JP2509468B2 - Image processing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus,
In particular, the present invention relates to image processing when the inputted dot pattern information is color printed by a frame sequential color printer.

[0002]

2. Description of the Related Art Devices such as an ink jet printer, a thermal transfer printer, a laser beam printer and the like have been conventionally known. With such a device, it is possible to reproduce a dot pattern such as a character or a specific line pattern in a desired color.
When the dot pattern is reproduced in color, in order to reproduce the color, the color can be generated by synthesizing a desired color component from each color component of Y, M, C and Bk. . In order to reproduce color colors as the image forming method, a conventional apparatus is provided with color component memories corresponding to respective color components (Y, M, C, Bk) required for full color to generate color colors. The dot pattern is stored in a color component memory corresponding to a required color component.

The color printer sequentially prints out the yellow image first, the magenta image second, the cyan image third, and the black image fourth.
Color images are obtained by superimposing the images of the respective colors.

Each time each color component is printed, the dot pattern stored is read from the color component memory corresponding to each color component, and the dot pattern of each color is formed by superimposing the dot pattern on each color component image. .

[0005]

However, in the conventional apparatus, the memory of each color component (color component memory of four colors) is used in order to generate the dot pattern by expanding the code information to generate the dot pattern. However, the circuit scale becomes large and expensive.

Accordingly, an object of the present invention is to provide
Provided is an image processing device for a frame sequential color printer which can reduce the circuit scale, can be inexpensive, and can prevent color fringing to reproduce a dot pattern such as a character or a specific line pattern in a color color. To do.

[0007]

In order to achieve such an object, an image processing apparatus of the present invention scans a recording medium line by line to form an image on the medium, and for each color component of a plurality of color components. An image processing apparatus for a color printer that forms an image sequentially in each frame, and generates dot pattern information input means for inputting dot pattern information and specification information for specifying an image forming color of the dot pattern information. Generating means, storage means for storing the dot pattern information regardless of image formation designated by the designation information, synchronization signal input means synchronized with line-by-line scanning of the color printer, and each color component of the color printer. In order to color the pattern information according to the designation information without changing the frame-sequential image forming sequence, the designation information is designated by the designation information. Corresponding to the image forming operation of the color components constituting the image formation color, at a timing synchronized with the synchronizing signal, and has a reading means for reading out the pattern information stored in said storage means.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an entire embodiment of the present invention. In the illustrated image processing apparatus, the character code string signal as shown in FIG. 2 is used as the character image data 101, and R, G, B as shown in FIG. 3 is used as the color image data.
Color identification signal 104 and vertical and horizontal synchronization signals 106
An image signal 105 accompanied by V and 106H is supplied from the outside. Further, the image trimming position designation signal 102,
103, 107, 108 are also supplied from the outside.

FIG. 2 shows a character image data string signal, which includes the character string data C ₁₀ , C ₁₁ , C ₁₂ ... In the first row following the leading identification code ITOP of one image. Further, the RET code is inserted after the last character of each line. Therefore, the receiving side (that is, the color recording device side)
When the RET code is detected at, a line feed is performed. In FIG. 2, R ₁ is the RET code on the first line, R ₂
Is the RET code on the second line. The end code IEND of the one-character image is inserted next to the last line in the one-character image to end the one-character image data. In this color recording apparatus, the end of one character image is identified by receiving this IEND code.

Character image data 1 supplied as described above
01 is stored in the character code buffer 10 for one screen. At this time, the above-mentioned special code (for example, ITOP code, RET code, IEND code) is decoded by the character code decoder 11, and the storage start / line feed command signal 109 and the storage end signal 110 for storing the character image are transmitted. .

FIG. 4 shows an example of the character screen thus stored. Here, each character A, B, ... A, b,
c, ... Are represented by, for example, an 8-bit ASCII code. Since this color recording apparatus adopts the laser beam method using a dot image, it is necessary to convert the above-mentioned character code string into a dot shape. for that reason,
In the present embodiment, the dot conversion is performed using the character generator 9. Character generator 9
Regarding the above, the description is omitted because it is the same as the known one. At this time, the area information signal 1 indicating which area of the one-character image supplied from the outside should be printed out.
02 (that is, information designating the row and column of the character code image) is given from the external device.

For example, in the character code image shown in FIG. 4, the print start character and end character are (m ₁ ,
When given by n ₁ ) to (m ₂ , n ₂ ), the area within the bold line shown in the figure is read from the character code buffer 10.
Then, in response to the printout designation information (m ₁ , n ₁ ) and (m ₂ , n ₂ ) included in the region information signal 102, the read position designation circuit 17 and the read address generator 18 output the read address of the designated region. appear.

On the other hand, the designation signal 103 designates a region of the print image where the character image region designated as described above should be printed out. The writing area for printout is the pixel number at the writing start position, the scanning line number (m ₁ ′, n ₁ ′),
The write end position is given with the same number (m ₂ ′, n ₂ ′), and the write address to the image memory 8 is generated by the image memory write position designation control circuit 15 and the image memory address generator 14.

The character code image in the specific area thus read out from the character code buffer 10 is converted into dot data by the character generator 9 and stored in a designated area in the image memory 8 to be printed out. . This state is shown in FIGS. 5A and 5B.

Next, the processing of the color halftone image supplied as the density data of each color of R, G and B will be described. As shown in FIG. 3, the color halftone image has R, G, and B color identification signals 104 and vertical and horizontal synchronization signals 106V and 106V.
H and density data (that is, an image signal) 105 for each pixel of the image. Each color image is R,
It is stored in the buffer memories 28-1, 28-2, 28-3 for each color according to the G and B color identification signals 104, respectively.

The synchronizing signals 106V and 106H are supplied to the storage address generator 32, and the address selector 30 supplies necessary addresses to the image buffer memories 28-1, 28-2 and 28-3. Thus, each color image is stored in the image buffer memory 28-1, 28.
It is stored in each of -2 and 28-3.

After that, similarly to the reading from the character code buffer 10, the area 107 for printing out the halftone image is specified by the signal 107 supplied from the outside. This is given with the printout start point, pixel number, and scan line number, and the corresponding image memory 28
Addresses -1, 28-2, 28-3 are generated from the read address generator 31.

At the time of reading, an image buffer memory for yellow (stores a B signal) 28-1 and an image buffer memory for magenta (stores a G signal) 28-1.
28-2, the same pixel from the image buffer memory for cyan (which stores the R signal) 28-3 is Y, M, C respectively.
It is read out simultaneously as a component. The color signal read out in this manner is finally stored in the image memory 21 for halftone images, but the image area designated as described above is printed out at the designated position. As described above, the write start position is designated by the signal 108 supplied from the outside (not shown). In response to this, the image memory write position designation circuit 23 and the image memory address generator 22 generate an address of the image memory 21 corresponding to the designated position. This behavior is
This is similar to the case of the character image data described above.

The image buffer memory 28-1,
The color density data for each pixel read from 28-2 and 28-3 is subjected to gamma conversion (density conversion) in accordance with the characteristics of the image processing apparatus in the gamma correction circuit 27, and further,
After undergoing masking processing (see 26) and UCR processing (see 25), which are well known in the printing art, and then dithering (see 24), a dot is placed at a specific position in the image memory 21 designated as described above. It is stored as data. Here, as is well known, the dither process is an electrical process for determining a print dot to be output by comparing density data for each pixel with a threshold value in order to reproduce a halftone.

The image processing apparatus sequentially prints out the yellow image first, the magenta image second, the cyan image third, and the black image fourth, and superimposes the respective color images. Since a full-color image is obtained, the storage capacity of the image memory 21 is sufficient for one image. Then, each time each color is printed, the above-described color processing and transfer to the image memory 21 are performed.

In order to read out the data from the image memory 8 for character images and the image memory 21 for halftone images and send them to the laser light modulation circuit 5, these image data are stored as dot data in the image memories 8 and 21, respectively. Further, the same address is assigned to the same pixel. In this embodiment, the addressing of both image memories 8 and 21 is controlled by the image memory address generator 14. That is, a read address is generated at the time when an image is stored in both the image memories 8 and 21, so that dot data of a character and a halftone image corresponding to the same pixel is transmitted.

The dot data read from the image memories 8 and 21 are superimposed by the OR gate 8 to modulate the laser light. The modulated laser light is the photosensitive drum 1.
Form an electrostatic latent image on top. The process of creating a print image is similar to that of a normal laser beam printer.
Four types of developing devices (none of which are shown) are selectively used for M, C and B _K (black). Also, signal 11
Reference numeral 3 denotes a horizontal synchronizing signal sent from the laser beam detector 40 when the laser beam is applied to the laser beam detector 40, which synchronously reads out image data from the image memories 8 and 21.

The signal 112 is a signal for controlling the color of the character image, and the data is output from the image memory 8 only when the desired color is printed out. Similarly, when a halftone image is read from the image memory 21, it is possible to control so as to read only a desired color image and obtain an image of a single color or a composite color.

FIG. 5 shows an example in which the designated areas of the character image and the halftone image are individually moved and the two images are combined. That is, the area is moved with respect to each of the input images A and C, and the obtained images B and D are combined to obtain the image B + D.

[0026]

As described above, according to the present invention,
In the frame sequential color printer, reduce the circuit scale,
It is possible to reproduce a dot pattern such as a character or a specific line pattern in a color color at a low cost while preventing color fringing.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an entire embodiment of the present invention.

FIG. 2 is a diagram showing an example of character image data.

FIG. 3 is a diagram showing an example of color image data.

FIG. 4 is a diagram showing an example of a character screen stored in a character code buffer.

FIG. 5 is a diagram showing an example in which designated areas for a character image and a halftone image are moved separately, and both screens are combined.

[Explanation of symbols]

1 Photosensitive Drum 2 Lens 3 Reflecting Mirror 4 Laser Light Source 5 Laser Light Modulating Circuit 6 Line Buffer 7 OR Gate 8 Character Image Memory 9 Character Generator 10 Character Code Buffer 11 Character Code Decoder 12 Interface 14 Image Memory / Address Generator 15 Image Memory Writing Position designation circuit 16 Control circuit 17 Read position designation circuit 18 Read address generator 19 Write address generator 20 Address selector 21 Image memory for halftone image 22 Image memory / address generator 23 Image memory write position designation circuit 24 Dither circuit 25 UCR circuit 26 Masking Circuit 27 Gamma correction circuit 28-1, 28-2, 28-3 Image buffer memory 29 in Interface 30 address selector 31 read address generator 32 write address generator 33 read position designation circuit 101-103 signal

Claims (1)

(57) [Claims] 1. An image processing apparatus for a color printer, which scans a recording medium line by line to form an image on the medium, and image-forms a plurality of color components frame by face for each color component. A dot pattern information input means for inputting dot pattern information, a generating means for generating designation information for designating an image forming color of the dot pattern information, and the dot pattern information for forming an image designated by the designation information. Storage means for storing regardless of the above, a synchronizing signal input means for synchronizing line-by-line scanning of the color printer, and the pattern information to the designation information without changing a frame sequential image forming sequence for each color component of the color printer. Corresponding to the image forming operation of the color components forming the image forming color designated by the designation information, the synchronization signal In synchronized timing, the image processing apparatus characterized by having a reading means for reading out the pattern information stored in said storage means.