JP2007283735A - Printer controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device which carries out own energy-saving and maintains precision for an equal interval between lines. <P>SOLUTION: The printer controller makes control through BD (main-scanning synchronizing signal) which is not thinned out from the engine even at a 1/2 speed and a 1/4 speed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printer control apparatus provided with a multi-beam optical system.

  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, in recent color printers, in order to reduce the cost of the apparatus, the main body of the printer does not have an expansion function, and the host performs image processing and image compression, and the printer receives the compressed image data and receives the internal memory. An image printing apparatus in which the image data stored in the image data is stored and transferred to a recording unit (engine unit) while being expanded by a decompression circuit of each (YMCK) when printing is started has been widely used.

  Also, in order to increase the speed and recording density of the device, a multi-beam optical system that writes simultaneously with two or more laser beams instead of scanning with only one laser beam is put into practical use. Has been.

  In such a model, when printing on special paper such as thick paper or OHP paper on the paper to be transferred, 1 / 2Speed mode or 1 / 4Speed with reduced transport speed to achieve sufficient fixability A mode is available.

  FIG. 3 shows a relationship between a BD (main scanning synchronization signal) output from the engine and a video signal (VDO) output in synchronization with the BD.

  In the normal mode (1/1 Speed mode), video signals (VDO11, VDO12) are output from the two laser beams to the engine in synchronization with the falling edge of the BD.

  In 1/2 Speed mode, the paper transport speed on the engine side becomes 1/2 Speed, and at the same time the BD in the broken line is thinned out from the engine side and output, so the video signal output from the controller is also thinned out. It will be output at the same timing.

  Similarly, in the 1/4 Speed mode, the paper transport speed becomes 1/4 Speed, and at the same time, the BD in the broken line part is output to the controller side at the timing when it is thinned, realizing 1/4 Speed printing.

Patent Document 1 describes an example in which a plurality of laser beams are used and the number of beams to be used is switched depending on a mode.
Japanese Patent Application Laid-Open No. 2002-166592

  However, in the above conventional example, it is necessary to always drive two laser beams even in the 1/2 Speed mode or 1/4 Speed mode, as in the normal mode (1/1 Speed mode).

  Therefore, on the controller side, the two video signal transfer circuits used to drive the two beams are always used in an operable state, and even in 1/2 Speed mode or 1/4 Speed mode. The same power as that in the normal mode is consumed.

  In addition, when a video signal is output in synchronization with the BD thinned out on the engine side, there may be a case where the equal interval accuracy between the lines cannot be maintained, such as the 1/2 Speed mode and the 1/4 Speed mode.

  In this embodiment, 1 / 2Speed or 1 / 4Speed used when printing on special paper such as thick paper or OHP paper in a printer that writes a latent image using two or more laser beams. Video signal output control at the time of receiving a BD signal (main scanning synchronization signal) without decimation from the engine side, a video signal output to the engine side from the received BD signal (main scanning synchronization signal) without decimation The controller has a means to judge the timing of the video signal. When the 1 / 2Speed mode or 1 / 4Speed mode is set, the timing of the video signal to be output is synchronized with the input BD signal (main scanning synchronization signal). By judging which BD the output is to be made and stopping the supply of CLK to unnecessary control blocks, the device itself can save energy and line It is possible to maintain the equidistant accuracy.

  As described above, 1 / 2Speed and 1 / 4Speed used when printing on special paper such as thick paper and OHP paper in a printer that writes latent images using two or more laser beams. Video signal output control at the time of receiving a BD signal (main scanning synchronization signal) without decimation from the engine side, a video signal output to the engine side from the received BD signal (main scanning synchronization signal) without decimation Is determined by the controller side to control which beam of the multi-beam is switched and lit at which BD timing, and by restricting the supply of CLK to unnecessary blocks, In addition to saving energy, it is possible to maintain equal spacing accuracy between lines.

Example 1
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 character patterns from a data source (not shown).

  In FIG. 2, reference numeral 2 denotes a printer body which inputs and stores print information (character code, etc.), form pattern information, compressed image data, etc. supplied from an externally connected host computer. Then, according to the information, a corresponding character pattern, form pattern, or the like is created, or an image is formed on a recording paper as a storage medium while developing compressed image data.

  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 having a corresponding character pattern or transfers the compressed image data to the laser scanner unit 209 while expanding the compressed image data.

  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 115 denotes an interface unit (I / F unit), which is an external device (host computer, image scanner, etc.). ) Input code data and compressed image data.

  Reference numeral 102 denotes a CPU which executes a control program stored in the ROM unit 104 and 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 various programs (firmware) to be executed by the CPU 102.

  Reference numeral 101 denotes an ASIC that includes a HOST I / F control unit 115, a CPU I / F control unit 116, a memory control unit 105, decompression circuits 106, 107, 108, 109, an engine I / F control unit 110, 111, 112, 113, and the like. Contains.

  The HOST I / F control unit 115 exchanges control signals with the host computer and transmits data through the interface cable.

  For data reception, the received data is stored in the RAM unit 103 by DMA control in conjunction with the memory control unit 105.

  The CPU I / F control unit 116 literally controls the interface with the CPU 102, and controls access to control registers and data registers (not shown) in the ASIC.

  The memory control unit 105 is a block that controls access to the ROM unit 104 and the RAM unit 103 and controls DMA transfer and arbitration of data between the blocks.

  The decompression circuits 106, 107, 108, and 109 output the compressed image data stored in the RAM unit 103 from the RAM unit 103 according to the arbitration of the memory control unit 105 according to the request signal output from each decompression circuit. Means for receiving compressed image data.

  In the decompression circuit, there are decompression circuits for yellow (Y), magenta (M), cyan (C), and black (K), respectively, decompressing the compressed image data transferred from the RAM unit 103, and the engine I / F units 110, 111, 112, and 113 are used for output.

  Further, the CPU 102 always exchanges commands and statuses with the recording unit at regular intervals, grasps the state of the recording unit, sends a print command, etc., and exchanges with the recording unit.

  The engine I / F units 110, 111, 112, and 113 generate a sub-scan enable signal and a main scan enable signal based on the input synchronization signals (sub-scan synchronization signal and main scan synchronization signal), and the generated enable signal In response to the signal, the image data is requested to the decompression circuit, and the image data input from the decompression circuit is converted into video data corresponding to the output gradation (one pixel is 1 bit, 2 Converted into bits, 4 bits, etc.) and transferred to the recording unit together with the transfer CLK.

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

  This embodiment has a 2-channel 4-channel (YMCK) video signal output means.

  First, when the host computer starts printing, an image is formed on the host computer, the formed image is compressed, and the compressed image is input to the printer via various interfaces.

  On the printer side, various parameters (printing range etc.) necessary for printing an image are set in S601.

  In step S602, it is determined whether the output mode is plain paper or special paper. If the output mode is plain paper, the process proceeds to step S606 and normal printing is performed.

  If it is determined that the paper is special paper, the process proceeds to S603 and the 1-beam mode is set.

  FIG. 5 is a detailed block diagram of the engine I / F circuit (110 to 113).

  In the engine I / F circuit, when a BD signal (main scanning synchronization signal) is input from the engine unit, the control circuits 501 and 504 are expanded according to the values set in advance by the CPU 102 (expanded circuits corresponding to each). 106-109), a request signal (decompressed image data request) is output.

  Upon receiving the request, the decompression circuit transfers the decompressed image data to the corresponding engine I / F circuit.

  The transferred image data is stored in the buffer circuit 502 of the engine I / F circuit, subjected to parallel / serial conversion, and input to the PWM circuit 503.

  The image data input to the PWM circuit 503 is converted by the PWM circuit and output to the engine unit as a video signal.

  The VCLK generation circuit 507 is a circuit for controlling VCLK supplied to each block of the engine I / F circuit. VCLK1 is supplied to the control circuit 501, the buffer circuit 502 and the PWM circuit 503, and VCLK2 is supplied to the control circuit 504. , Are supplied to the buffer circuit 505 and the PWM circuit 506, and can be arbitrarily set ON / OFF from the CPU 102.

  FIG. 4 is a timing chart showing the timings of 1 / 2-speed and 1 / 4-speed BD signals and video signals in this embodiment.

  VDO11 and VDO12 represent two video signals with two beam outputs, and the same operation is performed when there are four channels of Y, M, C, and K.

  When the one beam mode is entered in S603, the VCLK generation circuit 507 causes the VCLK1 to be in the output mode and the VCLK2 to be in the stop mode.

  In S604, the 1 / 2Speed mode or 1 / 4Speed mode is selected. If the 1 / 4Speed mode is selected, the control circuit 501 performs video signal output control according to 1 / 4Speed in S605. Is set.

  4 represents the video signal output timing in the 1-beam mode. The VDO 12 is in a stopped state with respect to the BD signal output from the engine side, and the VDO 11 stores image data corresponding to all BDs. By outputting, 1 / 2Speed is supported.

  In the case of 1/4 Speed in FIG. 4, 1/4 Speed is realized by outputting the output timing of the video signal of the VDO 11 with an interval of 1BD.

  In step S606, printing is started at a position where each set value necessary for printing is set.

  In S607, it is determined whether or not the print is continuous. If the print is continuous, the process returns to S602, and if it is the final page, the process ends.

(Example 2)
In the above embodiment, the VDO 12 is stopped and the VDO 11 is used as the video signal output out of the two beam outputs as shown in FIG. 4, but the VDO 11 is stopped and the VDO 12 is used as the video signal output. It is also possible to adopt a configuration in which the beam to be used is switched in a timely manner.

  By adopting such a configuration, it is possible to avoid a load being applied to only one of the two beams, and to improve the lifetime of the beam and the reliability against failure.

Block diagram of printer control device Block diagram of the printer Conventional timing Timing of this example Block diagram of this embodiment Flow chart of this embodiment

Explanation of symbols

101 ASIC section 102 CPU
103 RAM section 104 ROM section 105 Memory control section 106 Decompression circuit Y
107 Decompression circuit M
108 Expansion circuit C
109 Expansion circuit K
110 Engine I / F circuit Y
111 Engine I / F circuit M
112 Engine I / F circuit C
113 Engine I / F circuit K
114 Engine part (recording part)
115 HOST I / F section 116 CPU I / F section 117 HOST

Claims (6)

  Means for receiving code data and compressed image data from an external device; means for decompressing the compressed image data; and using the plurality of laser beams of two or more while decompressing the compressed image data A printer control apparatus characterized in that, in an apparatus having means for transferring to a recording unit, image data to be transferred is output in accordance with the conveyance speed of the recording unit.   2. The printer control apparatus according to claim 1, wherein the image data to be transferred is output in synchronization with a main scanning synchronization signal output from a recording unit.   3. The printer control apparatus according to claim 2, wherein the main scanning synchronization signal output from the recording unit is always output at a constant interval even if the conveyance speed is changed.   3. The printer control according to claim 2, further comprising a determination unit that determines at which main scanning synchronization timing of the main scanning synchronization signal output from the recording unit the image data is transferred to the recording unit. apparatus.   5. The printer control apparatus according to claim 4, wherein the supply of CLK to the unnecessary image data output circuit is stopped based on the determination result of the determination means.   6. The printer control apparatus according to claim 5, wherein a circuit for stopping the CLK is controlled to be switched according to the state of the load.

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