JPH082021A - Page printer device - Google Patents

Abstract

PURPOSE:To provide a page printer device capable of preventing the occurrence of overrunning errors and also preventing cost from being increased. CONSTITUTION:The device includes a receiving buffer 34 adapted to store printing data from the host computer, a raster buffer 15 to have printing image data stored therein among printing data taken out of the receiving buffer 34, and a printing part 16 wherein the printing image data taken out of the raster buffer 15 is transmitted as raster outputted data DATA, and printing is effected relative to the raster outputted data DATA. Also, it includes means for determining the capacity of the receiving buffer 34, and means for setting printing speed corresponding to the capacity of the receiving buffer 34. In this instance, when the capacity of the receiving buffer 34 is small, printing speed is set low, and when the capacity of the receiving buffer 34 is large, printing speed is set high. As a result, printing data within the receiving buffer 34 never wants.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a page printer device.

[0002]

2. Description of the Related Art Conventionally, in a page printer connected to a host computer, a page description language typified by PostScript language for drawing straight lines and curves that form the outlines of font data, figures, characters, etc. There is a dumb printer that prints only with print image data without using such as.

2 is a block diagram of a conventional page printer, FIG. 3 is a diagram showing a printing operation of the conventional page printer, FIG. 4 is a time chart of the conventional page printer, and FIG. 5 is a conventional page printer. 3 is a flowchart showing the operation of FIG. In the figure, 11 is a CPU,
The CPU 11 controls the entire page printer device according to a program stored in the program ROM 12. The CPU 11 receives an ESC command such as paper width designation and print image data from a host computer (not shown) via the host computer interface 13, and writes the print image data in the reception buffer 14. The program ROM 12 has a print speed setting table 12a for setting the print speed to 4 [PPM]. The reception buffer 14 has a capacity of 512 [kbytes].

Then, the reception buffer 14 becomes full, or reception of print data for one page is completed,
Upon receiving the print start command from the host computer, the CPU 11 extracts the print data from the reception buffer 14 and writes it in the raster buffer 15. Usually, since the print data is subjected to compression processing such as TIFF and delta low, the print data is decompressed and written in the raster buffer 15.

Next, when the CPU 11 receives a print start command from the host computer, it takes out print image data from the raster buffer 15 and uses the print image data as raster output data DATA in the printing unit 16.
Transfer to. The printing unit 16 prints the image on the paper P along the raster line L in the order shown in FIG. In this case, the scan timing generation circuit 17 uses the timer 18
The page synchronization clock CLK1, the line synchronization clock CLK2, and the dot timing clock CLK3 are generated based on the clocking by. Therefore, the timer 1
Reference numeral 8 generates a print timing signal SG1 and sends the print timing signal SG1 to the scan timing generation circuit 17.

Then, the CPU 11 synchronizes with the dot timing clock CLK3 and the raster buffer 15
The print image data of the raster line L is extracted from each dot. At this time, the dot timing clock C
The LK3 is sent to the raster buffer 15 and also to the printing unit 16, and transfers the print image data extracted from the raster buffer 15 to the printing unit 16 as raster output data DATA.

When the transfer of the raster output data DATA for one raster line is completed, the line synchronization clock CLK2 is sent to the printing section 16. Upon receiving the line synchronization clock CLK2, the printing unit 16 returns the raster scan position to the left end of the paper P at the movement timing T1 as shown in FIG. 4, and performs line feed for one raster line. Further, when scanning of all raster lines in one page is completed, the page synchronization clock CLK1 is sent to the printing unit 16. When the printing section 16 receives the page synchronization clock CLK1, it ejects the paper P at the intake / ejection timing T2 and inhales the next paper P.

By the way, the scan timing generation circuit 17 is provided with the CPU 11 each time the raster output data DATA of a bit length is taken out from the raster buffer 15.
To the raster buffer 15 is issued. The print timing signal SG1 is generated in correspondence with the print speed of 4 [PPM] set by the data of the print speed setting table 12a,
As described above, it is sent to the scan timing generation circuit 17 and also to the motor drive unit 19. Then, the motor drive unit 19 drives the drum motor 20 based on the print timing signal SG1. In addition,
DB is a data bus and AB is an address bus. Step S1 The CPU 11 takes out the print data from the reception buffer 14. In step S2, it is determined whether the fetched print data is a command for designating the paper width or the like. If the command is a command for specifying the paper width, the process proceeds to step S3. Step S3 Various registers are set according to the contents of the command, and the process returns to step S1. In step S4, it is determined whether the fetched print data is a print start command. If it is the print start command, the process proceeds to step S5. If it is not the print start command, the process proceeds to step S6. In step S5, the print image data is fetched from the raster buffer 15 and the raster output data D
The data is transferred to the printing unit 16 as ATA to start printing. Step S6: The extracted print data is judged to be print image data, and the print image data is written in the raster buffer 15.

[0009]

However, in the above-described conventional page printer device, when printing a high-density print image, a pattern which is difficult to perform compression processing on print data, or the like, the host computer interface 13 is used. The time required for the processing in 1 becomes long, and the amount of print data extracted from the reception buffer 14 and written to the raster buffer 15 becomes larger than the amount of print data written to the reception buffer 14 per unit time. In this case, the print data in the receive buffer 14 becomes insufficient, resulting in an overrun error.

Next, another conventional page printer device will be described. FIG. 6 is a block diagram of another conventional page printer. It should be noted that the same components as those in FIG. 2 are denoted by the same reference numerals and the description thereof will be omitted. In this case, the reception buffer 24 has 4 [Mbyte].
It has a capacity of 4 times and can store print data four times as large as that of the page printer apparatus shown in FIG.

The program ROM 12 has a print speed setting table 1 for setting the print speed to 4 [PPM].
2a, and the print timing signal SG1 is 4 set by the data of the print speed setting table 12a.
It is generated corresponding to the printing speed of [PPM]. Therefore, since the capacity of the reception buffer 24 is large with respect to the printing speed, it is possible to prevent the occurrence of an overrun error by starting printing after writing a sufficient amount of print data in the reception buffer 24. .

However, the reception buffer 24 having a large capacity
If you use, the cost will be high. The present invention
It is an object of the present invention to provide a page printer device that solves the problems of the conventional page printer device, prevents an overrun error from occurring, and prevents an increase in cost.

[0013]

Therefore, in the page printer apparatus of the present invention, a reception buffer in which print data from the host computer is stored, and print image data out of the print data extracted from the reception buffer. Is stored in the raster buffer, and the print image data extracted from the raster buffer is transferred as raster output data, and the printing unit prints the raster output data.

Further, it has means for judging the capacity of the receiving buffer and means for setting a printing speed corresponding to the capacity of the receiving buffer. Further, in another page printer apparatus of the present invention, a reception buffer in which print data from the host computer is stored, a raster buffer in which print image data of the print data extracted from the reception buffer is stored, The print image data fetched from the raster buffer is transferred as raster output data, and the printing unit prints the raster output data.

Further, it has means for reading the compression rate of the compression command in the print data and means for setting the printing speed corresponding to the compression rate.

[0016]

According to the present invention, as described above, in the page printer device, the reception buffer for storing the print data from the host computer and the print image data of the print data extracted from the reception buffer are stored. And a print unit that transfers the print image data extracted from the raster buffer as raster output data and prints the raster output data.

In this case, the print data transmitted from the host computer is received and written in the reception buffer. Subsequently, it is determined whether the print data fetched from the reception buffer is an ESC command or print image data, and if it is print image data, it is written in the raster buffer. The print image data extracted from the raster buffer is transferred to the printing unit as raster output data, and the raster output data is printed by the printing unit.

Then, it has means for judging the capacity of the receiving buffer and means for setting a printing speed corresponding to the capacity of the receiving buffer. Therefore, if the capacity of the receiving buffer is small, the printing speed is set low, and if the capacity of the receiving buffer is large, the printing speed is set high. Also,
In another page printer apparatus of the present invention, a reception buffer in which print data from the host computer is stored, a raster buffer in which print image data of the print data extracted from the reception buffer is stored,
The print image data fetched from the raster buffer is transferred as raster output data, and the printing unit prints the raster output data.

In this case, the print data transmitted from the host computer is received and written in the reception buffer. Subsequently, it is determined whether the print data fetched from the reception buffer is an ESC command or print image data, and if it is print image data, it is written in the raster buffer. The print image data extracted from the raster buffer is transferred to the printing unit as raster output data, and the raster output data is printed by the printing unit.

Then, it has means for reading the compression rate of the compression command in the print data and means for setting the printing speed corresponding to the compression rate. Therefore, when the compression rate is high, the printing speed is set high, and when the compression rate is low, the printing speed is set low.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a block diagram of a page printer device according to the first embodiment of the present invention, and FIG. 7 is a diagram showing the structure of a receiving buffer according to the first embodiment of the present invention.
FIG. 8 is a flow chart showing the operation of the page printer device according to the first embodiment of the present invention.

In the figure, 11 is a CPU, and the CP
The U11 controls the entire page printer apparatus by a program stored in the program ROM 32. The CPU 11 is a host computer interface 13
Via the host computer (not shown) to receive the ESC command such as paper width and print image data,
It is stored in the reception buffer 34.

In this case, the program ROM 32 is
A printing speed setting table 32a for setting the printing speed to 2 [PPM], a printing speed setting table 32b for setting the printing speed to 4 [PPM], and a printing speed of 6 [PP
The printing speed setting table 32c and the like for setting to [M]. The reception buffer 34 is composed of a RAM, and the capacity is set according to the density, pattern, etc. of the print image.

When the page printer is powered on (not shown), the receiving buffer 34 shown in FIG.
In which memory area on the memory map
It is determined according to the flowchart of FIG. Here, in the reception buffer 34, 1 [M
The case where a RAM of [byte] is installed will be described. Step S11 Last address F of memory area B
Data (eg, AAH) is written to FFFFH. Step S12 Final address of memory area B FFFFF
Read data from H. In step S13, it is determined whether the written data and the read data are equal. If they are equal, the process proceeds to step S15, and if they are not equal, the process proceeds to step S14. Step S14 Since it can be seen that the RAM is not mounted in the memory area B, R
AM is mounted in the memory area A, and the reception buffer 3
It is judged that the capacity of 4 is 512 [kbyte], and 2
The printing speed flag of [PPM] is set. Step S
15 Write data (for example, 55H) to the final address 1FFFFFH of the memory area C. Step S16
Data is read from the final address 1FFFFFH of the memory area C. In step S17, it is determined whether the written data and the read data are the same. If they are equal, go to step S19. If they are not equal, go to step S19.
Proceed to 18. Step S18 RAM in the memory area C
Since it can be seen that the RAM is not mounted, the RAM is mounted in the memory area B and the capacity of the reception buffer 34 is 1
When it is determined that the printing speed flag is [Mbyte], the printing speed flag of 4 [PPM] is set. Step S19 Memory area D
Data at the final address 3FFFFFH (for example, 3C
Write H). In step S20, the data is read from the final address 3FFFFFH of the memory area D. In step S21, it is determined whether the written data and the read data are equal. If they are equal, step S
23, if not equal, go to step S22. Step S22 Since it can be seen that the RAM is not mounted in the memory area D, it is determined that the RAM is mounted in the memory area C and the capacity of the reception buffer 34 is 2 [Mbyte], and 6 [PPM] is determined. Set the print speed flag. Step S23 Since it can be seen that the RAM is mounted in the memory area D, it is judged that the capacity of the receiving buffer 34 is 4 [Mbyte], and the printing speed flag of 8 [PPM] is set.

Next, the CPU 11 refers to the print speed flag and makes the CPU 1 correspond to the print speed flag in advance.
The load value stored in 1 is read and the load value is set in the timer 38. The timer 38 generates a print timing signal SG2 corresponding to the load value.
When the timer 38 is reloaded, the print timing signal SG2 is output to the scan timing generation circuit 17
And is also sent to the motor drive unit 19.

The structure of print data from the host computer is such that print image data follows a command such as paper width designation. Then, when the reception buffer 34 becomes full, or when the reception of the print data for one page is completed and the print start command is received from the host computer, the CPU 11 takes out the print data from the reception buffer 34 and outputs it to the raster buffer. Write to 15. Usually, since the print data is subjected to compression processing such as TIFF and delta low, the print data is decompressed and written in the raster buffer 15.

Next, when the CPU 11 receives a print start command from the host computer, it takes out print image data from the raster buffer 15 and uses the print image data as raster output data DATA in the printing unit 16.
Transfer to. The printing unit 16 prints an image on the paper P along the raster line L (see FIG. 3). In this case, the scan timing generation circuit 17 generates a page synchronization clock CLK1, a line synchronization clock CLK2 and a dot timing clock CLK3 based on the print timing signal SG2 from the timer 38.

Then, the CPU 11 synchronizes with the dot timing clock CLK3 and the raster buffer 15
The print image data of the raster line L is extracted from each dot. At this time, the dot timing clock C
The LK3 is sent to the raster buffer 15 and also to the printing unit 16, and transfers the print image data extracted from the raster buffer 15 to the printing unit 16 as raster output data DATA.

When the transfer of the raster output data DATA for one raster line is completed, the line synchronization clock CLK2 is sent to the printing section 16. When the printing section 16 receives the line synchronization clock CLK2, it moves at the timing T
In 1 (see FIG. 4), the raster scan position is returned to the left end of the paper P, and line feed for one raster line is performed. further,
After scanning all raster lines in one page,
The page synchronization clock CLK1 is sent to the printing unit 16.
When the printing section 16 receives the page synchronization clock CLK1, it ejects the paper P at the intake / ejection timing T2 and inhales the next paper P.

By the way, the scan timing generation circuit 17 is provided with the CPU 11 each time the raster output data DATA for the bit length is taken out from the raster buffer 15.
To the raster buffer 15 is issued. In this case, even if the compression rate of the print data is low, the printing speed can be set low, so that an overrun error can be prevented from occurring.

Further, the print timing signal SG2 is
It is generated corresponding to the print speed set by the data of the print speed setting table 32a, and is sent to the scan timing generation circuit 17 and the motor drive unit 19 as described above. Then, the motor drive unit 19 drives the drum motor 20 based on the print timing signal SG2. DB is a data bus and AB is an address bus.

As described above, since the print timing signal SG2 is changed according to the capacity of the receiving buffer 34 and the printing speed is selected, an overrun error is prevented even if the capacity of the receiving buffer 34 is small. Can be prevented. Next, a second embodiment of the present invention will be described. FIG. 9 is a block diagram of a page printer apparatus according to the second embodiment of the present invention, and FIG. 10 is a flow chart showing the operation of the page printer apparatus according to the second embodiment of the present invention. Note that FIG. 1 is referred to for the same structure as FIG. 1, and the description thereof is omitted.

In this case, the printing speed is changed according to the compression rate of the print data. Therefore, before transmitting the print data to the page printer by a host computer (not shown), a compression ratio command indicating the compression ratio is added to the command such as the paper width designation and the print image data. The configuration of the print data from the host computer is such that a command such as a paper width designation is followed by a compression ratio command, and further print image data. The compression rate command has a unique configuration such as ESC ^ Pn (n is the compression rate). Step S31 The CPU 11 uses the reception buffer 3
The print data is extracted from 4. In step S32, it is determined whether the fetched print data is a normal command for specifying the paper width. If the command is a normal command for specifying the paper width, the process proceeds to step S33. If it is not a normal command for specifying the paper width, the process proceeds to step S34. Step S33 Various registers are set according to the contents of the command, and the process returns to step S31. Step S34
It is determined whether the extracted print data is a compression rate command. If it is a compression ratio command, step S
If it is not the compression rate command, the process proceeds to step S37. Step S35 Based on the compression rate n of the compression rate command, the print speed setting tables 32a, 32b, ... In the program ROM 32 are referred to, and the print speed corresponding to the compression rate n is set. In this case, when the compression rate n is high, the printing speed is set high, and when the compression rate n is low, the printing speed is set low.

The program ROM 32 has a print speed setting table 3 for setting the print speed to 2 [PPM].
2a, a printing speed setting table 32b for setting the printing speed to 4 [PPM], a printing speed setting table 32c for setting the printing speed to 6 [PPM], and the like. Step S36 When the print speed setting tables 32a, 32b, ... Corresponding to the print speed are selected, the data values of the print speed setting tables 32a, 32b ,.
The data value is sent to the printing unit 16 and the motor driving unit 19 via the internal data bus DB, and is set in the counter of the scan timing generating circuit 17. In step S37, it is determined whether the print start command has been taken out. If it is a print start command, step S38 is performed. If it is not a print start command, step S38.
Proceed to 39. In step S38, the print image data is extracted from the raster buffer 15 and the raster output data DA
The TA is sent to the printing unit 16 to start printing. Step S39 It is judged that the fetched print data is print image data, and the print image data is written in the raster buffer 15.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and they are not excluded from the scope of the present invention.

[0036]

As described in detail above, according to the present invention, in the page printer device, of the reception buffer in which the print data from the host computer is stored and the print data extracted from the reception buffer, Of the print image data is stored, and the print image data extracted from the raster buffer is transferred as raster output data, and the printing unit prints the raster output data.

Then, it has means for judging the capacity of the reception buffer and means for setting a printing speed corresponding to the capacity of the reception buffer. In this case, the printing speed is set low when the capacity of the reception buffer is small, and the printing speed is set high when the capacity of the reception buffer is large. Therefore, from the amount of print data written in the receive buffer,
The amount of print data taken out from the reception buffer and written in the raster buffer does not increase. As a result, there is no shortage of print data in the receive buffer, and it is possible to prevent an overrun error from occurring.

Further, in another page printer of the present invention, a reception buffer for storing print data from the host computer and a raster for storing print image data of the print data extracted from the reception buffer. It has a buffer and a print unit for transferring the print image data taken out from the raster buffer as raster output data and printing the raster output data.

Further, it has means for reading the compression rate of the compression command in the print data and means for setting the printing speed corresponding to the compression rate. In this case, the printing speed is set high when the compression rate is high, and the printing speed is set low when the compression rate is low. Therefore, the amount of print data taken out from the reception buffer and written in the raster buffer does not become larger than the amount of print data written in the reception buffer. As a result, there is no shortage of print data in the receive buffer, and it is possible to prevent an overrun error from occurring.

[Brief description of drawings]

FIG. 1 is a block diagram of a page printer device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a conventional page printer device.

FIG. 3 is a diagram showing a printing operation of a conventional page printer device.

FIG. 4 is a time chart of a conventional page printer device.

FIG. 5 is a flowchart showing the operation of a conventional page printer device.

FIG. 6 is a block diagram of another conventional page printer device.

FIG. 7 is a diagram showing a structure of a reception buffer according to the first embodiment of the present invention.

FIG. 8 is a flowchart showing an operation of the page printer device according to the first embodiment of the present invention.

FIG. 9 is a block diagram of a page printer device according to a second embodiment of the present invention.

FIG. 10 is a flowchart showing the operation of the page printer device in the second embodiment of the present invention.

[Explanation of symbols]

 11 CPU 15 raster buffer 16 printing unit 32 program ROM 32a, 32b, 32c, ... Printing speed setting table DATA raster output data n compression rate

Claims (2)

[Claims] 1. A receiving buffer for storing print data from a host computer; (b) a raster buffer for storing print image data of print data retrieved from the receiving buffer; and (c) ) A print unit for transferring the print image data fetched from the raster buffer as raster output data and printing the raster output data; (d) means for determining the capacity of the reception buffer; and (e) the reception And a means for setting a printing speed corresponding to the capacity of the buffer. 2. A receiving buffer for storing print data from a host computer; (b) a raster buffer for storing print image data of print data retrieved from the receiving buffer; and (c) ) A printing unit for transferring the print image data fetched from the raster buffer as raster output data and printing the raster output data; and (d) a unit for reading a compression ratio of a compression command in the print data. (E) A page printer device having a means for setting a printing speed corresponding to the compression ratio.