JP5857490B2 - Image forming apparatus, toner consumption calculation method, and toner consumption calculation program - Google Patents

Description

  The present invention relates to an image forming apparatus, a toner consumption calculation method, and a toner consumption calculation program.

  Conventionally, for example, in an electrophotographic image forming apparatus, a toner amount in a developing device is kept constant by supplying toner from a toner container into the developing device. In order to keep the toner amount in the developing device constant, it is necessary to replenish the toner by accurately detecting the toner consumption amount in the developing device.

  As a method for detecting the toner consumption amount in the developing device, there is known a two-dimensional toner consumption counting method for calculating the toner consumption amount in consideration of the continuity of print dots in the main scanning direction and the sub-scanning direction with respect to the target pixel. It has been. However, in consideration of the continuity of such printing dots, the toner consumption amount can be detected only after the electrostatic latent image for one page is formed. Therefore, in the case of high printing rate or long printing, the amount of toner in the developing device may rapidly decrease and insufficient toner supply may occur when an electrostatic latent image for one page is formed. there were.

  A method is known in which the toner consumption amount is predicted from the count value by counting the image information signal for each divided image area without waiting for completion of the electrostatic latent image for one page described above (for example, , See Patent Document 1).

  However, in the method shown in Patent Document 1, since the image area is simply divided and the image information signal is counted for each divided image area, the count value includes, for example, the boundary dots in the divided image area. The dot continuity of the surrounding area with respect to is not considered. For this reason, the technique disclosed in Patent Document 1 has a problem that the toner consumption amount can be detected at an early stage for each divided image region, while the toner consumption amount for each divided image region cannot be detected accurately.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus, a toner consumption calculation method, and a toner consumption calculation program that detect toner consumption accurately and early. And

In order to achieve the above object, the present invention is an image forming apparatus that calculates toner consumption based on a print dot array corresponding to input print data, and counts the number of input lines in the print dot array. Image line detection means, dot array division means for dividing the print dot arrangement based on the number of lines obtained by the image line detection means and preset division lines, and printing divided by the dot arrangement division means A toner consumption amount calculating means for calculating a toner consumption amount using a dot array, and a toner consumption correction amount calculating means for calculating a toner consumption correction amount using a print dot array corresponding to a boundary region of the divided print dot array. possess the door, the toner consumption correction amount calculating means, the toner consumption amount of correction in the first region of the divided printed dot array And characterized by calculating the toner consumption amount of correction in the second region, and further calculates the toner consumption amount of correction in the third region, each of the boundary regions overlap the first region and the second region To do.

The present invention also provides a toner consumption calculation method in an image forming apparatus that calculates toner consumption based on a print dot array corresponding to input print data, and calculates the calculated toner consumption. An image line detection procedure for counting the number of input lines of the print dot array; a dot array division procedure for dividing the print dot array based on the number of lines obtained by the image line detection procedure and a preset division line; A toner consumption calculation procedure for calculating a toner consumption amount using the print dot array divided by the dot array division procedure, and a toner consumption correction using a print dot array corresponding to a boundary region of the divided print dot array have a toner consumption correction amount calculation procedure for calculating the amount of the toner consumption correction amount calculation procedure, the divided printed dots A toner consumption correction amount in the first region of the row and a toner consumption correction amount in the second region are calculated, and a third region where the boundary regions of the first region and the second region overlap each other The toner consumption correction amount at is calculated.

  Further, the present invention is a toner consumption calculation program for causing a computer to function as each unit included in the above-described image forming apparatus.

  According to the present invention, it is possible to detect toner consumption accurately and early.

1 is a schematic diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. FIG. 2 is a diagram illustrating an example of a hardware configuration of an image forming apparatus according to the present embodiment. It is a figure which shows an example of the functional block of CPU which an engine part has. FIG. 3 is a diagram illustrating an example of functional blocks of the image forming apparatus according to the present embodiment. 7 is a flowchart illustrating a flow of toner consumption count processing. FIG. 6 is a diagram for explaining a method of calculating a toner adhesion amount from dot continuity in a peripheral region. FIG. 6 is a diagram for explaining print image areas divided in the process of FIG. 5. It is a figure which shows AC area | region in the printing image area | region of 1 page. It is a figure which shows the state which divided | segmented the printing image area | region of 1 page into AC area | region. It is a figure for demonstrating the toner consumption of the area | region AC divided | segmented. It is a figure for demonstrating the printing image area | region divided | segmented for every predetermined number of lines. 10 is a flowchart illustrating a flow of a toner consumption amount counting process for a print image area divided every predetermined number of lines.

  Hereinafter, embodiments of the present invention will be described in detail.

<Schematic diagram of image forming apparatus>
FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 includes a developing unit 2 as an image forming unit, a toner cartridge 3, an intermediate transfer belt 4, a secondary transfer driving roller 5, a transfer belt tension roller 6, and a primary transfer. A roller 7, a paper feed tray 8, a paper feed roller 9, a registration roller 10, a secondary transfer roller 11, a fixing device 12, and a paper discharge roller 13 are configured.

  The developing unit 2 includes developing units 2A to 2D, and is provided for each toner color such as black (K), cyan (C), magenta (M), yellow (Y), and the like. Each toner image is formed in 2D.

  Each of the developing units 2A to 2D includes a photosensitive member 14, a charger 15, a developing device 17, and a cleaner blade 18, and around the photosensitive member 14, the charger 15, the developing device 17, and the developing unit 17. The cleaner blade 18 is disposed. The developing units 2A to 2D have the same internal configuration. Further, the exposure device 16 is configured to irradiate the photoconductor 14 with a laser beam 19 corresponding to the image color formed by the developing units 2A to 2D.

  The toner cartridge 3 includes toner cartridges 3A to 3D, and is provided for each toner color of black (K), cyan (C), magenta (M), and yellow (Y), for example.

  The intermediate transfer belt 4 is an endless (endless) belt wound around a secondary transfer driving roller 5 that is rotationally driven and a transfer belt tension roller 6. The primary transfer roller 7 includes primary transfer rollers 7 </ b> A to 7 </ b> D, and transfers the toner images formed on the photoconductors 14 </ b> A to 14 </ b> D to the intermediate transfer belt 4.

  The paper feed tray 8 stacks the paper 20. The paper 20 is conveyed by the paper feed roller 9 and the registration roller 10, and the secondary transfer roller 11 transfers the image formed on the transfer belt 4 to the paper 20. The fixing device 12 fixes the image transferred onto the paper 20. In addition, a paper discharge sensor that detects that the paper 20 has passed is close to the paper discharge roller 13. In addition, a waste toner box 21 is provided to collect toner patterns formed on the transfer belt 4 and toner remaining without being transferred to the paper 20.

  Next, a general operation of the above-described image forming apparatus 1 will be described. When the image forming apparatus 1 forms an image, for example, the outer peripheral surface of the photoreceptor 14A is uniformly charged by the charger 15A, and then exposed by the laser beam 19A emitted from the exposure device 16A to form an electrostatic latent image. To do. The developing unit 17A visualizes the electrostatic latent image with toner and forms a toner image on the photoreceptor 14A.

  The toner image on the photoconductor 14A is transferred onto the transfer belt 4 by the primary transfer roller 7A at a position where the photoconductor 14A and the transfer belt 4 are in contact (primary transfer position), and a toner image is formed on the transfer belt 4. Is done. After the transfer of the toner image is completed, the unnecessary toner remaining on the outer peripheral surface of the photoreceptor 14A is wiped off by the cleaning blade 18 and waits for the next image formation.

  The transfer belt 4 onto which the toner image has been transferred by the developing unit 2A is conveyed to the next developing unit 2B. In the developing unit 2B, a toner image is formed through an image forming process similar to that of the developing unit 2A, and is transferred onto the toner image formed on the transfer belt 4 in a superimposed manner.

  The transfer belt 4 is further conveyed to the next developing units 2C and 2D, and a toner image is transferred by the same operation, and a full-color toner superimposed image is formed on the transfer belt 4. The transfer belt 4 on which the full-color superimposed image is formed is conveyed to the position of the secondary transfer roller 11.

  The paper 20 stored in the paper feed tray 8 is sequentially fed by the paper feed roller 9 and sent by the registration roller 10 at a predetermined timing, and the toner image on the transfer belt 4 is transferred to the paper 20 on the secondary transfer roller 11. Is transferred to.

  The fixing device 12 fixes the toner image on the paper 20 by heat and pressure, and the paper 20 is discharged to the outside by a paper discharge roller 13.

  Each of the developing units 2A to 2D is provided with a remaining toner sensor that detects the remaining amount of toner, and the remaining toner sensor detects the remaining amount of toner in the developing units 2A to 2D. Based on the detected toner remaining amount, toner is supplied from the toner cartridges 3A to 3D to the developing units 2A to 2D, respectively.

<Hardware configuration of image forming apparatus>
Next, the hardware configuration of the image forming apparatus 1 described above will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a hardware configuration of the image forming apparatus according to the present embodiment.

  As shown in FIG. 2, the image forming apparatus 1 is configured to include a controller unit 30 and an engine unit 40. A display unit 31 is connected to the controller unit 30.

  The controller unit 30 is configured to include an I / F unit 32, an image memory unit 33, and a CPU (Central Processing Unit) 34.

  The I / F unit 32 is an interface that enables transmission and reception of data with an external device such as a host computer, for example, and acquires an image signal as print data from the external device or the like.

  The image memory unit 33 stores an image signal acquired from the above-described external device or the like via, for example, the I / F unit 32.

  The CPU 34 controls the entire components of the controller unit 30. Further, the CPU 34 instructs the engine unit 40 to form an image corresponding to the image signal, for example, according to the user instruction content acquired from the display unit 31.

  Here, the display unit 31 connected to the CPU 34 of the controller unit 30 includes, for example, a liquid crystal display. In response to a control command from the CPU 34, the display unit 31 displays an operation guide to the user and a progress status of the image forming operation, a predetermined message notifying the occurrence of an abnormality in the apparatus, the replacement time of a unit such as a toner cartridge, and the like. Is displayed. Further, the display unit 31 receives an instruction regarding image formation from the user.

  The engine unit 40 includes a ROM (Read Only Memory) 41, a RAM (Random Access Memory) 42, a CPU 43, a developing unit 2, a toner cartridge 3, an exposure unit 16, a fixing unit 12, and other I / Os. And a portion 44. The engine unit 40 controls various engine units in accordance with a control command from the CPU 34, and forms an image corresponding to the image signal acquired from the controller unit 30 on the paper 20.

  The ROM 41 stores a calculation program executed by the CPU 43, various data for controlling various engine units, and the like.

  The RAM 42 temporarily stores the calculation results in the CPU 43 and other data.

  The CPU 43 controls the entire components of the engine unit 40. The CPU 43 forms an image by controlling the developing unit 2, the toner cartridge 3, the exposure device 16, the fixing device 12, and the like, for example. The CPU 43 controls input / output of electrical components such as sensors, motors, and clutches connected to the other I / O unit 44.

  The other I / F unit 44 is a general term for one or more devices that perform input / output of control information or data itself with the engine unit 40. Specifically, the other I / O unit 44 is connected to devices necessary for image formation, such as sensors, motors, and clutches other than the developing unit 2, the toner cartridge 3, the exposure device 16, and the fixing device 12.

  As described above, in the present embodiment, the CPU 43 of the engine unit 40 performs control related to image formation of the image forming apparatus 1.

<Functional Configuration of CPU 43 of Engine Unit 40>
Next, each function of the CPU 43 of the engine unit 40 described above will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of a functional block of a CPU included in the engine unit.

  As shown in FIG. 3, the CPU 43 includes an image line detection unit 50, a division line determination unit 51, a dot array division unit 52, a toner consumption amount calculation unit 53, a toner consumption correction amount calculation unit 54, and a toner supply. The control means 55 is comprised.

  The image line detection unit 50 counts the number of input lines of the print dot array corresponding to the print data input for each line from the controller 30.

  The dividing line determination unit 51 determines a dividing line for dividing the print dot array using, for example, a specified value or a predetermined condition. The dividing line determination unit 51, for example, as a predetermined condition, the toner remaining level of the developing units 2A to 2D detected by the above-described toner remaining amount sensor or the image size included in the print data acquired from the controller unit 30 (for example, A4, The dividing line is determined using one or both of the long and the like.

  The dot array dividing unit 52 divides the print dot array based on the number of lines obtained by the image line detecting unit 50 and preset division lines. The dividing line can be set by the dividing line determination unit 51 or the like.

  The toner consumption amount calculation unit 53 calculates the toner consumption amount using the print dot array divided by the dot array division unit 52. For example, the toner consumption amount calculation unit 53 calculates the toner consumption amount of the target print dot in the divided print dot array by the total value of the weight matrix set around the print dot. A method for calculating the weight matrix and the toner consumption will be described later.

  The toner consumption correction amount calculating unit 54 calculates the toner consumption correction amount using the print dot array corresponding to the boundary region of the print dot array divided by the dot array dividing unit 52. The toner consumption correction amount is used, for example, as a correction amount for correcting the shortage of the toner consumption amount calculated by the toner consumption amount calculation unit 53 from the divided print dot array.

  For example, the toner consumption correction amount calculation unit 54 subtracts the target print dot weight from the total value of the weight matrix for the toner consumption amount of the target print dot in the print dot array corresponding to the boundary region described above. To calculate. A method for calculating the toner consumption correction amount will be described later.

  The toner supply control unit 55 performs toner supply control based on the toner consumption amount obtained by the toner consumption amount calculation unit 53 and the toner consumption correction amount obtained by the toner consumption correction amount calculation unit 54.

<Functional Block of Image Forming Apparatus>
Next, a functional block example of the image forming apparatus 1 described above will be described with reference to FIG. FIG. 4 is a diagram illustrating an example of functional blocks of the image forming apparatus according to the present embodiment. Note that the controller unit 30 and the engine unit 40 shown in FIG. 4 schematically show main functions related to toner consumption calculation of the present embodiment.

  As shown in FIG. 4, the controller unit 30 is configured to include an I / F unit 32, a color conversion unit 35, a gradation correction unit 36, and a pulse modulation unit 37. Note that the color conversion unit 35, the gradation correction unit 36, and the pulse modulation unit 37 are functions controlled by the CPU 34.

  When the color conversion unit 35 acquires an image signal as print data from the host computer 50 that instructs image formation output, for example, via the I / F unit 32, the RGB of each pixel in the image corresponding to the acquired image signal. The RGB gradation data indicating the component gradation level is converted into CMYK gradation data indicating the CMYK component gradation level.

  The gradation correction unit 36 performs halftone processing such as correction of γ characteristics of the engine unit 40, error diffusion method, dithering method, and the like on the CMYK gradation data acquired from the color conversion unit 35, thereby generating halftone CMYK gradations. Convert to data. The halftone CMYK gradation data indicates the size of toner dots of CMYK colors to be attached to each pixel and their arrangement signals.

  The pulse modulation unit 37 uses the halftone CMYK gradation data acquired from the gradation correction unit 36 to indicate the ON / OFF state of exposure on the photoconductor 14, that is, a binary value indicating the print dot arrangement on the photoconductor 14. A video signal of data is created and sequentially output to the engine unit 40 in units of one line.

  As shown in FIG. 4, the CPU 43 of the engine unit 40 includes changeover switches A to C, video signal buffers A to C, toner consumption conversion units A to C, and counters A to C. Using these configurations, the above-described image line detection unit 50, division line determination unit 51, dot array division unit 52, toner consumption amount calculation unit 53, and toner consumption correction amount calculation unit 54 are caused to function. Control.

  The change-over switches A to C switch ON / OFF of the respective switches, and the video signals indicating the print dot arrangement obtained in units of one line from the pulse modulation unit 37 of the controller unit 30 are transmitted to at least the video signal buffers A to C. Sort into one. Note that ON / OFF switching of each of the switches A to C can be performed for each input line by, for example, the dot array dividing unit 52 or the like.

  The video signal buffers A to C temporarily store the video signals distributed by the changeover switches A to C.

  The toner adhesion amount conversion units A to C, based on the video signals stored in the video signal buffers A to C, for the print dots to be calculated, peripheral areas in the main scanning direction and the sub scanning direction centering on the printing dots The dot continuity is converted into the toner adhesion amount. The toner adhesion amount conversion units A and B correspond to, for example, the toner consumption amount calculation unit 53 shown in FIG. 3, and the toner adhesion amount conversion unit C corresponds to, for example, the toner consumption correction amount calculation unit 54 shown in FIG. .

  The counters A to C accumulate the toner adhesion amounts acquired from the toner adhesion amount conversion units A to C. Thus, the counter A to the counter C hold the toner consumption counted based on the two-dimensional counting technique of the video signal stored in the video signal buffers A to C.

<About toner consumption count processing>
Next, the flow of the toner consumption counting process counted by the counter A to the counter C will be described with reference to FIG. FIG. 5 is a flowchart showing the flow of the toner consumption amount counting process.

  In the example of FIG. 5, the toner consumption amount counting process in units of one page will be described. In the case of continuous printing, this process is repeatedly performed in units of one page. Further, in the example of FIG. 5, the toner consumption is counted by dividing one page into two equal parts.

  As shown in FIG. 5, the image line detection means 50 determines whether or not the video signal output from the controller unit 30 is input (S10), and determines that the video signal is input (YES in S10). The counting of the number of lines of the input video signal is started (S11).

  Next, the changeover switch A is turned ON (connected state) (S12), and accumulation of video signals in the video signal buffer A is started. If the image line detection unit 50 determines that no video signal is input (NO in S10), it continues the process of S10.

  The dot array dividing means 52 determines whether or not the number of input lines counted by the image line detection means 50 is a specified value-1 (specified value-1 = number of input lines) (S13).

  When the dot array dividing unit 52 determines that the number of input lines is the specified value −1 (YES in S13), the dot switch 52 turns on the changeover switch C (S14) and starts storing the video signal in the video signal buffer C. To do. At this time, the video signal is continuously stored in the video signal buffer A. Accordingly, in this case, the change-over switches A and C are turned on, and the video signals acquired from the controller unit 30 are output and stored in the video signal buffers A and C.

  If it is determined that the number of input lines is not the prescribed value -1 (NO in S13), the process returns to S13 and waits until the number of input lines becomes the prescribed value -1.

  Here, the “specified value” indicates, for example, a division line serving as a reference for dividing the print dot array corresponding to the print data of one page, and a fixed value or the like may be set in advance. It may be arbitrarily set by the determination means 51. As shown in the example of FIG. 5, when one page is divided into two divided areas, the “specified value” is a value obtained by multiplying the total number of lines of one page by ½. The “specified value −1” is a value obtained by subtracting one line from a value obtained by multiplying the total number of lines on one page by 1/2 (a value one line before a value obtained by multiplying the total number of lines by 1/2). Indicates.

  Next, the dot array dividing unit 52 determines whether or not the number of input lines counted by the image line detecting unit 50 is a specified value (specified value = number of input lines) (S15).

  When the dot array dividing means 52 determines that the number of input lines is a specified value (YES in S15), it outputs the video signal of the input line determined to be the specified value (specified value line) to the video signal buffer A. Thereafter, the changeover switch A is turned off (open state), and the changeover switch B is turned on (S16). Here, the video signal of the specified value line is continuously output to the video signal buffer C, and the video signal acquired from the controller unit 30 is accumulated in the video signal buffers A and C.

  If it is determined that the number of input lines is not the specified value (NO in S15), the process returns to S15 and waits until the number of input lines reaches the specified value.

  In this manner, the video signal from the first line (first) to the specified value line of the print image of the first page is temporarily stored in the video signal buffer A. The toner consumption amount conversion unit A converts the primarily stored video signal into a toner consumption amount, and the counter A accumulates the toner consumption amount of the video signal primarily stored in the video signal buffer A (S17).

  When the toner consumption amount is accumulated in the counter A, the accumulated value is recorded in the RAM 42. As a result, it is possible to update the toner consumption during the formation of the electrostatic latent image for one page. Further, the toner replenishment control means 55 may control to replenish toner from the toner cartridge 3 to the developing unit 2 based on the value accumulated in the counter A.

  Next, the dot array dividing means 52 determines whether or not the number of input lines is a preset specified value + 1 (specified value + 1 = number of input lines) (S18). Here, “specified value + 1” means a value obtained by adding one line to a value obtained by multiplying the total number of lines of one page by 1/2 (a value after one line from a value obtained by multiplying the total number of lines by 1/2). Indicates.

  When the dot array dividing unit 52 determines that the number of input lines is the specified value +1 (YES in S18), the video signal buffer C receives the video signal of the input line determined to be the specified value +1 (specified value + 1 line). Are output, the input selector switch C is turned OFF (S19). Here, the video signal of the specified value + 1 line is continuously output to the video signal buffer B, and the video signal acquired from the controller unit 30 is stored in the video signal buffers B and C.

  If it is determined that the number of input lines is not the specified value +1 (NO in S18), the process returns to S18 and waits until the number of input lines reaches the specified value +1.

  In this manner, the video signal for two lines of the specified value line and the specified value + 1 line of the print image of the first page is temporarily stored in the video signal buffer C. The toner consumption amount conversion unit C converts the primary stored video signal into a toner consumption amount, and the counter C accumulates the toner consumption amount of the video signal primarily stored in the video signal buffer C (S20).

  When the toner consumption amount is accumulated in the counter C, the accumulated value is recorded in the RAM 42. As a result, it is possible to update the toner consumption during the formation of the electrostatic latent image for one page. Further, the toner replenishment control means 55 may perform control so that toner is replenished from the toner cartridge 3 to the developing unit 2 based on the value accumulated in the counter C.

  In the present embodiment, the value accumulated in the counter C is used as a correction amount for correcting the shortage of toner consumption that is insufficient in the counter A and the counter B, respectively.

  Next, the dot array dividing means 52 determines whether or not the number of input lines is the total number of lines for one page (total number of lines = number of input lines) (S21). If it is determined that the number of input lines is not the total number of lines (NO in S21), the process returns to S21 and waits until the number of input lines reaches the total number of lines.

  When the dot array dividing unit 52 determines that the number of input lines is the total number of lines (the last line of one page) (YES in S21), the video signal buffer B outputs the video signal of the input line determined to be the last line. , The changeover switch B is turned OFF (S22). Here, the video signal acquired from the controller unit 30 is accumulated in the video signal buffer B.

  In this way, the video signal from the specified value + 1 line to the last line of the print image of the first page is temporarily stored in the video signal buffer B. The toner consumption amount conversion unit B converts the primary stored video signal into a toner consumption amount, and the count B is integrated with the toner consumption amount of the video signal primarily stored in the video signal buffer B (S23).

  When the toner consumption amount is accumulated in the counter B, the accumulated value is recorded in the RAM 42. Thereby, the toner consumption amount for one page is determined in the engine unit 40. Further, the toner replenishment control means 55 may control to replenish toner from the toner cartridge 3 to the developing unit 2 based on the value accumulated in the counter B.

  Next, the CPU 43 determines whether or not to end the process (S24), and if it is determined not to end the process (eg, in the case of continuous printing) (NO in S24), the CPU 43 buffers the video signal buffers A to C. The video signal is cleared, the values held in the counts A to C are cleared, the process returns to S11, and the subsequent processes are continued.

  If it is determined that the process is to be terminated (YES in S24), the video signals in the video signal buffers A to C are cleared, the values of the counts A to C are cleared, and the process is terminated.

  As described above, in this embodiment, since the toner consumption amount and the toner consumption correction amount by the two-dimensional toner consumption counting technique can be obtained for each divided area, the completion of the formation of the electrostatic latent image for one page is awaited. Therefore, it is possible to obtain the toner consumption amount for each divided area with high accuracy at an early stage.

<Conversion method to toner consumption>
Next, as an example of the conversion method of the video signal temporarily stored in the video signal buffers A to C described above into the toner consumption amount, a method for calculating the toner consumption amount of the print dot to be calculated will be described with reference to FIG. To do.

  FIG. 6 is a diagram for explaining a method of calculating the toner consumption amount from the dot continuity in the peripheral area. In the example of FIG. 6, for example, a 3 × 3 dot weight matrix is defined in advance centering on a print dot to be calculated. Here, the weight matrix takes into account fluctuations in the toner adhesion amount due to the overlap (dot continuity) of the light beam in the peripheral area of the print dot to be calculated, and in advance the peripheral area of the target print dot. A weighting coefficient is set for dots. Note that the weighting coefficient varies depending on, for example, the type of photosensitive member and toner used, the model, and the like.

  When calculating the toner consumption of the print dot to be calculated, for example, using the weighting factor set by the weighting matrix and the exposure information (existence of exposure), for example, the sum of the products of the weighting factor and the presence / absence of exposure is attached to the toner. Amount (toner consumption).

  That is, the toner consumption amount of the print dot to be calculated (the dot at the center of the weight matrix) is the weight coefficient (weight (i, j): natural number) of the peripheral dots set in the weight matrix as shown in FIG. Calculated by the sum of products of exposure (exposure (i, j): exposure “1”, exposure “0”), matrix calculation formula (Σ (weight (i, j) × exposure (i, j))) be able to.

  In this embodiment, the toner consumption amount calculation unit 53 and the toner consumption correction amount calculation unit 54 calculate the toner consumption amount by the above-described two-dimensional toner consumption counting technique using the weight matrix. For example, when calculating the end of the print image area temporarily stored in the video signal buffers A to C, the peripheral dots outside the area are calculated as “0” without exposure. Further, the amount of toner to be developed is proportional to the amount of exposure of the photoconductor 14, but is saturated when it exceeds a certain level.

  Therefore, the toner consumption value of the target print dot is corrected by providing an upper limit value or a fixed offset value for the toner consumption value calculated in advance by the matrix calculation formula. May be performed. Note that the toner consumption calculation method in the present embodiment is not limited to this.

<Regarding the print image area divided by the specified value line>
Next, the print image area temporarily stored in the video signal buffers A to C when the print image area is divided in the process shown in FIG. 5 will be described with reference to FIG. FIG. 7 is a diagram for explaining print image regions divided in the process of FIG.

  As shown in FIG. 7, in the process of FIG. 5, a predetermined value line is provided in advance, and a print image area of one page is divided by the predetermined value line. Therefore, for example, in the video signal buffer A, the video signal from the first line (first) to the specified value line, for example, the A area in the print image area of one page is temporarily stored.

  Further, in the video signal buffer B, for example, a video signal from a predetermined value line + 1 line to the last line as the B area among the print image areas of one page is temporarily stored.

  Further, in the video signal buffer C, video signals for two lines, for example, a defined value line and a defined value + 1 line as the C region in the print image region of the first page are temporarily stored. As described above, the video signal buffer C primarily stores the video signals for two lines included in the boundary area (C area) divided into the A area and the B area.

  That is, the video signal buffer C includes a signal that overlaps the video signal of the specified value line stored in the video signal buffer A and a signal that overlaps the signal of the specified value line + 1 line stored in the video signal buffer B. Is memorized.

<Regarding the calculation method of the toner consumption of each print image area divided by the specified value line>
Next, a method for calculating the toner consumption amount of each print image area obtained by dividing the print image area of one page by the above-described processing of FIG. 5 will be described with reference to FIGS. FIG. 8 is a diagram showing areas A to C in the print image area of one page. FIG. 9 is a diagram showing a state in which the print image area of one page is divided into areas A to C. FIG. 10 is a diagram for explaining the toner consumption amount of the divided A to C regions.

  The print image area of one page shown in FIG. 8 is configured with an image size of 10 dots in the main scanning direction and 20 dots in the sub-scanning direction, for example. Each dot indicates the presence or absence of exposure (exposed “●”, unexposed “◯”).

  As shown in FIG. 8, for example, when the toner consumption amount is calculated by dividing a print image area of one page into two equal parts, three areas A to C are used. Specifically, each of the A area and the B area is an area obtained by dividing the print image area of one page into two, and the C area is an area where the boundary areas of the A area and the B area overlap each other (the A area and the B area). Boundary area 2 lines).

  In the example of FIG. 8, the 10th line in the sub-scanning direction is the specified value line. Therefore, the A area includes the first to tenth lines (specified value lines) in the sub-scanning direction, and the B area includes the eleventh line (specified value + 1 line) to the twentieth lines in the sub-scanning direction. , C region includes the tenth line (specified value line) and the eleventh line (specified value + 1 line) in the sub-scanning direction.

  Here, FIG. 9 shows separately the information (video signals in the areas A to C) stored in the video signal buffers A to C, respectively. In the example of FIG. 9, in consideration of the case where each region end of the A region to the C region is a print dot to be calculated, for example, a state in which a non-exposure region is artificially added to the outer periphery of each region end Is shown.

  As described above, when calculating the toner consumption amount of each dot, since the 3 × 3 weight matrix centering on the print dot to be calculated shown in FIG. 6 is used, it is simply divided into the area A and the area B. The toner consumption obtained from the area will be insufficient.

  For example, FIG. 10A shows the 8th to 10th lines in the sub-scanning direction included in the video signal buffer A, and FIG. 10B shows 11 lines in the sub-scanning direction included in the video signal buffer B. The thirteenth line from the eye is shown.

  As shown in FIG. 10A, for example, the print dot (10, 3) to be calculated is a dot included in the 10th line, but the information in the video signal buffer A contains the 11th line in the sub-scanning direction. Information (weight coefficient and exposure information for each dot) is insufficient.

  As shown in FIG. 10B, for example, the print dot (11, 3) to be calculated is a dot included in the eleventh line, but the information in the video signal buffer B contains 10 lines in the sub-scanning direction. Eye information (weight coefficient and exposure information for each dot) is insufficient.

  Therefore, when the toner consumption amount of the divided areas A and B is simply calculated, the peripheral area with respect to the dots that are the boundaries of the divided areas (dots in the 10th and 11th lines in the example of FIG. 9). Dot continuity is not considered.

  Therefore, the deficiencies are calculated using the video signal buffer C that stores the video signals of the dots in the boundary areas of the divided areas (the part corresponding to the area C in the example of FIG. 9). The video signal buffer C includes weighting coefficients and exposure information for the lines that are insufficient in the video signal buffer A and the video signal buffer B, respectively.

  Specifically, the toner consumption correction amount calculating means 54 calculates the toner consumption amount of the video signal buffer C = Σ (weight (i, j) × exposure (i, j)) − (Σ (weight (2, j) × exposure (2, j))).

  Note that (Σ (weight (2, j) × exposure (2, j)) in this equation calculates the toner consumption amount of the video signal buffer A or the video signal buffer B using the information of the video signal buffer C. This is for subtracting the weighting coefficient and exposure information for the overlapping lines.

  When the above-described equation is used, the deficiency of the 10th line (that is, information on the 11th line) of the video signal buffer A shown in FIG. 10C is calculated as follows.

  As shown in FIG. 10C, the shortage of the print dots (10, 3) to be calculated is 9 lines (Σ (weight (1, j) × exposure (1, j)) in the sub-scanning direction (1). )) + 10 lines in the sub-scanning direction (2) (Σ (weight (2, j) × exposure (2, j)) + 11 lines in the sub-scanning direction (3) (Σ (weight (3, j)) X exposure (3, j))-10 lines (Σ (weight (2, j) x exposure (2, j))) in the sub-scanning direction (2).

  As described above, 10 lines in the sub-scanning direction (2) shown in FIG. 10C are subtracted because they have already been calculated in the video signal buffer A when calculating the print dots (10, 3) to be calculated. To do. The ninth line in the sub-scanning direction (1) shown in FIG. 10C is calculated as “0” without exposure (the nine lines are already calculated in the video signal buffer A).

  As a result of the above, as a shortage of print dots (10, 3) to be investigated, 11 lines (Σ (weight (3, j) × exposure (3)) in the sub-scanning direction (3) shown in FIG. , J)) (the added value of the 11th line with respect to the 10th line) is calculated.

  Similarly, the shortage of the 11th line (that is, information on the 10th line) of the video signal buffer B shown in FIG. 10D is calculated as follows.

  As shown in FIG. 9D, the shortage of print dots (11, 3) to be calculated is 10 lines in the sub-scanning direction (1) (Σ (weight (1, j) × exposure (1, j )) + 11 lines in the sub-scanning direction (2) (Σ (weight (2, j) × exposure (2, j)) + 12 lines in the sub-scanning direction (3) (Σ (weight (3, j)) X exposure (3, j))-11 lines (Σ (weight (2, j) x exposure (2, j))) in the sub-scanning direction (2).

  As described above, 11 lines in the sub-scanning direction (2) shown in FIG. 10D are subtracted because they have already been calculated in the video signal buffer B when calculating the print dots (11, 3) to be calculated. To do. Further, the 12th line in the sub-scanning direction (3) shown in FIG. 10D is calculated as “0” without exposure (the 12th line is already calculated in the video signal buffer B).

  As a result of the above, as a shortage of print dots (11, 3) to be investigated, 10 lines (Σ (weight (1, j) × exposure (1)) in the sub-scanning direction (1) shown in FIG. , J)) (that is, the added value of the 10th line with respect to the 11th line) is calculated.

  As described above, the toner consumption amount in the video signal buffer A or the video signal buffer B is calculated by Σ (weight (i, j) × exposure (i, j)), and the toner consumption amount in the video signal buffer C is For each line, Σ (weight (i, j) × exposure (i, j)) − (Σ (weight (2, j) × exposure (2, j))) is used.

<Regarding Print Image Area Divided for Each Predetermined Number of Lines>
Next, a print image area that is temporarily stored in the video signal buffers A to C when the print image area is divided for each predetermined number of lines will be described with reference to FIG. FIG. 11 is a diagram for explaining a print image area divided every predetermined number of lines.

  In the example of FIG. 11, for example, based on the remaining toner level detected by the remaining toner sensor, the image size (A4, B4, long, etc.) included in the print data acquired from the controller unit 30, and the like. The division line determination unit 51 determines a predetermined number of lines for dividing the print image area of one page.

  As a result, the update period of the toner consumption recorded in the RAM 42 can be freely determined, and the amount of memory stored in the video signal buffers A and B can be reduced as the number of divisions is increased.

  As shown in FIG. 11, when a print image area divided for each predetermined number of lines is used, the total number of lines in one page is divided for each predetermined number of lines, and the video signal buffer is divided for each divided predetermined number of lines. A and video signal buffer B are alternately temporarily stored. For example, the video signal buffer A stores video signals from the first line to Mod (number of input lines, division line period) = 0. “Mod (number of input lines, division line cycle) = 0” means that the remainder when the number of input lines is divided by the number of division lines is zero.

  The video signal B stores video signals from Mod (number of input lines, division line period) = division line period + 1 to Mod (number of input lines, division line period × 2) = 0. As described above, the video signal buffer A and the video signal buffer B alternately store the signals of the areas divided for each predetermined number of lines.

  In addition, when the video signal buffer C stores the video signal buffer A and the video signal buffer B alternately, the video signal for two lines in the boundary region is stored.

<Regarding Toner Consumption Count Processing of Print Image Area Divided for Each Predetermined Number of Lines>
Next, the flow of toner consumption counting processing counted by the counters A to C for a print image area divided for each predetermined number of lines shown in FIG. 11 will be described with reference to FIG. FIG. 12 is a flowchart showing the flow of the toner consumption amount counting process for the print image area divided every predetermined number of lines.

  In the example of FIG. 12, the toner consumption amount counting process for each page will be described. In the case of continuous printing, this process may be repeatedly performed for each page.

  As shown in FIG. 12, the image line detection means 50 determines whether or not the video signal output from the controller unit 30 has been input (S30). If it is determined that a video signal has been input (YES in S30), the division line determination means 51 determines the number of line periods in which the print image area of one page is divided, or a predetermined number of lines serving as a reference for dividing the print image area. Determine (S31).

  Here, the division line determination means 51 determines the predetermined number of lines as the division lines according to the status of the apparatus, for example. Specifically, the divided line determination unit 51 may use a predetermined number of lines as a cycle, the remaining toner level detected by the remaining toner sensor (near end, etc.), and the print data acquired from the controller unit 30. The predetermined number of lines may be determined according to the situation such as the image size (for example, A4, B4, long, etc.) included in the image.

  If it is determined that no video signal is input (NO in S30), the process waits until the video signal is input.

  Next, the image line detection means 50 starts counting the number of lines of the input video signal (S32), and determines whether or not the number of input lines has reached the total number of lines for one page (S33). When it is determined that the number of lines for one page has not been reached (NO in S33), the changeover switch A is turned on (S34), and accumulation in the video signal buffer A is started. If it is determined that the number of lines for one page has been reached (YES in S33), the process ends.

  Next, the dot array dividing means 52 determines whether or not the number of input lines is Mod (number of input lines, division line period (predetermined number of lines)) = 0 (S35), and the number of input lines is Mod (number of input lines, When it is determined that the division line period) = 0 (YES in S35), after the video signal of the input line determined to be Mod (number of input lines, division line period) = 0 is output to the video signal buffer A, The changeover switch A is turned off and the changeover switch B is turned on (S36), and accumulation of video signals in the video signal buffer B is started.

  In this way, video signals from the first line (first) of the print image of the first page to Mod (number of input lines, division line cycle) = 0 are temporarily stored in the video signal buffer A. The toner consumption amount conversion unit A converts the primarily stored video signal into a toner consumption amount, and the counter A accumulates the toner consumption amount of the video signal primarily stored in the video signal buffer A (S37). After the process of S37, the integrated value may be recorded in the RAM 42, and the toner supply control unit 55 may supply the toner based on the integrated value.

  Next, the video signal buffer A is cleared, and the counter A is cleared (S38). In the process of S35, when it is determined that Mod (number of input lines, divided line period) = 0 is not satisfied (NO in S35), the number of input lines is counted, and Mod (number of input lines, divided line period) = 0. (The process described later is not performed).

  Next, the dot array dividing means 52 determines whether or not the number of input lines is Mod (number of input lines, divided line period × 2) = 0 (S39), and the number of input lines is Mod (number of input lines, divided line period). If it is determined that x2) = 0 (YES in S39), after the video signal of the input line determined to be Mod (number of input lines, divided line period x2) = 0 is output to the video signal buffer B Then, the changeover switch B is turned OFF (S40).

  In this way, Mod (number of input lines, divided line cycle) of the first page printed image in the video signal buffer B = divided line cycle + 1 line to Mod (number of input lines, divided line cycle × 2) = 0. The video signal is temporarily stored. The toner consumption amount conversion unit B converts the video signal temporarily stored into toner consumption amount, and the toner consumption amount of the video signal primarily stored in the video signal buffer B is accumulated in the counter B (S41). Note that the integrated value may be recorded in the RAM 42 after the processing of S41, and the toner supply control unit 55 may supply the toner based on the integrated value.

  Next, the video signal buffer B is cleared, the counter B is cleared (S42), and the process returns to S33.

  That is, in the processing of S33 to S42, among the divided areas of one page, the odd-numbered area and the even-numbered area are alternately assigned to the video signal buffer A and the video signal buffer B, respectively, and the respective toner consumption amounts. And is integrated by counters A and B. Here, in order to accurately detect the toner consumption amount, the toner consumption amount calculation processing in the divided boundary region is necessary. Therefore, the processing using the video signal buffer C and the counter C is performed in the above-described steps S33 to S42. Perform in parallel with processing.

  Specifically, as shown in FIG. 12, while starting the count of the number of lines in the process of S <b> 32, the dot array dividing unit 52 determines that the number of input lines is Mod (number of input lines, divided line period (predetermined number of lines) ) = Divided line period-1 or not (S43).

  When the dot array dividing means 52 determines that the number of input lines is the division period -1 (YES in S43), the switch C is turned ON (S44), and the video of the input line determined to be the division line period -1 The accumulation of the signal in the video signal buffer C is started. If it is determined that the number of input lines is not the division period -1 (NO in S43), the process returns to S43 and waits until the number of input lines reaches the division period -1.

  Next, the dot array dividing means 52 determines whether or not the number of input lines is Mod (number of input lines, divided line period (predetermined number of lines)) = divided line period + 1 (S45). When the dot array dividing means 52 determines that the number of input lines is the division period + 1 (in S45, YES), after outputting the video signal of the input line determined to be the division period + 1 line to the video signal buffer C, the switching is performed. The switch C is turned off (S46).

  In this way, Mod (input line number, divided line cycle) of the print image of the first page in the video signal buffer C = divided line cycle-1 and Mod (number of input lines, divided line cycle) = divided line cycle + 1. The video signal is temporarily stored. The toner consumption amount conversion unit C converts the primarily stored video signal into a toner consumption amount, and the toner consumption amount of the video signal primarily stored in the video buffer C is integrated into the counter C (S47).

  Next, the video signal buffer C is cleared, the counter C is cleared (S48), and the process returns to S43.

  If it is determined that the number of input lines is not the division period +1 (NO in S45), the process returns to S37 and waits until the number of input lines becomes the division period +1.

  In this way, in the processing of FIG. 12, the toner consumption can be obtained with high accuracy by performing the counting in the counter C in parallel with the counting in the counters A and B. Further, it is possible to divide the area according to the situation such as the remaining toner level and the image size, and to freely determine the period for calculating the toner consumption.

  As described above, according to the embodiment of the present invention, it is possible to detect toner consumption accurately and early. That is, since the toner consumption amount and the toner consumption correction amount by the two-dimensional toner consumption counting technology can be obtained for each divided area, the division can be performed quickly and accurately without waiting for the completion of formation of the electrostatic latent image for one page. Thus, it is possible to obtain the toner consumption amount for each region.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Can be changed.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Developing unit 3 Toner cartridge 4 Intermediate transfer belt 5 Secondary transfer driving roller 6 Transfer belt tension roller 7 Primary transfer roller 8 Paper feed tray 9 Paper feed roller 10 Registration roller 11 Secondary transfer roller 12 Fixing device 13 Paper roller 14 Photoconductor 15 Charger 16 Exposure unit 17 Development unit 18 Cleaner blade 21 Waste toner box 30 Controller unit 31 Display unit 32 I / F unit 33 Image memory 35 Color conversion unit 36 Gradation correction unit 37 Pulse modulation unit 34, 43 CPU
40 Engine part 41 ROM
42 RAM
44 Other I / O section 50 Image line detection means 51 Divided line determination means 52 Dot array division means 53 Toner consumption calculation means 54 Toner consumption correction quantity calculation means 55 Toner supply control means

JP 2009-300832 A

Claims (7)

An image forming apparatus that calculates a toner consumption amount based on a print dot array corresponding to input print data,
Image line detection means for counting the number of input lines of the print dot array;
A toner consumption calculating means for calculating toner consumption using information of peripheral dots centered on the printing dots in the print dot array;
Based on the number of lines obtained by the image line detection means and a preset division line as a reference for division , the print dot array includes a predetermined number of lines with the division line as a boundary. Divided into a first region and a second region,
A boundary area including a specified value line before the boundary in the first area and a specified value + 1 line that is a peripheral dot outside the specified value line; a specified value + 1 line after the boundary in the second area; and A dot array dividing means for defining a third region that overlaps a boundary region including a prescribed value line that is a peripheral dot outside the prescribed value + 1 line ;
A toner consumption correction amount calculating means for calculating a toner consumption correction amount using the print dot array corresponding to the third region in the print dot array ;
The toner consumption calculation means corresponds to the first area of the divided print dot array, and the predetermined value + 1 that is a peripheral dot outside the specified value line in the specified value line before the boundary. Calculate the first toner consumption that lacks line information ,
The toner consumption amount calculation means corresponds to the second region, and the specified value + 1 line after the boundary lacks information on the specified value line that is a peripheral dot outside the specified value + 1 line. calculating a second toner consumption are,
The toner consumption correction amount calculating unit is configured to obtain, as the toner consumption correction amount corresponding to the third area, a peripheral area outside the specified value line in the specified value line before the boundary corresponding to the first area. The shortage of information of the prescribed value + 1 line that is a dot, and the prescribed value that is a peripheral dot outside the prescribed value + 1 line in the prescribed value + 1 line after the boundary corresponding to the second region Calculate the shortage of information on the line,
The toner consumption amount calculating means calculates the toner consumption amount corresponding to the input print data, using the first toner consumption amount, the second toner consumption amount, and the toner consumption correction amount. ,
An image forming apparatus. The print dot array is divided by comparing one or both of the remaining toner level and the image size included in the print data with a predetermined value or predetermined condition for the remaining toner level and the image size set in advance. The image forming apparatus according to claim 1, further comprising a division line determination unit that determines the division line for the purpose.   A peripheral dot set around the print dot is a weight matrix, and the information of the peripheral dot includes a weight and an exposure for calculating the weight matrix.
  The image forming apparatus according to claim 1. The toner consumption correction amount calculating means includes:
The toner consumption correction amount is calculated by subtracting the weight of the print dot from the total value of the weight matrix of the third region .
The image forming apparatus according to claim 3. Toner supply control means for performing toner supply control based on a toner consumption amount obtained by the toner consumption amount calculation means and a toner consumption correction amount obtained by the toner consumption correction amount calculation means;
The image forming apparatus according to claim 1. A toner consumption amount calculation method in an image forming apparatus for calculating a toner consumption amount based on a print dot arrangement corresponding to input print data,
An image line detection procedure for counting the number of input lines of the print dot array;
Based on the number of lines obtained by the image line detection procedure and a preset division line as a reference for division , the print dot array includes a predetermined number of lines with the division line as a boundary. Divided into a first region and a second region,
A boundary area including a specified value line before the boundary in the first area and a specified value + 1 line that is a peripheral dot outside the specified value line; a specified value + 1 line after the boundary in the second area; and A dot array dividing means for defining a third region that overlaps a boundary region including a prescribed value line that is a peripheral dot outside the prescribed value + 1 line ;
In the print dot arrangement , a toner consumption calculation procedure for calculating toner consumption using information on peripheral dots centered on the print dots ;
A toner consumption correction amount calculating procedure for calculating a toner consumption correction amount using the print dot array corresponding to the third region in the print dot array ;
The toner consumption correction amount calculation procedure is as follows:
The toner consumption calculation procedure is as follows:
Corresponding to the first area of the divided print dot array, the specified value line before the boundary lacks information on the specified value + 1 line which is a peripheral dot outside the specified value line. A procedure for calculating a first toner consumption amount ;
The toner consumption calculation procedure corresponds to the second area, and information on the specified value line that is a peripheral dot outside the specified value + 1 line is insufficient in the specified value + 1 line after the boundary. And calculating a second toner consumption amount
The toner consumption correction amount calculation procedure is as follows:
As the toner consumption correction amount corresponding to the third area, in the specified value line before the boundary corresponding to the first area, the specified value + 1 line which is a peripheral dot outside the specified value line. Information deficiency, and in the specified value + 1 line after the boundary corresponding to the second area, the deficiency of the information in the specified value line which is a peripheral dot outside the specified value + 1 line. Including a procedure for calculating each,
The toner consumption amount calculation procedure calculates the toner consumption amount corresponding to the input print data using the first toner consumption amount, the second toner consumption amount, and the toner consumption correction amount. Including further steps,
And a toner consumption calculation method.   A toner consumption calculation program for causing a computer to function as each unit included in the image forming apparatus according to any one of claims 1 to 5.

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