Image forming apparatus

Abstract

The present application provides an image forming apparatus capable of stabilizing an image at low cost. According to one embodiment, an image forming apparatus includes a photoreceptor, a static eliminator, a charger, an exposer, a developer, and a processor. The de-energizer emits de-energizing light which irradiates the photoreceptor. The electrifying device electrifies the photoreceptor which is de-energized by the de-energizing device. The exposure device forms an electrostatic latent image on the photoreceptor charged by the charger. The developer supplies toner to the photoreceptor on which the electrostatic latent image is formed by the exposer. The toner sensor outputs a signal corresponding to a toner adhesion amount on an image carrier to which toner is transferred from a photoreceptor. The memory stores, for each type of toner, a target value including a correction value for image stabilization control that stabilizes an image. The processor executes image stabilization control that performs setting such that an output value of the toner sensor becomes a target value including the correction value for each type of toner.

Description

Technical Field

[0001] Embodiments of the present invention relate to an image forming apparatus. Background Art

[0002] In addition, an electrophotographic image forming apparatus forms a color image using a developer containing toners of multiple colors (e.g., yellow, magenta, cyan, and black). The electrophotographic image forming apparatus measures the amount of toner attached to a transfer member using a toner sensor, and performs image stabilization control so that the toner amount measured by the toner sensor reaches a target value.

[0003] On the other hand, in order to reduce the size and cost of an image forming device, it is sometimes desirable to reduce the distance between the units in the device or to omit components. In the design of miniaturization and cost reduction, a part of the anti-static light irradiated to the photosensitive drum in the image forming device sometimes enters the toner sensor. Such a phenomenon can be prevented by installing a light shielding wall that blocks the anti-static light in the image forming device, but there is a problem that the structure runs counter to the trend of miniaturization and cost reduction. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an image forming apparatus capable of stabilizing an image at low cost.

[0005] According to an embodiment, an image forming device includes a photoreceptor, a charge remover, a charger, an exposure device, a developer, and a processor. The charge remover emits a charge-removing light that is irradiated on the photoreceptor. The charger charges the photoreceptor that has been charged by the charge remover. The exposure device forms an electrostatic latent image on the photoreceptor that has been charged by the charger. The developer supplies toner to the photoreceptor on which the electrostatic latent image has been formed by the exposure device. The toner sensor outputs a signal corresponding to the amount of toner attached to the image carrier on which the toner has been transferred from the photoreceptor. The memory stores target values ​​including correction values ​​for image stabilization control that stabilizes the image for each type of toner. The processor executes image stabilization control that is set so that the output value of the toner sensor becomes the target value including correction values ​​for each type of toner.

[0006] Description of Reference Numerals

[0007] 1: digital multifunction peripheral (image forming device), 2: printer, 3: operation panel, 4: scanner, 5: system controller, 21: intermediate transfer belt (image carrier), 22: secondary transfer roller, 24: toner sensor, 100: exposure device, 101: processor, 104: storage device, 105: communication interface, 110: developer, 122: photosensitive drum, 126: charger, 128: primary transfer roller, 130: cleaner, 132: de-staticizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a diagram showing a configuration example of a digital multifunction peripheral as an image forming apparatus according to an embodiment.

[0009] Figure 2 This is a diagram showing a configuration example of an image forming station in a printer of a digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0010] Figure 3 This is a block diagram showing a configuration example of a control system in a digital multifunction peripheral as an image forming apparatus according to an embodiment.

[0011] Figure 4 This is a diagram showing a configuration example of a toner sensor in a printer of a digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0012] Figure 5 This is a diagram showing an example of the sensor sensitivity of a toner sensor in a printer of a digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0013] Figure 6 This is a diagram showing an example of spectral reflectance corresponding to each color toner used in a printer of a digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0014] Figure 7 The diagram shows an example of detecting the amount of black toner deposited on a transfer belt used in a printer of a digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0015] Figure 8 The diagram shows an example of detecting the amount of yellow toner deposited on a transfer belt used in a printer of a digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0016] Fig. 9 This is a diagram showing an example of the relationship between the sensor sensitivity of a toner sensor and a set value in a printer of a digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0017] Fig.10 The figure shows a setting example of whether or not correction according to the wavelength of static-eliminating light is required for each color toner in the digital multifunction peripheral as the image forming apparatus according to the embodiment.

[0018] Fig.11 This is a flowchart for explaining a process of updating a correction value for a target value of image stabilization control in a digital multifunction peripheral as an image forming apparatus according to an embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, the present embodiment will be described with reference to the drawings.

[0020] First, the configuration of a digital multifunction peripheral (MFP; Multi-Functional Peripheral) 1 as an image forming apparatus according to the embodiment will be described.

[0021] Figure 1 1 is a block diagram showing a configuration example of a digital multifunction peripheral 1 as an image forming apparatus according to the embodiment.

[0022] like Figure 1 As shown, the digital multifunction peripheral 1 includes a printer 2, an operation panel 3, a scanner 4, a system controller 5, etc. The digital multifunction peripheral 1 is an example of an image forming apparatus placed in a workplace or the like.

[0023] The printer 2 is an image forming device that forms an image on a recording medium. The printer 2 provided in the digital multifunction machine 1 is an image forming device that forms an image on a recording medium by an electrophotographic method. The printer 2 forms an image (toner image) on a recording medium such as paper by using a toner. The recording medium on which the printer 2 forms an image may be any recording medium that can form an image, and is not limited to paper, but may also be cloth, a plastic film or sheet, etc.

[0024] The scanner 4 is provided on the upper part of the main body of the digital multifunction machine 1. The scanner 4 is a device that optically reads the image of the original document. For example, the scanner 4 reads the image of the original document placed on the original document table glass. In addition, the scanner 4 may also be a structure including a component that reads the image of the original document fed by an automatic document feeder (ADF: Auto Document Feeder).

[0025] The operation panel 3 is a user interface. The operation panel 3 has a display unit (display), a touch panel, and operation buttons. The operation panel 3 displays operation instructions on the display unit. The operation panel 3 receives operation instructions from the user through the touch panel and the operation buttons. For example, the operation panel 3 sets the touch panel on the display screen of the display unit to detect the part touched by the user on the display screen of the display unit.

[0026] The system controller 5 controls the entire digital multifunction machine 1. The system controller 5 receives operation instructions input to the operation panel 3 and controls the operation of each unit. In addition, the system controller 5 receives operation instructions from an external device connected via an interface and controls the operation of each unit. For example, when an instruction is given to form an image on a recording medium, the system controller 5 controls the printer 2 to cause the printer 2 to perform image formation on the recording medium.

[0027] Next, the structure of the printer 2 will be described.

[0028] like Figure 1 As shown, the printer 2 has a medium supply mechanism 13, a conveying mechanism 15, a plurality of image forming stations SY, SM, SC, SK, an intermediate transfer belt (transfer belt) 21, a secondary transfer roller 22, a support roller 23, a toner sensor 24, a transfer belt cleaner 25, and a fuser 26, etc.

[0029] The medium supply mechanism 13 has a plurality of paper supply boxes 321, 322, and 323. The number of paper supply boxes may be several. Each paper supply box 321, 322, and 323 stores paper as recording medium S. The paper as recording medium S stored in each paper supply box may be paper of different sizes or different types. Pickup rollers 341, 342, and 343 are respectively configured for each paper supply box 321, 322, and 323. The pickup rollers 341, 342, and 343 take out paper as recording medium one by one from the paper supply boxes 321, 322, and 323. The pickup rollers 341, 342, and 343 supply the recording medium S taken out respectively to the conveying mechanism 15.

[0030] The conveying mechanism 15 conveys the recording medium S. The conveying mechanism 15 includes first conveying rollers 521, 522, 523, a second conveying roller 54, and a registration roller 56 in a conveying path before forming an image on the recording medium S. The conveying mechanism 15 conveys the recording medium S supplied by the pickup rollers 341, 342, 343 from the first conveying rollers 521, 522, 523 to the second conveying roller 54. In the conveying mechanism 15, the second conveying roller 54 further conveys the recording medium S to the registration roller 56.

[0031] The registration roller 56 of the conveying mechanism 15 conveys the recording medium S to the secondary transfer position according to the timing of transferring the image from the intermediate transfer belt 21 to the recording medium S at the secondary transfer position described later. The conveying mechanism 15 forms a conveying path to convey the recording medium S to which the image has been transferred from the intermediate transfer belt 21 to the fixing device 26. Furthermore, the conveying mechanism 15 includes a third conveying roller 58 for discharging the paper to the paper discharge section, a conveying mechanism for conveying the recording medium S to the reversing section for reversing the recording medium S, and the like.

[0032] Each image forming station SY, SM, SC, and SK forms an image using toner. In the present embodiment, the image forming station SY forms a yellow image. The image forming station SM forms a magenta image. The image forming station SC forms a cyan image. The image forming station SK forms a black image. Each image forming station SY, SM, SC, and SK transfers the image formed using toner to the intermediate transfer belt 21. The configuration of each image forming station SY, SM, SC, and SK will be described in detail later.

[0033] The intermediate transfer belt 21 is a medium (image carrier) that holds the images transferred by the image forming stations SY, SM, SC, and SK. Figure 1 The intermediate transfer belt 21 is an endless belt as shown. Figure 1 The intermediate transfer belt 21 moves the images transferred by the image forming stations SY, SM, SC, and SK to a position where the secondary transfer roller 22 and the backup roller 23 face each other.

[0034] The secondary transfer roller 22 and the backup roller 23 constitute a transfer section (secondary transfer section) for transferring an image from the intermediate transfer belt 21 to a recording medium. The position where the secondary transfer roller 22 and the backup roller 23 face each other is a secondary transfer position for transferring an image from the intermediate transfer belt 21 to a recording medium. The secondary transfer roller 22 and the backup roller 23 sandwich the intermediate transfer belt 21 and the recording medium at the secondary transfer position.

[0035] The support roller 23 supports the intermediate transfer belt 21. The support roller 23 is a driving roller that drives the intermediate transfer belt 21. The secondary transfer roller 22 faces the support roller 23 across the intermediate transfer belt 21. The secondary transfer roller 22 transfers (secondary transfer) the image formed by the toner on the transfer surface of the intermediate transfer belt 21 onto the surface of the recording medium.

[0036] The toner sensor 24 is a sensor for detecting the amount (density) of toner. The toner sensor 24 detects the amount of toner attached to the intermediate transfer belt 21. The toner sensor 24 is arranged to face the transfer surface of the intermediate transfer belt 21. The toner sensor 24 is provided between the transfer position (primary transfer position) where the image is transferred from each image forming station to the secondary transfer position in the moving direction a of the intermediate transfer belt 21. The toner sensor 24 outputs the detected amount of toner attached to the system controller 5.

[0037] like Figure 1 As shown, the transfer belt cleaner 25 is arranged between the secondary transfer position and the primary transfer position in the moving direction a of the intermediate transfer belt 21. The transfer belt cleaner 25 removes toner on the intermediate transfer belt 21. For example, the transfer belt cleaner 25 removes toner remaining on the transfer surface of the intermediate transfer belt 21 after the image is transferred from the intermediate transfer belt 21 to the recording medium.

[0038] The fixing device 26 fixes the image formed by the toner transferred to the recording medium to the recording medium. The fixing device 26 is arranged in the conveying path of the recording medium after passing the secondary transfer position. The fixing device 26 has a pressure roller and a heating roller facing each other. The fixing device 26 applies heat and pressure to the recording medium by conveying the recording medium between the heating roller and the pressure roller facing each other. The fixing device 26 fixes the toner image transferred to the recording medium by heating in a pressurized state.

[0039] Next, the configuration of each image forming station SY, SM, SC, and SK in the printer 2 as the image forming apparatus according to the embodiment will be described in detail.

[0040] Figure 2 1 is a diagram showing a configuration example of each of the image forming stations SY, SM, SC, and SK in the printer 2 .

[0041] like Figure 2 As shown, each image forming station SY, SM, SC, SK includes an exposure device 100, a developer 110, a photosensitive drum 122, a charger 126, a primary transfer roller 128, a photosensitive body cleaner 130, and a static remover 132. In this embodiment, each image forming station SY, SM, SC, SK includes Figure 2 The structure shown.

[0042] The photosensitive drum 122 is an image bearing member having a photosensitive layer 124 on its surface. The photosensitive drum 122 moves in a direction (a) corresponding to the movement direction of the intermediate transfer belt 21. Figure 2 Around the photosensitive drum 122, a charger 126, an exposure device 100, a developer 110, a primary transfer roller 128, an intermediate transfer belt 21, a photosensitive body cleaner 130, and a static remover 132 are arranged.

[0043] The charger 126 uniformly charges the photosensitive layer 124 on the surface of the photosensitive drum 122. The charger 126 uniformly charges the photosensitive layer 124 on the surface of the photosensitive drum 122 to negative polarity, for example.

[0044] The exposure device 100 forms a static pattern (static latent image) corresponding to the image on the surface of the photosensitive drum 122. The exposure device 100 irradiates the surface of the photosensitive drum 122 with light L controlled to emit light based on image data. For example, the exposure device 100 irradiates the surface of the photosensitive drum 122 with light L emitted based on image data via an optical system such as a polygon mirror. The exposure device 100 may also be a device that emits a plurality of lasers that are guided to the photosensitive drum 122 of a plurality of image forming stations. In addition, the exposure device 100 may also be a light emitting device provided for each of the plurality of image forming stations.

[0045] The developer 110 develops the electrostatic latent image formed on the surface of the photosensitive drum 122 with a developer. The developer 110 supplies the developer D to the surface of the photosensitive drum 122 exposed by the exposure device 100. The developer 110 of each image forming station develops the image in its corresponding color. The developer D is a mixture of a carrier composed of magnetic particles and a toner. When the developer D is stirred, the toner is triboelectrically charged. As a result, the toner adheres to the electrostatic latent image formed on the surface of the photosensitive drum 122 by electrostatic force.

[0046] For example, the developer 110 of the image forming station SY develops the electrostatic latent image on the photosensitive drum 122 with a yellow toner. The developer 110 of the image forming station SM develops the electrostatic latent image on the photosensitive drum 122 with a magenta toner. The developer 110 of the image forming station SC develops the electrostatic latent image on the photosensitive drum 122 with a cyan toner. The developer 110 of the image forming station SK develops the electrostatic latent image on the photosensitive drum 122 with a black toner.

[0047] The image (toner image) developed by the toner on the surface of the photosensitive drum 122 moves to a position corresponding to the primary transfer roller 128 by the rotation of the photosensitive drum 122. The primary transfer roller 128 faces the photosensitive drum 122 with the intermediate transfer belt 21 interposed therebetween. The primary transfer roller 128 abuts against the surface of the photosensitive drum 122 with the intermediate transfer belt 21 interposed therebetween. The primary transfer roller 128 transfers (primary transfer) the toner image on the surface of the photosensitive drum 122 to the intermediate transfer belt 21.

[0048] The photoconductor cleaner 130 is arranged downstream of the position where the toner image on the surface of the photoconductor drum 122 is transferred onto the intermediate transfer belt 21 in the circumferential direction of the photoconductor drum 122. The photoconductor cleaner 130 removes the toner on the surface of the photoconductor drum 122. That is, the photoconductor cleaner 130 removes the toner remaining on the surface of the photoconductor drum 122 after the primary transfer of the toner image from the photoconductor drum 122 to the intermediate transfer belt 21 is performed.

[0049] The static eliminator 132 is arranged downstream of the position of the photosensitive body cleaner 130 in the circumferential direction of the photosensitive drum 122. The static eliminator 132 emits light (static eliminator light) for removing the charge remaining in the photosensitive body layer 124 located on the surface of the photosensitive drum 122. The static eliminator 132 emits the static eliminator light through a light source composed of an LED or the like. The static eliminator 132 is configured to irradiate the static eliminator light emitted by the light source onto the surface of the photosensitive drum 122.

[0050] In the image forming apparatus according to the present embodiment, part of the light (static light) emitted by the light source of the static eliminator 132 of the image forming station SK enters the toner sensor 24 as leakage light. Figure 2 The example shown is Figure 2As shown by the dotted line in , the leaked light from the light source of the static eliminator 132 is reflected by the intermediate transfer belt 21 and is incident on the toner sensor 24. The image forming apparatus according to the present embodiment uses the toner sensor 24 to measure the toner adhesion amount with high accuracy without providing a light shielding wall to block the leaked light from the light source of the static eliminator 132. That is, the image forming apparatus according to the present embodiment is based on the structure that a part of the static eliminator light (the leaked light) from the static eliminator 132 is incident on the toner sensor 24.

[0051] Next, the configuration of a control system in the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment will be described.

[0052] Figure 3 1 is a block diagram showing a configuration example of a control system in the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment.

[0053] like Figure 3 As shown, the system controller 5 includes a processor 101, a ROM 102, a RAM 103, a storage device 104, a communication interface (I / F) 105, etc. The processor 101 of the system controller 5 is connected to each unit in the digital multifunction peripheral 1 via various interfaces.

[0054] The processor 101 implements various processes by executing programs. The processor 101 is, for example, a CPU. The processor 101 is connected to the ROM 102, RAM 103, storage device 104, and communication interface (I / F) 105. The processor 101 is also connected to various components in the printer 2, the operation panel 3, and the scanner 4 via interfaces.

[0055] The ROM 102 is a non-volatile memory that cannot be rewritten. The ROM 102 operates as a program memory that stores programs. The RAM 103 operates as a working memory or a cache memory. The processor 101 executes various processes by executing programs stored in the ROM 102 or the storage device 104 using the RAM 103 .

[0056] The storage device 104 is a rewritable nonvolatile memory. For example, the storage device 104 is composed of a storage device such as an HDD (hard disk drive) or an SSD (solid state drive). The storage device 104 stores data such as control data, control programs, and setting information. The storage device 104 also stores image data, etc.

[0057] The communication I / F 105 is an interface for data communication with an external device. For example, the communication I / F 105 communicates with a user terminal such as a PC and a portable terminal via a network. The communication I / F 105 can also input a print request (print job) of an image from a user terminal such as a PC.

[0058] Next, the operation of image forming processing in the printer 2 as the image forming apparatus according to the embodiment will be described.

[0059] The digital multifunction peripheral 1 executes an image forming process of acquiring an image formed on a recording medium S and printing the acquired image on the recording medium S via the printer 2. For example, when a copy instruction is given via the operation panel 3, the processor 101 of the system controller 5 executes a process of printing an image of a document read by the scanner 4 on the recording medium S via the printer 2.

[0060] When executing image forming processing, the processor 101 of the system controller 5 takes in the recording medium S stored in the storage section via the medium supply mechanism 13 . The processor 101 conveys the recording medium S supplied from the medium supply mechanism 13 to the front of the registration roller 56 in the printer 2 via the conveyance mechanism 15 .

[0061] Furthermore, the processor 101 of the system controller 5 generates images formed by the image forming stations SY, SM, SC, and SK based on the image (print image) to be printed on the recording medium S. For example, the processor 101 generates images of respective colors (yellow, magenta, cyan, and black) formed by the image forming stations SY, SM, SC, and SK based on the print image. When the processor 101 generates images of respective colors based on the print image, it causes each image forming station to form the generated images of respective colors.

[0062] In each image forming station SY, SM, SC, SK, the charger 126 charges the photosensitive layer 124 of the photosensitive drum 122 by the charging bias voltage from the power supply circuit. The processor 101 adjusts (sets) the charging bias voltage by image stabilization control (image quality maintenance control). The exposure device 100 irradiates the photosensitive drum 122 of each image forming station SY, SM, SC, SK with light for forming an electrostatic latent image corresponding to an image of each color. The processor 101 adjusts (sets) the power of the light output by the exposure device 100 by image stabilization control. In each image forming station SY, SM, SC, SK, an electrostatic latent image is formed on the photosensitive layer 124 of the photosensitive drum 122 by the light irradiated from the exposure device 100.

[0063] Each image forming station SY, SM, SC, SK develops the electrostatic latent image on the photosensitive drum 122 using the color toner contained in the developer 110. In each image forming station SY, SM, SC, SK, the developing roller rotates while carrying the developer D containing the toner of each color supplied from the developer container. Here, the concentration ratio of the developer D is adjusted (set) by image stabilization control. The developing roller carrying the developer D is applied with a development bias voltage from a power supply circuit. The developer 110 supplies the toner in the developer carried by the developing roller to the electrostatic latent image through the potential difference (contrast potential) between the potential on the developing roller and the electrostatic latent image on the photosensitive drum 122. The processor 101 adjusts (sets) the development bias voltage and the contrast potential, etc. by image stabilization control.

[0064] In each of the image forming stations SY, SM, SC, and SK, the photosensitive drum 122 moves the image (toner image) developed by the developer 110 to a position (primary transfer position) opposite to the primary transfer roller 128. At the primary transfer position, the photosensitive drum 122 faces the primary transfer roller 128 with the intermediate transfer belt 21 interposed therebetween. A primary transfer bias voltage from a power supply circuit is applied to the primary transfer roller 128. The toner image on the photosensitive drum 122 is transferred to the intermediate transfer belt 21 at the primary transfer position by the primary transfer roller to which the primary transfer bias voltage is applied. When forming a color image, each of the image forming stations SY, SM, SC, and SK transfers the toner images of each color onto the intermediate transfer belt 21 in an overlapping manner. Thus, a color image obtained by overlapping the toner images of each color is transferred onto the intermediate transfer belt 21.

[0065] The intermediate transfer belt 21 moves the transferred toner image to a position (secondary transfer position) opposite to the secondary transfer roller 22. With respect to the recording medium S, the registration roller 56 sends the recording medium S to the secondary transfer position in accordance with the position and timing of the image transferred on the intermediate transfer belt 21. Thus, the secondary transfer roller 22 and the backup roller 23 convey the intermediate transfer belt 21 and the recording medium S in a state of sandwiching and overlapping each other at the secondary transfer position. A secondary transfer bias voltage is applied to the secondary transfer roller 22 from a power supply circuit. The toner image on the intermediate transfer belt 21 is transferred to the recording medium S at the secondary transfer position by the secondary transfer roller 22 to which the secondary transfer bias voltage is applied.

[0066] The recording medium S that has passed through the secondary transfer position is conveyed to the fixing device 26. The fixing device 26 fixes the toner image transferred from the intermediate transfer belt 21 to the recording medium S at the secondary transfer position to the recording medium S. The fixing device 26 applies heat and pressure to the recording medium S to which the toner image has been transferred so as to fix the toner image to the recording medium S. The recording medium S that has passed through the fixing device 26 is discharged from the paper discharge portion in a state in which the toner image is fixed.

[0067] Next, the image stabilization control using the toner sensor 24 in the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment will be described.

[0068] The system controller 5 executes image stabilization control, which performs adjustment (setting) for stabilizing the image formed on the recording medium S by the image forming process of the printer 2. The image stabilization control is performed, for example, at a predetermined cycle. In addition, the image stabilization control may be performed every time a predetermined execution condition is satisfied, or may be performed at an arbitrary timing. The image stabilization control is performed using the output of the toner sensor 24.

[0069] Next, density adjustment using the output of the toner sensor 24 will be described as an example of image stabilization control. However, the image stabilization control may be any process executed using the output of the toner sensor 24, and may be a process of changing a set value such as image position adjustment or image gradation adjustment.

[0070] Density adjustment, which is an example of image stabilization control, is a process of adjusting the density of an image formed on the recording medium S by the image forming process of the printer 2. The density of the image formed on the recording medium S changes according to the amount (density) of toner supplied from the developing roller to the electrostatic latent image when the electrostatic latent image on the photosensitive drum 122 is developed. In density adjustment, the system controller 5 adjusts (sets) setting values ​​for various controls so that the output value of the toner sensor 24 becomes a target value indicating the amount of toner adhesion as a target. For example, the system controller 5 adjusts setting values ​​such as charging bias, developing bias, exposure power, and developer density ratio so that the output value of the toner sensor 24 becomes a target value.

[0071] The reference target value in the density adjustment is determined based on the relationship between the output value of the toner sensor 24 in the digital multifunction peripheral 1 and the amount of toner attached to the transfer belt 21. The reference target value for density adjustment is stored in a memory such as the storage device 104 for each color of toner. However, the digital multifunction peripheral 1 involved in this embodiment stores a target value including a correction value in a memory such as the storage device 104 for the color of the toner that requires correction described later. The memory such as the storage device 104 stores a target value obtained by adding a correction value to the reference target value as a target value including a correction value for each toner. In addition, the memory such as the storage device 104 can also store a reference target value and a correction value as a target value including a correction value for each toner. The digital multifunction peripheral 1 performs image stabilization control for the toner of the type for which the correction value is set so as to obtain a target value obtained by adding a correction value to the reference target value.

[0072] Next, the toner sensor 24 in the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment will be described.

[0073] Figure 4 1 is a diagram showing a configuration example of the toner sensor 24 in the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment.

[0074] The toner sensor 24 is a sensor for measuring the amount of toner adhesion by reading the reflected light from the belt surface using the smoothness of the surface of the transfer belt 21 and the unevenness caused by the toner. The toner sensor 24 is composed of, for example, a reflective sensor that combines a light emitting element and a light receiving element. An image forming device that forms a color image uses toners of multiple colors. Toners have different optical properties depending on the color. Therefore, Figure 4 The toner sensor 24 of the illustrated configuration example uses one light emitting element and two light receiving elements to read the adhesion amount of toner of each color with high accuracy.

[0075] exist Figure 4 In the illustrated configuration example, the toner sensor 24 includes a light emitting element 201, a first light receiving element 202, and a second light receiving element 203. The light emitting element 201 emits detection light that is irradiated to a portion (the surface of the transfer belt 21) that serves as a detection surface. The light emitting element 201 is composed of, for example, an LED. The first light receiving element 202 and the second light receiving element 203 are composed of a PD (photodiode) or a PTr (phototransistor). The first light receiving element 202 is a regular reflection light receiving element that detects regular reflection light on the detection surface for light (incident light) from the light emitting element 201. The second light receiving element 203 is a diffuse reflection light receiving element that detects diffuse reflection light on the detection surface.

[0076] The amount of toner attached to the detection surface (the surface on the transfer belt 21) is detected based on the detection result of the first light receiving element 202 and the detection result of the second light receiving element 203. For example, the black toner attached to the transfer belt 21 as the detection surface hardly diffusely reflects the light (incident light) irradiated from the light emitting element 201. Therefore, when the black toner is attached to the detection surface, the output value of the second light receiving element 203 hardly increases. On the other hand, when the black toner is attached to the detection surface, the first light receiving element 202 outputs a value corresponding to the amount of toner attached.

[0077] In contrast, yellow, cyan, magenta, and other toners diffusely reflect incident light in accordance with the characteristics of their respective colors. Therefore, when yellow, cyan, and magenta toners are attached to the detection surface, the second light receiving element 203 receives light diffused by the toners. For example, when yellow toner is attached to the detection surface, the second light receiving element 203 receives light diffused by the yellow toner, and the output value increases in accordance with the characteristics of yellow.

[0078] As described above, the toner sensor 24 outputs information indicating the amount of toner attached to each color by combining the output value of the first light receiving element 202 and the output value of the second light receiving element 203. In other words, the amount of toner attached to the detection surface is detected (measured) by combining the output value of the first light receiving element 202 and the output value of the second light receiving element 203.

[0079] It should be noted that the toner sensor 24 may also be a sensor having a beam splitter disposed on the optical path from the light emitting side to the light receiving side. In this case, the toner sensor is composed of a light emitting element, a beam splitter, and a first and a second light receiving element. The beam splitter splits the light from the light emitting element into a P wave light (regular reflection light) and an S wave light (diffuse reflection light). The first light receiving element receives the P wave light (regular reflection light) from the beam splitter. The second light receiving element receives the S wave light (diffuse reflection light) from the beam splitter.

[0080] The toner sensor 24 configured as described above may sometimes have a reading difference (sensor sensitivity) in the output value (reading value) for a certain toner attachment amount. Therefore, in order to make the toner attachment amount on the transfer belt 21 constant, it is necessary to set a target value in the density adjustment corresponding to each sensor sensitivity of the toner sensor 24. Generally, the reference target value in the density adjustment is set based on the sensor sensitivity determined from the information of the toner sensor at the manufacturing stage, the information of the digital multifunction machine 1 at the manufacturing stage, etc. In addition, the reference target value in the density adjustment can also be set based on the reading result of the reference mark for measuring the sensor sensitivity set in advance.

[0081] Figure 5 1 is a diagram showing an example of a value read by the toner sensor 24 regarding the amount of toner deposited on the transfer belt 21 .

[0082] Figure 5 The example shown shows the upper limit reading value and the lower limit reading value of the toner attachment amount by the toner sensor 24. Figure 5 As shown in FIG. 1 , due to the difference in sensor sensitivity, the reading value of the toner sensor 24 for a specific toner adhesion amount differs. A target value is set for each color of toner for the output value of the toner sensor 24. Therefore, a target value for each color of toner of the toner sensor 24 is set corresponding to each sensor sensitivity.

[0083] Next, the influence of the leaked light (static elimination light) emitted by the static eliminator 132 on the output of the toner sensor 24 will be described.

[0084] When the anti-static light has no influence on the output of the toner sensor 24, the toner adhesion amount becomes the predetermined target amount by adjusting the output value of the toner sensor 24 to the reference target value of the concentration adjustment. However, when there is the influence of the leakage light of the anti-static light, even if the output value of the toner sensor 24 is adjusted to the reference target value, the toner adhesion amount may sometimes deviate.

[0085] Figure 6 1 is a diagram showing an example of the amount of black toner deposited when leakage light of the anti-static light enters the toner sensor 24 and when the anti-static light does not enter the toner sensor 24 .

[0086] The toner adhesion amount KTa represents the amount of black toner adhered to the transfer belt 21 when the concentration is adjusted to the reference target value for density adjustment in a state where the leaked light does not enter the toner sensor 24. In addition, the toner adhesion amount KTb represents the amount of black toner adhered to the transfer belt 21 when the concentration is adjusted to the reference target value for density adjustment in a state where the leaked light enters the toner sensor 24. Figure 6 In the example shown, the difference between the toner adhesion amount KTa and the toner adhesion amount KTb is small, and it is considered that the influence on the image printed on the recording medium is actually small.

[0087] Figure 7 1 is a diagram showing an example of the amount of yellow toner deposited when leakage light of the anti-static light enters the toner sensor 24 and when the anti-static light does not enter the toner sensor 24 .

[0088] The toner adhesion amount YTa represents the amount of yellow toner adhered to the transfer belt 21 when the concentration is adjusted to the reference target value of the density adjustment in a state where the leaked light does not enter the toner sensor 24. The toner adhesion amount YTb represents the amount of yellow toner adhered to the transfer belt 21 when the concentration is adjusted to the reference target value of the density adjustment in a state where the leaked light enters the toner sensor 24. Figure 7 In the example shown, the difference between the toner adhesion amount YTa and the toner adhesion amount YTb is large, which is considered to have a large influence on the image actually printed on the recording medium. Therefore, as an image stabilization control, in order to stabilize the adhesion amount of the yellow toner, it is necessary to correct the influence of the leakage light of the static elimination light.

[0089] In addition, if Figure 6 and Figure 7 As shown in FIG. 1 , the effect of leakage light (de-static light) on the amount of yellow toner attached is large, whereas leakage light has no effect (little effect) on the amount of black toner attached. Thus, the effect of de-static light varies depending on the type (color) of toner. Figure 2As shown, the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment has a structure in which leakage light of the static elimination light from the static elimination 132 is incident on the toner sensor 24. Therefore, the digital multifunction peripheral 1 according to the embodiment corrects (corrects) the influence of the leakage light for each type of toner in image stabilization control such as density adjustment.

[0090] Next, the influence of leakage light of static-eliminating light in various toners will be described.

[0091] like Figure 6 and Figure 7 The reason why the presence or absence of the anti-static light is affected by the type of toner as shown is that the spectral reflectance of each toner is different depending on the wavelength of the anti-static light. The toner sensor 24 detects the amount of toner of each color by detecting the diffused light using the second light receiving element 203. Therefore, it is considered that the output value of the toner sensor 24 changes greatly when detecting (measuring) the amount of toner whose spectral reflectance increases depending on the wavelength of the anti-static light.

[0092] Figure 8 This is a graph showing the spectral reflectance of various toners with respect to the wavelength of irradiation light.

[0093] exist Figure 8 In FIG. 1 , curve Y, curve M, curve C, and curve K respectively represent the spectral reflectance of the yellow toner, the magenta toner, the cyan toner, and the black toner. Figure 8 In , wavelength P is the wavelength of light emitted by the light emitting element 201 of the toner sensor 24. Figure 8 In the illustrated example, the wavelength P of light emitted by the light emitting element 201 of the toner sensor 24 is approximately 650 to 670 nm.

[0094] like Figure 8 As shown in FIG. 1 , the spectral reflectance of each toner is different for the wavelength of the irradiated light. In addition, the spectral reflectance of each toner varies according to the wavelength of the irradiated light. Figure 2 As shown, in an image forming apparatus configured such that leakage light of static elimination light enters the toner sensor 24 from the static elimination 132, an influence corresponding to the wavelength of the static elimination light is generated for each type (color) of toner. In the image forming apparatus, it is assumed that the static elimination 132 emits static elimination light of a specific wavelength. In this case, the influence amount of static elimination light (leakage light) of a specific wavelength appearing in the output of the toner sensor 24 can be grasped for each type (color) of toner.

[0095] Next, a description will be given of correction of a target value (set value) used in density adjustment as image stabilization control according to the amount of influence of leakage light of static elimination light on various toners.

[0096] In order to suppress density deviation and stabilize the image, the digital multifunction machine 1 corrects the reference target value of density adjustment for each type (color) of toner according to the amount of influence caused by the leakage light of the anti-static light. As described above, the setting value (target value) of the image stabilization control such as density adjustment is set according to the sensor sensitivity of the toner sensor 24. The amount of influence of the anti-static light in the output of the toner sensor 24 also changes according to the sensor sensitivity. Therefore, the target value of the image stabilization control such as density adjustment is corrected by adding a correction value corresponding to the amount of influence of the anti-static light corresponding to the sensor sensitivity.

[0097] For example, in the system controller 5, the storage device 104 stores, for each toner, a target value obtained by correcting a reference target value corresponding to the sensor sensitivity with a correction value corresponding to the amount of influence of the static-eliminating light. In addition, the storage device 104 may store, for each toner, a reference target value and a correction value corresponding to the amount of influence of the static-eliminating light. The processor 101 of the system controller 5 performs image stabilization control using a target value obtained by correcting the reference target value with a correction value corresponding to the amount of influence of the static-eliminating light for each toner. Thus, the digital multifunction machine 1 can eliminate the influence of leakage light of the static-eliminating light and suppress concentration deviation in a specific toner to stabilize the image.

[0098] Fig. 9 1 is a diagram showing an example of a setting value (target value) of the image stabilization control according to the sensor sensitivity of the toner sensor 24 .

[0099] exist Fig. 9 In FIG. 1 , line La shows an example of a setting value when there is no influence of leakage light of anti-static light (a reference target value without correction corresponding to the influence of anti-static light). Line Lb shows an example of a setting value (a target value after correction) obtained by adding a correction value corresponding to the influence of leakage light of anti-static light. Fig. 9 In the example shown, if the sensor sensitivity is lower than the intersection of the line La and the line Lb, the target value of the image stabilization control is corrected to be smaller. In addition, if the sensor sensitivity is higher than the intersection of the line La and the line Lb, the target value of the image stabilization control is corrected to be larger.

[0100] As described above, the image forming apparatus according to the embodiment corrects the target value of the output value of the toner sensor used in the image stabilization control such as density adjustment according to the influence of the static elimination light. The image forming apparatus uses the set value corrected according to the influence of the static elimination light to perform image stabilization control such as density adjustment of each toner. As a result, the image forming apparatus can suppress the deviation of the output of the toner sensor caused by the leakage light from the static elimination, and can realize the image stabilization control with suppressed density deviation.

[0101] Next, correction of a target value (set value) used in image stabilization control according to the amount of influence of leakage light of static elimination light on various toners will be described.

[0102] According to the above Figure 8 In the example shown, the black toner (curve K) has a low spectral reflectivity regardless of the wavelength of the irradiated light. On the other hand, for the yellow toner (curve Y), magenta toner (curve M), and cyan toner (curve C), the wavelengths at which the spectral reflectivity increases and decreases are different. When the spectral reflectivity of the toner sensor 24 is low, the change in the output value caused by the static elimination light is small. If the change in the output value of the toner sensor 24 caused by the static elimination light is small, the leakage light of the static elimination light has almost no effect on the detection of the amount of toner adhesion. Therefore, for toners with low spectral reflectivity for the wavelength of the static elimination light, it is not necessary to perform corrections corresponding to the influence of the static elimination light. Therefore, the image forming device can also determine the toner that needs to be corrected for the amount of influence of the static elimination light based on the wavelength of the static elimination light emitted by the static elimination light 132.

[0103] exist Figure 8 In the example shown, when the wavelength of the irradiated light is 650nm, the spectral reflectance of the yellow and magenta toners is high, and the spectral reflectance of the cyan and black toners is low. When the wavelength of the anti-static light includes 650nm, if the detection object is a yellow or magenta toner, the output of the toner sensor 24 will be strongly affected by the anti-static light. When the wavelength of the anti-static light includes 650nm, if the detection object is a cyan or black toner, the output of the toner sensor 24 will hardly be affected by the anti-static light. When the wavelength of the anti-static light includes 650nm, the reference target value for the cyan or black toner is set to no correction, and the reference target value for the yellow and magenta toner is set to with correction. In this case, the image forming device adds a correction value corresponding to the amount of influence of the anti-static light to the reference target value for the yellow and magenta toners.

[0104] Fig.10 This is a diagram showing an example of setting the presence or absence of correction according to the amount of influence of the anti-static light according to the wavelength of the anti-static light for each type of toner.

[0105] Fig.10 Shown based on Figure 7 The spectral reflectance of various toners as shown in the figure is used to set the correction according to the influence of the static elimination light. Figure 7 In the example shown, if the spectral reflectance is about 10% or less, the reference target value of the image stabilization control does not need to be corrected. In this case, if the wavelength of the anti-static light is 400nm or less, the reference target value of the image stabilization control for the yellow, magenta, cyan and black toners does not need to be corrected (no correction). In addition, if the wavelength of the anti-static light is 400-480nm, the reference target value for the yellow and black toners does not need to be corrected. If the wavelength of the anti-static light is 480-570nm, the reference target value for the magenta and black toners does not need to be corrected. When the wavelength of the anti-static light is 570nm or more, the reference target value for the cyan and black toners does not need to be corrected.

[0106] If the presence or absence of correction is summarized for each wavelength, then Fig.10 As shown, a table can be obtained for determining whether or not there is a correction corresponding to the amount of influence of the anti-static light for each color of the toner corresponding to the wavelength of the anti-static light. For example, an image forming apparatus whose anti-static light has a wavelength of 570 nm or more is determined to be corrected for the reference target values ​​of yellow and magenta toners. In this case, the image forming apparatus stores the target values ​​obtained by correcting the reference target values ​​for yellow and magenta using the correction values ​​corresponding to the amount of influence of the anti-static light in the storage device 104.

[0107] As described above, the image forming apparatus involved in the embodiment determines the type (color) of the toner that should be corrected according to the amount of influence of the anti-static light based on the wavelength of the anti-static light. For the toner that is set to be corrected based on the wavelength of the anti-static light, the image forming apparatus stores the target value of the image stabilization control including the correction value in the memory. Thus, the image forming apparatus can specify whether correction corresponding to the influence of the anti-static light is required for each type of toner. As a result, the image forming apparatus can implement image stabilization control that removes the influence of the anti-static light with high precision without installing a component for shielding the leakage light of the anti-static light, etc.

[0108] Next, the updating of the correction value according to the influence amount of the static elimination light in the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment will be described.

[0109] The digital multifunction machine 1 as an image forming apparatus may also update the correction value corresponding to the influence of the static elimination light according to a predetermined update condition. In the digital multifunction machine 1, it is assumed that the influence of the static elimination light in the detection of the toner attachment amount using the toner sensor 24 changes due to the degree of use or the passage of time. This is caused by the change in the state of each part constituting the printer 2 according to the degree of use or the passage of time.

[0110] For example, it is assumed that the state of light caused by the static elimination light (leakage light) emitted by the static elimination 132 and incident on the toner sensor 24 changes according to the degree of use or the passage of time. As a specific example, it is assumed that if the printer 2 repeatedly performs image forming processing, the amount of light emitted by the static elimination 132 changes, or stains such as toner are generated in the static elimination 132. If the state of the static elimination light emitted by the static elimination 132 changes, the amount of influence of the static elimination light on the detection of the toner adhesion amount using the toner sensor 24 will also change.

[0111] It is assumed that the change in the influence of the anti-static light caused by the degree of use or the passage of time in the digital multifunction peripheral 1 is estimated in advance. If the change in the influence of the anti-static light is estimated, a correction value corresponding to the influence of the anti-static light under the update condition such as the degree of use or the passage of time can be set in advance. It is assumed that the storage device 104 stores in advance the correction value corresponding to the influence of the anti-static light under the specified update condition such as the degree of use or the passage of time. Therefore, when the degree of use or the passage of time reaches the update condition, the digital multifunction peripheral 1 updates the correction value for the target value of the image stabilization control to the correction value corresponding to the update condition.

[0112] As update conditions for updating the correction value for the target value of the image stabilization control, the number of recording media on which printing is performed (print count), the driving time or elapsed time of a specific unit, and the like can be set.

[0113] For example, in the case where it is assumed that the state of the anti-static light changes due to repeated printing, the digital multifunction machine 1 sets a predetermined number of prints as an update condition for the correction value. In this case, the system controller 5 stores in advance in the storage device 104 a correction value corresponding to the amount of influence of the anti-static light when the predetermined number of prints set as the update condition is executed. The processor 101 of the system controller 5 saves the cumulative value of the number of prints (cumulative number of prints) in the storage device 104 each time printing is executed. When the cumulative number of prints reaches the predetermined number of prints of the update condition, the processor 101 updates the target value obtained by correcting the reference target value using the correction value corresponding to the predetermined number of prints stored in the storage device 104.

[0114] In addition, if it is assumed that the state of the static-eliminating light changes according to the driving time (accumulated driving time) of a specific unit, the digital multifunction peripheral 1 may set the driving time as the updating condition of the correction value. The driving time as the updating condition of the correction value may be set to the driving time of the photosensitive drum 122, the driving time of the developer 110, or the driving time of the transfer belt 21.

[0115] For example, when setting an update condition for the drive time of the photosensitive drum 122, the system controller 5 stores a correction value corresponding to the prescribed drive time as the update condition in the storage device 104. The processor 101 of the system controller 5 stores the cumulative value of the drive time of the photosensitive drum 122 in the storage device 104 each time the photosensitive drum 122 is driven. When the cumulative value of the drive time of the photosensitive drum 122 reaches the prescribed drive time as the update condition, the processor 101 updates the target value obtained by correcting the reference target value with the correction value corresponding to the prescribed drive time stored in the storage device 104. It should be noted that the correction value can be updated for the drive time of the developer 110 or the drive time of the transfer belt 21 in the same manner as the drive time of the photosensitive drum 122.

[0116] Furthermore, in the case where it is assumed that the state of the anti-static light changes according to the elapsed time, the digital multifunction machine 1 may set the elapsed time as an update condition of the correction value. For the elapsed time as the update condition of the correction value, the emission time of the anti-static light of the anti-static light 132 or the like can be set. For example, in the case where the update condition is set for the emission time of the anti-static light, the system controller 5 stores the correction value corresponding to the prescribed elapsed time as the update condition in the storage device 104. The processor 101 of the system controller 5 stores the cumulative value of the emission time of the anti-static light in the storage device 104 each time the anti-static light is emitted by the anti-static light 132. When the cumulative value of the emission time of the anti-static light reaches the prescribed elapsed time as the update condition, the processor 101 updates the target value obtained by correcting the reference target value using the correction value corresponding to the prescribed elapsed time stored in the storage device 104.

[0117] Fig.11 This is a flowchart for explaining a process of updating a correction value for a target value of image stabilization control in the digital multifunction peripheral 1 as the image forming apparatus according to the embodiment.

[0118] The processor 101 of the system controller 5 in the digital multifunction peripheral 1 accumulates log information indicating the degree of use or elapsed time corresponding to the execution of the image forming process in the storage device 104 (ACT 111). For example, when a predetermined number of prints is set as an update condition, the processor 101 stores log information including the accumulated number of prints in the storage device 104. In addition, when the drive time (or elapsed time) of a specific unit is set as an update condition, the processor 101 stores log information including the accumulated drive time (or elapsed time) of the specific unit in the storage device 104.

[0119] The processor 101 determines whether the log information stored in the storage device 104 meets the update condition of the correction value for the target value of the image stabilization control (ACT 112). For example, when a specified number of prints is set as the update condition, the processor 101 determines whether the accumulated number of prints stored in the storage device 104 reaches the specified number of prints as the update condition. When a specified driving time is set as the update condition, the processor 101 determines whether the accumulated driving time of the specific unit reaches the specified driving time as the update condition.

[0120] When the log information stored in the storage device 104 does not meet the update condition (ACT 112 , No), the processor 101 returns to the above-mentioned ACT 111 to continue accumulating the log information.

[0121] When the information indicated by the log information stored in the storage device 104 reaches the update condition (ACT112, YES), the processor 101 updates the correction value for the reference target value of the image stabilization control to the correction value corresponding to the update condition (ACT113). When updating the correction value, the processor 101 updates the target value of each toner to a target value obtained by correcting the reference target value with the correction value corresponding to the update condition. For example, when the accumulated number of prints reaches the prescribed number of prints as the update condition, the processor 101 updates the correction value for the reference target value to the correction value corresponding to the prescribed number of prints as the update condition. When the accumulated drive time of a specific unit reaches the prescribed drive time as the update condition, the processor 101 updates the correction value for the reference target value to the correction value corresponding to the prescribed drive time.

[0122] As described in detail above, the image forming apparatus according to the embodiment includes a toner sensor that outputs a signal corresponding to the amount of toner attached to the transfer belt. The image forming apparatus stores a target value including a correction value for image stabilization control for stabilizing an image in a memory for each type of toner. The image forming apparatus performs image stabilization control for adjusting a set value for image forming processing so that an output value of the toner sensor becomes a target value including the correction value.

[0123] Thus, the image forming apparatus according to the embodiment can stabilize the image without installing a light shielding wall for blocking the anti-static light emitted by the anti-static eliminator. In other words, even if the image forming apparatus according to the embodiment is configured such that a part of the anti-static light from the anti-static eliminator is incident on the toner sensor in order to achieve miniaturization and cost reduction, the image can be stabilized without adding components.

[0124] Furthermore, the image forming apparatus according to the embodiment stores in a memory log information indicating the degree of use, elapsed time, etc. The image forming apparatus updates a correction value for a target value of image stabilization control for stabilizing an image based on the log information stored in the memory.

[0125] Thus, when the state of the static-eliminating light changes depending on the accumulated number of prints, the driving time of a specific unit, or the elapsed time, the image forming apparatus can update the correction value to a value suitable for the state.

[0126] Although several embodiments are described, these embodiments are only presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and their variations are included in the scope and purpose of the invention, and are also included in the invention described in the claims and their equivalents.

[0127] Next, an image forming apparatus according to an embodiment will be described. [1]

[0129] The image forming device has:

[0130] Photoreceptor;

[0131] a static eliminator for emitting static eliminator light to irradiate the photosensitive body;

[0132] a charger for charging the photoreceptor which has been de-electrified by the de-electrifier;

[0133] an exposure device for forming an electrostatic latent image on the photosensitive body charged by the charger;

[0134] a developer for supplying toner to the photosensitive body on which the electrostatic latent image is formed by the exposure device;

[0135] a toner sensor that outputs a signal corresponding to the amount of toner deposited on the image bearing member to which the toner is transferred from the photosensitive member;

[0136] a memory storing target values ​​including correction values ​​for image stabilization control for stabilizing an image for each type of toner; and

[0137] The processor executes image stabilization control that performs setting so that the output value of the toner sensor becomes a target value including the correction value for each type of toner. [2]

[0139] In the image forming apparatus described in [1],

[0140] The correction value is a correction amount for each type of toner according to the wavelength of the static elimination light emitted by the static elimination device. [3]

[0142] In the image forming apparatus described in [2],

[0143] The correction value is a correction amount according to the sensor sensitivity of the toner sensor. [4]

[0145] In the image forming apparatus described in [2],

[0146] The toner sensor includes a light emitting element for irradiating light to a detection surface, a first light receiving element for receiving regular reflected light on the detection surface, and a second light receiving element for receiving diffused light on the detection surface.

[0147] The memory stores, as the correction value, a correction amount for a toner of a specific color selected based on a spectral reflectance of each color of the toner with respect to a wavelength of the neutralization light. [5]

[0149] In the image forming apparatus described in [4],

[0150] The static eliminator emits static eliminator light with a wavelength of 570 nm or more.

[0151] The memory stores a correction amount for a yellow toner and a correction amount for a magenta toner as the correction values. [6]

[0153] In the image forming apparatus described in [1],

[0154] The processor updates the correction value stored in the memory according to the number of recording media to which the toner image is transferred from the image bearing body by the image forming apparatus. [7]

[0156] In the image forming apparatus described in [1],

[0157] The processor updates the correction value stored in the memory according to the driving time of the photosensitive body. [8]

[0159] In the image forming apparatus described in [1],

[0160] The processor updates the correction value stored in the memory according to the driving time of the developer. [9]

[0162] In the image forming apparatus described in [1],

[0163] The processor updates the correction value stored in the memory according to the driving time of the transfer body.

[10]

[0165] In the image forming apparatus described in [1],

[0166] The processor updates the correction value stored in the memory according to the light emission time of the static eliminator emitting the static eliminator light.

Claims

1. An image forming device comprising: Photoreceptor; a static eliminator for emitting static eliminator light to irradiate the photosensitive body; a charger for charging the photoreceptor which has been de-electrified by the de-electrifier; an exposure device for forming an electrostatic latent image on the photosensitive body charged by the charger; a developer for supplying toner to the photosensitive body on which the electrostatic latent image is formed by the exposure device; a toner sensor that outputs a signal corresponding to the amount of toner attached to the image bearing member to which the toner is transferred from the photosensitive member; a memory storing target values ​​including correction values ​​for image stabilization control for stabilizing an image for each type of toner; as well as The processor executes image stabilization control that performs setting so that the output value of the toner sensor becomes the target value including the correction value for each type of toner.

2. The image forming apparatus according to claim 1, wherein: The correction value is a correction amount for each type of toner according to the wavelength of the static elimination light emitted by the static elimination device.

3. The image forming apparatus according to claim 2, wherein: The correction value is a correction amount according to the sensor sensitivity of the toner sensor.

4. The image forming apparatus according to claim 2, wherein: The toner sensor includes a light emitting element for irradiating light to a detection surface, a first light receiving element for receiving regular reflected light on the detection surface, and a second light receiving element for receiving diffused light on the detection surface. The memory stores, as the correction value, a correction amount for a toner of a specific color selected based on a spectral reflectance of each color of the toner with respect to a wavelength of the neutralization light.

5. The image forming apparatus according to claim 4, wherein: The static eliminator emits static eliminator light with a wavelength of 570 nm or more. The memory stores a correction amount for a yellow toner and a correction amount for a magenta toner as the correction values.

Images