JP6229297B2 - Optical scanning apparatus, image forming apparatus, system, and management method - Google Patents

Description

  The present invention relates to an optical scanning apparatus, an image forming apparatus, a system, and a management method, and more particularly, an optical scanning apparatus having an optical deflector, an image forming apparatus including the optical scanning apparatus, a system including the optical deflector, and the The present invention relates to a system management method.

  An image forming apparatus such as a digital multifunction peripheral or a laser printer includes an optical scanning device that scans the surface of a photosensitive drum by deflecting light emitted from a light source by an optical deflector having a rotating polygon mirror.

  The optical scanning device includes a synchronization detection sensor that receives light before starting writing at a predetermined position in order to make the writing start position in the main scanning direction on the surface of the photosensitive drum the same among a plurality of scanning lines. Yes.

  By the way, Patent Document 1 discloses a hybrid diagnostic system for diagnosing a printer, a photocopier, a scanner, a facsimile machine, and the like.

  Patent Document 2 discloses a failure diagnosis system that determines the cause of a failure of an image forming apparatus via a network.

  However, in the diagnostic systems disclosed in Patent Document 1 and Patent Document 2, it is impossible to know an abnormality such as an initial defect or a change with time of the optical deflector.

The present invention relates to an optical scanning device that scans a surface to be scanned with light emitted from a light source and reflected by a rotary polygon mirror of an optical deflector, and a light receiver that receives light reflected by each mirror surface of the rotary polygon mirror; A processing device for obtaining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on the output of the light receiver, and determining whether there is an abnormality in the optical deflector , The processing device obtains a first variation that is a variation in time interval of the light reception timing, obtains a first rotation unevenness from a time required for one rotation of the rotary polygon mirror, and determines the first variation from the first variation. The second variation in which the rotation unevenness is removed is obtained, and the second rotation unevenness including a rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror is obtained from the first variation and the second variation. in the optical scanning device for determining That.

  According to the optical scanning device of the present invention, it is possible to know the abnormality of the optical deflector.

1 is a diagram illustrating a schematic configuration of a color printer according to an embodiment of the present invention. FIG. 2 is a diagram (part 1) for explaining an optical scanning device 2010A in FIG. FIG. 3 is a diagram (part 2) for explaining the optical scanning device 2010A in FIG. It is a timing chart for demonstrating the relationship between a synchronous detection signal and a write start timing. It is a timing chart for demonstrating a pseudo synchronous signal. It is a figure for demonstrating each deflection | deviation reflective surface and the mark M of a polygon mirror. It is a figure for demonstrating a surface specific sensor. It is a figure for demonstrating a surface specific signal. It is a timing chart for demonstrating the relationship between a surface specific signal and a synchronous detection signal. It is a figure for demonstrating the distance A from the rotation center in a polygon mirror to a deflection | deviation reflective surface. It is a figure for demonstrating angle (theta) which two deflection | deviation reflective surfaces adjacent to each other in a polygon mirror make. It is a flowchart (the 1) for demonstrating an abnormality test process. It is a flowchart (the 2) for demonstrating abnormality inspection processing. It is a figure for demonstrating a time interval. It is a figure for explaining an example of the 1st variation. It is the figure which expanded a part of FIG. It is FIG. (1) for demonstrating the time required for one rotation of a polygon mirror. It is FIG. (2) for demonstrating the time required for one rotation of a polygon mirror. It is a figure for demonstrating the 1st rotation nonuniformity. It is the figure which expanded a part of FIG. It is a figure for demonstrating an example of the 2nd dispersion | variation. It is the figure which expanded a part of FIG. It is FIG. (1) for demonstrating an example of the isolate | separated 2nd dispersion | variation. It is FIG. (2) for demonstrating an example of the isolate | separated 2nd dispersion | variation. It is FIG. (3) for demonstrating an example of the isolate | separated 2nd dispersion | variation. It is FIG. (4) for demonstrating an example of the isolate | separated 2nd dispersion | variation. It is a figure for demonstrating an example of the 2nd rotation nonuniformity. It is a figure for demonstrating an example of the 1st rotation nonuniformity. It is a figure for demonstrating an example of 3rd rotation unevenness. FIG. 2 is a diagram (part 1) for explaining an optical scanning device 2010B in FIG. FIG. 3 is a second diagram for explaining the optical scanning device 2010B in FIG. 1; It is a figure for demonstrating the example 1 of a judgment apparatus. It is a figure for demonstrating the example 2 of a judgment apparatus. It is a figure for demonstrating the modification 1 of an optical scanning device. It is FIG. (1) for demonstrating the modification 2 of an optical scanning device. It is FIG. (2) for demonstrating the modification 2 of an optical scanning device.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a color printer 2000 according to an embodiment.

  The color printer 2000 is a tandem multicolor printer that forms a full-color image by superimposing four colors (black, cyan, magenta, and yellow), and includes two optical scanning devices (2010A, 2010B), four Photosensitive drums (2030a, 2030b, 2030c, 2030d), four cleaning units (2031a, 2031b, 2031c, 2031d), four charging devices (2032a, 2032b, 2032c, 2032d), and four developing rollers (2033a, 2033b, 2033c, 2033d), transfer belt 2040, transfer roller 2042, fixing roller 2050, paper feed roller 2054, paper discharge roller 2058, paper feed tray 2060, paper discharge tray 2070, communication control device 2080, operation panel (not shown), and A printer control device 2090 for totally controlling the above elements.

  The communication control device 2080 controls bidirectional communication with other devices via a network such as a LAN, a public line, and the Internet.

  The printer control device 2090 includes a CPU, a program written in a code decipherable by the CPU, a ROM storing various data used when executing the program, a RAM as a working memory, an analog signal An A / D converter for converting the signal into a digital signal. The printer control apparatus 2090 controls each unit in response to a request from another apparatus.

  The operation panel has a plurality of keys for the operator to make various settings and a display for displaying various information.

  The photosensitive drum 2030a, the charging device 2032a, the developing roller 2033a, and the cleaning unit 2031a are used as a set, and constitute an image forming station (hereinafter also referred to as “K station” for convenience) that forms a black image.

  The photosensitive drum 2030b, the charging device 2032b, the developing roller 2033b, and the cleaning unit 2031b are used as a set, and constitute an image forming station (hereinafter also referred to as “C station” for convenience) that forms a cyan image.

  The photosensitive drum 2030c, the charging device 2032c, the developing roller 2033c, and the cleaning unit 2031c are used as a set, and constitute an image forming station (hereinafter also referred to as “M station” for convenience) that forms a magenta image.

  The photosensitive drum 2030d, the charging device 2032d, the developing roller 2033d, and the cleaning unit 2031d are used as a set, and constitute an image forming station (hereinafter also referred to as “Y station” for convenience) that forms a yellow image.

  Each photosensitive drum has a photosensitive layer formed on the surface thereof. Each photosensitive drum is rotated in the direction of the arrow in the plane of FIG. 1 by a rotation mechanism (not shown).

  Each charging device uniformly charges the surface of the corresponding photosensitive drum.

  The optical scanning device 2010A scans the surfaces of the charged photosensitive drum 2030a and the photosensitive drum 2030b with light modulated for each color based on black image information and cyan image information from the printer control device 2090, respectively. To do. Thereby, a latent image corresponding to the image information is formed on the surface of each photosensitive drum. The latent image formed here moves in the direction of the corresponding developing roller as the photosensitive drum rotates.

  The optical scanning device 2010B scans the surfaces of the charged photosensitive drum 2030c and the photosensitive drum 2030d with light modulated for each color based on the magenta image information and the yellow image information from the printer control device 2090, respectively. To do. Thereby, a latent image corresponding to the image information is formed on the surface of each photosensitive drum. The latent image formed here moves in the direction of the corresponding developing roller as the photosensitive drum rotates.

  Here, the surface of each photosensitive drum is a surface to be scanned. Each photosensitive drum is an image carrier. Each optical scanning device will be described later.

  By the way, the scanning area in which the image information is written on each photosensitive drum is referred to as “effective scanning area”, “image forming area”, “effective image area”, and the like.

  As each developing roller rotates, toner from a corresponding toner cartridge (not shown) is thinly and uniformly applied to the surface thereof. Then, when the toner on the surface of each developing roller comes into contact with the surface of the corresponding photosensitive drum, the toner moves only to a portion irradiated with light on the surface and adheres to the surface. In other words, each developing roller causes toner to adhere to the latent image formed on the surface of the corresponding photosensitive drum so as to be visualized. Here, the toner-attached image (toner image) moves in the direction of the transfer belt 2040 as the photosensitive drum rotates.

  The yellow, magenta, cyan, and black toner images are sequentially transferred onto the transfer belt 2040 at a predetermined timing, and are superimposed to form a color image.

  Recording paper is stored in the paper feed tray 2060. A paper feed roller 2054 is disposed in the vicinity of the paper feed tray 2060. The paper feed roller 2054 takes out the recording paper one by one from the paper feed tray 2060. The recording paper is sent out toward the gap between the transfer belt 2040 and the transfer roller 2042 at a predetermined timing. As a result, the color image on the transfer belt 2040 is transferred to the recording paper. The recording paper on which the color image is transferred is sent to the fixing roller 2050.

  In the fixing roller 2050, heat and pressure are applied to the recording paper, whereby the toner is fixed on the recording paper. The recording paper on which the toner is fixed is sent to the paper discharge tray 2070 via the paper discharge roller 2058 and is sequentially stacked on the paper discharge tray 2070.

  Each cleaning unit removes toner (residual toner) remaining on the surface of the corresponding photosensitive drum. The surface of the photosensitive drum from which the residual toner has been removed returns to the position facing the corresponding charging device again.

  Next, details of the optical scanning device 2010A will be described.

  As shown in FIG. 2 and FIG. 3 as an example, the optical scanning device 2010A includes two light sources (2200a, 2200b), two collimating lenses (2201a, 2201b), two aperture plates (2203a, 2203b), two Cylindrical lenses (2204a, 2204b), optical deflector 2104A, two scanning lenses (2105a, 2105b), two folding mirrors (2106a, 2106b), condenser lens 2112A, synchronization detection sensor 2115A, surface identification sensor 110A, The illustrated scanning control device A is included.

  The scanning control device A includes a CPU, a program described in a code readable by the CPU, a ROM storing various data used when executing the program, a RAM as a working memory, an analog signal An A / D converter for converting the signal into a digital signal.

  The optical deflector 2104A has a four-sided mirror as a rotating polygon mirror (hereinafter also referred to as “polygon mirror”), and each mirror surface is a deflection reflection surface. This polygon mirror is rotated at a constant speed around a rotation axis by a drive mechanism (not shown), and deflects incident light at a constant angular velocity. The time required for one rotation of the polygon mirror is called a “rotation period”. The drive mechanism has a sensor for detecting the rotation state of the polygon mirror, and the detection result of the sensor is notified to the scanning control device A. Each opening plate is a plate-like member having an opening.

  Here, in the XYZ three-dimensional orthogonal coordinate system, the direction along the longitudinal direction (rotation axis direction) of each photoconductor drum is described as the Y-axis direction, and the direction parallel to the rotation axis of the polygon mirror is described as the Z-axis direction.

  Each light source has a semiconductor laser and is turned on and off by the scanning control device A. For convenience, light emitted from the light source 2200a is also referred to as “light LBa”, and light emitted from the light source 2200b is also referred to as “light LBb”.

  Light LBa from the light source 2200a is made into substantially parallel light by the collimator lens 2201a and shaped by the aperture plate 2203a. The light LBa that has passed through the opening of the aperture plate 2203a is condensed in the vicinity of the deflection reflection surface of the optical deflector 2104A with respect to the Z-axis direction by the cylindrical lens 2204a. The light LBa deflected by the optical deflector 2104A is collected by the scanning lens 2105a and guided to the photosensitive drum 2030a by the folding mirror 2106a.

  The light LBb from the light source 2200b is made substantially parallel light by the collimator lens 2201b and shaped by the aperture plate 2203b. The light LBb that has passed through the opening of the aperture plate 2203b is collected in the vicinity of the deflection reflection surface of the optical deflector 2104A in the Z-axis direction by the cylindrical lens 2204b. The light LBb deflected by the optical deflector 2104A is collected by the scanning lens 2105b and guided to the photosensitive drum 2030b by the folding mirror 2106b.

  The light spot formed on the surface of each photosensitive drum moves along the longitudinal direction of the photosensitive drum as the polygon mirror rotates. The moving direction of the light spot at this time is the “main scanning direction”, and the rotation direction of the photosensitive drum is the “sub scanning direction”.

  The synchronization detection sensor 2115A is disposed at a position where light before the start of writing on the photosensitive drum 2030b is received via the condenser lens 2112A. The synchronization detection sensor 2115A outputs a synchronization detection signal to the scanning control device A.

  Here, in the synchronization detection sensor 2115A, the synchronization detection signal becomes “high level” when the amount of received light is smaller than a predetermined value, and the synchronization detection signal becomes “low level” when the amount of received light is equal to or greater than the predetermined value. It is comprised so that it may become. That is, when the synchronization detection sensor 2115A receives light, the synchronization detection signal changes from “high level” to “low level”.

  The scanning control apparatus A obtains the writing start timing on the photosensitive drum 2030a and the photosensitive drum 2030b based on the output signal (synchronization detection signal) of the synchronization detection sensor 2115A.

  As shown in FIG. 4 as an example, the scanning control device A detects the rising of the output signal of the synchronization detection sensor 2115A from “low level” to “high level”, and then passes to the photosensitive drum 2030b after the elapse of time Tk. Start writing. The time Tk is the time from the rise timing of the synchronization detection signal to the write start timing, and is obtained in advance for each device and stored in the memory of the scanning control device A.

  In this embodiment, since a synchronization detection sensor corresponding to the photosensitive drum 2030a is not provided, a synchronization detection signal for the photosensitive drum 2030a cannot be obtained.

  In this case, as shown in FIG. 5 as an example, the scanning control apparatus A generates a pseudo synchronization signal synchronized with the output signal of the synchronization detection sensor 2115A, instead of the synchronization detection signal for the photosensitive drum 2030a. Then, writing to the photosensitive drum 2030a is started after the elapse of time Tk from the rising timing of the pseudo synchronization signal.

  Here, the four deflection reflection surfaces of the polygon mirror are defined as “surface 1”, “surface 2”, “surface 3”, and “surface 4” counterclockwise (see FIG. 6). A linear mark M extending from the center of the surface to the corner between the surface 1 and the surface 4 is added to the surface on the + Z side of the polygon mirror (see FIG. 6). When there is no need to specify the deflecting / reflecting surface, the mark M may be omitted.

  As shown in FIG. 7 as an example, the surface specifying sensor 110A is arranged on the + Z side of the optical deflector 2104A, and irradiates light on the surface on the + Z side of the polygon mirror, and the light reflected by the surface. It has a photodetector for receiving light. When detecting the mark M, the surface specifying sensor 110A outputs a surface specifying signal that changes from “high level” to “low level” to the scanning control device A (see FIG. 8).

  Therefore, as shown in FIG. 9 as an example, the scanning control apparatus A is based on a surface specifying signal from the surface specifying sensor 110A, and a deflection reflection surface that reflects the light when the synchronization detection sensor 2115A receives the light. Can be specified as one of surface 1, surface 2, surface 3, and surface 4.

  By the way, the polygon mirror has a variation in distance A (see FIG. 10) from the center of rotation to each deflection reflection surface (hereinafter also referred to as “A dimension variation” for convenience) and two deflection reflection surfaces adjacent to each other. There is variation in angle θ (see FIG. 11) (hereinafter, also referred to as “inter-surface angle variation” for convenience). In addition, the polygon mirror causes rotation unevenness during rotation.

  Therefore, the timing interval at which the synchronization detection sensor 2115A receives light is not constant and varies. The scanning control apparatus A generates the pseudo synchronization signal in consideration of the variation.

  By the way, the rotation unevenness includes an uneven component having the same cycle as the rotation cycle of the polygon mirror and an uneven component having a cycle shorter than the rotation cycle of the polygon mirror. The unevenness component having the same period as the rotation period of the polygon mirror can be corrected by the scanning control apparatus A by adjusting the pulse width of the pixel clock signal, for example. On the other hand, it is difficult for the scanning control apparatus A to correct the uneven component having a cycle shorter than the rotation cycle of the polygon mirror.

  If the non-uniform component having a period shorter than the rotation period of the polygon mirror is large, the accuracy of the pseudo synchronization signal is lowered, and the write start timing to the photosensitive drum 2030a is deviated from a desired timing. As a result, the output image Color misalignment occurs.

  Therefore, in the present embodiment, the presence or absence of abnormality of the optical deflector 2104A is determined using an uneven component having a period shorter than the rotation period of the polygon mirror.

  Here, an abnormality inspection process of the optical deflector 2104A performed by the scanning control apparatus A will be described. The flowcharts of FIGS. 12 and 13 correspond to a series of processing algorithms executed by the CPU of the scanning control apparatus A during the abnormality inspection process.

  This abnormality inspection process includes (1) adjustment in the manufacturing process of the color printer 2000, (2) before shipment of the color printer 2000, (3) when there is a print request, and (4) the cumulative usage time of the optical deflector 2104A. Is performed when a predetermined time (for example, about 10 hours) has elapsed since the previous abnormality inspection process, or (5) during maintenance.

  In the first step S401, the light source 2200b is turned on. If the light source 2200b is already turned on, this step is skipped.

  In the next step S403, the polygon mirror is rotationally driven through the drive mechanism. If the polygon mirror has already been rotated, this step is skipped.

  In the next step S405, it is determined whether or not the rotation of the polygon mirror is stable based on the output of the drive mechanism. If the rotation of the polygon mirror is not stable, the determination here is denied and the process proceeds to step S407.

  In step S407, after waiting for a preset time, the process returns to step S405.

  If the rotation of the polygon mirror is stable, the determination in step S405 is affirmed and the process proceeds to step S409.

  In the next step S409, the surface specification signal and the synchronization detection signal are acquired by using the time required for the polygon mirror to rotate about 1000 times as the measurement time.

  In the next step S411, the light source 2200b is turned off. Note that this step is skipped when the light source 2200b needs to be turned on, for example, when there is a print request.

  In the next step S413, the rotational drive of the polygon mirror is stopped via the drive mechanism. Note that this step is skipped when the polygon mirror needs to be driven to rotate, for example, when there is a print request.

  In the next step S415, the time interval of the light reception timing at the synchronization detection sensor 2115A of the light reflected by each deflection reflection surface is obtained from the acquisition result of the surface specifying signal and the synchronization detection signal. Here, the time interval between the light reception timing of the light reflected by the surface 1 and the light reception timing of the light reflected by the surface 2 is d12 (t), and the light reception timing of the light reflected by the surface 2 and the reflection by the surface 3 The time interval between the light reception timing of the reflected light and the light reception timing of the light reflected from the surface 3 and the light reception timing of the light reflected from the surface 4 is d34 (t). A time interval between the light reception timing of the light reflected by 4 and the light reception timing of the light reflected by the surface 1 is d41 (t) (see FIG. 14).

  In the next step S417, an average value Av1 of all obtained time intervals is calculated.

  In the next step S419, the difference from the average value Av1 is calculated for all time intervals. This will be referred to as “first variation”. Here, the difference between the time interval d12 (t) and the average value Av1 is Δd12 (t), the difference between the time interval d23 (t) and the average value Av1 is Δd23 (t), and the time interval d34 (t) is The difference from the average value Av1 is Δd34 (t), and the difference between the time interval d41 (t) and the average value Av1 is Δd41 (t). An example of the obtained first variation is shown in FIGS. 15 and 16. FIG. 16 is an enlarged view of a part of FIG.

  In the next step S421, a time required for one rotation of the polygon mirror (hereinafter also referred to as “one rotation time” for convenience) is obtained from the acquisition result of the surface specifying signal and the synchronization detection signal. Here, as shown in FIG. 17 as an example, the time interval d11 (t) between the timing at which the light reflected by the surface 1 is received and the timing at which the light reflected at the surface 1 is received next as one rotation time. ), The time interval d22 (t) between the timing of receiving the light reflected on the surface 2 and the timing of receiving the light reflected on the surface 2 next, the timing of receiving the light reflected on the surface 3 and the next The time interval d33 (t) with the timing of receiving the light reflected by the surface 3, the time interval d44 between the timing of receiving the light reflected by the surface 4 and the timing of receiving the light reflected by the surface 4 next. (T) is obtained sequentially.

  In the next step S423, the obtained average value Av2 of one rotation time is calculated.

  In the next step S501, the difference from the average value Av2 is calculated for all one rotation time. Here, the difference between the one rotation time d11 (t) and the average value Av2 is Δd11 (t), the difference between the one rotation time d22 (t) and the average value Av2 is Δd22 (t), and the one rotation time d33 ( The difference between t) and the average value Av2 is Δd33 (t), and the difference between one rotation time d44 (t) and the average value Av2 is Δd44 (t). This is the rotation unevenness obtained from the actual measurement value of the time required for one rotation of the polygon mirror.

  In the next step S503, the rotation unevenness Δd11 (t), Δd22 (t), Δd33 (t), and Δd44 (t) obtained in step S501 are converted to 1/4 rotation unevenness. (See FIG. 18). This rotation unevenness will be referred to as “first rotation unevenness”. An example of this first rotation unevenness is shown in FIGS. FIG. 20 is an enlarged view of a part of FIG.

  In the next step S505, the difference between the first variation and the first rotation unevenness is calculated. This is called “second variation”. This second variation is a variation caused by the A dimension variation and the inter-surface angle variation. An example of the second variation is shown in FIGS. 21 and 22. Note that FIG. 22 is an enlarged view of a part of FIG.

  In the next step S507, the calculated second variation is separated for each of the two deflection reflecting surfaces adjacent to each other. Here, the second variation (see FIG. 23) regarding the relationship between the surface 1 and the surface 2 calculated by Δd12 (t) −Δd11 (t) / 4, and Δd23 (t) −Δd22 (t) / 4 Second variation regarding the relationship between the calculated surface 2 and the surface 3 (see FIG. 24) and the second relationship regarding the relationship between the surface 3 and the surface 4 calculated by Δd34 (t) −Δd33 (t) / 4. The variation (see FIG. 25) is separated from the second variation (see FIG. 26) regarding the relationship between the surface 4 and the surface 1 calculated by Δd41 (t) −Δd44 (t) / 4.

  In the next step S509, an average value is obtained for each separated second variation. Here, the average value of the second variation regarding the relationship between the surface 1 and the surface 2 is Av12, the average value of the second variation regarding the relationship between the surface 2 and the surface 3 is Av23, and the surface 3 and the surface 4 An average value of the second variation regarding the relationship is Av34, and an average value of the second variation regarding the relationship between the surface 4 and the surface 1 is Av41.

  In the next step S511, a difference between the first variation and each average value of the separated second variation is calculated. Here, Δd12 (t) −Av12, Δd23 (t) −Av23, Δd34 (t) −Av34, and Δd41 (t) −Av41 are calculated. The result obtained here will be referred to as “second rotation unevenness”. An example of this second rotation unevenness is shown in FIG.

  In the next step S513, the difference between the second rotation unevenness and the first rotation unevenness (see FIG. 28) is calculated. The result obtained here will be referred to as “third rotation unevenness”. The third rotation unevenness is an uneven component having a cycle shorter than the rotation cycle of the polygon mirror included in the first rotation unevenness. An example of this third rotation unevenness is shown in FIG.

  In the next step S515, the standard deviation σ of the third rotation unevenness is calculated.

  In the next step S517, it is checked whether or not the value of 3σ exceeds 10 nsec. If the value of 3σ exceeds 10 nsec, the determination here is affirmed and the process proceeds to step S519. This 10 nsec is the lighting time of the light source corresponding to one dot.

  In this step S519, it is determined that there is an abnormality in the optical deflector 2104A. Then, control goes to a step S523.

  On the other hand, if the value of 3σ does not exceed 10 nsec in step S517, the determination in step S517 is denied and the process proceeds to step S521.

  In this step S521, it is determined that there is no abnormality in the optical deflector 2104A. Then, control goes to a step S523.

  In step S523, the printer controller 2090 is notified of the determination result. The printer control device 2090 displays the determination result on the display of the operation panel. For example, when the determination result is abnormal, a value of 3σ or the like is displayed together with a message that “the optical deflector 2104A is abnormal”. In this case, the worker notifies the maintenance company of the display content of the display. When the determination result is normal, a value of 3σ or the like is displayed together with a message that “the optical deflector 2104A is normal”.

  The determination result may be automatically notified from the color printer 2000 to a maintenance company or the like via a public line or the Internet (see, for example, JP 2012-63383 A). Then, the abnormality inspection process ends.

  Next, the optical scanning device 2010B will be described.

  As shown in FIG. 30 and FIG. 31 as an example, the optical scanning device 2010B includes two light sources (2200c, 2200d), two collimating lenses (2201c, 2201d), two aperture plates (2203c, 2203d), two Cylindrical lens (2204c, 2204d), optical deflector 2104B, two scanning lenses (2105c, 2105d), two folding mirrors (2106c, 2106d), condenser lens 2112B, synchronization detection sensor 2115B, surface specifying sensor 110B, The illustrated scanning control device B is included.

  The optical scanning device 2010B has the same configuration as the optical scanning device 2010A described above, and detailed description of each optical member is omitted.

  Then, in the same manner as the scanning control device A, the scanning control device B performs an abnormality inspection process for the optical deflector 2104B.

  As is clear from the above description, in the optical scanning device A according to the present embodiment, the light receiving device of the present invention is configured by the synchronization detection sensor 2115A, and the processing device of the present invention is configured by the scanning control device A. Further, in the optical scanning device B according to the present embodiment, the photodetector of the present invention is configured by the synchronization detection sensor 2115B, and the processing device of the present invention is configured by the scanning control device B.

  As described above, each optical scanning device according to the present embodiment includes two light sources, two coupling lenses, two aperture plates, two cylindrical lenses, an optical deflector, two scanning lenses, and two folding mirrors. , A condensing lens, a synchronization detection sensor, and a scanning control device.

  The scanning control device obtains the first variation and the first rotation unevenness based on the output of the synchronization detection sensor, and calculates the second variation from the difference therebetween. Next, the scanning control device obtains the second rotation unevenness from the first variation and the second variation, and from the difference between the second rotation unevenness and the first rotation unevenness, from the rotation cycle of the polygon mirror. 3rd rotation unevenness which is the rotation unevenness of a short period is also calculated. Then, when the value of 3σ of the third rotation unevenness exceeds the lighting time of the light source corresponding to one dot, the scanning control device determines that there is an abnormality in the optical deflector.

  Therefore, according to each optical scanning device, it is possible to accurately know the abnormality of the optical deflector.

  Since the color printer 2000 includes the optical scanning device 2010A and the optical scanning device 2010B, maintenance of the optical deflector can be performed appropriately. As a result, a high quality image can be stably formed.

In the above embodiment, the case where the presence / absence of abnormality of the optical deflector is determined based on whether or not the 3σ value of the third rotation unevenness exceeds the lighting time of the light source corresponding to 1 dot has been described. It is not limited to this. For example, the presence / absence of an abnormality may be determined based on third rotation unevenness obtained at a plurality of times when the cumulative usage time of the optical deflector is different from each other. For example, the standard deviation σ ₁ of the third rotation unevenness obtained when the color printer 2000 is new is compared with the standard deviation σ ₂ of the third rotation unevenness obtained at the time of printing. For example, σ ₂ > 2 When xσ ₁ , it may be determined that “the optical deflector is abnormal”.

  Further, the occurrence timing of the abnormality may be predicted based on the third rotation unevenness obtained at a plurality of times when the accumulated usage time of the optical deflector is different from each other.

  In the above embodiment, the measurement time of the surface identification signal and the synchronization detection signal in the abnormality inspection process has been described as the time required for the polygon mirror to rotate about 1000 times. However, the present invention is not limited to this. Absent.

  In the above-described embodiment, the case where the scanning control device of each optical scanning device performs the abnormality inspection process of the optical deflector has been described. However, the present invention is not limited to this, and the determination to perform the abnormality inspection process of the optical deflector is performed. The apparatus may be provided separately from the scanning control apparatus (see FIG. 32). In this case, the printer control device 2090 may have the function of a determination device.

  Further, a determination device connected to the color printer 2000 via a network such as a LAN, a public line, and the Internet may be provided to remotely monitor the color printer 2000 (see FIG. 33). In this case, the surface identification signal and the synchronization detection signal are sent from the color printer 2000 to the determination device via the network, and the abnormality inspection process is performed by the determination device. When the determination device determines that there is an abnormality in the optical deflector, the service person visits the user of the color printer 2000 with the replacement optical deflector.

  In this case, the determination device may be incorporated in the LAN (local network) of the maintenance company, or may be incorporated in the LAN of the manufacturer's factory or support center.

  Further, the color printer 2000 may be provided with a terminal or a port for outputting the surface specifying signal and the synchronization detection signal to the outside. In this case, even if the abnormality inspection process cannot be performed on the color printer 2000 side, the above-described abnormality inspection is performed at the time of maintenance by adding the function of the determination device to the measuring apparatus brought by the service person at the time of maintenance. Processing can be performed. Further, by adding the function of the determination device to the inspection device used in the manufacturer's factory, the abnormality inspection process can be performed in the manufacturing process.

  Moreover, in the said embodiment, you may use the surface emitting laser array which has a some light emission part as a semiconductor laser in each light source.

  In the above-described embodiment, the case where the number of light sources in the optical scanning device 2010A is two has been described. However, the present invention is not limited to this, and the number of light sources is one as shown in FIG. 34 as an example. There may be.

  In this case, a half mirror prism 2205 is disposed on the optical path of light that has passed through the opening of the opening plate 2203a. The half mirror prism 2205 has a beam splitting surface with the same transmittance and reflectance with respect to incident light.

  Therefore, the light that has passed through the opening of the aperture plate 2203a is divided by the half mirror prism 2205 with the same light intensity as the reflected light and the transmitted light. The light reflected by the half mirror prism 2205 enters the optical deflector 2104A via the cylindrical lens 2204a and the reflection mirror M1. The light transmitted through the half mirror prism 2205 is incident on the optical deflector 2104A through the cylindrical lens 2204b and the reflection mirror M2.

  Similarly, the number of light sources in the optical scanning device 2010B may be one.

  In the above-described embodiment, the case where the surface specifying sensor is provided in each optical scanning device has been described. However, the present invention is not limited to this, and at least one of the optical scanning device 2010A and the optical scanning device 2010B is a surface. The specific sensor may not be provided.

  For example, when the surface specifying sensor 2115A is not provided in the optical scanning device 2010A, the scanning control device A is required for the polygon mirror to rotate about 1000 in step S409 in the abnormality inspection process of the optical deflector 2104A. The synchronization detection signal is acquired using the time as the measurement time. In step S415, the first light reception timing in the synchronization detection signal is the light reception timing of the light reflected by the surface 1, the next light reception timing is the light reception timing of the light reflected by the surface 2, and the next light reception timing. Is the light reception timing of the light reflected on the surface 3, and the next light reception timing is the light reception timing of the light reflected on the surface 4. From the result of acquisition of the synchronization detection signal, the light reflected on each deflection reflection surface The time interval of the light reception timing in the synchronization detection sensor 2115A is obtained.

  The determination as to whether or not there is an abnormality in the optical deflector 2104A (step S517 above) is made using the value of the standard deviation σ of the third rotation unevenness calculated in step S515. If any non-uniform component having a period shorter than the rotation period of the polygon mirror is the same for any deflection reflection surface of the polygon mirror as the measurement start surface, the same value can be obtained as the standard deviation σ. For example, if the measurement start plane is different between the first (for example, initial) abnormality inspection process and the second (for example, printing) abnormality inspection process, the relationship between the time interval of the synchronization detection signal in step S415 and the surface number However, since the calculated standard deviation σ of the third rotation unevenness is not related to the surface number, the first and second times of the optical deflector 2104A are different from each other. It is possible to correctly determine whether there is an abnormality.

  The same applies when the surface specifying sensor 2115B is not provided in the optical scanning device 2010B.

  In the above embodiment, the optical scanning device 2010A and the optical scanning device 2010B may be integrated.

  In the above embodiment, the optical scanning device 2010 shown in FIGS. 35 and 36 may be used instead of the optical scanning device 2010A and the optical scanning device 2010B. Hereinafter, the optical scanning device 2010 will be briefly described.

  The optical scanning device 2010 includes two light sources (2200A, 2200B), two collimating lenses (2201A, 2201B), two aperture plates (2203A, 2203B), a half mirror prism 2205, two cylindrical lenses (2204A, 2204B), Two reflecting mirrors (M1, M2), an optical deflector 2104, a scanning optical system A, a scanning optical system B, a condensing lens 2112, a synchronization detection sensor 2115, a surface specifying sensor (not shown), a scanning control device (not shown), and the like. Have.

  The scanning optical system A has a scanning lens 2105A, a polarization separation element 2110A, and three folding mirrors (2106a, 2106b, 2108b). The scanning optical system B includes a scanning lens 2105B, a polarization separation element 2110B, and three folding mirrors (2106c, 2106d, 2108c).

  The light source 2200A is installed such that linearly polarized light whose polarization direction (vibration plane of the electric field vector) is parallel to the Z-axis direction is emitted. The light source 2200B is installed such that linearly polarized light whose polarization direction is orthogonal to the Z-axis direction is emitted.

  Light emitted from the light source 2200A and passing through the collimator lens 2201A and the aperture plate 2203A is split into reflected light (also referred to as “light LBa”) and transmitted light (also referred to as “light LBd”) by the half mirror prism 2205. . Light emitted from the light source 2200B and passing through the collimator lens 2201B and the aperture plate 2203B is split into reflected light (also referred to as “light LBc”) and transmitted light (also referred to as “light LBb”) by the half mirror prism 2205. .

  The light LBa and the light LBb are incident on the optical deflector 2104 via the cylindrical lens 2204A and the reflection mirror M1. The light LBc and the light LBd are incident on the optical deflector 2104 via the cylindrical lens 2204B and the reflection mirror M2.

  The light LBa and the light LBb deflected by the optical deflector 2104 enter the polarization separation element 2110A via the scanning lens 2105A. The light LBa passes through the polarization separation element 2110A and is guided to the photosensitive drum 2030a through the folding mirror 2106a and the exit window 2111a. The light LBb is reflected by the polarization separation element 2110A and guided to the photosensitive drum 2030b through the folding mirror 2106b, the folding mirror 2108b, and the exit window 2111b.

  The light LBc and the light LBd deflected by the optical deflector 2104 enter the polarization separation element 2110B via the scanning lens 2105B. The light beam LBc is reflected by the polarization separation element 2110B and guided to the photosensitive drum 2030c through the folding mirror 2106c, the folding mirror 2108c, and the exit window 2111c. The light LBd passes through the polarization separation element 2110B, and is guided to the photosensitive drum 2030d through the folding mirror 2106d and the exit window 2111d.

  The scanning control device performs an abnormality inspection process for the optical deflector 2104 based on the outputs of the surface identification sensor and the synchronization detection sensor 2115 in the same manner as the abnormality inspection process described above.

  Moreover, although the said embodiment demonstrated the case where a polygon mirror had four deflection | deviation reflective surfaces, it is not limited to this. For example, the polygon mirror may have six deflecting reflecting surfaces.

  In the above embodiment, a color printer having four photosensitive drums has been described as the image forming apparatus. However, the present invention is not limited to this. For example, a printer having two photosensitive drums may be used. In this case, the optical scanning device 2010A or the optical scanning device 2010B can be used. Further, a color printer using auxiliary colors may be used.

  In the above embodiment, the image forming apparatus in which the toner image is transferred from the photosensitive drum to the recording paper via the intermediate transfer belt has been described. However, the present invention is not limited to this, and the toner image is transferred from the photosensitive drum. An image forming apparatus that is directly transferred to a recording sheet may be used.

  Further, the image forming apparatus may be an image forming apparatus using a color developing medium (positive photographic paper) that develops color by the thermal energy of the light spot as the image carrier. In this case, a visible image can be directly formed on the image carrier by optical scanning.

  In the above-described embodiment, the case of a color printer has been described as the image forming apparatus. However, the present invention is not limited to this, and an image forming apparatus other than a printer, for example, a copier, a facsimile, or a multifunction machine in which these are integrated. There may be.

  110A ... Surface identification sensor, 110B ... Surface identification sensor, 2000 ... Color printer (image forming device), 2010 ... Optical scanning device, 2010A ... Optical scanning device, 2010B ... Optical scanning device, 2030a-2030d ... Photosensitive drum (image carrier) Body), 2104... Optical deflector, 2104A... Optical deflector, 2104B. ˜2201d ... collimating lens, 2203a-2203d ... aperture plate, 2204a-2204d ... cylindrical lens.

JP 2001-175328 A JP 2007-328645 A

Claims (11)

In an optical scanning device that scans a surface to be scanned with light emitted from a light source and reflected by a rotary polygon mirror of an optical deflector,
A light receiver for receiving the light reflected by each mirror surface of the rotary polygon mirror;
A processing device for determining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on an output of the light receiver, and determining whether there is an abnormality of the optical deflector ,
The processing device obtains a first variation that is a variation in time interval of the light reception timing, obtains a first rotation unevenness from a time required for one rotation of the rotary polygon mirror, and determines the first variation from the first variation. The second variation in which the rotation unevenness is removed is obtained, and the second rotation unevenness including a rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror is obtained from the first variation and the second variation. Optical scanning device to be sought . 2. The light according to claim 1 , wherein the processing device obtains a rotation unevenness having a period shorter than a rotation period of the rotary polygon mirror from a difference between the second rotation unevenness and the first rotation unevenness. Scanning device. In an optical scanning device that scans a surface to be scanned with light emitted from a light source and reflected by a rotary polygon mirror of an optical deflector,
A light receiver for receiving the light reflected by each mirror surface of the rotary polygon mirror;
A processing device for determining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on an output of the light receiver, and determining whether there is an abnormality of the optical deflector ,
The processing device is an optical scanning device that determines the presence or absence of abnormality from rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror obtained at a plurality of times when the cumulative usage time of the optical deflector is different from each other . The processing unit, if beyond the lighting time uneven rotation of a period shorter than the rotation period of the rotating polygon mirror corresponds to one dot, any of the preceding claims, characterized in that it is determined that the abnormality An optical scanning device according to claim 1. An image carrier;
Image forming apparatus and an optical scanning device according to any one of claims 1 to 4, scanned by the light of the image bearing member. An image carrier;
A light source;
An optical deflector having a rotating polygon mirror and reflecting the light emitted from the light source by the rotating polygon mirror;
An optical system for guiding the light reflected by the rotary polygon mirror to the image carrier;
A light receiver for receiving the light reflected by each mirror surface of the rotary polygon mirror;
A processing device for determining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on an output of the light receiver, and determining whether there is an abnormality of the optical deflector ,
The processing device obtains a first variation that is a variation in time interval of the light reception timing, obtains a first rotation unevenness from a time required for one rotation of the rotary polygon mirror, and determines the first variation from the first variation. The second variation in which the rotation unevenness is removed is obtained, and the second rotation unevenness including a rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror is obtained from the first variation and the second variation. Image forming apparatus to be sought . An image carrier;
A light source;
An optical deflector having a rotating polygon mirror and reflecting the light emitted from the light source by the rotating polygon mirror;
An optical system for guiding the light reflected by the rotary polygon mirror to the image carrier;
A light receiver for receiving the light reflected by each mirror surface of the rotary polygon mirror;
A processing device for determining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on an output of the light receiver, and determining whether there is an abnormality of the optical deflector ,
The processing device is an optical scanning device that determines presence / absence of abnormality from rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror obtained at a plurality of times when the cumulative usage time of the optical deflector is different from each other. . In a system including a light source, an optical deflector having a rotary polygon mirror, and a light receiver that receives light reflected by each mirror surface of the rotary polygon mirror,
A determination device for determining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on an output of the light receiver, and determining whether the optical deflector is abnormal ;
The determination device obtains a first variation which is a variation in time interval of the light reception timing, obtains a first rotation unevenness from a time required for one rotation of the rotary polygon mirror, and determines the first variation from the first variation. The second variation in which the rotation unevenness is removed is obtained, and the second rotation unevenness including a rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror is obtained from the first variation and the second variation. The system you want . In a system including a light source, an optical deflector having a rotary polygon mirror, and a light receiver that receives light reflected by each mirror surface of the rotary polygon mirror,
A determination device for determining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on an output of the light receiver, and determining whether the optical deflector is abnormal ;
The determination device is a system for determining whether or not there is an abnormality from rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror obtained at a plurality of times when the accumulated usage time of the optical deflector is different from each other . A system management method comprising a light source, an optical deflector having a rotating polygon mirror, and a light receiver that receives light reflected by each mirror surface of the rotating polygon mirror,
Obtaining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on the output of the light receiver ;
A first variation which is a variation in time interval of the light receiving timing is obtained, a first rotation unevenness is obtained from a time required for one rotation of the rotary polygon mirror, and the first rotation unevenness is removed from the first variation. The obtained second variation is obtained, and from the first variation and the second variation, a second rotation unevenness including a rotation unevenness having a cycle shorter than the rotation cycle of the rotary polygon mirror is obtained, and the first variation is obtained. management method from uneven rotation and the second rotation unevenness and a step of determining the presence or absence of an abnormality of the optical deflector. A system management method comprising a light source, an optical deflector having a rotating polygon mirror, and a light receiver that receives light reflected by each mirror surface of the rotating polygon mirror,
Obtaining a time interval of light reception timing at the light receiver of the light reflected by each mirror surface based on the output of the light receiver ;
Management, including the steps of determining the presence or absence of an abnormality of the optical deflector from the rotation unevenness of a period shorter than the rotation period of the rotary polygon mirror obtained to different times the cumulative usage time from each other of the optical deflector Method.

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