JPH0273340A - Color adjusting device for copying machine - Google Patents

Abstract

PURPOSE:To easily adjust the color of a copied image and to prevent incorrect absorption by using an electronic shutter divided into three areas, simultaneously arranging color filters at the respective areas and independently changing the duty cycles of driving pulses driving the respective areas every color. CONSTITUTION:The electronic shutter 17 which is arranged nearly at the pupil position of an exposure optical system and has the three areas whose light transmittivity is independently changed and three kinds of the color filters 18 arranged corresponding to the respective areas of the electronic shutter 17 are provided. Besides, a pulse generating means 39 which generates the pulses for driving the respective areas of the electronic shutter 17 and a means 35 which changes the duty cycles of the pulses every color are provided. Then, though the respective areas of the electronic shutter 17 are driven by the driving pulses, the duty cycles of the driving pulses are independently adjusted every color. Thus, the color of the copied image can be adjusted and the incorrect absorption can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color adjustment device used in silver halide photocopying machines, such as photoprinting machines and copiers.

(Prior Art) In a silver halide photocopying machine, color adjustment is performed to improve the color balance of a copied image. As a conventional color adjustment device, for example, Japanese Patent Publication No. 44-2542
As described in the publication, two color filter plates that can be slid freely in the direction perpendicular to the optical path and a variable diaphragm are arranged between the front group lens and the rear group lens, and a variable aperture is arranged between the front group lens and the rear group lens to There are known devices that adjust the quality and amount of light. This color filter plate has a transparent center and three primary colors A on both sides.

Colored with two colors, B or C, of which A is 2 colors.
Used in color filter plates. By sliding these two color filter plates independently, it is possible to insert up to two types of color filters into the optical path and perform color adjustment.

[Problem that the invention seeks to solve]

In the color adjustment device described above, since two color filter plates are slid and inserted into the optical path, there is a problem that the mechanism becomes quite complicated. In addition, with movable color filters,
When two color filters overlap, incorrect absorption occurs in this area, and in order to correct this, it is necessary to correct the insertion amount of the color filter plates.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color adjustment device for a copying machine that is easy to configure and control.

Means for Solving Problems] In order to achieve the above object, the present invention has three areas arranged approximately at the pupil position of the exposure optical system and whose light transmittance changes independently. An electronic shutter, three types of color filters arranged to correspond to each area of the electronic shutter, a pulse generating means for generating pulses for driving each area of the electronic shutter, and a duty cycle of this pulse. and a means for changing the color for each color.

[Effect]

Each area of the electronic shutter is driven by a drive pulse, and by adjusting the duty cycle of this drive pulse independently for each color, the color of the copied image can be adjusted.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

〔Example〕

In FIG. 1 schematically showing a silver halide photocopier, a color original 1 is set on a transparent stage 10 and illuminated with slit light from a lamp unit 2. As shown in FIG. This lamp unit 2 is composed of a lamp 3, a reflector 4, and a mirror 5, and when copying a color original 1, a first
Move at a constant speed in the direction of the arrow from the position shown in the figure.

The reflected light from the color original l is reflected laterally by the mirror 5 and then enters the mirror unit 7. This mirror unit 7 includes mirrors 8 and 9, and moves in synchronization with the lamp unit 2 and at half the speed of the lens unit 2.
Keep the object point distance of 3 constant.

The light reflected by the mirror 9 enters a color photosensitive material 14, such as a color autopositive photosensitive material (hereinafter referred to as color positive photosensitive material), via a lens unit 13. The lens unit 13 includes a front group 15 and a rear group 16, and a PLZT 17 is arranged between them. This PLZT17
A color filter 18 is bonded or deposited on one side of the lens, and the PLZT 17 is arranged so that the color filter 18 is located at the pupil position of the lens system.

As shown in FIG. 2, the PLZT element 17 includes a PLZT element 19 made of a lanthanum-doped lead zirconium titanate ceramic material, and polarizers 20 disposed on both sides of the PLZT element 19 so that their alignment axes are perpendicular to each other. It consists of 21. Note that the deflection axes of the deflectors 20 and 21 are indicated by arrows. This PLZT element 19 has, for example, three sets of transparent electrodes 19a and 19b divided into three rectangular shapes on both sides thereof.
.

19c is formed. This 3All transparent electrode 19
When a voltage is applied to a-19c, the deflection direction of the incident light is rotated in each portion, so that the transmittance of the incident light is adjusted by the deflection action with the polarizers 20 and 21. In addition,
If the deflection axes of the deflectors 20 and 21 are aligned, a normally open type electronic shutter can be obtained.

The color filter 18 is a rectangular yellow filter 18a, as shown in FIGS. 3 and 4.

It consists of a magenta filter 18b and a cyan filter 18c, and three transparent electrodes 19a to 19a shown in FIG.
19c. Since this color filter 18 is placed close to the pupil position of the lens system, the slit light will not be partially colored. In addition,
A red filter, a green filter, and a blue filter may be used instead of the yellow filter, magenta filter, and cyan filter.

At the exposure position, a slit mask 23 for slit exposure of the color positive photosensitive material 14 and a pressure plate 24 for holding the color positive photosensitive material 14 flat are arranged. Rollers 25 and 26 are arranged. A color positive photosensitive material 14 in the form of a roll is stored in the magazine 27, and a pull-out roller 28
It is pulled out to a certain length by a cutter 29, and then cut by a cutter 29.

After the leading edge of the cut color positive photosensitive material 14 is detected by the sensor 30, it is conveyed a certain distance, and is temporarily stopped at a position where the leading edge is nipped by the exposure conveying roller 25. When the scanning of the color original 1 is started in response to the exposure start signal, the exposure transport rollers 25 and 2 are moved in synchronization with this.
6 rotates and transports the color positive photosensitive material 14. The color positive photosensitive material 14 is exposed to slit light during transportation, and then sent to a photo development processing section 31, where it is developed and then transferred to a tray 32.
is discharged.

An operation panel 34 is provided on the main body of the copying machine (not shown). This operation panel 34 includes a color key 35 for performing color adjustment and a copy key 36, and sends input data to the controller 3. The color key 35 includes three types of color keys, yellow magenta and cyan, and each color key is composed of a plurality of keys to change the exposure amount in steps.

The controller 3 sends signals to the pulse signal generator 39 to control the duty cycles of the three types of pulses. This pulse signal generator 39, pulse oscillation circuit 4
0, and a duty cycle adjustment circuit 41 that adjusts the duty cycles of three types of pulses. This duty cycle adjustment circuit 41 is configured, for example, by a one-shot multi-by-break circuit with a variable pulse width, or a delay circuit with a variable delay time, and an AND operation that calculates the logical product of this output and a pulse that is not delayed.
It consists of a circuit.

The driver 42 is supplied with power from a constant voltage power supply 43,
Power is amplified in accordance with the pulses of each color output from the pulse signal generator 39, and the three types of drive pulses obtained are sent to the transparent wires 19a to 19c of the PLZT element 19, respectively.

FIG. 5 shows intermittent exposure using pulsed light.

In this intermittent exposure, an arbitrary point on the color positive sensitive material 14 receives 1tHt of exposure while passing through the slit mask 25.
(i is yellow, magenta.

(representing any one of cyan) is expressed by the following formula.

Ht = E x 'r x (Tit/T
2) = E X Tl, X N ・−=・(
1) Here, each symbol is as follows.

E: Color positive photosensitive material 1 through PLZT17
Illuminance T of the pulsed light incident on 4: Time required for an arbitrary point of the color positive sensitive material 14 to pass through the slit mask 25 Tl: Width T2 of the pulsed light: Period Tl/T2: Duty cycle N: Time required for the slit mask 25 to pass through the slit mask 25 Since the number of pulses received during passing, the exposure amount H, depends on the duty cycle, color correction can be performed by adjusting this duty cycle. Note that in intermittent exposure, reciprocity law failure may occur, so it is necessary to adjust the duty cycle within a range in which this reciprocity law failure does not occur.

Next, the operation of the embodiment shown in FIG. 1 will be explained. When the previous copying is completed, the pull-out roller 28 rotates to pull out the color positive photosensitive material 14 from the magazine 27. When this color positive photosensitive material 14 is pulled out for a certain length, a cutter 29 is operated to cut it into sheets. After the leading edge of the cut color positive photosensitive material 14 is detected by the sensor 30, it is conveyed a certain distance, and the leading edge is transferred to the conveying roller 25.
It stops at the position where one nail is nailed.

When copying, when the color original 1 is set on the stage 10 and the copy key 36 on the operation panel 34 is operated, the lamp unit 2 moves at a constant speed in the direction of the arrow, and the mirror unit 7 moves relative to the lamp unit 2. 1/2
The color original 1 is illuminated by the slit. After a predetermined time delay from the start of the scan, the exposure conveyance rollers 25 and 26 rotate to convey the sheet-like color positive photosensitive material 14 at a speed synchronized with the lamp unit 2.

On the other hand, the controller 38 sends a control command to the duty cycle adjustment circuit 41 to set the standard duty cycle to, for example, 50%. The pulses output from the pulse oscillation circuit 40 are sent to a duty cycle adjustment circuit 41, where the duty cycle is converted to, for example, 50%. The driver 42 includes the duty cycle adjustment circuit 4
A drive pulse is generated by amplifying the three types of pulses output from 1. This driving pulse, as shown in FIG.
Since the light is supplied to each of the transparent electrodes 19a to 19C of the PLZT element 19, each area of the PLZTI 7 divided into three parts alternately transmits and blocks the incident light.

The reflected light from the color original 1 is reflected by mirrors 5 , 8 and 9 and enters the lens unit 13 . This lens unit 13 has a PLZT divided into three areas.
17 and yellow filter 1 corresponding to each area.
8a, magenta filter 18b, cyan filter 18
c is provided, the light is converted into pulsed light of yellow, magenta, and cyan light. This slit-shaped pulsed light passes through the slit mask 25 and is incident on the color positive sensitive material 14 that is being transported, and records a positive color image thereon.

777': When the l-nit 2 moves to the predetermined position and the slit illumination of the color original 1 is completed, the lamp unit 2 and the mirror unit 7 return to the positions shown in FIG. 1, and the operation of the PLZT 17 is stopped. The exposure ends. After exposure, the color positive photosensitive material 14 is sent to a photographic development processing section 31, where it is subjected to color development, bleach-fixing, washing, and drying processes, and then discharged onto a tray 32. Through this photographic development process, a copy image of the color original 1 is formed as a positive image on the color positive sensitive material 11.

In the standard state described above, the duty cycle of the drive pulse is 50% for each color, so the exposure amounts for yellow, magenta, and cyan are the same. If the color balance of the copied image is not good in this standard state, or if you want to intentionally change the color balance, you can operate the color key 35. For example, when you operate the yellow key, the A signal is input to controller 38. As shown in FIG. 6, this controller 38 changes the duty cycle of the yellow drive pulse according to the number of yellow keys.

As a result, the yellow driving pulse has a pulse width of t.
1 (t 1 < TI), the exposure amount of yellow decreases.

Although the above embodiment uses a color filter divided into three rectangular shapes, a color filter 45 divided into three circular shapes may be used instead, as shown in FIG. In this case,
The transparent electrodes 19a to 19c are also formed into three circular parts.

In the above explanation, color correction is performed manually, but
This can also be done automatically. In this case, a mirror shutter is placed in front of the slit mask 25, and the color original is pre-scanned before copying, and during this pre-scanning, the reflected light of the color original 1 is extracted through the mirror shutter and three-color light is measured. Then, according to the photometry results, the duty cycle is set eight times for each color, and the color balance is automatically corrected.

Furthermore, instead of moving the lamp unit and the mirror unit, a structure may be used in which the reflective original is moved and exposed to slit light. Furthermore, although the color positive photosensitive material has been explained, other silver salt photosensitive materials such as diffusion transfer photosensitive materials,
The present invention can also be applied to color photographic paper, thermal transfer photosensitive materials, and the like.

〔Effect of the invention〕

As explained in detail above, according to the present invention, an electronic shutter divided into three areas is used, a color filter is arranged in each area, and the duty cycle of the drive pulse for driving each of these areas is adjusted. Since each color can be changed independently, color adjustments can be made easily. Furthermore, since the plurality of color filters do not overlap, 4 degrees of incorrect absorption will not occur.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing a silver salt photographic color copying machine embodying the present invention. FIG. 2 is an exploded view showing the configuration of PLZT. FIG. 3 is a perspective view schematically showing the lens unit. FIG. 4 is a front view of an embodiment using a color filter divided into three rectangular shapes. FIG. 5 is a waveform diagram showing drive pulses applied to PLZT. FIG. 6 is a waveform diagram showing a state in which the duty cycle of the yellow drive pulse is changed. FIG. 7 is a front view showing an embodiment using a color filter divided into three circular parts. 18... Color filter 19... PLZT elements 19a to 19c... Transparent electrode 20.21... Deflector 35... Color key 45... Color filter. 1...Color original 13...Lens unit 14...Color positive photosensitive material 17...PLZT

Claims (3)

[Claims] (1) In a copying machine in which reflected light from a color document illuminated by a slit is formed into an image on a color photosensitive material through an exposure optical system, the exposure optical system is located approximately at the pupil position, and is independently illuminated. An electronic shutter with three areas with varying transmittance, three types of color filters arranged corresponding to each area of the electronic shutter, and a pulse generated to drive each area of the electronic shutter. pulse generating means for
A color adjustment device characterized by comprising means for changing the duty cycle of this pulse for each color. (2) The color adjustment device according to claim 1, wherein the electronic shutter is made of PLZT. (3) The color adjustment device according to claim 2, wherein the three types of color filters are a cyan filter, a magenta filter, and a yellow filter.