JPH057804Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a digital copying machine, and particularly to an image processing device thereof.

[Conventional technology]

In a digital copying machine, an image of a document is once converted into an image signal by an image sensor, etc., and then stored in a memory, and the image signal is used to drive a laser printer or the like to perform copying. At this time, by performing various processes on the image signal, it is possible to perform image processing and processing such as enlargement, reduction, movement, trimming, and masking of the original image.

In such a digital copying machine, in order to enhance the visual effect, there are cases where it is desired to insert a mesh pattern into the black portions of characters or the like of the document or the white portions of the background.
In such cases, conventional digital copying machines first read the original with written text and store it in memory, then read the original with the mesh pattern printed on it, and then combine the image data obtained from both originals. A desired output image was obtained by performing predetermined logical operations between the two.

[Problem that the invention attempts to solve]

However, the above-described method requires a large capacity memory to be provided within the digital copying machine, resulting in high costs. In addition, it was time-consuming because two types of originals had to be read.

The present invention was devised to solve the above-mentioned problems, and has a function of changing the image part of the document into a mesh pattern and generating a mesh pattern in the background part using a simple configuration. The purpose is to realize this.

[Means for solving problems]

In order to achieve the above object, the digital copying machine of the present invention performs main scanning in a line by reading an image of a document pixel by pixel in synchronization with a clock signal, and also performs main scanning in synchronization with a line signal. A device that performs sub-scanning by moving in a direction perpendicular to the main scanning direction to obtain document input image data; a first setting means for holding the set information; and a first setting means for inputting a number of clock signals corresponding to the line pitch information in the main scanning direction in synchronization with the input of the line signal. a first parallel line pattern signal generating means for outputting period signals of a number of clock signals corresponding to the line width information in the main scanning direction; a second parallel line pattern signal generating means that outputs period signals of the number of clock signals corresponding to the line pitch information in the main scanning direction each time twice the number of clock signals corresponding to the pitch information is input; a second setting means for setting sub-scanning direction line width information and sub-scanning direction line spacing information of a second parallel line pattern perpendicular to the sub-scanning direction, and holding the set information; A third circuit that outputs a period signal of a number of line signals corresponding to the line width information in the sub-scanning direction each time a number of line signals corresponding to the line pitch information in the sub-scanning direction is input.
each time twice the number of line signals corresponding to the line pitch information in the sub-scanning direction is inputted, the period of the line signal of the number corresponding to the line pitch information in the sub-scanning direction is generated. a fourth parallel line pattern signal generating means for outputting a signal; a signal obtained by logically calculating the output of the first parallel line pattern signal generating means and the output of the third parallel line pattern signal generating means; mesh pattern generation means for generating a mesh pattern signal by performing a logical operation on a signal obtained by performing an exclusive OR operation on the output of the second parallel line pattern signal generation means and the output of the fourth parallel line pattern signal generation means; The present invention is characterized in that it includes means for performing a logical operation on the signal from the mesh pattern generating means and the input image data to obtain output image data.

[Effect]

In the present invention, pattern signals having different periods and widths are generated for each direction in both the main scanning and sub-scanning directions in synchronization with the reading of the image of the document in the main scanning and sub-scanning directions.
Then, by performing a logical operation between these pattern signals, a mesh pattern signal tilted with respect to the scanning direction of the input image is created. and,
By performing a predetermined logical operation between the image of the original read at the same time as the image of the original and the mesh pattern signal generated within the copying machine,
Image data in which a slanted mesh pattern is added to the image portion or background portion of the original is obtained. Furthermore, by changing the period and width of the pattern signal, the slope of the mesh pattern and the density when looking at the entire mesh pattern are changed.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained based on embodiments with reference to the drawings.

FIG. 2 shows a schematic block diagram of a digital copying machine according to the present invention.

In the figure, 1 indicates an image scan, in which a document D is irradiated by a document 2, and the reflected light is focused on an image sensor 4 such as a CCD (charge coupled device) or amorphous silicon through a mirror optical system 3. Ru. Then, by moving the mirror optical system 3 with the light source 2 relative to the original D, the image of the original D is scanned and converted into an electrical signal.

A signal from the image scanner 1 is converted into a digital signal by an A/D converter 5 and output as image data. The image data from the A/D converter 5 is supplied to an image processing device 6, the details of which will be described later. In this way, the image of document D is input. The output of the image processing device 6 is supplied to an output printer 7 to obtain a processed copy image.

In this embodiment, the output printer 7 will be described as a combination of a non-impact printer xerography and a laser ROS (raster output scanner), but it can also be applied to inkjet, thermal transfer, or other printing processes.

Inside the output printer 7, there are provided a photoreceptor drum 8 that rotates at a predetermined speed, a laser ROS 9 for exposing and scanning the photoreceptor drum 8, a laser ROS driver 10 for driving the laser ROS 9, and the like.

The laser ROS driver 10 is supplied with processed image data from the image processing device 6, and modulates the laser 11 provided in the laser ROS 9 according to the image data. A laser beam from a laser 11 is manipulated in the axial direction of the photoreceptor drum 8 by a rotating polygon mirror 12, and the surface of the photoreceptor drum 8 is exposed according to the processed image data.

The latent image formed on the photosensitive drum 8 is developed in the same manner as in a normal electrophotographic copying machine, transferred to copy paper, and then fixed, thereby obtaining an image-processed copy image.

In this embodiment, the image processing device 6 processes the image data from the image scanner 1.
Performs processing to add a mesh pattern. Details of this processing will be described later.

In the above example, the image processing device 6 is separated from the image scanner 1 and the laser ROS 9, but this is to make the functions easier to understand, and the image processing device 6 may be included in the image scanner 1. , also laser ROS9 or output printer 7
may also be included.

Next, the image processing device 6 will be explained with reference to FIG.

In the figure, 21 indicates an N-ary counter in the main scanning direction, and the counter 21 is supplied with a line sync 101, which is a synchronization signal for each row, and a video clock 102, which is a synchronization signal for each pixel.
Video clock 1 is synchronized with line sync 101.
Counting the number of 02. Further, a carry 104 is output for each count value N, and the count value is given to a comparator 22. The value of N is given by the main scanning direction line pitch register 25.

The comparator 22 outputs a match signal 105 when the count value of the counter 21 and the value of the main scanning direction line sub-register 26 match.

The flip-flop 23 has a video clock 1.
02, carry 104, and coincidence signal 105 are given, and a pattern signal 106 is output.
The pattern signal 106 goes high in synchronization with the video clock 102 when the match signal 105 goes high, and goes low when the carry signal 104 goes high (see FIG. 3).

The flip-flop 24 has a video clock 1.
02, a match signal 105 is given, and a pattern signal 107 is output. The level of this pattern signal 107 is inverted in synchronization with the video clock 102 when the coincidence signal 105 becomes high level (see FIG. 3).

Also, similar to the main scanning direction N-ary counter 21,
A sub-scanning direction N-ary counter 27 is provided.
The sub-scanning direction N-ary counter 27 is supplied with a page sync 103 and a line sync 101, which are synchronization signals for each original document.
The number of line syncs 101 is counted in synchronization with 03. In addition, the sub-scanning direction N-ary counter 27
outputs a carry 108 for every count value N, and the count value is given to a comparator 28. The value of N is given by the sub-scanning direction line pitch register 31.

Comparator 28 outputs a match signal 109 when the count value of counter 27 and the value of sub-scanning direction line width register 32 match.

The flip-flop 29 has a line sink 10
1, a carry 108, and a coincidence signal 109 are applied, and a pattern signal 110 is output. The same pattern signal 110 becomes high level in synchronization with the line sync 101 when the coincidence signal 109 becomes high level, and becomes low level when the carry signal 108 becomes high level (see FIG. 4).

The flip-flop 30 has a line sink 10
1, a match signal 109 is given, and a pattern signal 111 whose level is inverted in synchronization with the line sync 101 when the match signal 109 changes from high level to low level is output.

In the AND gate 34, the pattern signal 1
06 and pattern signal 110 are taken to obtain pattern signal 112, and in EXOR gate 35, pattern signal 107 and pattern signal 1
The exclusive OR of 11 is taken and the pattern signal 11 is obtained.
It becomes 3. Further, the AND gate 36 performs a logical product of the pattern signal 112 and the pattern signal 113 to obtain a pattern signal 114 for obtaining a target mesh pattern.

Further, in the AND gate 37, the pattern signal 114 and the input image data 115 are logically ANDed to obtain the output image data 116, and the OR
A logical OR is performed at the gate 38 to obtain output image data 117.

Next, the operation will be explained. It is assumed that N of the main scanning direction N-ary counter 21 and the sub-scanning direction N-ary counter 27 is set to "4".

First, the main scanning direction will be explained.

As shown in FIG.
The counter 21 is reset by the low level of the line sync 101, and when the line sync 101 becomes high level, counting starts and operates as a quaternary counter. The carry signal 104 becomes high level when the count value is "3". Main scanning direction line width register 2
If you enter the value "1" in 6, the match signal 10
5 becomes a high level when the count value is "1".
Therefore, video clock 102, carrier 1
04, the flip-flops 23 and 24 receiving the coincidence signal 105 output pattern signals 106 and 107 at the timing shown in FIG. In these pattern signals 106 and 107, if the high level corresponds to black and the low level corresponds to white, then as shown in FIG.
A pattern like b is created. Note that the pulse width x _a of the pattern signal 106 in FIG. 3 corresponds to the main scanning direction line width x _a of the pattern shown in FIG. 5 a,
The pulse width x _b of the pattern signal 107 corresponds to the line pitch X _b of the pattern in the main scanning direction.

In addition, in the sub-scanning direction, as shown in FIG. 4, the counter 27 is reset by the low level of the page sync 103, and when the page sync 103 becomes high level, counting starts and operates as a quaternary counter. are doing. The carry 108 becomes high level when the count value is "3". If a value of "1" is input to the sub-scanning direction line width register 32, the coincidence signal 109 becomes high level when the count value is "1". Therefore,
The flip-flops 29 and 30 receiving the line sync 101, carry 108, and coincidence signal 109 output the pattern signal 11 at the timing shown in FIG.
Outputs 0,111. This pattern signal 11
At 0,111, if the high level corresponds to black and the low level corresponds to white, patterns such as those shown in FIG. 5c and d are created. Note that the pulse width y _a of the pattern signal 110 in FIG. 4 corresponds to the line width _{Y a} in the sub-scanning direction of the pattern shown in FIG. Compatible with Pituchi Y _b .

Therefore, the pattern signal 11 obtained by performing the AND operation of the pattern signal 106 and the pattern signal 110
2 becomes a pattern as shown in FIG. 5e, and the pattern signal 113 obtained by performing the exclusive OR operation of the pattern signal 107 and the pattern signal 111 becomes a pattern as shown in FIG. 5f. Furthermore, the pattern signal 11
2 and the pattern signal 113, the signal 114 has a pattern as shown in FIG. 5g.

Regarding the pattern shown in FIG. 5g, the size and pitch of the halftone dots can be changed by changing the sizes of X _a , X _b , Y _a , and Y _b . As shown in FIG. 1, this is done by changing the values of registers 25, 26, 31, and 32 according to instructions from the CPU (central processing unit) 33, as shown in FIGS. 3 and 4. The generation timings of the carry 104, the coincidence signal 105, the carry 108, and the coincidence signal 109 may be changed so that the coincidence signal 105, the carry 108, and the coincidence signal 109 can be generated.

Suppose now that one of the patterns generated in this manner is as shown in FIG. 6a. Also, consider an input document as shown in FIG. pattern signal 1
14 and the input image data 115, the output image data 116 becomes an output image as shown in FIG. 6c.

In addition, the pattern signal 114 and the input image data 1
Output image data 117 obtained by performing 15 logical sum operations
The output image is as shown in FIG. 6d.

Note that in the above embodiment, the pattern signal 114
Although logical product and logical sum operations were performed between the input image data 115 and the input image data 115, other output images can be obtained by performing other logical operations.

Further, according to this embodiment, by changing the values of the registers 25, 26, 31, and 32 as described above, the size and pitch of the halftone dots of the generated pattern can be freely changed.

[Effect of idea]

As described above, in the present invention, pattern signals with different periods and widths are generated in both the main scanning and sub-scanning directions in synchronization with image reading, and the logic of each pattern signal is By performing the calculation, a mesh pattern inclined with respect to the scanning direction of the input image is generated, and a predetermined logical operation is performed between this mesh pattern and the input image data. Therefore, it is possible to obtain a copy with a visually unnatural slanted mesh pattern added thereto at the same time as reading the original. Furthermore, since the inclination of the mesh pattern and the density when looking at the entire mesh pattern can be changed, the mesh pattern can be easily changed to a pattern according to the user's preference.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an image processing device in a digital copying machine according to the present invention, and FIG.
3 is a timing chart in the main scanning direction for explaining the operation of the circuit shown in FIG. 1, and FIG. 4 is a diagram of the circuit shown in FIG. 1. A timing chart in the sub-scanning direction for explaining the operation, FIGS. 5a to 5g are explanatory diagrams showing a plurality of examples of generation patterns, and FIG. be. 1...Image scanner, 2...Light source, 3...
Mirror optical system, 4... Image sensor, 5...
A/D converter, 6... Image processing device, 7... Output printer, 8... Photosensitive drum, 9... Laser
ROS, 10... Laser ROS driver, 11...
... Laser, 12 ... Rotating polygon mirror, 21 ... Main scanning direction N-ary counter, 22, 28 ... Comparator, 23, 24, 29, 30 ... Flip-flop, 25 ... Main scanning direction line pitch register, 26
...Main scanning direction line width register, 27...N-ary sub-scanning direction counter, 31...Sub-scanning direction line pitch register, 32...Sub-scanning direction line width register, 33
...CPU, D...Manuscript.

Claims (1)

[Claims for Utility Model Registration] Main scanning in a line by reading the image of the original pixel by pixel in synchronization with a clock signal, and moving in a direction perpendicular to the main scanning in synchronization with the line signal. By doing so, a device that performs sub-scanning to obtain document input image data, main-scanning direction line width information and main-scanning direction line pitch information of a first parallel line pattern perpendicular to the main scanning direction are set; , a first setting means for holding the set information, and a first setting means for holding the set information; A first circuit that outputs period signals of a number of clock signals corresponding to the direction line width information.
parallel line pattern signal generating means; and every time twice the number of clock signals corresponding to the line pitch information in the main scanning direction is input in synchronization with the input of the line signal, the line pitch information in the main scanning direction is generated. second parallel line pattern signal generation means for outputting a period signal of a number of clock signals corresponding to the number of clock signals; sub-scanning direction line width information and sub-scanning direction line pitch of a second parallel line pattern perpendicular to the sub-scanning direction; a second setting means for holding the set information; and a second setting means for holding the set information; a third parallel line pattern signal generation means for outputting a period signal of a number of line signals corresponding to the width information; a fourth parallel line pattern signal generating means for outputting a period signal of a number of line signals corresponding to the sub-scanning direction line pitch information; and an output of the first parallel line pattern signal generating means and the third parallel line pattern signal generating means. a signal obtained by performing a logical operation on the output of the line pattern signal generation means; a signal obtained by performing an exclusive OR operation on the output of the second parallel line pattern signal generation means and the output of the fourth parallel line pattern signal generation means; A net-like pattern generating means for generating a net-like pattern signal by performing a logical operation on the net-like pattern signal, and a means for performing a logical operation on the signal from the net-like pattern generating means and the input image data to obtain output image data. Digital copying machine.