JP3155541B2 - Image forming apparatus and control method thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for synthesizing first and second images having a plurality of color components and a control method thereof.

[Prior Art] Conventionally, a color PDL (Page Deletion) is received from a host computer or the like.
The printer that receives the (scription language) data and forms a color image has a controller unit as shown in FIG.
37 and a color printer 11.

As shown in the figure, the color PDL data sent from the host computer 18 via the interface 17 and the external interface 5 is temporarily stored in the PDL data memory 6 and then developed into color image data by the CPU 1. , Are respectively written in the image memories 7-1 to 4-1.

On the other hand, the color printer 11 outputs a plurality of output color components (C: Cy
an, M: Magenta, Y: Yellow, k: Black), is a color printer that performs image formation in a frame-sequential manner.
M, Y, and K are configured to correspond to the respective image memories 7-1 to 4-1. The address generator 9 is configured to control the image memories 7-1 to 4-1 based on the synchronization signal 16-1 from the color printer 11.
Generates a read address from.

Further, in the color printer 11, a memory to be read is selected by the CPU 1 according to which output color component is being formed, and 1 is read from one image memory.
Only one output color component data is sent to the color printer 11, and an image is formed. This is repeated for the four color components to obtain a color image.

Generally, color PDL data mainly targets color characters, figures, illustrations, etc.
Although a high-resolution image memory of pi is required, the gradation is not so necessary.
Is often composed of two values (one bit) for each output color component.

[Problem to be solved by the invention] However, in the above conventional example, color characters, graphics,
Although suitable for printing a binary image of each color such as an illustration, a color copier is used instead of the color printer 11, and an image read by a scanner unit of the color copier and a controller unit 18 are generated. When trying to print with a color PDL image, there was a drawback that it could not be combined well.

That is, as shown in FIG. 3A, the image 32 read by the scanner and the color PDL image 31 (“1” green: C + Y,
“2” black: k, “3” red: M + Y)
In order to obtain 3, the color component images are output sequentially from the controller unit 18 as shown in FIG. 3 (b). Therefore, based on these signals, the color PDL image 31 and the scanned image 32 are read. For example, while forming a magenta component image, the color PDL
Since 36-1 is output as an image, a scanner-read image is output for the portions "1" and "2". Therefore, the part of "1" does not become solid green,
The "2" part is not solid black.

Therefore, such pixel-by-pixel synthesis cannot be performed, and a separate area signal generation circuit is provided, and switching is performed using the area signal, or synthesis is performed so that the color PDL image and the scanned image do not overlap. .

The present invention has been made in view of the above-described problems, and has been made in order to combine first and second images having a plurality of color components.
It is determined whether or not all the color components are present, and when any of the color components is present, the first and second images are prevented from overlapping each other by prioritizing all of the color components, thereby achieving good synthesis. An object is to be able to obtain an image.

[Means for Solving the Problems] In order to achieve the above object, the present invention is an image forming apparatus for synthesizing a first image and a second image having a plurality of color components. First input means for inputting one piece of color component data shown from the scanner unit, and all color component data showing the first image, which is made up of only the same color component data as the one piece of input color component data. A second input unit for inputting data indicating the presence or absence of the first image determined for each pixel, and a pixel determined to have a first image based on the data indicating the presence or absence of the first image , Regardless of the presence or absence of each color component data of the first image,
Synthesizing means for synthesizing each color component by giving priority to each color component data of the first image over each color component data of the second image;
An image forming unit configured to form an image for each color component based on the plurality of color components synthesized by the synthesizing unit.

According to another aspect of the present invention, there is provided a method of controlling an image forming apparatus that controls an image forming apparatus that combines first and second images having a plurality of color components, the method comprising: A first input step of inputting one piece of color component data from the scanner unit, and not only the same color component data as the one piece of input color component data but also all the color component data indicating the first image. A second input step of inputting data indicating the presence or absence of the first image determined for each pixel based on the data, and determining that the first image is present based on the data indicating the presence or absence of the first image Regarding the pixel, regardless of the presence or absence of each color component data of the first image, a synthesis step of synthesizing each color component by giving priority to each color component data of the first image over each color component data of the second image; The plurality synthesized by the synthesizing step And having a supply step of supplying a respective output color components in the image forming apparatus in order to perform image formation on the image forming apparatus for each color component based on the color components.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a block diagram showing a color copying machine compatible with color PDL in the first embodiment.

As shown in the figure, the color PDL data sent from the host computer 18 via the interface 17 and the external interface 5 is temporarily stored in the PDL data memory 6 and then developed into color image data by the CPU 1. , Are respectively written in the image memories 7-1 to 4-1.

On the other hand, the color printer 11 is, for example, a color printer that performs image formation on a plurality of output color components (C, M, Y, k) in a frame-sequential manner.
4 correspond. The address generator 9 generates a read address for each of the image memories 7-1 to 4 based on the synchronization signal 16-1 from the color printer 11.

Each color component image data 13 read according to this read address is selected by the color selector 19 according to which output color component is being formed by the color printer 11, and
Sent to full color scanner / printer 11. Also,
Each color component image data 13 is input to an image presence signal generation circuit 20, where an image presence signal 21 indicating presence or absence of an image is generated for each pixel. The image presence signal generation circuit 20 is a circuit that determines whether each of the input color component signals 13 belongs to a predetermined effective image group or an invalid image group. For example, an invalid image group: each output color If the components are all "0" effective image group: other than that, the image presence signal generation circuit 20 is configured as shown in FIG. 2 (b).

The serial interface 10 is for the serial communication between the full-color scanner / printer 11 and the CPU 1, and the ROM 2 and the RAM 3 store program data and control data to be executed by the CPU 1. Also font
The ROM 4 holds font data for expanding color characters in the PDL data into image data.

FIG. 2A is a schematic block diagram showing the internal configuration of the full-color scanner / printer 11.

As shown in the figure, the image data 14 of each output color component sent from the controller unit 37 is converted from binary to multi-value data 30 by a binary / multi-value conversion unit 24 and input to the selector 25. . On the other hand, the image data 29 of each output color component read by the color scanner unit 23 is also input to the selector 25, and the two output color component signals are switched by the above-mentioned image presence signal 21 and synthesized. Color printer 26
Sent to

The synchronization signal 27 sent from the color printer 26 is sent to the controller unit 37 via the sequence controller 22 and also sent to the color scanner unit 23.

As shown in FIG. 3 (a), a color scanner unit
When the multi-valued scanner read image 32 read at 23 and the image read at the controller 37 are combined in pixel units to obtain a combined image 33, the controller 37 responds to each output color component. Then, the output color component images 36-1 to 36-4 shown in FIG. 3B are read out, and at the same time, FIG.
The signal obtained by calculating the logical sum of the respective color components is read out as the image presence signal 21 as indicated by 36-5 shown in FIG.

FIG. 4A is a timing chart at the time of composite printing.

In the figure, a vertical synchronization signal VSYNC and a horizontal synchronization signal HSY
NC is a part of the synchronization signal 16-1 from the printer 11.
Based on these synchronization signals, each color component image signal 13-1 to 13-1
4 is read out from each of the image memories 7-1 to 4-1 and selected by the color selector 19, and the first output color component signal V
_out1 14 is sent out. At the same time, the image presence signal Vi21 is transmitted from the image presence signal generation circuit 20.

On the other hand, the second image read by the color scanner unit 23
The output color component signal V _out2 29 and the above-mentioned V _out1 14 are switched based on the image presence signal 21 and combined to form an image signal.
V _out3 28 is sent out.

FIG. 4 (b) is a detailed timing chart of the section shown in FIG. 4 (a).

As shown in the figure, _Vout1 and _Vout2 are switched by the image presence signal Vi. For this reason, in addition to the green portion P1 in the PDL image, the scanner read image is also removed from the black portion P2 and the red portion P3, and a clear solid image is obtained.

Next, the processing procedure at the time of composite printing will be described below with reference to the flowchart shown in FIG.

First, at step S101, PDL data is received from the host computer 18 via, for example, the RS-232C interface 17 and the external interface 5, and is stored in the PDL data memory 6. Next, in step S102, the data is developed in the image memories 7-1 to 4-1.

Next, in step S103, the color selector 19 is set so as to select the M component image, and in the following step S104, the color printer 26 is started. And color printer 26
The color scanner 23 is synchronized with the synchronization signals 27 and 16-1 from the
To read the one-color component data from the image memory 7 at the same time, and perform image synthesis and one-color component image formation based on the image presence signal 21. Then, in step S105, it is determined whether the image forming process has been performed for each of the M, C, Y, and k color components, and the above process is repeated for all the color components to form a full-color image.

<Second Embodiment> Next, a second embodiment according to the present invention will be described below with reference to FIGS.

FIG. 7 is a schematic block diagram showing the configuration of the image forming apparatus according to the second embodiment.

The difference from the first embodiment shown in FIG. 1 is that an image presence signal memory 7-5 is provided instead of the image presence signal generation circuit 20, and a read signal from the memory 7-5 is used as an image presence signal. 21. Image memory 7
To -5, the CPU 1 expands the PDL data and expands the image memory 7-
When writing to pixels 1 to 4, the result of determining whether each pixel belongs to an effective pixel group or an invalid image group is written. This embodiment requires an extra memory plane compared to the first embodiment, but has the advantage that halftones can be expressed for each color component image memory by the dither method or the like. However, when the dither method is used, the halftone is represented by the area distribution of "0" and "1". Therefore, when the dither method is used in the first embodiment, a "0" portion is combined with a scanner image.

Therefore, in the second embodiment, for the portion that becomes “0” by the dither method, and for the portion that has an image on the PDL data before expansion, “1” (image is present) is stored in the image presence signal memory 7-5. ), The dither method can be used.

FIG. 8 is a block diagram of the full-color memory / printer 11 of the second embodiment. The difference from the first embodiment is that
The point is that instead of the color scanner unit 23, the read image 42 from the full color image memory 38 and the PDL image 30 are combined.

The full-color image memory 38 includes R (Red), G (Green) .B
(Brue) three-color components, which are lower in resolution than the image memory, but multi-valued (for example, 8 bits) for each color component
It is. The RGB image read from the full-color image memory is converted by an RGB / CMYk conversion circuit 39 into a color printer 26.
Is converted into output color component data corresponding to each color component formed by

As described above, according to the above-described embodiment, when the image from the external host computer is combined with the scanner-read image, the host computer image is extracted from the computer image by extracting the image presence signal from the computer image. It can fit into the scanned image. In particular, in the embodiment, when image formation is performed in a frame-sequential manner, a natural image portion where a computer image is synthesized can be reliably erased, so that a synthesized image with good image quality can be obtained.

The printer includes a color laser beam printer,
A color dot printer, a color ink jet printer or the like can be used.

Further, the computer image is not limited to binary, but may be multi-valued data.

[Effects of the Invention] As described above, according to the present invention, when synthesizing the first and second images having a plurality of color components, it is determined whether or not all the color components are present. When there is a color component, by combining all the color components with priority, it is possible to prevent the first and second images from overlapping, and to obtain a good composite image.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing the configuration of a color image forming apparatus according to the first embodiment, FIG. 2 (a) is a detailed block diagram showing the configuration of a color scanner / printer, and FIG. 2 (b) is an image presence signal. FIG. 3 (a) is a diagram illustrating the configuration of a generation circuit, FIG. 3 (a) is a diagram illustrating image synthesis, FIG. 3 (b) is a diagram illustrating an image of each color component output in a frame-sequential manner, (B) is a timing chart for image synthesis, FIG. 5 is a flowchart showing image synthesis, FIG. 6 is a schematic block diagram showing the configuration of a general color image forming apparatus, and FIG. 7 is a second embodiment. FIG. 8 is a schematic block diagram showing the configuration of a color image forming apparatus, and FIG. 8 is a detailed block diagram showing the configuration of a full-color memory / printer. In the figure, 1 ... CPU, 2 ... ROM, 3 ... RAM, 4 ... Font ROM, 5 ... External interface, 6 ... PDL data memory, 7-1 to 7-4 ... Image memory, 9: an address generator, 10: a serial interface, 11: a full-color scanner / printer, 18: a host computer, 19: a color selector, 20: an image-present signal generation circuit.

Continuation of the front page (56) References JP-A-1-129664 (JP, A) JP-A-63-109059 (JP, A) JP-A-1-184143 (JP, A) JP-A 64-75237 (JP) , A) JP-A-64-68064 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/525 G03G 15/01

Claims (6)

(57) [Claims] 1. An image forming apparatus for synthesizing first and second images having a plurality of color components, wherein a first input for inputting one color component data representing the second image from a scanner unit. Means, and data indicating presence / absence of the first image determined for each pixel based on not only the same color component data as the input one color component data but also all color component data indicating the first image And a second input means for inputting the first image, and for a pixel determined to have the first image based on the data indicating the presence or absence of the first image, regardless of the presence or absence of each color component data of the first image Combining means for combining each color component data of the first image with respect to each color component data of the second image for each color component; and for each color component based on the plurality of color components combined by the combining means. Image forming means for forming an image on An image forming apparatus comprising: 2. The apparatus according to claim 1, wherein said first image is binary for each output color component, and said second image is multi-level for each output color component. Image forming apparatus. 3. The image forming apparatus according to claim 1, wherein said image forming is performed in a frame sequential manner. 4. A method for controlling an image forming apparatus for synthesizing a first image and a second image having a plurality of color components, the method comprising: A first input step of inputting from the scanner unit; and not only the same color component data as the input one color component data, but also a determination made for each pixel based on all color component data indicating the first image. A second input step of inputting data indicating the presence or absence of the first image; and a first image for pixels determined to have a first image based on the data indicating the presence or absence of the first image. Irrespective of the presence / absence of each color component data, a combining step of combining each color component data of the first image with a priority of each color component data of the second image for each color component; Each color component based on the color component Supplying each output color component to the image forming apparatus so as to cause the image forming apparatus to form an image each time the image forming apparatus performs image formation. 5. The apparatus according to claim 4, wherein said first image is binary for each output color component, and said second image is multi-level for each output color component. A method for controlling an image forming apparatus. 6. The method according to claim 4, wherein said supplying step supplies the combined output color components in a frame-sequential manner.