JP2523213B2 - Page printer print control method - Google Patents

Description

DETAILED DESCRIPTION [Overview] A page printer print control method for mapping pixel data of a character generator or the like onto a bitmap memory and printing the same. A high-speed print control is enabled by selecting an optimum data expansion means. For mapping the pixel data to the bitmap memory, the first means for mapping by the software through the microprocessor and the second means for mapping by the hardware by activating a dedicated logic circuit. Means and means for dynamically switching the first means and the second means are provided, and the first means and the second means are switched depending on the condition to perform mapping.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a page printer print control system that maps pixel data of a character generator or the like onto a bitmap memory and prints it.

[Conventional technology]

FIG. 5 is an overall block diagram of a conventional page printer control unit, FIG. 6 is an implementation example of the conventional technique, and FIG. 7 is an IC shown in FIG.
An example of a logic circuit is shown.

When receiving a print request from the host computer, the page printer 20 shown in FIG. 5 receives data by the data input unit 22 and analyzes the data by the data processing unit 23. The data processing unit 23 passes the analysis result to the print position control unit 24 and the print data control unit 25, and the print data control unit 25 stores the print data represented in the intermediate format in the print data storage unit 10.

The print start control unit 21 receives the notification from the data processing unit 23, and the bitmap data write control unit 11 and the video output unit
26 start control.

The bitmap data writing control unit 11 expands the print data read from the print data storage unit 10 into bitmap data based on the font data stored in the character generator 16, and stores it in the bitmap memory 17.

The video output unit 26 reads the bitmap data stored in the bitmap memory 17, converts it into a video signal, and passes it to the print control unit 27. The print control unit 27 prints based on the video signal.

As a method for expanding the pixel data of the character generator 16 or the like into the bitmap memory 17, the sixth conventional method is used.
As shown in FIG. 6 (a), a method of performing software control via the microprocessor 30, and FIG. 6 (b).
As shown in, the microprocessor 30 performs only the initial setting, and the actual expansion is performed by the IC logic circuit 34 configured by the LSI.

In FIG. 6, 30 is a microprocessor (MPU) that executes a microprogram, 31 is a random access memory (RAM), 32 is a read-only memory (ROM) that stores the control program 33, and 34 is pixel data. expand
Represents an IC logic circuit.

The IC logic circuit 34 is configured, for example, as shown in FIG. 7, and transfers the source data of the character generator 16 and the data read from the memory of the transfer destination to the transfer data processing circuit 40 that takes the logical sum. A transfer data size register control circuit 41 for setting the number of words and lines of data, a source address control circuit 42 for updating the source address of the character generator 16, and a one-line transfer control circuit for controlling the transfer destination address. It has 43 and. The IC logic circuit as shown in Fig. 7
Since 34 is well known, the explanation here is limited to this extent.

[Problems to be Solved by the Invention] For pixel control of a page printer, as shown in FIG. 6A, a microprocessor 30 is used to expand CG data in a bitmap memory 17, and As shown in the figure (b), there is a method of developing by hardware control without directly going through the microprocessor 30.

In the prior art, only one of these is used, and there is no page printer having both functions.

The expansion of pixel data into the bitmap memory 17
In general, the hardware control method is faster, but when the amount of data to be expanded is small, it takes more time to initialize the circuit than the data transfer time, so software control is needed rather than hardware logic control. Can be processed faster.

That is, if all pixel data expansion is controlled by hardware logic, if a large amount of pixel data expansion with a small amount of data enters, it will be much slower than software expansion.

An object of the present invention is to solve the above-mentioned problems, and to select an optimum data expansion means to enable high-speed printing control.

[Means for solving the problem]

 FIG. 1 is an explanatory view of the principle of the present invention.

In FIG. 1, 10 is a print data storage unit that stores coded print data, 11 is a bitmap data write control unit that creates bitmap data based on the print data, 12 is a write control switching determination unit, and 13 is A write control switching unit, 14 is a bitmap data writing unit that performs data expansion by software control, 15 is a bitmap data writing unit that performs data expansion by hardware control, and 16 is a character generator that stores pixel data that constitutes a character font (CG), 17 represents a bitmap memory for storing the data to be printed in the bitmap format.

The bitmap data writing unit 14 is means for expanding data in the bitmap memory 17 by software control as shown in FIG. On the other hand, the bit map data writing unit 15 is as shown in FIG.
It is a means for expanding data in the bitmap memory 17 by hardware control.

In the present invention, 2 of the bitmap data write units 14 and 15 are used.
One means is incorporated, the write control switching determination section 12 determines which means is to be used, and the write control switching section 13 selects one that can be developed at high speed.

[Action]

According to the present invention, the hardware control method and the software control method are switched depending on the condition of the amount of data, etc., so that the data can be expanded at higher speed regardless of the amount of data.

[Embodiment] FIG. 2 is a comparison diagram of transfer time of character data by a hardware control system and a software control system, and FIG. 3 is a process explanatory diagram of a write control switching determination unit according to an embodiment of the present invention, FIG. Shows a processing flow of a bitmap data writing unit according to an embodiment of the present invention.

For example, the software control method shown in FIG.
Comparing the transfer time per character by the hardware control method shown in FIG. 6B, the size of the transfer time differs depending on the size of the character data, as shown in FIG.

If the size of the character data (height x width) is small,
The software control method has a shorter transfer time and higher speed than the hardware control method. On the other hand, if the size of the character data exceeds about 20 × 20 dots, the hardware control method is faster.

Therefore, the write control switching determination unit 12 shown in FIG.
Selects the data expansion means by the processing shown in FIG. 3, for example. That is, when the height of the character data is 20 rasters or less and when the width of the character data is 20 dots or less, the bitmap data writing unit 14 is activated by software control, and when it is more than that, hardware control is performed. And activates the bitmap data writing unit 15.

In addition, the judgment condition by this data amount is an example,
Other judgment conditions can be set according to the design conditions.

The bitmap data writing unit 14 expands the data to the bitmap memory 17 by the processing shown in FIG.

From the character generator 16, height, width and X
Read character information such as coordinate and Y coordinate bitmap address.

A write destination address in the bitmap memory 17 is calculated.

 Initialize the work data write counter.

The pixel data of the character is transferred to the writing destination of the bitmap memory 17.

The process is repeated until the writing of all pixel data is completed, and when completed, the expansion process for one character is completed.

Since the bitmap data writing unit 15 is developed by the hardware logic, the processing shown in FIG.
I do.

From the character generator 16, height, width and X
Read character information such as coordinate and Y coordinate bitmap address.

A write destination address in the bitmap memory 17 is calculated. The process is the same as that under software control.

Next, each character information is set in the hardware port of the IC logic circuit 34 as shown in FIG.

Also, write destination information to the bitmap memory 17
Similarly, it is set to the hardware port of the IC logic circuit 34 as shown in FIG.

When the above preparation is completed, a write command is issued to the IC logic circuit 34.

As a result, the expansion into the bitmap memory 17 by hardware is performed.

〔The invention's effect〕

As described above, according to the present invention, it is possible to perform optimum data expansion according to the amount of pixel data, etc., so that it is possible to speed up print control.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention, FIG. 2 is a comparison diagram of transfer time of character data by a hardware control system and a software control system, and FIG. 3 is a write control switching judging unit according to one embodiment of the present invention. FIG. 4 is an explanatory diagram of processing, FIG. 4 is a processing flow of a bitmap data writing unit according to an embodiment of the present invention, FIG. 5 is an overall block diagram of a conventional page printer control unit, FIG. FIG. 7 shows an example of the IC logic circuit shown in FIG. In the figure, 10 is a print data storage unit, 11 is a bitmap data write control unit, 12 is a write control switching determination unit, 13 is a write control switching unit, 14 is a bitmap data writing unit, 15 is a bitmap data writing unit, 16 is a character generator and 17 is a bit map memory.

Claims (1)

(57) [Claims] 1. A page printer print control system for mapping pixel data of a character generator (16) or the like onto a bitmap memory (17) for printing, and when a pixel data is mapped onto the bitmap memory, a microprocessor is used. First means (14) for mapping by software, and second means (15) for mapping by hardware by activating a dedicated logic circuit, which has the same processing function as the first means, and A page printer print control system characterized by further comprising means (12, 13) for dynamically switching the first means and the second means for each data to be mapped according to the condition of the data to be mapped in the bitmap memory. .