KR20060121529A - Apparatus and method for rotating image in printer - Google Patents

Abstract

A device and a method for rotating image data in a printer are provided to reduce a rotation processing time and a storage device by converting the image data with hardware according to a direction of a printing sheet when printing data generated in the printer is different from the direction of the printing sheet. An image data processor(120) generates the printing data having multiple lines. A rotating part(150) reads the image data generated from the image data processor in a burst unit by each line and rotates the read image data. An image output part(160) outputs the image data generated in the rotating part. The rotating part includes a DMA(Direct Memory Access) controller(152) reading the generated image data of each line in the burst unit of a DMA mode, a rotator(154) performing bitmap rotation of the read image data to a specific angle, a buffer(156) storing the rotated image data in the line unit, and a parallel/serial converter(158) converting the image data stored in the buffer into serial data.

Description

Image data rotating apparatus and its method in an image output apparatus {Apparatus and method for rotating image in printer}

1 is a block diagram of an image output apparatus according to the present invention.

2 illustrates bitmap data before rotation and bitmap data after rotation according to the present invention.

FIG. 3 shows a temporary example of reading by a 40-bit burst per line of the DMA controller of FIG. 1.

FIG. 4 is a diagram illustrating one embodiment of rotating image data in the rotating apparatus of FIG. 1.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an image output apparatus, and more particularly, to an image data rotating apparatus and a method for rotating image data in accordance with a paper direction.

Usually, the direction of printing on the sheet of the image output apparatus and the direction of the image data are the same as the vertical direction. However, when paper is fed in the horizontal direction depending on the image output device, the generated vertical image data and the direction are different from each other. To do this, it is necessary to rotate the direction of image data that has already been generated.

In the conventional image rotation processing apparatus, when the print data generated by the printing apparatus is different from the paper direction of the image output apparatus, a portion for reading already created data from the storage device, a portion for reading and rotating in bits, and a newly generated portion It consists of writing data back into memory.

Therefore, when the print data generated by the printing device is different from the paper direction of the image output device, the software reads all the data and regenerates the print data rotated to match the paper direction of the output device. All data must be read in sequence and written back to storage.

However, conventionally, in order to match the print data generated by the printing apparatus with the paper direction of the image output apparatus, it has to be read and rotated in order from the storage apparatus, and the rotated data has to be calculated as an address in bits and used as the storage apparatus again. Since the image rotation processing method requires a read / write operation to a storage device and an algorithm for rotating in bits in software, it consumes a lot of time and additionally requires a storage device. Accordingly, the conventional image rotation processing method requires a lot of speed and storage device according to the paper direction, and the price of the entire system also increases to compensate for this.

The technical problem to be achieved by the present invention is to reduce the rotation processing time and the storage device by rotating and converting the image data to match the paper direction in hardware when the print data generated in the printing device and the paper direction of the image output device are different from each other. An image data rotating apparatus and a method thereof are provided.

In order to solve the above technical problem, the present invention provides an image printing apparatus,

Image data processing means for generating image output data having a plurality of lines;

Rotation means for reading the image data generated by the image data processing means in burst units every line and rotating the predetermined angle;

An image output section for outputting image data generated by the rotation means, wherein the rotation means

A memory access control unit which reads the generated image data in burst units of a direct memory access method every line;

A rotator unit rotating the image data read by the memory access control unit at a predetermined angle;

A buffer unit which stores image data rotated by the rotator unit in line units;

And a parallel / serial converter for converting the image data stored in the buffer into serial data.

In order to solve the above other technical problem, the present invention provides a process for generating and storing image data having a plurality of lines;

Reading the stored image data in burst units every line;

Sequentially writing the image data read in the process to a designated address and rotating the image data at a predetermined angle;

And storing the image data bit by bit for the plurality of lines in a vertical direction in one page.

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

1 is an overall block diagram of an image output apparatus according to the present invention.

Referring to FIG. 1, an image output apparatus includes an image data generation unit 120, a rotation module unit 150, and an image output unit 160.

The image data processing unit 120 includes a central processing unit (CPU) 128 that controls input and output of image data, a random access memory (RAM) 122 that temporarily stores image data, and a ROM that stores a program; Read Only Memory) 124, a host interface 126 for interfacing with a host computer, and an operation panel 129 for allowing a user to manipulate data input and output.

That is, the image data processing unit 120 generates and stores image output data input from the outside, and then rotates the image output data stored in synchronization with the page sync signal output from the laser scanning unit (LSU) of the image output unit 160. Output to the module unit 150. At this time, the image data generated by the image data processing unit 120 is stored in the RAM 122 in an unrotated image state (①).

The rotation module unit 150 includes a DMA controller 152, a rotator 154, a line buffer 156, and a parallel / serial converter 158, and image data generated by the image data processing unit 120. Lead in bursts to rotate 90 degrees or 270 degrees.

That is, the DMA controller 152 reads the stored image data in the RAM 122 in burst units by a direct memory access (DMA) method to convert the stored image data into the paper feed direction of the image output unit 160. (②). The DMA controller 152 transmits the read image data to the rotator 154 (3). The rotator 154 rotates the received data by 90 degrees and sends the rotated image data to the line buffer 156 (4). The rotator algorithm can be implemented in several ways, such as addressing or hardware design. For example, when data to be read is stored in a memory in a horizontal (vertical) direction and data stored in the memory is read in a vertical (horizontal) direction, the original data direction is rotated by 90 degrees. The line buffer 156 stores image data rotated 90 degrees in the rotator 154 in bitmap units for all lines 1, 2, 3, ... N in the vertical direction in one page. Are stored and output image data rotated in accordance with the paper feed direction to the parallel / serial converter 158 (⑤). The parallel / serial converter 158 configures the bitmap data read from the line buffer 156 in serial and transmits the bitmap data to the image output unit 160 in synchronization with the video clock generated by the image output unit 160. .

The image output unit 160 includes a laser diode, a rotating mirror, and an imaging lens to receive image data from the rotation module unit 150 and output an image through laser scanning. In other words, the laser beam output from the laser diode is deflected by the rotating polyhedron and then scanned through a imaging lens to a photosensitive drum (not shown).

2 illustrates bitmap data before rotation and bitmap data after rotation according to the present invention.

Referring to FIG. 2, the image data of a bitmap having an size of n x m is rotated into a bitmap of an m x n form so as to match the paper feeding direction of the image output apparatus, thereby generating the bitmap image data.

FIG. 3 shows an example of reading with a 4-bit burst per line of the DMA controller of FIG. 1.

Referring to FIG. 3, when reading in a word size (32 bits), the DMA address must increase in units of lines. That is, since the size of the line is m bits, the start address of the next line becomes (current address + m / 8). If the DMA operation does not read in bursts, it reads one word per line, which requires the basic cycle required for the read operation. In this case, the system's bus load increases and it is not useful. Thus, the present invention accesses every line in burst units (e.g., 4-bit burst) for every DMA operation.

4 is a conceptual diagram illustrating a rotation operation of image data in the rotator 154 of FIG. 1.

Referring to FIG. 4, the DMA controller 152 reads in 4-bit bursts every line for 1..n lines in the vertical direction on the entire page. The rotator 154 then sequentially writes the read 4-bit burst data to the specified address of the line buffer in the horizontal direction, over all the lines (1, 2, 3, ... n) in one page. Save as a bitmap

The best embodiments have been disclosed in the drawings and the specification, and the terminology used herein is for the purpose of describing the invention only and is not intended to be limiting of the scope of the invention as defined in the appended claims or claims. Therefore, those skilled in the art will be capable of various modifications and other equivalent embodiments from this, and therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

As described above, according to the present invention, when the print data generated by the device is different from each other in the paper direction of the image output device, the image data is rotated and converted to match the paper direction by hardware to maintain constant performance regardless of the feeding direction. Can be. It also reduces speed and hardware load by maintaining a burst read during DMA operation.

Claims (5)

In the image printing apparatus, Image data processing means for generating image output data having a plurality of lines; Rotation means for reading the image data generated by the image data processing means in burst units every line and rotating the predetermined angle; And an image output unit for outputting image data generated by the rotation means. The method of claim 1 wherein the rotation means A memory access control unit which reads the generated image data in burst units of a direct memory access method every line; A rotator unit which bitmap rotates the image data read by the memory access control unit at a predetermined angle; A buffer unit which stores image data rotated by the rotator unit in line units; And a parallel / serial conversion unit for converting the image data stored in the buffer unit into serial data. The image data rotating apparatus according to claim 2, wherein the memory access control unit increases the address in units of lines. Generating and storing a plurality of line unit image data; Reading the stored image data in burst units every line; Rotating the bitmap at a predetermined angle on the image data read in the process; And storing the image data of one page in units of bits for the plurality of lines in a direction of a predetermined angle, and outputting the stored image data. The image data rotating method according to claim 4, wherein in the burst read process of the image data, if the line size is m bits, the start address of the next line is the current address + m / 8.

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