JPS59129874A - Color tone adjusting device of color copying machine - Google Patents

Abstract

PURPOSE:To adjust easily the reproducibility of a color tone so as to suit it to a user's taste by providing a means for controlling the developing potential in case of development by cyan, magenta and yellow developing materials in acordance with a set value of an operating part for adjusting the reproducibility of a color tone. CONSTITUTION:A titled device is provided with an operating part 9 for adjusting the reproducibility of a color tone, and a means for controlling the developing bias potential in case of development by cyan, magenta and yellow developing materials in accordance with a set value of the operating part 9. In this regard, since each filter 15-17 is driven by a stepping motor 18, the set position accuracy of the filters 15-17 is high, and also since a multi-layer film interference filter is used for the filters 15-17, they are hardly influenced by the temperature and humidity as compared with a geletine filter, etc. As a result, the color tone reproducibility can be adjusted easily by a user, and a color tone of a copy can be adjusted so as to suit it to a user's taste.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for adjusting the tone of a copy in a color copying machine that has cyan, magenta, and yellow developing materials and develops three colors with each of the developing materials by rotating a photoreceptor multiple times. It is something.

It is preferable that the color tone of copies made by a color copying machine not only faithfully reproduce the original, but also match the user's preference.

In other words, it is preferable that the color tone reproducibility of a color copying machine be adjusted according to the user's preference.

However, the color tone reproducibility of conventional color copying machines is constant, and the color tone of copies cannot be adjusted to match the user's preference.

The present invention was made in view of the above circumstances, and its purpose is to provide a color reproduction system that allows the user to easily adjust the color reproducibility and adjust the color tone of the copy to suit the user's preference. An object of the present invention is to provide a color tone adjustment device for a copying machine.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic explanatory diagram of a color copying machine.A charger 3, an exposure device 4,
・The developing device 5, the bias transfer roll 6, the cleaning device 7, etc. are arranged in this order, and the cyan developing material C.
Yellow developer Y and magenta developer M are provided. Then, the surface of the photoreceptor 20 is uniformly charged with the charger 3, and the optical image of the document is exposed to the photoreceptor 2 through a green filter in the exposure device 4, thereby creating a potential pattern (latent image) on the photoreceptor 2. The magenta developing material M in the developing device 5 develops the image into a visible image.

This visible image is transferred onto a sheet of paper wound around a bias transfer roll 6.

Meanwhile, the surface of the photoreceptor 2 is cleaned by the cleaning device 7, and the above-described process is repeated for the blue filter (yellow developer) and the red filter (cyan developer).

In the above steps, after the visible image developed with magenta, yellow, and cyan developer material is transferred to the paper wound around the bias transfer roll 6, the paper is transferred to the bias transfer roll 6.
The copy is peeled off from the paper, sent to a fixing device 8, and fixed to form a color copy.

In FIG. 1, a color tone reproducibility adjustment operation section 9 is installed in a copying machine main body 1 so as to be easily operated by a user from the outside.

The exposure section 4 is constructed as shown in FIG. 2, and has a light source (that is, a slit exposure type light source) covered with a reflector 11 facing the document placement table 1 provided in the copying machine main body 1. 12 is provided to irradiate the original 13, and its reflected optical path (that is, a light image from the original 13) 14 is exposed to the photoreceptor 2.

A green filter 15, a blue filter 16, and a red filter 17 are installed in the shape of paddles at positions crossing the optical image 14, and are configured to be rotatable by a stepping motor 18, so that any filter 15, 16, 17 can be rotated. It is designed so that it can be installed at a position crossing the optical image 14 while changing the angle α formed with the optical image 14.

Each of the filters 15, 16, 17 is a multilayer interference filter, and depending on the angle α with respect to the optical image 14, the filters 15a, 15'a, 16a, 16'a shown in FIG.
, 17a and 17'a, the spectral transmittance changes.

The functional relationship between the angle (inclination angle) to the optical image 14 and the cutoff wavelength at this time is as shown in FIG.

As described above, by changing the angle α of each filter 15, 16, 17 with respect to the optical image 14, the amount and quality of light irradiated to the photoreceptor 2 differs. The density of the developed visible image can be adjusted. In other words, since the color reproduction of the color copying machine can be adjusted, the color tone of the copy can be adjusted.

As shown in FIG. 5, the color tone reproducibility adjustment operation section 9 is equipped with red, blue, and yellow density adjustment levers 20, 21, and 22, so that the user can operate it to the dark side or light side according to his/her preference. It is composed.

The positions of the concentration adjustment levers 20, 21, and 22 are converted into voltages by the arithmetic circuit section 23 as shown in FIG.
The converter 24 converts the % and sends it to the calculation unit (microcomputer) 25 to calculate and output the driving pulse P to the stepping pulse motor 18, which calculates the angle of each filter 15, 16, I7 with the optical image 14, and calculates the density. The operation is controlled so that the angle matches the position of the adjustment levers 20, 21, and 22.

Next, the operation of adjusting color tone will be explained.

First, the density adjustment levers 20, 21, 22 shown in FIG.
The user can change the color tone to his/her preference.

As a result, the set density adjustment levers 20, 21, 22
Depending on the position, the stepping motor 1g is driven by the arithmetic circuit shown in FIG. 6, and the position M of the paddle-shaped filters 15, 16, and 17 of the exposure section 4 shown in FIG. 2 is determined.

At this time, the angle α of the paddle-shaped filters 15, 16, and 17 with respect to the optical image 14 changes, and the spectral transmittance of the filter changes from 15'a to 16'a in FIG.
・Changes like 17'a.

This allows the photoreceptor 2 to adjust the quality of light after passing through the filter.
The effective amount of light changes, and the potential on the photoreceptor changes.

As a result, the toner density of each color to be developed changes, and the color tone reproducibility in copies changes.

For example, if the red density adjustment lever 20 is set to the center, the blue density adjustment lever 21 is set to the light side end, and the yellow density adjustment lever 22 is set to the dark side end, then these density adjustment levers 20 and 22 are set to -. The set positions 21 and 22 are calculated using a preset calculation table 25a shown in FIG. 6, and determine the rotation angle of the stepping motor 18.

At this time, the stopping positions of each filter 15, 16, and 17 are determined as follows.

Since the red density adjustment lever 20 is located at the center, the green filter 15 is set to stop at a position of 90 degrees with respect to the optical image, and as a result, the filter spectral transmittance is as shown in FIG. 3, 15a.
The cutoff wavelength on the long wavelength side is 600 wn
becomes.

Blue density adjustment lever 2I is at the thin end/yellow density adjustment lever 2
2 is the dark side end, the red filter 17 and blue filter 16 are set to stop at a predetermined angle α0 position with respect to the optical image, as shown in FIG.
It has the spectral transmittance characteristics of +6b and +7b in the figure,
As shown in FIG. 4, the cutoff wavelength shifts to the shorter wavelength side.

As a result of determining the spectral characteristics of each filter 15, 16, and 170 as described above, the effective amount of light on the photoreceptor 2 is as follows.

For the green filter 15, the angle α with respect to the light image is 9
Since it is 0 degrees, the effective amount of light on the sensitive material surface is equivalent to that of a conventional color process.

On the other hand, since the red filter 17 and the blue filter 16 are installed at an angle with respect to the optical image, their cutoff wavelengths are shifted to the shorter wavelength side, and the photoreceptor surface is lower than when they are installed at 90 degrees. The effective light amount increases for light passing through one red filter, and decreases for light passing through red filter 16.

Therefore, the surface potential of the photoreceptor and the amount of development during three-color toner development are as follows.

During development with the magenta developer, the effective amount of light on the photoreceptor surface by the green filter 15 is the same as in the conventional case, so both the photoreceptor surface potential and the amount of development by the magenta developer are the same as in the conventional case.

On the other hand, during development with the cyan developer, the effective amount of light by the red filter 17 increases compared to the conventional case, so the surface potential of the photoreceptor decreases and the amount of development with the cyan developer decreases.

Also, when developing with yellow developer, use a blue filter.
Since the effective amount of light by 16 is reduced compared to the conventional case, the surface potential of the photoreceptor increases and the amount of development by the yellow developer increases.

This results in a copy with a strong yellow and weak blue tone.

Note that each color density adjustment lever 20 of the color tone reproducibility adjustment operation section 9
- By controlling the developing bias potential (not shown) in the developing device 5 shown in FIG. 1 when developing with cyan, magenta, and yellow color developing materials for the 21 and 22 setting values, respectively. , color tone reproducibility can be adjusted in the same way as described above.

That is, 3. the color tone reproducibility adjustment operation section 9;
It is sufficient to provide means for controlling the development potential (photoreceptor surface potential and development bias potential of the developing device) during development with cyan, magenta, and yellow developing materials according to the set values of .

Note that, according to the illustrated embodiment, the stepping motor 18
Since each filter 15, 16, 17 is driven by
The setting positional accuracy of the filters 15, 16, and 17 is high, and since the filters 15, 16, and 17 use multilayer interference filters, they are less susceptible to temperature and humidity effects than gelatin filters and the like.

With the present invention as described above, the user can easily adjust the color tone reproducibility, and the color tone of the copy can be adjusted according to the user's preference.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic illustration of a color copying machine, FIG. 2 is an illustration of an exposure section, and FIG. 3 is a table showing changes in spectral transmittance depending on the angle of the filter with respect to the optical path. 4 is a table showing the relationship between the angle of the filter with respect to the optical path and the cutoff wavelength, FIG. 5 is a plan view of the color tone reproducibility adjustment operation section, and FIG. 6 is a calculation circuit diagram. 9 is a color tone reproducibility adjustment operation section. Applicant Fuji Xerox Co., Ltd. Agent Ben! Masaaki Yonehara Patent Attorney Tadashi Hamamoto Figure 1 Figure 2 Figure 3 @ Figure 4 CuT oFF 4jL Figure 5

Claims (1)

[Claims] In a color copying machine that performs three-color development using cyan, magenta, and yellow developing materials, there is a color tone reproducibility adjustment operation section 9, and when developing using cyan, magenta, and yellow developing materials, according to the setting values of the operation section 9. 1. A color tone adjustment device for a color copying machine, comprising means for controlling a developing potential of a color copying machine.