unit time decreases.

In view of the above-mentioned problems, the present invention provides a color copying machine that reduces the size of the rotating body for overlapping toner images and increases the number of copies per unit time while maintaining the accuracy of toner image alignment. is intended to provide.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a scanner that moves back and forth to scan an original, and a toner that develops a latent image formed by scanning the original using toner of a different color. a plurality of developing means for forming images; a rotary body that rotates in response to scanning in order to superimpose the respective toner images; and a rotational position detection means that generates a rotational position signal for each rotation of the rotary body; scanning control means for starting forward movement of the scanner based on the rotational position signal, and scanning the same document multiple times;
In a color copying machine that forms a color copy image by sequentially forming toner images of each color for each scan and superimposing them on the rotating body, when scanning the same document multiple times, 1 The present invention is characterized in that scanning is started every time the rotational position signal is generated a predetermined number of times depending on the reciprocating time of the scanner in one scanning.

[For production]

In the scanner, a plurality of developing means move back and forth to scan an original, each developing a latent image formed by scanning the original using toner of a different color 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.

The scanning control means starts forward movement of the scanner based on the rotational position signal.

When scanning the same document multiple times, scanning is started every time the rotational position signal is generated a predetermined number of times depending on the reciprocating time of the scanner in one scan.

〔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 belt 11 as an intermediate transfer medium are provided. The photosensitive drum 2 has 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 a latent image is generated by an optical system 40, which will be described later. exposed to light.

Each developing device 7, 8, 9.10 has yellow (Y)
), magenta (M), cyan (C), black (BK)
Toner empty sensors 7a and 8a are used to detect the shortage of toner of each color.
, 9a, and 10a are provided.

Note that the developing units 7 to 10 are not limited to a type in which they are fixedly arranged around the photosensitive drum 2, but may be, for example, in a type in which the developing units 7 to 10 are integrated and movable in the vertical direction. 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 units 7 to 10 onto a paper surface material (hereinafter referred to as "paper") P on which a copy image is to be formed. The photosensitive drum 2 is held by a plurality of rollers (not shown), and is supported 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 photosensitive drum 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. . Rotational position sensor 5
A photo sensor 6 generates a rotational position signal SIO when it senses reflected light from a heald mark 57 provided at one location on the inner surface of the transfer belt 11.

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 heat cleaner 15 for cleaning the outer surface of the transfer belt 11 are provided. The belt cleaner 15 can be pressed into contact with the transfer belt 11 (during cleaning) or separated.

At the top of the color copying machine 1, an optical system 40 is arranged. 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 4243. When scanning an original document, the first slider 23 is moved at a peripheral speed V of the photoreceptor drum 2. On the other hand, v/
The second slider 5 moves forward at a speed of n (n is the copying magnification).
2 is driven by a scan motor 70 so as to move forward at a speed of ■/'2n. The scanner home scanner 1 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 is opposed to it.

The filter selection mechanism section 28 includes a mirror 28ND that performs total reflection and three filter mirrors 28VB, 28MG, and 28CR that are radially provided at an angle of 90 degrees to each other around an axis 28a, and the axis 28a rotates. By positioning the fixed mirror 29, 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. ing. A mirror reference position sensor 25 is provided at the location where the selected mirror is positioned, and FIG. 1 shows the mirror 28ND selected and positioned.

Filter mirrors 28YB, 28MG, and 28CR are integrated mirrors and filters by depositing blue (B), green (G), 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 copying machine 1, and a paper ejection tray 33 that stores the paper P on which a copy image has been formed is provided 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 tie roller 20 in synchronization with the transfer belt 11, and after the toner image is secondarily transferred from the transfer belt 11, the paper P is conveyed. The image is sent to a fixing unit 19 by a belt 18 . A paper size sensor 13 is provided near the paper feed roller 21 to detect the size of the paper P, and a timing sensor 14 is provided near the timing roller 20 to detect the leading edge position of the paper P passing therethrough. ing.

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 photosensitive drum 2, transfer heald 11, paper feed roller 21,
Tying roller 20, conveyor belt 18, fixing roller 5
4, a paper ejection roller 53, and the like are rotationally driven.

In the color copying machine I configured as above, the above-mentioned Y
, M, C, and BK, and R (Y and M), G ( It is possible to form a base monocolor copy image of Y and C), B (M and C), and a color (2 color) copy image obtained by superimposing toner images of the three primary colors.

In forming single toner color and base monocolor 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 according to the designated color. The toner image is developed using any one of the containers 7 to 10, and the toner image is transferred onto the transfer belt 11. Furthermore, in the case of a composite monochrome copy image, the same original document is exposed and scanned again by the mirror 28ND, and any one of the developing devices 7 to 10 different from the one used before for composition is used. The developed toner image is transferred to a transfer heald 11, and the two color 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 the developing devices 7 to 9 are selectively switched to form and develop a latent image in which the document is color separated, and the toner images are sequentially transferred to the transfer belt 11, and the toner images of each color are formed on the transfer heald 11. It is formed by overlapping.

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 dove 1. Therefore, in the color copying machine 1 of this embodiment, the above-mentioned Rotational position signal S from the rotational position sensor 56
The timing at which the movement of the scanner 50 starts, that is, the timing at which the formation of a latent image on the photosensitive drum 2 starts is controlled based on the timing at which the IO occurs.

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

In the color copying machine 1, in order to simplify the optical system 40, as described above, the filter mirror 28VB is integrated with a mirror and a filter for color separation.

28MG and 28CR constitute a filter selection mechanism section 28, and a mirror that determines the optical path of the scanning light is movable.

For this reason, filter mirrors 28VB and 28MG.

Due to variations in accuracy or variations in the stop position (stop angle) when switching between the filters 28YB, 28MG, 28CR15 and the mirror 28ND, the mounting of the 28CR on the base requires the installation of 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 filters are 28YB,
Each exposure point θyθm of 28MG is shown.

When 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, resulting in color shift in the copied image. Image quality deteriorates.

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 coolers 28YB, 28MG, and 28CR are used as ND filter, B filter, G filter, and R filter, respectively, based on the 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, and a keypad 7 for displaying the number of copies.
Segment LED 201, clear/stop key 203
, an interrupt key 204, magnification up and magnification down keys 205, 206 for setting the copy magnification, a 3-digit 7-segment LED 207 for displaying the copy magnification, an amplifier and Keys and display LEDs used in normal copying operations, such as down keys 210 and 208, an LED 211 for displaying the density level of a copied image, an auto density setting key 209, and an auto density display LED 222, 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, 2238K, LBD 224a that displays whether the waste toner storage container is full, interrupt display LED 224b, paper P jam display LED 224c
, each color (Y,
Color key 225~ corresponding to M, CR, GB, BK)
231, Full color key 2 for specifying color copying
32, ○HP key 233, used when using a transparent sheet for OHP (overhead projector) as paper P, etc.
A book key 234 used when copying separately,
Display LEDs 235 to 244 corresponding to the keys 225 to 234 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 (central processing unit) 401 that controls the overall operation of the color copying machine 1, a scan morph control 452 that controls the drive of the scanner 50, and a lens that controls the movement of the main lens 26 according to the copying magnification. Motor control 453 and filter selection mechanism section 28
The main structure is a filter mirror mork control 454 that performs switching control.

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 20] 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 of the paper size sensor 13 and the timing sensor 14 and the rotational position signal SIO 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 Y, M, and C toner image can be changed in eight steps with respect to the generation timing of the rotational position signal S10.

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 menu 9 schematically showing the operation of the CPU 401. This is an inflow chart.

When the power is turned on and the program starts, first,
In step #J, 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, a manual process is performed to receive and receive signals from the operation keys on the operation panel OP, and in step #4, a display process is performed to display on the operation panel OP.

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.

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

Steps #11 to #18 are raw processing corresponding to the operation keys that specify the color of the copy image, and in each step, the monocolor mode of each single toner color of ¥, M, C, R , G, B monocolor mode, full color mode, and BK monocolor mode (corresponding to black and white copying).

In step #19, HP 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 raw processing in step #12 and step #13 in FIG.
Similar to the Y key processing, an on-check of the color key of the corresponding color and an empty check of the toner are performed, and if the check and nick conditions are satisfied, the M copy mode or the 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 the Y toner and the 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, R (red) and M (magenta) are visually similar colors, so even if it is impossible to color R due to a lack of Y toner, pressing the R key will not be ignored.
M copy mode is set as an alternative to R copy mode If both 6Y 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 G 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.

3 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.

In other words, G (green) and Y (yellow), and G and C
(cyan) is not considered a similar color to -g, 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 4M toner is performed in step #52. C toner and M
If both toners 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, stamp #
At step 64, a full color mode is set in which Y, M, and C toner images are superimposed.

If even one color of YMC toner is insufficient, it is impossible to form a color copy image, and the printer is returned without setting the full color mode.

FIG. 11 is a flowchart of the BK main key process of step #18 in FIG.

First, in step #70, a BK main key on check is performed, and if YES, an empty check of the BK main 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, if the answer is YES in step #71, an empty check is performed for each of the Y and MC toners in step GAF 2 to #74.

If all YM and C toners are present, step #7
5, Y formed sequentially using mirror 28ND,
A three-color overlay mode is set in which M and C toner images are overlaid.

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.

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 determined whether the OHP mode has already been set.

If YES in step #81, O 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 that makes the system speed of the entire electrophotographic process slower than the normal operation mode, which increases the time it takes the paper P to pass through the fixing unit 19 and prevents overlapping. The plurality of 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 sensor 7a~
Based on the signal from 10a, a toner empty process is executed to display the shortage of each toner on the operation panel OP, and in step #91, a color designation display process 8 is performed to display a color corresponding to the color designation of the copied image. Execute.

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, an empty check is performed for the M toner, and if YES, the LED 223M is turned on in step #104, and if NO in step #103, the LED 223M is turned off in step #105.

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, empty check the BK toner, and if YES, light up L E D 223 BK in step #11O, and proceed to step #1.
If no in 09, L E D in step #111
223 Turn off BK.

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

In this routine, first, in steps #120 to #I25, a check is sequentially performed 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 step #■20 to step #125, step #126 to step #13 are displayed to indicate that each copy mode has been set.
1 lights up the LEDs 235 to 240, 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. Step #
If 132 is YES, step #135 turns on LED2.
42 is lit.

If no in step #132, a check is made to see if BK copy mode is set in step #133, and if yes, LED 24 is set in step #136.
Turn on 1.

Also, if no in step #133, step #1
Check whether the 3-color overlay mode is set in step #134, and if yes, turn on the LED in step #137.
241 flashes.

If LBD241 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 mode again. In other words,
In the color copying machine 1, when black toner is insufficient, the operator selects whether to combine three primary color toners to form a blank copy image or to form a black copy image using black toner after replenishment. can do.

1. 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 count value of the state count is checked, and the following processing is executed depending on the state.

The state is "0" in the initial 1υj state immediately after the power is turned on and in the standby state after the copying operation is completed.

In state rQJ, first, in step #141, the print key 200 is checked, and if 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, a main motor start-up timer is set to wait for the rotation of the main motor 22 to stabilize, and in step #145, the state is set to "1".

In state "1", in step #1502, the main motor start-up timer is counted and amplified. As a result, each time step #50 is executed, the count number of the main motor start-up timer is updated and the time measurement progresses.

In the following step #151, a check is made as to whether or not the count number of the main motor start-up timer has reached a predetermined value, that is, the end of time measurement 6I El is performed, and if no, the process returns, and if YES in step #151, the process returns. ,
In step #152, the state is updated to "2".

In state "2", the paper feed roller 21 is turned on at step #16° 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 bar 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 #180, and the count-up is performed in step #180.
At step 181, the end of the paper loop timer is confirmed.

If the answer is yes to step #181, step-up.

Turn off the paper feed roller 21 in #182 and set the state to "5"
(Step #183).

In state "5", it is determined in step #290 whether or not it is the timing to register the paper P with respect to the toner image on the transfer bell 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 the mode is ○HP 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. Set it to "9".

If the answer in step #192 is NO, set a paper feed interval timer to keep the intervals between the sheets P constant in the transport path (step #193), and change the state to r6. (
Step #]94).

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, stay 1 is set to "7" in step #202.

In state "7", 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 ○P.

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 the completion of paper ejection is confirmed based on the 5 signal from the paper ejection sensor (not shown), the main motor 22 is turned off in step #221, and the state is set to "O".
Return to j (step #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 based on process timing whether a toner image of one color or a plurality of colors has been secondarily transferred from transfer belt II to 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 one fixing unit, the fixing roller 54
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 "10J".

6 In state "■0", 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 set to the normal speed. to return to.

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", in step #250, the process stability timer is counted and amplified, and in step #251, the completion of the process stability timer is confirmed.

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
02, the charger 5 and the main eraser lamp 4
4 of the electrophotographic process! ! Prepare.

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 times of secondary transfer from the transfer heald 11 to the paper P.

In state "21", it is checked in step #311 whether a mode for multiple transfer is set.

If no in step #311, that is, if a copy image is to be formed using toner of one color, step #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 heald 1q1, so the state is set to "26" in step #315.
Proceed to.

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 belt cleaner 15 is turned on to clean the transfer belt 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). Step #323L state is set to "23" to set an exposure lamp rise timer for waiting for the light amount to stabilize (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 state "24", scan completion TIi confirmation is performed in step #341, and if YES,
The exposure lamp 24 is turned off (step #342), and the previously turned on developing clutch is turned off (step #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 state "25", it is checked in step #351 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 #311 of state "21"
If it is determined that the mode is for multiple transfer, the processes in states "26" to "35" are executed.

In state "26", 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" indicating 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 to form a Y toner image first (step #366), and in the case of not the full color mode, that is, in the case of three-color overlapping mode, the ND filter is selected (step 436B). )
.

After executing step #366 or step #368, in step #367, set "3" to the scan counter.
Step 1 - Update.

For stay 1-r27J, in step #371,
It is checked whether the rotational position signal 310 has been generated, that is, whether the heald mark 57 of the transfer heald 11 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 SIO 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 SIO,
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 SIO 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 r28, the exposure lamp on timer is counted up in step #381, and step #381 is performed.
At step 382, the end of the exposure lamp on timer is confirmed.

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

In state "29", in step #391, it is checked whether the rotational position signal 310 is generated.

If YES in step #391, the exposure lamp on timer is set in step #392 and the scanner is started in step #393 in order to determine the lighting timing of the exposure lamp 24 in the second and subsequent color scans in the same way as described above. Outputs signal S230. Thereafter, the state δ is set to "30" (step #394).

In stay 1-r30J, first, step #40
In step 1, the completion of scanning is confirmed.

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

That is, turning off the exposure lamp 24 (step #402)
, turning off the developing clutch during driving (step #403),
Scan counter countdown (step #404
) is executed sequentially, the value of the scan counter becomes "0".
It is checked whether it is (step #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, the copy number counter is counted up.

Next, in step #407, it is checked whether the value of the copy number counter has reached 10, and if no,
The process moves to step #415 and advances the state to "34".

4 If YES in step #407, reset the copy number counter (step #408), turn on the heald cleaner 15 (step #409), and time the cleaning time (one rotation time of the transfer belt 11). Set the 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 multiple-transfer mode, i.e., pull color mode, composite color (R, G, B) copy mode, and 3-color overlapping mode, the same 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 copy count counter,
The electrophotographic process is interrupted every IO number of sheets P, and the transfer heald 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 full color mode 1', step #414
Then, advance the state to "31". 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 310 is generated by referring 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 every time the rotational position signal S10 is generated in relation to the book mode, it is checked whether the next scan is to scan the 8th side of the book.

The hook 8 surface refers to the scan direction (M
When the original document is divided into two sides using the center of 5) as a boundary, this is the side farthest from the home position of the scanner 50. Note that the closer side is the book A side, and in the book mode, the book A side and the book 8 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 S10 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.
Without outputting the
・Return to "28".

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 scans the paper P on the document table glass 31.
The reciprocating time of the scanner 50, which is determined by the mutual relationship between the size and feeding direction of the paper and the copying magnification set by the numeric keypad 202, etc., is determined in advance, and the number of occurrences of the rotational position signal 310 (" 1” or “
2) is stored as data.

In the notation of paper size in the same figure, for example, A3
Portrait 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. say.

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 each period of acceleration, constant speed, and deceleration is, for example, 3.0 seconds (
The forward movement is 2.2 seconds, the backward movement is 0°8 seconds), and in this case, the movement time is shorter than the generation period of the signal SlO, so
Scanning can be started continuously every time the signal SIO is generated (every rotation of the transfer heald).

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 it is not possible to start scanning ↓ consecutively every time signal SIO occurs. . Therefore, in this case, signal 310 is disabled on every other occurrence of signal 310, as described above, and scanning is initiated on every second occurrence of signal SIO.

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. S ],
The number of occurrences of 0 (“1” or “2”) is determined in advance.

Returning to FIG. 17, in state "33", the heald cleaning timer is counted up in step #441, and the completion 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 1 started at 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.

In Step) r35J, in step #461, it is checked whether the return of the scanner 50 has been completed.

If YES in step #461, the state is returned to "26" in step #462 in order to move on to the next copying operation.

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

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

In state "40", first, in step 1 #501, the presence or absence of the scanner start signal S20 is checked, and if YES, the process advances to step #502.

In step #502, the optical system 40 checks the filter selected according to the color of the toner, and the 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,
At 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 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 above-described embodiment, 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. Since this is prohibited, it is possible to always form high-quality copied images under stable process conditions.

In the embodiment described above, the color copying machine 1 uses an intermediate transfer method in which a transfer belt 11 as an intermediate transfer medium is provided between the photosensitive drum 2 and the paper P, and toner images of each color are superimposed on the transfer belt 11. However, as a method of superimposing toner images, there is a method of superimposing toner images on copying paper wrapped around a rotating body such as a transfer drum, or a method of superimposing on a photoreceptor drum (for example, Japanese Patent Application Laid-Open No. 61-32854 ) The present invention can also be applied to color copying machines that employ the following.

[Effects of the Invention] 5. According to the present invention, the rotating body for overlapping toner images can be made smaller while maintaining the accuracy of toner image alignment;
It is possible to increase the number of copies 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), 50...
Scanner, 56... Rotational position sensor (rotational position detection means), 401... CPU (scanning control means), S1
0... Rotational position signal.

Claims (1)

[Claims] (1) A scanner that moves back and forth to scan a document, and a plurality of developing means that each develops a latent image formed by scanning the document using toner of a different color to form a toner image. , a rotating body that rotates in response to scanning in order to superimpose each of the toner images, a rotational position detection means that generates a rotational position signal every rotation of the rotational body, and a rotational position detection means that generates a rotational position signal based on the rotational position signal. scanning control means for starting the forward movement of the document, by scanning the same original document multiple times, sequentially forming toner images of each color for each scan, and superimposing the toner images on the rotating body. In a color copying machine that forms a color copy image, when scanning the same document multiple times, the rotational position signal is transmitted a predetermined number of times according to the reciprocating time of the scanner in one scan. 1. A color copying machine characterized in that scanning is started every time .