JP3326838B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for visualizing and printing print data given as character codes, graphic data and the like.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the overall processing speed from being reduced by being restricted by the printing speed of a printing mechanism, print data is sequentially visualized regardless of the printing speed of the printing mechanism.
There has been proposed a technique in which the visualized bitmap data is temporarily stored in an external storage device such as a hard disk, and is developed again at the printing stage and transmitted to a printing mechanism. At this time, in order to effectively use the capacity of the external storage device, the bitmap data is compressed and encoded before being held.

FIG. 6 is a block diagram showing a conventional printing apparatus. 6, reference numeral 1 denotes a CPU (central processing unit);
2 is a program memory, 3 is a data memory, 41 is a decompression image memory, 42 is an output image memory, 17 is a compression / expansion device, 6 is a disk controller, 7 is a hard disk, 9 is a printing mechanism, 10 is a host computer, 11
Is a host interface, and 12 is an internal bus.

The program memory 2 is a memory for storing a processing program of the CPU 1, and the data memory 3 is for temporarily storing print data from the host computer 10 and for using it as a work area of the CPU 1. Memory. The development image memory 41
This is a memory for developing bitmap data for one page from the print data stored in the data memory 3. Further, the output image memory 42 is
Is a memory for decompressing bitmap data obtained by decompressing the encoded data stored in the printer unit 17 by the compression / decompression device 17, and outputs the data to the printing mechanism unit 9 via this.

The print data sent from the host computer 10 via the host interface 11 is first held in the data memory 3. The print data held in the data memory 3 is converted into bitmap data by the CPU 1 and then expanded in the expansion image memory 41. That is, it is visualized. The bitmap data expanded in the expansion image memory 41 is encoded by the compression / expansion device 17 and then stored in the hard disk 7 in page units.

During this time, the coded data in page units stored in the hard disk 7 is read out, and
Output to When outputting data from the hard disk 7 to the printing mechanism unit 9, the encoded data stored in the hard disk 7 is decoded by the compression / decompression device 17,
The image is temporarily expanded in the output image memory 42. Then, while reading data from the output image memory 42, the data is sent to the printing mechanism unit 9 to perform printing. In addition, as a conventional document related to such a printing apparatus, for example,
JP-A-3-213374 is known.

[0007]

However, in the prior art described above, since the compression / expansion device 17 is provided between the internal bus 12 and the hard disk 7, a large amount of uncompressed data is not stored on the internal bus 12. Is moved, the occupation time of the internal bus 12 becomes longer, and the CP
There is a problem that the visualization processing time of U1 is limited and the processing speed of the entire printing apparatus is reduced. An object of the present invention is to solve such a problem.

[0008]

According to a first aspect of the present invention, there is provided a bitmap data storage unit for storing bitmap data obtained by expanding input print data; Compression means for encoding the stored bitmap data; encoded data storage means for storing the encoded data encoded by the compression means; an internal bus connecting the respective means; and the bitmap data. When transferring bitmap data from the storage means to the compression means, the bitmap data is transferred without passing through the internal bus, and when transferring the coded data from the compression means to the coded data storage means, the data is transferred via the internal bus. And control means for controlling the transfer.

[0009]

[Operation] The encoded data read from the external storage means is sent to the decompression means through the internal bus, where it is decoded and printed by the printing mechanism means. Therefore, since the data flowing through the internal bus is the coded data before being decoded, the amount of flowing data is reduced, and the visualizing means including the CPU and the like can sufficiently secure the print data visualization processing time. Thus, the processing speed of the entire printing apparatus is improved.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. The reference numerals correspond to those in FIG. 6, 4 is an image memory, 5 is an image compression device, and 8 is an image decompression device. In the present invention, the compression / expansion device 17 in the prior art is divided into an image compression device 5 and an image decompression device 8, and the image
And the printing mechanism 9. Also,
By omitting the output image memory 42 provided in the prior art, the image decompression device 8 and the printing mechanism 9
To send the data directly.

The CPU 1 reads out the print data in the data memory 3, sequentially converts the print data into bitmap data, and develops it into the image memory 4. After the visualization of one page of data is completed, the CPU 1 activates the image compression device 5 and encodes the data in the image memory 4. The encoded data is transmitted to the hard disk 7 via the disk controller 6.
And is held until there is an output instruction.

After the storage of the encoded data for one page in the hard disk 7, the CPU 1 notifies the host computer 10, which is the host processor, that the visualization of the designated print data has been completed, and the next print operation is performed. Request data transfer. In this way, print data visualization processing is sequentially performed. On the other hand, when a print instruction is given from the host computer 10, the CPU 1 activates the image decompression device 8 and instructs the disk controller 6 to transfer encoded data. Then, the image decompression device 8 sequentially decodes the transferred encoded data and outputs the decoded data to the printing mechanism unit 9.

FIG. 2 is a block diagram showing an example of the internal configuration of the image decompression device. Reference numerals correspond to those in FIG. 1, 81 is a bus interface, 82 is an input buffer, 83 is an image decompression unit, 84 is an output buffer, 85
Is an output interface. In FIG. 2, solid arrows indicate flows of encoded data and decoded data, and dotted arrows indicate flows of control signals.

The bus interface 81 is connected to the internal bus 1
2 for exchanging data with the image expansion unit 8
3 to control the flow of control signals and encoded data. The image decompression unit 83 performs high-speed decoding of encoded data into bitmap data. The input buffer 82 and the output buffer 84 are provided with FIFO (First
(In First Out) It is composed of a memory or the like and holds encoded data or bitmap data corresponding to at least one line.

In this way, the encoded data read from the hard disk 7 is sent to the image decompression device 8 through the internal bus 12, where it is decoded and printed by the printing mechanism 9. Therefore, since the data flowing through the internal bus 12 is the coded data before being decoded, the amount of flowing data is reduced, and the CPU 1 can sufficiently secure the visualization processing time and the like. Further, since the output image memory provided in the prior art is omitted, a hard disk
Thus, there is no need to perform two-stage data transfer from the output image memory 42 to the printing mechanism unit 9 from the output image memory 42, and the processing time can be shortened accordingly.

FIG. 3 is a block diagram showing a second embodiment of the present invention. The reference numerals correspond to those in FIG. In this embodiment, a data bus for transferring encoded data is provided between the disk controller 6 and the image decompression device 8,
The internal bus 12 is not used for transferring the encoded data. By doing so, the amount of data flowing through the internal bus 12 can be further reduced.

FIG. 4 is a block diagram showing a third embodiment of the present invention. Reference numerals correspond to those in FIG. 1, 13 is an image developing device interface, 14 is an image developing device, 15
Is a local bus. In this embodiment, the visualization of the print data held in the data memory 3 is performed by providing a dedicated image developing device 14 instead of the CPU 1 and improving the processing speed by providing a plurality of image memories. ing. That is, while encoding the bitmap data expanded in one image memory 4-1 (4-2),
The bitmap data of the next page is expanded in the other image memory 4-2 (4-1) to improve the speed of the visualization process and the encoding process.

It should be noted that a processor dedicated to image development can be used as the image development device 14,
U may be separately provided and formed. When a sub CPU is provided, it is necessary to provide a program memory and a data memory for the sub CPU on the local bus 15.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention. The reference numerals correspond to those in FIG. 1, and 16 is a memory controller. In this embodiment, the image memory 4
Between the image compression device 5 and the memory controller 16
When transmitting bitmap data from the image memory 4 to the image compression device 5, the memory controller 16
Intervene. When reading the bitmap data from the image memory 4, the memory controller 16 appropriately changes the data reading position and the reading direction to rotate the image by 90 °, 180 °, 270 °, or the like. It can be sent to the compression device 5 side.

In each of the above embodiments, the case where a hard disk is used as the external storage device has been described. However, the present invention is not limited to this. For example, a solid-state memory or a magneto-optical disk may be used. Also, the data memory for storing the print data is not limited to a RAM (random access memory), and a hard disk may be used.

[0021]

According to the first aspect of the present invention, when transferring bitmap data from the bitmap data storage means to the compression means, the bitmap data is transferred without passing through the internal bus, and is transferred from the compression means to the encoded data storage means. Since the coded data is transferred via the internal bus when the coded data is transferred, the coded data having a small data amount flows through the internal bus, thereby improving the processing speed of the image processing apparatus.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of an internal configuration of the image decompression device.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a conventional printing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CPU, 2 ... program memory, 3 ... data memory, 4 ... image memory, 5 ... image compression apparatus, 6 ... disk controller, 7 ... hard disk, 8 ... image decompression apparatus, 9 ... printing mechanism part, 10 ... host, 11 host interface, 12 internal bus, 13 image expansion device interface, 14 image expansion device, 15 local bus, 16 memory controller, 17 compression / expansion device, 41 image memory for expansion, 42 output Image memory 81 Bus interface 82 Input buffer 83 Image decompression unit 84 Output buffer 85
… Output interface

Claims (1)

(57) [Claims] 1. Bitmap data storage means for storing bitmap data obtained by expanding input print data; compression means for encoding bitmap data stored in the bitmap data storage means; Encoded data storage means for storing encoded encoded data; an internal bus connecting the means; and an internal bus for transferring bitmap data from the bitmap data storage means to the compression means. A control means for transferring the encoded data from the compression means to the encoded data storage means via the internal bus when transferring the encoded data from the compression means to the encoded data storage means. Processing equipment.