JPS58152266A - Adjuster for color balance in copying device - Google Patents

Abstract

PURPOSE:To reproduce the picture image density of originals by setting the quantity of light of a light source, the electrostatic charging quantity of electrifiers, and the bias voltage of a developing device in accordance with the picture image density of the original. CONSTITUTION:In the stage of color copying with a copying device which transfers the picture images of respective color components superposedly on transfer paper by electrostatic charging, exposing and developing for each of the color components separated from the light images of a color original with filters, the quantity of electrostatic charging, bias voltage and the quantity of light in the image forming stage for respective separated colors of yellow Y, magenta M and cyan C are first set by operating dials 31-39 for setting properly in an operation panel 51 for adjusting color balance, and are stored in a nonvolatile storage element 54 of a controller 52. In the respective stages of copying, the set values of the color balance are fed through a microcomputer 53 to high voltage transformers 55-57, and the quantity of electrostatic charging, the quantity of light and developing bias potential are controlled to the colors corresponding to the colors in said stages.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color balance adjustment device for adjusting the density of each color component image in a color uniform copying device.

When copying in color, this method is suitable for documents with different image densities for each color component, such as documents with many blue edges such as maps, documents where skin tones should be emphasized such as people, documents with many line drawings, etc. In many cases, it is required to perform color copying with optimum image density for each color component. In such a case, it is necessary to adjust the density of each color component image each time the document changes.

In color copying devices, methods have been proposed in which the density of each color component image is adjusted by adjusting the amount of transmitted light using a filter, and the amount of charge and exposure is controlled according to the density difference of each color based on one color. However, the image density of each color component is affected by the amount of exposure, the amount of negative charge, the developer concentration, and even the amount of charge removed, making it difficult to reproduce the image density of the original.

The present invention solves the above problems by setting and storing the light intensity of the light source, the amount of charge of the charger, and the bias voltage of the developing device according to the image density of the original, and sets and stores the above conditions for each color printing process. The object of the present invention is to provide a device that performs control according to a set storage amount.

The details of the present invention will be explained with reference to embodiments shown in the figures.

In FIG. 1, a photosensitive drum 1 and a transfer drum 2 are arranged to face each other at a transfer position, a light source 3 illuminates an original on an original platen 6, and light reflected from the original is reflected by a mirror 4.24. The light is reflected by the mirror 25.5, and the light emitted from the lens 8 is further reflected by the mirror 25.5.
The colors are separated by the color separation filter 9 and the photosensitive drum 1
is projected onto the exposure position. While the photosensitive drum 1 rotates, it is primarily charged by a charger 7, and light is projected at the exposure position to form an electrostatic latent image of a color-separated optical image of the original, which is then processed by a developer corresponding to the color separation. Visualized. For example, when an 11 blue "filter" is used as the color separation filter 9, a yellow visible image is produced by the developing device 10 having a "1" yellow toner, and when a "green" filter is used, a developing device having a "magenta" toner is produced. A magenta visible image is formed by 11, and a cyan visible image is formed by a developing device 12 having cyan toner 11 when a "red filter" is used.

The image visualized on the photosensitive drum 1 in one of the three colors is transferred onto the transfer paper 14 at the transfer position. The transfer paper 14 is fed from the cassette 13 by the paper feed roller 15, and is sent to the transfer drum 2 at an appropriate timing by matching the timing with the registration rollers 16.The leading end is clamped by the clamper 17 of the transfer drum 2, It passes through the transfer position. When the transfer paper passes through the transfer position, the visible image on the photosensitive drum 1 is transferred onto the transfer paper under the action of the transfer charger 18.

Each rotation of the photosensitive drum 1, the color separation filter 9 and the developing device 10, 11, 12 are switched, and color separation light images of different colors are formed one after another on the transfer paper sent by the transfer drum 2. Images of different colors are transferred in a superimposed manner with each rotation, and color separation images of three colors are superimposed and transferred onto the transfer paper by three rotations.

When the separated three-color images are superimposed, the transfer paper 14 is separated from the transfer drum 2 under the action of a separation static eliminator 19 and a separation claw 20, fixed by a fixing roller 21, and discharged onto a tray 22.

When making a color copy using the copying apparatus shown in FIG. 1, the amount of charge, bias voltage of the developing device, and amount of light in the image forming process for each separated color of yellow, Y1, magenta, M1, and cyan C is used in the color balance adjustment operation panel 51 shown in FIG. Set.

That is, the first charging dial 31 is used to set the amount of charge of the charger 7 in the yellow image forming process, and similarly, the second and third charging dials 32 and 33 are used to set magenta, magenta, and magenta, respectively.
The amount of charge of the charger 7 in the cyan image forming process is set. Further, the first bias dial 34 sets the bias voltage of the developing device 10 in the yellow image forming step, and the second bias dial 35 and the third bias dial 36 set the bias voltages of the magenta developing device 11 and the cyan developing device 12, respectively. . Furthermore, the first light source dial 37, the second light source dial 38, and the third light source dial 39 each
The light intensity of the light source 3 in the yellow, magenta, and cyan image forming steps is set. Using the setting dials 31 to 39 on the color balance adjustment operation panel 51, the amount of charge in image formation for each color,
After setting the developing bias voltage and light intensity, press setting switch 4.
By pressing 0, the values specified by each of the setting tiles 31 to 39 are stored in the nonvolatile memory element 54 by the operation of the microcomputer 53 and the nonvolatile memory element 54 in the controller 52 shown in FIG.

Check switch 41 of color balance adjustment operation panel 51
When pressed, the display 42 displays the setting amount such as yellow image forming charge amount, and the display 43 displays the setting amount for the type of condition displayed on the display 42 in the manner described below.
You can check the stored setting conditions.

In FIG. 3, a controller 52 including a micrometer 53 and a non-volatile memory element includes a high voltage transformer 55 that controls the charger 7, a high voltage transformer 56 that controls the developing devices 10, 11 and 12, and a lamp regulator that controls the light source 3. 57.

As shown in FIG. 4, a color balance selection operation panel 58 is provided in a part of the operator operation panel, and selection switches 61 to 65 are provided for selecting and setting conditions according to the color tone of the original. One destination selection display lamps 66 to 70 are provided corresponding to the respective destinations.

To operate the color copying apparatus, first, a color tone is selected and set using the color balance selection operation panel 58. For example, the selection switch 61 is used to set the color tone of an original such as a map with a lot of blue or green, and the selection switch 62 is used to set the color tone of an original such as a person whose skin tone is to be emphasized. The color tone of the original is made to correspond to the selection switches 61 to 65, and if you want to copy the map original now, press the selection switch 61.
It is confirmed by the selection display lamp 66 that the map document is selected.

Next, a map original to be copied is placed on the original table 6.

The first step is to set each condition for a map manuscript.

For this purpose, the setting dials 31 to 39 on the color balance adjustment operation panel 51 are operated as appropriate to select the conditions considered to be optimal, and the setting switch 40 is pressed. As a result, the currently selected conditions are stored in the nonvolatile storage element 54 via the microcomputer 53-4 of the controller 52 as the copying conditions for the map manuscript, ie, in the case of the selection switch 61.

Next, when the copying start button on the operation panel (not shown) is pressed, the copying device performs the steps of charging, exposing, developing, paper feeding, zeroing, and fixing for each separated color as previously explained in FIG. The color balance setting value stored in the non-volatile memory element 54 is passed through the microcomputer 53 to set the charge amount to the high voltage transformer 55 during charging, the lamp light amount to the lamp regulator 57 during exposure, and the developing bias to the high voltage transformer 56 during development. The potential is specified and controlled as a value according to the color at that time. If the copy obtained in this manner is satisfactory, the set value is used as the setting condition in the selection switch 61 for subsequent copies; however, if the copy is not satisfactory, the setting dial 31 to 3
After changing the value of 9 and resetting the conditions using the setting switch 4o, the above copying is performed, and the process is repeated until a satisfactory copy is obtained. Once the optimum reproduction conditions are set for the selected original color tone, copying will be automatically performed under the optimum color tone reproduction conditions by simply pressing the selection switch 61 or the like.

Similarly, in the case of an original with a tone in which it is desired to emphasize the skin tone of a person, for example, the optimum reproduction conditions are set in the same manner as described above with the selection switch 62 in the depressed state.

Each selection switch 63 can also be used for different color tone conditions.
The optimum reproduction conditions are set under the action of steps 65 to 65, and subsequent copies of various tones can be made under the optimum conditions with simple operations.

That is, an appropriate switch is selected from selection switches 61 to 65 and pressed depending on the color tone of the original to be copied. The selected color tone is lit by the selection display lamps 66 to 70.
This can be confirmed by

After confirming that the selection is correct, by pressing the copy start button, copying is performed under the optimum conditions previously stored in the non-volatile memory element 544C, and a copy of the optimum image with the desired color balance is obtained. .

Regarding light amount control as a specific example of control by the color balance adjustment system shown in FIG. 3, as shown in FIG.
A D-A converter 82 converts it into a digital analog quantity. The voltage from the light source AC power supply 83 is reduced by the voltage conversion transformer 84, passed through the rectifier circuit 85 and the smoothing circuit 861, and sent as a DC voltage to the comparator circuit 87, where it is compared with the analog signal of the instruction signal by the computer. Then, a triax 89 for switching the light source voltage is activated via the drive circuit 88 to control the light amount of the light source 90 to a specified light amount. If the voltage of the AC power supply for the light source is lower than the optimum reproduction conditions sent from the D-A converter 82, the drive circuit 88 is driven, the triac 89 is made conductive, and voltage is supplied to the light source 90, and at the same time it is fed back to the power supply 83. It acts to increase the output of the rectified and smoothed DC voltage 86. In this way, the inputs of the voltage comparator circuit 87 are controlled to be the same.

Control is performed in the same manner even when the AC power source for the light source is higher than the optimum reproduction conditions.

If it is desired to check the current color balance settings prior to copying, the user selects and presses the color tone to be checked from among the selection switches 61 to 65 in FIG. 4. As a result, the color tone to be confirmed is displayed by the lit lamps among the selection display lamps 66 to 70. Next, the check switch 41 of the color balance adjustment operation panel 51 shown in FIG. 2 is pressed. When you press the check switch 41 once, the display 42K r I J will change from ``1'' to ``2'' depending on the number of presses, such as ``2'' when you press the check switch 41 twice.
Displays any number up to 9. In this case the number "1"
- "9" are displayed sequentially from setting dials 31 to 39, respectively, "1" is a yellow charging dial, the first charging dial 31:, and r2J is a magenta charging dial, the second charging dial. Similarly, ``8'' is a magenta light source dial and the second light source dial 384-119'' is a cyan light source dial.39 third light source dials are displayed. In this way, when the check switch 41 is pressed once, the number 1 is displayed on the display 42, and at the same time the setting is stored on the display 43. The yellow charge amount data is converted into numbers and displayed.

When the check switch 41 is pressed once again, the number "2" is displayed on the display 42, and at the same time, the magenta charge amount data is displayed on the display 43. When the check switch 41 is pressed nine times in this manner, the number "9" is displayed on the display 42, and at the same time, the amount of cyan light is converted into a number and displayed on the display 43. The numbers of the setting data displayed on the display 43 can be displayed on the setting dials 31 to 39 using equally divided scales so that the numbers on the scales match the numbers on the display 43. 39 makes it easy to operate when resetting numerical values for each condition.

According to the present invention, each color separation can be easily set using a dial according to the charge amount, developing bias voltage, light amount, and each color tone to be reproduced. It is now possible to form images and sounds for each color component with the optimum image density for each color tone.

For example, since it is possible to memorize and set each color in terms of charge amount, developing bias voltage, light amount, etc., the color tone of the copied original can be reproduced better.

According to the present invention, it is easy to set, modify, and change each condition, and furthermore, it is easy to confirm the current setting conditions, so that it is possible to always optimally match the color tone of the original to be used.

In the color balance adjustment system shown in FIG.
The setting value signal sent to the microcomputer 3 can be either a digital quantity or an analog quantity, and in the case of an analog quantity, a D converter is required before and after the microcomputer 53, but there is an advantage that the number of signal lines is reduced.

The color balance adjustment operation panel has only nine setting dials, and an example is shown in which settings for a predetermined color tone are made in combination with the selection switch on the color balance selection operation panel shown in Figure 4.Color balance adjustment It is also possible to provide setting dials on the operation panel in sets corresponding to the number of selection switches, and each dial to set which condition amount for which color tone can be set completely fixedly.

In this case, the number of dials increases, but all 11: settings can be made for all color tones with a single operation of one setting switch 40. In this case, the check switch 41
There is no need for display devices 42 and 43, and the current conditions can be read at all times using all dials. Also, in this case, the microcomputer 53 and the nonvolatile memory element 54
It becomes possible to control the high voltage transformer 55, 57 and the lamp regulator 56 directly from the color balance adjustment operation panel without going through it.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram illustrating a copying apparatus according to the present invention, FIG. 2 is a plan view of a color balance adjustment operation panel, FIG. 3 is a configuration diagram of an example of a color balance adjustment system, and FIG. 4 is a color balance selection operation panel. FIG. 5 is a block diagram of an example of a light source control device. 1... Photosensitive drum 2... Transfer drum 3...
・Light source 7... Charger 10, 11.12
--Developing device 14...Transfer paper 18...Transfer charger 31-39...Setting dial (means for adjusting setting conditions) 40...Set switch 41...Check switch 42, 43... ...Display unit 51...Color balance adjustment operation panel 54-...Nonvolatile memory element

Claims (3)

[Claims] (1) Light image of a color original In a copying device that charges, exposes, and develops each color component that has been separated into all colors, and transfers each color component image onto transfer paper, each color component, such as the amount of charge, development bias potential, and amount of light, is used. A copying apparatus characterized by having means for adjusting a plurality of setting conditions for setting image density and means for selecting and setting the color tone of an original, so that image density setting conditions can be set in advance for each original color tone. Color balance adjustment device. (2) In a copying device that charges, exposes, and develops each color component of the color separated light image of a color original, and transfers the images of each color component onto transfer paper in an overlapping manner, each color component such as the amount of charge, development bias potential, amount of light, etc. means for adjusting a plurality of setting conditions for setting image density; means for selecting and setting the color tone of the original; a non-volatile memory element for storing values set by the adjusting means and the setting means; and selecting and instructing the color tone of the original. 1. A color balance adjustment device for a copying machine, comprising means for adjusting the color balance of a copying machine. (3) In a copying machine that separates the light image of a color original into each color component, charges, exposes, and develops each color component image, and transfers each color component image onto transfer paper in an overlapping manner, each color component image, such as charge amount, development bias potential, light amount, etc. means for adjusting a plurality of setting conditions for setting the density; means for selecting and setting the color tone of the original; a non-volatile memory element for storing the values set by the adjusting means and the setting means; and a selection instruction for the color tone of the original. A color balance adjustment device that controls the conditions of the charging, developing device, light source, etc. of the copying machine to the density setting conditions of the specified color tone.