JPH0939342A - Printer with test printing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct test printing by providing mode switching means for switching a normal print mode for sending image data to transfer means and a test print mode for sending test image data of test print data generating means to the transfer means 7 SOLUTION: A CPU 11 instructs the output start of a video signal to an engine controller 14, which gives the allowance of a video signal output to a line buffer 19. The buffer 19 requests the transfer of image data to a DMA controller 17, which accesses a RAM 16, reads test print image data, and transfers it to a decoding circuit 18. The circuit 18 supplies the data to the buffer 19, which generates a video signal according to test print image data, and supplies it to an engine 2. That is, a control signal is supplied to the engine 2 from an engine controller 14, a video signal is supplied from the buffer 19, and the test is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having a test printing function.

[0002]

2. Description of the Related Art Conventionally, a printer capable of printing an image of a document or the like as a dot image is a printer which is supplied from a CPU for controlling the printer according to various programs and an external device such as a personal computer (hereinafter referred to as a PC). A memory for storing data and an engine for performing a printing operation according to an image signal are provided. When the encoded print data is supplied from the PC, the CPU first stores the print data in the memory. Next, the CPU reads the print data stored in the memory, converts it into image data composed of bitmap data, and stores it again in the memory. After that, the CPU reads the image data from the memory and outputs it as an image signal to the engine to execute the printing operation. As described above, in the conventional printer, data reception and data processing are performed by software.

When performing test printing in a conventional printer, a CPU in the printer generates image data for test printing and stores it in a memory, reads the image data for test printing stored in the memory, and outputs it to the engine. . Therefore, even if the printer is connected to the PC and the print data is not supplied, the test printing can be executed by the printer alone. In such a conventional printer, the CPU needs to repeatedly access the memory for storing print data, reading print data, converting to image data, storing image data, and reading image data. Since the CPU needs to execute other processing such as engine control, the memory is accessed between the other processing, and there is a limit to increase the print processing speed.

On the other hand, a PC is recently known which is capable of creating image data composed of bitmap data, compressing the image data, and transmitting the compressed image data to a printer. If the image data is supplied from the PC, the printer does not need the relatively complicated data processing of converting the coded print data into the image data of the bitmap. Therefore, the data reception and the data processing are all performed by hardware. Can be done. A printer that performs all such data reception and data processing by hardware is a host-based printer (Host Bas
ed Printer), which has recently become popular because of its high printing speed.

The host-based printer has a CPU for controlling the printer, a memory for storing image data supplied from a PC, an engine for performing a printing operation according to an image signal, and a decoding for decompressing the compressed image data. It has a circuit and a DMA controller. The DMA controller is a circuit capable of directly writing and reading data to and from the memory by the direct memory access method without using the CPU.

Therefore, in the host-based printer, the PC
The compressed image data supplied from the CPU is directly stored in the memory by the DMA controller, and the image data stored in the memory is directly read from the memory by the DMA controller and transferred to the decoding circuit. The decoding circuit decompresses the compressed image data and outputs it to the engine. As described above, in the host-based printer, data reception and data processing such as writing, reading, and decoding are all performed by the hardware such as the DMA controller and the decoding circuit, so that the CPU stores in the memory one by one between the other processing. There is no need to access and process data, and the printing process is speeded up.

[0007]

However, in the conventional host-based printer, the CPU does not need to access the memory in the normal print processing as described above, and all the access to the memory is performed by the DMA controller. The CPU was configured so as not to directly access the memory. Therefore, the CP in the printer
It was not possible to perform test printing by generating image data for test printing by U and writing it in the memory.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a host-based printer having a test printing function.

Another object of the present invention is to provide a host-based printer capable of writing test print image data in a memory and performing test print without the CPU having to access the memory. Is.

[0010]

In order to achieve the above object, in the host-based printer according to the first aspect, the mode switching means switches between the normal print mode and the test print mode. In the normal print mode, the transfer device is supplied with image data from an external device. The transfer means directly transfers the image data to the storage means and transfers the image data stored in the storage means to the image formation means without passing through the control means for controlling the image formation means. The image forming unit is controlled by the control unit and prints according to the transferred image data.

On the other hand, in the test print mode, the image data for test print generated by the test print data generating means is supplied to the transfer means. The transfer means directly transfers the test print image data to the storage means and also transfers the test print image data stored in the storage means to the image formation means without passing through the control means for controlling the image formation means. The image forming means is controlled by the control means,
Test printing is performed according to the transferred test printing image data.

In the host-based printer according to the second aspect of the invention, the mode setting means sets one of the normal print mode and the test print mode. When the normal print mode is set, the image data supplied from the external device is received by the receiving unit and is supplied to the transfer unit via the second bus. Transfer means
The image data is transferred to the storage unit via the second bus, and the image data stored in the storage unit is transferred to the image forming unit via the second bus. The transfer unit directly transfers the image data without passing through the control unit that controls the image forming unit. The image forming unit is controlled by the control unit and prints according to the transferred image data.

On the other hand, when the test print mode is set by the mode setting means, the test print image data generated by the test print data generating means is received by the receiving means via the first bus, It is supplied to the transfer means via the second bus. The transfer means transfers the test print image data to the storage means via the second bus, and transfers the test print image data stored in the storage means to the image forming means via the second bus. The transfer unit directly transfers the test print image data without passing through the control unit that controls the image forming unit. The image forming unit is controlled by the control unit and performs test printing according to the transferred test printing image data.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the electrical configuration of a laser printer which is an embodiment of the host-based printer of the present invention. The laser printer 1 is connected to a personal computer 4 (hereinafter referred to as a PC) as a host computer, and forms an image on a medium such as plain paper according to image data and control data supplied from the PC 4. The laser printer 1 has an engine 2 including various mechanisms such as an image forming mechanism for forming an image by a laser system and a paper feeding mechanism, and a controller 3 for controlling the engine 2. The engine 2 has an operation panel 26 having keys and the like for instructing execution of test printing.
It has. For other configurations of the engine 2,
Since it is similar to the existing laser printer, its detailed description is omitted.

The PC 4 supplies image data and control data to the laser printer 1. The image data is data obtained by compressing bitmap data representing an image by a predetermined method, and the control data is data representing resolution, data representing a page break, and the like.

The controller 3 includes an interface 10 connected to the PC 4 for receiving image data and control data from the PC 4, and an 8-bit CPU 11 that receives the control data via the interface 10 and controls the entire printer. A ROM 12 storing a control program executed by the CPU 11, a RAM 13 provided with various work memories, an engine controller 14 for outputting a control signal to the engine 2 based on a command from the CPU 11, and image data. DRAM 1
6 is provided. The ROM 12 further stores programs and data necessary for the CPU 11 to generate test print image data and execute the test print processing.

The interface 10, CPU 11,
ROM12, RAM13, engine controller 14,
The DRAMs 16 are connected to each other by the CPU bus 21. The engine controller 14 and the engine 2 are
It is connected by a plurality of signal lines 23.

The controller 3 also receives the image data via the interface 10 and the decoding circuit 18 for decompressing the compressed image data, transfers the image data to the DRAM 16, and reads the image data stored in the DRAM 16. A DMA controller 17 for transferring to the decoding circuit 18 and a line buffer 19 for outputting the image data expanded by the decoding circuit 18 as a video signal to the engine 2 are provided. The line buffer 19 outputs a video signal to the engine 2 according to an instruction from the engine controller 14, and the DMA controller 17 reads out the image data stored in the DRAM 16 and transfers it to the decoding circuit 18 according to a request from the line buffer 19. In addition,
DMA controller 17 via interface 10
The image data received by the CPU includes image data supplied from the PC 4 and test print image data generated by the CPU 11.

The interface 10 and the decoding circuit 1
8, the DRAM 16, and the DMA controller 17 are connected to each other by a local bus 22. Decoding circuit 1
8 and the line buffer 19 are dedicated buses 24, the line buffer 19 and the engine 2 are signal lines 25, and the engine controller 14 and the line buffer 19 are signal lines 27.
The signal line 28 connects the DMA controller 17 and the line buffer 19.

The transfer and writing of image data to the DRAM 16 and the reading and transfer of image data from the DRAM 16 are executed by the DMA controller 17, so that the CPU 11 does not need to access the DRAM 16 for print processing. However, the CPU 11 needs to access the DRAM 16 in order to check whether there is any abnormality in the DRAM 16 when the power is turned on. Therefore, the DRAM 16 is connected to both the CPU bus 21 and the local bus 22 in order to enable access by the CPU 11 and access by the DMA controller 17. Since the CPU 11 and the DMA controller 17 cannot access the DRAM 16 at the same time due to the configuration, the DRAM 16 is connected to the CPU bus 21 and the local bus 22 via the arbitration circuit 15. The arbitration circuit 15 allows access to the DRAM 16 by either the CPU 11 or the DMA controller 17. The DRAM of the controller 3 described above
Elements other than 16 are ASIC (Application Specified
It is a single chip as an integrated circuit (application-specific IC).

The interface 10 switches between the normal print mode for supplying the image data supplied from the PC 4 to the DMA controller 17 and the test print mode for supplying the test print image data generated by the CPU 11 to the DMA controller 17. . Hereinafter, the circuit configuration of the portion related to the mode switching function of the interface 10 will be described with reference to FIG.

The interface 10 is provided with a latch 30 connected to the CPU 11, a selector 31 connected to the CPU 11, the PC 4 and the latch 30, and a latch 32 connected to the selector 31 and the DMA controller 17. The latch 30 temporarily stores the test printing image data generated by the CPU 11 byte by byte according to the write signal CWR supplied from the CPU 11. The selector 31 sets one of the normal print mode and the test print mode according to the mode selection signal SEL supplied from the CPU 11. For example, when the mode selection signal SEL is low level, the normal print mode is set, and when the mode selection signal SEL is high level, the test print mode is set. The latch 32, according to the write signal WR supplied from the selector 31,
The image data or the image data for test printing is temporarily stored byte by byte and supplied to the DMA controller 17.

When the strobe signal ST is supplied from the PC 4 when the normal print mode is set by the selector 31, the selector 31 receives the image data transmitted by the PC 4 byte by byte and, together with the write signal WR. , And supplies the received image data to the latch 32. On the other hand, when the strobe signal CST is supplied from the CPU 11 when the test print mode is set by the selector 31, the selector 31 latches the test print image data stored in the latch 30 together with the write signal WR to the latch 32. Supply to.

Next, the operation of the laser printer 1 will be described. When the power of the laser printer 1 is turned on,
The CPU 11 requests the arbitration circuit 15 to access the DRAM 16 via the CPU bus 21, and when the arbitration circuit 15 permits the access, the DRAM 16 is checked. The CPU 11 also uses the mode selection signal SEL
Is set to the low level to set the selector 31 to the normal print mode.

In the normal print mode, when image data is transmitted from the PC 4 following the strobe signal ST, the image data is supplied to the DMA controller 17 via the selector 31 and the latch 32 of the interface 10. The DMA controller 17 transfers the image data to the DRAM 16 via the local bus 22.

After transmitting the image data for one page, the PC 4 transmits the control data indicating the page break. The control data representing the page break is the interface 10 and C.
It is supplied to the CPU 11 via the PU bus 21. CPU
Reference numeral 11 causes the engine 2 to start an image forming operation in accordance with control data representing a page break. That is, CPU1
Reference numeral 1 instructs the engine controller 14 to drive the image forming mechanism, the paper feeding mechanism, and the like. Engine controller 14
Outputs a control signal to the engine 2 according to a command from the CPU 11 to start driving the engine 2.

On the other hand, the CPU 11 commands the engine controller 14 to start outputting a video signal. The engine controller 14 gives the permission of the video signal output to the line buffer 19 via the signal line 27. The line buffer 19 requests the DMA controller 17 to transfer image data via the signal line 28. DMA controller 17
Accesses the DRAM 16 via the local bus 22 and starts reading the image data stored in the DRAM 16. The DMA controller 17 reads the image data from the DRAM 16 line by line and transfers it to the decoding circuit 18 via the local bus 22. Decoding circuit 1
Reference numeral 8 decompresses the compressed image data and supplies it to the line buffer 19 via the dedicated bus 24. The line buffer 19 generates a video signal according to the supplied image data and supplies it to the engine 2 via the signal line 25.

In this way, the engine 2 receives the control signal from the engine controller 14 and the line buffer 1
A video signal is supplied from 9 and the engine 2 performs a laser-type image forming operation. The control of the engine 2 by the CPU 11 is executed via the CPU bus 21,
DRAM 1 for image data by DMA controller 17
Since writing and reading to and from 6 are performed via the local bus 22, when the image data for a plurality of pages is supplied from the PC 4, the image data receiving process and the image forming process can be performed at the same time, and printing is performed. The processing time can be shortened.

On the other hand, by operating the keys on the operation panel 26,
When the execution of the test print is instructed, the CPU 11 causes the RO
The image data for test printing is created according to the program and data for test printing stored in M12, and the CPU
It is supplied to the interface 10 via the bus 21. Specifically, the CPU 11 firstly, the mode selection signal SEL
Is set to a high level to set the selector 31 to the test print mode. In the test print mode, the CPU 11
Supplies the test print image data byte by byte to the latch 30 together with the write signal CWR. And CP
When U11 supplies the strobe signal to the selector 31,
Image data for test printing is sent from the latch 30 to the selector 3
1, and is supplied to the DMA controller 17 via the latch 32. The DMA controller 17 uses the local bus 22.
The test print image data is transferred to the DRAM 16 via the.

When all the test print image data is stored in the DRAM 16, the CPU 11 instructs the engine controller 14 to drive the image forming mechanism, the paper feeding mechanism, etc. in order to start the image forming operation by the engine 2. The engine controller 14 outputs a control signal to the engine 2 according to a command from the CPU 11 to start driving the engine 2.

On the other hand, the CPU 11 commands the engine controller 14 to start outputting a video signal. The engine controller 14 gives the permission of the video signal output to the line buffer 19 via the signal line 27. The line buffer 19 requests the DMA controller 17 to transfer image data via the signal line 28. DMA controller 17
Accesses the DRAM 16 via the local bus 22 and starts reading the test print image data stored in the DRAM 16. DMA controller 17
The test printing image data is read from the RAM 16 line by line, and the decoding circuit 18 reads the data via the local bus 22.
Transfer to. The decoding circuit 18 expands the compressed test print image data and supplies it to the line buffer 19 via the dedicated bus 24. The line buffer 19 is
A video signal is generated according to the supplied image data for test printing and is supplied to the engine 2 via the signal line 25.

In this way, the engine 2 receives the control signal from the engine controller 14 and the line buffer 1
The video signal is supplied from 9 and the engine 2 executes the image forming operation based on the test print image data, that is, the test print.

In the above embodiment, the engine 2 serves as the image forming means, the CPU 11 serves as the control means, and the DRA serves as the DRA.
M16 is a storage means, DMA controller 17 is a transfer means, CPU11 and ROM12 are a test print data generation means, PC4 is an external device, operation panel 26, CP.
U11 and the selector 31 correspond to the mode switching means.
Further, the interface 10 corresponds to the receiving means, the CPU bus 21 corresponds to the first bus, the local bus 22 corresponds to the second bus, and the operation panel 26, the CPU 11, and the selector 31 correspond to the mode setting means.

[0035]

As is apparent from the above description,
The host-based printer according to claim 1 comprises a test print data generating means and a mode switching means,
When the mode switching unit switches to the test printing mode, the test printing image data generated by the test printing data generating unit is supplied to the transfer unit and transferred to the storage unit without the control unit. At the same time, it is transferred to the image forming means. Therefore, in the host-based printer, the test printing can be executed without the control means accessing the storage means.

The host-based printer according to a second aspect of the invention is provided with the test print data generating means and the mode setting means, and when the test print mode is set by the mode setting means, the test print data generating means operates. The generated test print image data is supplied to the transfer means via the receiving means, and is transferred to the storage means and the image forming means by the transfer means without passing through the control means. Therefore, in the host-based printer, the test printing can be executed without the control means accessing the storage means.

Further, in the host-based printer according to the second aspect, the first bus connects the receiving means, the control means and the test print data generating means, and the second bus connects the receiving means, the storing means and the transferring means. And are connected.
The image data supplied from the external device or the test print image data generated by the test print data generating means is transferred by the transfer means via the second bus. Therefore, the first bus to which the control means is connected is not occupied by the transfer means during the transfer of the image data or the test print image data by the transfer means. Therefore,
Since the transfer of the image data or the test print image data by the transfer unit and the control of the image forming unit by the control unit can be simultaneously executed in parallel, the print processing speed can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a laser printer according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a portion related to a mode switching function of the interface of the laser printer.

[Explanation of symbols]

 1 Laser Printer 2 Engine 3 Controller 4 Personal Computer 10 Interface 11 CPU 12 ROM 16 DRAM 17 DMA Controller 21 CPU Bus 22 Local Bus 26 Operation Panel 31 Selector

Claims (2)

[Claims] 1. A host-based printer for receiving data and processing data by hardware for printing, and image forming means for forming an image in accordance with image data, and control means for controlling the image forming means. A storage unit for storing image data; a transfer of the image data to the storage unit; and a transfer of the image data stored in the storage unit to the image forming unit, without passing through the control unit. Transfer means for direct execution, test print data generation means for generating test print image data, normal print mode for supplying image data supplied from an external device to the transfer means, and test print data generation Mode switching means for switching between the test print mode for supplying the test image data generated by the means to the transfer means. A host-based printer, characterized in that it has a step. 2. A host-based printer that receives data and processes data by hardware to print, and image forming means for forming an image according to image data, and control means for controlling the image forming means. A test print data generating means for generating test print image data, an image data supplied from an external device, and a receiving means for receiving the test print image data generated by the test print data generating means A first bus for connecting the receiving means, the control means, and the test print data generating means, a storage means for storing image data, the storage of the image data received by the receiving means Transfer to the image forming means and transfer of the image data stored in the storage means to the image forming means via the control means. Transfer means for directly performing the operation, a second bus for connecting the receiving means, the storage means, and the transferring means, and image data received by the receiving means from the external device to the transferring means. A mode for setting one of a normal print mode for supplying and a test print mode for supplying the test print image data received by the receiving means from the test print data generating means to the transfer means. A host-based printer, comprising: a setting unit.