JP2659969B2 - Image forming device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor image processing apparatus for reading an original photoelectrically by an image sensor and printing the original on recording paper.

(Prior art)

For in-house printing systems or word processors,
Recently, a scanner for image input has been attached.

Handling full color with these devices is difficult to use because not only is the printer and scanner expensive, but the image processing is complicated and the amount of data is enormous.

On the other hand, in the word processor, a product with a thermal transfer printer equipped with a multicolor ribbon such as black and red has also appeared, which enables multicolor printing by specifying a range and a color.

On the other hand, for example, only red is decomposed and red and black 2
There are devices that print in color. An original is illuminated by two light sources, a green light source and a red light source, and the red portion is subjected to color separation by utilizing the fact that there is almost no signal when illuminated by the red light source.

Then, the portion where black is detected is printed in black, and the portion where red is detected is printed in red.

However, for landscape photography, etc.,
Many are green, for example, almost blue in a seaside photograph, and mostly green in a forest photograph. However, since only red is extracted, the image as a whole is not different from black and white.

[Purpose] The present invention has been made in view of the above points, and reproduces a color different from the color of a recording material existing in a document in a pseudo manner using both of two recording materials for one pixel. The purpose is to:

〔Example〕

 Hereinafter, the present invention will be described based on preferred embodiments.

FIG. 1 is a schematic configuration diagram of the apparatus of the present embodiment. 1 is
A green LED having a peak wavelength of 560 nm, which is the first illumination light source, and 2 has a wavelength of 6, which is the second illumination light source.
This is a 60nm red LED. FIG. 2 shows the wavelength characteristics of the LEDs 1 and 2. The reflected light from the document 3 illuminated by the LED 1 or the LED 2 forms an image on the image sensor 5 by the short focus lens array 4. The image sensor 5 is a CCD line sensor in which hundreds to thousands of photoelectric conversion elements are arranged in a line, and converts the intensity of received light into an electric signal.
The image sensor 5 performs two-dimensional image formation by electrical scanning in the main scanning direction, which is the direction in which the photoelectric conversion elements are arranged, and mechanical scanning by moving the reading position in the sub-scanning direction perpendicular to the main scanning direction. Perform reading.

Reference numeral 8 denotes a roller, which rotates as the housing 9 is manually moved, and rotates the encoder plate 10. The encoder plate 10 is provided with slits along the circumference, and intermittently shields the photo sensor 11 with the rotation thereof.
The light-shielding timing is set so that one pulse is generated for a movement amount of the housing 9 of 0.05 mm.

FIG. 3 is an electric block diagram of the apparatus of this embodiment. 43
Is a control circuit, which controls the entire electric system in synchronization with a pulse signal from the photo sensor 11. 50 is a switching circuit,
LED1 and LED2 are turned on alternately according to a command from the control circuit 43 synchronized with the pulse signal of the photosensor 11. Further, an image is read by the sensor 5 in synchronization with the alternate lighting of the LEDs 1 and 2, and the read information is sent to the signal processing circuit 51. In accordance with a signal from the signal processing circuit 51, an image is printed on a recording material by the printer 36.

The printer 36 is, for example, a thermal transfer type dot printer, has a dot pitch of 0.1 mm, and prints red and black dots. As the printer, other types of printers such as an ink jet printer, an LED printer, and a laser beam printer may be used.

Reference numeral 54 denotes a dot memory pattern which stores a plurality of types of dot patterns having different densities for printing the entire image at a uniform density.

Reference numeral 55 denotes a keyboard, which is used by an operator to select an arbitrary pattern and a print color from a plurality of types of dot patterns stored in the dot pattern memory 54.

FIG. 4 is a block diagram of the signal processing circuit 51 shown in FIG. The analog image signal read by the image sensor 5 is
The signal is converted to a digital signal via the A / D converter 31,
The information S1 of one line when is turned on is temporarily stored in the memory 52, and is supplied to the comparison operation circuit 33 together with the information S2 of one line when the LED2 is turned on. Reference numeral 53 denotes a selector for switching and outputting output information of the A / D converter 31 as information S1 or S2 in synchronization with lighting of the LEDs 1 and 2. Comparison operation processing circuit 33
Performs arithmetic processing on the input data, converts the data into red and black print data, and sends the black image and red image data to the RAM 34 and the RAM 35, respectively.

The RAMs 34 and 35 sequentially store the received data. After reading the image, the data stored in RAM
To print the black image on the recording material, and then send the data stored in the RAM to the printer 36 so that the red image is printed over the previously printed screen.

Further, of the patterns stored in the dot pattern memory 54, data corresponding to the pattern specified and selected by the keyboard 55 is sent to the printer 36,
A pattern is printed in a color designated by the keyboard 55 on a recording material on which an image is recorded based on the contents of M34 and M35.

A data processing procedure when a desired image is read by the apparatus configured as described above and mixed color printing of black dots and red dots is performed will be described.

First, when the keyboard 55 is operated to input a desired base color and pattern, the control circuit 43 selects a corresponding pattern from the dot pattern memory 54.

Then, when a print command is sent from the keyboard 55, the control circuit 43 operates each circuit to perform a print operation.

As described above, the analog image data output from the sensor 5 is converted into digital data for each pixel by the A / D converter 31 and input to the comparison operation circuit 33.

Here, the pixel pitch of the image sensor 5 is 0.4 mm, and the dot pitch of the printer 36 is 0.1 mm. That is, since 4 × 4 dots of the printer 36 correspond to one sensor pixel, the comparison operation circuit 33 is used. Is one of the image sensors 5
The pixel data of the pixel is input, and black dot and red dot data to be printed in 4 × 4 dots by the printer 36 are output.

The data processing algorithm of the comparison operation circuit 33 will be described below.

This algorithm makes use of the fact that the output level of the sensor 5 when illuminated by the red LED 2 becomes large with respect to the color containing the red component, and the output level of the sensor 5 when illuminated by the LED 1 and the illumination by the LED 2 In this case, the red level included in the image is extracted from the output level difference of the sensor 5 in this case.

First, the images sequentially exposed from LED1 and LED2 are displayed on LED1 and LED2.
The image information read by the sensor 5 in synchronization with the blinking of
Each A / D to the pixel signals S ₁ and S ₂ is the concentration information of the bit
Convert. Then, in response to the pixel signals S ₁ when illuminated by LED1, it calculates a reference printing density data P _0. Pixel signals S ₁ is a 4-bit, i.e. 16 gradations for one pixel, because the translation to print at 16 dots of 4 × 4, for example if the pixel signal S ₁ is gradation 7, 7 The density can be expressed by the number of dots to be printed in a 4 × 4 print area such as a dot. This is because the calculation constant changes depending on the size of the dot of the printer 1 and if the dot is large, the total number of dots to be printed may be reduced. That reference print density data P ₀ is the Purintodotsuto number calculated in this way.

Then it determines the red level from the pixel signals S ₁ and S ₂ Metropolitan. As image of the original is reddish, and S ₁ the difference between the pixel signals S ₁ and S ₂ is increased, it is possible to calculate the red level from the difference between the S ₁ and S _2. Actually, correction is performed based on experimentally obtained data so that a red level matching the red tint of the document is obtained.

Red level, which represents the ratio of the red to the concentration, taking the difference between the reference print density data P ₀ and the black print density data P _1, and the red print density data P _2.

Such a pixel signals S ₁ and S ₂ Metropolitan according to the algorithm, to calculate the black where a Purintodotsuto number of black and red in a unit area of 4 × 4 print density data P ₁ and red print density data P ₂ be able to.

In the present embodiment, this arithmetic processing is performed by the comparison arithmetic circuit 33 using a ROM. That is, a look-up table is created in the ROM according to the result of the calculation in advance, and the print density data P ₁ and P ₂ are immediately obtained according to the input values S ₁ and S ₂ .

The comparison operation circuit 33 is configured in detail as shown in FIG. 41 is a ROM, having a data bus of 16 bits of 9 bits of the address bus and D ₁₅ to D ₀ of A8 to A0.

4 digital pixel signals S ₁ and S ₂ of the bits are connected to the address bus of the ROM, i.e., the pixel signals S ₁ are sequentially connected to the address A8~A5 of ROM41 from the bits and S ₂ likewise from upper bits The addresses are sequentially connected to the addresses A4 to A1 of the ROM 41. The address A0 of the ROM 41 is connected to the control circuit 43.

42 outputs 16-bit output data of ROM 41 to RAM 34
A selector for selecting whether to output to the RAM 35. In the ROM 41, data corresponding to the result of the arithmetic processing by the processing algorithm described above is stored in advance as a table. Incidentally, the black print density data P ₁ is an even address, and because red print density data P ₂ are are respectively stored in odd address, the control circuit
43, the reading the black print density data P ₁ stored in the even addresses and the row address A0 of ROM 41, and controls to read the red print density data stored in the odd addresses and the A0 high.

The selector 42 sends the 16-bit data read when reading the black print density data P ₁ , that is, the even address, to the RAM 34, and sends the 16 bit data read when reading the red print density data P ₂ , that is, the odd address to the RAM 35. The switching is controlled by the control circuit 43 so as to send out.

As described above, the print density data P ₁ and P ₂ are output from the comparison operation circuit 33 in accordance with the input values S ₁ and S ₂ , and
4, and stored in the RAM 35.

The print density data consists of 16 bits of D ₀ to D _15, corresponds to the print de bracts matrix 4 × 4 as shown in FIG. 6, when the corresponding data is 1, the corresponding position Is controlled so that a dot is driven into the box.

Specifically, in the case where D ₀ and D ₁ is 1, as shown in FIG. 7, dots are driven into the position corresponding to the position D _0, D ₁ in FIG. 6.

The print density data P _1, if the D ₀ depending on the level of concentration of D _1, D ₂ and are sequentially set to be 1, for example, the level of concentration in 16 gradation 7, D ₀ from to D ₆ becomes 1, dots are implanted as shown in Figure 8. On the other hand, the print density data P ₂ to control the red dots is set to sequentially become 1 and D _14, D ₁₃ from D ₁₅ depending on the level of concentration, for example, if the concentration level of 3 D ₁₅ , D ₁₄ , and D ₁₃ become 1, and a dot is formed as shown in FIG.

FIG. 10 shows a state in which the black dot print shown in FIG. 8 and the red dot print shown in FIG. 9 are superimposed. A print as shown in FIG. 10 is visually perceived as one color due to a mixture of black and red, and a mixed color expression is achieved.

Then extracted redness from the output signals S ₁ and S ₂ Metropolitan of the image sensor, the signal processing for calculating describing data for red and black color mixing print. RO mentioned earlier
The data content of M41 is determined based on the processing result described below.

FIG. 12 and FIG. 13 are diagrams showing a part of the output of the image sensor 5 when the halftone portion of the document is read. Here, for example, white has an output of 100 mV, and black has an output of 10 mV. The output when illuminated by the green LED 1 is represented by a black circle and a solid line 100 in FIG. 12. Since the output from the sensor pixel addresses 1 to 3 is about 100 mV, it is determined that the pixel is white, and the output from the addresses 4 to 7 is determined. Since the output is about 40mV, 16
This corresponds to a halftone density level of density 9 in gradation. The concentration of 9 and reference density level P _0.

Next, when illuminated with red LED2, the pixel address of the original
If the image corresponding to 4, 5, 6, 7 is a color other than red, for example, gray or blue, there is basically no change in density, so
Although the outputs of the pixel addresses 1, 2, 5, 6, and 7 of the image sensor 5 are the same, the pixel address 3 of the short focus lens array 4 that guides the reflected light of the original to the image sensor 5 is generated.
A change occurs in the outputs of (4) and (4), which are represented by white circles and wavy lines 101.

In addition, when illuminated by the red LED 2 and the pixels corresponding to the pixel addresses 4, 5, 6, and 7 of the original are red, as indicated by the two-dot chain line 102 in FIG. Five,
The output of 6,7 is also about 100mV, the same output as white. The pixel addresses in FIG. 13 correspond to the addresses in FIG.

That is, according to FIGS. 12 and 13, pixel address 4
Since the output of か ら 7 changes greatly from 40 mV to 100 mV, the pixel is determined to be red. In this case, corresponding to the pixels from the address 4 7, to print the red accordance reference density 9 obtained above as a red print density data P ₂ to 9, will not take place on printing black dots.

By the way, if the image corresponding to the pixel address 5, 6, 7 of the original is not red, such as brown, but reddish, the output when illuminated by the red LED 2 is the white circle in FIG. And the dashed line 103. That is, the output of the pixel addresses 5 to 7 is 70 mV, and the density does not include the red component. In other words, the density of the color other than red is represented by this value. The color density corresponds to 5 of 16 gradations. That is, the black print density data P ₁ is 5, and the implantation of black dots only equivalent to 5 of the reference density 9 obtained in FIG. 12, the difference 4 red print density data P _2, and the 4 only red dots Type. As a result, a mixed color of red and black is expressed.

FIG. 11 is a diagram schematically showing a state in which printing is performed in accordance with print density data indicating a plurality of types of patterns stored in the dot pattern memory 54. That is, the dot pattern memory 54 has a density level of 16
And each of the pattern of the gradation is stored, Figure 11 is the concentration of 2 Dotsutopatan, i.e., in which D ₁₅ and D ₁₄ is subjected to printing in accordance with the continuous data became 1.
That is, the designated color is printed lightly over the entire image.

In this manner, the red level is extracted from the output of the image sensor 5 when illuminated by the green LED 1 and the output of the image sensor 5 when illuminated by the red LED 2, and the pattern of the red dot to be printed and the black dot are extracted. The pattern is determined, mixed color printing of red and black is performed, and the base color is printed on the entire image according to the base color and density designated from the keyboard 55.

For example, if the original is a photo of the sea, if you specify blue as the base color, the sea and sky parts will be bluish, the red beach umbrellas on the sandy beach will be printed in red, and the colors of the original will be rich Is obtained.

Although a manual scanner has been described here, a similar effect can be obtained with a document table scanner. Although green and red are used as the colors of the LED for exposing the original, the present invention is not limited to this. In addition, it is naturally possible to provide three or more colors of LEDs to perform color separation of more colors, and it is also possible to use a light source other than the LEDs as the light source.

〔effect〕

According to the present invention, a color different from the color of the recording material existing in the document is reproduced by using both of the two recording materials for one pixel, thereby making it possible to perform pseudo recording.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a device according to an embodiment of the present invention, FIG. 2 is a diagram showing characteristic curves of an LED light source, FIG. 3 is a block diagram showing the configuration of the device, and FIG. 4 is a block diagram of a signal processing circuit. FIG. 5 is a block diagram of the comparison operation circuit, FIG. 6 is a diagram showing the correspondence of the print density data to the 4 × 4 print dot matrix, and FIGS. 7 to 10 show examples of printing of the 4 × 4 print dot matrix. FIG. 11 is a diagram showing an output example of the dot pattern memory, and FIG.
FIG. 13 and FIG. 13 are diagrams showing an example of the output of the sensor. 1 is a green LED, 2 is a red LED, 3 is a document, 4 is a short focus lens array, 5 is an image sensor, 31 is an A / D converter, 3
3 is a comparison operation circuit, 34 and 35 are RAM, 36 is a printer, 41 is RO
M and 42 are selectors, and 43 is a control circuit.

Claims (2)

(57) [Claims] 1. An image forming apparatus comprising: reading means for obtaining a reading signal photoelectrically for each pixel of a color original; and image forming means for forming an image using two recording materials based on the signal obtained by the reading means. An achromatic signal generation unit that generates an achromatic signal based on a signal obtained for each pixel by the reading unit; and an achromatic signal generation unit that generates a chromatic signal based on a signal obtained for each pixel by the reading unit. A chromatic color generating unit; a first recording material that reproduces the achromatic color for one pixel based on the achromatic signal and the chromatic signal indicating the same pixel;
Recording means for recording on a recording medium using both of the second recording agent for reproducing the chromatic color. 2. The image forming apparatus according to claim 1, wherein said chromatic color generation means generates said chromatic color signal based on a ratio of a chromatic color to a density.