JPH10275067A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the processing speed of data transfer which is carried out through a buffer memory. SOLUTION: The printer is equipped with a RAM 3 stored with print data for one band to be printed on a recording in a horizontal scanning direction in its buffer area divided into plural storage areas, a DMA controller 22 which writes the print data in the storage areas or reads the sequential print data out of the storage areas, and a print part 12 which prints the print data read out by the DMA controller 22 on the recording form; and the DMA controller 22 reads the print data out of one storage area of the buffer area and then erases the print data stored in the storage area immediately. The reading and writing from and to the storage area are repeated until a readout completion signal from the DMA controller 22 is received by a CPU 1.

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 printing print data via a buffer memory.

[0002]

2. Description of the Related Art Conventionally, various printing systems such as an impact system, a thermal system, and an ink jet system have been adopted as printing devices.
By moving a print head provided with a plurality of recording elements of these types in the main scanning direction, one print head
After printing for the band, characters are printed on the entire surface of the recording paper by repeating the printing operation of sub-scanning the recording paper for one band. Such a serial printing device has a CP which controls the entire device.
U, a buffer memory for storing print data for one band in a plurality of storage areas, a DMA controller for reading and writing print data for one band in the buffer memory, and printing read for each band by the DMA controller Drive the print head based on the data,
It is roughly constituted by a printing unit that prints one band at a time on recording paper.

In such a printing apparatus, a DMA controller writes one band of print data into a plurality of storage areas of a buffer memory, and then sequentially reads out the print data from the plurality of storage areas to a printing unit. Forward. When the print data is transferred to the printing unit, one band is printed on the recording paper by driving the storage element while moving the print head in the main scanning direction. When the printing operation for one band is completed, the recording paper is moved by one band in the sub-scanning direction,
Alternatively, after the CPU erases the print data in all the storage areas, the same print operation as described above is repeatedly performed.

[0004]

However, in the above-mentioned conventional printing apparatus, every time the printing operation for one band is completed, the print data in all the storage areas of the buffer memory is erased. Until erasure of the storage area is completed, writing of print data for the next band cannot be performed, and data transfer stagnates for each band, so that data transfer cannot be performed efficiently. there were.

[0005] The present invention has been proposed in view of the above points, and has as its object to provide a printing apparatus capable of improving the processing speed of data transfer performed via a buffer memory.

[0006]

According to a first aspect of the present invention, there is provided a printing apparatus comprising: a buffer for storing print data to be printed on a recording medium in a plurality of storage areas; A memory, writing means for writing print data to a plurality of storage areas of the buffer memory, reading means for sequentially reading print data from the plurality of storage areas of the buffer memory, and print data read by the reading means. A printing device for printing on the recording medium, wherein immediately after print data is read from one storage area of the buffer memory by the reading means, the print data of the one storage area is read. It has a sequential erasing means for erasing.

According to this printing apparatus, immediately after the print data is read from one storage area of the buffer memory, the print data of the one storage area is erased. Since the print data in almost all the storage areas has been erased and the next print data can be written immediately, the print data can be read and written to the buffer memory continuously, and Processing speed of the data transfer performed by the user can be improved. As a result, the printing speed can be improved.

A printing apparatus according to a second aspect of the present invention is the printing apparatus according to the first aspect, wherein the printing means moves the print data while moving in the main scanning direction with respect to the recording medium. And the buffer memory stores, in a plurality of storage areas, print data for one band printed by moving the printing means in the main scanning direction.

According to this printing apparatus, in addition to the effect of the printing apparatus according to claim 1, the printing means prints print data while moving in the main scanning direction with respect to the recording medium,
Since the buffer memory stores the print data for one band printed by the movement of the printing means in the main scanning direction in a plurality of storage areas, the reading and writing of the print data performed for each band is continuously performed without interruption. Can be done.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a block diagram of a facsimile apparatus provided with a printing apparatus according to the present invention. The facsimile apparatus includes a CPU 1, an NCU 2, a RAM 3, a modem 4, an R
An OM 5, an EEPROM 6, a gate array 7, a codec 8, and an interface 9 are provided. CPU
1, NCU2, RAM3, modem 4, ROM5, EEP
The ROM 6, the gate array 7, the codec 8, and the interface 9 are mutually connected by a bus line. The bus lines include an address bus, a data bus, and a control signal line. The gate array 7 includes a reading unit 1
1, a printing unit 12, an operation unit 13, and a display unit 14 are connected. A telephone line 15 is connected to the NCU 2 as an example of a communication line. A personal computer 31 can be connected to the interface 9.

The CPU 1 controls the entire facsimile machine. The NCU 2 is connected to the telephone line 15 and performs network control. The RAM 3 has a function as a buffer memory in data transfer, and stores various other data. The modem 4 performs modulation of transmission data and demodulation of reception data. The ROM 5 stores various programs executed by the CPU 1 and the like. EEPRO
M6 stores various data, flags, and the like. The gate array 7 functions as an input / output interface to the CPU 1 and performs a printing process and the like. The codec 8 performs encoding of transmission facsimile data and the like. The interface 9 is a personal computer 3
It becomes a contact point with peripheral devices such as 1. The reading unit 11 reads an image from a document using an image sensor or the like. The printing unit 12 has a print head such as an inkjet nozzle or the like in which recording elements are arranged, and a paper transport unit, and prints print data such as characters and figures on a recording paper as a recording medium. The operation unit 13 includes a key switch group and the like, and outputs a signal according to a user operation. The display unit 14 displays LC
D and the like, and are controlled by the CPU 1 to perform various displays.

FIG. 2 is a block diagram of a print processing unit realized by the gate array 7 in FIG. 1. The essential points of the printing apparatus according to the present invention will be described with reference to FIG. And interface 9
By securing a temporary storage area when transferring print data transferred via the printer to the printing unit 12, the print data is used as a buffer memory. The buffer area of the RAM 3 secures a capacity for storing one band of print data corresponding to a print width of a print head, which will be described later, and is divided into a plurality of storage areas specified by an address for each byte of print data. It has a structure. Reading and writing of print data in this storage area is performed by a DMA controller 22 described later. More specifically, a plurality of storage areas in the buffer area are allocated so as to store print data one byte at a time, and the entire storage area is configured to store one band of print data. That is, when the print head is scanned once, a predetermined number of pixels are printed from the recording element of the print head along the main scanning direction. This corresponds to one band of print data. Print data is stored in each storage area every 8 bits.

The CPU 1 controls transfer of print data based on a program stored in the ROM 5. Here, the actual reading and writing of the print data to and from the RAM 3 is directly performed by a DMA controller 22 described later.
The PU 1 controls the transfer operation of the print data for each band by the DMA controller 22. Specifically, when the CPU 1 receives a write start signal for one band of print data from the DMA controller 22, the bus line is opened to directly write data to the DMA controller 22, and the print data of one band is printed. Upon receiving the read completion signal, the DMA controller 2 closes the use of the bus line. The opening and closing of the bus line are performed at high speed based on the clock signal, and the operation of transferring the print data to the RAM 3 is also performed at high speed.

The print processing unit 16 in the gate array 7
Is schematically configured as a hard logic circuit having an I / F control unit 21, a DMA controller 22, and a print control unit 23. The CPU 1, the RAM 3, and the interface 9 are connected to the internal bus line of the print processing unit 16.

The I / F control unit 21 controls transfer of print data input from the personal computer 31 via the interface 9 to the DMA controller 22, for example.

The DMA controller 22 writes the print data transferred from the I / F control unit 21 into the buffer area of the RAM 3 for each band, reads the print data for each band, and reads the print data via the buffer area. The data transfer for each band is repeated at high speed. Specifically, DMA
When the controller 22 writes the print data for one band into the buffer area, the controller 22 writes the print data for one band in a plurality of storage areas while specifying the address of the storage area set in the buffer area. When the writing of the print data for one band is completed, the print data for one band is read from the storage area of the head address in a predetermined order. When reading print data from multiple storage areas,
Immediately after completing the data reading from one storage area, the A controller 22 erases the print data stored in the one storage area, and repeats reading / erasing the plurality of storage areas. The print data for one band is read. However, when the print data of, for example, 8 bits written in one storage area is 0 for all bits, the writing of the print data is not performed. Similarly, if all the bits of the 8-bit print data read from one storage area are 0, the storage area is not erased.

That is, the DMA controller 22 implements writing means for writing print data in a plurality of storage areas of the buffer memory and reading means for sequentially reading print data from the plurality of storage areas of the buffer memory. Further, immediately after the print data is read from one storage area of the buffer memory, a sequential erasing means for erasing the print data of the one storage area is realized.

Here, the erasing operation will be specifically described. Erasing data from the storage area is the same as writing white data in the storage area so that the recording element is not driven. An erase operation is executed by writing data expressed as "00H" in the assembly language, and reading / erasing in one storage area is performed almost simultaneously.

The print controller 23 includes a DMA controller 2
In step 2, the print head of the printing unit 12 is driven and controlled based on the print data read for each band. Specifically, when one band of print data is transferred from the DMA controller 22 in a predetermined order, the print control unit 23 drives the recording element while moving the print head in the main scanning direction with respect to the recording paper. As a result, pixels for one band corresponding to the print width of the print head are printed on the recording paper.
When printing of the print data for one band is completed, the print control unit 23 moves the recording paper in the sub-scanning direction by a not-shown conveying means, and repeats the printing for one band, so that characters or characters are printed on the entire recording paper. Pixels such as figures are printed. That is, the print control unit 23 and the print unit 12
Implements printing means for printing print data on a recording medium.

Next, the essential points of the operation of the printing apparatus thus configured will be described with reference to FIG.

FIG. 3 is a flowchart showing a printing operation of the printing apparatus according to the present invention. As shown in FIG.
First, when the printing process is started and print data is transferred to the I / F control unit 21 via the interface 9,
The CPU 1 requests the DMA controller 22 to fetch print data from the I / F control unit 21 (S
1).

The DMA controller 22, which has received the print data fetch request, fetches the print data from the I / F controller 21 and sends a write start signal to the buffer area of the RAM 3 to the CPU 1 (S2).

Upon receiving the write start signal, the CPU 1
The bus line is released to cause the controller 22 to directly write data to the RAM 3 (S3).

When the bus line is released by the CPU 1, D
The MA controller 22 continuously writes one band of print data in a plurality of storage areas of the buffer area while designating an address (S4).

When the writing is completed, the DMA controller 22 reads out the print data from the one storage area in which the data was written first, and transfers it to the print control unit 23 (S5).

Immediately after reading one print data, the DMA
The controller 22 deletes the print data stored in the one read storage area (S6). In this manner, the DMA controller 22 transfers the read data to the print control unit 23 while reading / erasing the print data from / to the plurality of storage areas in a predetermined order, and synchronously with the print control unit 2
Reference numeral 3 performs printing by driving the recording element while moving the print head in the main scanning direction with respect to the recording paper.

While print data is being read from the storage area by the DMA controller 22, the CPU 1
Determines whether or not print data has been read from all storage areas based on the read completion signal sent from the DMA controller 22 (S7).

When the read completion signal is received from the DMA controller 22 (S7: YES), the CPU 1 determines whether or not the print data for the next one band is waiting in the I / F control unit 21 by the I / F control. Judgment is made based on the capture request signal from the unit 21 (S8). When the capture request signal is received (S8: YES), the process returns to step S1 to capture the next waiting print data for one band. Yo D
Notify the MA controller 22.

In S8, if the capture request signal from the I / F control unit 21 is not received (S8: NO), that is, if the transfer of all the print data is completed, the CPU 1
Ends this main routine.

At S7, if the read completion signal is not received from the DMA controller 22 (S7: NO), S
Returning to step 5, the DMA controller 22 repeatedly reads out print data from one storage area while the bus line is opened by the CPU 1.

As described above, the data transfer by the DMA controller 22 from the start of the writing of the print data for one band in the buffer area to the completion of the reading is as follows.
Since almost no time is required for the erasing operation of the storage area, the operation can be continuously performed at high speed without interruption.

Therefore, according to this printing apparatus, immediately after the print data is read from one storage area of the buffer area, the print data of the one storage area is erased. At the time of completion, the print data in the storage area for one band has been erased, and the writing of the print data for the next one band can be immediately performed. RAM
3 can be read and written to and from the buffer area, and the processing speed of data transfer performed via the RAM 3 as a buffer memory can be improved.

Although the present embodiment has been described as a printing apparatus using an ink jet system, the present invention is not particularly limited to this, and a printing apparatus of a serial system having a print head of an impact system or a thermal system may be used. Good.

[0035]

As described above, according to the printing apparatus of the first aspect, immediately after the print data is read from one storage area of the buffer memory, the print data of the one storage area is read. Is erased, so that at the point of completion of reading from multiple storage areas, the print data in almost all storage areas has been erased, and the next print data can be written immediately. Data can be read from and written to the buffer memory, and the processing speed of data transfer performed via the buffer memory can be improved. As a result, the printing speed can be improved.

According to the printing apparatus of the present invention, in addition to the effect of the printing apparatus of the first aspect, the printing unit moves in the main scanning direction with respect to the recording medium. The print data is printed, and the buffer memory stores the print data for one band printed by moving the printing means in the main scanning direction in a plurality of storage areas. Reading and writing can be performed continuously without interruption.

[Brief description of the drawings]

FIG. 1 is a block diagram of a facsimile apparatus provided with a printing device according to the present invention.

FIG. 2 is a block diagram of a print processing unit provided in the facsimile apparatus shown in FIG.

FIG. 3 is a flowchart showing a printing operation of the printing apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 CPU 3 RAM 5 ROM 7 Gate array 9 Interface 12 Printing unit 16 Print processing unit 21 I / F control unit 22 DMA controller 23 Print control unit

Claims (2)

[Claims] A buffer memory for storing print data to be printed on a recording medium in a plurality of storage areas; a writing unit for writing print data in a plurality of storage areas of the buffer memory; A printing apparatus comprising: a reading unit that sequentially reads print data from a plurality of storage areas of a memory; and a printing unit that prints the print data read by the reading unit on the recording medium. Immediately after print data is read from one storage area of the buffer memory, the printing apparatus further comprises a sequential erasing means for erasing the print data of the one storage area. 2. The printing unit prints print data while moving in the main scanning direction on the recording medium, and the buffer memory stores one band printed by moving the printing unit in the main scanning direction. 2. The printing apparatus according to claim 1, wherein the print data for each minute is stored in a plurality of storage areas.