JPH0432364A - Color picture recorder - Google Patents

Abstract

PURPOSE:To improve the color reproducibility in color outside the color reproduction range of a recording system by selecting a type of an original deciding a color of a color picture and providing a color compression means compressing an information signal into a color information signal capable being recorded by a recording means in an achromatic direction to the recorder. CONSTITUTION:A type of a color original is selected and a color information signal of the color original is inputted. Then a color compression means in matching with the type of the selected color original is used to obtain a color compression color information through the color compression conversion and matrix conversion is applied to the color compression color information to generate a printer control signal so as to obtain a same color as that represented by the color information signal and the data is recorded by using ink or toner in cyan, magenta and yellow according to the generated printer control signal. Thus, the color picture with sufficiently excellent color reproducibility is recorded to various color originals even in a color at the outside of color reproduction of the recording system.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a color image recording device, and more specifically, in a system where the input color reproduction range and the output color reproduction range are different, the present invention relates to a color image recording device. The present invention relates to a color image recording device capable of color reproduction.

[Prior Art] Conventionally, this type of color image recording device inputs a color information signal of a color original, and converts the color information signal in the achromatic direction.
It is compressed and converted into a color recordable by a recording means according to a certain rule.

A printer control signal is generated by performing matrix conversion on the compressed color information signal so that the recorded color is the same as the color indicated by the color information signal, and cyan, magenta, yellow is generated according to the obtained printer control signal. Color recording was performed using ink or toner.

[Problems to be Solved by the Invention] In general, the color reproduction range of an input system varies depending on the type of original that makes up the color of the color original, as shown in Figure 5. There was a problem that sufficient color compression could not be achieved, and as a result, the hue or brightness of colors outside the color reproduction range would be out of order.

The present invention has been made in order to solve the above-mentioned problems, and provides a color image recording device with sufficiently good color reproducibility even for colors outside the color reproduction range of the recording system for various color originals. is intended to provide.

[Means for Solving the Problems] In order to achieve this object, the color image recording device of the present invention records color information signals using a recording means that can change the color of a color document depending on the type of document constituting the color information signal. It is equipped with color compression means for compressing and converting colors into possible colors.

[Function] The color image recording device of the present invention having the configuration described in 1.
First, the type of color original is selected and the color information signal of the color original is input. Then, color compression conversion is performed on the color information signal using a color compression means suitable for the type of the selected color original to obtain a color compression color information signal, and matrix conversion is performed on the color compression color information. A printer control signal is generated so that the recording color is the same as the color indicated by the color information signal, and color recording is performed using cyan, magenta, and yellow ink or toner according to the generated printer control signal.

[Example] Hereinafter, an example of embodying the present invention will be described with reference to the drawings.

First, the overall configuration of the digital color copying machine of this embodiment will be explained with reference to FIGS. 1 to 3. The digital color copying machine 1 of this embodiment includes a color original reading section 2, a color image processing section 3, and a color image recording section 4.

A color original reading section 2 is installed at the top of the digital color copying machine 1. A transparent document table 5 on which a color document is placed and a document cover 6 that can cover the transparent document table and hold down the color document are provided above the color document reading section 2. Further, a scanner light source fluorescent lamp 7 is provided below the transparent document table 5 so as to extend in the front-rear direction in FIG. 1, and the scanner light source fluorescent lamp 7 generates light toward the transparent document table 5. It is configured as follows.

The movable reflecting mirror 8 is installed on a movable table 10'2 for moving the scanner light source fluorescent lamp 7, and is configured to reflect light emitted from the scanner light source fluorescent lamp 7 and reflected by the color original. Lens scope 1 is installed on a movable table 10 so as to concentrate the light reflected by the movable reflecting mirror 8. A filter 12 for decomposing the light concentrated by the lens 11 into red, green, and blue components is a solid-state image sensor (CC) that takes in the decomposed light and converts the decomposed light into an electrical signal.
D) 13, and both the filter 12 and the solid-state image sensor 3 are installed on the movable table 10. The light source moving device 9 is configured to move the movable table 10 in the left-right direction in FIG. 1 together with the scanner light source fluorescent lamp 7, the movable reflector 8, the lens 11, the filter 12, and the solid-state image sensor 13.

At the end of the color document reading section, a document feeder 16 is configured to feed the color document on the document feed table 14 from the color document feed section 15 to the transparent document table 5. Further, on the opposite side of the document feeder 14, there is installed a document discharge tray 17 from which a color document is discharged after copying. Next to the document cover 6, an operation panel 46 is installed which includes a photo document selection button 41, a print document selection button 42, a copy document selection button 43, other document selection buttons 44, and a copy start button 45.

The color image recording section 4 is constructed at the bottom of the digital color copying machine 1. The color image recording section 4 includes a laser modulation unit 26 that emits laser light to the polygon mirror 25 based on a laser drive signal from the laser control section 24 . The photosensitive drum 27 is configured to be exposed to laser light reflected by the polygon mirror 25. Further, the charger 28 is arranged around the photoreceptor drum 27 so as to uniformly charge the photoreceptor drum 27 negatively. The electrostatic latent image on the photosensitive drum 27 created by applying a laser beam to the photosensitive drum 27 charged by the charger 28 is colored cyan,
A cyan developer 29, a magenta developer 30, and a yellow developer 31 are configured to adhere magenta and yellow toners.
is configured. Also, a cyan toner supply device 32 and a magenta toner supply device 33 supply toner to each developing device.
, the yellow toner supply device 34 is installed at the bottom of the first image recording section 4. Further, a cleaner 35 is installed around the photoreceptor drum 27 to remove toner from the photoreceptor drum 27 to which toner has adhered. A transfer drum 37 that transfers the toner on the photoreceptor drum 27 to the recording paper supplied from the supply case 36 and a fixing unit 38 that heat-fixes the transferred recording paper are installed in front of the photoreceptor drum 27. has been done. A paper feed section 40 is configured above the supply case 36 for discharging the fixed paper to an output tray 39.

The color image processing unit 3 is a solid-state image sensor], an analog-to-digital converter (A/D converter) that converts a color document information signal corresponding to the color information signal obtained from the solid-state image sensor from an analog electrical signal to a digital electrical signal. 18, a document storage device (image memory) 19 that stores part of the color document information using digital electrical signals, a table showing the color reproduction area of various documents, a table showing the color reproduction area of this copying machine, and a color image record. Regarding colors within the color reproduction area of section 4, various image processing is performed using a ROM 20 that stores color correction coefficients etc. determined in advance so as to achieve sufficient color reproduction, and a RAM 21 that stores each calculation result. Based on the CPU 22 and the signal after color correction, the color image recording section 4
and a laser control section 24 that drives the laser 23.

Next, referring to FIGS. 1 to 4 (7), the operation of the digital color copying machine 1 of this embodiment will be explained.

First, the type of original to be copied is selected using the original selection buttons 41 to 44 on the operation panel 46. Then, the user presses the copy start button 45.

Then, the color original on the original feeder table 14 is transferred to the original feeder 1.
6 to the transparent document table 5 (or the document cover 6 may be opened directly and placed on the transparent document table 5), and the scanner light source fluorescent lamp 7 is moved by the light source moving device 9 in the sub-scanning direction.
The emitted white light is reflected by a moving reflecting mirror 8, passes through a lens 11 and a filter 12, and is converted into an electrical signal by a solid-state image sensor 13. The filter 12 is divided into parts that transmit only the red, green, and blue components, and the moving stage 10 is moved by the drive of the light source moving device 9, and the filter 12 is divided into parts for each line in the main scanning direction. The colors change in the order of red, green, and blue.

The analog electrical signal obtained from the solid-state image sensor 13 is sent to an analog-to-digital converter 1.8 for each pixel (pixel of interest).
The digital color signal is converted into a digital color signal and stored in the document storage device 19. Color correction processing is performed on the stored digital signal of the pixel of interest using the CPtJ22 as follows.

First, in step SP1, the digital signal of the pixel of interest is converted into a value of the CIE-L""a"b1 color system.In this case, the input RGB signal is converted into CIE by linear conversion if the router conditions are satisfied in the input system. - Can be converted to xyz values.And from CI E-XYZ values (X, Y, Z)
IE-L"a'"b*color system value (conversion into L", a", and b can be performed as shown in the following formula.

■Bu = 116 X (Y/Y,) ”/”-16...
...(1) a ”=500 x ((X/X,) ”” −(Y
/Y,,) "3) ......(2) b"=2ooX ((Y/Y,,)"-(Z/Z,)
1'3) ......(3) However, Xo,,Y,,,2. is a fully diffused CIE-X
YZ tristimulus value.

Next, in step SP2, the distance M1 from the target pixel to the achromatic color (hereinafter referred to as target achromatic color) of the target pixel is determined as shown in the following equation.

M1= ((L"-Ll) 2+a"+b") "'・
...(4) However, L" is the L0 value of the CIE-T-"a"b" color system of the target achromatic color, and generally a value of 50 to 6o is used.

Then, in step SP3, the distance M2 from the target achromatic color of the color reproduction range of the recording system in the hue and brightness directions from the target achromatic color of the pixel of interest is calculated in advance from the table tab1e stored in the ROM 20. Refer to as in the expression.

θ=at an ((L"-I, *') 2/
(all2 + b112)1″) ・・・・・・
・(5) φ−at a n (b”/a”) --
(6) M2=table[θko [φ] --
----(7) Also, in step SP4, press the document selection button 4 in the hue and brightness direction from the target achromatic color of the pixel of interest.
The distance M3 of the color reproduction range of the document selected in steps 1 to 44 from the target achromatic color is also referred to in the table table2, which has been previously determined and stored in the ROM 20, as in equations (5) to (7) above. .

In step SP5, the distance M of the pixel of interest from the target achromatic color is determined to be a distance jll1M3 in the color reproduction range of the recording system.
Find out if it's in the 70%.

If it does not exist, color compression conversion is not performed, and if it does, in step SP6, the distance M4 of the pixel of interest from the target achromatic color after color compression is determined as shown in the following equation.

M4=M2-0.3xM2/ (M3-0.7xM2)
X (M2-Ml) (8) Then, in step SP7, CI E- of the pixel of interest is calculated as shown in the following formula.
Change the values of the L"a"b" color system.

L9□= (L"-L")XM4/M1+L"...
...(9) a"2=a"XM4/Ml -(ko, 0
)b”2=b”XM4/Ml ・・・・・・(1
, 1,) Then, in step SP8, the RGB values of the original scanner input color system are converted again. Next step SP9
Then, color correction processing is performed as shown in the formula below, and cyan, magenta, and yellow printer control signals are determined.

However, C, M, and Y are cyan, magenta, and yellow printer control signals, and all is a color correction coefficient.

The printer control signal for each component obtained by the color correction is sent to the laser control unit 24, and according to this data, a laser beam is emitted.The laser beam is reflected by the polygon mirror 25 and uniformly charged by the charger 28. Charged photosensitive drum 2
7, a latent image is created on the photosensitive drum 27.

According to the latent image, by color separation of its corresponding data,
It is developed (toner is attached) by either the cyan developer 29, the magenta developer 30, or the yellow developer 31. Then, the recording paper fed from the paper feed case 36 is wound around the transfer drum 37, and the developed image is transferred from the photosensitive drum 27 to the recording paper. Further, toner is removed from the photosensitive drum 27 using a cleaner 35. The transferred recording paper is thermally fixed in the fixing section 38 in the middle of the paper feeding section 40 and outputted to the output image tray 39.

It should be noted that the present invention is not limited to the above-mentioned embodiment (various changes can be made without departing from the spirit thereof.For example, in this embodiment, a color masking method is adopted for the color correction processing itself). However, the color compression part described above may be incorporated into the look-up table using a color correction method using interpolation processing such as a look-up table.Furthermore, in this embodiment, a digital color copying machine is used. However, it is a color document that does not have a color document reading section.
A printer is also fine.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, it is possible to produce color images with sufficiently good color reproducibility even for colors outside the color reproduction range of the recording system for various color originals. can be recorded.

[Brief explanation of the drawing]

FIG. 1 shows an example of a digital computer embodying the present invention.
FIG. 2 is a block diagram showing the entire color copying machine; FIG. 2 is a block diagram showing the operation panel of the color document input section of the digital color copying machine; FIG.
4 is a block diagram of a color image processing section of the color copying machine according to this embodiment, and FIG. 4 is a flowchart showing the operation of the circuit of the color correction section of the digital color copying machine according to this embodiment. , FIG. 5 is a diagram showing the color reproduction range of each color material. 1 is a digital color copying machine, 2 is a color document reading section, 3 is a color image processing section, 4 is a color image recording section, and 1.3 is a solid-state image sensor. 20 is a RAM, 2] is a ROM, 22 is a CPU, 41 is a photo original selection button, 42 is a print original selection button, 4
3 is a copy original selection button of this machine, and 44 is an other original selection button.

Claims (1)

[Claims] 1. An input means for inputting a color information signal corresponding to the color of a color original, a recording means for performing color recording using at least three color materials of cyan, magenta, and yellow; In a color image recording apparatus, the color image recording apparatus includes color correction means for generating a control signal in accordance with the color information signal to the recording means so that the recorded color recorded by the recording means is substantially the same color as the color corresponding to the color information signal. , The color of the color original can be changed depending on the type of original that determines the color of the original,
A color image recording apparatus comprising a color compression means for compressing and converting the color information signal into a color information signal that can be recorded by the recording means in an achromatic color direction.