JPH0685098B2 - Electrostatic transfer type color recording device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an electrostatic transfer recording device, and more particularly to improving image quality.

[Prior Art] In an electrostatic transfer type recording apparatus, for example, an electrostatic copying machine, a series of processes such as charging, exposure, development and fixing are performed,
A copy of the original image is recorded on a predetermined recording paper. In this type of recording apparatus, it is preferable to reproduce an image that is as faithful to the original image as possible. Therefore, regarding the gradation, it is sufficient that the density (or density) of the original image and the density of the recorded image are in a proportional relationship.

However, in a normal copying machine, it is not possible to use the same as shown in Figures 6a and 6b.
As shown in the figure and FIG. 6c, the relationship between the document density and the copy density is not linear. In particular, the copy density is saturated in an area where the original density is high. Gradation cannot be reproduced in a region where the copy density is saturated. Further, in a color copying machine, when the density is saturated, the color balance is lost and a difference occurs between the color of the original image and the color of the recorded image. The relationship between the original density and the copy density is shown in Fig. 6a (characteristics with adjusted developing bias voltage), 6b.
As shown in FIG. 6 (characteristics in which the exposure amount is adjusted) and FIG. 6c (characteristics in which the charging voltage of the photoconductor is adjusted), various forms can be changed by adjusting various parameters relating to the recording process. However, as can be seen from these drawings, no matter what adjustment is made, it is not possible to make the relationship between the original density and the copy density linear over a wide density range.

For this reason, conventionally, in a copying machine, many parameter adjusting means are provided to adjust various parameters so that the most preferable image can be obtained according to the type of the original image. Therefore, in order to obtain a desirable copy, many test copies must be taken, and even with strict adjustments, sufficient image quality can be obtained for documents with a wide range of gradation changes such as photographs. I can't.

For example, by adjusting the exposure amount, the characteristic of original density-copy density can be shifted with respect to the value of original density, as shown in FIG. 6b. Therefore, the characteristics A and B of FIG. 6d can be realized respectively. When characteristics A and B are combined (characteristic of A + B), characteristics close to ideal characteristics are obtained over a wide concentration range.

In order to achieve this, the parameters are adjusted and the characteristic A
The copier is set to the state of No. 1, the first image formation and transfer are performed, the parameters are readjusted, and the state of the characteristic B is set,
The second image formation and transfer may be performed. This allows
A high-quality image is recorded on the recording sheet according to the characteristics of A + B. When performing color recording, Y
The first and second image formation and transfer may be performed for each of the developed colors of (yellow), C (cyan), and M (magenta).

[Object of the Invention] By the way, in a recording apparatus that forms a color image by using developers of a plurality of colors such as yellow (Y), magenta (M), and cyan (C), the color of the recorded image is the original image. It is very important to adjust the color balance among Y, M, and C in order to approach the color of. That is, even if the recording density of each color of Y, M and C is almost proper, the ratio of Y / M of recording density, M / C
If the ratio of C and the ratio of C / Y are not appropriate, a large color gap occurs between the original image and the recorded image, and the recording quality of the color image is low.

Therefore, an object of the present invention is to facilitate adjustment of color balance of an electrostatic transfer type color recording device.

[Configuration of the Invention] In order to achieve the above object, in the present invention, a charge carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the charge carrier; A developing unit that has a plurality of color developers and visualizes the electrostatic latent image with the plurality of color developers; a transfer unit that transfers the image visualized by the developing unit to a predetermined recording sheet; And a recording process of forming an electrostatic latent image on the charge carrier, visualizing the electrostatic latent image, and transferring the visible image to a recording sheet is set for each color of the plurality of color developers. In the electrostatic transfer type color recording apparatus, which includes a process control unit that executes according to the parameters, a plurality of parameter storage units (MAn, MBn) that hold the values of the parameters for each color of the developers of the plurality of colors. , MC
Of n, MDn, one set of memory corresponding to one set of Y, M, C); Temporary storage means (one set of memory corresponding to one set of Y, M, C of MIn); Input operation In response to, the values stored in the plurality of parameter storage means are transferred to the temporary storage means by using the plurality of colors as one unit, and memory transfer means (KMA, KMB, KMC, or KM).
D); a plurality of sets of increase / decrease instruction means (KG1, KG2, or KG3) provided in association with the respective colors of the plurality of colors of developer; Of the set of increase / decrease instructing means, the increase / decrease processing means (processing of FIG. 9a) for increasing / decreasing the value held in the temporary storage means for the color associated with the input / output increase / decrease instructing means; In response, the registration instruction means (K6); which transfers the value held in the temporary storage means to the parameter storage means in units of the plurality of colors is provided.

Here, the description in parentheses indicates the corresponding elements in the examples described later.

[Operation] In the present invention, recording of a color image is carried out by using developers of a plurality of colors such as Y, M, and C. The values of the parameters used in the recording process (for example, original image reading sensitivity, charge voltage of the charge carrier, developing bias voltage, etc.) are determined by the parameter storage means (MAn, MBn, MCn, MDn) among Y, M, A set of memories corresponding to a set of C) is held for each color of the plurality of color developers, and in order to adjust parameters for each color of the plurality of color developers. , A plurality of sets of increase / decrease instruction means (six keys of KG1, six keys of KG2, or six keys of KG3) are provided.

When the operator operates the memory transfer means (KMA, KMB, KMC, or KMD), in response to the input operation, the values held by the plurality of parameter recording means are changed to the plurality of colors (Y, M, C). ) As one unit, and they are transferred to the temporary storage means (one set of memories corresponding to one set of Y, M, and C in MIn).

Thereafter, when the operator operates the increase / decrease instruction means, the increase / decrease processing means (processing in FIG. 9a) causes only the color associated with the input / output increase / decrease instruction means to be changed,
The value (parameter of the Y, M or C color recording process) held by the temporary recording means changes. Further, when the registration instructing means is operated, the value held in the temporary recording means is transferred to the parameter storage means with the plurality of colors (one set of parameters of all of Y, M and C colors) as one unit.

That is, when the operator tries to set the parameters, the values of the parameters (Y, M, and C colors) that have been set up to that point are read at once from one set of parameter storage means and stored in the temporary storage means. After being transferred, it is updated and re-registered in the parameter storage means. Therefore, the value of the parameter after the adjustment is set based on the value of the parameter actually used before the adjustment, so that even if the operator does not remember the value before the adjustment, for example, one step more than before. The operation of adjusting the density in the darkening direction can be easily performed. This makes it possible to easily make fine adjustments to the image quality.

Especially, the adjustment of the parameter increase
Since each of C) can be carried out independently, the adjustment can correct not only the density but also the color balance.

For example, as a result of the operator comparing the original of the copy image output as the test print, if the Y color of the copy image is desired to be dark, the memory transfer means (KMA, KMB, KMC,
Or KMD) to transfer a set of Y, M, and C parameters at that time to the temporary storage means, and then operate the Y-color increase / decrease support means to increase the Y-color density. The color and C color increase / decrease instructing means are respectively operated to reduce the density of the C color of M color, and the registration instructing means is operated to operate (Y, M,
C) If a copy image is recorded again after updating and registering one set of parameters in the parameter storage means, a copy image in which the Y color is emphasized more than in the previous test printing is obtained.

Further, for example, when it is desired to emphasize blue, which is a composite color of C color and M color, memory transfer means (KMA, KMB, KMC,
Or KMD) to transfer a set of Y, M, and C parameters at that time to the temporary storage means, and then operate the C color and M color increase / decrease instruction means, respectively, to change the density of C color and M color. To increase
Operate the registration instruction means to (Y, M, C) 1 on the temporary storage means
The copy image may be recorded after the parameters of the set are updated and registered in the parameter recording means.

Therefore, according to the present invention, the color balance adjustment operation is very simple.

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

FIG. 2 shows a mechanical section of one type of color copying machine embodying the present invention. This will be described with reference to FIG. Reference numeral 40 is a contact glass on which a document is placed. Contact glass 40
Underneath, there is an optical operating system. The optical scanning system is equipped with an exposure lamp 3, a first mirror 4, a second mirror 5, a third mirror 6, a lens 7, a fourth mirror 8, a color separation filter 9, and the like. The light emitted from the exposure lamp 3 strikes a document (not shown) on the contact glass 40, and the reflected light reflects the first mirror 4, the second mirror 5, the third mirror 6, the lens 7, the fourth mirror 8, and the like. The light enters the surface of the photoconductor drum 1 through the color separation filter 9.

The color separation filter 9 is provided with three filter plates of R (red), G (green) and B (blue) arranged at an angle of 120 degrees to each other. Is inserted in the optical path of the optical scanning system. By driving a filter motor M5, which will be described later, the color separation filter 9 is rotated and the selection of the filter plate is changed. By inserting the R, G, and B filter plates in the optical path in sequence and performing document reading scanning, a document image separated into the R, G, and B basic colors (three primary colors of light) can be obtained. In this example, the filter plates are selected in the order B, R, G. In order to know the position of the filter plate, there is a home position sensor (SE5 described later) that detects whether or not the blue filter plate is inserted in the optical path.

In the vicinity of the peripheral surface of the photosensitive drum 1, a charger (main charger) 10, an eraser 11, a magenta (M) developing roller 12, a cyan (C) developing roller 13, a yellow (Y) developing roller 14, a transfer drum 2, A transfer charger 18, a pre-cleaning static eliminator 19, a cleaning unit 20, a static eliminator 21 and the like are provided.

In FIG. 2, the photosensitive drum 1 rotates counterclockwise and the transfer drum 2 rotates clockwise. The transfer charger 18 is arranged inside the transfer drum 2 at a position close to the photosensitive drum 1. The cylindrical portion of the transfer drum 2 that holds the recording sheet is made of a dielectric film and comes into contact with the surface of the photosensitive drum 1 via the recording sheet when performing a recording operation. Two separation chargers 22 and 23 are arranged at a position downstream of the transfer charger 18 of the transfer drum 2 so as to sandwich the peripheral wall of the transfer drum 2.

The paper feed system is equipped with two paper feed cassettes 26 and 27,
Either one is selected. The lower paper feed unit is equipped with a calling roller 28, a paper feeding roller 29 and an inverse point roller 30,
By driving these, recording sheets are fed one by one from the paper feed cassette 26. The same applies to the upper sheet feeding section.

Recording sheets fed from the upper or lower tray
41 is stopped at the position of the registration roller 31 and is fed to the transfer drum 2 in synchronization with the rotation timing of the transfer drum 2 as shown in FIG. 3b.

On the outer peripheral surface of the transfer drum 2, one clamp plate 2a is provided in parallel with the rotation axis thereof. The clamp plate 2a is normally closed, but it is opened and closed by the cam mechanism 2b by driving a motor M7 described later. That is, when feeding the recording sheet 41, the clamp plate 2a is opened, and the recording sheet 41 is
When the sheet enters between the clamp plate 2a and the transfer drum 2, the clamp plate 2a is closed to clamp (hold) the leading edge of the recording sheet 41.
To do. Since the transfer drum 2 is charged by passing the transfer current, an electrostatic attraction force acts, and thereby the portion other than the leading end of the recording sheet 41 is also held on the transfer drum.

When all the images have been transferred, the separation chargers 22 and 23
Static electricity is removed by applying a predetermined AC voltage to
At the same time, the clamp plate 2a is opened and the recording sheet 41
Is separated from the transfer drum 2.

As shown in FIG. 3a, the photosensitive drum 1 and the transfer drum 2
Are connected to each other by gears 45 and 46,
45 is coupled to the main motor M1 via the transmission mechanism 42. The transmission mechanism 42 includes a home position sensor HP1.

Referring again to FIG. The recording sheet is a transfer charger.
The sheet is separated from the transfer drum 2 through 22 and 23, is thermally fixed through a fixing roller 32 and a pressure roller 33 in a fixing unit located downstream of the transfer drum 2, and is then discharged.

The operation board OP1 of the color copying machine shown in FIG. 2 is shown in FIG. 4a. Referring to FIG. 4a, this operation board has an indicator
DP1, numeric keypad KT, magnification key K1, paper key K2, clear / stop key K3, interrupt key K4, print key K5, density adjustment knob A
J, mode selection keys KMA, KMB, KMC, KMD and mode display DP2
Is equipped with.

In this example, by operating the mode selection keys KMA, KMB, KMC and KMD, the copying process can be executed with five kinds of preset density characteristics. Immediately after turning on the power of the device, the normal mode (or the first mode) is selected, and by pressing the mode selection keys KMA, KMB, KMC and KMD, the A mode (the second mode) and the B mode (the third mode) are selected. Mode), C mode (fourth mode) and D mode (fifth mode).

In order to set the characteristics of each mode, this color copying machine is equipped with a color balance setting board OP2 shown in FIG. 4b. The setting board OP2 is located near the operation board OP1, but is normally covered with a cover (not shown).

Referring to FIG. 4b, this color balance setting board OP
The 2 has a large number of keys and a display DP3. The six keys KG1 are for adjusting (UP, DOWN) the developing bias voltage for each of Y, C, M, and the six keys KG2 are for changing the applied voltage of the main charger 10 to Y, C, M. The six keys KG3 are for adjusting the light amount level of the exposure lamp 3 for each of Y, C, and M. The key K6 is a memory-in key for storing the value updated by the keys KG1, KG2, and KG3 in the memory in the designated mode. Key K7 is a key for selecting the full color mode and the single color mode.

The display part DP3 is equipped with nine 7-segment numerical indicators, and nine parameters, namely, Y, C, M, and
Main charger voltage Y, C, M, exposure level Y, C, and M
One display digit is assigned to each of the. Since 0,1,2,3,4,5,6,7,8,9, A, B, C, D, E and F can be displayed in each display digit, there are 16 levels for each of 9 parameters. Can be displayed. In other words, this color balance setting board OP2 can adjust the level in 16 steps for each parameter.

FIGS. 5a, 5b, 5c, 5d, and 5e show the outline of the electric circuit configuration of the color copying machine shown in FIG. Refer to each figure. A main control board 100 controls the entire device. Sensors, motors, solenoids, etc. are connected to the main control board 100 via various units.

First, referring to FIG. 5a, the paper feeding unit 110 is connected to the main control plate 100. The paper feed unit 110 includes a sensor group including a registration detection sensor 111, paper end sensors 113 and 118, limit position sensors 114 and 119, paper size sensors 115 and 120, a feed roller stop solenoid SOL3, call roller control solenoids SOL4 and SOL5, and a registration motor M2. A sheet feeding motor M3 and a sheet feeding table motor (for pressurization) M4 are connected.

Referring to FIG. 5b, the main control plate 100 is connected to the development control plate 1
20 connected. To the development control plate 120, Y, C, and M development units 122, 123, and 124 and various clutches are connected. The development control plate 120 has a microcomputer 1 inside.
It is equipped with 21, and automatically adjusts the toner density in each developing unit. The current output lines B-S and B-D from the high-voltage power supply unit 130 shown in FIG. 5c are connected to the developing roller and the scooping roller of each developing unit.

Referring to FIG. 5c, the high voltage power supply units 130, 140, 150 and the eraser 11 are connected to the main control board 100.
The high-voltage power supply unit 130, based on the 6-bit charging control signal, the 4-bit transfer control signal, and the 5-bit developing bias control signal from the main control board 100, the charging voltage output line C, the transfer current output line T, and Predetermined electric power is supplied to the developing bias voltage output lines BD and BS, respectively.
The charging voltage output line C of the voltage power supply unit 130 is connected to the main charger 10, and the transfer current output line T is connected to the transfer charger 18.

The high voltage power supply unit 140, when the charge removal charger on signal from the main control board 100 is turned on, the charge removal charger 19 and
Apply a predetermined static elimination voltage to 21. High-voltage power supply unit 150
Applies a predetermined amount of voltage between the separation chargers 22 and 23 when the separation charger ON signal from the main control board 100 is turned on. In this example, the separation charger on signal is 2
It has become a bit, and the separation voltage can be switched between AC 5.5KV and AC 4KV. When a voltage of 4 KV is applied, the charge is not sufficiently removed, so the recording sheet does not peel off from the transfer drum.

Referring to FIG. 5d, an AC power supply unit 160 is connected to the main control board 100. The AC power supply unit 160 performs voltage conversion, AC power switching, and the like. A lamp regulator, a developing motor, a main motor M1, a fixing heater, a fixing fan, a fixing drive motor, a power transformer, etc. are connected to the AC power supply unit 160. Inside the AC power supply unit 160, a filter, a relay, and many solid state relays are provided.

Referring to FIG. 5e, the control board O
P1, color balance setting board OP2, memory unit 170,
The fixing unit 180, the lamp regulator 190, and the motor control unit 200 are connected. In this example, the dimming level of the lamp regulator 190 is set by a 5-bit control signal from the main control board 100.

The motor control unit 200 includes a filter motor M5, a lens motor M6, a clamp motor M7, a return motor M8, a cleaning motor M9, and sensors SE5, SE6, SE7, SE8 for detecting the home position of a mechanism driven by each motor. And S
E9 is connected. The filter motor M5 drives the color separation filter 9, the lens motor M6 drives the lens 7 to control the copy magnification, the clamp motor M7 drives the clamp plate 2a to open and close, and the return motor M8 drives the optical scanning system (scanner).
And the cleaning motor M9 drives the cleaning unit 20. Main control board 100
Inside, there is a microprocessor, ROM (read only memory), RAM (read / write memory), I / O, A / D converter and so on. The memory unit 170 is a memory provided with a battery backup circuit, for storing data that needs to be retained even when the power of the apparatus is cut off, for example, the values of various parameters set by the color balance setting board OP2. Equipped.

Next, the operation of the color copying machine shown in FIG. 2 will be described. First, a characteristic part will be briefly described. In this example, in the normal mode, mode A, mode B, and mode C, the image forming and transfer processes are performed once for each color of Y, C, and M, but mode D is selected by pressing the mode key KMD. In this case, after the Y, C, and M image forming and transferring processes are performed once according to the characteristics of the mode B (set parameters), the Y, C, and M images are formed again according to the characteristics of the mode C. And each transfer process is performed once. That is, in mode D, image formation and transfer are performed 6 times (in full color mode).

Therefore, if the characteristic A shown in FIG. 6d is set to the mode B and the characteristic B is set to the mode C, by selecting the mode D, recording can be performed with the characteristic of A + B in FIG. 6d.

FIG. 8 shows an outline of the copying machine shown in FIG. This will be described with reference to FIG. When the power is turned on, first the initial settings are made. Specifically, after setting the output port to the initial state and clearing the internal memory, the positions of movable parts such as the scanner, the magnification changing mechanism, and the color separation filter are set to the initial state (home position), and each process control unit is set. Is set to an operable state. The normal mode is selected as the operation mode. In normal mode, display DP2 on operation board OP1
All go out.

After the initial setting, the state of each part (fixing temperature, etc.) is repeatedly checked to wait until it becomes operable.

If there is an abnormality, proceed to abnormality processing. If the preparation is OK, "copy permitted" is displayed on the display portion DP1 of the operation board OP1 and the state check of each portion, key input processing, display processing, etc. are repeatedly executed until the print key K5 is pressed.

The "key input processing" subroutine is shown in FIGS. 9a, 9b and 9c. The "key input process" will be described with reference to the drawings. In this subroutine, the presence / absence of a key input is checked, and if there is a key input, the corresponding processing is performed.

When the numeric keypad KT is turned on, the number of copies is set according to the numerical value assigned to that key. Paper key K2
When is turned on, the paper feed system selected during the copy operation is switched from the upper stage to the lower stage or from the input lower stage to the upper stage. When the magnification key K1 is turned on, the magnification control is performed to switch the magnification.
When the print key K5 is turned on, the print start flag is set.

Next, the processing of the keys related to the density parameter will be described, but before that, the configuration of the memory (a part of the memory unit 170) that stores each parameter will be described. FIG. 11 shows a memory map of that portion. Referring to FIG. 11, this memory block includes memories MI1, MI2, MI3, MN1, MN2, MN3, MA1, MA2, MA3, MB1, MB2, MB3 for each color of Y, C, M. ,
It has MC1, MC2, MC3, MD1, MD2 and MD3. Memory MI
The data being input is stored in n (n = 1 to 3), and
n, MAn, MBn, MCn and MDn have normal mode,
Data of mode A, mode B, mode C and mode D are stored. Of the memories MIn, MNn, MAn, MBn, MCn and MDn, n = 1,
The data stored in the areas of n = 2 and n = 3 correspond to the developing bias voltage, the applied voltage of the main charger, and the exposure amount, respectively.

Referring again to FIGS. 9a, 9b and 9c. Key KG1
When (one of the six keys) is turned on, it is first determined whether the side is up (U) or down (D). On the up side, the content of the memory MI1 (only the one corresponding to the turned-on key among Y, C, and M) is incremented (+1). However,
If the content before updating is 15, that value is retained. On the down side, the contents of the memory MI1 (only the one corresponding to the turned-on key among Y, C and M) is decremented (-1). However, if the content before updating is 0, that value is held.

When the key KG2 (one of the six keys) is turned on, it is first determined whether it is the up (U) side or the down side (D). On the up side, the contents of the memory M12 (only the one corresponding to the turned-on key among Y, C, and M) is incremented (+1). However, if the content before updating is 15, that value is retained. On the down side, the contents of the memory M12 (only the one corresponding to the turned-on key among Y, C and M) is decremented (-1). However, if the content before update is 0, that value is held.

When the key KG3 (one of the six keys) is turned on, it is first determined whether it is the up (U) side or the down side (D). On the up side, the content of the memory MI3 (only the one corresponding to the turned-on key among Y, C, and M) is incremented (+1). However, if the content before updating is 15, that value is retained. On the down side, the contents of the memory MI3 (only the one corresponding to the turned-on key among Y, C and M) is decremented (-1). However, if the content before update is 0, that value is held.

When the keys KG1, KG2 and KG3 are pressed, a predetermined time is waited each time the contents of the memory are incremented or decremented. Therefore, when the keys KG1, KG2, and KG3 are pressed, the value of the memory MIn is repeatedly updated at a rate of 1 in a predetermined time. The range of change is between 0 and 15.

When the memory in key K6 is turned on, the contents of the register R6 are referred to, and the process according to the value is performed. A value corresponding to the operation mode selected at that time is stored in the register R6, and 0, 1, 2, 3 and 4 are respectively in the normal mode,
It corresponds to mode A, mode B, mode C and mode D. In the normal mode, the contents of the memories MI1, MI2 and MI3 are stored in the memories MN1, MN2 and MN3 respectively. In the mode A, the contents of the memories MI1, MI2 and MI3 are stored in the memories MA1, MA2 and MA3 respectively and the mode B is stored. Then memory MI1, MI2 and MI3
Contents in memory MB1, MB2 and MB3 respectively. In mode C, contents in memories MI1, MI2 and MI3 are respectively stored in memories MC1, MC2 and MC3, and in mode D, memory MI1,
The contents of MI2 and MI3 are stored in memories MD1, MD2 and MD3, respectively.

When the mode key is turned on, the following processing is performed according to the pressed mode key. In the case of the mode key KMA, 1 is set in the mode register R1 and the contents of the memories MA1, MA2 and M3 are stored in the memories MI1, MI2 and MI3, respectively. Mode key
For KMB, set 2 in the mode register R1 and set memory MB
The contents of 1, MB2 and MB3 are stored in memories MI1, MI2 and MI3, respectively. Mode key KMC, 3 in the mode register R1
Is set and the contents of the memories MC1, MC2 and MC3 are stored in the memories MI1, MI2 and MI3, respectively. With the mode key KMD,
Set mode register R1 to 4 and set memory MD1, MD2 and M
The contents of D3 are stored in memories MI1, MI2 and MI3, respectively.

That is, when the mode is selected with the mode keys KMA, KMB, KMC or KMD, the parameters of the selected mode are transferred to the memory MIn, and the contents of the memory MIn are the keys KG1, KG2 and KG3.
When the memory in key K6 is pressed, the content of the updated memory MIn is transferred to the memory MNn, MAn, MBn, MCn or MDn according to the operation mode at that time,
Set. Note that once a mode other than the normal mode is selected, the normal mode cannot be selected again without turning off the power.

As described above, when the mode D is selected, the first process (Y, C and M) is executed with the parameter of the mode B, and subsequently the second process is executed with the parameter of the mode C. By updating the parameter of mode B and the parameter of mode C, the parameter of the first process and the parameter of the second process of mode D can be adjusted independently. As a result, the degree of freedom in adjusting the density characteristics (original density-copy density) in mode D is increased.

In the memories MBn and MCn (n = 1 to 3), values such that the combined characteristic (A + B) shown in FIG. 6d is closest to the ideal characteristic are automatically set at the time of initial setting.
At this time, the content of the memory MBn is set to the characteristic that the recording area covers the low density area or the entire area as shown by the characteristic A in FIG. 6d, and the content of the memory MCnb is set as the characteristic B in FIG. 6d. , The recording area is set to a characteristic limited to the high density area. The data to be set at this time is stored in advance in the read-only memory (ROM) of the main control board 100.
Therefore, even if the density parameter is not adjusted after the power is turned on, if the mode D is selected, the theoretically most preferable characteristic is automatically set. It should be noted that all 8 are set in the memory MDn at the time of initial setting.

Referring back to FIG. When the print key K5 is pressed,
That is, when the print start flag is set by the "key input process", the copy process is started.
When the copy process is started, "scanner control", "exposure lamp control", "charge control", "transfer control", "separation control", "developing bias control", "filter control" and "clamper control" subroutines , And other controls are repeatedly executed in a short cycle until copying is completed.

The "scanner control" subroutine will be described with reference to FIG. 10a. First, it is determined whether or not the mode D is selected. That is, since the state of the mode at that time is held in the register R1, the register R1 is referred to and
Whether or not (mode D) is determined. In the case of mode D, the following processing is performed when the content of the counter CN1 is less than 6, and when the content of CN1 is less than 3 in the modes other than mode D, respectively. The content of the counter CN1 is cleared to 0 when starting the copy process.

When the scanner start timing comes, the forward scan drive of the scanner is started. In this example, the scanner is driven by the main motor M1 during forward scanning. When the scanning end timing comes, the forward scanning of the scanner is stopped and the scanner return drive is started. In this example, the scanner drives the return motor M8
Driven by. One of the drive system of the main motor M1 and the drive system of the return motor M8 is selectively connected to the scanner by a clutch (not shown).

When the home position sensor SE8 of the scanner detects the home position, the return drive is stopped and the counter CN1 is incremented (+1). That is, in mode D, scanning is repeated 6 times, and in other modes, scanning is repeated 3 times. Various timings are grasped by counting the number of pulses of a timing generator (not shown) that outputs a pulse synchronized with the driving of the main motor from the start of copying.

The "exposure lamp control" subroutine will be described with reference to FIG. 10b. First, the contents of the register R1 are referred to and the processing corresponding to the value is performed. If the contents of R1 are 0, 1, 2 and 3, the contents of memories MN3, MA3, MB3 and MC3 are loaded into register R2, respectively. If the content of R1 is 4, that is, mode D,
The value corresponding to the contents of counter CN2 is loaded into R2. The content of the counter CN2 indicates the number of times the exposure lamp has been turned on since the start of copying. Therefore, the content of the counter CN2 is cleared to 0 at the start of copying. If the content of the counter CN2 is less than 3, the operation result of MB3 + (MD3-8) is loaded into R2, and if the content of CN2 is 3 or more, the operation result of MC3 + (MD3-8) is loaded into R2.

Next, it is determined whether or not the mode is D. If the mode is D, the following process is executed when CN2 is less than 6, and if the mode is not mode D, the following process is executed when CN2 is less than 3. That is, at the exposure start timing, the dimming level of the exposure lamp 3 is set according to the contents of the register R2, and the exposure lamp is set to ON. At the exposure end timing, the exposure lamp is turned off and the counter CN2 is incremented. Therefore, in mode D, exposure is repeated 6 times, and in modes other than mode D, exposure is repeated 3 times.

As described above, the density parameter set in the mode D, that is, the dimming level is the same as the first process (CN2 = 0).
~ 2) MB3 + (MD3-8), the second process (CN2
= 3 to 5), MC3 + (MD3-8). Therefore, if you adjust the parameter settings in Mode D,
Without adjusting the parameters of Mode B and Mode C
The parameters of both the first and second processes are corrected. The correction amount is given as a deviation from the standard value (8) of the parameter of mode D.

That is, if the parameters of the mode B and the moat C are set in advance so that the combined characteristic (mode D) is close to the ideal characteristic, it is possible to adjust the parameter of the mode D (MD3) as a whole. That is, the characteristics of both the low density region and the high density region can be adjusted. This facilitates adjustment and reduces the number of test copies.

The "charge control" subroutine will be described with reference to FIG. 10c. First, the contents of the register R1 are referred to and the processing corresponding to the value is performed. If the contents of R1 are 0, 1, 2 and 3, the contents of memories M2, MA2, MB2 and MC2 are loaded into register R3 respectively. If the content of R1 is 4, that is, mode D, a value corresponding to the content of counter CN3 is loaded into R3. Counter C
The content of N3 indicates the number of times the charging charger has been energized from the start of copying. Therefore, the content of the counter CN3 is cleared to 0 at the start of copying. If the content of the counter CN3 is less than 3, the operation result of MB2 + (MD2-8) is loaded into R3, and if the content of CN3 is 3 or more, the operation result of MC2 + (MD2-8) is loaded into R3.

Next, it is determined whether or not it is a load D, and if it is mode D, the following processing is executed when CN3 is less than 6, and if other than mode D, the following processing is executed when CN3 is less than 3. That is, at the charging charger energizing start timing, the voltage applied to the charging charger 10 is set according to the contents of the register R3, and the voltage is applied. Also, when it comes to the charging completion timing,
The applied voltage is set to 0 and the counter CN3 is incremented. Therefore, in mode D, the charging charger bias is repeated six times, and in modes other than mode D, the charging charger bias is repeated three times.

As described above, the concentration parameter set in mode D, that is, the voltage applied to the charging charger, is MB + (MD2-8) in the first process (CN3 = 0 to 2) and the second process (CN3 = 3). ~ 5) is MC2 + (MD2-8). Therefore, when the parameter settings are adjusted in mode D, the parameters of both the first process and the second process are corrected without adjusting the parameters of mode B and mode C. The correction amount is given as a deviation from the standard value (8) of the parameter of mode D.

That is, if the parameters of the mode B and the mode C are set in advance so that the combined characteristic (mode D) is close to the ideal characteristic, it is possible to adjust the parameter (MD2) of the mode D as a whole, That is, the characteristics of both the low density region and the high density region can be adjusted. This makes adjustment easier and reduces the number of test copies.

The "transfer control" subroutine will be described with reference to FIG. 10d. First, it is determined whether the mode is D. In the case of mode D, when the value of the counter CN5 is 5 or less, and when the value of CN5 is 2 or less except the mode D, the data corresponding to the value of CN5 is loaded into the register R5 and the register R5 is loaded every time the current is switched. The current value of the transfer charger is switched according to the value of. When switching the current value, the counter CN5 is incremented. The counter CN5 is cleared to 0 at the start of copying. Therefore, the content of CN5 means the number of process executions in the transfer process. When the transfer process is completed 6 times in the mode D, it becomes 3 in the modes other than the mode D.
When the transfer process is completed, the transfer chargers are turned off (current value is 0). In this example, the energizing current of the transfer charger is set as follows.

Other than mode D: Process 1st time (Y) ・ ・ ・ 150μA 2nd time (C) ・ ・ ・ 250μA 3rd time (M) ・ ・ ・ 400μA Mode D: Process 1st time (Y) ・ ・ ・ 150μA 2nd time (C)・ ・ ・ 250μA 3rd (M) ・ ・ ・ 400μA 4th (Y) ・ ・ ・ 250μA 5th (C) ・ ・ ・ 400μA 6th (M) ・ ・ ・ 600μA Current every time the process changes as above The value is updated because when the transfer process is executed, the transfer drum is charged thereby, and the transfer efficiency thereafter is reduced. If no static elimination is performed, it is necessary to sequentially increase the current value in six steps in mode D. In this example, however, intermediate static elimination is performed after the third process, as will be described later. The transfer current is set to a value smaller than that in the third transfer.

The "separation control" subroutine will be described with reference to FIG. 10e. In this subroutine, an AC voltage of 5.5 KV is applied between the separation chargers 22 and 23 at the separation timing, and the voltage is set to 0 at the voltage release timing. At the intermediate charge removal timing, an AC voltage of 4 KV is applied between the separation chargers 22 and 23. When the transfer process is executed, the surface of the transfer drum 2 is charged to the following potential.

1st time ・ ・ ・ About 500V 2nd time ・ ・ ・ 1000 ～ 1500V 3rd time ・ ・ ・ 2000 ～ 3000V So, in this example, when the 3rd transfer process is completed, 4KV AC voltage is applied to the separation charger. It is applied and the transfer drum 2 is discharged. When this intermediate charge removal is performed, the surface potential of the transfer drum drops to 500 to 1000V. Therefore, the transfer current after that can be smaller than that when the intermediate charge removal is not performed. Since the transfer drum 2 is not completely discharged after the intermediate charge removal, the recording sheet is not peeled off from the transfer drum 2 by the intermediate charge removal. When an AC voltage of 5.5 KV is applied to the separation charger, the surface potential of the transfer drum 2 drops to about 0 V, and the recording sheet peels off from the transfer drum 2.

The "developing bias control" subroutine will be described with reference to FIG. 10f. First, the contents of the register R1 are referred to and the processing corresponding to the value is performed. If the contents of R1 are 0, 1, 2 and 3, then the memories R1, M1, MB1, and MC1 are stored in the register R4.
Load the contents of. The content of R1 is 4, that is, mode D
If so, a value corresponding to the contents of counter CN4 is loaded into R4. The content of the counter CN4 indicates the number of process executions from the start of copying in the developing process. Therefore, the content of the counter CN4 is cleared to 0 at the start of copying. If the content of counter CN4 is less than 3, MB1 + (MD1-
The operation result of 8) is loaded into the register R4, and if the content of CN4 is 3 or more, the hydrochloric acid result of MC1 (MD1-8) is loaded into R4.

Next, it is determined whether or not it is mode D. If it is mode D, the following processing is executed when CN4 is less than 6, and if other than mode D, the following processing is executed when CN4 is less than 3. That is, at the development bias voltage application timing, the applied voltage is set according to the contents of the register R4 and the voltage is applied to the development electrode. At the voltage release timing, the applied voltage is set to 0 and the counter CN4 is incremented. Therefore, in mode D, voltage application is repeated 6 times,
In modes other than mode D, voltage application is repeated three times.

As described above, the density parameter set in the mode D, that is, the developing bias voltage, is set in the first process (CN4
= 0 to 2), MB1 + (MD1-8), and in the second process (CN4 = 3 to 5), MC1 + (MD1-8).
Therefore, when the parameter setting is adjusted in the mode D, the parameters of both the first process and the second process are corrected without adjusting the parameters of the mode B and the mode C. The correction amount is given as a deviation from the standard value (8) of the parameter of mode D.

In other words, if the parameters of the mode B and the mode C are set in advance so that the combined characteristic (mode D) is close to the ideal characteristic, it is only necessary to adjust the parameter (MD1) of the mode D, That is, the characteristics of both the low density region and the high density region can be adjusted. This facilitates adjustment and reduces the number of test copies.

The "filter control" subroutine will be described with reference to FIG. 10g. In this subroutine, the content of the counter CN1 that holds the number of times of scanning by the scanner is referred to, and the color of the color separation filter 9 is selected according to the result. That is, the counter
If CN1 is 0 or 3, it is checked whether the position of the color separation filter is the home position, and if not, the filter motor M5 is driven until the home position is detected.
When the home position is reached, stop the filter motor M5 and clear the counter CN6 to zero. If the counter CN1 is 1 or 4, the contents of the counter CN6 are checked. If CN6 is not 1, drive the filter motor M5 and set the color separation filter 9
Is rotated 120 degrees and the content of the counter CN6 is incremented. If the counter CN1 is 2 or 5, check the contents of counter CN6. If CN6 is not 2, filter motor M5
Is driven, the color separation filter 9 is rotated by 120 degrees, and the content of the counter CN6 is incremented.

As a result, when the counter CN1 is 0 or 3, the blue (B) filter plate is inserted into the optical path and the counter CN1
Is 1 or 4, the red (R) filter plate is inserted in the optical path, and when the counter CN1 is 2 or 5, the green (G) filter plate is inserted in the optical path.

The color copying machine shown in FIG. 2 can also perform a monochrome copy operation of any one of Y, C, and M, but the monochrome mode is omitted in the flowchart shown in the drawing.
In the single color mode, one image forming and transferring process is performed for one copy, but as in the full color mode, two processes can be repeated for a single color copy.

FIG. 1 and FIG. 7 show operation timings in mode D and other modes, respectively. Referring to FIG. 1, it can be seen that in mode D, the scanner scanning, the exposure process, the charging process, the developing process, the transfer process, etc. are repeated six times in one copy cycle. On the other hand, in the operation mode shown in FIG.
It can be seen that the scanner scan, the exposure process, the charging process, the developing process, the transfer process, etc. are repeated three times in one copy cycle. By selecting Mode D, a very good quality copy can be obtained, but because the image forming and transfer process is repeated 6 times,
The copy speed is quite slow. Therefore, when the copy speed becomes a problem, by selecting an operation mode other than mode D, copying can be performed in about half the time of mode D.

By the way, conventionally, there was a case in which density unevenness like that swept by rice ears appeared on the recorded image along the scanning direction of the copying machine (the rotating direction of the tourist drum). When the rotation mode (mode in which the process is performed twice for each color) is selected, the development is not observed. That is, by performing the recording process a plurality of times for the same color, the occurrence of density unevenness is eliminated.

The meanings of the special symbols shown in the drawings are as follows.

HP ... Home position (home position) PP ... Power pack (power supply) SOL ... Solenoid MC ... Electromagnetic clutch In the above embodiment, the light emission level of the exposure lamp is used as a parameter related to image reading. However, it is also possible to provide a light amount narrowing means in the optical path of the optical forehead scanning system and use the narrowed amount as a parameter.

In the above embodiment, the case of an analog color copying machine is shown, but the present invention can be similarly applied to other various recording apparatuses that perform the similar electrostatic transfer recording process.

[Effect] As described above, according to the present invention, the adjusted parameter value is based on the respective parameter values of the plurality of development colors (Y, M, C) actually used before the adjustment. Since it is set for each developing color, even if the operator does not remember the value before adjustment, for example, the operation of adjusting the density in the direction of making it one step darker than before can be easily performed for each developing color. Therefore, it is very easy to adjust the color balance. This makes it possible to easily make fine adjustments to the image quality.

[Brief description of drawings]

FIG. 1 is a timing chart showing an operation example in mode D of the color copying machine of the embodiment. FIG. 2 is a front view showing the structure of the mechanical portion of the apparatus of the embodiment. 3a and 3b are perspective views showing a part of the apparatus shown in FIG. 4a and 4b show the operation board OP of the device shown in FIG.
FIG. 3 is a plan view showing appearances of 1 and a color balance setting board OP2. 5a, 5b, 5c, 5d and 5e are block diagrams showing the electrical circuit arrangement of the device of FIG. FIGS. 6a, 6b and 6c are graphs showing changes in original density-copy density characteristics when the developing bias voltage, the exposure amount and the charging voltage are changed, respectively. FIG. 6d is a graph showing a method for making the original density-copy density characteristics closer to the ideal characteristics. FIG. 7 is a timing chart showing an operation example of the apparatus of FIG. 2 in the normal mode. Figure 8, Figure 9a, Figure 9b, Figure 9c, Figure 10a, Figure 10b,
Figures 10c, 10d, 10e, 10f and 10g
3 is a flowchart showing the operation of the electric circuit of the device shown in FIG. 2. FIG. 11 is a memory map showing a part of allocation of each memory of the memory unit 170. 1: Photosensitive drum (charge carrier) 2: Transfer drum, 2a: Clamp plate 2b: Cam mechanism, 3: Exposure lamp 4: First mirror, 5: Second mirror 6: Third mirror, 8: Fourth mirror 7: Lens, 9: Color separation filter 10: Charging charger, 11: Eraser 12,13, 14: Developing roller (developing means) 18: Transfer charger (transfer means) 20: Cleaning unit 21: Static eliminator charger 22, 23: Separation Charger 26, 27: Paper feed cassette 28: Calling roller, 29: Paper feeding roller 30: Reverse rotation roller, 31: Registration roller 32: Fixing roller, 41: Recording sheet 42: Transmission mechanism, 45, 46: Gear OP1: Operation board OP2: Color balance setting board K5: Print key K6: Memory in key KMB: Mode selection key (first setting means) KMC: Mode selection key (second setting means) KG1, KG2, KG3: keys DP1, DP2, DP3 : Display 100: Main control board (electronic control means) 170: Memory unit 190: Lamp regulator M1: Main Motor, M2: Register motor M3: Paper feed motor, M4: Paper feed table motor M5: Filter motor, M6: Lens motor M7: Clamp motor, M8: Return motor M9: Cleaning motor SE5, SE6, SE7, SE8: Home position Sensor

Continuation of the front page (56) References JP-A-60-207159 (JP, A) JP-A-60-207160 (JP, A) JP-A-59-164564 (JP, A) JP-A-59-33462 (JP , A) JP 60-75846 (JP, A) JP 48-17335 (JP, A) JP 56-22464 (JP, A) JP 59-223067 (JP, A) JP 60-75844 (JP, A) JP-A-60-121479 (JP, A) JP-A-60-222874 (JP, A) JP-A-60-126673 (JP, A) JP-A-60-126668 (JP, A) A) JP 60-126672 (JP, A) JP-B 5-79990 (JP, B2) JP-B 5-38948 (JP, B2) JP-B 63-787 (JP, B2) JP-B 5 -24513 (JP, B2) JP-B 6-46330 (JP, B2) JP-B 6-46329 (JP, B2)

Claims (1)

[Claims] 1. A charge carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the charge carrier; arranged in proximity to the charge carrier and having a plurality of color developers. Developing means for visualizing the electrostatic latent image with the developers of a plurality of colors; Transfer means for transferring the image visualized by the developing means to a predetermined recording sheet; and electrostatic latent image on the charge carrier. A process control means for performing a recording process of forming a latent image by visualizing the electrostatic latent image and transferring the visible image onto a recording sheet according to a parameter set for each color of the plurality of colors of developer; In an electrostatic transfer type color recording apparatus including: a plurality of parameter storage means for respectively holding the values of the parameters for each color of the plurality of colors of developer; a temporary storage means; Parameter storage means holds Memory transfer means for transferring a plurality of values as a unit to the temporary storage means; a plurality of sets of increase / decrease instruction means provided in association with respective colors of the developers of the plurality of colors; In response to the input operation of the instruction means, the increase / decrease processing means for increasing / decreasing the value held by the temporary storage means for the color associated with the input / output increase / decrease instruction means of the plurality of sets of increase / decrease instruction means And a registration instruction means for transferring the value held in the temporary storage means to the parameter storage means in units of the plurality of colors in response to an input operation. Color recording device.