JP2006346883A - Printer apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the function of accessing a memory from a CPU and to enhance the performance of an apparatus itself by reducing the number of accesses to the memory taken place when image data is transferred to the printing apparatus in a printer controller which has a means for setting right and left mask regions (regions forbidden from video data transfer) to the image data transferred from a host or the image data bit map developed on a printer when the image data is transferred to the printing apparatus. <P>SOLUTION: Reading accessing to the memory is omitted (Writing accessing is carried out only when memory clearing is necessary.) at the region where an output range is masked by a mask signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device in a printer apparatus.

  Conventionally, in an electrophotographic printer typified by a laser beam printer, print data (code data, image data, etc.) is received from an external device such as a host computer, and bits based on the received print data. The map data is expanded, and after the expansion is completed, the expanded bitmap data is output to the printer engine as video data.

  By the way, the resolution of these types of devices has become very high, and along with this, the memory capacity for developing bitmaps has become enormous.

  A well-known technique for solving this is a method of dividing one page into a plurality of bands, including a plurality of bands of memory, and developing bitmaps in units of bands, instead of having one page of memory. It is.

  In other words, in such an apparatus, the first band video data is transmitted to the printer engine unit, and when the data is transmitted, the CPU expands the second band to be transmitted next. Is repeated to print one page.

  In order to cope with high resolution, the printing section has two laser drivers for converting a video signal into laser light, and has means for simultaneously forming a character pattern on two lines on the electrostatic drum. Printers have also appeared.

As another conventional example, Patent Literature 1 and Patent Literature 2 can be cited.
JP 2003-039743 A JP 2004-066651 A

  However, in the above conventional example, while transmitting video data to the printer engine unit, development of the next band and communication with the host computer (reception of data of the next page, etc.) must be performed simultaneously. Memory is accessed frequently.

  During normal printing operation, memory access for transmitting video data to the printer engine unit is performed with the highest priority. Therefore, even if the CPU accesses the memory, it waits until the video data access is completed.

  Especially in high-resolution and high-speed printers as in recent years, it takes a lot of memory access time to transfer video data, so the performance of the device does not stop, and the development of the next band is not in time. , Printing was done at the resolution.

  If the development of the next band is not in time before the development of one band, the resolution was printed.

  In particular, in a tandem color printer, video data for four colors are simultaneously transferred to the engine, so memory access is frequently performed for video transfer, which hinders CPU memory access and causes performance degradation. .

  According to the present invention, when the image data transferred from the host as shown in FIG. 3 or the bitmap-developed image data on the printer is transferred to the printing apparatus, the left and right mask areas ( In a printer control apparatus having means for setting a video data transfer prohibition area), read access to the memory is omitted in areas where the output range is masked by a mask signal (when write access requires memory clear) By doing this only, the number of accesses to the memory that occur to transfer the image data to the printing apparatus is reduced, and the memory access from the CPU is improved, so that the performance of the apparatus situation can be improved.

  As described above, the left and right mask areas (video data transfer prohibition areas) when transferring the image data to the printing apparatus for the image data transferred from the host or the bitmap-developed image data on the printer. In the printer control device having a means for setting the memory, in the area where the output range is masked by the mask signal, read access to the memory is omitted (write access is performed only when memory clear is necessary) By reducing the number of accesses to the memory that are generated for transferring the image data to the printing apparatus and improving the memory access from the CPU, the performance of the apparatus can be improved.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 2 is a diagram showing a printing system to which the printer of the present invention is applied.

  In the drawing, reference numeral 2 denotes a printer which inputs data from various external devices such as a host computer and executes recording on a recording medium.

  In this embodiment, the printer 2 is a laser beam printer. The configuration of the laser beam printer to which this embodiment is applied will be described below with reference to FIG.

  FIG. 2 is a cross-sectional view showing the internal structure of the printer 2 of this embodiment. This printer can register a character pattern from a data source (not shown).

  In FIG. 2, reference numeral 2 denotes a printer main body, which inputs and stores printing information (character code, etc.), form pattern information, or macro commands supplied from an externally connected host computer. A corresponding character pattern, form pattern, or the like is created according to the information, and an image is formed on a recording sheet as a storage medium.

  Reference numeral 200 denotes an operation panel on which switches and LED indicators for various operations are arranged, and 201 denotes a printer control unit that executes overall control in the printer 2 and analyzes character information supplied from a host computer or the like. (Controller).

  The printer control unit 201 mainly converts character information into a video signal of a corresponding character pattern and sends it to the laser scanner unit 209.

  When printing is started, the printer 2 starts a paper feeding operation for feeding recording paper into the apparatus from the paper feeding cassette 202 or the manual feed tray 203.

  The recording paper thus fed is sent to the paper feed unit 204 and conveyed so as to sequentially pass through the developing units 205, 206, 207 and 208.

  At the same time, the image data for each color developed by the controller 201 is sent to the laser scanner unit 209 after image conversion processing.

  The laser scanner unit 209 is a circuit for driving a semiconductor laser, and switches ON / OFF of laser light emitted from the semiconductor laser in accordance with input image data.

  For the image data sent to the laser scanner unit 209, the photosensitive drums of the phenomenon units 205, 206, 207, and 208 are laser-scanned based on the image data for each color, and a desired color is formed on the photosensitive drum corresponding to each color. An image is formed.

  By synchronizing the formation of the image data for each color with the conveyance of the recording paper, the color image of each color is developed on the recording paper conveyed by the conveyance unit 204.

  Further, sensors for detecting the remaining amount of toner are attached to the developing units 205, 206, 207, and 208, and information from the sensors is sent to the control system of the recording unit in accordance with the decrease in toner.

  The recording paper on which the color image is printed in this manner is thermally fixed by the fixing unit 210 and is abolished in the paper feed tray 211.

  With such a configuration of the printer 2, since development can be performed independently for each color, a printed image can be obtained at a very high speed.

  FIG. 1 is a block diagram showing a detailed configuration of the printer control unit 201 in the printer 2 described above. In FIG. 1, reference numeral 101 denotes an interface unit (I / F unit), which is an external device (host computer, image scanner, etc.). ) Input code data and image data.

  A CPU 102 controls the entire printer.

  Reference numeral 103 denotes a RAM unit which provides an area for storing recording data sent from the host computer for printing and a work area necessary for the CPU 102 to execute various controls as a work memory.

  A ROM unit 104 stores an area for storing various programs (firmware) to be executed by the CPU 102 and various font data for image development of code data.

  Reference numeral 105 denotes a block for controlling data DMA transfer and arbitration between blocks.

  The DMA circuits 106, 107, 108, and 109 receive the image data developed from the RAM unit 103 from the RAM unit 103 according to the arbitration of the control unit 105 in accordance with the address output from each DMA circuit. Have means.

  In the DMA circuit, there is one DMA circuit for each of yellow (Y), magenta (M), cyan (C), and black (K), and the image data transferred from the RAM unit 103 is transferred to the I / F. The output is via the part.

  In addition, the I / F unit constantly exchanges commands and statuses with the recording unit at regular intervals, grasps the state of the recording unit, sends a print command, and controls the operation of the recording unit. .

  FIG. 4 shows the internal configuration of the DMA circuit. A synchronization signal from the recording unit is input to the DMA circuit via the I / F unit.

  A sub-scan enable signal and a main-scan enable signal are generated by the sub-scan enable generation circuit 401 and the main-scan enable generation circuit 402 based on the input synchronization signal (sub-scan synchronization signal, main scan synchronization signal).

  The generated enable signal is input to the address generation circuit 404, generates an address and a request signal, and outputs it to the control unit 10 5.

  The control unit 105 reads image data from the RAM unit 103 based on the given address, and outputs the read data to the DMA circuit.

  In the DMA circuit, processing such as converting the image data input from the control unit 105 into video data corresponding to the output gradation or masking the output video data is performed.

  The mask signal generation circuit 403 is a circuit that generates a mask signal to be applied to output video data, and the CPU 102 sets a mask range in the mask circuit generation device 403 through a data bus.

  Next, the operation of this embodiment will be described with reference to the flowchart of FIG. 5 and the block diagram of FIG.

  First, when code data and bitmap data are input from an external device (such as a host computer) from S501 and S502, the data sent from the external device is expanded on the memory, and at the same time, each video data output range ( The top margin, the left margin, the sub-scan output range, the main scan output range, etc. are set.

  When the setting of each register and the development of the bitmap are completed, the controller issues a print command to the engine and waits for a sub-scanning synchronization signal from the engine.

  When a sub-scan synchronization signal is detected in S503, a sub-scan enable signal is output from the preset sub-scan enable generation circuit 401 to the address generation circuit 404.

  Similarly, from S504, a main scanning enable signal is generated from the main scanning enable generation circuit 402 based on a preset value.

  Here, the request signal and address generated from the address generation circuit 404 are configured to retrieve the image data of the next line when the previous line is completed, and are read from the memory at the start of the line. Image data is stored in the video data generation circuit 405 and is on standby.

  In S505, the address generation circuit 404 compares the main scan enable signal and the mask signal. If the range of the main scan enable signal and the mask signal is the same, the entire area is read from the memory in S506. And write (0 clear).

  If the image range to be output by the mask signal is narrowed as a result of the comparison between the main scanning enable signal and the mask signal, the memory area is written to the memory in the area where the output range is masked from S507. Only (0 clear) is performed, and only reading and writing (0 clear) to the memory are performed in the range where image data is output.

  If the above operation is performed for each line and band control is performed, the process ends when the final band is output.

  In the first embodiment, the control for clearing the read area to 0 when the image data is read from the memory has been described. However, the same image is continuously printed or the image data on the memory is erased ( If not cleared, the procedure is as shown in the flowchart of FIG.

  The procedure up to S604 is the same as that shown in FIG. 5. In S605, the address generation circuit 404 compares the main scan enable signal with the mask signal. If the range of the main scan enable signal and the mask signal is the same, S606 is executed. As a result, only the read operation is performed on the read region of the memory.

  If the image range to be output by the mask signal is narrowed as a result of the comparison between the main scanning enable signal and the mask signal, the memory area is masked in the area where the output range is masked from S607. Thus, only the range in which image data is output is read from the memory without access.

  By performing the procedure as described above, it is possible to obtain the same effect as in the above embodiment.

Block diagram of printer control device Block diagram of the printer Video data output range DMA circuit block diagram Flow chart of this embodiment Flowchart of another embodiment

Explanation of symbols

101 I / F unit 102 CPU
103 RAM section 104 ROM section 105 Control section 106 DMA circuit M
107 DMA circuit C
108 DMA circuit Y
109 DMA circuit K
110 I / F part M
111 I / F part C
112 I / F part Y
113 I / F part K

Claims (2)

  Means for receiving code data and bitmap data from an external device; means for expanding the code data on a memory in a band unit; means for transferring the bitmap data expanded on the memory to a printing device as video data; An apparatus having means capable of setting left and right video data transfer prohibition areas for the video data to be transferred, wherein read access from a memory is restricted in the video data transfer prohibition area.   2. The printer apparatus according to claim 1, wherein in the video data transfer prohibited area, only memory clear (write of 0 data) is performed without performing read access.

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