JPH10322549A - Image printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily discriminate an original image and a print image when printing and compositing the original image and the print image on recording paper. SOLUTION: A timing control part 18 magnifies the print image by performing the write/read of FIFO memories 17a and 17b based on a designated magnification set to a magngification control part 20, and a density converting part 21 converts the density of print images read out of the FIFO memories 17a and 17b. Besides, the density converting part 21 can select one of plural density conversion patterns in various matrix sizes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image printing apparatus for reading a print image stored in an image memory, synthesizing the read image with a document image, and performing printing.

[0002]

2. Description of the Related Art Generally, by reading a print image stored in an image memory and synthesizing the read image with an original image, the original image and the print image can be synthesized and printed on recording paper.

[0003]

However, if the original image and the print image are simply synthesized and printed on the recording paper, it may be difficult to distinguish the original image from the print image, or the original image may be discriminated. There is a problem that an impossible case occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides an image printing apparatus which can easily distinguish an original image and a printed image when the original image and the printed image are combined and printed on recording paper. With the goal.

[0005]

According to a first aspect of the present invention, an image memory for storing binary print image data and a print image data read from the image memory are stored in a line. A line memory for storing the print image data stored in the line memory, scaling means for scaling the print image data stored in the line memory in accordance with a specified magnification, and density for converting the density of the print image data scaled by the scale means Conversion means, wherein the density conversion means can select one of a plurality of density conversion patterns having different matrix sizes.

A second means is that in the first means, the density conversion means can select one of a plurality of density conversion patterns having different density steps for converting the density of print image data and different matrix sizes. It is characterized by.

The third means includes a first path for transferring the print image data, which has been scaled by the scaling means in the first and second means, to the density conversion means; The image processing apparatus further includes a second path for transferring the converted print image data to the scaling unit, and a path switching unit for switching between the first and second paths.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the image printing apparatus according to the present invention, FIG. 2 is an external view showing a digital copying machine to which the image printing apparatus shown in FIG. 1 is applied, and FIG. Side view showing a reading optical system,
FIG. 4 is an explanatory view showing scanning of the digital copying machine of FIG.
7 is a block diagram showing an image synthesizing system including the image printing apparatus shown in FIG. 1 and the digital copying machine shown in FIGS. 2 to 4. FIG. 6 is an explanatory diagram showing an image synthesized by the image synthesizing system shown in FIG. FIG. 8 is an explanatory diagram showing the flow of image data in the image printing apparatus of FIG. 1, FIG. 8 is an explanatory diagram showing the process of the timing control unit of FIG. 1 at the time of double magnification, and FIG. 9 is four times the timing control unit of FIG. FIG. 10 is an explanatory diagram showing processing at the time of enlargement. FIG. 10 is a block diagram showing an example of the density conversion unit in FIG. 1 in detail.
1 is an explanatory diagram showing a matrix size and a density conversion pattern generated by the density conversion unit in FIG. 10, and FIG. 12 is an explanatory diagram showing processing of the density conversion unit in FIG.

FIG. 13 is a block diagram showing another example of the density converter of FIG. 10 in detail, FIG. 14 is an explanatory diagram showing a density conversion pattern of the density converter of FIG. 13, and FIG. FIG. 16 is a block diagram showing a second embodiment, and FIG.
FIG. 14 is a block diagram illustrating a configuration in which the image printing device of No. 5 is applied to the density conversion unit of FIG. 13.

First, an outline of a digital copying machine to which the image printing apparatus of the present embodiment is applied will be described with reference to FIGS. 2 and 3, the original D is set on the original table 1 so that the reading surface faces downward, illuminated by the light source 2, and the reflected light is reflected by the first mirror 3, the second mirror 4, and the third mirror 5. Is sequentially reflected and passes through the lens 6 to CC
It is read by the D line sensor 7. As shown in FIG. 4, the main scanning direction x of the original D is scanned by the CCD line sensor 7 for each of the lines l1, l2, and the sub-scanning direction y is obtained by the relative movement of the original D and the reading optical system shown in FIG. Scanned.

As shown in FIG. 5, such a copying machine generally includes a scanner 101 for reading an original,
The image processing unit 102 includes an image processing unit 102 that processes the original image read by the image processing unit 01 and a printer 104 that prints the original image processed by the image processing unit 102. C shown in FIG.
The image signal read by the CD line sensor 7 is shown in FIG.
Are subjected to A / D conversion and shading correction by a scanner 101 shown in FIG. 5, and then subjected to scaling processing, filter processing, image quality processing, and the like by an image processing unit 102 shown in FIG.

Then, the original image processed by the image processing unit 102 and the print image from the image printing apparatus 100 shown in FIG. 1 are combined by the OR circuit 103 and output to the printer 104, as shown in FIG. For example, a printed image such as “confidential”, “R”, or “sword” can be synthesized on the document image.

Next, an image printing apparatus 100 according to this embodiment will be described with reference to FIG. The image memory 11 stores a print image such as “secret”, “R”, and “sword” shown in FIG. 6 in a bitmap format. The print image is stored in the X counter 12 and the Y counter synchronized with the document reading. The data is read by the counter 13 and the counter control unit 14 in byte units. Here, based on the control of the counter control unit 14, the X counter 12 is reset by the line synchronization signal and outputs an address signal in the main scanning direction by counting up the pixel clock, and the Y counter 13 starts the scanner 101. The address signal in the sub-scanning direction is output by resetting the line synchronization signal and counting up the line synchronization signal.

The print image read out from the image memory 11 in byte units is stored in a shift register (S) as shown in FIG.
R) 15 performs parallel-to-serial conversion and then F
The data is written to the IFO memory 17a or 17b. FI
Each of the FO memories 17a and 17b has a capacity of 1 bit in the main scanning direction of the print image and a switch 19a,
The data is written and read by the toggle operation according to 19b. That is, by writing to one of the FIFO memories 17a and 17b while reading the other, a print image can be output without interruption between lines.

The timing controller 18 controls the clock signals CLK, the write enable signal WE and the read enable signal RE, and the switches 19a and 19 for writing and reading the FIFO memories 17a and 17b.
The selection signal SEL of b is output. In this case, the timing control is performed based on a pixel clock in units of one pixel in the main scanning direction and in accordance with a line synchronization signal in units of one line in the sub-scanning direction so as to synchronize with the main scanning direction and the sub-scanning direction when reading the original. Do it.

At the time of initial setting, a scaling ratio is externally set in the scaling ratio control unit 20, and the timing control unit 18 controls the FIFO memories 17a and 17b based on the designated scaling ratio set in the scaling ratio control unit 20 as follows. Write and read. FIG. 8 shows the writing and reading processing at the time of double magnification. First, the first printing is performed two lines before the target printing start position.
Lines are read from the image memory 11 by the X counter 12 and the Y counter 13 and written into the FIFO memory 17a (W0 in the figure). The reading of the FIFO memory 17a starts from the print start position (R0-1 in the drawing).
By enlarging and interpolating the main scanning direction by holding the data for one pixel by activating only the pixels,
By repeatedly reading the same pixel data twice between two lines, the sub-scanning direction is enlarged and interpolated (R0-
2).

In a section R0-1 shown in the figure, a second line is read from the image memory 1 during reading from the FIFO memory 17a.
1 and write it to the FIFO memory 17b (W1 shown). Reading of the FIFO memory 17b is performed by FIFO
Starting from the next line (R1-1 in the figure) after the reading from the memory 17a is completed, reading to double the main and sub-scanning directions is performed in the same manner (R1-2 in the figure). Also, R
In the section 1-1, the third line is read from the image memory 11 during the reading of the FIFO memory 17b, and
Writing to the memory 17a (W2 in the figure). Therefore, 2
By performing the toggle operation of the two FIFO memories 17a and 17b, it is possible to read out from the image memory 11 without interruption between the lines of the printed image, enlarge the image, and output the image.

FIG. 9 shows the writing and reading processing at the time of quadrupling, and when reading out the FIFO memories 17a and 17b, the read enable signal RE is activated for one pixel every four pixels to hold the data for one pixel. , The main scanning direction is enlarged and interpolated, and the same pixel data is repeatedly read out four times in four lines to enlarge and interpolate in the sub-scanning direction (R0-1 to R0-).
4, R1-1 to R1-4). The FIFO memory 17
The writing of a and 17b is performed every four lines (illustrated W1,
W2).

Next, an example of the density converter 21 will be described with reference to FIGS. In FIG. 10, a 2-bit main scanning counter 31X counts the main scanning direction in units of a pixel clock X (a), and counts a 2-bit count value X.
(C) and X (b), and the 2-bit sub-scanning counter 31Y counts the sub-scanning direction in units of the line synchronization signal Y (a) and counts 2-bit count values Y (c) and Y (c).
(B) is output. The following selector (SELX) 41X counts the count value X based on the main scanning matrix selection signal.
(C), one of X (b) and the pixel clock X (a), and the selector (SELY) 41Y counts Y (c), Y (c) based on the sub-scanning matrix selection signal.
(B) and one of the line synchronization signals Y (a).

The signals selected by the selectors 41X and 41Y are applied as operation clocks of the 2-bit main scanning counter 42X and the 2-bit sub-scanning counter 42Y. The counter 42X counts the operation clock selected by the selector 41X and counts the 2-bit count value X.
[1], X

[0] is output, and the counter 42Y counts the operation clock selected by the selector 41Y and counts 2-bit count values Y [1], Y [1].

[0] is output.

The 2-bit count value X of the counter 42X
[1], X

[0] is applied to the gate 32 and the upper bit Y of the 2-bit count value of the counter 42Y.
[1] is applied to the inverter 33. The inverted output signal of the gate 32 and the output signal of the inverter 33 are applied to an AND gate 34.

Here, FIG. 11A shows that the selector 41X outputs the pixel clock X based on the main scanning matrix selection signal.
3A shows a case where the selector 41Y selects the line synchronization signal Y (a) based on the sub-scanning matrix selection signal, and in this case, the 2-bit counter 42
Since X and 42Y count the pixel clock X (a) and the line synchronization signal Y (a), respectively, the AND gate 34
Then, as shown in FIG. 11A, a density conversion pattern in which 3 × 2 pixels in a matrix size of 4 × 4 pixels are valid is created.

FIG. 11B shows that the selector 41X selects the lower bit X (b) of the 2-bit count value of the counter 31X based on the main scanning matrix selection signal, and the selector 41Y selects the sub-scanning matrix selection signal. , The lower bit Y (b) of the 2-bit count value of the counter 31Y is selected based on
A density conversion pattern in which 6 × 4 pixels in a matrix size of × 8 pixels are valid is created.

FIG. 11C shows a case where the upper bit X (c) in the main scanning direction and the upper bit Y (c) in the sub scanning direction are selected. In this case, a matrix size of 16 × 16 pixels is used. A density conversion pattern in which the middle 12 × 8 pixels are valid is created. Further, by combining the main scanning matrix selection signal and the sub-scanning matrix selection signal, 3
× 2 types of density conversion patterns are created. Here, each of these density conversion patterns is a density conversion step of reducing the density to 3 × 2/4 × 4.

This density conversion pattern corresponds to the gates 35 and 36.
Is ORed with the density conversion ON / OFF signal, so that when the density conversion is ON from the OR gate 36, FIG.
Only the density conversion patterns shown in FIGS. 2A to 2C are output. On the other hand, when the density conversion is OFF, FIGS.
4 × 4 pixels, 8 × 8 pixels, 16 ×
All the pixels in the matrix size of 16 pixels are valid and no density conversion is performed. The output signal of the OR gate 36 is ANDed with the print image signal as shown in FIG. 12B by the AND gate 37. Therefore, when the density conversion is ON, the print image signal is output as shown in FIG. The density is converted and output. According to the density conversion pattern, a print image is output as it is,
The output can be reduced to 3 × 2/4 × 4 in two density conversion steps.

Next, another example of the density converter 21 will be described with reference to FIGS.

The density converter 21 'includes two-bit X counters 31X and 42X and two-bit Y counters 31Y and 31Y.
Y and the selectors 41X and 41Y have the same configuration. Then, as shown in FIG.
Thin density conversion pattern N in which 2 × 1 pixels are effective
1 and the gate 42, as shown in FIG.
The density conversion pattern N2, which is slightly lighter, in which 2 × 2 pixels out of the four pixels are effective, and the gates 43, 44, and 46,
As shown in (c), a slightly darker density conversion pattern N3 in which 3 × 2 pixels out of 4 × 4 pixels are effective, and gates 44, 4
As shown in FIG. 14 (d), the dark density conversion pattern N4 in which 3 × 3 pixels out of 4 × 4 pixels are effective is generated by 5 and 47.

The selector 48 is configured to select one of the five types of density conversion pattern N0 of the voltage V (ie, all 4 × 4 pixels are valid) and the above-described patterns N1 to N4 based on the density selection signal. The AND gate 37 ANDs the density conversion pattern N selected by the selector 48 and the print image signal. According to such a configuration, 3 × 2 × 5 = 30 types of density conversion patterns are created.

Next, an image printing apparatus according to a second embodiment will be described with reference to FIG. In the first embodiment shown in FIG. 1, the print image signal after the scaling process is
In the second embodiment shown in FIG. 15, the print image signal before the scaling process is further applied from the shift register 15 to the density conversion unit 21, and the order of the scaling process → the density conversion is changed. And density conversion → magnification processing in this order.

However, when the operation is performed in the order of density conversion → magnification processing, the image signal processed by the density conversion unit 21 is input to the FIFOs 17a and 17b to be scaled, and then passed through the density conversion unit 21. Output. When the operation is performed in the order of the scaling process and the density conversion, the shift register 1
5 passes through the density conversion unit 21 and
The data is input to the I / Fs 17a and 17b and scaled, and then subjected to density conversion by the density converter 21 and output.

FIG. 16 shows a circuit in which the second embodiment is applied to the density conversion section 21 'shown in FIG. 13, and a path switching section 50 for switching the path of the print image signal is added. When the operation is performed in the order of density conversion → magnification processing, the print image signal before the magnification processing from the shift register 15 passes the density conversion path (N) or returns to the magnification processing unit (R). Can be selected, and a path (N) for performing density conversion or a path (O) for outputting to the outside can be selected for the print image signal after the scaling process. For the print image signal (output signal of the AND gate 37) after the density conversion, a path (R) for returning to the scaling processing section or a path (O) for outputting to the outside can be selected.

According to the configuration shown in FIG. 16, the density conversion section 21 'shown in FIG. 13 can create 30 density conversion patterns and enlarge the print image after the density conversion. Can be expanded, and
Density conversion other than the density conversion pattern to be created can be performed. Also, performing density conversion with the same matrix size before enlargement can perform density conversion over a wide range, rather than performing density conversion on the image after enlargement with only a certain matrix size.

[0033]

As described above, according to the first aspect of the present invention, the print image can be scaled and the density conversion can be performed using one of a plurality of density conversion patterns having different matrix sizes. When the original image and the print image are combined and printed on the recording paper, the original image and the print image can be easily distinguished.

According to the second aspect of the invention, one of a plurality of density conversion patterns having different density steps for converting the density of the print image data and different matrix sizes can be selected, so that the original image and the original image can be printed on the recording paper. When printing a combined print image, the original image and the print image can be more easily distinguished.

According to the third aspect of the present invention, it is possible to switch between the first pass for converting the density of the scaled print image data and the second path for scaling the density of the converted print image data. Therefore, the original image and the print image can be distinguished within a range equal to or larger than the matrix size of the density conversion pattern.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of an image printing apparatus according to the present invention.

FIG. 2 is an external view showing a digital copying machine to which the image printing apparatus of FIG. 1 is applied.

FIG. 3 is a side view showing a reading optical system of the digital copying machine of FIG. 1;

FIG. 4 is an explanatory diagram showing scanning of the digital copying machine in FIG. 1;

FIG. 5 is a block diagram showing an image synthesizing system including the image printing apparatus shown in FIG. 1 and the digital copying machine shown in FIGS.

FIG. 6 is an explanatory diagram showing an image synthesized by the image synthesis system of FIG. 5;

FIG. 7 is an explanatory diagram showing a flow of image data in the image printing apparatus of FIG. 1;

FIG. 8 is an explanatory diagram showing a process of the timing control unit of FIG. 1 at the time of double magnification.

FIG. 9 is an explanatory diagram showing a process of the timing control unit of FIG. 1 at the time of quadruple magnification.

FIG. 10 is a block diagram showing an example of a density converter of FIG. 1 in detail.

11 is an explanatory diagram illustrating a matrix size and a density conversion pattern generated by the density conversion unit in FIG. 10;

FIG. 12 is an explanatory diagram showing processing of a density conversion unit in FIG. 10;

FIG. 13 is a block diagram showing another example of the density converter of FIG. 10 in detail.

14 is an explanatory diagram illustrating a density conversion pattern of a density conversion unit in FIG.

FIG. 15 is a block diagram illustrating a second embodiment of the image printing apparatus.

16 is a block diagram showing a configuration in which the image printing apparatus of FIG. 15 is applied to the density conversion unit of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Image memory 12 X counter 13 Y counter 17a, 17b FIFO memory 18 Timing control unit 20 Variable magnification control unit 21 Density conversion unit 31X, 42X 2-bit main scanning counter 31Y, 42Y 2-bit sub-scanning counter 33-37, 41-47 Gate 41X, 41Y, 48 Selector

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G06T 1/00 G06F 15/66 450

Claims (3)

[Claims] An image memory for storing binary print image data; a line memory for storing print image data read from the image memory in line units; and a print image stored in the line memory. A magnification unit that scales the data in accordance with a designated magnification; and a density conversion unit that converts the density of the print image data scaled by the magnification unit, wherein the density conversion unit has a plurality of different matrix sizes. An image printing apparatus characterized in that one of the density conversion patterns can be selected. 2. The density conversion unit according to claim 1, wherein one of a plurality of density conversion patterns having different density steps for converting the density of the print image data and different matrix sizes can be selected. Image printing device. 3. A first path for transferring print image data scaled by said scaling means to said density conversion means, and print image data whose density has been converted by said density conversion means to said scaling means. 3. The image printing apparatus according to claim 1, further comprising a second path for transferring, and a path switching unit for switching between the first and second paths.