JPH05221027A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To print out clearly in a relatively short time an image with which letters are mixed. CONSTITUTION:A controller 11 in an image forming apparatus judges the image data sent from an image making device to be an image data or a letter code. When the data is an image data, it is stored in the first page memory 21, and if the data is a letter code, the data, after being developed on a bit map by a letter generation part 13, is stored in the second page memory 22. Then, a dot pattern on the periphery of a marked picture element of the image data, which is stored in the first page memory 21, is referred to an extension treatment part 23, and the extended pattern for the marked picture element is determined accordingly for the extension treatment of the image data. The data is stored in addition to the bit map data of letters which is stored in the second page memory 22. The stored image data is sent to an image output part 4 for printout.

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 such as a laser printer, and more particularly to a technique for improving resolution by enlarging image data sent from an image forming apparatus such as a personal computer.

[0002]

2. Description of the Related Art Conventionally, when an image formed by an image forming apparatus such as a personal computer is printed out by an image forming apparatus such as a laser printer, the image data sent from the image forming apparatus is independent of the resolution of the image forming apparatus. The resolution is determined to be a predetermined value, and characters are sent as a code and are developed into a bitmap inside the image forming apparatus, so that the resolution differs depending on the resolution of the image forming apparatus. For this reason, in most cases, the image data and the character data have different resolutions, and therefore the image data is usually scaled by software to the same resolution as the character.

For example, FIG. 11 shows a process for printing out an image in which images and characters are mixed at a resolution of 320 dpi.
12 will be described with reference to FIGS. 12A and 12B in the image processing unit 3, in which characters are codes and images are transferred as bitmap data of 160 dpi, for example, from the image creating apparatus 1 shown in FIG. 11 to the image forming apparatus 2. Control unit (CPU)
11 determines whether the image data sent via the receiving unit 12 is a character code or image data.

If the image data from the image creating apparatus 1 is a character code, the character generator 13 outputs 320 dp.
It is expanded into a bitmap for i and stored in the page memory 14, and if it is image data, it is converted from 160 dpi to 3
The image data is enlarged to 20 dpi and stored in the page memory 14, and when one page of image data is stored in the page memory 14, the image data is sent to the image output unit 4 to be printed out.

[0005]

However, in such a conventional image forming apparatus, the CPU as described above is used.
The simple enlargement due to requires a lot of processing time, and there is a problem that the jagged edges of the image become noticeable. The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to print out an image in which an image and characters are mixed relatively quickly and neatly.

[0006]

In order to achieve the above object, the present invention provides an image forming apparatus for processing and outputting image data created by the image creating apparatus, wherein the image data sent from the image creating apparatus. Data discriminating means for discriminating whether the character code is image data or a character code, a first image accumulating means for accumulating the image data, a character generating means for expanding the character code into a bit map, and the means. A second image storage unit for storing the bit map data of the expanded character and a dot pattern around the target pixel of the image data stored in the first image storage unit are referred to and the target pixel is correspondingly referenced. A magnifying processing means for magnifying the image data by determining a magnifying pattern for the And means for accumulating superimposed on the character bit map data stored in the image storage means,
An image output means for outputting the image data accumulated by the means is provided.

Further, a data discriminating means for discriminating whether the image data sent from the image forming apparatus is an image data or a character code, a first image accumulating means for accumulating the image data, and a character. Attention of the character generation means for expanding the code into the bit map, the second image storage means for storing the bit map data of the character expanded by the means, and the image data stored in the first image storage means Refer to the dot pattern around the pixel,
Enlarging processing means for enlarging the image data by determining an enlarging pattern for the pixel of interest accordingly, image data enlarged by the means, and bit map data of characters accumulated in the second image accumulating means. There is also provided an image forming apparatus provided with a means for synthesizing in real time and an image output means for outputting the image data synthesized by the means.

Further, the data discriminating means for discriminating whether the image data sent from the image forming apparatus is the image data or the character code, and the dot pattern around the pixel of interest of the image data are referred to, and in accordance therewith. , An enlarging processing means for enlarging the image data by determining an enlarging pattern for the pixel of interest, a character generating means for expanding a character code into a bit map, an image accumulating means for accumulating the image data, and an image creating apparatus. When the image data sent from the image data is determined to be image data by the data determination means, the image data is enlarged by the enlargement processing means, and when it is determined to be a character code, the character code A control means for expanding the character generation means by the character generation means and sequentially writing each in the image storage means, Also provides an image forming apparatus provided with an image output means for outputting the image data stored in the image storage means.

[0009]

According to the image forming apparatus of the present invention, it is determined whether the image data sent from the image forming apparatus is image data or a character code. If the image data is image data, the first image storage means is used. If the character code is a character code, the character code is expanded into a bitmap and then stored in the second image storage means. Then, the dot pattern around the pixel of interest of the image data stored in the first image storage unit is referred to, and the enlargement pattern for the pixel of interest is determined in accordance with the dot pattern, thereby enlarging the image data to obtain the second image. The character image bitmap data accumulated in the accumulating means is accumulated and accumulated, and the accumulated image data is output.

In the image forming apparatus according to the second aspect, the process up to the process of enlarging the image data is the same as that of the first aspect, and the enlarged image data and the bit map of the characters stored in the second image storage means. This is combined with the data in real time, and the combined image data is output. In the image forming apparatus according to claim 3, it is determined whether the image data sent from the image forming apparatus is image data or a character code, and if it is image data, it is enlarged in the same manner as above, If it is a character code, it is expanded, and it is sequentially written in the image storage means, and the stored image data is output.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block configuration diagram of an image forming apparatus showing an embodiment of the present invention, and the portions corresponding to those in FIG. 12 are designated by the same reference numerals.

This image forming apparatus corresponds to the image forming apparatus 2 shown in FIG. 11, and includes a control section 11 and a receiving section 1.
2, character generation unit 13, first page memory 21, second page memory 22, enlargement processing unit 23, and image output unit 4
It is composed by. The control unit 11 includes a ROM in which programs are stored and a central processing unit (CP) that controls the operation of each unit according to the programs stored in the ROM.
U), a RAM for temporarily storing various data, and the like, and integrally controls the entire image forming apparatus.

The receiving unit 12 receives image data and character codes sent from an image creating apparatus similar to the image creating apparatus 1 shown in FIG. The character generation unit 13 has bitmap data corresponding to the character code from the image creating device at several kinds of resolutions, and the character code is converted into a bitmap having an optimum resolution according to the resolution of the image output unit 4 and the enlargement or reduction ratio. Perform expansion processing.

The first page memory 21 is for storing image data and the second page memory 22 is for storing character bit map data, respectively, and has different memory capacities. The enlargement processing unit 23 determines the optimum enlargement pattern in accordance with the pattern of the image data stored in the first page memory 21 to perform the enlargement process on the image data.

Here, first, the image data sent from the image forming apparatus is received by the receiving unit 12, and the control unit 11 determines whether the image data is image data or a character code, and then separates them. Processing is performed. Image data varies depending on the image creation device,
Here, assuming that the data is 160 dpi, the data received as an image is 160 dpi.
1st page memory with a memory capacity of 1 page 2
Stored in 1.

On the other hand, although the character code varies depending on the resolution of the image output unit 4, assuming that it is possible to output at 320 dpi here, the data received by the character code is used by the character generation unit 13 for 320 dpi. And is stored in the second page memory 22 having a memory capacity of one page at 320 dpi. The image data once stored in the first page memory 21 is subjected to the following processing.

16 stored in the first page memory 21
When a part of the 0 dpi image data has a pattern as shown in FIGS. 2A and 2B, 320 d
If it is simply enlarged by the CPU in the control unit 11 to output in pi, it takes a long processing time, and as shown in FIGS. 3 (a) and 3 (b), respectively, the print quality becomes conspicuous and the print quality deteriorates.

In order to prevent this, the enlargement processing section 23 carries out the following processing. If the dots around the pixel of interest in the center have a pattern as shown in FIG. 2A, an enlarged pattern as shown in FIG. 4 is given accordingly. Examples of the results obtained by performing this process on all the dots in FIGS. 2 (a) and 2 (b) are shown in FIGS. 5 (a) and 5 (b), respectively, and are enlarged to a smooth and inconspicuous image image. can do.

This is 3 dot × 3 for simplicity in this case.
Since the line pattern is referred to, for example, as shown in FIG. 6, two FIFO (First in First out) memories 2 are provided.
4 and 25 and a ROM 26 having Latch (Look up table) data, the circuit can be realized. However, if the storage capacity of the FIFO memories 24 and 25 and the ROM 26 is increased, more dot patterns around the pixel of interest can be referred to. Therefore, more effective processing result can be obtained.

The data after the above processing is accumulated in the second page memory 22 where the character bit map data has already been accumulated. In this way the second
The data of the image in which the image and the character are stored in the page memory 22 is sent to the image output unit 4 as one page of data at 320 dpi.

FIG. 7 shows a conceptual diagram when the image output unit 4 is a laser beam printer. In FIG.
The LD (laser diode) drive unit 27 switches, for each dot, whether or not the laser light is emitted from the laser diode 28 in accordance with the image data sent. The laser light emitted from the laser diode 28 is charged by the charging unit 2.
A latent image is formed by irradiating the surface of the photoconductor 30 charged by 9 and toner is attached to the latent image by the developing unit (developing roller) 31 and then the sheet S is transferred by the transfer unit 32.
A visible image can be output by transferring the image onto the image and fixing it by the fixing unit 33.

FIG. 8 is a block diagram of an image forming apparatus showing another embodiment of the present invention, and the portions corresponding to those in FIG. 1 are designated by the same reference numerals. This embodiment has almost the same configuration as the above-described embodiment, but the image data enlarged by the enlargement processing unit 23 and the second page memory 2 are used.
A data synthesizing unit 41 for synthesizing the bit map data of the character stored in 2 is added.

In this embodiment, the image data is stored in the first page memory 21 and the character bitmap data is stored in the second page memory 22, respectively, which are the same as those in the above-described embodiment. After that, the image data stored in the first page memory 21 is sequentially enlarged by the enlargement processing unit 23 and sent to the data synthesizing unit 41, where the bitmap of characters stored in the second page memory 22 is displayed. The synthesis with the data is performed in real time.

FIG. 9 shows an example of the internal configuration of the data synthesizing section 41 when expanding from 160 dpi to 320 dpi. When one dot is enlarged by the enlargement processing unit 23 to 4 dots of 2 dots × 2 lines, 2 of the upper line
The data of the dots and the two dots of the lower line are sequentially stored in the first and second line memories 42 and 43, respectively, and when the data of two lines are stored one line at a time, the data of the next line becomes the first data. 3, fourth line memory 44, 4
Stored in 5.

The third and fourth line memories 44 and 45
While being stored in the first and second line memories 4
The data of 2, 43 are combined by the OR gate 46 while being synchronized with the data of the second page memory 22. Then, when all the data in the first and second line memories 42 and 43 are read out, the data of the next line is stored therein, while the data in the third and fourth line memories 44 and 45 is being read. Is read.

By repeating this operation, the synthesizing process can be performed in real time. In order to perform the above operation, the control unit 11 controls the line memories 42 to
The timing of reading and writing to 45 is controlled. The image data thus synthesized is sent to the image output unit 4, where it is printed out as a visible image at 320 dpi as in the above-described embodiment.

FIG. 10 is a block configuration diagram of an image forming apparatus showing still another embodiment of the present invention, and the portions corresponding to those in FIG. 1 are designated by the same reference numerals. In this embodiment, the control unit 11, the receiving unit 12, the character generating unit 13, the enlargement processing unit 23,
The image output unit 4 is the same as that in the above-mentioned embodiment.

The page memory 14 has a memory capacity of one page at 320 dpi. If the received data is image data, it is sent to the enlargement processing unit 23, and the image data enlarged in the same manner as in the above-described embodiment is written in the page memory 14. While this operation is being performed, even if the next character code is reserved, the control unit 11 is in a wait state, and the character generation unit 13 does not expand the character code into bitmap data.

When the enlarging process and writing of the image data are completed, the character code is expanded in the character generator 13 into a bit map and written in the page memory 14. When the writing of the image data and the character bitmap data to the page memory 14 is completed in this way, the image output unit 4 outputs the visible image of 320 dpi.

In this embodiment, the image data is 1
The case where the image output unit 4 is capable of printing 320 dpi at 60 dpi has been taken as an example, but the present invention can also be applied to the case where each of the image data and the image output unit 4 has any resolution.

[0031]

As described above, according to the image forming apparatus of claim 1, after the image data from the image forming apparatus is temporarily stored in the memory, the dot pattern around the target pixel is referred to, Since resolution conversion (image data expansion processing) is performed by determining an expansion pattern for the pixel of interest in accordance therewith, the converted image data and character bitmap data are superimposed and combined on the memory. High-speed output with high print quality can be obtained.

According to the image forming apparatus of claim 2,
After the image data from the image creating device is once stored in the memory, the resolution is converted by referring to the dot pattern around the pixel of interest and determining the enlargement pattern for the pixel of interest accordingly Since the image data and the bit map data of the character are combined in real time, it is possible to obtain an output of higher speed and higher printing quality.

Further, according to the image forming apparatus of the third aspect, by referring to the dot pattern around the pixel of interest of the image data from the image forming apparatus, and determining the enlargement pattern for the pixel of interest in accordance with the dot pattern, the resolution of Since the conversion is performed and the converted image data and the character bitmap data are sequentially written in the memory, an output with high print quality can be obtained with a small memory capacity.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a part of image data of 160 dpi.

FIG. 3 is an explanatory diagram showing an example of enlargement of the image data of FIG. 2 by a normal enlargement process.

FIG. 4 is an explanatory diagram showing an example of an enlargement pattern possessed by an enlargement processing unit 23 in FIG.

5 is an explanatory diagram showing an example of enlargement of the image data of FIG. 2 by the enlargement processing of the enlargement processing unit 23 of FIG.

FIG. 6 is a block configuration diagram showing an example of an enlargement processing unit 23 in FIG.

FIG. 7 is a conceptual diagram when the image output unit 4 of FIG. 1 is a laser printer.

FIG. 8 is a block configuration diagram of an image forming apparatus showing another embodiment of the present invention.

9 is a diagram showing an internal configuration example of a data synthesizing unit 41 of FIG.

FIG. 10 is a block configuration diagram of an image forming apparatus showing still another embodiment of the present invention.

FIG. 11 is a block diagram of an image forming system.

12 is a block diagram showing a conventional example of the image forming apparatus 2 of FIG.

[Explanation of symbols]

4 Image Output Section 11 Control Section 12 Reception Section 13 Character Generation Section 14 Page Memory 21 First Page Memory 22 Second Page Memory 23 Enlargement Processing Section 24, 25 FIFO Memory 26 ROM 41 Data Composing Section 42 First Line Memory 43 second line memory 44 third line memory 45 fourth line memory 46 OR gate

Claims (3)

[Claims] 1. An image forming apparatus that processes and outputs image data created by an image creating apparatus, and determines whether the image data sent from the image creating apparatus is image data or a character code. A data discriminating means, a first image accumulating means for accumulating image data, a character generating means for expanding a character code into a bit map, and a first for accumulating bit map data of the character expanded by the means. 2 image storage means,
Enlarging processing means for enlarging the image data by referring to a dot pattern around a pixel of interest of the image data accumulated in the first image accumulating means and determining an enlargement pattern for the pixel of interest in accordance therewith; Means for superimposing the image data enlarged by the means on the bitmap data of the characters accumulated in the second image accumulating means and accumulating, and image output means for outputting the image data accumulated by the means. An image forming apparatus characterized by being provided. 2. An image forming apparatus that processes and outputs image data created by an image creating apparatus, and determines whether the image data sent from the image creating apparatus is image data or a character code. A data discriminating means, a first image accumulating means for accumulating image data, a character generating means for expanding a character code into a bit map, and a first for accumulating bit map data of the character expanded by the means. 2 image storage means,
Enlarging processing means for enlarging the image data by referring to a dot pattern around a pixel of interest of the image data accumulated in the first image accumulating means and determining an enlargement pattern for the pixel of interest in accordance therewith; Means for synthesizing the image data enlarged by the means and the bitmap data of the character stored in the second image storage means in real time; and image output means for outputting the image data synthesized by the means. An image forming apparatus characterized by being provided. 3. An image forming apparatus that processes and outputs image data created by the image creating apparatus, and determines whether the image data sent from the image creating apparatus is image data or a character code. The data discriminating means, the enlarging processing means for enlarging the image data by referring to the dot pattern around the pixel of interest of the image data and determining the enlarging pattern for the pixel of interest according to the dot pattern, and expanding the character code into a bitmap. Character generating means, image storing means for storing image data, and image data sent from the image creating device when the image data is judged to be image data by the data judging means. When the character code is enlarged by the enlargement processing means and the character code is determined to be the character code, By expanded by the character generating means, and sequentially writes the control unit to each of the image storage unit, the image forming apparatus characterized by comprising an image output means for outputting the image data stored in said image storage means.