KR19990049403A - Image forming apparatus - Google Patents

Abstract

An image forming apparatus according to the present invention includes a video controller for processing a print command and print data input from a host computer and outputting the final print data, and an engine unit for receiving print data from the video controller to perform printing. An image forming apparatus is characterized in that a video signal modulator for modulating print data into printable serial data is included in the video controller. According to this, the number of interface signal lines is reduced, thereby improving economics and reliability. In addition, even in the color correction, color correction can be performed only in the video controller, so that color correction can be easily and more quickly performed, and thus, a color correction program is also simplified.

Description

Image forming apparatus

The present invention relates to an image forming apparatus.

An image forming apparatus is a device that reproduces a character or an image on a recording medium, such as paper, in accordance with a transmitted print command and print data, and generally receives a print command and print data through a communication port or the like connected to a computer.

1 is a block diagram showing a schematic configuration of a conventional image forming apparatus. Referring to FIG. 1, a conventional image forming apparatus includes a video controller 1 for processing print data input from a host computer (not shown) and an engine unit 2 for printing.

The video controller 1 includes a central processing unit 11, various memories 12, 13, 14, and a communication port 15. The memory includes a program memory 12, a font memory 13, an image buffer memory 14, and the like.

The central processing unit 11 controls the overall operation of the video controller 1 according to the print command input through the communication port 15 and the synchronization signal transmitted from the engine unit 2. Various data processing programs are stored in the program memory 12, data relating to various fonts are stored in the font memory 13, and input print data is temporarily stored in the image buffer memory 14. The print data stored in this image buffer memory 14 is transmitted to the engine unit 2 via the interface 3 in accordance with the control signal of the central processing unit 11.

The engine unit 2 includes a video signal modulating unit 21 and an exposure scanning unit 22. In addition, various engine units such as a transfer unit (not shown) and a developing unit (not shown) are included.

The video signal modulator 21 modulates the print data input from the video controller 1 and outputs the serial data in the form of serial data. The modulated output data is input to the exposure scanning unit 22 to perform printing.

However, such a conventional image forming apparatus has the following problems.

First, in order to transmit the print data at high speed from the video controller 1 to the video signal modulator 21 of the engine unit 2, the print data must be transmitted in parallel, so that various signal lines of the interface 3 Increases.

Second, since the video signal modulator 21 is located in the engine unit 2, color correction is performed by transmitting color correction data from the video controller 1 to the engine unit 2, so that the time required for printing This lengthens.

Third, a transmission program for transmitting the color correction data from the video controller 1 to the engine unit 2, and a setting program for setting the color correction by the received color correction data are complicated.

The present invention has been made to solve the above problems, and an object thereof is to provide an image forming apparatus in which data transmission between the video controller 1 and the engine unit 2 is simple.

1 is a block diagram showing a schematic configuration of a conventional image forming apparatus.

2 is a block diagram showing a schematic configuration of an image forming apparatus according to the present invention;

3 is a block diagram showing a schematic configuration of a video signal modulator of the image forming apparatus according to the present invention of FIG.

<Explanation of symbols for main parts of the drawings>

10 Video controller 20 Engine section

30.Interface 101 ... Central Processing Unit

102 Program memory 103 Font memory

104 ... image buffer memory 105 ... Video signal modulator

106 Communication port 201 Exposure scan

51 ... Data Processing Controller 52 ... Buffer Memory

53 ... Parallel / Serial Converters 54 ... First Switch

55 ... Modulator 56 ... Oscillator

57 ... LUT memory 58 ... 2nd switch

59 ... NOT gate 60 ... mixer

In order to achieve the above object, the image forming apparatus according to the present invention, a video controller for processing the print command and the print data input from the host computer to output the final print data, and prints the print data received from the video controller An image forming apparatus connected by an engine unit for performing an interface, wherein the video controller includes a video signal modulator for modulating the print data into printable serial data.

Hereinafter, an image forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a schematic configuration of an image forming apparatus according to the present invention. As illustrated, the image forming apparatus according to the present invention includes a video controller (Module) for modulating the print data output from the image buffer memory 104 into serial data in the form of a bitmap. It is characterized by the points included in 10). Therefore, since the final data form output from the video controller 10 is serial data, the configuration of the interface 30 with the engine unit 20 is simplified.

This will be described in more detail.

Referring to FIG. 2, the image forming apparatus according to the present invention includes a video controller 10 for processing input print data and an engine unit 20 for printing.

The video controller 10 includes a central processing unit 101, various memories 102, 103, 104, a video signal modulator 105, and a communication port 106. The memory includes a program memory 102, a font memory 103, an image buffer memory 104, and the like.

The central processing unit 101 controls the overall operation of the video controller 10 in accordance with a print command input from a host computer (not shown) through the communication port 106. The program memory 102 stores various data processing programs, the font memory 103 stores data relating to various fonts, and the image buffer memory 104 temporarily stores input print data. The print data stored in this image buffer memory 104 is input to the video signal modulator 105 in accordance with a predetermined control signal.

The video signal modulator 105 converts the print data input from the image buffer memory 104 into serial data in the form of a bitmap, and transmits it to the exposure scan unit 201 of the engine unit 20 so that printing is performed. do.

3 illustrates an example of an internal system configuration of the video signal modulator 105. Referring to FIG. 3, the operation of the video signal modulator 105 will be described in more detail.

First, as shown in FIG. 3, the video signal modulator 105 includes a data processing controller 51, a parallel / serial converter 53, a first switch 54, a modulator 55, and a second switch ( 58 and a mixer 60.

The data processing controller 51 generates a first switching control signal when the print data input from the image buffer memory 104 is at a binary level, and when the print data is at a multi level. Generates a second switching control signal. The parallel / serial converter 53 converts the parallel data input through the data processing controller 51 into serial data and outputs the serial data. The first switch 54 is turned on when the first switching control signal from the data processing controller 51 is generated, and inputs the input print data to the parallel / serial converter 53. The modulator 55 modulates, for example, pulse-width modulates, the input print data and outputs the modulated data. The second switch 58 is turned on when the second switching control signal from the data processing controller 51 is generated, and inputs the input print data to the modulator 55. The mixer 60 is a kind of OR gate, and selectively transmits data output from the parallel / serial converter 53 and the modulator 55 to the exposure scan unit 201 of the engine unit.

Meanwhile, a FIFO (First-In, First-Out) buffer memory 52 for buffering data transmission is further provided, and generates a modulation clock having a modulation frequency of the modulator 55 to the modulator 55. A LUT memory 57 is further provided which stores an oscillator 56 for supplying and a look up table for adjusting modulation characteristics.

In addition, the NOT gate 59 is further provided to prevent the first and second switches 54 and 58 from being turned on at the same time. The input terminal of the NOT gate 59 is connected to the data processing controller 51 and the second switch 58, and the output terminal is connected to the first switch 54. Therefore, when a first switching control signal, for example, a low level signal is generated from the data processing controller 51, the second switch 58 is input as it is to maintain the off state. The first switch 54 is inverted and input to a high level signal by the NOT gate 59. On the other hand, when a second switching control signal, for example, a high level signal is generated from the data processing controller 51, the second switch 58 is input with a high level signal, and the first switch 54 is a NOT gate. By 59, the signal is inverted and turned off at a low level signal. Therefore, the state in which the first and second switches 54 and 58 are simultaneously turned on does not occur.

On the other hand, in the color image forming apparatus, a video signal modulator is provided for each color and input print data is processed for each color.

As described above, since the data output from the video controller 10 is serial data output from the parallel / serial converter 53 or the modulator 55, the interface 30 with the engine unit 20 can be more easily implemented.

As described above, according to the image forming apparatus according to the present invention, by including a video signal modulator that modulates print data in the video controller, the number of interface signal lines is reduced, thereby improving economic efficiency and reliability. In addition, even in the color correction, color correction can be performed only in the video controller, so that color correction can be easily and more quickly performed, and thus, a color correction program is also simplified.

Claims (5)

An image forming apparatus in which a video controller for processing a print command and print data input from a host computer and outputting the final print data and an engine unit for receiving print data from the video controller and performing printing are provided. And a video signal modulator for modulating the print data into printable serial data. The method of claim 1, wherein the video controller, A central processing unit that performs overall control when a print command and print data are input; An image buffer memory which expands and stores the print data input by the control signal of the central processing unit into print data of a predetermined unit; And And a video signal modulator for processing the print data from the image buffer memory according to the control signal of the central processing unit and transmitting the print data to the engine unit. The video signal modulator of claim 2, wherein the video signal modulator comprises: A data processing controller generating a first switching control signal when the print data input from the image buffer memory is a binary level, and generating a second switching control signal when the print data is multi-level; A parallel / serial converter converting parallel data input through the data processing controller into serial data and outputting the serial data; A first switch which is turned on when the first switching control signal is generated and inputs the print data to the parallel / serial converter; A modulator for outputting pulse width modulated input print data; A second switch which is turned on when the second switching control signal is generated and inputs the print data to the modulator; And And a mixer for transmitting data output from the parallel / serial converter or the modulator to the engine unit. The video signal modulator of claim 2, wherein the video signal modulator comprises: And a buffer memory for buffering the data transfer from the data processing controller in a FIFO manner. The video signal modulator of claim 2, wherein the video signal modulator comprises: An oscillator for generating a modulation clock having a modulation frequency of the modulator and supplying the modulated clock to the modulator; And And a LUT memory in which a lookup table for adjusting modulation characteristics of the modulator is stored.