JP2005279973A - Print data counter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a print data counter capable of counting print data at a high rate by software without using an expensive high speed CPU. <P>SOLUTION: The print data counter counting the number of dots to be printed from raster data being outputted to a print head comprises a means storing a lookup table for converting numeric data of predetermined byte into a number of bits corresponding to the print dots, a means for reading out buffered raster data sequentially in units of predetermined byte and converting numeric data thus read out into a number of bits corresponding to the print dots based on the lookup table, and a means for adding the number of bits thus converted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a print data counting device used in an image recording apparatus that forms an output image with toner on recording paper based on output image data, such as a digital copying machine or printer.

  Conventionally, an image forming apparatus is provided with a print data count device that counts the number of print dots from image data output to a print head such as a laser head, an LED head, or an inkjet head, and an image forming material is used based on the count value. Some of them have management means for calculating the consumption amount of a certain toner or ink and managing the remaining amount of the toner or ink.

The conventional print data counting device is configured to count the number of black pixels for each pixel with a counter circuit configured by hardware for image data output to the print head. In order to reduce the cost, it has been proposed to configure a print data counting device by software.
JP 2001-270168 A JP 2002-337366 A

  However, there is a problem that the printing data counting device that uses software to reduce the component cost has a problem that the processing time becomes long and the throughput such as the printing speed decreases, and a high-speed CPU is used to increase the throughput. On the contrary, there is a problem that the cost of parts increases.

  SUMMARY OF THE INVENTION In view of the above-described conventional drawbacks, the present invention is to provide a print data counting device capable of counting print data at high speed by software without using an expensive high-speed CPU.

  In order to achieve the above object, the print data count device according to the present invention is characterized in that the number of dots printed from the raster data output to the print head is calculated as described in claim 1 of the claims. A printing data counting device for counting, storing means storing a lookup table for converting numeric data of a predetermined byte into the number of bits corresponding to a print dot, and sequentially reading buffered raster data in units of a predetermined byte In addition, there is provided a conversion processing means for converting the numerical data read based on the lookup table into the number of bits corresponding to the print dots, and an addition processing means for adding the number of converted bits.

  According to the above configuration, the number of dots to be printed from raster data, for example, the number of dots corresponding to black is counted from the numeric data of a predetermined byte by using a lookup table without counting the number of bits in 1-bit units. Since the print data can be counted simply by counting the number of bits after conversion, even when an inexpensive low-speed CPU is used, the print data can be counted very quickly. It will be possible.

  The characteristic configuration of the program for counting the number of dots to be printed from the raster data output to the print head according to the present invention is as follows. Conversion processing means for converting the read numerical data into the number of bits corresponding to the printing dots based on the lookup table for converting the numerical data of bytes into the number of bits corresponding to the printing dots, and the number of bits subjected to the conversion processing The point is to make the computer function as addition processing means for adding.

  As described above, according to the present invention, it is possible to provide a print data counting device capable of counting print data at high speed by software without using an expensive high-speed CPU.

  An embodiment of an image recording apparatus provided with a print data counting device according to the present invention will be described below. As shown in FIG. 1, a copying machine 1 as an example of an image recording apparatus includes a scanner unit 2, an image processing unit 3, an LSU 4 as a print head, an image forming unit 5, a paper feeding / conveying unit 6, a fixing unit 7, and a DF. A unit 8 and an operation unit (not shown) are provided.

  The operation unit is provided with a mode setting key for setting operation modes of various jobs of the copying machine 1, a print key for starting the set job, and the like, and a display unit for displaying setting information by the mode setting key It is comprised including the operation part (not shown) provided with.

  Image output for forming and outputting a toner image corresponding to required output image data on recording paper by the image processing unit 3, LSU 4, image forming unit 5, paper feeding and conveying unit 6, fixing unit 7 and their control units Means are configured.

  The DF unit 8 conveys a plurality of documents 80 placed on the document tray 81 one by one to a document reading position by the scanner unit 2, and discharges the document that has been read to a paper discharge tray 82.

  The scanner unit 2 converts the image information into electronic data by sending the light reflected by irradiating the document to the CCD image sensor 21 through RGB filters. The image processing unit 3 processes the signal from the CCD image sensor 21 into output image data subjected to A / D conversion, shading correction, color correction, and other image processing, and also executes toner color conversion processing described later. To do. The LSU 4 converts output image data from the image processing 3 into laser light and irradiates the photosensitive drum 51.

  The image forming unit 5 includes a photosensitive drum 51, a main charger 52, a developing unit 53, a transfer belt 54, a cleaning unit 55, a recycled toner replenishing unit 56, and a charge eliminating lamp 57. In particular, the developing unit 53 is a cyan developing unit. 531, a magenta developing unit 532, a yellow developing unit 533, a black developing unit 534, and a recycling developing unit 535. A toner cartridge filled with a corresponding color toner is detachably attached to each developing device, and the toner is supplied from the toner cartridge to the developing device.

  The main charger 52 stretches a thin tungsten wire of 50 to 100 μm in the longitudinal direction of the photosensitive drum 51 in a shield case opened toward the photosensitive drum 51, and applies a high voltage of about +5 KV to the photosensitive drum 51. The body drum 51 is positively charged. The LSU 4 irradiates the charged surface of the photosensitive drum 51 with a laser beam corresponding to the image data, whereby an electrostatic latent image is formed on the surface of the photosensitive drum 51. A toner image is formed by applying the bias voltage of the developing roller and the potential of the surface of the photosensitive drum to the toner that is agitated in the developing portion 53 and positively charged in the portion irradiated with the laser of the photosensitive drum 51, This is transferred onto the surface of the transfer belt 54. The toner that has not been transferred onto the photosensitive drum 51 is scraped off by the rubber blade 551 of the cleaning unit 55, which is the next process, and is neutralized by the neutralizing lamp 57 in order to reduce the residual potential on the surface and make it uniform. Prepares for the next series of processes.

  In the color image output mode, the above-described charging, exposure, development, cleaning, and charge removal operations are performed corresponding to each color of cyan, magenta, yellow, and black, and the respective toner images are superimposed on the transfer belt 54. The toner image is transferred to the recording paper by the secondary transfer portions 541a and 541b.

  In the case of the monotone image output mode, only the cyan developing unit 531, the magenta developing unit 532, the yellow developing unit 533, or the black developing unit 534 is used. .

  The paper feeding / conveying means 6 comprises paper feeding cassettes 611 and 612, paper feeding rollers 621 and 622, a vertical conveying path 63, a pair of registration rollers 64a and 64b, and a conveying belt 65. The paper feed cassettes 611 and 612 are provided with a paper stacking plate on which a plurality of recording papers are stacked, and this paper stacking plate is lifted up by a spring, a lift motor, etc. Is urged to come into contact with the paper feed rollers 621 and 622. The registration roller pairs 64a and 64b stop the paper at one end in order to synchronize the transfer timing of the toner image on the transfer belt 54 with respect to the conveyed paper and to adjust the leading edge of the paper, and then send the paper to the image forming unit 5. It has a role to carry. The conveyance belt 65 conveys the sheet on which the unfixed toner is transferred to the fixing unit 7. The necessary number of conveying rollers in each conveying path is laid out as needed.

  The fixing unit 7 includes a first heat roller 71, a first heater 711 inside the first heat roller 71, a second heat roller 72, a second heater 721 inside the heat roller 72, a pair of fixing discharge rollers 73a and 73b, and the like. . The heat roller pairs 71 and 72 are made of aluminum or the like having good thermal conductivity and coated with fluorine. The two heaters 711 and 721 are built in and controlled to a predetermined temperature required for fixing. The first heat roller 71 faces the second heat roller 72 and contacts with an appropriate pressure, and is driven by driving means (not shown). The heat roller pair 71, 72 is made of an aluminum roller having a good thermal conductivity, and its periphery is covered with an elastic layer in order to secure a fixing nip width. Although not shown, each roller is provided with a claw member for peeling the paper, a roller for cleaning, and a web.

  As shown in FIG. 2, the control unit 20 of the copying machine 1 includes a main CPU 21 that performs input / output conversion processing on image data read by the scanner unit 2 and image data input from a communication line (not shown). And a second control unit 20b having a system CPU 25 for controlling an image forming process operation by an image output unit.

  More specifically, the first control unit 20a constitutes the image processing unit 3. The ROM 22 stores an execution program for the main CPU 21, the RAM 23 stores image data for image processing, and the scanner unit 2. The image input / output buffer 24 for inputting the document image data read by the main CPU 21 and outputting the output image data processed by the main CPU 21 to the LSU 4 of the process processing unit is connected by the internal bus 21a. .

  The second control unit 20b includes a ROM 26 storing an execution program of the system CPU 25, a RAM 27 storing various process control data, a first input / output buffer 28, a second input / output buffer 29, and the like through an internal bus 25a. Connected and configured. The first input / output buffer 28 is an input / output port for inputting key input data from a mode setting key or the like provided in the operation unit, outputting display information or the like to the display unit, or outputting a control signal to the DF unit 8 Function as. The second input / output buffer 29 is an output to which drive signals for various elements such as a motor and a heater provided in a process processing unit for image formation such as the image forming unit 5 and the paper feeding / conveying unit 6 are output. It functions as a port and an input port to which process data from each element is input.

  The copying machine 1 is provided with toner remaining amount detecting means for detecting the remaining amount of toner filled in the toner cartridge, and the toner remaining amount detected by the toner remaining amount detecting means is a predetermined remaining amount allowable amount. When it is determined that the amount of toner is less, a pictograph indicating that the amount of remaining toner is low is displayed on the operation unit, and an arrangement for additional toner is prompted.

  As shown in FIG. 3, the toner remaining amount detecting means 200 includes a toner remaining amount storing means 201 for each toner color divided into a part of the storage area of the RAM 27, and a toner consumption amount for each output of recording paper. Toner consumption calculating means 202 for calculating, and the toner consumption calculated by the toner consumption calculating means 202 are subtracted from the toner remaining amount data stored in the toner remaining amount storing means 201 to obtain the current toner remaining amount. The toner remaining amount calculating means 207 for calculating the toner remaining amount data stored in the toner remaining amount storing means 201 is reset to the full filling amount every time the toner cartridge is replaced.

  The toner consumption calculating means 202 counts the number of dots to be printed from the raster data output to the print head. The toner consumption calculating means 202 is partitioned into a part of the storage area of the RAM 23 and corresponds to print dots from numerical data of a predetermined byte. Storage means 203 in which a look-up table to be converted into the number of bits to be stored is stored, and raster data buffered in the image input / output buffer 24 is sequentially read in units of predetermined bytes, and the numerical data read based on the look-up table is read Conversion processing means 204 for converting the number of bits corresponding to the print dots, addition processing means 205 for adding the number of converted bits, and multiplication means 206 for multiplying the addition result by the addition processing means 205 by a predetermined correlation coefficient The amount of toner consumed in the output image is estimated and calculated. Here, the correlation coefficient is obtained by experiments or the like. That is, the RAM 23 in which the lookup table is stored, the conversion processing unit 204, and the addition processing unit 205 constitute the print data counting device of the present invention.

  In the following, the operation by the toner remaining amount detecting means will be described based on the flowchart shown in FIG. When output image data corresponding to each toner of cyan (C), magenta (M), yellow (Y), and black (K) expanded into raster data is stored in the image input / output buffer 24 (S1), the main data is stored. The conversion processing means 204 composed of a part of the CPU 21 and its execution program sequentially outputs the output image data in units of 8 bits for each color of cyan (C), magenta (M), yellow (Y), and black (K). Are read out (S2), and converted into the number of print pixels with reference to the lookup table shown in FIG. 4 (S3).

  In other words, the raster data is configured so that the bits set to “1” become printing dots and the bits reset to “0” become non-printing dots. The number of print dots can be obtained by counting the number of bits set to “1” of the read numerical data.

  The above lookup table is a table set to convert 8-bit numeric data from 00H to FFH in hexadecimal notation into the number of bits corresponding to the print dot. For example, the bit set at 00H Since the number is 0, decimal is “0”, and in FFH, all bits are set, so decimal is “8”. Further, in 0FH, the number of bits set is 4, so decimal. Is associated with “4”. Therefore, if the 8-bit data read from the raster data is AEH, the table-converted data is “5” in decimal.

  The data converted into 8-bit units in this way is sequentially added by the main CPU 21 and the addition processing means 205 constituted by a part of the execution program (S4), cyan (C), magenta (M), yellow When all the print data of one page, that is, all the dot data is added corresponding to each toner of (Y) and black (K) (S5), the added value is transferred from the main CPU 21 to the system CPU 25, and the system The value is multiplied by the correlation coefficient described above by the multiplication means 206 constituted by a part of the CPU 25 and its execution program, and the amount of toner used to output the image data is derived (S6).

  The remaining toner amount derived from the remaining amount data stored in the remaining toner amount storage unit 201 is subtracted by the remaining toner amount calculating unit 207 constituted by the system CPU 25 and a part of the execution program thereof to obtain the current remaining toner amount. Is derived (S7), and the value is updated and stored in the remaining toner storage unit 201 (S8).

  That is, in the ROM 22 described above, the buffered raster data is sequentially read out in units of predetermined bytes, and the read numerical data is converted based on a lookup table that converts the numerical data of the predetermined bytes into the number of bits corresponding to the print dots. The computer functions as a conversion processing means for converting the number of bits corresponding to the print dots and an addition processing means for adding the converted bit numbers, and counts the number of dots printed from the raster data output to the print head. The program to be stored is stored.

  According to the above configuration, in order to count the number of dots printed from raster data, for example, the number of dots corresponding to black, in 1-bit units, whether or not they are set in bit units is identified and set. By using a look-up table, it is possible to quickly convert numeric data of a predetermined byte into the number of bits corresponding to the print dots without performing complicated processing such as counting up in the case of The print data can be counted simply by counting the number of bits after conversion, and the print data can be counted very quickly even when an inexpensive low-speed CPU is used. In this case, the pipeline processing of the CPU can be used effectively, and processing can be performed at higher speed.

  In the above-described embodiment, the first control unit 20a having the main CPU 21 that performs input / output conversion processing on image data read by the scanner unit 2 or image data input from a communication line (not shown), and the operation unit And a second control unit 20b having a system CPU 25 for controlling an image forming process operation by the image output means and a key input process, a display output process, and a toner remaining amount detecting means realized by the cooperative processing of both CPUs 21 and 25. However, the control unit may be configured by a single CPU and the toner remaining amount detecting means may be realized.

  In the above-described print data counting device, the conversion processing means reads and processes raster data in units of 8 bits. However, the processing unit may be 16 bits or 32 bits, and the data bus of the CPU. It is preferable to process according to the size. In this case, a lookup table that matches the processing unit may be prepared.

  In the above-described embodiment, the print data counting device used for detecting the remaining amount of toner has been described. However, the photosensitive member is adjusted so that the toner consumption is adjusted based on the count result by the print data counting device. It may be used for controlling the change of the image forming process, such as controlling the amount of charge.

  In the above-described embodiment, a copying machine capable of color output by an electrophotographic method has been described as an example of an image recording apparatus. However, the same applies to a copying machine capable of outputting only monochrome, and further to a printer, a facsimile, an inkjet printer, or the like. It goes without saying that can also be applied.

Sectional drawing explaining an image recording device Control block diagram of image recording apparatus Block diagram of the main part Illustration of lookup table Flow chart showing print data count processing

Explanation of symbols

1: Copier 2: Scanner unit 3: Image processing unit 4: LSU4
5: Image forming unit 6: Paper feeding / conveying unit 7: Fixing unit 8: DF unit 200: Toner remaining amount detecting unit 201: Toner remaining amount storing unit 202: Toner consumption calculating unit 203: Storage unit 204: Conversion processing unit 205 : Addition processing means 206: multiplication means 207: toner remaining amount calculation means

Claims (2)

A print data counting device for counting the number of dots printed from raster data output to a print head,
Storage means storing a lookup table for converting numeric data of a predetermined byte into the number of bits corresponding to a print dot, and buffered raster data are sequentially read out in units of a predetermined byte, and read based on the lookup table A print data counting device comprising: conversion processing means for converting numerical data into the number of bits corresponding to printing dots; and addition processing means for adding the converted number of bits. The buffered raster data is sequentially read in units of predetermined bytes, and the read numerical data is converted to the number of bits corresponding to the print dots based on a lookup table that converts the numerical data of the predetermined bytes into the number of bits corresponding to the print dots. A program for causing a computer to function as conversion processing means for performing conversion processing and addition processing means for adding the number of bits subjected to conversion processing, and counting the number of dots printed from raster data output to the print head.

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