JPS60141573A - Page printer - Google Patents

Abstract

PURPOSE:To obtain even an overlap printing function, by a method wherein a made of gaining access independently to two independent page memories and a mode of gaining access simultaneously to both of the page memories at the same address can be selectively used, in a laser printer. CONSTITUTION:In each of the page memories 11, 12, it is possible to select an address for a direct memory access (DMA) action and an address for a CPU action by a selector 13, 14. In data buses of the memories 11, 12, it is possible to select the read data by buffer gates 15, 16, respectively. When using one of the memories for an overlap printing function, selecting cires DMA#1, DMA#2 are simultaneously made to be high (H), buffer gates 17, 18 are turned OFF, only a selector 19 is turned ON, whereby the same DMA address ADD is given to the memories 11, 12, and two character codes are simultaneously obtained to perform overlap printing. Accordingly, high-speed printing can be conducted and an overlap printing function can be also obtained, with low-capacity page memories.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a page printer, and more particularly to a laser printer that arranges character code information two-dimensionally in a page memory and switches between high-speed printing and overlapping printing. be.

Since prior art laser printers cannot be stopped mid-print, they must output dot data at a constant frequency in synchronization with raster signals.

Therefore, a page memory is provided that arranges characters two-dimensionally, and the code signal sent from an external device is converted into a code corresponding to the address of the pattern memory.
It is stored in the page memory by the U operation, and when the reception of one page worth of data is completed, it leaves the control of the CI) U and transfers the data to the I) M A (1) directMemory A.
(ccess) operation to obtain turn data (raster data). Therefore, since the page memory cannot be accessed from the CPU during the printing operation, data reception for the next page must wait until the printing operation is completed. Therefore, the printing operation becomes intermittent and slow. Therefore, conventionally, in order to prevent this delay, two
A page base is prepared and printing and receiving operations are assigned alternately to avoid slowing down.

- When printing a new character by overlapping two characters, inserting a character into a figure such as a graph, or inserting a character into an image, overlapping printing is performed. This requires storing different character codes in the same character position in the page memory, which further doubles the tolerance of the page memory.

SUMMARY OF THE INVENTION In order to improve such conventional problems, it is an object of the present invention to provide a page printer capable of high-speed printing and overprinting without increasing the page memory St. be.

composition Hereinafter, the configuration of the present invention will be explained using examples.

As mentioned above, in order to maintain the high printing speed of a laser printer that prints by raster scanning ('i), page memory for two pages is required, and in order to add a character overprinting function. However, the overprint function is not a function that is required all the time, but only needs to be performed when requested. Therefore, in the present invention, normally two The page memory of the page is used alternately for printing and receiving operations to keep the printing speed high, and only when required is it used for the overlap printing function at the expense of printing speed (16 formats, reducing overall cost) We aim to

FIG. 1 is a block diagram of a print control section of a page printer according to an embodiment of the present invention, and FIG. 2 is a diagram showing character arrangement in the page memory of FIG. 1.

In FIG. 1, 1 is page memory and ? 1jlJ
control circuit, 2 is a character pattern memory, 3 is a data register, 5 is a parallel/serial conversion circuit, 5 is a character address counter, 6 is a row address counter, 7 is a dot counter, 8 is a line counter, 9 is a memory access timing circuit.

The page memory 1 shown in FIG. 1 is stored in a character arrangement as shown in FIG. 2, and is controlled by one character and one line year. In addition, the character (graphic) code sent from the external device is stored in the CI so that it becomes the storage start address of the pattern memory 2 that stores the corresponding character (graphic) pattern.
) [The code is converted by J and then stored in page memory 1.

The dot counter 7 in FIG. 1 is driven by the main running distortion clock and controls the width (or height) direction of the character matrix, and when the character width reaches a predetermined number of dots, the character address counter 5 count up. Character address counter 5 controls character addresses in page memory 1, and is reset to the initial state together with dot counter 7 at the end of one main scanning line.

The line counter 8 is driven by the sub-scanning clock, controls the height or width of the character matrix, and counts up the line address counter 6 when the height of the character reaches a predetermined number of lines. . Row address counter 6 controls the row address of page memory 1. Page memory 1 specified by character address and line address
gives the starting address of the character matrix. Then, by determining four elements using this start address and the addresses from the dot counter 7 and the line counter 8, pattern data for a memory storage unit of a character matrix is obtained from the character pattern memory 2. This pattern data is converted into raster data by the parallel-to-serial conversion circuit 4 and output.

The above operation is a description of a case where printing operation (IJMA operation) is started with print data already stored in page memory 1. Print data is stored in the page memory 1 in advance by a program operation of the CPU.

Therefore, two sets of address buses and data buses for page memory 1 are provided, one for D1 to IA operation and one for CI)U operation, and data is read out using a DMA address only during printing operation. In addition, page memory 1 and 2 pages are provided, and code information received from an external device is converted into an internal code, and page memory selection/1d is provided.
Specify either PMl or PM2 and store it. When one page's worth of data has been stored, the page memory to be printed is designated by selection signals DMA1 and -DIVIA2, and either one is used for printing in the DIVI A operation. In other words, the two pages of page memory 1 are normally separated, and when one is used for printing operation (1) MA operation), the other is used for receiving operation (CPU operation), and both are used. It is controlled at 1 lil by switching at a timely manner so that the printing operation is not interrupted in November.

On the other hand, when there is a request from the external device 6 to change the function of the printer to enable overlapping printing, the printer functions to treat two pages of page memory 1 as one page.

FIG. 3 is a detailed block diagram of the page memory and one circuit on the i1+11 side in FIG. 1.

Each page memory 11.12 contains an I) MA address (A D 1.) used in an I) MA operation.
and CPU CI used in U operation U address (AD
D) is selected by the selector 13.14, and the data bus of the page memory 11.12 is configured to select the read data of CI) U by the buffer game) 15.16. There is.

During DMA, data to be read from page memory 11.12 can be selected by buffer gates 17.18.

For CPU operation, select line DI! IA#1. Both DMi4 and 2 are inactive, and both memos IJII.

12 both addresses are CPU U address (A I) I
)), and the gates Nl, l'J2. N3. It becomes possible to read and write via N4. page·
When initially clearing memo 'Jll, 12, page memory selection signal PM#1. Activate both PM4no2 and write zero data (cp'UWIt)
. To write data to the page memories 11 and 12 or read data from the page memories IJII and 12, activate either one of the selection signals pH+1゜i) M # 2 and use the CPU write signal (CP U
W It, ) or CI) U read signal (CP
UI (, 1)) to '1'' and at the same time data (C
1) UDATA) directly, page memo IJII, 12
terminal 1] IN or page memo 1J
11. Data read from terminal DOUT of 12 (CP
IJ DATA) to the CPU via buffer gates 15 and 16.

]) During M A operation, and page memo IJII, 1
When using 2 alternately, select line DIWA#1゜D
MA #2 is alternately activated and a DMA address is given to obtain DMA data.

Next, when using one of the page memories as an overprinting function, select @DMA41. By activating both DMA #2 at the same time, buffer gate 1-17
．． 18 is in a non-operating state, and only the selector 19 is in an operating state. Then, the same DMA address (A, l) D) is given to both page memories 11 and 12, and two character codes are obtained at the same time. The obtained two-by-one character code is used in the memory access timing circuit 9 of FIG.
, we first create a pattern based on one code.
After reading the pattern data from the memory 2 and holding it in the data register 3, another pattern data is read based on the other code, and the logical sum of the two is input to the parallel-to-serial conversion circuit. do. Parallel-serial conversion circuit 4
The overlaid pattern data is then converted to raster data and sent to a laser printer. Thereby, overlapping printing can be performed. In FIG. 3, a selection signal (DATA 5E
L) is a clock that provides sufficient time until the output data of page memo IJ11.12 becomes stable and pattern data is obtained from pattern memory 2, and that holds the data in data register 3 at the end of the period. give.

In the example, a laser printer was explained, but if it is a raster scanning printer, an electrostatic printer, an electrostatic printer,
Of course, the present invention can also be applied to various printers such as thermal printers and inkjet printers.

Effects As explained above, according to the present invention, two independent page memories can be used by selecting whether they are accessed independently or accessed at the same address at the same time, so pages with a small capacity can be used.・High-speed printing is possible using memory, and at the same time, it is also possible to implement an overlapping printing function.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a print control unit of a page printer showing an embodiment of the present invention, FIG. 2 is a diagram showing the character arrangement in the page memory of FIG. 1, and FIG. 3 is a page of the page shown in FIG. 1. - Detailed block diagram of memory and control circuit. 1: Page memory and its control circuit, 2: Character pattern memory, 3: Data register, 4: Parallel-to-serial conversion circuit, 5: Two-character address counter, C: Row address
Counter, ■ = dot counter, 8 lines counter, 9: Memory access timing, 11.12:
Page memory, 13.14.19: Selector, 15.
16°17.18: Buffer gate. Patent applicant Rico Co., Ltd. - Raster data character direction

Claims (1)

[Claims] page memory that stores code information in pages;
It has a pattern memory that stores graphic information corresponding to the above code information, and by counting raster scanning synchronization signals, position information is stored in the above page memory and pattern memory.
A page printer that outputs graphic information given as a memory address as raster data includes two independent page memories, means for independently accessing the page memories at different addresses, and a page printer that outputs graphic information as raster data. A page memory characterized by having means for simultaneously accessing the memory at the same address and means for selectively specifying one of the above two means.