JPH03186871A - Color copying machine - Google Patents

Abstract

PURPOSE:To increase the number of copied sheets per unit time while the fixed quality of a color copied image is secured by cleaning the surface of a rotor for transfer every time when at least two or more prescribed sheets of the color copied image are formed in forming the plural sheets of the color copied image of one original. CONSTITUTION:Toner images of plural colors are superposed on the rotor for transfer 11 and the color copied image corresponding to the original D is formed. Then, in the case that the plural sheets of the color copied image are formed with respect to one original D, the surface of the rotor 11 is cleaned every time when at least two or more prescribed sheets of the color copied image are formed. Thus, the number of the copied sheets per unit time is increased while the fixed quality of the color copied image is secured.

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 corresponding to a document by superimposing toner images of a plurality of colors.

[Conventional technology]

A typical color copying machine is equipped with a transfer rotating body such as a transfer drum and a transfer heald, and uses the transfer rotating body to transfer a toner image formed on a photoreceptor to copy paper in response to scanning of a document. is configured to do so.

The method of transferring toner images onto copy paper in the formation of color copy images is to perform color separation of the original, sequentially form three-color 1-toner images, and then wrap the toner images on the copy paper wrapped around the circumferential surface of a rotating body for transfer. A method of transferring each toner image onto copy paper, and a method of primary transferring three-color toner images from a photoreceptor to a transfer rotating body in the order of formation, and then superimposing the three-color toner images on the transfer rotating body. There is a method of secondarily transferring images to copy paper all at once.

In conventional color copying images, a cleaning device is installed to clean the transfer rotary body to prevent deterioration of the image quality of the color copy image due to excess toner or stains on the back side of the copy paper, and to prevent the formation of a single copy image. The transfer rotary body is cleaned every time the transfer is performed.

Cleaning is performed by idly rotating the transfer rotary body while contacting the scraping roller or brush of the cleaning device.

There are color copying machines that are specially configured to perform cleaning for a longer time than normal in the event of a copy paper jam or a large amount of toner adhering to the transfer rotor. Japanese Patent Publication No. 59-31990
Publication No.).

[Problem to be solved by the invention]

In conventional color copying machines, apart from special cases such as when a jam occurs, during the normal operation of forming a color copy image, a waiting time is required for cleaning each time a color copy image is formed. .

For this reason, especially when performing so-called continuous copying (multi-copying) in which multiple copies of the same original are made, the number of copies per unit time, that is, the number of copies that can be made within a certain amount of time. There was a problem in that the value of the index indicating .

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a color copying machine that can increase the number of copies per unit time while ensuring a constant quality of color copy images.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a color copying machine that forms a color copy image corresponding to an original by superimposing toner images of multiple colors on a transfer rotary body. On the other hand, when a plurality of color copy images are formatted, the surface of the transfer rotary body is cleaned every time a predetermined number of at least two or more color copy images are formatted. It consists of

[For production]

The toner images of multiple colors are superimposed on the transfer rotary body to form a color copy image corresponding to the original.

When formatting a plurality of color copies of one document, the surface of the transfer rotor is cleaned every time a predetermined number of at least two color copies are formatted.

〔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.
are arranged so as to be rotatable in the clockwise direction, and around the photoreceptor drum 2 are a cleaner unit 3, a main eraser lamp 4, a charger 5, and an LE as a partial eraser.
A D array 6, developing units 7 to 10, and a transfer belt 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 then charged by an optical system 4o, which will be described later, to form a latent image. exposed to light.

Each developer 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 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 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. There is. Rotational position sensor 5
A photo sensor 6 generates a rotational position signal 310 when it senses reflected light from a belt mark 57 provided at one location on the inner surface of the transfer belt 11.

Further, around the outside of the transfer heald 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 belt 11 are provided. The belt cleaner 15 can be selectively brought 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 roller 29, etc., and when the scanner 50 moves forward, it scans the document tray 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 V, v
The second slider 52 is driven by the scan morph 70 to move forward at a speed of /n (n is the copying magnification), and the second slider 52 is moved forward at a speed of /2n. Scanner home switch 7
Reference numeral 1 is a photo sensor that 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 is centered around a shaft 28a.
A mirror 28ND that performs total reflection and three filter mirrors 28YB, 28MG, and 28CR are provided radially at an angle of 90 degrees to each other, and by rotating and positioning the shaft 28a, any of these mirrors The scanning light is guided to the exposure point of the photoreceptor drum 2 via the fixed roller 29 by the selected mirror. A 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 28Y8, 28MG, and 28CR are made by integrating a mirror and a filter by vapor-depositing blue (B), green (G), and red (R) color separation filters on the mirror surface, respectively. It is used for M and C color toners.

On the other hand, color copy I! A paper cassette 32 that stores paper P is attached to the lower left side of 11, and a paper ejection tray 3 that accommodates the paper P on which a copy image has been formed is installed at the lower right side.
3 is provided.

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 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. I'm being held back.

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 belt 11, paper feed roller 21,
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 ( A composite monochrome copy image of Y and C), B (M and C), and 3
It is possible to form a color (full color) copy image obtained by superimposing toner images of 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 monochrome copy image at the bottom, exposure scanning is performed again on the same original by the mirror 28ND, and any one of the developing devices 7 to 10 for the bottom is used. The developed toner image is transferred to a transfer belt 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 color-separated from the original, and the toner images are sequentially transferred to the transfer heald 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 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 at which the movement of the scanner 50 starts, that is, the timing at which latent image formation 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, the filter selection mechanism section 28 is configured by the filter mirrors 28Y828MG and 28CR, which are integrated with a mirror and a filter for color separation, as described above. The bracket that determines the light path is movable.

For this reason, filter mirrors 28YB, 28MC,.

Due to variations in accuracy or variations in the stop position (stop angle) when switching the filters 28YB, 28MG, 28CR1 and mirror 28ND, the mounting of the 28CR on the base requires mounting the photoreceptor drum using the four ξGs 28Y8, 28. There may be a shift in the exposure point on 2.

In the figure, filter mirrors 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 310 is made 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 O is set for each color 28YB.
28MG, 28CR. It is said that it can be adjusted every 28ND.

In the following explanation, the filter mirrors 28ND, filter mirrors 28YB, 28MG, and 28CR are used as ND filters, B filters, G filters, and R filters, 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 ○P, 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 L E D 2 0 7 to display the copy magnification
, up and down keys 210, 208 for manually setting the density of the copied image step by step, LED 211 for displaying the density level of the copied image, auto density setting key 2
09, keys and display LEDs used in normal copying operations, such as 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, LED 224a that indicates whether the waste toner storage container is full, interrupt display LED 224b, paper P jam display LED 224
c. Each color (Y
, M, C, R, CB, BK)
5 to 231, full color key 232 for specifying color copying, OH used when paper P is a transparent sheet for OHP (overhead projector), etc.
P key 233, book key 23 used when copying the left and right pages of a spread of a book etc. on two sheets of paper P
4, and display LEDs 235 to 244 corresponding to the keys 225 to 234, respectively, 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 CPIJ (central processing unit) 401 that controls the entire operation of the color copying machine 1, and a scanner 50.
a scan motor control 452 that controls the drive of
A lens motor control 453 that controls the movement of the main lens 26 according to the copying magnification, and a filter selection mechanism section 2
The bottom of the tank is centered around a filter mirror motor 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 201 and 5 display LEDs related to operation mode and color designation are connected through the switch matrix 450 and decoder 451, and their lighting or extinguishing is controlled.

Further, the output signals of the above-mentioned paper size sensor I3 and timing sensor 14 and the rotational position signal SlO are input to the input terminal of the CPU 401, and based on the signals from each of these sensors and the switch matrix 450, the output terminal is The connected 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 series of depth inches 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 and MC toner image can be changed in eight steps relative to the generation timing of the rotational position signal SIO.

As a result, in the color copying machine 1, the exposure points 6 corresponding to the B filter, G filter, and R filter can be corrected to match the exposure points of the reference ND filter, resulting in high image quality without color shift. 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 ink faces 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 on the operation panel OP, and in step #4,
Executes display processing for displaying on the operation panel OP.

Next, paper feeding/feeding processing (step #5) that controls the feeding and conveyance of paper P, image creation processing related to the electrophotographic process (step #6), and scanning for scanning original D. A series of copy sequence processes consisting of processing (step #7) are 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 there is Y toner, in step #28, Y l-
Sets the Y copy mode in which monochrome copying is performed using only the color printer.

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.

9. First, in step #30, check the R key, and if YES, perform an empty check of the Y toner 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, 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 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, perform an on-check of the G key, and if YES, perform an empty check of the Y toner 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 G 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 generally not considered a similar color, 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, B (red) and C are visually similar colors, so even if it is impossible to color B due to lack of M toner, do not ignore pressing the B key (B copy C copy mode is set as an alternative to the mode.

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 #6I 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 flat key process in step #18 of FIG.

First, in step #70, a BK main key on check is performed, and if YES, a BK main key empty check is performed in step #71.

If there is BK toner, in step #76,
Set the BK copy mode to perform monochrome copying 3 using only BK toner.

On the other hand, if the answer is YES in step #71, the empty check for each of the Y and MC toners is sequentially executed in steps Gaff 2 to Step #74.

If all Y, M, and C toners are present, step #
75, Y formed sequentially using mirror 28ND
, M, and C toner images are set.

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 checked whether the OHP4 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 HP mode is set.

Here, the ○HP mode is an operation mode in which the system speed of the entire electrophotographic process is made slower than in the normal operation mode, and as a result, the time for the paper P to pass through the fixing unit 19 is increased, and the paper P is overlapped. 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, toner empty processing is executed to display the shortage of each toner on the operation panel OP, and in step #91, color specification display processing is executed to display the copy image according to the specified color. do.

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 off in step #102.

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

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 on in step #108. Turn off the light.

Finally, in step #109, an empty check is performed on the BK toner, and if YES, the LED 2238K is turned on in step #110, and if NO in step #109, the LED 2238K is turned on in step #I11.
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 #125, a check is sequentially executed to see if a copy mode corresponding to each monochrome color of Y, M, C, R, G, and B is set.

If YES in each of steps #120 to #125, steps #126 to #125 are displayed to indicate that each copy mode has been set.
In step #131, 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 to check whether the full color mode is set.

perform the process. If YES in step #132, the LED 242 is turned on in step #135.

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 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 this is not the case, replenish the black toner and then specify the BK mode again. In other words, when a color copying machine runs out of black toner, it either uses toner of the three primary colors to form a blank copy image, or uses blank toner after replenishment to form a black copy image. The operator can select either.

FIG. 15 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 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 stay] is "0".

In state "0", 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 for waiting for the rotation of the main motor 22 to become stable is set to ``1'', 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 "2", 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 stay 1-r3J, the tying sensor 14 is turned on in step #170.

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

In state "4", the paper loop timer is amplified one time in step #180, and the completion of the paper loop timer is confirmed in step #181.

If YES in step #181, step #18
2, the paper feed roller 21 is turned off and the state is set to "5" (step 4183).

In state "5", in step #90, it is determined whether or not it is the timing to register the paper P with respect to the toner image on the transfer belt 11.

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

In the following step #192, it is checked whether the mode is ○HP 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. Set it to "9".

If no in step #192, set a paper feed interval timer to keep the intervals between sheets P constant in the conveyance path (step #193), and set the status to "6" (step #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 "7", in step #210, it is checked whether multi-copy with the number of copies of 2 or more is specified by the operation panel OP.
* is returned to "2", and in the case of a 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 a signal from a paper ejection sensor (not shown), the main motor 22 is turned off in step #221, and the stay 1 is returned to "0" (step #222).

If the HP mode is determined in step #192 of state "5" described above, the processes of state "9" to state rl IJ are executed.

In state "9", first, in step #230, it is checked at the timing of the process whether the toner image of one color or a plurality of colors has been secondarily transferred from the transfer head 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.

Thereafter, in step #232, the state is set to "IO".

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 rotation speed of the main motor 22 is set to the normal speed. Return.

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
Then change the state back to 7J and return 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 r20j, first, print key 20
Perform 0 onchi-5tsuk (Step #301).

If step #301 is YES, follow step #3
02, charger 5 and main eraser lamp 4
etc., and 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 times of secondary transfer from the transfer heald 11 to the paper P.

5. 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 belt 11, so the state is advanced to "26" in step #315.

In step #3I2, the filter selection mechanism unit 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 belt 11, and the state is advanced to "22" (step #314).

In state "22", the exposure lamp 24 is turned on, and in step #321L, one of the five developing clutches of the developing units 7 to 10 is turned on according to the set copy mode (step #322), the exposure lamp 24 is turned on. Set the exposure lamp start-up timer to wait for the light amount to stabilize (step #323), and set the stay 1 to "23" (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 "24j" in step #334.

In state "24", the end of scanning is confirmed 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 r21J
If it is determined that the mode is for multiple transfer, the processes from state "26" to state 135J are executed.

In state 26J, the number of colors that are at the bottom 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, first select the B filter to form a Y toner image (step #366); if not in full color mode, that is, in the case of three-color superimposition mode, select the ND filter (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 state "27", it is checked in step #371 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 belt 11 is rotationally driven 9 at a constant speed, and the period of generation of the rotational position signal SIO is constant. Therefore, in the color copying machine 1, the amount of light from the exposure lamp 24 is stabilized during scanning that is started based on the generation timing of the rotational position signal 310.
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.

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

In state 128, 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 "29" (step #385).

In state "29", in step #3901, it is checked whether the rotational position signal SIO is generated.

If YES in step #391, the exposure lamp on timer is set in step #392 in order to determine the lighting time of the exposure lamp 24 in the second and subsequent color scans in the same way as described above, and in step #393, the exposure lamp on timer is set. , outputs a scanner start signal S20. After that, the state is set to "30" (step #394).

In state "30", first, step #401
to confirm the completion of scanning.

If the scan is completed, the subsequent steps #402 to #4I5 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 #4
04) in sequence, the value of the scan counter becomes “
0” (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,
Proceed to step #415 and set the status to ``Proceed to 34J.''

If YES in step #407, the number of copies counter is reset (step #408), the heald cleaner 15 is turned on (step #409), and the cleaning time (one rotation time of the transfer belt 11) is measured. Setting the belt 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 plate 11 after the secondary transfer, the effect on the next sheet P is small.
Although it is not necessary to clean the transfer heald 11 for each sheet of paper P, there is a risk that the image quality of the copied image will deteriorate if residual toner accumulates. Therefore, in color copying machines, 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 heald 11 is cleaned.

On the other hand, if "No" in the double step #405,
The process advances 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 the 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 "31j," in step #4231, it is checked whether scanning is possible every time the rotational position signal 310 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 S10 is generated in relation to 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 Fook A side, and in the Fook mode, the Fink A side and the 1798 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 22, the state is advanced to 32j in step #424.

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

If YES in step #431, step #43
After the exposure lamp on timer is set in step 2, the scan start signal S20 is not output unlike the two consecutive states 29, and the state is returned to 28 in the subsequent step #433.

That is, in this case, the rotational position signal 310 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 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 sio, which is a necessary condition for starting scanning ( l” 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 peripheral length of the transfer heald 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 bell (11) (the period of generation of the rotational position signal 310) 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 (
Forward movement is 2.2 seconds, backward movement is 0°8 seconds), and in this case, the movement time is shorter than the generation period of signal S10, so
Scanning can be started continuously each time the signal 310 is generated (every rotation of the transfer belt).

On the other hand, in the case of A314 paper P, even if it is a same size copy, the reciprocating time of the scanner 50 is as follows.
5.4 seconds (4.2 seconds for forward movement, 1.2 seconds for backward movement) and signal S1. Since it is longer than the generation period of O, the signal SI
It is not possible to start scanning continuously every time O occurs. Therefore, in this case, the signal 3
10 is disabled on every other occurrence of the signal SIO, and a scan is initiated on every second occurrence of the 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. The number of occurrences of SIO ("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 #4412.

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

After that, in step #444, the state is updated to "34J."

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 state "35", it is checked in step #461 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, 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 #50G, and in each step, the state is updated after setting the G delay timer and the R delay timer whose measurement times are set by dip switches 456 to 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 return of the scanner 50 is started in step #522, and the stay 1 is advanced to "43j" (step #523).

In ST) r4LJ, wait for the scanner 50 to return to the home position, confirm the return stepchild in step #524, and return the state to the initial value 140'' in step #525.

According to the above-described embodiment, when switching from the ○HP mode for increasing the translucency of the copied image to the normal copying mode, the electrophotographic process is executed 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. As shown in Example 1, as a method of superimposing toner images, there are two methods:
Alternatively, a method performed on a photoreceptor drum (for example,
The present invention can also be applied to a color copying machine that employs the color copying machine (Japanese Patent Publication No. 1-32854).

〔Effect of the invention〕

According to the present invention, it is possible to increase the number of copies per unit time while ensuring a constant quality of color copy images.

[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. L...Color copying machine, 11...Transfer heald (rotating body for transfer), D...Document. 2 Fig. 4 JP-A No. 3-186871 (17) Fig. 1 Fig. JP-A No. 3-186871 (19) Fig. 6=;0 Fig. 1 Fig. #104 Fig. JP-A No. 3-186871 (21) 3 186871 (28)

Claims (1)

[Claims] (1) In a color copying machine that forms a color copy image corresponding to an original document by superimposing toner images of multiple colors on a transfer rotary body, a color copy image of multiple sheets of color copy images is created for one original document. In the color copying machine, the surface of the transfer rotating body is cleaned every time a predetermined number of at least two color copies are formed.