JPH0483664A - Printer device - Google Patents

Abstract

PURPOSE:To obtain a simple-construction and low-cost hardware by a method wherein a data transmission from an external memory device to a buffer means is conducted in synchronism with a data transmission from the buffer means to a printer engine. CONSTITUTION:After forming image data for one page to be outputted to a printer engine 20, a CPU 1 selects a color component to be outputted first out of image data stored in an external memory device 6 per color component Y, M, C, and B and outputs it to an external memory device control circuit 5 as a color = 0. When the color components to be stored in the external memory device 6 are stored under control, the CPU 1 assigns the color components Y, M, C, and B in this order in the external memory device 6 as a virtual memory space in the order of increasing address with the lowest one first. The CPU 1 outputs a print signal PRNT to the printer engine. The output of a vertical synchronizing signal VSREQ from the printer engine is waited. With the input of VSREQ, the CPU 1 instructs the external memory device control circuit 5 to transmit bit map image data to an FIFO 7.

Description

[Detailed description of the invention] The present invention relates to a printer device that is stored in and controlled by a printer.

[Conventional technology]

Page printers, typically laser beam printers, are far superior to conventional dot matrix type serial printers in terms of print quality, high speed printing, and low noise, and have rapidly developed in recent years. This page printer mainly includes an image forming controller that generates a page's worth of bitmap image data (hereinafter abbreviated as image data) from text and image print data output from a host computer, etc. It consists of a printer engine that exposes image data on a photoreceptor, and prints by a sequence of toner development, transfer to paper, and fixation.

The print data output from the host computer side is Po
The mainstream is written in a page description language such as 5tScript. For this reason, the former image forming controller generally has a hardware configuration including a high-speed microprocessor and one page of image memory (RAM). This image memory has a size of 1 MB if it is a binary (black and white) printer engine that supports A4 paper at 300 dpi.

The memory size of the above-mentioned image memory increases dramatically as resolution becomes higher, multivalued, and full color becomes available. Below, when calculating the memory size with the paper size fixed at A4, it is 4 MB for a 600 dpi misspace binary printer, 8 MB for a 300 dpi multilevel (8 bit width or 256 gradation) printer, and 8 MB for a 300 dpi full color (YMCB) printer. (each color component is 8 bits wide) 32 bits wide for printers
Requires M bytes. Such an increase in memory will lead to an extreme increase in the cost of the printer device.

There are two ways to reduce the cost increase mentioned above: (1) Reduce memory size using image compression; (2) Use inexpensive, large-capacity external storage devices such as hard disks as image memory. There is a method to use it as

[Problem to be solved by the invention]

However, in the former case, it is not only possible to compress image data (as in the case of the Po5tScript processing system, but also to generate new image data by recursively using the image data stored in the star image memory), and to print Sometimes it is necessary to read out image data from the image memory and decompress it to obtain complete bitmap image data, which poses the problem of an enormous amount of time required for compression and decompression. - Even when decompression is performed, there is a problem in that the control circuits are extremely complex.

In the latter case, by using conventional semiconductor memory such as DRAM and external storage devices such as hard disks, it is possible to reduce the unit memory cost to a few tens of minutes. per track (usually 8 to 2 per track)
(can store byte data in 0),
The time required to move the head to the track to be read or written (seek) is 5 to 15 ms.
It is technically very difficult to replace it as the image memory of a page printer because it is very long (ec) and the data transfer rate within the same track is not very fast (5 to IOM bits/sec). Ta. Furthermore, when an external storage device is used as an image memory from a microprocessor used in an image forming controller, virtual storage control becomes necessary, which causes the problem that the configuration of the image forming controller becomes complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a printer device that has a simple configuration and can perform high-speed printing at low cost.

[Means for Solving the Problems (and Effects)] In order to solve the above-mentioned conventional problems, the present invention provides an arrangement in which an inexpensive, large-capacity external storage device such as a hard disk is used as an image memory. F is used to control the output of image data from the storage device to the printer engine.
External storage control means that uses an IFO (FastIn Fast 0ut) memory or the like as a buffer means and transfers data from an external storage device to the buffer means based on a status signal output from the buffer means, and a synchronization signal output from a printer engine. An image forming controller for a color printer device, which has an image output control means for reading image data from a buffer means based on the above, and is capable of transferring data from an external storage device to the buffer means and transferring data from the buffer means to the printer engine. Since the transfer is performed asynchronously, the hardware configuration is simple and inexpensive.

In the above data transfer, the former starts data transfer when a status signal indicating the status of the buffer means itself is output when data is transferred from the buffer means to the printer engine, and transfers data for several lines or a predetermined memory size. is transferred at a time, approximately 10 Mbit/s.
It has a transfer speed of EC. The latter outputs image data from a buffer means to a printer engine based on a (horizontal) synchronization signal from the printer engine. For example, a full-color printer that prints one page per minute at 300 dpi (each color component of YMCB is 8 bits wide) The data is 1
(assuming that the data is output to the printer engine for each color allowance), the transfer rate is approximately 7.5 Mbit/sec. Therefore, the data transfer speed of the former is faster, and the image data can be outputted to the printer engine by the buffer means without causing any loss of image data.

Further, another embodiment of the present invention includes a plurality of external storage devices and buffer means corresponding one-to-one to the external storage devices,
Compatible with high-speed color printers.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1st
The figure is a system block diagram showing the image forming controller 21 of the color printer device of the present invention. 1 is a CPU that centrally controls the entire image forming controller, inputs print data or a print program output from a host computer etc. through the host I/F control circuit 4, and outputs image data to the printer engine 20 side. After the image data has been generated, printing is executed by communicating with the printer engine 20. 2
A bus control circuit performs bus arbitration between the CPUI and the system memory 3 or the host I/F control circuit 4 and the external storage device control circuit 5. The system memory 3 includes a code ROM 3a that controls the operation of the CPUI;
Font ROM that stores bitmap fonts or allant line fonts for text codes
3b and the CPUI uses it as a working area,
RA used as a buffer to temporarily store print data output from a host computer, etc., or to temporarily store image data to be stored on an external memory or device 6.
It is composed of M3C. 5 is an external storage device control circuit, during the period when the CPUI generates bitmap image data from print data, the CPUI or R
It controls the transfer of image data between A M3c and the external storage device 6, and after the image data has been generated in the external storage device 6 and printing has started, it is used as a printer output buffer from the external storage device 6. F I F
Controls the transfer of bitmap image data to O7.

The external storage device 6 is made of a hard disk, a magneto-optical disk, or the like, has an inexpensive and large-capacity storage area (several tens of megabytes to hundreds of megabytes), and is allocated as a page memory for storing full-color image data. In the case of full color with 300 dpi resolution (YMCB each 8 bits), if the paper size is A4, it will have about 32 Mbytes of page memory, and if it is a 40 Mbyte hard disk, it will have one page, and an 80 Mbyte hard disk. If so, two pages worth of image data will be stored.

On the other hand, in hard disks and magneto-optical disks, one circumference is one track, and the head is moved track by track to read/write.When accessing consecutive tracks, hard disks have a reading/writing method of 5 to 0 m5.
ec, a magneto-optical disk requires 10 to 15 m5ec. However, within the same track, the data transfer speed for both hard disks and magneto-optical disks is approximately 1
．． High speed of 2MB/sec and 300dp
This is faster than the image data transfer rate of 0.9 Mbytes/5ec (image lock frequency: 0.932 MHz) of a full-color printer engine with a throughput of one page per minute. The FIFO 7 functions as an output buffer that temporarily stores the image data to be output to the full-color printer engine, stores the image data read from the external storage device 6 in synchronization with the /FWR signal, and stores the image data read out from the external storage device 6 in synchronization with the /FWR signal. The image data stored first is read from the FIFO 7 in order by the /FRD signal synchronized with the output image clock VCLK.

A BD synchronization circuit 8 generates an image clock VCLK in synchronization with the horizontal synchronization signal /BD output from the printer engine 20. Usually, an image clock crystal oscillator (O3
C) V CL KO outputted by 11 is set to a frequency eight times that of VCLK, and is synchronized with the falling edge of /BD (FIG. 2). Reference numeral 9 denotes a margin control circuit, which determines the effective area (shaded area in FIG. 3) of image data printed in one page. Vertical direction is BD after inputting VSYNC
The top margin and the number of vertical print lines are counted by BD, and in the horizontal direction, after inputting the BD, the left margin and the number of horizontal print dots are counted by VCLK. During the shaded period in Figure 3, VDOENB is output and BD synchronization is performed. Output from the circuit; iL VCLK and NAND gate l
A read signal /FRD for FIF07 is generated at O. 12
1 is a video I/F driver/receiver circuit, which includes a circuit unit that inputs and outputs a communication line between the image forming controller 21 and the printer engine 20.

Next, a sequence of outputting bitmap image data to the printer engine for printing after the CPUI finishes generating bitmap image data for one page will be described. 4 and 5 are flowcharts showing the operation sequence of the external storage device 7 for controlling the transfer of bitmap image data from the external storage device 6 to the FIFO 7. FIG. In FIG. 4, after the CPU finishes generating one page of image data to be output to the printer engine 20 (steps al, a2), the CPU generates each color component (Y, B, C, The color component to be output first in the image data for each B) is set to color=0 and output to the external storage device control circuit 5 (step a3).

Regarding the storage control of each color component stored in the external storage device 6, the CPU uses the external storage device 6 as a virtual memory space as shown in FIG. , B in order.

Here, color=0.1.2.3 is a state variable within the external storage device control circuit 5 corresponding to each color component.

Since the printer engine 20 forms images in the order of Y-M-+C-+B, cplor=o is Y, colo
r=1 becomes a state variable that matches M, color=2 matches C, and color=3 matches B. Further, FIG. 7 is a map diagram of each color component stored in the external storage device 6 such as a hard disk. Y from the lower track to the upper track in one-to-one correspondence with the memory map diagram of FIG.
M, C, and B are stored in this order. Approximately 8 to 20 bytes of data can be stored in one track, and 8-bit width image data on A4 paper at 300 dpi can be stored in 1 track.
Since a line is approximately 2.3 bytes long, 3.3 to 8.3 lines of image data are stored in one track.

Next, in FIG. 4, the CPU 1 outputs the print signal /PRN.
When T is output to the printer engine (step a4),
Vertical synchronization request signal /V output from printer engine
It enters the SREQ wait state (step a5), and CPU1
When /VSREQ is input, the external storage device control circuit 5
The bitmap image data is instructed to be transferred to the FIFO 7. On the other hand, the external storage device control circuit 5 is
According to the transfer instruction from I, the data size Mn for one page of one package component (A4 paper 300 dpi, approximately 8 Mbytes for 8 bottles) is loaded into the page counter, and the counter value of the data transfer counter is reset (step a6
). Thereafter, a track in the external storage device 6 that matches the start address of the color value is sought (head movement) (step a7). After that, step a8. reads one byte of bitmap image data in the same track of the external storage device 6. a9), save this read data to FIFO
Output the write signal/FWR for the write operation (step a10), increment the counter value of the data transfer counter by one (step a11), store the image data in the FIFO 7 for the memory size (Nl bytes), and
IFO: Until the full status signal is output (step a12), the above (steps a8 to a1])
Repeat the sequence. The external storage device control circuit 5 is F
IFO: When full is input, the counter value of the page counter is decremented by N1 (step a1
3), the CPUI outputs a vertical synchronization signal /VSYNC (step a14). When the /VSYNC signal is output, the VCLK output from the BD synchronization circuit 8 (Figure 2)
and VDOENB output from the margin control circuit 9.
(Fig. 3) is input to the NAND gate 10 and the FIFO
It generates a read signal /FRD, reads the image data written in the FIFOT, and outputs it to the printer engine 20.

When image data is continuously read from FIFO 7 by /FRD, the image data is then transferred from external storage device 6 to FIFO 7 based on the status signal output from FIFO 7. In this case, external storage device control The operation sequence of the circuit 5 is shown in the flowchart of FIG.

FIFO7 is read by /FRD and FIFOha
When lf empty (a signal output when the data size existing in the FIFO becomes half) is output (step bl), the data transfer counter is reset (step b2), and 1 is transferred from the external storage device 6 to the FIFO 7.
Step b2) to transfer bytes, step b3) to increment the data transfer counter by one, and repeat steps b3 and b4 until N2 bytes have been transferred (step b5).

Here, N2 is determined from the data transfer rate of the same track of the external storage device, the transfer rate of image data to the printer engine, and the seek time between tracks, and the bitmap image data existing in the FIFO is half the memory size. is set to be larger than . For example, the data transfer rate for the same track is 1.2 Mbytes/sec.
, the transfer speed of image data to the printer engine is set to 0.
Assuming 9M bytes/sec, seek time between tracks of 10m5ec, and memory size of FIFO7 of 32 bytes, the image data existing in the FIFO is 4
When transferring data up to 3/3 (24 bytes), the time T required to transfer N2 bytes is: , is expressed by the following relational expression: % expression %). Perform track seek twice (n=
2), the transfer time T requires 0.03 seconds, and the number of transfer hides N2 is approximately 37 bytes.

When N2 bytes of bitmap image data are transferred from the external storage device 6 to the FIFO 7 (step b5), the counter value M of the page counter is determined (step b6).
) ; If M≧N2, the counter value is decremented by N2 (step b7); if M<N2, the counter value M is set to O, and the counter value of the data transfer counter is set to N2.
As M (step b8), the above steps bl to b6
Repeat the sequence. In addition, when M=O, that is, one page of image data for each color component is stored in the external storage device 6.
When read from c, the external storage device control circuit 5
Increment the value of olor by one step b
9) If the value of color is between 1 and 3, repeat the sequence from step a5 in Figure 4 to step blO in Figure 5 described above, and bitmap image data of color components that have not been output to the printer engine. The operation sequence of reading from the external storage device 6, writing to the FIFO 7, and outputting to the printer engine is executed.

[Other Examples]

Next, FIG. 8 is a diagram showing an image forming controller of a color printer device according to a second embodiment of the present invention, which has two external storage devices 6a and 6b as image memories. FTFO7a, which corresponds one-to-one to the device.
7b, the image data transfer speed between the external storage device and the FIFO is doubled. The external storage control circuit 5 stores the FIFO 7a,
For each line of image data read from 7b and output to the printer engine, the even-numbered image data is transferred to the FIFO 7a from the external storage device 6a, and the FIFO
In order to transfer odd-numbered image data from the external storage device 6b to the O7b, when the CPU 1 generates the image data, it separates the image data into even-numbered data and odd-numbered data and stores them in the external storage devices 6a and 6b. Also, when printing,
Based on the status signals output from FIFOs 7a and 7b, FIFO 7a is stored from external storage device 6a.
Since the image data is asynchronously transferred from the external storage device 6b to the FIFO 7b, the transfer speed is twice as high as that of the configuration of the first embodiment, and it is also compatible with a full-color printer engine that prints two pages per minute. . Note that the external storage device 6
The image data transfer sequence from a or 6b to FIFO 7a or 7b is shown in the flowchart of the first embodiment (
4 and 5).

In FIG. 8, 13 is a FIFO output circuit, which outputs V from the BD synchronization circuit 8 to FIFO 7a in which even-numbered image data is stored and FIFO 7b in which odd-numbered image data is stored. From CLK and VDOENB output from the margin control circuit 9,
As shown in the timing chart of FIG.
Signals /FRDA and /FRD to read 7a and 7b alternately
Generate B. That is, when /FRDA is true, FI
Image data is read out alternately from the FO 7a and from the FIFO 7b when /FRDB is true.

Note that in this embodiment, the configuration has two external storage devices and two FIFOs that correspond one-to-one to the external storage devices.
It is also possible to configure it with a plurality of three or more pieces, and no problem will occur. This is obviously useful in high-speed color printers where the image data transfer rate is very high.

[Third Embodiment] Note that the FIFO as a buffer provided between the external storage device and the printer engine is replaced with a memory such as SRAM, and a peripheral circuit for controlling this memory is added. FI shown in Examples and Second Example
It is also possible to perform FO-like sequences, and the invention is not limited to FIFO-only configurations.

In the embodiments of the present invention, a color printer device has been described, but it is obvious that the present invention can also be applied to a multi-value printer device that expresses gray scale or a black-and-white binary printer device.

〔Effect of the invention〕

As explained above, in the present invention, the color printer device has an inexpensive, large-capacity external storage device such as a hard disk as the image memory, and controls the transfer of image data from the external storage device to the printer engine during printing. This is done using a buffer such as a FIFO memory, an external storage control means, and an image output control means, and the cost of the image memory can be reduced by using a structure using semiconductor memory such as DRAM (
In comparison, it can be kept down to just a few tens of minutes, and constitutes an inexpensive color printer device.

[Brief explanation of drawings]

1 is a system block diagram showing the image forming controller in the color printer device of the present invention, FIG. 2 is a timing chart of the BD synchronization circuit 8, FIG. 3 is a diagram showing the timing of VDOENB in the margin control circuit 9, 4 and 5 are flowcharts for explaining the transfer of image data from the external storage device 6 to the FI'FO 7, FIG. 6 is a diagram showing a memory map in which image data of each color component is stored, and FIG. A diagram showing storage areas in an external storage device in which image data of each color component is stored. FIG. 8 is a system block diagram showing an image forming controller in a color printer device in the second embodiment. FIG. 9 is a system block diagram showing the image forming controller in the color printer device in the second embodiment. 5 is an output timing chart of image data in an example. 1... CPU 2... Bus control circuit 3... System memory 3a... Code ROM 3b... Font ROM 3c... RAM 4... Host I/F control circuit 5... External Storage device control circuit 6...External storage device 7...FIFO 8...BD synchronization circuit 9...Margin control circuit 10...NAND, IC 11...O3C (crystal oscillator) 12... Video I/F driver 6a...External storage device A 6b...External storage device 7a ---P I F OA 7b...PIFOB 13...FIFO output control circuit Renova circuit

Claims (4)

[Claims] (1) The image data generating means includes an image data generating means that generates image data of a dot image based on external print data, and a printing means that performs a printing operation based on the image data, and the image data generating means In a printer device that outputs image data to the printing means in synchronization with a synchronization signal output from the means, the image data generating means includes an auxiliary storage means capable of storing the generated image data, and a storage means for reading the generated image data from the auxiliary storage means. a buffer means for temporarily storing the image data, the image data is read from the auxiliary storage means asynchronously to the synchronization signal, and the image data is read from the buffer means to the printing means synchronously to the synchronization signal. A printer device characterized by outputting. (2) In the printer device according to claim 1, the image data generating device has a plurality of auxiliary storage means and a plurality of buffer means individually corresponding to each auxiliary storage means, and the plurality of A printer apparatus characterized in that image data is transferred from an auxiliary storage means to a plurality of buffer means in parallel, and the image data is sequentially outputted from each buffer means to the printing means based on the synchronization signal. (3) At least one page worth of bitmap image data (
A printer device that generates image data (hereinafter abbreviated as image data) and stores it in an external disk storage means, and a buffer that temporarily stores the image data between the external disk storage means and image printing means (printer engine). means, external disk storage control means for controlling the transfer of image data from the external disk storage means to the buffer means based on a status signal output from the buffer means, and a synchronization signal output from the image printing means. A printer device comprising: image output control means for controlling output of image data from the buffer means to the image printing means. (4) The printer device according to claim 3, further comprising a plurality of external disk storage means, and the buffer means in one-to-one correspondence therewith, and the image data is transferred from the external disk storage means to the buffer means. and an image output control means for controlling the output of image data from each buffer means to the image printing means based on a synchronization signal output from the image printing means. Characteristic printer device.