Image forming apparatus

Abstract

To provide an image forming apparatus that can reduce the execution time of preparatory operation.SOLUTION: An image forming apparatus 100 comprises an image forming unit 10 and a control unit 20. The image forming unit 10 forms an image on a sheet. The control unit 20 controls the image forming unit 10. The image forming unit 10 includes a photoreceptor drum, an exposure unit 13 that forms an electrostatic latent image corresponding to the image on the photoreceptor drum, a developing unit that develops the electrostatic latent image with toner, and a cleaning unit 13a that cleans the exposure unit 13. The control unit 20 cleans the exposure unit 13 with a cleaning unit 13a, and performs aging of the photoreceptor drum at the same time.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] In order to prevent image deletion, a technique is known in which an aging operation is performed on the photosensitive drum before image formation. The aging operation is an operation for polishing and removing discharge products that have accumulated on the surface of the photosensitive drum. In the image forming device described in Patent Document 1, the time for performing the aging operation is changed according to the degree of image deletion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-32758 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an image forming apparatus, when a preparatory operation including an aging operation is performed, an exposure unit that forms an electrostatic latent image on a photoconductor drum may be cleaned. In the image forming apparatus described in Patent Document 1, the aging operation is performed after cleaning the exposure unit, so the preparatory operation takes a long time to perform.

[0005] SUMMARY OF THE PRESENT DISCLOSURE The present invention has been made in consideration of the above-mentioned problems, and has an object to provide an image forming apparatus capable of shortening the time required for executing a warm-up operation. [Means for solving the problem]

[0006] According to one aspect of the present invention, an image forming apparatus includes an image forming unit and a control unit. The image forming unit forms an image on a sheet. The control unit controls the image forming unit. The image forming unit includes a photosensitive drum, an exposure unit that forms an electrostatic latent image corresponding to the image on the photosensitive drum, a development unit that develops the electrostatic latent image with toner, and a cleaning unit that cleans the exposure unit. The control unit cleans the exposure unit with the cleaning unit and simultaneously cleans the photosensitive drum with the photosensitive drum cleaning unit. Effect of the Invention

[0007] According to the image forming apparatus of the present invention, the time required for performing the warm-up operation can be reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional view illustrating an example of a configuration of an image forming unit according to the present embodiment. [Diagram 3] 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention; [Figure 4] 6 is a flowchart illustrating an example of a process of a control unit according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference characters and the description will not be repeated. In the embodiment, the X-axis and the Y-axis are horizontal, the Z-axis is vertical, and the X-axis, the Y-axis, and the Z-axis are mutually orthogonal.

[0010] First, the configuration of an image forming apparatus 100 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing the configuration of the image forming apparatus 100. The image forming apparatus 100 is, for example, a color multifunction peripheral.

[0011] As shown in FIG. 1, the image forming apparatus 100 includes an image forming unit 10, a feeding section 30, a conveying section 40, a fixing section 50, a discharge section 60, a control section 20, a memory section 80, an operation section 120, a document feeding section 90, a scanner section 91 and a power supply section 104.

[0012] When the power supply unit 104 is turned on, it supplies power to the image forming apparatus 100. On the other hand, when the power supply unit 104 is turned off, it stops supplying power to the image forming apparatus 100.

[0013] The document feeder 90 includes a document placement unit 90a. The document feeder 90 transports the document G set on the document placement unit 90a to a reading position of the scanner unit 91.

[0014] The scanner unit 91 illuminates the document G with an exposure lamp and receives the reflected light with a CCD (Charge Coupled Device), thereby reading an image from the document G and generating image data representing the image. The image data includes, for example, a plurality of pixel data each of which indicates a plurality of gradation values. The scanner unit 91 then outputs the image data to the control unit 20.

[0015] The feeding section 30 supplies the sheet P to the conveying section 40. The conveying section 40 conveys the sheet P to the discharge section 60 via the image forming unit 10 and the fixing section 50. The sheet P is, for example, plain paper, copy paper, recycled paper, thin paper, thick paper, glossy paper, or OHP (Overhead Projector).

[0016] The image forming unit 10 forms an image on a sheet P based on image data. The fixing section 50 heats and pressurizes the sheet P, and fixes the toner image transferred to the sheet P to the sheet P. The discharge section 60 discharges the sheet P to the outside of the image forming apparatus 100.

[0017] The control unit 20 controls the image forming unit 10, the feeding unit 30, the transport unit 40, the fixing unit 50, the discharge unit 60, the document feeding unit 90, and the scanner unit 91. Specifically, the control unit 20 includes a processor such as a CPU (Central Processing Unit).

[0018] The storage unit 80 includes a storage device and stores a computer program. Specifically, the storage unit 80 includes a main storage device such as a semiconductor memory, and an auxiliary storage device such as a semiconductor memory and / or a hard disk drive.

[0019] The operation unit 120 includes a display unit and an operation key unit. The display unit is, for example, a liquid crystal display. The display unit displays image information. The display unit also functions as a touch panel for input.

[0020] Next, a description will be given of the configuration of the image forming unit 10. The image forming unit 10 includes a plurality of image forming sections 11, an exposure section 13, and a transfer section 12. That is, there are a plurality of image forming sections 11.

[0021] The multiple image forming units 11 are each supplied with toner of multiple colors different from one another. The toner includes a large number of toner particles. Each of the multiple image forming units 11 includes a photoconductor drum 101. For example, the multiple image forming units 11 include an image forming unit 11c to which cyan toner is supplied, an image forming unit 11m to which magenta toner is supplied, an image forming unit 11y to which yellow toner is supplied, and an image forming unit 11k to which black toner is supplied. The image forming units 11c, 11m, 11y, and 11k are substantially identical in configuration to one another.

[0022] The exposure unit 13 has, for example, a light source, a polygon mirror, a reflecting mirror, and a deflecting mirror. The exposure unit 13 irradiates each of the multiple photoconductor drums 101 with laser light. As a result, an electrostatic latent image is formed on each of the multiple photoconductor drums 101. Then, the multiple image forming units 11 each develop the multiple electrostatic latent images. The multiple electrostatic latent images are each developed with toner of multiple different colors. As a result, toner images of multiple different colors are formed on each of the multiple photoconductor drums 101.

[0023] The exposure unit 13 has a cleaning unit 13a. The cleaning unit 13a cleans the exposure unit 13. The cleaning unit 13a cleans, for example, the light source, the polygon mirror, the reflecting mirror, and the deflection mirror. Specifically, the cleaning unit 13a is driven based on a signal from the control unit 20. More specifically, the cleaning unit 13a is driven for a first predetermined time based on the signal from the control unit 20.

[0024] The transfer unit 12 includes an intermediate transfer belt 12a, a driving roller 12b, and a driven roller 12c. The intermediate transfer belt 12a is stretched around the driving roller 12b and the driven roller 12c. The intermediate transfer belt 12a is driven to rotate in a rotation direction RA by the driving roller 12b. A plurality of image forming units 11 transfer toner images of different colors onto the intermediate transfer belt 12a. The toner images of the different colors are superimposed on the intermediate transfer belt 12a, forming a toner image (specifically, a color image) on the intermediate transfer belt 12a. The transfer unit 12 transfers the toner image formed on the intermediate transfer belt 12a onto the sheet P.

[0025] Next, a configuration of the image forming unit 11 according to the embodiment will be described with reference to Fig. 2. Fig. 2 is a cross-sectional view showing an example of the configuration of the image forming unit 11.

[0026] 2, the image forming unit 11 further includes a photoconductor drum 101, a developing unit 110, a charging unit 102, a cleaning unit 103, and a toner container 116. The photoconductor drum 101 has a substantially cylindrical or cylindrical shape. The photoconductor drum 101 rotates in a rotation direction RB about a rotation axis AX of the photoconductor drum 101. The photoconductor drum 101 is, for example, an amorphous silicon (α-Si) photoconductor drum or an organic photoconductor (OPC: Organic PhotoConductor) drum.

[0027] The charging unit 102 charges the entire surface of the photoconductor drum 101 to a predetermined potential. The charging unit 102 includes, for example, a charging roller. As shown in FIG. 1, the exposure unit 13 exposes a predetermined area of ​​the surface of the photoconductor drum 101 to light. As a result, an electrostatic latent image is formed in the predetermined area of ​​the surface of the photoconductor drum 101.

[0028] Furthermore, the developing unit 110 develops the electrostatic latent image formed in a predetermined area on the surface of the photoconductor drum 101 by the plurality of toner particles to form a toner image in the predetermined area on the surface of the photoconductor drum 101. The plurality of toner particles are contained in a two-component developer.

[0029] Specifically, the two-component developer includes a plurality of carrier particles (specifically, a large number of carrier particles) in addition to a plurality of toner particles (specifically, a large number of toner particles). The plurality of toner particles is a powder, and the plurality of carrier particles is a powder. The toner particles are, for example, positively charged toner particles. The positively charged toner particles are positively charged by friction with the carrier particles.

[0030] The particle size of the toner particles is, for example, 5.0 μm or more and 8.0 μm or less, and preferably 5.2 μm or more and 6.7 μm or less, in terms of volume-based median diameter (D50).

[0031] The carrier particles are magnetic. The carrier particles are, for example, resin-coated carrier particles. The core particles of the resin-coated carrier particles are, for example, ferrite or magnetite. The particle size of the carrier particles is, for example, 20 μm or more and 100 μm or less, preferably 25 μm or more and 80 μm or less, in terms of volume average particle size.

[0032] Here, a development nip is formed between the development roller 112 and the photoconductor drum 101. When a development bias is applied to the development roller 112, an electric field is formed in the development nip. Therefore, the toner particles move from the development unit 110 to the photoconductor drum 101 due to the action of the electric field. As a result, the electrostatic latent image is visualized by the toner particles to form a toner image. The toner image is transferred to the intermediate transfer belt 12a shown in FIG. 1.

[0033] The developing unit 110 includes a developing housing 111 , a developing roller 112 , a first screw feeder 113 , a second screw feeder 114 , and a regulating blade 115 .

[0034] The developing roller 112 has a substantially columnar or cylindrical shape. The developing roller 112 is disposed facing the photosensitive drum 101. The developing roller 112 includes a sleeve 112S and a magnet 112M. The magnet 112M is disposed inside the sleeve 112S. The magnet 112M includes an S1 pole, an N1 pole, an S2 pole, an N2 pole, and an S3 pole. The N1 pole functions as a main pole, the S1 pole and the N2 pole function as transport poles, and the S2 pole functions as a peeling pole. The S3 pole functions as a pumping pole and a regulating pole.

[0035] The sleeve 112S is a non-magnetic cylinder (for example, an aluminum pipe). The sleeve 112S is driven by, for example, a motor to rotate around the magnet 112M in a rotation direction RC.

[0036] Therefore, while the sleeve 112S rotates in the rotation direction RC, the carrier particles are attracted by the magnetic force of the magnet 112M. As a result, a magnetic brush of carrier particles is formed on the surface of the developing roller 112. Specifically, a plurality of magnetic brushes are formed on the surface of the developing roller 112. Each of the plurality of magnetic brushes is made of a plurality of carrier particles. That is, each of the plurality of magnetic brushes is a carrier particle cluster standing on the surface of the developing roller 112. The toner particles are carried on the surface of the carrier particles. That is, the toner particles are carried on the surface of the developing roller 112 while being carried on the magnetic brush.

[0037] The regulating blade 115 is disposed at a predetermined interval from the developing roller 112. The regulating blade 115 regulates the length of the magnetic brush formed on the surface of the developing roller 112.

[0038] The developing housing 111 includes a transport section that accommodates the two-component developer. For example, the transport section has a first transport section 131 and a second transport section 132. In the first transport section 131, the two-component developer is transported in a first transport direction from one end side to the other end side in the axial direction of the developing roller 112. The second transport section 132 communicates with the first transport section 131 at both ends in the axial direction of the developing roller 112. In the second transport section 132, the two-component developer is transported in a second transport direction opposite to the first transport direction.

[0039] Specifically, the second transport section 132 includes a second screw feeder 114. The second screw feeder 114 is rotated in a rotation direction RE and transports the two-component developer in a second transport direction. The first transport section 131 includes a first screw feeder 113. The first screw feeder 113 is rotated in a rotation direction RD and transports the two-component developer in a first transport direction. The first screw feeder 113 supplies the two-component developer to the developing roller 112 while transporting the two-component developer in the first transport direction.

[0040] The toner particles contained in the two-component developer are triboelectrically charged between themselves and the carrier particles contained in the two-component developer, for example, while being circulated and transported in the first transport direction and the second transport direction.

[0041] The toner container 116 has a storage section R1 that stores replenishment toner particles. The replenishment toner particles are replenished from the storage section R1 of the toner container 116 to the second conveying section 132 of the developing section 110. The toner container 116 includes a supply amount adjustment member 116a. The supply amount adjustment member 116a adjusts the amount of toner replenished. The amount of toner replenished is the amount of toner replenished from the toner container 116 to the second conveying section 132. The supply amount adjustment member 116a is composed of, for example, a screw shaft whose rotation operation is controlled by the control section 20.

[0042] The image forming unit 11 further includes a drive unit 23 and a voltage application unit 21 .

[0043] The driving unit 23 drives and rotates the photoconductor drum 101, the developing roller 112, the first screw feeder 113, the second screw feeder 114, and the supply amount adjusting member 116a. The driving unit 23 includes, for example, a motor and a gear mechanism.

[0044] The voltage application unit 21 applies a development bias to the development roller 112. The development bias is a voltage in which an AC voltage is superimposed on a DC voltage. The AC voltage is, for example, a square wave with a duty ratio of 50%. Specifically, the voltage application unit 21 has a DC power source and an AC power source. As a result, the development bias potential on the surface of the development roller 112 is a potential Vdc.

[0045] The charging unit 102 charges the surface of the photoconductor drum 101 to a predetermined potential V0 (V). After the surface of the photoconductor drum 101 is charged to the predetermined potential V0 (V) by the charging unit 102, when a laser beam having a predetermined intensity or a predetermined amount of light is irradiated to a predetermined area by the exposure unit 13, an electrostatic latent image is formed on the surface of the photoconductor drum 101, and the potential of the electrostatic latent image changes from the potential V0 to the potential VL (V). The potential difference between the potential VL and the potential Vdc becomes the potential difference that moves the charged toner particles from the developing roller 112 to the electrostatic latent image. Specifically, the toner particles carried by the developing roller 112 are electrically attracted and fly toward the electrostatic latent image on the photoconductor drum 101. As a result, a toner image is formed on the electrostatic latent image on the photoconductor drum 101.

[0046] The configuration of the image forming apparatus 100 according to the embodiment will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the configuration of the image forming apparatus 100. As shown in Fig. 3, the control unit 20 includes an image formation execution unit 20a, an exposure and cleaning execution unit 20b, and an aging execution unit 20c. The processor of the control unit 20 executes a computer program stored in the storage device of the storage unit 80, thereby functioning as the image formation execution unit 20a, the exposure and cleaning execution unit 20b, and the aging execution unit 20c.

[0047] When the image forming execution unit 20a receives a print job from the operation unit 120, it controls the image forming unit 10, the feeding unit 30, the conveying unit 40, the fixing unit 50, the discharge unit 60, the document feeding unit 90, and the scanner unit 91. The print job indicates an instruction to form an image on a sheet P.

[0048] The control unit 20 ages the photoconductor drum 101. Specifically, the aging execution unit 20c controls the drive unit 23 so that the photoconductor drum 101 rotates for a second predetermined time. The second predetermined time is longer than the first predetermined time. As a result of the rotation of the photoconductor drum 101, discharge products accumulated on the surface of the photoconductor drum 101 are polished by the cleaning unit 103, so that the discharge products can be removed.

[0049] In the image forming apparatus 100 according to this embodiment, when the control unit 20 receives a command to execute a preparatory operation, the control unit 20 cleans the exposure unit 13 with the cleaning unit 13a and simultaneously ages the photoconductor drum 101. Specifically, the exposure / cleaning execution unit 20b controls the cleaning unit 13a to clean the exposure unit 13 for a first predetermined time from the start time. Furthermore, the aging execution unit 20c controls the drive unit 23 to rotate the photoconductor drum 101 for a second predetermined time from the start time.

[0050] Therefore, according to this embodiment, the execution time of the preparatory operation can be shortened to the second specified time, instead of the sum of the first specified time and the second specified time.

[0051] More specifically, in the image forming apparatus 100 according to this embodiment, the control unit 20 executes a first preparatory operation (high quality mode) before forming an image on the sheet P. The first preparatory operation includes an operation for cleaning the exposure unit 13 and aging the photoconductor drum 101 without supplying toner from the developing unit 110 to the photoconductor drum 101.

[0052] Specifically, the exposure cleaning execution unit 20b controls the cleaning unit 13a to clean the exposure unit 13 for a first predetermined time from when the power supply unit 104 turns on the power. Moreover, the aging execution unit 20c controls the drive unit 23 to rotate the photoconductor drum 101 without supplying toner from the development unit 110 to the photoconductor drum 101 for a second predetermined time from when the power supply unit 104 turns on the power.

[0053] Therefore, according to this embodiment, the execution time of the first preparatory operation (high quality mode) can be shortened to the second specified time, rather than the sum of the first specified time and the second specified time.

[0054] Furthermore, in the image forming apparatus 100 according to this embodiment, the control unit 20 executes a second preparatory operation (low quality mode) before forming an image on the sheet P. The second preparatory operation includes an operation of cleaning the exposure unit 13 and aging the photoconductor drum 101 while supplying toner from the developing unit 110 to the photoconductor drum 101.

[0055] Specifically, the exposure cleaning execution unit 20b controls the cleaning unit 13a to clean the exposure unit 13 for a first predetermined time from when the power supply unit 104 turns on the power. Moreover, the aging execution unit 20c controls the voltage application unit 21 and the drive unit 23 to rotate the photoconductor drum 101 while supplying toner from the development unit 110 to the photoconductor drum 101 for a second predetermined time from when the power supply unit 104 turns on the power.

[0056] Therefore, according to this embodiment, the execution time of the second preparatory operation (low quality mode) can be shortened to the second specified time, rather than the sum of the first specified time and the second specified time.

[0057] Furthermore, the control unit 20 further includes a selection unit 20d. The selection unit 20d selects either a first preparatory operation (high quality mode) or a second preparatory operation (low quality mode) before forming an image on the sheet P. Specifically, when the selection unit 20d receives a signal indicating the first preparatory operation (high quality mode) from the operation unit 120, the selection unit 20 stores a signal indicating the first preparatory operation (high quality mode) in the storage unit 80, and the control unit 20 executes the first preparatory operation (high quality mode) when the power supply unit 104 is turned on. Also, when the selection unit 20d receives a signal indicating the second preparatory operation (low quality mode) from the operation unit 120, the selection unit 20 stores a signal indicating the second preparatory operation (low quality mode) in the storage unit 80, and the control unit 20 executes the second preparatory operation (low quality mode) when the power supply unit 104 is turned on. Furthermore, when the selection unit 20d stores a signal indicating the second preparatory operation (low quality mode) in the memory unit 80, the control unit 20 may execute the first preparatory operation (high quality mode) when the time between when the power is turned off and when the power is turned on by the power supply unit 104 is greater than or equal to a predetermined time.

[0058] According to this embodiment, it is possible to select either the first preparatory operation or the second preparatory operation.

[0059] Next, an example of the process of the control unit 20 according to the present embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of the process of the control unit 20. The process of the control unit 20 according to the present embodiment includes steps S101 to S106.

[0060] First, in step S101, the power supply unit 104 is turned on. Then, the process proceeds to step S102.

[0061] Next, in step S102, the control unit 20 determines what mode is stored in the storage unit 80. If the control unit 20 determines that it is the first preparatory operation (high quality mode), the process proceeds to steps S103 and S104.

[0062] In step S103, the exposure cleaning execution unit 20b controls the cleaning unit 13a to clean the exposure unit 13 for a first predetermined time. In step S104, the aging execution unit 20c controls the drive unit 23 to rotate the photoconductor drum 101 without supplying toner from the development unit 110 to the photoconductor drum 101 for a second predetermined time. Then, the process ends.

[0063] On the other hand, if the control unit 20 determines that the operation is the second preparatory operation (low quality mode), the process proceeds to step S105 and step S106.

[0064] In step S105, the exposure cleaning execution unit 20b controls the cleaning unit 13a to clean the exposure unit 13 for a first predetermined time. In step S106, the aging execution unit 20c controls the voltage application unit 21 and the drive unit 23 to rotate the photoconductor drum 101 while supplying toner from the development unit 110 to the photoconductor drum 101 for a second predetermined time. Then, the process ends.

[0065] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. Furthermore, components across different embodiments may be appropriately combined. The drawings are mainly shown schematically for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are only examples and are not particularly limited, and various changes are possible within a range that does not substantially deviate from the effects of the present invention. [Industrial Applicability]

[0066] The present invention relates to an image forming apparatus and has industrial applicability. [Explanation of symbols]

[0067] 10 Image forming section 13 Exposure section 13a Cleaning Department 20 Control section 100 Image forming device 101 Photoconductor drum 110 Development section

Claims

1. an image forming unit that forms an image on a sheet; A control unit that controls the image forming unit; Equipped with The image forming unit includes: A photoconductor drum; an exposure unit that forms an electrostatic latent image corresponding to the image on the photosensitive drum; a developing section for developing the electrostatic latent image with toner; a cleaning unit that cleans the exposure unit; Including, The control unit cleans the exposure unit with the cleaning unit and ages the photosensitive drum at the same time.

2. The control unit executes a first preparation operation before forming the image on the sheet, 2 . The image forming apparatus according to claim 1 , wherein the first preparation operation includes an operation for cleaning the exposure unit and aging the photosensitive drum without supplying the toner from the development unit to the photosensitive drum.

3. The control unit executes a second preparation operation before forming the image on the sheet, 2 . The image forming apparatus according to claim 1 , wherein the second preparation operation includes an operation of cleaning the exposure unit and aging the photoconductor drum while supplying the toner from the development unit to the photoconductor drum.

4. The control unit has a selection unit that selects one of a first preparatory operation and a second preparatory operation before forming the image on the sheet, the first preparation operation includes an operation of cleaning the exposure unit and aging the photoconductor drum without supplying the toner from the development unit to the photoconductor drum, 2 . The image forming apparatus according to claim 1 , wherein the second preparation operation includes an operation of cleaning the exposure unit and aging the photoconductor drum while supplying the toner from the development unit to the photoconductor drum.

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