JPH0717075A - Printer device - Google Patents

Abstract

PURPOSE:To high-speedily execute enlargement and reduction processing of printing data without increasing the load of a CPU by equipping a parallel serial converter which converts image data sent from a DMA controlling part into serial data and also outputs the converted data synchronously with a synchronous signal outputted from an enlargement processing part and equipping a printing mechanism part. CONSTITUTION:The example is constituted of a bit map memory for containing image data, an enlargement-setting switch 60 for setting enlargement value (n) and an enlargement processing part 10 for outputting a synchronous signal correspondent to the enlargement value set by the switch 60. A printer device is constituted of a parallel serial converter 20 and a printing mechanism part 50 of image data sent from the converter 20. The converter 20 converts the image data sent from a DMA controlling part 30 for reading out the image data written in the memory 40 into serial data and also outputs the converted data synchronously with a synchronous signal outputted from the processing part 10. The need for special time is eliminated to perform the whole enlargement processing only by a hardware. The part dependent on a software is eliminated and therefore the sole possession of a CPU is made unnecessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer device,
In particular, it relates to a printer device having an enlargement / reduction function.

[0002]

2. Description of the Related Art In recent years, when printing contents created on a screen by a drawing / sentence creating device such as a word processor or a personal computer, it is often the case that only the printer device side sets the printing magnification and direction. Is coming.

FIG. 4 shows a conventional example disclosed in JP-A-02-277660.

In the conventional example of FIG. 4, a host computer 100 that outputs print data and a receive data buffer 2 that temporarily holds print data transmitted from the host computer 100.
02, a bitmap memory 203 for storing the print data after the bitmap expansion and enlargement processing of the print data, and the print data written in the reception data buffer 202 is read and the bitmap expansion and enlargement processing is performed. A CPU 201 that writes the processed data in the bitmap memory 203, a recording unit 205 that prints the received data, and a bitmap controller 204 that reads the processed data from the bitmap memory 203 and transfers the processed data to the recording unit 205 are provided. There is.

Next, the operation of the above conventional example will be described.

[0006] The host computer 100 outputs print information and print data.

[0007]. Upon receiving the print information, the CPU 201 stores the print data in the received data buffer 202.

[0008] Subsequently, the CPU 201 reads the print data from the received data buffer 202 and performs the enlargement / reduction processing according to the magnification specified by the print information.

[0009]. Then, when the enlargement / reduction processing is completed, the CPU 201 stores the enlarged / reduced print data for one page in the bitmap memory 203 in the bitmap format, and passes control to the bitmap controller 204.

[0010]. Bitmap controller 204
The enlarged / reduced print data is sequentially read from the bitmap memory 203 and transferred to the recording unit 205.

[0011]. The recording unit 205 prints the print data from the bitmap controller 204.

[0012]

However, in the above conventional example, only the CPU performs the enlargement / reduction processing,
Moreover, since the CPU cannot perform other processing during that time, waiting for printing frequently occurs, and it takes a long time for the printing processing.

[0013]

SUMMARY OF THE INVENTION The object of the present invention is to improve the inconveniences of the prior art, particularly without increasing the load on the CPU,
It is an object of the present invention to provide a printer device capable of performing enlargement / reduction processing of print data at high speed.

[0014]

Therefore, according to the present invention, a bit map memory for storing image data, an enlargement setting switch for setting an enlargement value, and a synchronization signal corresponding to the enlargement value set by the enlargement setting switch. , A DMA control unit for sequentially reading the image data written in the bit map memory, the image data from the DMA control unit is converted into serial data, and the converted data is converted into a synchronization signal from the enlargement processing unit. It is configured to include a parallel-to-serial converter that outputs in synchronization with each other, and a printing mechanism unit that prints image data from the parallel-to-serial converter. This aims to achieve the above-mentioned object.

[0015]

The bit map memory stores the image data sent from the host device.

The operator sets the enlargement value n with the enlargement setting switch.

The enlargement processing section outputs a synchronization signal having a frequency of 1 / n to the parallel-serial converter based on the enlargement value n from the enlargement setting switch.

The DMA controller sequentially reads the image data written in the bit map memory and outputs it to the parallel-serial converter.

The parallel-serial converter converts the image data from the DMA control unit into serial data and outputs the converted data to the printing mechanism unit in synchronization with the synchronization signal from the enlargement processing unit.

The printing mechanism section prints the image data from the parallel-serial converter.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the embodiment shown in FIG. 1, a bitmap memory 40 for storing image data, an enlargement setting switch 60 for setting an enlargement value n, and a sync signal corresponding to the enlargement value set by the enlargement setting switch 60 are provided. Enlargement processing unit 10 for outputting
And a DMA control unit 30 for sequentially reading the image data written in the bitmap memory 40, and a DMA control unit 30.
A parallel-to-serial converter 20 that converts the image data from the serial data into serial data and outputs the converted data in synchronization with the synchronization signal from the enlargement processing unit 10, and a printing mechanism unit that prints the image data from the parallel-serial converter 20. And 50.

Here, the enlargement processing section 10 includes a clock generator 17 for generating a rectangular wave of a constant cycle, a frequency dividing circuit 18 for generating a 1 / n frequency synchronizing signal from the rectangular wave of the clock generator 17, and a clock. A selector 19 which selects either the rectangular wave from the generator 17 or the synchronizing signal from the frequency dividing circuit 18 and outputs it to the parallel-serial converter 20, and the address counter 16 which holds the address value M of the bitmap memory 40 being executed. And a byte counter 12 that subtracts the value n for each reading in m-byte units (device-dependent), and a constant obtained by dividing the number of bytes for one scan line predetermined for each device by m, that is, one scan line. Count register 13 for holding the access count L necessary for reading the data, and data reading for one scan line A scan counter 14 only subtracts the value b each time ended, the last address of a page of data written in the bit map memory 40 the value E
Line counter 15 that holds the, and enlargement setting switch 6
The video control unit 11 controls the selector 19 based on the enlargement value set at 0.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

[0025]. When the value n of the enlargement setting switch 60 is set (S10 of FIG. 2), the video control unit 11 sets the enlargement value n to the value b of the scan counter 14 (S30 of FIG. 2).

Further, the video control unit 11 sets the value a of the byte counter 12 to the value L of the count register 13 (S30 in FIG. 2).

The video control unit 11 also includes a frequency dividing circuit 18
Is set to be 1 / n of the output frequency of the clock generator 17.

.. When the image data is sent, the video control unit 11 stores it in the bitmap memory 40 (S20 in FIG. 2).

.. The DMA unit 30 sequentially reads the image data stored in the bitmap memory 40 from the address M indicated by the address counter 16 in units of m bytes (S40 in FIG. 2). Here, the value of m is device-dependent.

Then, the DMA section 30 sends the image data read from the bit map memory 40 to the parallel-serial converter 20.

Further, the parallel-serial converter 20 is
The image data from the DAM unit 30 is converted into serial data, which is sent to the printing mechanism unit 50 in synchronization with the synchronization signal output from the selector 19.

Here, the selector 19 selects the clock signal directly input from the clock generator 17 in the case of normal printing which does not require enlargement processing, and selects the clock signal directly inputted from the clock generator 17 in the case of printing requiring enlargement processing. The 1 / n frequency synchronizing signal input from the frequency dividing circuit 18 is selected.

.. The video control unit 11 increments the value M of the address counter 16 each time the DMA unit 30 reads m bytes, and also the value a of the byte counter 12.
Is decremented (S50 in FIG. 2).

The above process is repeated until the value a of the byte counter 12 becomes 0 (S60 in FIG. 2).

When the value a of the byte counter 12 becomes 0 (S60 of FIG. 2), that is, when the data reading for one scan line is completed, the video control 11 checks the value b of the scan counter 14 (S70 of FIG. 2). ).

.. If the value b of the scan counter 14 is larger than 1, the video control unit 11 determines that the address counter 16
The value L of the count register 13 is subtracted from the value M of, and the value b of the scan counter 14 is decremented (S80 in FIG. 2).

Then, the process returns to the above process. By this processing, the same data for one scan line is read n times.

.. On the other hand, if the value b of the scan counter 14 is 1, the video control unit 11 determines that the line counter 15
The value E of is checked (S90 in FIG. 2).

That is, the video control unit 11 compares the values of the address counter 16 and the line counter 15 (S90 in FIG. 2). If the value E of the line counter 15 is larger, the value b of the scan counter 14 is compared. Is set to the enlargement value n, the value a of the byte counter 12 is set to the value L of the count register 13, and the process returns to the above.

On the other hand, when the value of the address counter M becomes equal to the value of the line counter 15, the processing of the video control unit 11 ends.

Further, the difference between when the normal synchronizing signal is input to the parallel-serial converter 20 and when the 1/2 frequency synchronizing signal is input will be described in detail with reference to FIG.

The parallel-to-serial converter 20 sends the image data dot by dot to the printing mechanism unit 50 with the rising or falling edge of the synchronizing signal as a trigger. At this time, one dot (1 bit) corresponds to one clock of the synchronizing signal and has a linear relationship with the width of the dot.

That is, when a 1/2 frequency clock is used as a trigger, since 1 dot corresponds to 1 clock, the width of 1 dot corresponds to 2 dots when a normal clock is input. .

When output in this way, it is synonymous with outputting 1 dot (1 bit) data twice by a normal clock signal, and a print result obtained by doubling the horizontal direction of 1 line data is obtained. can get.

That is, when a clock having a frequency of 1 / n is input, a print result obtained by horizontally enlarging one line of data by n times is obtained.

As described above, according to the present invention, since all the enlargement processing is performed only by the processing by hardware, the enlargement processing does not require a special time, and the enlargement printing can be performed in the same time as the normal printing processing. You can Further, since there is no part that depends on software, there is no exclusive use of the CPU, and the CPU can be used for other processing.

[0047]

Since the present invention is constructed and functions as described above, according to the present invention, all the enlargement / reduction processing can be performed only by the processing by hardware, which makes the enlargement / reduction processing special. It is possible to provide an excellent printer device which does not require time and which can reduce the load on the CPU and which has not been available in the past.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the embodiment of FIG.

FIG. 3 is a timing chart for explaining the operation of the embodiment of FIG.

FIG. 4 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 10 Enlargement Processing Section 11 Video Control Section 12 Byte Counter 13 Count Register 14 Scan Counter 15 Line Counter 16 Address Counter 17 Clock Generator 18 Frequency Divider 19 Selector 20 Parallel Serial Converter 30 DMA Control Section 40 Bitmap Memory 50 Printing Mechanism Section 60 Enlargement setting switch

Claims (2)

[Claims] 1. A bitmap memory for storing image data, an enlargement setting switch for setting an enlargement value, an enlargement processing section for outputting a synchronization signal corresponding to the enlargement value set by the enlargement setting switch, A DMA control unit for sequentially reading the image data written in the bitmap memory,
A parallel-serial converter that converts the image data from the DMA control unit into serial data and outputs the converted data in synchronization with the synchronization signal from the enlargement processing unit, and prints the image data from the parallel-serial converter. A printer device comprising a printing mechanism section. 2. The enlarging processing section includes a selector for selecting a sync signal to be output to the parallel-to-serial converter, a frequency divider circuit for generating a sync signal of 1 / n frequency from a predetermined sync signal, and a frequency divider circuit for dividing the sync signal. 2. The printer device according to claim 1, further comprising a video control unit for instructing the peripheral circuit to output a synchronization signal corresponding to the enlargement value n.