JPH03209273A - Image forming device - Google Patents

Abstract

PURPOSE:To separate color of a color image which is in a same hue with a different luminance level from an original by setting a threshold value of color separation according to a selected luminance level and hue to be variable, color separating reflected image to be exposed based on that threshold value and reading it. CONSTITUTION:The hue to be color separated is selected by a hue selection means (hue key) 33a, when luminance level against the selected hue is selected by a luminance level selection means (lightness level key) 33b, and the original image is color separated responding to the selected luminance level and hue by a setting means 51a. For example, the threshold value against an A/D transforming device 56 is set to be variable, and the reflected image to be exposed by an analog exposure means (original illuminating lamp) 2 based on the threshold value set to be variable is color separated and read by an image reading means (a driver circuit, the A/D transforming device, and a camera element 4b, etc.,). Thus, the color image in the same hue with a different luminance level can be color separated from the original.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has an analog exposure system and a digital exposure system, and recognizes different color image areas on a document from the reflected light exposed to the document. The present invention relates to an image forming apparatus that forms images of different colors for each region.

[Prior art 1] Conventionally, this type of device, such as an analog q-photography device, has an erase function that erases a latent image by emitting light from, for example, an LED array to an area specified by, for example, a digitizer or numerical input. Models equipped with this have been commercialized. In addition, in the digital copying device, image information read from the league is buffered in the -H memory, and when masking processing is specified for the area data specified from the operation panel, the image information is processed accordingly. There are also models on the market that are configured to perform image processing to convert the image information stored at the specified address into white image information, and to easily make a copy with the specified image masked.

Incidentally, recent image forming apparatuses are configured to accommodate a plurality of developing units in a replaceable manner, and even when performing masking copying or trimming copying as described above, it is possible to make copies in the desired copy color. Or,
There is an increasing demand for obtaining highly designed and impressive copied images by multiple-transferring trimmed images of different colors onto a single transfer sheet.

Furthermore, when there is a red part in a document image, there is a growing demand for automatically copying that part in red.

Therefore, a proposal has been made to automatically select a developing unit from image information color-separated according to a color separation method, and to obtain a copy image having the same color as the original image through multiple processes.

[Problem to be solved by the invention]

However, conventional image forming apparatuses are configured to separate images of the same color as the developer contained in the developing unit and form multiple transfers, and therefore cannot be separated unless the brightness is above a certain level. For example, a dark red color with low brightness will not be recognized as red, and will be treated as a black image and developed into black.

For this reason, it has been impossible to select image processing that converts the brightness, such as recognizing even a red color with low brightness as red, and developing with a bright red developer. Furthermore, there are problems in color separation, such as dark red color being separated while dark blue color cannot be separated.Due to the difference in hue, sometimes separation is possible and sometimes it is not possible.

This invention has been made to solve the above problems, and by variably setting the color separation judgment level according to the selected hue and brightness level, the original color can be adjusted according to the desired color brightness. An object of the present invention is to obtain an image forming apparatus that can realize color separation reading processing.

[Means for Solving the Problems 1] The image forming apparatus according to the present invention includes a hue selection means for selecting a hue to be separated, and a brightness level selection means for selecting a brightness level for the hue selected by the hue selection means. a setting means for variably setting a threshold for color separation according to the brightness level selected by the brightness level selection means and the hue selected by the hue selection means; The apparatus is further provided with an image reading means for color-separating and reading the reflected image exposed by the analog exposure means based on the color separation.

Further, the built-in developing unit corresponding to the developed color is simultaneously selected in accordance with the hue selected by the hue selection means.

Further, a color separation condition storage means for storing color separation condition information consisting of the brightness level selected by the brightness level selection means and the hue selected by the hue selection means, and color separation condition information read from the color separation condition storage means. and image reading means for color-separating and reading the reflected image exposed by the analog exposure means based on the above.

[Operation] In the present invention, when a hue to be separated is selected by the hue selection means and a brightness level for the selected hue is selected by the brightness level selection means, the setting means selects the selected brightness level and hue. The threshold value for color separation is variably set according to the hue selected by the selection means,
The image reading means color-separates and reads the reflected image exposed by the analog exposure means based on a variably set threshold value, making it possible to color-separate color images with different brightness levels within the same color tone from the original. do.

Further, the built-in developing unit corresponding to the developed color is simultaneously selected according to the hue selected by the hue selecting means, and the developing unit containing the developer of the corresponding color is selected in conjunction with the hue selection process by the hue selecting means. It is possible to automatically select from multiple built-in developing units.

Further, color separation condition information consisting of the brightness level selected by the brightness level selection means and the hue selected by the hue selection means is stored in the color separation condition storage means, and is read out from the color separation condition storage means as necessary. To make it possible to color-separate and read a reflected image exposed by an analog exposure means based on color separation condition information read out by an image reading means, and to perform color separation from a document with a simple operation.

Embodiment J FIG. 1 is a cross-sectional view illustrating the configuration of an image forming apparatus showing an embodiment of the present invention. Reference numeral 1 denotes an original table glass, on which an original to be described later is placed at a predetermined position.

Reference numeral 2 denotes an original illumination lamp composed of, for example, a halogen lamp, which exposes the original placed on the original table glass 1. 3
Scanning mirrors a to 3c are housed in an optical scanning unit (not shown) and guide reflected light from the document to the CCD unit 4 while reciprocating in the main scanning direction. The CCD unit 4 includes an imaging lens 4a, and an image sensor 4b (a driver circuit described later), which is configured of a COD, for example, and has a switching filter that separates the reflected light into colors based on hue information designated by a switch box described later. The image reading means is composed of an A/D converter, an image sensor 4b, etc.), an imaging lens 40 for the image sensor, and the like. Reference numeral 5 denotes a folding mirror, which folds back the reflected light imaged by the imaging lens 4a onto the photosensitive drum 6.

Reference numeral 7 denotes a pre-exposure lamp that eliminates the charge on the photosensitive drum 6 in preparation for the image forming apparatus. A charger 8 charges the photosensitive drum 6 uniformly. Reference numeral 9 denotes a laser unit constituting a digital exposure means, which is composed of, for example, a semiconductor laser, and is used to scan the image sensor 4b in parallel with the document exposure of the optical scanning unit.
A laser beam is irradiated onto the image area of the photosensitive drum 6 corresponding to the image area detected by the electrostatic latent image, thereby erasing the formed electrostatic latent image.

Reference numeral 10 denotes a built-in fixed type developer, which stores, for example, black toner. Note that a plurality of fixed type developing devices may be provided instead of one. Reference numeral 11 denotes a replaceable developing unit, which is configured so that the user can easily install it in a predetermined position within the apparatus.

Developers for blue and green are in development unit 1 for each color.
1 is filled. Note that the developing unit 11 is replaced by a developing device automatic replacing device (not shown). 12a, 1
Reference numeral 2b denotes a paper feed cassette, in which the transfer sheet is fed into the apparatus by driving each paper feed roller 13a, 13b, and is temporarily stopped at the position where the registration roller 14 is disposed, so that the leading edge of the transfer sheet meets the image formed on the photosensitive drum 6. It is re-fed at the correct timing.

A transfer charger 15 transfers the toner image developed on the photosensitive drum 6 onto a fed transfer sheet.

A separation charger 16 separates the transfer sheet after the transfer operation from the photosensitive drum 6. 17 is a conveyor belt that conveys the transfer sheet after the transfer process has been completed to the fixing device 18;
The fixing device 18 fixes the image.

Reference numeral 19 denotes a flapper that controls the conveyance bus of the transfer sheet after the fixing process in either the direction in which the paper discharge tray 2o or the intermediate tray 22 is disposed.

Feed rollers 21a to 21d feed the transfer sheet, which has been subjected to the -degree fixing process, to the intermediate tray 22 while being reversed (multiple) or non-reversed (double-sided).

Reference numeral 23 denotes a re-feeding roller which feeds the transfer sheet placed on the intermediate tray 22 again to the registration rollers 14 via the paper bus 24.
Transport it to the installation position.

Reference numeral 25 denotes a controller section, which includes a microcomputer, an image area processing section, etc., which will be described later, and includes a hue key 33a (functions as a hue selection means) and a brightness level key 33b (functions as a hue selection means) of a switch box 33 provided in the operation section 26. For example, a setting means 50a is provided for processing the brightness level information 1 and phase information selected from (functioning as means) and variably setting a threshold value for an A/D converter, which will be described later.

In the image forming apparatus configured in this manner, the hue to be separated is selected by the hue selection means (the hue key 33a in this embodiment), and the brightness level for the selected hue is determined by the brightness level selection means (in this embodiment, the hue key 33a). In the example, when selected by the brightness level key 33b), the setting means 51a
For example, a threshold value for an A/D converter is variably set, and the image reading means (driver circuit described later, A
/D converter, image sensor 4b, etc.) separates and reads the reflected image exposed by the analog exposure means (original illumination lamp 2) based on a variably set threshold value. , it is possible to color-separate color images having different brightness levels within the same tone from a document.

Further, depending on the hue selected by the hue key 33a, a developing unit 11 or a second developing unit (not shown) corresponding to the developing color is selected. Third
It is possible to simultaneously select two replaceable developing devices, and to automatically select a developing unit containing a developer of a corresponding color from a plurality of developing units in conjunction with hue selection processing by the hue key 33a.

FIG. 2 is an enlarged perspective view of main parts for explaining the configuration of the laser unit 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, 31 is a manuscript, for example, the letter P (red)
This figure shows a state in which the developing image 31a is placed on the document table glass 1 with the image surface facing downward. 32 is an image area processing unit;
The switching filter color provided on the image sensor 4b is selected based on the hue specified from the switch pock 33 provided on the operation unit 26, and the image area information detected from the original 31 exposed in this state is divided into a predetermined scanning area ( Folding mirror 5
(from the exposure position scanned by the laser unit 9 to the exposure position of the laser beam scanned by the laser unit 9), and the driver Erase information is output to the circuit 34. This erase information is determined based on the image area information stored in the image area processing section 32. Then, the photosensitive drum 6 is irradiated with a laser beam to erase the latent image formed on the photosensitive drum 6.

Next, referring to FIG. 3, the image sensor 4 shown in FIG.
The image reading process of b will be explained.

FIG. 3 is a block diagram showing an example of a drive circuit for the image sensor 4b shown in FIG. 1, and the same components as in FIG. 1 are given the same reference numerals.

In this figure, numeral 51 is a microcomputer that collectively controls each section based on a series of copy sequence programs stored in a ROM (not shown). Reference numeral 50a denotes a setting means that variably sets, for example, a threshold value for color separation, for the A/D converter 56, in accordance with the selected brightness level and the hue selected by the hue selection means. Note that the microcomputer 51 activates the latch circuit 52 when color separation, multicolor development, and variable magnification are specified from the operation unit 26.
The count data of the reference clock supplied from the oscillator 53 is output to the reference clock. 54 is a counter circuit that counts the reference clock supplied from the oscillator 53 based on the count data latched in the latch circuit 52;
Predetermined pulse signals to be supplied to the image sensor 4b, that is, shift pulse SH, reset pulse R3, and transfer pulses PL and P2 shown in FIG. 4 are generated and output at predetermined timings.

A driver circuit 55 amplifies the analog image signal output from the image sensor 4b. 56 is an A/D converter that converts the analog image signal output from the image sensor 4b into digital image data having, for example, 8-bit weight;
It is output to the subsequent image area processing section 32.

The image area processing section 32 separates the digital image data into black image data and other color image area data, and generates erase data for driving the laser unit 9.

The switch box 33 is provided with a hue key 33a and a brightness level key 33b.
The developing device 10. shown in FIG. An instruction to select one of the developing units 11 is also output to the microcomputer 51 of the controller section 25.

That is, the hue key 33a is configured to work in conjunction with each other as a composite key that serves both the hue selection function and the color designation of the developing unit.

FIG. 4 is a timing chart explaining the output timing of each signal shown in FIG. corresponds to Transfer pulse PL,
P2 is a pulse signal for transferring signal charges in the transfer section to a shift register (not shown) one stage at a time, and since it is a dual channel system, the number of transfer pulses is two. The reset pulse R3 is a signal for discharging accumulated charges, and returns each pixel to its initial state. OUT indicates charge output.

Next, the principle of color separation processing in the image forming apparatus according to the present invention will be explained with reference to FIGS. 5 to 8.

FIG. 5 is a characteristic diagram illustrating the spectral sensitivity characteristics of the image sensor 4b and color filter shown in FIG. 1, where the vertical axis shows the spectral sensitivity and the horizontal axis shows the wavelength (nm).

As can be seen from this figure, the amount of light received by the image sensor 4b depends on the spectral characteristics of the light source, the spectral reflectance of the document, and the scanning mirror 3.
It is expressed as the product of the spectral reflectance of 8 to 3C, the spectral transmittance of the filter, the spectral sensitivity of the image sensor 4b, etc., and is 600 to 70.
This characteristic has a peak value at a wavelength of 0 nm. Further, the image sensor 4b outputs a sensor output in proportion to the amount of light received.

6 and 7 are characteristic diagrams showing the relationship between hue and sensor output when a red filter is set in the image sensor 4b shown in FIG. 1, where the vertical axis shows the sensor output and the horizontal The axis indicates hue.

As you can see from these figures, when a document with a white background and black and red images is read with a red filter set, the sensor output is only for colors with high spectral reflectance in the red region, that is, white and red. becomes thick (see Figure 6).

However, when reading a document containing red images with the same hue, white background, and low brightness level, only the sensor output for colors with high spectral reflectance in the red region, that is, for white, increases (see Figure 7). ), a situation may occur where the original image is mistakenly recognized as black.

Therefore, if the document to be color separated has a dark red image with low brightness even though it has the same red hue, red should be selected using the hue key 33a provided in the switch box 33. In this embodiment, this selection instruction causes the color of the developing unit to be (In other words, the hue key 33a is also used as a developing color selection switch.) Furthermore, when the brightness level key 33b is used to select, for example, "darker", these color separation condition information are sent to the microcomputer 51 of the controller section 25. The slice level (threshold) for the analog image signal that is input and output from the image sensor 4b by the setting means 50a is shifted and set to be lower than the normal slice level, as shown in FIG.

FIG. 8 is a characteristic diagram illustrating the slice level variable setting processing operation by the setting means 50a shown in FIG. 3, where the vertical axis shows the sensor output and the horizontal axis shows the hue.

As can be seen from this figure, the slice levels Ra, Rw, and RR are slices that slice the sensor output when the red filter is set for black, white, and red images, and the slices slice the sensor output of a red image with a low brightness level. If the level is R, and the sensor output at the time of color specification is RT, then the slice level R3 is the slice level of the A/D converter 56 set by the setting means 50a so as to satisfy R, <R, <R. Set variably. Therefore, it is possible to separate a low red image area from a document in which red images and black images with low brightness levels coexist as shown in FIG.

Similarly, the case where the blue filter is set on the image sensor 4b will be described with reference to FIGS. 9 to 12 in sequence.

FIG. 9 is a characteristic diagram illustrating the spectral sensitivity characteristics of the image sensor 4b and color filter shown in FIG. 1, where the vertical axis shows the spectral sensitivity and the horizontal axis shows the wavelength (nm).

As can be seen from this figure, the amount of light received by the image sensor 4b depends on the spectral characteristics of the light source, the spectral reflectance of the document, and the scanning mirror 3.
It is expressed as the product of the spectral reflectance of 8 to 3c, the spectral transmittance of the filter, the spectral sensitivity of the image carrier 4b, etc., and is 400 to 50.
This characteristic has a peak value at a wavelength of 0 nm. Further, the image sensor 4b outputs a signal proportional to the amount of light received.

10 and 11 are characteristic diagrams showing the relationship between hue and sensor output when a blue filter is set in the image sensor 4b shown in FIG. 1, and the vertical axis shows the sensor output,
The horizontal axis indicates hue.

As can be seen from these figures, when a document with a white background and black and blue images is read with a blue filter set, the sensor output is only for colors with high spectral reflectance in the blue region, that is, white and blue. becomes larger (see Figure 10)
.

However, when reading an original with a white background containing a blue image with the same hue and low brightness level, only the sensor output for colors with high spectral reflectance in the blue region, that is, white, becomes large (see Figure 11). ), a situation occurs where the original image is mistakenly recognized as black.

Therefore, if the document to be color separated has a dark blue image with the same blue hue but low brightness, use the hue key 33a provided in the switch box 33 to select blue, and then use the brightness level key 33b to select, for example, "dark". When instructed,
These color separation condition information are input to the microcomputer 51 of the controller section 25, and the setting means 51a sets the slice level (threshold value) for the analog image signal output from the image sensor 4b normally as shown in FIG. is set lower than the slice level of

FIG. 12 is a characteristic diagram illustrating the slice level variable setting processing operation by the setting means 50a shown in FIG. 3, where the vertical axis shows the sensor output and the horizontal axis shows the hue.

As can be seen from this figure, the slice levels Be, By, and BR are the slice levels that slice the sensor output when the red filter is set for black, white, and red images, and the slice levels that slice the sensor output of the blue image with a low brightness level. If the level is B, and the sensor output when specifying a color is BT, then the setting means 50a varies the slice level of the A/D converter 56 so that the slice level B3 satisfies Ba < Bs < Ba. Set. Therefore, it is possible to separate a low blue image area from a document in which blue images and black images with low brightness levels coexist as shown in FIG.

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

FIG. 13 is a schematic diagram illustrating the color image recognition erase processing operation. Reference numeral 41 denotes a document, which is composed of a red image 41R, a black image 41B, and the like.

42 is a multiple first side transfer image sheet, switch pock 3
If, for example, red is specified by the copy color specification from the hue key 33a of No. 3, only the black image 42B is transferred,
The shaded area is the erase area. That is, the eraser functions until the image area is detected, and the red image 41R is erased.

Reference numeral 43 designates a multiple second side transfer image sheet, and when, for example, red is specified as a copy color for the multiple first side transfer image sheet 42, the erase process is performed exclusively on the first side, i.e. The black image 41B on the original 41 is erased (the shaded area in the figure), and only the red image 43R is transferred.

The original 41 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 33. For example, if red is specified by this copy color specification,
The developing unit 11 is selected, and the electrostatic latent image formed on the photosensitive drum 6 can be developed into red.

On the other hand, the image area processing section 32 switches and sets the color of the switching filter provided in the image sensor 4b to red based on the copy designation specified from the switch box 33, and also sets the multiple copy mode. When the first multiple exposure of the original 41 is started in this state, the red image 41R on the original 41 is removed by the switching filter provided on the image sensor 4b, and the reflected light in the sub-scanning direction is sequentially transferred to the image sensor 4.
The image area processing section 32 outputs erase information to the driver circuit 34 until the leading edge of the black image 41B area in the document 41 is detected, and when the leading edge of the black image 41B area is captured, the image area An off command is output from the processing unit 32 to the driver circuit 34, and the multiple one-sided transfer image sheet 4
A black image 42B is transferred to the photosensitive material 2 and formed by a known electrophotographic process. The conveyance of the sheet on which the image has been formed is controlled by a flapper 19 in the direction of an intermediate tray 22,
The sheet is fed to the re-feeding roller 23 position, and is conveyed to the registration roller 14 position based on a drive command from the image area processing section 32, where it is temporarily stopped. In this state, exposure of the document on the second side of multiplexing starts, and in parallel with the exposure of the document, the document 41
The black image area information inside is stored in an internal memory (not shown) of the image area processing section 32. Based on the black image area information stored in the internal memory, the image area processing section 32 outputs erase information to the driver circuit 34, and the tip of the image area stored in the internal memory of the image area processing section 32 is removed from the laser unit 9. When reaching the eraser beam irradiation position of the photosensitive drum 6 to be scanned, the photosensitive drum 6 is irradiated with an erase beam (laser beam in this embodiment) to erase the electrostatic latent image corresponding to the formed black image 41B. .

Therefore, the red image 41 is not irradiated with the erase beam.
Only an electrostatic latent image of R is formed on the photosensitive drum 6, and only this electrostatic latent image is developed by a developing unit 11 containing a red developer. A two-sided transfer image sheet 43 is obtained, only the red image 43R is transferred and fixed, and the shaded area is output with the erased state. As a result, a black image 42B, = red, is printed on the multiple second-side transfer image sheet 43. A multiple cropped image of image 43R is formed.

The image area information stored in the internal memory of the image area processing section 32 is image information from the exposure position scanned by the folding mirror 5 to the exposure position of the laser beam scanned from the laser unit 9.

FIG. 14 is a flowchart showing an example of an image forming sequence in the image forming apparatus according to the present invention. Note that (1) to (9) indicate each step.

First, the controller unit 25 determines whether automatic two-color mode has been designated by the operation unit 26 (1) If no, waits for the copy key provided on the operation unit 26 to be pressed (8), and if pressed, returns to normal mode. Execute the monochrome image forming process 9) and make the original image black.

Develop in monochrome with red and blue to complete the process.

On the other hand, in step 2, if the judgment in step 11 is YES, wait for the hue to be separated to be specified by the hue key 33a of the switch box 33. When the hue is specified, the brightness level is changed by the brightness level key 33b. Determine whether the instruction has been given. 3) If NO, specify the standard brightness level set in advance for each hue. 4) Proceed to step (5) or later; if YES, use the brightness level key 33b.
5) Wait for the copy key to be pressed. 6) When the copy key is pressed, execute the automatic two-color image forming process as described above. 7). end.

In the above embodiment, the case where the brightness level for which color separation is desired is specified by the brightness level key 33b has been described, but prior to color separation processing, the user may cause the image pickup device 4b to read a document containing an image of the color desired to be color separated. (briscan), the controller unit 25 may read the output of the image sensor 4b, determine a threshold value that can perform color separation that is optimal for the brightness level, and finely set the slice level.

Further, the color separation condition information instructed from the switch box 33 or the like or the external separation condition information determined by the controller section 25 by reading the original by the image sensor 4b is rewritably registered in the internal memory (backed up). By configuring the image forming sequence by color separation to be executed based on the color separation condition information stored in the internal memory, complicated key operations can be eliminated and the color separation processing condition operations corresponding to the original can be greatly simplified. It can be relaxed.

〔Effect of the invention〕

As explained above, the present invention includes a hue selection means for selecting a hue to be separated, a brightness level selection means for selecting a brightness level for the hue selected by the hue selection means, and a brightness level selection means for selecting a brightness level for the hue selected by the hue selection means. a setting means for variably setting a threshold value for color separation according to the brightness level and hue selected by the hue selection means; and exposure by an analog exposure means based on the threshold value variably set by the setting means. Since an image reading means for color-separating and reading the reflected image is provided, color images of the same hue and different lightness on the document can be recognized with high precision and color-separated.

Further, since the built-in developing units corresponding to the developed color are simultaneously selected according to the hue selected by the hue selection means, it is possible to automatically select the interlocking developing units with a small number of selection instructions.

Further, a color separation condition storage means for storing color separation condition information consisting of the brightness level selected by the brightness level selection means and the hue selected by the hue selection means, and color separation condition information read from the color separation condition storage means. Since the image reading means is provided for color-separating and reading the reflected image exposed by the analog exposure means based on The color separation condition information setting process can be relaxed.

Therefore, excellent effects such as image formation processing in the color separation mode can be realized reliably with good operability even for documents having the same hue but different brightness levels are achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating the configuration of an image forming apparatus showing an embodiment of the present invention, and FIG. 2 is an enlarged perspective view of essential parts illustrating the configuration of the laser unit shown in FIG. 1 and its control system. , FIG. 3 is a block diagram showing an example of the driving circuit of the image sensor shown in FIG. 1, FIG. 4 is a timing chart explaining the output timing of each signal shown in FIG. 3, and FIG.
The figure is a characteristic diagram explaining the spectral sensitivity characteristics of the image sensor and color filter shown in Fig. 1, and Figs. 6 and 7 show the characteristics when a red filter is set on the image sensor shown in Fig. 1. FIG. 8 is a characteristic diagram showing the relationship between hue and sensor output. FIG. 8 is a characteristic diagram explaining the slice level variable setting processing operation by the setting means shown in FIG. 3. FIG. Characteristic diagram explaining the spectral sensitivity characteristics of the image element and color filter, 1st
0 and 11 are characteristic diagrams showing the relationship between hue and sensor output when a blue filter is set in the image sensor shown in FIG. A characteristic diagram explaining the slice level variable setting processing operation by
FIG. 13 is a schematic diagram illustrating the color image recognition erase processing operation, and FIG. 14 is a flowchart illustrating an example of an image forming sequence in the image forming apparatus according to the present invention. In the figure, 4 is a CCD unit, 25 is a controller section, 2
6 is an operation unit, 33a is a hue key, 33b is a brightness level key, and 50a is a setting means. Figure 7 Figure Hue Figure Wavelength Figure Hue Figure 0 Figure Hue 11 Figure 2 Figure 3

Claims (3)

[Claims] (1) A plurality of developing units that develop the electrostatic latent image formed on the photoreceptor in multiple colors, an analog exposure means that exposes the document placed on the document table, and the analog exposure means are independent of each other. an image forming apparatus that is capable of multiple transfer formation of developed images onto a recording medium; A brightness level selection means for selecting a brightness level for the hue selected by the hue selection means, and a threshold value for color separation according to the brightness level selected by the brightness level selection means and the hue selected by the hue selection means. a setting means for variably setting the
An image forming apparatus comprising: an image reading means for color-separating and reading a reflected image exposed by the analog exposure means based on a threshold value variably set by the setting means. (2) The image forming apparatus according to claim 1, wherein the developing unit corresponding to the developing color is simultaneously selected in accordance with the hue selected by the hue selection means. (3) Color separation condition storage means for storing color separation condition information consisting of the brightness level selected by the brightness level selection means and the hue selected by the hue selection means, and color separation conditions read from the color separation condition storage means. 2. The image forming apparatus according to claim 1, further comprising image reading means for color-separating and reading the reflected image exposed by said analog exposure means based on information.