JPH0211354A - Color data separation apparatus of copier - Google Patents

Abstract

PURPOSE:To separate the color image of a manuscript without being affected by a change in the quantity of light by controlling the reflected light incident to an image reading means while monitoring a change in the exposure quantity of light. CONSTITUTION:A controller part 7 analyzes the copy mode data from an console 8 to collectively control a copy sequence according to a control program. The controller part 7 is also used as a quantity-of-light control means and, when the quantity of light of a manuscript irradiation lamp 2 is varied by the setting of density from the console 8 or the variation of a power supply, said controller part 7 controls the throttling state of an image forming lens 32 on the basis of the quantity of the light, which is transmitted through each color filter on the basis of the quantity of light of said lamp 2 to be incident to an image reading part 5a, by controlling the driving of an actuator M2 on the basis of the variation of the power supply detected by a quantity-of-light controller 71 by a CPU 65. Even when the exposure quantity of light to the manuscript is varied, the quantity of transmitted and incident light can be always controlled constant and the separation mistake of a color image region due to an image reading means based on the variation in the quantity of light can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copying apparatus that separates an image area of a specified color from reflected light exposed to a document and forms an image in the specified color. In particular, the present invention relates to a color information separation device for a copying machine that separates color information while recognizing the wavelength characteristics of the colors to be separated.

[Conventional technology]

Conventionally, in this type of device, such as an analog copying machine, a latent image is erased by emitting light from, for example, an LED array onto an area specified by an erase area specifying means provided in an operation unit, such as a digitizer or numerical input. A model equipped with an eraser function has been commercialized.

Furthermore, in a digital copying machine, such as a laser beam printer, image information read from a reader is temporarily buffered in memory, and when masking processing is specified for area data specified from the operation unit, A model has also been commercialized that is configured to perform image processing that converts the image information stored at the address corresponding to the area data into white image information, and to easily perform cropping copying by erasing the specified image. There is.

By the way, recent image processing apparatuses are configured so that a plurality of developing units can be stored in a replaceable manner, and when performing the above-mentioned trimming copy, it is possible to perform trimming copying in a desired copy color, There is an increasing demand for obtaining a well-designed or impressive copied image by multiple-transferring trimmed images of different colors onto a single transfer sheet.

(Problem to be Solved by the Invention) However, in order to perform color separation in an analog copying device such as the one described above, usually a color separation filter is used to erase the corresponding color areas on the document, and multiple transfers are performed multiple times. Although it is possible to obtain a desired multiple color image through the process, copying machines are usually provided with a density adjustment setting section and are configured to allow the density of the copied image to be set automatically or manually. .

For this reason, when such a density setting is applied, the amount of light used to expose the document is often controlled, and with a color separation filter that has a constant amount of transmitted light as the amount of light changes, the wavelength of the reflected light changes. Because the peak characteristics change,
Due to subtle differences in color balance between the color images on the original, there have been problems such as the color image on the original being misidentified and the color images on the original being unable to be accurately separated.

If we try to solve this kind of problem using color separation filters, the number of color separation filters corresponding to the characteristics will increase.
This causes problems such as complicating the hardware configuration and detection circuit, and significantly increasing costs.

This invention was made in order to solve the above-mentioned problems, and by adjusting the amount of reflected light that enters the image reading means while monitoring the fluctuations in the amount of exposure light when scanning the original, it is possible to adjust the amount of light reflected from the image reading means. An object of the present invention is to obtain a color information separation device for a copying machine that can separate color images of a document without being separated.

[Means for Solving the Problems] A color information separation device for a copying apparatus according to the present invention includes a color information separation device for a copying machine that separates light from an original scanning unit into an image reading means via a color separation filter means based on a variation in the amount of light exposed to a document. A light amount adjustment means is provided to adjust the amount of light emitted.

[Effect]

In this invention, when the amount of light exposed to the document from the document scanning unit changes, for example, when the amount of exposure light changes due to density settings, the light amount adjustment means transmits the light to the image reading means via the color separation filter means. Adjust the light intensity.

[Embodiment] FIG. 1 is a sectional view showing an example of a color information separating device of a copying machine according to an embodiment of the present invention. The placed original is exposed by the original irradiation lamp 2, and the reflected light is imaged on the photosensitive drum 10 via the scanning mirrors 38 to 3d and the imaging lens 4.

5 is a color separation unit, which includes a color separation filter and, for example, a CC
It is composed of an image reading section 5a (described later), which is composed of an image sensor such as D, etc., and separates color images of the original.

Reference numeral 6 denotes a hue detection unit, which detects the hue state on the original, and is composed of an image sensor such as a CCD and a color filter, and as described later, the hue detection unit stores the hue level of the color image on the original in advance. Detection is done by comparing with a reference value.

Reference numeral 7 denotes a controller section that analyzes the copy mode information from the operation section 8 and performs overall control of the copy sequence according to a control program stored in a ROM (not shown). Note that the controller section 7 also serves as a light amount adjustment means according to the invention, and when the light amount of the document irradiation lamp 2 fluctuates due to density settings from the operation section 8 or power fluctuations, image reading is performed based on the light amount. The amount of light that passes through each color filter and enters the section 5a is adjusted, for example, by adjusting the aperture position of an imaging lens, etc., so that a constant amount of reflected light is always received, thereby eliminating color separation errors caused by each color filter.

The operation unit 8 includes numeric keys 8a, ? An IA degree setting lever 8b, a sheet number display 8c, and a message display 8d are provided.

Reference numeral 9 denotes an eraser composed of a semiconductor laser or the like, which irradiates the photosensitive drum 10 with an erase beam in response to an erase signal from the controller section 7 to erase a part of the formed electrostatic latent image.

A cleaner section 11 collects toner remaining on the photosensitive drum 10 and cleans the surface of the photosensitive drum 10.

Reference numeral 12 denotes a pre-discharge lamp, which is used to remove electricity from the photosensitive drum 1 in preparation for image formation.
Eliminates the zero charge. A primary charger 13 uniformly charges the surface potential of the photosensitive drum 10. Reference numeral 14 denotes a replaceable first developing unit, which contains, for example, blue toner. Reference numeral 15 denotes a replaceable second developing unit, which contains, for example, red toner. 16 is a paper feed section, and paper feed roller 1
7a.

The transfer material is fed to the position where the registration rollers 18 are arranged by driving the rollers 17b.

A transfer charger 19 transfers the developed toner image onto the transfer material fed by the drive of the registration rollers 18.

A separation charger 20 separates the transfer material adsorbed onto the photosensitive drum 10 from the photosensitive drum 10.

A conveyor belt 21 conveys the transfer material that has undergone the transfer process to the fixing roller 22 . A flapper 23 switches the conveyance direction of the transfer material after the fixing process to the paper discharge tray 25 or the intermediate tray 27. A paper discharge roller 24 discharges the transfer material after the transfer process has been completed.

Feed rollers 26a to 26c convey the transfer material guided by the drive of the flapper 23 to the intermediate tray 27, and also feed it again in the direction of the registration rollers 26d. S
S is an image tip sensor.

1 r IL2 + 1211 + β12 indicates the area of each color. SS1 and 5SII indicate color separation positions.

FIG. 2 is a schematic diagram illustrating the arrangement of the imaging system shown in FIG. 1, and the same components as in FIG. 1 are given the same reference numerals.

In this figure, reference numeral 31 denotes a color separation filter, which is composed of, for example, a red filter, a blue filter, a green filter, etc., and is rotated by an actuator, which will be described later, so that a desired color filter is positioned on the optical path of the imaging lens 32. .

Numerals 34a and 34b are hue detection sensor sections, which are composed of a detection element and a color filter.

FIG. 3 is an enlarged perspective view of essential parts for explaining the configuration of the eraser 9 shown in FIG. 1 and its control system, and the same parts as in FIG. 1 are given the same reference numerals.

In this figure, 41 is a manuscript, for example, the letter P (red)
The image 41a is placed on the document table glass 1 with the image surface facing downward. 42 is an image area processing unit;
The color of the color separation filter 31 is switched and set based on the copy color designation specified from the switch box 43 provided in the operation unit 8, and in this state, image area information detected from the exposed original g441 is divided into a predetermined scanning area ( (from the exposure position scanned by the scanning mirror 3d to the exposure position of the laser beam scanned from the eraser 9), and at the timing when the photosensitive drum 10 rotating at a constant speed reaches the exposure position of the laser beam scanned from the eraser 9. Driver circuit 44
The photosensitive drum 10 is irradiated with an erase beam based on the image area information stored in the image area processing section 42, thereby erasing the latent image formed on the photosensitive drum 10.

Next, the color image recognition erase processing operation according to the present invention will be explained with reference to FIG.

FIG. 4 is a schematic diagram illustrating the color image recognition erase processing operation according to the present invention.
It is composed of 1R, a black image 51B, etc.

Reference numeral 52 denotes a multiple first side transfer image sheet, and when a copy color is specified, for example, red, only the black image 52B is transferred, and the shaded area becomes the erase area. That is, the eraser 9 functions until the image area is detected and the red image 5 is
1R is erased. Reference numeral 53 denotes a multiple second side transfer image sheet, and when a copy color, for example, red, is specified for the multiple first side transfer image sheet 52, the erase process is performed exclusively on the first side. That is, manuscript 51
The upper black image 51B is erased (the shaded area in the figure), and only the red image 53R is transferred.

The original 51 is placed at a predetermined position on the original platen glass 1 shown in FIG. 1, and the copy color is specified using the switch box 43. For example, if red is specified by this copy color specification,
The second developing unit 15 is selected, and the electrostatic latent image formed on the photosensitive drum 1o can be developed in red.

On the other hand, the image area processing unit 42 switches the color separation filter 31 to red based on the copy designation specified from the switch box 43 and sets the multiple transfer, and in this state, the first multiple exposure of the original g451 starts. When it is done,
The red image 51R on the original 51 is removed by the color separation filter 31, and the reflected light in the sub-scanning direction is sequentially transmitted to the image reading unit 5.
The image area processing unit 42 outputs erase information to the driver circuit 44 until the leading edge of the black image 51B area in the document 51 is captured, and when the leading edge of the black image 51B area is captured, image area processing begins. An off command is output from the section 42 to the driver circuit 44, the black image 52B is transferred to the multiple first side transfer image sheet 52, a known electrophotographic process is performed, and the conveyance is controlled by the flapper 23 in the direction of the intermediate tray 27. , and is fed to the position where the registration roller 26d is disposed, and then conveyed to the position of the registration roller 18 based on a drive command from the image area processing section 42, and once stopped.

In this state, exposure of the multiplexed second side of the document starts, and black image area information in the document 51 is accumulated in an internal memory (not shown) of the image area processing section 42 in parallel with the exposure of the document. Based on the black image area information stored in the internal memory, the image area processing unit 42 outputs erase information to the driver circuit 44, and the end of the image area stored in the internal memory of the image area processing unit 42 is When the erase beam irradiation position of the photosensitive drum 10 to be scanned is reached,
The photosensitive drum 10 is irradiated with an erase beam (laser beam) to erase the electrostatic latent image corresponding to the formed black image 51B. Therefore, only an electrostatic latent image for the red image is formed on the photosensitive drum 10 by the reflected light of the red image 51R that is not irradiated with the erase beam, and only this electrostatic latent image is transferred to the second developing unit containing the red developer. Developed in 15,
The multiplexed second image shown in FIG.
A surface transfer image sheet 53 is obtained, and only the red image 53R is transferred and fixed, and the diagonally shaded area is output with the erased state. As a result, a black image 52B and a red image are formed on the multiplex second surface transfer image sheet 53. A 53R multiple cropped image is formed.

The image area stored in the internal memory of the image area processing section 42 is image information from the exposure position scanned by the scanning mirror 3d to the exposure position of the laser beam scanned from the eraser 9.

Next, the color image recognition erase control operation according to the present invention will be explained with reference to FIGS. 5 and 6.

FIG. 5 is a flowchart illustrating the image forming control operation procedure according to the present invention. Note that (1) to (6) indicate each step.

Specify the copy color of the original using the switch box 43 provided in the operation unit 8, and if red is specified, for example, input the light separation designation to the image area processing unit 42 (1)
. Next, wait for the copy key to be pressed 2)
When the copy key is pressed, the image area processing unit 4
2) the color separation filter 31 is switched to the red filter and set 3), the image area processing section 42 drives the eraser 9 until the image reading section 5a detects the image area, and erases the area outside the image area (red image area). Then, the electrostatic latent image corresponding to the black image 51B formed on the photosensitive drum 10 is developed to black, thereby obtaining an image on the first side of the multiplex (4).

Next, wait for the first side copying to finish (5), and when the multiplexed first side copying is finished, erase the image area (black image area) detected by the image reading section 5a and erase the formed electrostatic latent image. Develop with the red toner contained in the second developing unit 15 to form multiple trimmed images of a black image 52B and a red image 53R on the multiple second side transfer image sheet 53. 6) End the control.

FIG. 6 is a flowchart illustrating a drive control operation procedure for the eraser 9 shown in FIG. In addition, (1) to (
9) shows each step.

Original irradiation lamp 2. The optical system composed of the scanning mirrors 38 to 3d is advanced (1), and exposure of the original 51 placed on the original platen glass 1 is started. Image area processing unit 4
2) waits for the optical system to reach the document exposure start position, that is, the image tip; 2), that is, the image tip signal that is output when the image tip sensor SS detects a member of the optical scanning system is output. When the optical system reaches the image tip, the image reading section 5a starts image area detection in parallel with the exposure scanning of the optical system, and the optical system detects, for example, the black image 51 of the original 51.
When reaching B, create one line of image area data 3) and judge whether it is erased outside the image area 4)
) If YES, the image area processing unit 42 creates erase data outside the image area 5), and stores the created erase data outside the image area in the internal memory (6).

Thereby, the image exposure position and the erase position are synchronized. Next, the image area processing unit 42 drives the eraser 9 until the image area detected in the internal memory reaches the erase beam irradiation position from the eraser 9, corresponding to the red image 51R formed on the photosensitive drum 10. The red image 51R of the original 51 is erased from among the electrostatic latent images formed on the photosensitive drum 10 (7).

Next, determine the end of the erase area (image end).
), if YES, end the control, if No, step (
Return to 3).

On the other hand, if the determination in step (4) is NO, the image area processing unit 42 creates erase data within the image area.9)
, returns to step (6), and irradiates the erase beam to a position corresponding to the black image 51B formed on the photosensitive drum 10 based on the erase data in the image area stored in the internal memory, and erases the image formed on the photosensitive drum 10. Among the electrostatic latent images, the black image 51B of the original 51 is erased.

Note that the image end is determined by a timer that is driven for a certain period of time after the optical system is reversed.

Next, the relative relationship between the color separation filter 31 shown in FIG. 1 and the image reading section 5a will be explained with reference to FIGS. 7 and 8.

FIG. 7 is a schematic diagram showing the relative arrangement relationship between the color separation filter 31 and the image reading section 5a shown in FIG.
Components that are the same as those in the figures are given the same reference numerals.

In this figure, Ml and M2 are actuators composed of, for example, stepping motors, and actuator M
1 switches and positions the color separation filter 31 according to a drive signal from the controller section 7, and operates an actuator M.
2 adjusts the aperture of the imaging lens 32 in accordance with a drive signal from the controller section 7 .

FIG. 8 is a characteristic diagram illustrating the incident light wavelength characteristics for each color filter of the color separation filter 31 shown in FIG. (μm).

(a) shows the sensitivity characteristics, ■ shows the sensitivity characteristics of the image reading section 5a, II shows the characteristics of the document irradiation lamp 2, and I
II indicates the sensitivity characteristic of the blue filter, and ■ indicates the sensitivity characteristic of the red filter.

(b) shows the sensitivity peak characteristics of the red filter, and shows the case where the peak occurs at, for example, 630 μm.

(C) shows the sensitivity peak characteristics of the blue filter, and shows the case where the peak occurs at, for example, 450 μm.

As can be seen from these figures, when the color filter of the color separation filter 31 is set to blue, the peak value of the image reading section 5a is approximately 450 μm, and when the color filter of the color separation filter 31 is set to red. In this case, the peak value of the image reading section 5a is 630 μm.

However, as mentioned above, if the color image of the original has a slight change in hue from the above peak value (to the extent that it looks almost the same to the naked eye), it may become impossible to separate the specified color images. .

Therefore, by minutely detecting the hue state of the document using the circuits shown in FIGS. 9 and 10, the optimal color filter for the specified area is selected and set, and the color recognition threshold level ( (described later) is variably set based on the hue state to be detected.

The configuration and operation thereof will be described in detail below with reference to FIGS. 9 and 10.

FIG. 9 is a circuit block diagram illustrating the configuration of the hue detection section 6 shown in FIG. 1, and the same components as in FIG. 1 are given the same reference numerals.

In this figure, 61a is a blue filter, and this blue filter 61a and a sensor 62a composed of a charge-coupled device such as a CCD constitute a hue detection sensor section 34a. A wavelength component corresponding to the blue filter characteristics is detected. 63a is an amplifier;
The output of sensor 82a is amplified. 64a is an A/D converter which A/D converts the output of the sensor 62a and outputs detection level data to the CPU 65. The CPU 85 compares this detection level data with pre-stored reference value data and recognizes the color and hue state of the reflected light.

61b is a red filter, and this red filter 61b,
A sensor 62 composed of a charge-coupled device such as a CCD, for example.
b constitutes a hue detection sensor section 34b, which detects a wavelength component of the reflected light that corresponds to the red filter characteristics shown in FIG. 8.

An amplifier 63b amplifies the output of the sensor 62b. 6
4b is an A/D converter which A/D converts the output of the sensor 62b and outputs detection level data to the CPU 65. C.P.
U65 compares this detection level data with hue state determination reference data stored in advance, and recognizes the color and hue state of the reflected light.

Note that the hue detection sensor units 34a and 34b are arranged on a straight line parallel to the main scanning direction of the optical scanning system, and one scan scans, for example, a blue or red image among color images on a document, which will be described later. It is now possible to perform simultaneous detection during scanning.

FIG. 10 is a schematic diagram for explaining the original image hue detection operation by the hue detection section 6 shown in FIG. 9, and the same parts as in FIG. 9 are given the same reference numerals.

In this figure, 66 is a document placed on the document table glass 1 shown in FIG.
This shows the case where . PO is a color separation designated position, for example, which is inputted manually from the operation unit 8 or the like.

Next, with reference to FIGS. 11(a) and 11(b), the hue state detection and color filter selection setting operations by the hue detection section 6 will be described.

FIG. 11(a) is a flowchart illustrating an example of the hue state detection and color filter selection setting control procedure by the hue detection section 6 according to the present invention.

Note that (1) to (18) indicate each step, and each step is stored in the ROM of the controller section 7 shown in FIG. In addition, the ROM of the controller section 7 has an 11th
Hue state determination reference data a to h shown in FIG. 3(b) are stored in advance.

When the optical scanning system starts scanning the specified area 11, the CPU 65 reads the blue detection level data X output from the A/D converter 64a (1), and the detection level data X matches the hue state determination reference data a. 2), YE
If S, the threshold level to be described later for processing the output from the image reading section 5a shown in FIG.
3) Furthermore, a signal to set the filter color of the color separation filter 31 to blue is sent to the actuator M.
1 and set it to the blue filter (4).

Next, the detected color is displayed as "blue" on the message display 8d (5), and the process is terminated.

On the other hand, if the determination in step (2) is NO, it is determined whether the blue detection level data X is a value between the hue state determination reference data b and the hue state determination reference data C.e)
If YES, the threshold level to be described later for processing the output from the image reading section 5a shown in FIG. 1 is set to "2" (7), and the process returns to step (4).

On the other hand, if the determination in step (2) is No, it is determined whether the detection level data X is a value between the hue state determination reference data C and the hue state determination reference data d8) Y.
In the case of ES, the threshold level described later for processing the output from the image reading section 5a shown in FIG.
3" (9) and return to step (4).

On the other hand, if the judgment in step (8) is NO, the CPU 6
5 reads the red detection level data y from the A/D converter 64a (10), and judges whether the detection level data y is a value between the hue state determination reference data e and the hue state determination reference data f. 11) If YES, set the threshold level (described later) for processing the output from the image reading section 5a shown in FIG.
), and further sends a signal to set the filter color of the color separation filter 31 to red to the actuator M1 to set the filter color to red (13).

Next, the process returns to step (5), and the detected color is displayed as "red" on the message display 8d, and the process ends.

On the other hand, if the judgment in step (11) is No, it is necessary to judge whether the red detection level data y is a value between the hue state judgment reference data f and the hue state judgment reference data g.
4) If YES, the image reading section 5a shown in FIG.
15), and return to step (13).

On the other hand, if the judgment in step (14) is NO, it is necessary to judge whether the red detection level data y is a value between the hue state judgment reference data g and the hue state judgment reference data h.
6), if YES, the image reading section 5a shown in FIG.
17), and return to step (13).

On the other hand, if the determination in step (16) is No, the message display 8d displays that the desired filter color is not available, that is, color separation is not possible (18), and the process ends. As a result, even if the hue of the blue image 88B or the red image 66R on the original 66 is different from the wavelength characteristics of each color filter of the color separation filter 31, the image reading unit 5a can detect the judgment level (described later) for determining the image recognition level. By switching and connecting the threshold level that determines the threshold level of the comparator), it is possible to separate a blue image and a red image with hues that change from the wavelength characteristics of the blue image 66B or the red image 66R.

However, the above-mentioned control is based on the assumption that there is no variation in light intensity, and in actual operation, the density may be varied by the density setting lever 8b in the operation section 8, The light intensity of the document irradiation lamp 2 varies as described above due to the density setting, and there is a possibility that a situation may occur in which color separation cannot be performed accurately by the image reading section 5a.

Therefore, by using a circuit as shown in FIG. 12, the gain of the amplifier that amplifies the output of the image reading section 5a or the judgment level that determines the image recognition level is varied according to the setting state of the density setting lever 8b. Corrects the effects of light intensity fluctuations.

The operation will be described below with reference to the circuit shown in FIG.

FIG. 12 is a sensor output correction processing circuit diagram of the image reading section 5a, and the same components as in FIG. 1 are given the same reference numerals.

In this figure, 71 is a light amount control circuit that controls the current supplied to the driver DR that turns on the document irradiation lamp 2 according to the density setting value detected by the controller section 7, and adjusts the amount of light emitted by the document irradiation lamp 2. . Further, the controller unit 7 controls the light amount of the original irradiation lamp 2 to be constant even if the voltage applied to the original irradiation lamp 2 fluctuates.

TRI and TR2 are transistors that are turned on and off by the correction signal DO3 and signal output O5 output from the image reading section 5a, and output potentials determined by the resistors R1 to R4 to the operational amplifier oP1.

VRI is a variable resistor, and its resistance value is determined by a control signal from the CPU 65 in accordance with the setting state of the concentration setting lever 8b.

SWI is a switch that switches and connects the resistors R5 to R7 to vary the differential amplification factor of the operational amplifier oP1. OP2
is an operational amplifier, and the operational amplifier oP1 is connected to the non-inverting input terminal.
The output of is input manually, and a potential determined by the division between resistors R8 to R11 and variable resistor VR2 is applied to the inverting terminal.

The resistance value of the variable resistor VR2 is determined by the concentration setting lever 8.
Following the setting state of b, its resistance value is determined by a control signal from the CPU 65, and the threshold level of the operational amplifier OP2 serving as a comparator is variably set. That is, the threshold level of the operational amplifier OP2 is varied based on the variation in the amount of light, thereby preventing erroneous color separation of the color separation filter 31 based on the variation in the amount of light.

When the correction signal DOS and the signal output O5 are output from the image reading section 5a, the difference between them is amplified by the operational amplifier 0P1. This cancels out the offset bias and reset noise of the image reading section 5a.

At this time, the value of the concentration setting lever 8b is set by the CPU using the operation unit 8.
When the resistance value of the variable resistor VRI is set to increase the light intensity of the document irradiation lamp 2 using the density setting lever 8b, the resistance value of the variable resistor VRI is decreased and the resistance value of the operational amplifier OPI is set. Decrease the gain.

On the other hand, the value of the concentration setting lever 8b is set by the CPU 6 using the operation unit 8.
When the resistance value of the variable resistor VRI is set to decrease the light intensity of the document irradiation lamp 2 using the density setting lever 8b, for example, the resistance value of the variable resistor VRI is increased and the resistance value of the operational amplifier OP1 is increased. Increase the gain. In parallel with this operation, the CPU 65 switches a switching control signal to selectively connect any one of the resistors R5 to R7 for fixing the gain of the operational amplifier OPI based on the filter color of the color separation filter 31. Output to SW1.

As a result, even if the light intensity of the original irradiation lamp 2 changes, the output level of the operational amplifier OPI remains constant without affecting the filter color of the color separation filter 31 (offsetting the difference in transmittance of the filter color of the color separation filter 31). becomes.

Further, the feedback resistance value of the operational amplifier OPI is fixed (the gain is constant), and the resistance value that determines the threshold of the operational amplifier OP2 that binarizes the output of the image reading section 5a is varied based on the setting state of the density setting lever 8b. In addition, the resistance value may be determined to determine the threshold of the operational amplifier OP2 that binarizes the output of the image reading section 5a using the color filter of the color separation filter 31. That is, when the density is varied based on the setting state of the density setting lever 8b as in the former case, especially when the light amount of the document irradiation lamp 2 is set to increase by operating the density setting lever 8b,
Increase the division value of variable resistor VR2, and use operational amplifier OP2.
Increase the threshold (binarization level) input to the inverting terminal of .

On the other hand, when the light intensity of the document irradiation lamp 2 is set to decrease by operating the density setting lever 8b, the division value of the variable resistor VR2 is lowered, and the threshold (binary value) manually input to the inverting terminal of the operational amplifier OP2 is level).

Then, the CPU 65 switches and connects the switch SW2 according to the filter color of the color separation filter 31 to be selected, thereby suppressing erroneous color separation due to variations in light amount.

Furthermore, in order for the above-mentioned control to function effectively, it is assumed that power fluctuations have converged within a certain allowable range; however, if there are fluctuations in the input power, even the above control may cause light intensity fluctuations. This may cause the image reading section 5a to be unable to perform color separation normally.

Therefore, when power fluctuation occurs, the image reading section 5a
The amount of light incident on the CPU 6 determines the aperture state of the imaging lens 32.
5 is adjusted by controlling the drive of the actuator M2 shown in FIG. 7 based on the power fluctuation detected by the light amount control device 71.

The adjustment process will be described below with reference to FIG. 13.

FIG. 13 is a flowchart illustrating an example of a light amount fluctuation adjustment procedure according to the present invention. In addition, (1) to (13)
indicates each step.

First, the CPU 65 determines whether the imaging lens 32 is at a preset home position (initial position) (1) If no, drives the actuator M1 (2), so that the imaging lens 32 is at a preset home position (initial position). position to the home position.

On the other hand, if the determination in step (1) is YES, it is determined whether the filter of the color separation filter 31 is a blue filter.3) If YES, the actuator M2 is driven with preset pulse data N,4) The aperture position of the imaging lens 32 is determined. Then, the amount of light incident on the image reading section 5a is determined. Note that this amount of light is determined in advance based on the amount of light transmitted through each color filter of the color separation filter 31.

On the other hand, if the determination in step (3) is No, actuator M2 is driven with preset pulse data N2 (5), and the process proceeds to step (6).

Next, in order to cope with the light amount fluctuation caused by the setting of the density setting lever 8b, it is determined whether the set value of the density setting lever 8b is Fl (8), and if YES, the actuator M2 is driven with the preset pulse data N. 7)
, the aperture position of the imaging lens 32 is set to a predetermined position, and the process is completed.

On the other hand, if the judgment in step (6) is No, it is necessary to judge whether the setting value of the density setting lever 8b is F28)
If YES, actuator M2 is driven with preset pulse data N4 (9), and the process ends.

On the other hand, if the determination in step (8) is No, it is determined whether the set value of the density setting lever 8b is F3 (10),
If YES, actuator M2 is driven with preset pulse data N5 (11), and the process ends.

On the other hand, in step (10), it is determined whether or not the set value of the density setting lever 8b is FN by repeating the above processing sequentially (12), and if YES, the actuator M2 is driven with the preset pulse data NN (13). ),
Finish the process.

Next, the one-scan color separation filter switching setting operation according to the present invention will be explained with reference to FIG.

FIG. 14 is a flowchart illustrating an example of a one-scan color separation filter switching setting control procedure according to the present invention. Note that (1) to (10) indicate each step.

Note that before executing this process, the area to be separated by each color filter of the color separation filter 31 is set using the operation unit 8, for example, in the 10th area.
As shown in the figure, the color separation designated position PO is set.

When this process is finished and the copy key is pressed,
To determine whether the optical system is at the home position 1
) If No, position and return the optical system to the home position (2) and return to step (1).

On the other hand, if the determination in step (1) is YES, it is determined whether the designated area ℃1 is registered as a blue filter by hue detection by the hue detection unit 63) YES
If S, set the filter of the color separation filter 31 to blue 4) Proceed to step (6) or later; if NO, set the filter of the color separation filter 31 to blue 5),
Proceed to step (6) and subsequent steps.

Next, the optical system starts scanning 6), and the area l! When the scanning is completed, a drive command is sent to the actuator M1 that drives the color separation filter 31 to switch and set the filter color to red (7).
8).

Next, it is determined whether or not the filter color switching has been completed.9) If YES, the color separation processing for the area 1□ is continued.

On the other hand, if the determination in step (9) is No, a signal is output to invalidate the output of the image reading section 5a (10), and the process returns to step (9).

Thereby, it is possible to separate a plurality of color image areas on a document while scanning one document. Moreover, the above step (10) prevents image reading errors during filter switching of the color separation filter 31.

〔Effect of the invention〕

As described above, the present invention includes a light amount adjusting means for adjusting the amount of light transmitted through the color separation filter means and incident on the image reading means based on the variation in the amount of light exposed to the original from the original scanning unit. Therefore, even if the amount of light with which the original scanning unit exposes the document changes, the amount of light that passes through the image reading means through the color separation filter means can be controlled to be constant, and the color image by the image reading means based on the fluctuation in the amount of light can be controlled to be constant. This has an excellent effect of preventing misidentification of region separation.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram showing an example of a color information separation device of a copying machine according to an embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating the arrangement of the imaging system shown in FIG. 1. FIG. 3 is an enlarged perspective view of the main parts of the eraser shown in FIG. 1 and its control system, FIG. 4 is a schematic diagram illustrating the color image recognition erase processing operation according to the present invention, and FIG. FIG. 6 is a flowchart explaining the image forming control operation procedure according to the present invention. FIG. 7 is a flowchart explaining the eraser drive control operation procedure shown in FIG. 1.
FIG. 8 is a schematic diagram showing the relative arrangement relationship between the color separation filter and the image reading section shown in FIG. 9 is a circuit block diagram illustrating the configuration of the hue detection section shown in FIG. 1, FIG. 10 is a schematic diagram illustrating the original image hue detection operation by the hue detection section shown in FIG. FIG. 11(a) is a flowchart illustrating an example of the hue state detection and color filter selection setting control procedure by the hue detection unit according to the present invention, FIG. 11(b) is a diagram showing hue state determination reference data, and FIG. 12 is an image A sensor output correction processing circuit diagram of the reading section, FIG. 13 is a flowchart explaining an example of a light amount fluctuation adjustment procedure according to the present invention, and FIG. 14 is a flowchart explaining an example of a one-scan color separation filter switching setting control procedure according to the present invention. It is. In the figure, 5 is a color separation unit, 5a is an image reading section, 6 is a hue detection section, 7 is a controller section, and 8 is an operation section. Fig. 2 M1 Fig. 1. ! ! Table chart bt:R Table chart

Claims (1)

[Claims] A document scanning unit that exposes and scans a document; a color separation filter device that separates a reflected image on the document into a plurality of colors; an image reading device that reads image information transmitted through these color separation filter devices; In a copying apparatus that transfers original images in multiple colors by selected developing units onto a conveyed transfer sheet while erasing an electrostatic latent image formed on a photoreceptor with light in accordance with an output from an image reading means, A copying apparatus comprising a light amount adjusting means for adjusting the amount of light incident on the image reading means via the color separation filter means based on variations in the amount of light exposed to the original from the original scanning unit. Color information separation device.