JPH0927041A - Image forming device and image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optionally set the rule of an image thinning-out process in toner saving mode. SOLUTION: A line memory(LA) 3 delays input image data SVDO by one line and a line memory(LB) 4 further delays them by one line. Consequently, image data of three lines are obtained. Gate circuits 5 and 6 extract the outline of the input image. A memory 14 is a memory which stores thinned-out data and outputs thinned-out data in an address indicated by a line counter 10 and a dot counter 12. An AND circuit 7 substitutes the output (thinned-out data) of the memory 14 for the painted-out area of black pixels encircled with the outline and outputs the result. A gate circuit 8 composites the outline and the painted-out area image after the thinning-out process and outputs the resulting image. The thinned-out data in the memory 14 are rewritten and then thinned- out data corresponding to characteristics of a printer engine can be outputted (8Q).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an image processing apparatus, and more particularly to an image forming apparatus and an image processing apparatus for thinning an input image.

[0002]

2. Description of the Related Art Conventionally, in a toner saving mode of an electrophotographic printer such as a laser beam printer, pixels in an area filled with black pixels (hereinafter referred to as a solid black portion) are
A method of regularly thinning out is used by using a video clock signal or the like which is a synchronizing signal for image processing, and the thinning rule is fixed.

[0003]

However, in the above-mentioned conventional example, since the number of black pixels (toner amount) is reduced by regularly thinning out solid black pixels (black pixels are white pixels), There is a problem that drawing unevenness depending on the characteristics of the printer engine unit is conspicuous. Further, since the thinning rule is fixed, it is not possible to set the thinning rule according to the characteristic when the characteristics of the printer engine part change with time or when the printer engine part is modified. . Therefore, it is difficult to develop a printer and the like, and it is difficult to develop and manufacture a device that uses the same image processing unit but has different printer engine unit characteristics.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus and an image processing apparatus in which a rule for thinning out pixels in an image painted area can be arbitrarily set. To do.

[0005]

In order to solve the above problems, an image forming apparatus according to the present invention is an image forming apparatus for thinning an input image to form an image, and extracting a painted area from the input image. And a thinning-out data setting means for setting thinning-out data for thinning out the painting-out pixels forming the painting-out area, and thinning-out means for thinning out the painting-out pixels based on the thinning-out data. A visualizing means for visualizing a thinned-out image obtained by thinning out the painted pixels from the input image on a recording medium, wherein a rule for thinning out pixels in the painted area of the input image is arbitrary. Can be set to.

According to a preferred embodiment of the present invention, for example, the thinned-out data setting means is preferably capable of rewriting the thinned-out data. For example, the thinned-out data is appropriately set according to the characteristics of the visible image forming means. It becomes possible to rewrite, streamline product development, etc., and cope with changes with time of the visual imaging means. Further, for example, the thinned-out data may be pattern data that replaces the filled area.

Further, for example, the thinning-out data may be data which gives the cycle for thinning out the painted area in a predetermined cycle. Further, for example, further comprising a contour extracting means for extracting a contour line of the painted area, the thinning means, by thinning out the painted pixels of the area other than the contour line in the painted area, The outline of the crushed area can be emphasized.

Further, for example, the input image may be a black and white binary image, and the filled area may be a black pixel area. Further, for example, it further has a mode switching means for switching between the first mode and the second mode, and the visible image forming means inputs the thinned-out image in the first mode, and the input in the second mode. The image may be visualized.

Further, for example, a visible image may be formed by an electrophotographic method.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A preferred first embodiment of the present invention will be described below with reference to the drawings. FIG. 11 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. The image input unit 1001 is, for example, an image input unit such as a host computer or an image scanner which is an external device, and the form of the input image does not matter. The image data generation / processing unit 1002 generates image data based on the input image, and performs processing such as smoothing processing and edge enhancement as necessary.

The thinning unit 1003 is a block for thinning pixels in solid black portions in the toner saving mode, and the thinning rule can be changed according to the characteristics of the printer engine 1005. The toner mode switching unit 1004 is
In the toner-saving mode, the image switching in which the black solid portion is thinned by the thinning unit 1003 is selected, and in the normal mode, the image data supplied from the image data generation / processing unit 1002 is selected and supplied to the printer engine 1005. It is a department.

The printer engine 1005 is an image forming section for forming a visible image on a recording medium by an electrophotographic system such as a laser beam printer. The characteristics of the printer engine 1005 differ depending on each device as described above, and it can be said that it is difficult to obtain a data thinning rule suitable for any printer engine. Therefore, making the data thinning rule changeable as in the thinning unit 1003 according to the present embodiment is, for example, 100
It becomes possible to modify the data thinning function by adapting it to various printer engines after manufacturing the device consisting of 1 to 1004, which is advantageous in product development and the like.

Further, even after the product is completed, for example, after it has been distributed in the market, it is possible to change the data thinning function according to the change in the characteristics of the printer engine unit with time, the user's preference, or the like. Hereinafter, the thinning unit 1003
Will be described in detail. FIG. 1 is a diagram showing a configuration of a thinning unit 1003 according to this embodiment.

In FIG. 1, the SVDO signal 2 is a video signal supplied from the image data generating / processing unit 1002. LA3 is a line memory for delaying the SVDO signal 2 by one line, and LB4 is a line memory for delaying the output 3O of the LA3 by one line. L
Image data for three lines can be obtained by A3 and LA4.

The VSYNC_ signal 9 is a sync signal (negative logic), BD_, supplied for each page from a control unit (not shown).
Similarly, the signal 11 is a synchronization signal (negative logic) supplied line by line from a control unit (not shown), the VCLK signal 13 is a video clock for image processing, and the SDVO signal 2 is synchronized with this signal. Supplied. The line counter 10
The number of lines is counted in synchronization with the BD_ signal 11, and VS
A counter that is cleared by the YNC_ signal 9.
The dot counter 12 is a counter that counts the number of dots in a line in synchronization with the VCLK signal 13 and is cleared by the BD_ signal 11.

The memory 14 stores the toner in the toner saving mode.
This is a memory that stores a rule (pattern for replacing solid black portions) for thinning out solid black portion data (black pixels), and the contents can be rewritten to arbitrary data. The gate circuits 5 to 8 emphasize the contour line of the image forming the main scanning direction,
With respect to the solid black portion, control is performed to output thinned data stored in advance in the memory 14.

The operation of the thinning section 1003 will be described below. FIG. 3A shows an example of image data before thinning processing. Lines 1, 2, 9, 10, and 11 are white pixel regions, and shaded lines 3 to 8 are black pixel regions. is there. FIG. 2 shows a thinning unit 1 when the image shown in FIG. 3A is supplied from the image data processing unit 1002.
It is a figure which shows the signal of 003 typically.

In FIG. 2, SVDO signal 2 is shown on line 3
8 is a black pixel, the output signal 3O of LA3 is delayed by one line, and the output signal 4O of LA4 is 3
It is delayed one line from O. Further, the output of the EOR circuit 5 which receives the signal 2 and the signal 40 becomes like the signal 5O in FIG. AND with signals 5O and 3O as inputs
The output of the circuit 6 looks like the signal 6O in FIG.

The signal 5O is "Low", and the signal 3Q is "Low".
When it is "High", the AND circuit 7 outputs the thinned-out data stored in advance in the memory 14. Therefore, AN
The output 7O of the D circuit 7 becomes like the signal 7O of FIG.
The output of the OR circuit 8 which receives the signals 6O and 7O is as shown in FIG.
Signal 8O. That is, in the output signal (8O) of the thinning unit 1003, the contour line (main scanning direction) of the image becomes a black pixel, and the solid black portion sandwiched by the black pixels is replaced by the thinning data.

FIG. 3B shows an example of thinned data, which is 4 lines (specified by addresses A4 and A3).
It is thinning data composed of × 8 dots (specified by addresses A2 to A0). In this case, the thinned-out data forms a repeating pattern in units of 4 lines × 8 dots. The thinned-out data can be rewritten to desired data as described above, and the rewriting operation is controlled by the control unit (not shown).

FIG. 3C shows the image data after the thinning process in which the thinning data shown in FIG. 3B is applied to the image data shown in FIG. [Second Embodiment] In the first embodiment, an example in which only the contour line of the image forming the main scanning direction is emphasized has been described, but the present embodiment describes the contour line of the image forming the sub-scanning direction. An example is also emphasized. The present embodiment can be realized by changing the configuration of the thinning unit 1003 in the first embodiment as follows.

FIG. 4 shows a thinning section 100 according to this embodiment.
It is a figure which shows the structure of 3. The parts having the same functions as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The gate circuits 5, 20, 21, and 28 use the SVDO signals 2, 3O, and 40 to compare adjacent pixels in the sub-scanning direction as in the first embodiment to emphasize and thin the contour line. Circuit. The gate circuits 22 to 27 are circuits for comparing adjacent pixels in the main scanning direction and emphasizing and thinning out contour lines.

The thinning section 1003 according to this embodiment will be described below.
Will be described. FIG. 6A shows an example of image data before thinning processing. In addition, (b) of the figure
Shows an example of thinned-out data stored in the memory 14. (C) of the same figure has shown the image data which applied (b) and thinned out the solid black part of the image data shown in (a).

FIG. 5 is a diagram schematically showing the operation of the thinning unit 1003 when the image data shown in FIG. 6A is supplied from the image data generating / processing unit 1002.
First, the signal 210 is in the state shown in FIG.
(When processing line 4 in (a)). Signal 2
1O is delayed by the D-type FF circuit 22 for one pixel period (2
2O), and the D-type FF circuit 23 further delays by one pixel period (23O). E with signals 21O and 23O as input
The output of the OR circuit 24 becomes as shown by the signal 24O in FIG. AND circuit 25 which inputs signals 24O and 22O
Is output as shown by the signal 25O in FIG. 5, and the contour line forming the sub-scanning direction is extracted from the image data (SVDO signal). The signal 14O in FIG. 5 is thinning data supplied from the memory 14. The AND circuit 26 is a gate circuit for replacing the solid black portion with the thinned-out data, and the signal 25O is "low" and the signal 22O is "high".
When h "(solid black portion), the replacement data is output (2
6O). The OR circuit 27 outputs signals 25O (contour) and 26O.
(Thinned data in which the solid black portion is replaced) is input and a signal 27O is output. The OR circuit 28 outputs signals 20O and 27.
With O as an input, a complete contour line including the main scanning direction and the sub-scanning direction is emphasized, and data obtained by thinning out solid black portions surrounded by the contour line is output.

[Third Embodiment] In this embodiment, the thinning-out data supply unit 400 in the second embodiment is replaced with another circuit, and the outline enhancement and the outline enhancement similar to those in the second embodiment are performed. It is possible to realize thinning of the solid black portion. FIG. 7 is a diagram showing the configuration of the thinning unit 1003 according to this embodiment. It should be noted that parts having the same functions as those in the second embodiment are designated by the same reference numerals and the description thereof will be omitted (in the present embodiment, the OR in the second embodiment is used).
The circuits 27 and 28 are collectively referred to as an OR circuit 28 ').

The operation of the thinned-out data supply unit 700 will be described below. When writing the thinned-out data, the thinned-out data of the odd lines is supplied to D7 to D4, the thinned-out data of the even lines is supplied to D3 to D0, and the WR signal 35 (gate signal G of the latch circuit 34) is supplied (write pulse is supplied). Supply the thinned-out data to the latch circuit 34.
Latch. After that, when the LD_ signal 32 (negative logic) is supplied, the thinned-out data of the odd lines is stored in the shift register 36 and the thinned-out data of the even lines is stored in the shift register 3.
7 is held.

The thinned-out data held in the shift registers 36 and 37 is shifted in synchronization with the VCLK signal 13 (the data reaching the final stage of the shift register is input to the initial stage of the shift register via the serial input terminal). )
And the thinned-out data that has undergone parallel / serial conversion is Q
It is output from the terminals (36O, 37O). The D-type FF circuit 31 is used as a line selection signal generation circuit. It is cleared by VSYNC_ signal 9 for each page and BD_
The Q terminal (output signal 31Q) is inverted in synchronization with the signal 11, and is "High" for odd lines and "L" for even lines.
ow ”. The gate circuits 38 to 40 function as a multiplexer having the signals 36O and 37O as inputs,
Signal 36O on odd lines, signal 37 on even lines
Output O (40O). Accordingly, it is possible to realize thinning of the solid black portion similar to that of the second embodiment.

Note that the latch circuit 34 does not need to be particularly provided if the configuration is such that the thinned data can be appropriately supplied to the shift registers 36 and 37 by controlling the timing of the LD_ signal 32 and the data signal 33, for example. Absent. [Fourth Embodiment] In the present embodiment, the supply unit of the thinned-out data in the above embodiment is replaced with another circuit. FIG. 8 is a diagram showing the configuration of the thinning unit 1003 according to this embodiment. The parts having the same functions as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The operation of the thinned-out data supply unit 800 will be described below. First, the thinned-out data of odd-numbered lines and even-numbered lines (in the present embodiment, unlike the above-described embodiment, the thinned-out data itself does not replace the solid black portion) is latched by the latch circuit 34 and output to the selector 41. . The selector 41 uses the line selection signal generator 31 to select either thinned-out data of odd lines or thinned-out data of even lines, and supplies the selected data to the Q3 to Q0 terminals of the comparator 42.

The dot counter 12 is BD_for each line.
It is a counter that is cleared by the signal 11 and counts up by the VCLK signal 13, and supplies the count value (Q3 to Q0) to the P3 to P0 terminals of the comparator 42. The comparator 42 has a P input (P3 to P0)
And Q input (Q3 to Q0) becomes equal, output (42O)
To "high". At this time, the black pixels in the solid black portion are output (28O), and when the signal 42O is "low", the solid black portion is thinned out (to be a white pixel).

[Fifth Embodiment] In this embodiment, the thinned-out data supply unit of the above embodiment is replaced with another circuit. FIG. 9 shows the thinning unit 1 according to the present embodiment.
It is a figure which shows the structure of 003. The parts having the same functions as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The operation of the thinned-out data supply unit 900 will be described below. The thinned-out data of the odd-numbered lines or the even-numbered lines is selected by the selector 41 and loaded into the dot counter 43 for each line (BD_ signal 11 is "l".
The dot counter 43 counts up in synchronization with the VCLK signal 13 and the black pixel in the solid black portion is output (28O) only when the RCO terminal (ripple carry out output) becomes “high”. ), "Lo
When w ", solid black portions are thinned out (white pixels).

[Sixth Embodiment] This embodiment has a configuration in which the dot counter 43 in the fifth embodiment is replaced by a shift register 36, and has the same function as that of the third embodiment. FIG. 10 is a diagram showing the configuration of the thinning unit 1003 according to this embodiment. The parts having the same functions as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The operation of the thinned-out data supply unit 1000 will be described below. The thinned-out data output from the selector 41 is subjected to parallel / serial conversion by the shift register 36 and output from the Q terminal (36O). As a result, the solid black portion is replaced with the thinned data. In the above description, the black-and-white image forming apparatus has been described, but the present invention is also applicable to a color image forming apparatus.

Further, in the above description, the electrophotographic image forming apparatus has been described, but the present invention is applicable to the case of saving the raw material for image formation such as ink in the ink ejecting type image forming apparatus. Is also widely applicable. Further, it should be understood that the application range of the present invention is not limited to the above-described reduction of the raw material for image formation but also broadly applies to the technology that requires the thinning of the image.

The present invention also provides a "host computer,
The invention may be applied to a system including a plurality of devices such as an interface and a printer, or to an apparatus including one device such as a copying machine. Further, it goes without saying that the present invention can be applied to the case where it is implemented by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to the system or device, the system or device operates in a predetermined manner.

[0037]

As described above, according to the present invention, it is possible to arbitrarily set a rule for thinning out pixels in a filled area such as a solid black portion according to the image quality of an output image. Become.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a thinning unit according to a first embodiment.

FIG. 2 is a diagram schematically showing signals of a thinning unit according to the first embodiment.

FIG. 3 is a diagram schematically showing an example of images before and after thinning processing according to the first embodiment.

FIG. 4 is a diagram showing a configuration of a thinning unit according to a second embodiment.

FIG. 5 is a diagram schematically showing signals of a thinning unit according to the second embodiment.

FIG. 6 is a diagram schematically illustrating an example of images before and after the thinning process according to the second embodiment.

FIG. 7 is a diagram showing a configuration of a thinning unit according to a third embodiment.

FIG. 8 is a diagram showing a configuration of a thinning unit according to a fourth embodiment.

FIG. 9 is a diagram showing a configuration of a thinning unit according to a fifth embodiment.

FIG. 10 is a diagram showing a configuration of a thinning unit according to a sixth embodiment.

FIG. 11 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the invention.

[Explanation of symbols]

 3,4 line memory 36,37 shift register

Claims (14)

[Claims] 1. An image forming apparatus for thinning an input image to form an image, wherein a filled area extracting unit extracts a filled area from the input image, and thins a filled pixel forming the filled area. Thinning data setting means for setting thinning data, thinning means for thinning the filled pixels based on the thinning data, and a thinned image obtained by thinning the filled pixels from the input image on a recording medium as a visible image. An image forming apparatus, comprising: 2. The thinned-out data setting means can rewrite the thinned-out data.
The image forming apparatus as described in the above. 3. The image forming apparatus according to claim 2, wherein the thinning data is pattern data that replaces the filled area. 4. The image forming apparatus according to claim 2, wherein the thinning-out data is data that gives the period for thinning out the painted area at a predetermined period. 5. The apparatus further comprises a contour extracting means for extracting a contour line of the painted area, wherein the thinning means thins the painted pixels of the area other than the contour line in the painted area. The image forming apparatus according to any one of claims 1 to 4. 6. The image forming apparatus according to claim 1, wherein the input image is a monochrome binary image, and the filled area is a black pixel area. 7. A mode switching means for switching between a first mode and a second mode is further provided, wherein the visible image forming means outputs the thinned image in the first mode, and the visible image in the second mode. 7. The image forming apparatus according to claim 1, wherein the input image is visualized. 8. The image forming apparatus according to claim 7, wherein the visible image forming unit forms a visible image by an electrophotographic method. 9. An image processing device for thinning out an input image, comprising: a filled area extracting means for extracting a filled area from the input image; and a thinning for thinning out filled pixels forming the filled area. An image processing apparatus comprising: a thinning data setting unit that sets data; and a thinning unit that thins the filled pixels based on the thinning data. 10. The image processing apparatus according to claim 9, wherein the thinned-out data setting unit can rewrite the thinned-out data. 11. The image processing apparatus according to claim 10, wherein the thinning data is pattern data that replaces the filled area. 12. The image processing apparatus according to claim 10, wherein the thinning-out data is data that gives the period for thinning out the painted area at a predetermined period. 13. The image forming apparatus further comprises contour extracting means for extracting a contour line of the filled area, wherein the thinning means thins out the filled pixels in the area other than the contour line in the filled area. The image processing device according to claim 9. 14. The input image is a black and white binary image,
14. The image processing apparatus according to claim 9, wherein the filled area is a black pixel area.