JP2000103113A - Image recorder and memory medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress increasing of manufacturing cost due to raising of a speed of an extracting operation in an image recorder. SOLUTION: This image recorder comprises an optical beam output circuit 27 that outputs an optical beam for forming an electrostatic latent image in accordance with recording data, a buffer memory 22 that stores one line of recording data to be supplied to the optical beam output circuit 27 and an extracting circuit 21 that forms the next line of recording data in accordance with command data supplied from an external device and one line of recording data to be supplied to the optical beam output circuit 27. The extracting circuit 21 forms the next line of recording data in accordance with the command data supplied from the external device and the present line of recording data, after the present line of data stored in the buffer memory 22 is supplied to the optical beam output circuit 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus used in a laser printer, for example, and a storage medium storing a program for controlling the image recording apparatus.

[0002]

2. Description of the Related Art Some image recording apparatuses include a decompression circuit for generating print data of the next line based on print data and command data of a current line. That is, the command data is equivalent to the compressed recording data, and efficiently indicates the difference between the recording data of the current line and the recording data of the next line in various predetermined expressions. By changing the recording data of the current line based on the above, the recording data of the next line can be generated.

Such a conventional image recording apparatus supplies the recording data of the current line read from the line memory to the light beam output device and also supplies the recording data of the current line to the decompression circuit. The decompression circuit generates the recording data of the next line based on the command data supplied from the outside.

[0004]

However, in the above-described conventional image recording apparatus, the recording data of the current line supplied to the light beam output device is supplied to the decompression circuit as it is, so that the decompression can be performed at a very high speed. Circuit is needed,
There was a problem that the circuit size of the decompression circuit became large and the manufacturing cost became expensive.

[0005] That is, the processing time of the decompression circuit greatly changes for each instruction content included in a plurality of command data. However, since the supply speed of the recording data to the light beam output device is always constant, the recording data is also supplied to the decompression circuit at a constant speed. As a result, it is necessary to match the processing speed for the instruction content with the longest processing time with the supply speed of the recording data, and the processing speed of the decompression circuit must be increased. Therefore, even though the average processing speed for decompressing one line of recording data does not need to be so high, a large-scale decompression circuit capable of performing parallel processing or the like must be provided for high speed. Instead, the production cost is increased.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above points, and has an image recording apparatus capable of suppressing an increase in manufacturing cost due to a high-speed decompression process, and an apparatus for controlling the image recording apparatus. It is an object of the present invention to provide a storage medium storing a program.

[0007]

According to another aspect of the present invention, there is provided an image recording apparatus, comprising: a light beam for outputting a light beam for forming an electrostatic latent image based on recording data; An output device, first storage means for storing one line of recording data to be supplied to the light beam output device, and command data supplied from the outside and one line of data to be supplied to the light beam output device. A decompression unit for generating the next one line of recording data based on the recording data.
After the recording data for one line stored in the storage means is supplied to the light beam output device, the recording for the next one line is performed based on the command data supplied from the outside and the recording data for one line. It was configured to generate data.

According to this image recording apparatus, the decompression means:
After the recording data for one line stored in the first storage means is supplied to the light beam output device, the data for the next one line is recorded based on the command data supplied from the outside and the recording data for one line. Since the recording data is generated, the reading speed of the recording data by the decompression means can be arbitrarily changed within one line, so that an increase in the manufacturing cost due to the speeding up of the decompression processing can be suppressed.

That is, since the supply of the recording data from the first storage means is not simultaneously performed to the light beam output device and the decompression means, the recording data is read at any time as the decompression processing by the decompression means progresses. Since only the total time required for decompressing one line of recording data is defined according to the recording speed, the processing speed of the decompression means does not need to be increased as in the conventional image recording apparatus. May be. In other words, when the processing speed of the decompression means is set to be the same as that of the conventional image recording apparatus, the recording speed can be improved.

The increase in the manufacturing cost due to the speeding up of the decompression process is, for example, when the decompression means is realized by hardware, the cost is increased due to the increase in the circuit scale for enabling the parallel processing. If the decompression means is realized by software, a faster CPU (centra
l This is an increase in costs associated with adopting a processing unit.

As the recording data, for example, bitmap data can be used.

As the light beam output device, for example, a laser device or a light emitting diode array can be used.

The first storage means is a RAM (random
access memory) can be used, but is not limited to this.

[0014] The decompression means may be realized by a logic circuit, or may be realized by a CPU that operates based on a predetermined program.

According to a second aspect of the present invention, there is provided the image recording apparatus as set forth in the first aspect, wherein the decompressing unit is configured to record one line stored in the first storage unit. After the data is supplied to the light beam output device, the next 1 based on the command data supplied from the outside and the recording data for one line stored in the first storage means.
Generate recording data for the line.

According to this image recording apparatus, in addition to the effect of the image recording apparatus according to the first aspect, the recording data of the current line stored in the first storage means is overwritten with the recording data of the next line. Therefore, only one line of storage means is required, and the manufacturing cost can be further reduced.

Furthermore, an image recording apparatus according to a third aspect of the present invention is the image recording apparatus according to the first aspect, wherein the second storage means for storing one line of recording data,
Storage control means for storing, in the second storage means, one line of recording data output from the storage means and supplied to the light beam output device, and the decompression means comprises command data supplied from the outside. And 1 stored in the second storage means.
The next one line of print data is generated based on the line of print data.

According to this image recording apparatus, in addition to the effect of the image recording apparatus according to the first aspect, since the recording data of the current line remains in the first storage means, when recording the next line, refer to two lines. Can be smoothed.

As the second storage means, a RAM can be used, but it is not limited to this.

[0020] The storage control means may be realized by a logic circuit or a CP operating based on a predetermined program.
It may be realized by U.

An image recording apparatus according to a fourth aspect of the present invention is the image recording apparatus according to the third aspect, wherein
Storage means, decompression means, second storage means, and storage control means are realized by one integrated circuit.
Storage means and the second storage means are realized by mutually different areas of one semiconductor memory built in the integrated circuit.

According to this image recording apparatus, in addition to the effects of the image recording apparatus according to claim 3, the apparatus can be downsized.
The weight can be reduced.

According to a fifth aspect of the present invention, there is provided the image recording apparatus according to any one of the first to fourth aspects, wherein the light beam output from the light beam output device is one. An electrostatic latent image is formed by scanning this one laser beam.

According to this image recording apparatus, in addition to the effect of the image recording apparatus according to any one of the first to fourth aspects, the time from when the scanning of the current line is completed to when the scanning of the next line is started is started. In the meantime, it is not necessary that all the recording data of the next line be decompressed, and the decompression of the part supplied to the light beam output device with the progress of scanning may be completed. Processing speed can be further reduced.

According to the storage medium of the present invention, a light beam output device for outputting a light beam for forming an electrostatic latent image based on recording data, and a light beam output device for supplying the light beam to the light beam output device. A storage medium storing a program for controlling an image recording apparatus having first storage means for storing print data for one line of the one line, the one storage medium for one line stored in the first storage means. Including a decompression program for generating recording data for the next one line based on command data supplied from the outside and recording data for one line after the recording data for the first line is supplied to the light beam output device Is stored.

According to this storage medium, the operation of the image recording apparatus according to the first aspect can be realized by operating the CPU based on the stored program.

The storage medium may be a nonvolatile semiconductor memory, but is not limited thereto. For example, a volatile semiconductor memory backed up by a battery and a CD-ROM
A ROM (compact disk read only memory), a flexible disk, or a hard disk may be used.

[0028]

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 circuit block diagram of a multifunctional peripheral device (hereinafter, referred to as "MFD") provided with an image recording apparatus according to the present invention. The MFD includes a CPU 1, an NCU 2,
RAM 3, modem 4, ROM 5, EEPROM 6, gate array 7, codec 8, DMAC 9, PC interface 10, reading unit 11, recording unit 12, operation unit 1.
3 and a display unit 14. CPU1, NCU
2, RAM 3, modem 4, ROM 5, EEPROM 6,
Gate array 7, codec 8, DMAC 9, and P
The C interfaces 10 are mutually connected by a bus line 15. The bus line 15 includes an address bus, a data bus, and a control signal line. Gate array 7
Is connected to the reading unit 11, the recording unit 12, the operation unit 13, and the display unit 14. A telephone line 16 as an example of a communication line and a modem 4 are connected to the NCU 2. A personal computer (not shown) is connected to the PC interface 10.

The MFD has a plurality of functions such as a facsimile communication function, a copy function, an image scanner function, and a printer function. The facsimile communication function can be exhibited by the MFD alone, and also can be exhibited in cooperation with the personal computer.

The CPU 1 controls the entire MFD.

An NCU (network control unit) 2 is connected to the telephone line 16 and performs network control.

The RAM 3 stores various data such as command data from a personal computer, and has a CPU
1. Provide a work area.

The modem 4 modulates transmission data and demodulates received data.

A ROM (read only memory) 5 stores various programs and initial setting values.

An EEPROM (electrically erasable an
d programmable read only memory) 6 stores various flags such as an initial value flag, a plurality of destination telephone numbers for so-called one-touch dialing, abbreviated dialing, etc., or a communication history.

The gate array 7 includes a reading unit 11, a recording unit 1,
2. Control the communication between the operation unit 13, the display unit 14, and the CPU 1.

The codec 8 encodes transmission data and decodes reception data.

DMAC (direct memory access control)
er) 9 controls writing and reading of data to and from the RAM 3.

A PC (personal computer) interface 10 controls communication between the CPU 1 and the personal computer.

The reading section 11 includes a light source, an image sensor, a document feed motor, and the like, reads a document, and outputs an analog image signal.

The recording unit 12 includes an electrophotographic printing unit using a laser beam, and records an image based on recording data on recording paper.

The operation unit 13 allows the user to perform a mode switching operation,
It is for performing operation instruction operation and various setting or registration operation, and is composed of a group of key switches, etc.
Outputs a signal according to the operation of the user.

The display unit 14 is an LCD (liquid crystal d)
and various displays are controlled by the CPU 1.

FIG. 2 is a circuit block diagram of a main part of the recording unit 12. The recording unit 12 includes a decompression circuit 21, a buffer memory 22, read circuits 23 and 24, and write circuits 25 and 26.
And a light beam output circuit 27. Decompression circuit 2
1. The buffer memory 22, the read circuits 23 and 24, and the write circuits 25 and 26 are ASIC (application specif.
ic integrated circuit) 31 in one semiconductor chip.

The decompression circuit 21 is stored in the RAM 3 from the personal computer via the PC interface 10, and is transferred from the RAM 3 to the gate array 7 by the DMAC 9.
, And print data of the next line is generated based on the command data supplied via the buffer memory 22 and the print data of the current line stored in the buffer memory 22. That is, the command data is data for instructing how to change the recording data of the current line, and by changing the recording data of the current line according to the instruction, the recording data of the next line can be obtained. . Note that the recording data is bitmap data.

The buffer memory 22 is an SRAM (static
It is realized by random access memory, and stores the recording data of the current line and the recording data of the next line.

After the read circuit 24 supplies all the recording data of the current line from the buffer memory 22 to the light beam output circuit 27, the read circuit 23
, And reads out the recording data of the current line and supplies it to the decompression circuit 21.

The read circuit 24 reads the record data of the current line from the buffer memory 22 and supplies the read data to the light beam output circuit 27.

The writing circuit 25 writes the recording data of the next line generated by the decompression circuit 21 into the buffer memory 22.

The writing circuit 26 is read from the buffer memory 22 by the reading circuit 24 and
The recording data of the current line supplied to the
Write to 2.

The light beam output circuit 27 outputs one light beam which is turned on / off based on the recording data supplied via the read circuit 24.

FIG. 3 is a conceptual explanatory diagram of the decompression operation by the decompression circuit 21, and FIG. 4 is a timing chart of the decompression operation by the decompression circuit 21. The operation of the recording unit 12 will be described with reference to FIGS. Will be described. Note that the line memories 22a and 22b are
This is realized by two different areas. 4A shows a horizontal synchronizing signal based on a BD signal obtained by detecting a laser beam from a light beam output circuit 27 at a predetermined position, and FIG. The read recording signal of the current line, (c) is the recording signal of the next line decompressed by the decompression circuit 21.

Now, assuming that the recording data stored in the line memory 22a is the recording data of the current line,
The recording data of the current line is sequentially read out by the reading circuit 24 as shown in FIG. 4B after a predetermined time has elapsed from the rise of the horizontal synchronizing signal shown in FIG. 27. As a result, the light beam output circuit 27 outputs a laser beam that is turned on / off according to the supplied recording data of the current line, and the laser beam is irradiated on the surface of the photosensitive drum while being scanned by a polygon mirror or the like. Then, an electrostatic latent image corresponding to the recording data is formed on the surface of the photosensitive drum. On the other hand, the recording data of the current line read from the line memory 22a by the read circuit
To the line memory 22b by the writing circuit 26.
Is written to. That is, the recording data of the current line stored in the line memory 22a is stored in the line memory 22a.
b.

At the same time that the reading circuit 24 completes reading the recording data of the current line from the line memory 22a, the command data of the next line stored in the RAM 3 from the personal computer via the PC interface 10 is gated by the DMAC 9. The data is supplied to the decompression circuit 21 via the array 7. Thus, the decompression circuit 2
1 requests the read circuit 23 for recording data necessary for decompression. As a result, the readout circuit 23 reads out a necessary portion of the recording data of the current line copied to the line memory 22b and supplies it to the decompression circuit 21. Thus, the decompression circuit 2
1 changes the recording data of the current line based on the instruction of the command data, generates the recording data of the next line, and supplies it to the writing circuit 25. Thereby, the writing circuit 2
5 writes the recording data of the next line from the decompression circuit 21 to the line memory 22b.

Similarly, the decompression circuit 21 sequentially requests the readout circuit 23 for the recording data of the current line necessary for decompression, and accordingly the recording data of the current line read out by the readout circuit 23 is sequentially decompressed. Then, the recording data of the next line is stored in the line memory 22b.

The recording data stored in the line memory 22b is read by the reading circuit 24 as the recording data of the current line, and is supplied to the light beam output circuit 27. That is, the line memory 22a stores the recording data of the current line, the line memory 22b stores the recording data of the next line, and the line memory 22b stores the recording data of the current line, and stores the next line in the line memory 22a. The state in which the recording data is stored alternates with each other for each recording of one line. Therefore, it is necessary to change the connection state of the circuit shown in FIG. 3 every time one line is recorded, but actually, the access to the buffer memory 22 by the read circuits 23 and 24 and the write circuits 25 and 26 in FIG. Only the address changes.

At this time, as shown in FIG. 4C, when the decompression circuit 21 decompresses the recording data of the next line, the recording data of the next line is read by the reading circuit 24 as the recording data of the current line. It is not necessary to be before the time when the reading is started, and the individual bits of the recording data
It is sufficient that the data is written to the buffer memory 22 by the writing circuit 25 before the data is actually read from the buffer memory 22 by the step S4.

In the above embodiment, two line memories 22a and 22b are formed by the buffer memory 22, but a single line memory may be used for decompression. That is, as shown in FIG. 5, one line memory 22c is constituted by the buffer memory 22, and after the read data is read from the line memory 22c by the read circuit 24, the line memory 22c is read by the read circuit 23. And sequentially reads out the recording data of the current line stored in
The recording data of the next line generated by the decompression circuit 21 may be sequentially overwritten on the line memory 22c by the writing circuit 25.

In the above embodiment, the decompression circuit 21, the read circuits 23, 24, and the write circuits 25, 26
And the decompression means is realized by a logic circuit, but the decompression means may be realized by the CPU 1 operating based on a predetermined program stored in the ROM 5.

[0061]

As described above, according to the image recording apparatus of the first aspect of the present invention, the decompression means uses the recording data for one line stored in the first storage means as the light beam output device. After the data is supplied to the storage unit, the next one line of print data is generated based on the command data supplied from the outside and the one line of print data. Since it can be arbitrarily changed in the meantime, it is possible to suppress an increase in manufacturing cost due to an increase in the speed of the decompression process.

According to the image recording apparatus of the second aspect of the invention, in addition to the effect of the image recording apparatus of the first aspect, the recording data of the current line stored in the first storage means is stored. Since the recording data of the next line is overwritten, the storage means is sufficient for one line, and the manufacturing cost can be further reduced.

According to the image recording apparatus of the third aspect of the invention, in addition to the effect of the image recording apparatus of the first aspect, the recording data of the current line remains in the first storage means. When recording the next line, smoothing processing with reference to two lines can be performed.

According to the image recording apparatus of the invention described in claim 4, in addition to the effect of the image recording apparatus of claim 3, the apparatus can be reduced in size and weight.

Further, according to the image recording apparatus of the invention described in claim 5, in addition to the effect of the image recording apparatus according to any one of claims 1 to 4, in addition to the effect obtained by scanning the current line, It is not necessary that all the recording data of the next line be decompressed before the line scan is started, and the decompression of the portion supplied to the light beam output device as the scan progresses is completed. Therefore, the processing speed required for the decompression means can be further reduced.

According to the storage medium of the invention described in claim 6, the CPU based on the stored program.
The operation of the image recording apparatus according to claim 1 can be realized by operating.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of an MFD including an image recording apparatus according to the present invention.

FIG. 2 is a circuit block diagram of a main part of a recording unit provided in the MFD shown in FIG.

FIG. 3 is a conceptual explanatory diagram of a decompression operation by the decompression circuit shown in FIG. 2;

FIG. 4 is a timing chart of a decompression operation by the decompression circuit shown in FIG. 2;

FIG. 5 is a conceptual explanatory diagram of a decompression operation by a decompression circuit according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 3 RAM 5 ROM 9 DMAC 12 Recording part 21 Decompression circuit 22 Buffer memory 22a, 22b, 22c Line memory 31 ASIC

Claims (6)

[Claims] 1. A light beam output device for outputting a light beam for forming an electrostatic latent image based on print data, and a line for storing one line of print data to be supplied to the light beam output device. 1 storage means, and decompression means for generating recording data for the next one line based on command data supplied from the outside and recording data for one line to be supplied to the light beam output device. An image recording apparatus, wherein the decompression means includes command data supplied from outside after the one line of recording data stored in the first storage means is supplied to the light beam output device. An image recording apparatus, wherein the recording data for the next one line is generated based on the recording data for one line. 2. The method according to claim 1, wherein the decompressing unit is configured to supply command data supplied from outside after the recording data for one line stored in the first storage unit is supplied to the light beam output device. 2. The image recording apparatus according to claim 1, wherein the recording data for the next one line is generated based on the recording data for one line stored in one storage unit. 3. A second memory for storing print data for one line.
Storage means, and storage control means for storing the one line of recording data output from the first storage means and supplied to the light beam output device in the second storage means, 2. The decompression unit generates the next one line of print data based on command data supplied from the outside and the one line of print data stored in the second storage unit. 3. The image recording apparatus according to claim 1. 4. The first storage unit, the decompression unit, the second storage unit, and the storage control unit are realized by one integrated circuit, and the first storage unit and the second storage unit 4. The image recording apparatus according to claim 3, wherein said second storage means is realized by mutually different areas of one semiconductor memory built in said integrated circuit. 5. The light beam output from the light beam output device is a single laser beam, and the single laser beam is scanned to form an electrostatic latent image. 5. The image recording apparatus according to any one of 4. 6. A light beam output device for outputting a light beam for forming an electrostatic latent image based on recording data, and a first line of recording data for one line to be supplied to the light beam output device. A storage medium storing a program for controlling an image recording apparatus having one storage unit, wherein the one line of recording data stored in the first storage unit is stored in the light beam output device. After being supplied to
A storage medium storing a program including a decompression program for generating the next one line of print data based on command data supplied from the outside and the one line of print data.