JP4874717B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly to an image forming apparatus having an optical sensor unit.

  Conventionally, various sensors from an inexpensive one to an expensive one have been incorporated in an image forming apparatus. For example, as an optical sensor combining a light emitting element and a light receiving element, there are a document paper size detection sensor in a scanner system, a density sensor in a drum periphery system, and a positional deviation detection sensor for detecting positional deviation. Further, there are a feedback sensor that detects the speed of the intermediate transfer belt in the transfer system, and a paper feed sensor, a registration sensor, and a paper type detection sensor that determines the type of paper in the paper transport system. In addition, the device main body is provided with a memory for storing information related to the optical sensor such as operation history and light emission output, which is lifetime determination information of the optical sensor, and the device main body is based on such information. The life of the optical sensor is determined or the light emission output is adjusted by the control device provided in the above.

In recent years, image forming apparatuses such as copiers and printers have been recycled from the viewpoint of global environmental conservation, and the above-described components such as optical sensors have been reused and recycled. Therefore, if the collected optical sensor quality condition and the operation history, which is life judgment information, satisfy certain conditions, the optical sensor removed from the apparatus main body is incorporated into another apparatus main body as a reusable one. This reduces resource and energy consumption and reduces manufacturing costs. In addition, it is possible to reduce the amount of waste by classifying other materials and recycling them as recycled materials.
In particular, among optical sensors, particularly expensive ones include a density sensor and a positional deviation detection sensor. As an image forming apparatus using such a sensor, as shown in FIGS. 2 and 3, an image density detection sensor unit (P sensor) 310 has a density sensor 311 or a position shift detection sensor as an expensive optical sensor. There are some in which a plurality of 312 are mounted. When the P sensor is reused in such an image forming apparatus, an effect of suppressing the manufacturing cost of the image forming apparatus can be further expected as compared with a case where a new P sensor is incorporated.

  In addition, an optical sensor provided in the apparatus main body may fail or reach the end of its life, or for other reasons, an optical sensor that has failed or has reached the end of its life may be replaced. In this case, since there is a variation in the characteristic value such as the light emission output for each individual optical sensor, it is necessary to rewrite the information on the optical sensor in the memory of the device body from the information on the optical sensor before replacement to the information on the optical sensor after replacement. There is.

JP 2004-341142 A

In general, when managing information relating to an optical sensor removed from the apparatus main body, information relating to the optical sensor removed from the apparatus main body is read from a memory provided in the apparatus main body and recorded on a sheet or a recording device. The optical sensor removed from the apparatus main body and the information related to the optical sensor recorded on the paper or the recording device must be managed in association with each other so that the information of the optical sensor can be understood. If the optical sensor and the information related to the recorded optical sensor are not managed so as to be associated with each other, the association between the optical sensor and the recorded optical sensor information is not correct, and the optical sensor information is There is a problem that you don't understand.
For example, the information regarding the optical sensor removed from the apparatus main body may include reuse determination information used for determining whether the optical sensor can be reused. In this case, when performing the reuse possibility determination of the optical sensor removed from the apparatus main body, the problem described above, reuse availability judgment information of the light sensor is not the kind of problem know occur.

The present invention has been made in view of the above problems, and an object is to provide an image forming apparatus provided with an optical sensor body information about itself known.

In order to achieve the above object, the invention of claim 1 is characterized in that an image forming means for forming an image on a recording medium and light received from the light emitting means is received by the light receiving means through the irradiation object. An image forming apparatus including an optical detection unit that detects an optical characteristic of the irradiation target and a housing that houses the optical detection unit, and an optical sensor unit that is replaceable with respect to the apparatus main body. Information storage means is provided in the housing, and has processing means for performing at least one of information writing processing and reading processing on the information storage means. Life determination information used for life determination is included, and the life determination information is a time shorter than a life time of the optical detection unit by a predetermined time, and the information includes the optical in the apparatus main body. Replacement determination information that is information that the apparatus body can determine that the sensor unit has been replaced is included, and the light emission output value of the light emitting means at the initial time is used as the replacement determination information. The optical detection unit is set to a unique value that cannot be obtained in a normal use state.
Further, the invention of claim 2, the image forming apparatus according to claim 1, in the upper SL information, is characterized in that includes characteristic value information showing characteristic values of the optical detection unit.
Further, the invention of claim 3, the image forming apparatus according to claim 2, in the upper Symbol characteristic value information, is characterized in that includes an initial state characteristic value information of the optical detector initial time.
The invention of claim 4 is the image forming apparatus according to claim 2 or 3, the upper Symbol characteristic value information includes cleaning after characteristic value information is a characteristic value of the optical detection unit after being cleaned It is characterized by this.
The invention of claim 5 is the image forming apparatus according to claim 2, 3 or 4, the upper Symbol characteristic value information and is characterized to include individual identification information of the optical sensor unit.
The invention of claim 6 is the image forming apparatus according to claim 2, 3, 4 or 5, the upper Symbol characteristic value information, characterized in that contains reuse frequency information of the optical sensor unit is there.
The invention of claim 7 is reflected in the image forming apparatus according to claim 2, 3, 4, 5 or 6, the upper Symbol optical detection unit, the irradiation light irradiated from the light emitting means is irradiated object The reflected light is received by the light receiving means.
The invention of claim 8 is the image forming apparatus according to claim 2, 3, 4, 5 or 6, the upper Symbol optical detection unit, transmit the irradiation light irradiated from the light emitting means is irradiated object The transmitted light at this time is received by the light receiving means.
According to a ninth aspect of the present invention, in the image forming apparatus according to the seventh aspect, the optical detection unit detects an image density.
According to a tenth aspect of the present invention, in the image forming apparatus according to the eighth aspect, the optical detection unit detects the type of the recording medium.

  In the present invention, information storage means for storing information in the optical sensor unit is provided. Thereby, for example, information relating to the optical sensor unit can be stored in the information storage unit. Therefore, since the optical sensor unit and the information storage means are integrated, even when the optical sensor unit is detached from the apparatus main body, there is an excellent effect that information about the optical sensor unit can be understood from the information storage means.

  An embodiment of the present invention will be described with reference to the drawings. The present embodiment is an application example to a tandem type full-color electrophotographic copying machine (hereinafter simply referred to as “copying machine”) as an image forming apparatus.

  First, the configuration of the entire copying machine of this embodiment will be described. FIG. 4 is a schematic configuration diagram showing the entire copying machine according to the present embodiment. The copying machine includes a copying machine main body 100 that forms an image, a paper feeding device 200 on which the copying machine main body 100 is mounted and that supplies transfer paper 5 as a recording material to the copying machine main body 100, and a copying machine main body. A scanner 300 that is mounted on 100 and reads a document image, and an automatic document feeder (ADF) 400 that is mounted on the scanner 300 are provided. The copying machine main body 100 is provided with a manual feed tray 6 for manually feeding the transfer paper 5 and a paper discharge tray 7 for discharging the transfer paper 5 on which an image has been formed.

  FIG. 5 is an enlarged view showing the configuration of the copying machine main body 100. The copying machine main body 100 is provided with an endless belt-like intermediate transfer belt 10 which is an intermediate transfer member. The intermediate transfer belt 10 is made of polyimide, which is a material having excellent mechanical characteristics in order to prevent misalignment due to belt elongation, and has high image quality and high stability, that is, a temperature and humidity environment. Carbon is dispersed as a resistance adjusting agent in order to always obtain stable transfer performance regardless of the resistance. Therefore, the belt color is black. The intermediate transfer belt 10 is driven to rotate clockwise in FIG. 5 while being stretched around the three support rollers 14, 15, and 16.

  As shown in FIG. 5, of the support rollers 14, 15, 16, the belt stretched portion between the first support roller 14 and the second support roller 15 has yellow (Y), cyan (C), magenta Four image forming units 18Y, 18C, 18M, and 18K of (M) and black (K) are arranged side by side. A P sensor 310 for detecting the density of the patch formed on the intermediate transfer belt is attached to the belt stretch portion between the first support roller 14 and the third support roller 16. The P sensor 311 is connected to the cable of the apparatus main body via a connector. When the P sensor 311 is replaced, the connector is removed from the P sensor 311 and the connector is attached to the P sensor. . Here, as a sensor used for such patch density detection, a reflection type sensor in which an LED (light emitting diode) as a light emitting element and a PD (photodiode) or PTr (phototransistor) as a light receiving element is generally known. It has been. The configuration of the sensor includes (1) a type that detects only specular reflection light shown in FIG. 6, (2) a type that detects only diffuse reflection light shown in FIG. 7, and (3) a specular reflection light shown in FIG. There are various types such as a type that detects both diffuse reflection light and (4) a type in which a beam splitter is provided in the light emitting path / light receiving path shown in FIG.

As shown in FIG. 1, two density sensors 311 are provided in the longitudinal direction of the photosensitive member 20, the front side sensor is provided for detecting a color toner pattern, and the back side sensor is provided for detecting a black toner pattern. Yes. The black toner pattern detection sensor is a regular reflection type sensor shown in FIG. 6, and the color toner pattern detection sensor is a regular reflection + diffuse reflection type sensor shown in FIG. Both of these concentration sensors 311 include a GaAs infrared light emitting diode having a peak light emission wavelength: λp = 950 [nm] for an LED as a light emitting element, and a Si phototransistor having a peak light receiving sensitivity: 800 [nm] for a light receiving element. I use it. In addition, the distance (detection distance) between the density sensor 311 and the belt as the detection target surface is set to 5 [mm].
Further, on the substrate of the P sensor 310, in addition to the density sensor 311, a misregistration detection sensor 312 for measuring the misregistration amount of each color of CMYK is on the front and center. The memory 313 according to the present invention is further provided at three locations in the back. In the memory 313, data shown in Table 1 can be stored as storage information. Note that the information stored in the memory 313 is not limited to the information shown in Table 1, but the lifetime of the density sensor 311 and the remaining usage time may be stored.

  An exposure device 21 is provided above the image forming units 18Y, 18C, 18M, and 18K as shown in FIG. The exposure apparatus 21 emits writing light by driving a semiconductor laser (not shown) by a laser control unit (not shown) based on the image information of the document read by the scanner 300, and each image forming unit. This is for forming an electrostatic latent image on the photoconductive drums 20Y, 20C, 20M, and 20K as image carriers provided on 18Y, 18C, 18M, and 18K. Here, the emission of the writing light is not limited to the laser, but may be an LED, for example.

  The configuration of the image forming units 18Y, 18C, 18M, and 18K will be described. In the following description, the image forming unit 18K that forms a black toner image will be described as an example, but the other image forming units 18Y, 18C, and 18M have the same configuration. Here, FIG. 10 is an enlarged view showing a configuration of two adjacent image forming units 18M and 18K. In addition, in the code | symbol in a figure, the symbol of "M" and "K" which shows distinction of a color is abbreviate | omitted, and a symbol is abbreviate | omitted suitably also in the following description.

  In the image forming unit 18, a charging device 60, a developing device 61, a photoconductor cleaning device 63, and a charge removal device 64 are provided around the photoconductor drum 20. Further, a primary transfer device 62 is provided at a position facing the photosensitive drum 20 via the intermediate transfer belt 10.

  The charging device 60 is of a non-contact charging type employing a charging roller, and uniformly charges the surface of the photosensitive drum 20 by applying a voltage with a predetermined gap in the photosensitive drum 20. As the charging device 60, a non-contact charging type using a non-contact scorotron charger or the like can be used.

  The developing device 61 uses a two-component developer composed of a magnetic carrier and a nonmagnetic toner. The developing device 61 can be broadly divided into a stirring unit 66 and a developing unit 67 provided in the developing case 70. In the agitating unit 66, a two-component developer (hereinafter simply referred to as “developer”) is conveyed while being agitated and supplied onto a developing sleeve 65, which will be described later, as a developer carrying member. The stirring unit 66 is provided with two parallel screws 68, and a partition plate is provided between the two screws 68 for partitioning so that both ends communicate with each other. Further, a toner concentration sensor 71 for detecting the toner concentration of the developer in the developing device 61 is attached to the developing case 70. On the other hand, in the developing unit 67, the toner of the developer attached to the developing sleeve 65 is transferred to the photosensitive drum 20. The developing portion 67 is provided with a developing sleeve 65 that faces the photosensitive drum 20 through the opening of the developing case 70, and a magnet (not shown) is fixedly disposed in the developing sleeve 65. Further, a doctor blade 73 is provided so that the tip approaches the developing sleeve 65.

  In the developing device 61, the developer is conveyed and circulated while being stirred by two screws 68, and is supplied to the developing sleeve 65. The developer supplied to the developing sleeve 65 is pumped and held by a magnet. The developer pumped up by the developing sleeve 65 is conveyed along with the rotation of the developing sleeve 65 and is regulated to an appropriate amount by the doctor blade 73. The regulated developer is returned to the stirring unit 66. Thus, the developer transported to the developing area facing the photosensitive drum 20 is brought into a spiked state by the magnet and forms a magnetic brush. In the developing region, a developing electric field for moving the toner in the developer to the electrostatic latent image portion on the photosensitive drum 20 is formed by the developing bias applied to the developing sleeve 65. As a result, the toner in the developer is transferred to the electrostatic latent image portion on the photosensitive drum 20, and the electrostatic latent image on the photosensitive drum 20 is visualized to form a toner image. The developer that has passed through the developing region is transported to a portion where the magnetic force of the magnet is weak, and thus is separated from the developing sleeve 65 and returned to the stirring unit 66. When the toner concentration in the stirring unit 66 becomes light by repeating such an operation, the toner concentration sensor 71 detects this, and the toner is supplied to the stirring unit 66 based on the detection result.

  The primary transfer device 62 employs a transfer roller and is installed so as to be pressed against the photosensitive drum 20 with the intermediate transfer belt 10 interposed therebetween. The primary transfer device 62 may not be a roller shape, but may be a conductive brush shape, a non-contact corona charger, or the like.

  The photoconductor cleaning device 63 includes a cleaning blade 75 made of, for example, polyurethane rubber, which is disposed so that the front end is pressed against the photoconductor drum 20. In the present embodiment, a conductive fur brush 76 that contacts the photosensitive drum 20 is used in combination to improve the cleaning performance. The toner removed from the photoconductor drum 20 by the cleaning blade 75 and the fur brush 76 is accommodated in the photoconductor cleaning device 63.

  The static eliminator 64 is composed of a static elimination lamp, and irradiates light to initialize the surface potential of the photosensitive drum 20.

  The image forming unit 18 is provided with a potential sensor 320 corresponding to each photosensitive drum 20. The potential sensor 320 is provided so as to face the photosensitive drum 20 and detects the potential of the surface of the photosensitive drum 20.

  Specific settings of the image forming unit 18 will be described. The diameter of the photosensitive drum 20 is 60 [mm], and the photosensitive drum 20 is driven at a linear speed of 282 [mm / s]. The developing sleeve 65 has a diameter of 25 [mm], and the developing sleeve 65 is driven at a linear speed of 564 [mm / s]. In addition, the charge amount of the toner in the developer supplied to the development region is preferably in the range of about −10 to −30 [μC / g]. The development gap, which is the gap between the photosensitive drum 20 and the development sleeve 65, can be set in the range of 0.5 to 0.3 [mm], and the development efficiency can be improved by reducing the value. It is. Further, the thickness of the photosensitive layer of the photosensitive drum 20 is 30 [μm], the beam spot diameter of the optical system of the exposure device 21 is 50 × 60 [μm], and the amount of light is about 0.47 [mW]. is there. As an example, the surface of the photosensitive drum 20 is uniformly charged to −700 [V] by the charging device 60, and the potential of the electrostatic latent image portion irradiated with the laser by the exposure device 21 is −120 [V]. . On the other hand, the developing bias voltage is set to -470 [V], and a developing potential of 350 [V] is secured. Such process conditions are appropriately changed according to the result of the potential control.

  In the image forming unit 18 having the above configuration, first, the surface of the photosensitive drum 20 is uniformly charged by the charging device 60 as the photosensitive drum 20 rotates. Next, based on the image information read by the scanner 300, the exposure light is irradiated from the exposure device 21 to form an electrostatic latent image on the photosensitive drum 20. Thereafter, the electrostatic latent image is visualized by the developing device 61 to form a toner image. This toner image is primarily transferred onto the intermediate transfer belt 10 by the primary transfer device 62. The transfer residual toner remaining on the surface of the photosensitive drum 20 after the primary transfer is removed by the photosensitive member cleaning device 63, and thereafter, the surface of the photosensitive drum 20 is discharged by the static eliminating device 64, and the next image formation is performed. Provided.

  Next, as shown in FIG. 5, a secondary transfer roller 24, which is a secondary transfer device, is provided at a position facing the third support roller 16 among the support rollers. When the toner image on the intermediate transfer belt 10 is secondarily transferred onto the transfer paper 5, the secondary transfer roller 24 is pressed against the portion of the intermediate transfer belt 10 wound around the third support roller 16. Next transfer is performed. The secondary transfer device may not be configured using the secondary transfer roller 24 but may be configured using, for example, a transfer belt or a non-contact transfer charger. The secondary transfer roller 24 is in contact with a roller cleaning unit 91 that cleans toner adhering to the secondary transfer roller 24.

  Further, an endless belt-like transport belt 22 is stretched between the two rollers 23a and 23b on the downstream side of the secondary transfer roller 24 in the transport direction of the transfer paper 5. Further, a fixing device 25 for fixing the toner image transferred onto the transfer paper 5 is provided further downstream in the transport direction. The fixing device 25 has a configuration in which a pressure roller 27 is pressed against a heating roller 26. Further, a belt cleaning device 17 is provided at a position facing the second support roller 15 among the support rollers of the intermediate transfer belt 10. The belt cleaning device 17 is for removing residual toner remaining on the intermediate transfer belt 10 after the toner image on the intermediate transfer belt 10 is transferred to the transfer paper 5.

  Further, as shown in FIG. 4, the copying machine main body 100 is provided with a conveyance path 48 that guides the transfer paper 5 fed from the paper feeding device 200 to the paper discharge tray 7 via the secondary transfer roller 24. Along the conveyance path 48, a conveyance roller 49a, a registration roller 49b, a discharge roller 56, and the like are provided. A switching claw 55 is provided on the downstream side of the transport path 48 to switch the transport direction of the transfer paper 5 after transfer to the paper discharge tray 7 or the paper reversing device 93. The paper reversing device 93 reverses the transfer paper 5 and sends it again toward the secondary transfer roller 24. Further, the copying machine main body 100 is provided with a manual feed path 53 that joins from the manual feed tray 6 to the transport path 48, and the transfer paper 5 set in the manual feed tray 6 is located upstream of the manual feed path 53. A sheet feeding roller 50 and a separation roller 51 are provided for feeding sheets one by one.

  The paper feeding device 200 includes a plurality of paper feeding cassettes 44 that store the transfer paper 5, a paper feeding roller 42 and a separation roller 45 that feed the transfer papers stored in these paper feeding cassettes 44 one by one, and the fed transfer paper Is composed of a transport roller 47 that transports the paper along the paper feed path 46. The paper feed path 46 is connected to the conveyance path 48 of the copying machine main body 100.

  The scanner 300 will be briefly described with reference to FIG. In the scanner 300, first and second traveling bodies 33 and 34 mounted with a document illumination light source and a mirror reciprocate in order to read and scan a document (not shown) placed on the contact glass 31. To do. The image information scanned by the traveling bodies 33 and 34 is collected by the imaging lens 35 on the imaging surface of the reading sensor 36 installed behind the imaging lens 35 and read by the reading sensor 36 as an image signal.

  FIG. 11 is a block diagram showing the electrical connection of each part provided in the copying machine of the present embodiment. As shown in FIG. 11, the copying machine of the present embodiment is provided with a main control unit 500 having a computer configuration, and the main control unit 500 drives and controls each unit. The main control unit 500 includes a ROM (Read Only Memory) 503 that stores in advance fixed data such as a computer program via a bus line 502 in a CPU (Central Processing Unit) 501 that executes various calculations and drive control of each unit. A RAM (Random Access Memory) 504 that functions as a work area for storing various data in a rewritable manner is connected.

  The ROM 503 stores a conversion table (not shown) that stores information related to conversion of the output value of the P sensor 310 into the toner adhesion amount per unit area.

  Connected to the main controller 500 are each part of the copying machine main body 100, a paper feeding device 200, a scanner 300, and an automatic document feeder 400. Here, the P sensor 310 and the potential sensor 320 of the copying machine main body 100 send the detected information to the main control unit 500.

  Next, the operation of the copier of this embodiment will be described. When copying a document using the copying machine having the above configuration, first, the document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 31 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it. Thereafter, when the user presses a start switch (not shown), when the document is set on the automatic document feeder 400, the document is conveyed onto the contact glass 31. Then, the scanner 300 is driven and the first traveling body 33 and the second traveling body 34 start traveling. Thereby, the light from the first traveling body 33 is reflected by the document on the contact glass 31, and the reflected light is reflected by the mirror of the second traveling body 34 and guided to the reading sensor 36 through the imaging lens 35. . In this way, the image information of the original is read.

  When the start switch is pressed by the user, a drive motor (not shown) is driven, and one of the support rollers 14, 15, 16 is rotationally driven to rotate the intermediate transfer belt 10. At the same time, the photosensitive drums 20Y, 20C, 20M, and 20K of the image forming units 18Y, 18C, 18M, and 18K are also rotationally driven. Thereafter, based on the image information read by the reading sensor 36 of the scanner 300, writing light is emitted from the exposure device 21 onto the photosensitive drums 20Y, 20C, 20M, and 20K of the image forming units 18Y, 18C, 18M, and 18K. Each is irradiated. As a result, electrostatic latent images are formed on the respective photosensitive drums 20Y, 20C, 20M, and 20K, and are visualized by the developing devices 61Y, 61C, 61M, and 61K. Then, yellow (Y), cyan (C), magenta (M), and black (K) toner images are formed on the photosensitive drums 20Y, 20C, 20M, and 20K, respectively.

  Each color toner image formed in this way is primarily transferred by the primary transfer devices 62Y, 62C, 62M, and 62K so as to sequentially overlap each other on the intermediate transfer belt 10. As a result, a composite toner image in which the toner images of the respective colors overlap is formed on the intermediate transfer belt 10. The transfer residual toner remaining on the intermediate transfer belt 10 after the secondary transfer is removed by the belt cleaning device 17.

  When the user presses the start switch, the paper feed roller 42 of the paper feed device 200 corresponding to the transfer paper 5 selected by the user rotates, and the transfer paper 5 is sent out from one of the paper feed cassettes 44. The transferred transfer paper 5 is separated into one sheet by the separation roller 45 and enters the paper feed path 46, and is conveyed by the conveyance roller 47 to the conveyance path 48 in the copying machine main body 100. The transfer sheet 5 thus transported is stopped when it abuts against the registration roller 49b.

  The registration roller 49 b starts to rotate in accordance with the timing at which the composite toner image formed on the intermediate transfer belt 10 as described above is conveyed to the secondary transfer unit facing the secondary transfer roller 24. The transfer paper 5 sent out by the registration roller 49b is sent between the intermediate transfer belt 10 and the secondary transfer roller 24, and the secondary transfer roller 24 causes the composite toner image on the intermediate transfer belt 10 to be transferred onto the transfer paper 5. Secondary transfer is performed. Thereafter, the transfer paper 5 is conveyed to the fixing device 25 while being attracted to the secondary transfer roller 24, and heat and pressure are applied by the fixing device 25 to perform a toner image fixing process. The transfer paper 5 that has passed through the fixing device 25 is discharged to the paper discharge tray 7 by the discharge roller 56 and stacked. When image formation is performed also on the back surface of the surface on which the toner image is fixed, the transfer paper 5 that has passed through the fixing device 25 is switched by the switching claw 55 and sent to the paper reversing device 93. The transfer paper 5 is then reversed and guided to the secondary transfer roller 24 again.

Next, control for keeping the image density stable based on the computer program by the CPU 501 of the present embodiment will be described. The unstable image density may be caused by the life of a density sensor 311 described later. For example, when an LED is used as the light emitting element of the concentration sensor 311, the LED has a property that a lattice defect increases due to energization and the luminous intensity gradually decreases. FIG. 12 shows the data of the luminous intensity remaining rate with respect to the LED operation time (= light emission time). Thus, the decrease rate of the light amount of the LED is higher as the current value is larger, and the deterioration progresses as the ambient temperature is higher. You can see that the speed is accelerated. For this reason, the light intensity of the light emitting element decreases with time, so that it is impossible to stably detect the image density. Therefore, when the image density becomes unstable due to the life of the density sensor 311, a stable image density can be obtained by replacing the density sensor 311 with a new one.
In addition, the cause of the unstable image density is not only the life of the density sensor 311 but also the stain of the density sensor 311. This is because the density sensor 311 detects the patch density of the density detection toner patch created on the image carrier that is the detection target surface, and therefore, the toner that is the detection target is a statically charged powder. When the toner floating around the density sensor 311 adheres to the density sensor 311, the density sensor 311 becomes dirty. For this reason, even if the image density becomes unstable, if the density sensor 311 is contaminated, it is possible to obtain a stable image density again by cleaning the density sensor 311. For this reason, if the density sensor 311 is easily replaced simply because the image density becomes unstable, waste is generated from the viewpoint of recycling.

  For this reason, it is necessary to determine whether or not the density sensor 311 is dirty. As a method for determining the contamination of the density sensor 311, there is a method described in the above-mentioned Patent Publication 1. In the image forming apparatus described in Japanese Patent Application Laid-Open No. 2005-228867, if the output voltage Vp of the sensor that receives the reflected light from the surface of the intermediate transfer belt is within a predetermined range, it is determined as normal, and if it falls below this range, the sensor is dirty. It is determined. In this method, a contamination determination threshold is provided on the output voltage side of the light receiving element. In this way, providing a threshold value for contamination determination on the light receiving element side output means that there is a reference voltage that is determined in advance in the control for the light receiving element output voltage that is a comparison determination target for determining contamination. It is easy to make a dirt determination, such as being impossible if the difference from the reference voltage exceeds a certain value.

  However, if the device is made ready for use by simply issuing a warning to the operation unit or the like when it falls below the determination threshold, the density detection error is outside the allowable range, so the image density is There is a high possibility that the concentration will be different from the target. Therefore, in this embodiment, in order to avoid this, when the output voltage decreases due to the contamination of the density sensor 311, a method of preventing a decrease in density detection error by immediately adjusting the light amount is used. In this case, since the light emission output side adjustment is performed so that the light reception output of the density sensor 311 is always constant, the contamination determination may be performed using the characteristic value on the light emission output side, that is, the current value of the LED or a value corresponding thereto. .

  Further, the light emitting element and the light receiving element constituting the density sensor 311 have variations in output values for each element. Here, in order to clarify how much the output of the element varies, evaluation is performed by measuring the output by the following method for each of several lots (1 lot = 197 pieces) of LED as a light emitting element and PTr as a light receiving element. went.

[Light emitting element side]
Using the sensor head shown in FIG. 6, Vcc = 5 [V], LED current value If = 14.2 [mA], and the light receiving element fixed. The photocurrent IL of the light receiving element when irradiated is measured, and the magnitude of the light emission output is determined.
[Light receiving element side]
Using the sensor head shown in FIG. 6, Vcc = 5 [V], LED current value If = 14.2 [mA], and the light emitting element fixed, the light emitting elements are sequentially replaced, and light is applied to a certain reference plate. The photocurrent IL of the light receiving element when irradiated is measured to determine the magnitude of the light receiving sensitivity.

Table 2 shows the measurement results. Thus, it can be seen that the output variation is slightly less than twice on the light emitting element side and slightly less than four times on the light receiving element side.

  For this reason, when the density sensor 311 is replaced for some reason, if the stain determination of the density sensor 311 is performed as it is, the information of the density sensor 311 before replacement stored in the apparatus main body is used as it is. There is a fear that the accuracy of the dirt determination of the density sensor 311 may be reduced due to variations in the output of the sensor 311. Therefore, by providing the memory 313 with identifiable information such as the ID information of the density sensor 311, the ID information of the density sensor 311 stored in the apparatus main body and the actual information stored in the memory 313 are attached to the apparatus main body. It is possible to determine whether or not the density sensor 311 has been replaced by collating it with the ID information of the density sensor 311. If it is determined that the density sensor 311 has been replaced, the accuracy of stain determination of the density sensor 311 can be increased by performing control based on the information of the replaced density sensor 311.

Next, potential control called self-check, which is image density control, will be described. This self-check processing routine is performed at regular time intervals and at regular intervals when the density sensor is replaced and the power is turned on.
FIG. 1 is a plan view showing a positional relationship between a gradation pattern transferred onto the intermediate transfer belt 10 and a density sensor 311 mounted facing the gradation pattern, and FIG. 14 is a toner adhesion amount with respect to a developing potential during potential control. It is a graph which shows the linear approximation of. Table 3 is a potential control table.

Here, the procedure when the power is turned on is shown.
First, when the power is turned on, the ID information stored in the Address 1 of the concentration memory 313 is compared with the ID information of the concentration sensor 311 stored in the memory (RAM) 504 in the main device.
Here, if the ID information in the main body and the ID information in the memory 313 do not match, it is determined that the sensor has been replaced, a sensor replacement flag is set, and potential control is executed.
If the ID information matches, the lifetime is determined by looking at the LED lighting time stored in the memory 313. If the LED lighting time exceeds the lifetime, it is determined as the sensor lifetime. , Send sensor replacement notification to the call center via the network.
In addition, this LED lighting time does not use the exact life time as a threshold value, but considers the time lag from when the information is notified to the call center until the time when the service person actually replaces the sensor. It is desirable to set a time that is several hours shorter than the lifetime.
In consideration of the abnormal termination of the process for some reason during the potential control, the ID information stored in the internal memory is not rewritten (updated) at this point.

  If the in-body ID information matches the sensor ID information, the fixing temperature of the fixing device 25 is detected as a potential control execution condition when the power is turned on. Based on an input signal from a fixing temperature sensor (not shown), it is determined whether or not the fixing temperature of the fixing device 25 exceeds 100 ° C., and the potential control is executed when the fixing temperature of the fixing device 25 is 100 ° C. or lower. . When the temperature exceeds 100 ° C., the potential control is not executed.

In the potential control, first, the offset voltage (Voffset_reg, Voffset_dif) of the two density sensors 311 is measured before starting the plotter, and the plotter is started up after the measurement is completed. In this plotter start-up operation, as shown in FIG. 13, activation of motor loads such as each photosensitive drum motor, intermediate transfer belt motor, secondary transfer motor, etc., and charging, development, and transfer bias are performed in accordance with a predetermined image forming timing. Control load startup operation processing necessary for image forming operation such as startup operation is performed.
Further, as shown in FIG. 13, in this start-up operation process, the P sensor LED is turned on in synchronization with the start timing of the intermediate transfer motor, and at this time, a timer value for measuring the lighting time of the P sensor LED. To get.

  Next, about 3 seconds after the LED light output is stabilized, the regular reflection light (Vsg_reg) from the background portion (surface) of the intermediate transfer belt 10 is within a predetermined range (4.0 ± 0.2 V). Thus, the LED light emission amount is adjusted (referred to as Vsg adjustment). After the light amount adjustment, the belt background output (Vsg_reg, Vsg_dif) is stored in the main body RAM.

In addition, after the light amount adjustment, the LED current value (current value) stored in the memory 313 is compared with the LED current value (minimum value). Notification of sensor contamination to the call center via As soon as the notification is given, the service person is contacted and the cleaning work is performed by the service person.

It should be noted that the stain determination can be determined not only to satisfy Equation 1, but also to determine that the density sensor 311 is dirty when Equation 2 is satisfied.

For example, in Equation 2, when the LED current value (minimum value) is 10 [mA], the LED current value (current value) is 11 [mA], and the contamination determination threshold is 20 [%], the relationship shown in Equation 3 is obtained. Therefore, it is not determined that the density sensor 311 is dirty.

Further, in Equation 2, when the LED current value (minimum value) is 10 [mA], the LED current value (current value) is 13 [mA], and the contamination determination threshold is 20 [%], the relationship shown in Equation 4 is obtained. Therefore, Equation 2 is satisfied, and it is determined that the density sensor 311 is dirty.

  Note that the image forming apparatus according to the present exemplary embodiment does not have a cleaning mechanism that can be operated by the user, and thus the notification is made via the network. If the user can clean the density sensor 311 himself / herself, a screen (printer) on an external device terminal such as a PC or the like displayed on the operation unit of the image forming apparatus or connected thereto is displayed. Display on the driver or driver utility screen) to encourage cleaning.

After the sensor contamination determination, the LED current value (upper limit value) stored in the memory 313 is compared with the LED current value (current value), and if Equation 2 is satisfied, the LED current in the memory 313 is determined. Increase the value upper limit abnormal counter by one.

If Equation 5 does not hold, the LED current value upper limit abnormality counter is reset (zero is written).
If the count value after the count-up exceeds three times, that is, if a continuous LED current value upper limit abnormality occurs three times, it is determined that the sensor has reached the end of life, and a sensor replacement notification is sent to the call center via the network.

  Further, as the sensor contamination determination, the LED current value (current value) stored in the memory 313 is compared with the LED current value (initial value) at the initial stage of the sensor, and the LED current value (current value) is the initial value. It is also possible to determine that the density sensor 311 is dirty when the LED current value (initial value) becomes higher by a predetermined value.

  After this Vsg adjustment is completed, an electrostatic latent image having a gradation pattern is formed on each photosensitive drum 20. The formation positions of the gradation patterns of the respective colors are positions corresponding to the longitudinal positions of the two density sensors 311 shown in FIG. 1 (for C, M, and Y, 40 mm in front of the image center, K Is formed at a position of 40 [mm] on the back side with respect to the center of the image. In the present embodiment, 10 gradation patterns (each patch size is 15 × 20 [mm]) are formed at a predetermined interval of 10 [mm].

  In the next step, the output value of the potential sensor 320 for these gradation pattern portion potentials on the photosensitive drum 20 is read and stored in the RAM 504. Further, the development potential is calculated from this potential output and the development bias at the time of pattern image formation. The electrostatic latent images formed on the photosensitive drum 20 are developed by developing devices 61Y, 61C, 61M, and 61K, respectively, and are visualized to form toner images of respective colors.

  Next, the CPU 501 performs toner adhesion amount detection by the PP sensor 310 with respect to the gradation pattern formed on the intermediate transfer belt 10. In this toner adhesion amount detection, all of the regular reflection light output (Vsp_reg) and diffuse reflection light output (Vsp_dif) (10 patches × 4 colors) of the P sensor 310 with respect to the patch pattern which is a toner image of each color are stored in the RAM 504. .

Next, the toner adhesion amount is calculated.
This adhesion amount calculation algorithm is different because the black toner detection sensor and the color toner detection sensor have different sensor configurations.

First, the black toner patch adhesion amount conversion process will be described.
For the black toner adhesion amount calculation, an output ratio (Vsp / Vsg) between the belt background output (Vsg) and the pattern output (Vsp) is calculated, and this is applied to an adhesion amount conversion table (not shown) stored in the ROM. The amount of adhesion is calculated by referring to it.

Next, color toner patch adhesion amount conversion processing will be described. In addition, the meaning of the symbol (abbreviation) in the following description is as follows.
Vsg: transfer belt background portion output voltage Vsp: each pattern portion output voltage Voffset: offset voltage (output voltage at LED_OFF)
_Reg. ... Specular reflection light output (Regular Reflection)
_Dif. ... Diffuse reflected light output (Diffuse Reflection)
(Cf. JISZ8105: Refer to terms related to color)
[N] ... Number of elements: n array variables

拡散反射光出力増分：

[STEP 1] Data sampling: Vsp, ΔVsg calculation First, the difference from the offset voltage is calculated for all points [n] for both the regular reflection light output and the diffuse light output.
<Processing formula>
Specular light output increment:

Diffuse light output increment:

[STEP2] Calculation of sensitivity correction coefficient α ΔVsp_reg. [N], ΔVsp_dif. [N], ΔVsp_reg. [N] / ΔVsp_dif. [N] is calculated, and the coefficient α to be multiplied by the diffused light output (ΔVsp_dif [n]) is calculated when the component decomposition of the regular reflection light output is performed in STEP3.
<Processing formula>

正反射光出力の正反射成分：

[STEP 3] Component decomposition of regular reflection light The component decomposition of regular reflection light output is performed by the following equation.
<Processing formula>
Diffuse light component of specular reflection output:

Regular reflection component of specular reflection light output:

[STEP 4] Normalization of Regular Reflection Light Output_Specular Reflection Component Next, the ratio of each pattern portion output to the belt background portion output is taken and converted to a normalized value from 0 to 1.
<Processing formula>
Normalized value:

[STEP 5] Correction of Diffuse Light Output Background Change Next, a process of removing [diffuse light output component from belt background] from [diffused light output voltage] is performed.
<Processing formula>
Diffusion light output after correction:

ｘ［ｉ］：正反射光＿正反射成分の正規化値
Ｘ：正反射光＿正反射成分の正規化値の平均値
ｙ［ｉ］：地肌部変動補正後拡散光出力
Ｙ：地肌部変動補正後拡散光出力の平均値
なお、計算に用いるｘの範囲は、０．０６≦ｘ≦１である。 [STEP 6] Sensitivity correction of diffused light output The diffused light output after correction of background fluctuation is plotted against "normalized value of regular reflection light (regular reflection component)". The output sensitivity is obtained, and correction is performed so that this sensitivity becomes a predetermined target sensitivity.
Here, the sensitivity of the diffused light output is the slope of the straight line calculated by Equation 13, and a certain value of diffused light output after correcting the background portion fluctuation (a value of 0.3 here). 1.2), a correction coefficient for multiplying the current inclination is calculated and corrected.
The slope of the straight line is obtained by the method of least squares.

x [i]: Normalized value of regular reflection light_regular reflection component X: Average value of normalized value of regular reflection light_regular reflection component y [i]: Diffusion light output after correction of background portion fluctuation Y: Background portion fluctuation Average value of diffused light output after correction The range of x used in the calculation is 0.06 ≦ x ≦ 1.

  In this embodiment, the lower limit value of the range of x used for the calculation is 0.06, but this lower limit value is a value that can be arbitrarily determined within a range where x and y are in a linear relationship. The upper limit value is set to 1 because the normalized value is a value from 0 to 1.

A sensitivity correction coefficient γ is obtained so that a certain normalized value a calculated from the sensitivity thus obtained becomes a certain value b.

The sensitivity correction coefficient γ (current value) calculated here is compared with the sensitivity correction coefficient γ upper limit in the memory 313, and if Equation 15 holds, the sensitivity correction coefficient γ abnormality counter in the memory 313 is satisfied. Is counted up by one.

If the number 15 does not hold, the sensitivity correction coefficient γ upper limit abnormality counter is reset. (Write zero)
If the count value after the count-up exceeds 3, that is, if a three-time continuous sensitivity correction coefficient γ upper limit abnormality has occurred, it is determined that the sensor has reached the end of life, and a sensor replacement notification is sent to the call center via the network.

The diffused light output after the background portion fluctuation correction obtained in STEP 5 is corrected by multiplying by this sensitivity correction coefficient γ.
Diffuse light output after sensitivity correction: ΔVsp_dif ″

[STEP 7] Adhesion amount conversion Since all the correction processes for the temporal variation of the diffuse reflection output caused by the LED light amount reduction and the like have been performed by the above calculation processing, the adhesion amount is finally referred to by referring to the adhesion amount conversion table. Convert to.

  When the processing so far is completed normally, the LED current value (current value) and the sensitivity correction coefficient γ (current value) are written and updated in the memory 313 regardless of the sensor replacement flag.

Next, the LED current adjustment value (minimum value) stored in the memory 313 of the sensor board is compared with the adjusted LED current value (current value). Only when it is satisfied, the LED current adjustment value (minimum value) is stored in the memory 313.

  The minimum value of the LED current adjustment value is stored in this way when the LED adjustment is performed so that the received light output is within a predetermined range. Therefore, it is possible to perform the stain determination without the influence of the deterioration with the lapse of time by updating the minimum value.

As with the LED current value, the sensitivity correction coefficient γ is also compared and determined between the minimum value and the current value, and the sensitivity correction coefficient (minimum value) in the memory 313 is updated only when Equation 15 is satisfied.

  Thus, the reason why the sensitivity correction coefficient γ can be treated in the same manner as the LED current value is that, as with the LED current value, the calculated value increases when sensor contamination occurs.

If the sensor replacement flag is checked and it is determined that the sensor has been replaced, the following information is rewritten (updated).
First, the sensor ID information stored in the memory 313 is acquired, and the sensor ID information in the main body memory 504 is updated. Next, the LED current value (current value) in the memory 313 is stored in the LED current value (initial value), and the sensitivity correction coefficient (current value) is stored in the sensitivity correction coefficient γ (initial value).

As described above, the amount of adhesion for both the black toner and the color toner has been calculated. Next, the development γ is calculated.
FIG. 14 shows the adhesion amount data (toner per unit area) with respect to the development potential (difference between the development bias potential VB and the surface potential of the photosensitive drum 20, unit: [−Kv]) at the time of toner patch image formation. The amount of adhesion [mg / cm ² ]) is plotted.

  In order to determine the image forming conditions, the linear approximation formula shown in FIG. 14 (the slope is called development γ and the x intercept is called development start voltage) is calculated, and the potential necessary to obtain the target adhesion amount is calculated. Then, Vd, Vb, and Vl that match this potential are obtained by referring to a potential table as shown in Table 3.

  Next, the residual potential of the photoconductor drum 20 is detected, and the target potentials Vb, Vd, and Vl are corrected by the residual potential to obtain the target potential.

  Thereafter, the charging DC bias adjustment and the LD power adjustment are performed so as to obtain this target potential, the image forming conditions are stored in the image forming apparatus internal memory RAM 504, and the processing is ended.

  After the above series of operations is completed, the plotter is lowered to finish the process. In the plotter lowering operation, as shown in FIG. 13, the motor load of each photosensitive drum motor, intermediate transfer belt motor, secondary transfer motor, etc. is started, and charging, development, and transfer bias are performed according to the determined image forming timing. The control load lowering operation process necessary for the image forming operation such as the starting operation is performed.

The P sensor LED is also turned off in the fall operation process.
When the LED is OFF, the LED lighting time is calculated from the difference between the LED ON timer value and the LED OFF timer value, and stored in the memory 313.

Next, sensor check processing when the density sensor 311 is cleaned will be described.
In this embodiment, since the P sensor 310 is not provided with a cleaning mechanism, the determination as to whether or not the concentration sensor 311 has been cleaned is triggered by the operation of closing the front door.

  When the front door is closed, the above-described Vsg adjustment operation is performed, and the LED current value (current value) is updated.

If the result of comparison between the LED current value (current value) and the LED current value (minimum value) is that Expression 19 is satisfied, it is determined that the concentration sensor 311 has been cleaned, and the LED current value (minimum value) is determined. Write the LED current value (current value).

  Even in the case of this sensor check operation, the LED lighting time from LEDON is calculated at the LEDOFF timing and stored in the memory 313.

  In this embodiment, the energization time stored in the memory 313 is the energization time stored in the memory in the main body storage device, and the addition value is written in the memory 313 every 1 hr. This is not necessarily the case, and other methods may be used.

  If the machine to which the P sensor 310 according to the embodiment described above is attached has expired and has been collected for recycling, the memory 313 can be read to determine the operation history of the sensor. Or it will be possible to judge whether to use for resource recycling.

  In addition, when it is determined that reuse is possible and the reuse is performed, the reuse count can be used as a reuse determination condition by incrementing the counter value of the reuse count by one in the assembly process.

  In this embodiment, the application example to the density sensor 311 which is one form of the reflection type photosensor has been described. However, the photosensor is a combination of a light-emitting element and a light-receiving element, which is also in a dirty environment. Similar to the present embodiment even when applied to a sensor used in the market or a sensor that is exchanged and recycled, for example, a paper type detection sensor that is a form of a transmissive sensor, and a feedback sensor that is a form of a reflective optical sensor. The effect of can be obtained.

  In this embodiment, the ID information of the density sensor 311 is stored in the memory 313. However, the ID information for specifying the density sensor 311 is not ID information such as a serial number, but is stored in the memory 313, for example. An initial sensor value having a unique value may be stored. Further, it is not a requirement that the ID information of the density sensor 311 be stored in the memory 313. If the ID information can be acquired from the image forming apparatus to which the density sensor 311 is attached, the ID sensor 311 has another form. It doesn't matter.

  In the present invention, a latent image is formed on a photoconductor for each color shown in FIG. 15 and developed, and a multicolor image is formed by sequentially superposing colors on a transfer material to form a so-called rotary development image. It can also be applied to a forming apparatus.

As described above, according to the present embodiment, the irradiation light emitted from the LED of the light emitting element which is the light emitting means provided in the copying machine main body is received by the light receiving element which is the light receiving means via the irradiation object, thereby irradiating. A P sensor 310 that is an optical sensor unit having a density sensor 311 that is an optical detection unit that detects optical characteristics of an object has a memory 313 that is information storage means for storing information. Thereby, the life determination information of the density sensor 311 included in the characteristic value information of the density sensor 311 can be stored as information to be stored in the memory 313. Therefore, when the P sensor 310 is recycled, the life of the density sensor 311 is determined based on the life determination information of the density sensor 311 stored in the memory 313, and the reusability determination of the P sensor 310 is performed based on the determination result. be able to. Therefore, even if the P sensor 310 is detached from the apparatus main body, the life determination information of the density sensor 311 can be referred to from the memory 313 included in the P sensor 310, so that it is possible to accurately determine whether or not the P sensor 310 can be reused.
In addition, according to the present embodiment, as the lifetime determination information, the LED current upper limit value, the sensitivity correction coefficient γ upper limit value, the LED current upper limit abnormal count number, and the sensitivity correction coefficient γ upper limit, which are lifetime limit information of the concentration sensor 311 in particular. The abnormal count number is stored in the sensor 313. Thereby, the LED current value (upper limit value) of the initial characteristic value of the concentration sensor 311 is compared with the LED (current value), and the LED current value (current value) is higher than the LED current value (upper limit value). Increases the LED current value upper limit abnormality counter in the memory 313 by one. If the LED current value (current value) is lower than the LED current value (upper limit value), the LED current value upper limit abnormality counter is reset (zero is written). Therefore, for example, when the count value after counting up exceeds three times, that is, when the upper limit abnormality of the LED current value occurs three times, it can be determined that the life of the concentration sensor 311 is reached.
Similarly, the sensitivity correction coefficient γ (current value) is compared with the sensitivity correction coefficient γ (upper limit value). When the sensitivity correction coefficient γ (current value) is larger than the sensitivity correction coefficient (upper limit value), the sensitivity correction coefficient γ upper limit abnormality counter in the memory 313 is incremented by one. If the sensitivity correction coefficient γ (current value) is smaller than the sensitivity correction coefficient (upper limit value), the sensitivity correction coefficient γ upper limit abnormality counter is reset (zero is written). Thereby, for example, when the count value after the count-up exceeds three times, that is, when the three-time continuous sensitivity correction coefficient γ upper limit abnormality occurs, it can be determined that the life of the density sensor 311 has been reached.
Further, according to the present embodiment, the LED lighting time of the density sensor 311 that is the operation history information of the density sensor 311 is stored in the sensor 313 as the lifetime determination information, and the LED lighting time is referred to from the memory 313. If the LED lighting time exceeds the lifetime, it can be determined that the concentration sensor 311 has a lifetime.
Further, according to the present embodiment, among the initial characteristic value information, at least the LED current value (initial value) that is the initial value of the light emission output of the LED cannot be obtained when the concentration sensor 311 is normally used. Value. The apparatus main body reads that the LED current value (initial value) of the concentration sensor 311 is a predetermined value, and determines that the P sensor 310 incorporated in the apparatus main body has been replaced. The predetermined value is set to 0, which is a value that can never be obtained when the density sensor 311 is normally used, for example. Thereby, when the apparatus main body reads 0 which is the predetermined value, information that the concentration sensor 311 incorporated in the apparatus main body has been replaced can be obtained.
Further, according to the present embodiment, the characteristic value information includes post-cleaning characteristic value information at the start of use of the density sensor 311 after cleaning. Since the luminous intensity of the LED decreases due to deterioration over time, the LED current value (current value) is adjusted to a high value in order to make the luminous intensity received by the light receiving element constant. Therefore, the apparatus main body may determine that the density sensor 311 is dirty even though the density sensor 311 is not dirty. Therefore, the reference for determining the contamination of the density sensor 311 is not the LED current value (initial value) at the initial time of the density sensor 311 but the LED current value (minimum value) immediately after cleaning the density sensor 311. Thereby, when the LED current value (current value) is higher than the LED current value (initial value) immediately after the cleaning by a predetermined value, it is determined that the concentration sensor 311 is dirty, thereby deteriorating the LED over time. Therefore, it is possible to prevent erroneous determination of the contamination determination of the density sensor 311.
Further, according to the present embodiment, the characteristic value information includes ID information that is individual identification information of the P sensor 310. As a result, the ID information stored in the memory 313 of the P sensor 310 is compared with the ID information of the P sensor 310 stored in the internal memory of the apparatus. If the ID information does not match, the apparatus main body Information that the concentration sensor 311 in the apparatus main body has been replaced can be obtained. The ID information of the P sensor 310 need not be stored in the memory 313 as long as the ID information of the P sensor 310 can be acquired from the apparatus main body side in which the P sensor 310 is incorporated. For example, an identification member having ID information of the P sensor 310 may be provided in the P sensor 310.
Further, according to the present embodiment, the characteristic value information includes reuse number information of the P sensor 310. Thus, when the density sensor 311 is determined to be reusable and reused, if the counter value of the number of reuses is incremented by 1, the number of reuses can be used as a reuse determination condition at the next reuse determination.
Further, according to the present embodiment, the characteristic value information includes the initial characteristic value information when the density sensor 311 is initial. Thereby, the LED current value (initial value) which is the light emission output (initial value) at the initial time of the density sensor 311 can be used for the stain determination of the density sensor 311. That is, when the density sensor 311 is contaminated, the light entering the light receiving element is reduced by the dirt, so that the LED current value (current value) that is the light emission output (current value) is adjusted to a high value to compensate for this. Is done. Therefore, when the LED current value (current value) is higher than the initial LED current value (initial value) by a predetermined value, it can be determined that the concentration sensor 311 is dirty.
In addition, according to the present embodiment, the P sensor 310 is a toner image that is a form of a reflective optical sensor that receives reflected light when a light irradiated from a light emitting element is reflected by an irradiation object. The above-described effects can be obtained with respect to the density sensor 311 for detecting the toner density, but the reflection type optical sensor is not limited to the density sensor 311. In addition, even when applied to a transmission type optical sensor that receives transmitted light when light irradiated from a light emitting element passes through an object to be irradiated by a light receiving element, the same effect as this embodiment can be obtained and transmitted. As one form of the mold optical sensor, there is a paper type detection sensor for detecting the type of paper as a recording medium.

The schematic block diagram of P sensor provided with the memory which is the characterizing part of this embodiment. The schematic block diagram of P sensor provided with two sensors for position shift detection, and one density sensor. The schematic block diagram of P sensor which arranged four density sensors in parallel. 1 is a schematic configuration diagram of an entire copying machine that is an image forming apparatus according to an embodiment. FIG. FIG. 2 is an enlarged view showing a configuration of a copying machine main body. The schematic block diagram of the reflection type sensor which detects only regular reflection light. The schematic block diagram of the reflection type sensor which detects only diffuse reflection light. The schematic block diagram of the reflection type sensor which detects both regular reflection light and diffuse reflection light. The schematic block diagram of the reflection type sensor which provided the beam splitter in the light emission path / light reception path. FIG. 3 is an enlarged view showing a configuration of two adjacent image forming units. FIG. 2 is a block diagram showing electrical connection of each unit provided in the copying machine. The graph which shows the luminous intensity residual rate with respect to LED operation time. Explanatory drawing of a starting operation process. 6 is a graph showing a linear approximation of the toner adhesion amount with respect to the development potential during potential control. 1 is a schematic configuration diagram of a rotary development type image forming apparatus.

Explanation of symbols

310 P sensor 311 Concentration sensor 312 Misalignment detection sensor 313 Memory

Claims (10)

Image forming means for forming an image on a recording medium;
An optical detection unit that detects optical characteristics of the irradiation target by receiving the irradiation light emitted from the light emitting unit through the irradiation target with a light receiving unit, and a housing that houses the optical detection unit In the image forming apparatus provided with an optical sensor unit exchangeable with the apparatus main body,
Information storage means for storing information is provided in the housing,
Processing means for performing at least one of information writing processing and reading processing on the information storage means;
The information includes life determination information used for life determination of the optical detection unit, and the life determination information is a time shorter by a predetermined time than a life time of the optical detection unit,
The information includes replacement determination information, which is information that allows the apparatus main body to determine that the optical sensor unit in the apparatus main body has been replaced. As the replacement determination information, the light emission of the light emitting means at an initial time is included. An image forming apparatus, wherein an output value is used and a light emission output value is set to a unique value that cannot be obtained in a state where the optical detection unit is normally used. The image forming apparatus according to claim 1.
The upper SL information, the image forming apparatus characterized by including the characteristic value information showing characteristic values of the optical detection unit. The image forming apparatus according to claim 2.
The upper SL characteristic value information, the image forming apparatus characterized by including the initial state characteristic value information of the optical detector initial time. The image forming apparatus according to claim 2 or 3,
The upper SL characteristic value information, the image forming apparatus, characterized in that it includes cleaning after characteristic value information is a characteristic value of the optical detection unit after being cleaned. The image forming apparatus according to claim 2, 3 or 4 ,
The upper SL characteristic value information, the image forming apparatus characterized by including the individual identification information of the optical sensor unit. The image forming apparatus according to claim 2, 3, 4 or 5.
The upper SL characteristic value information, the image forming apparatus characterized by including the reuse frequency information of the optical sensor unit. The image forming apparatus according to claim 1, 2, 3, 4, 5 or 6.
Upper Symbol optical detection unit, an image forming apparatus, characterized in that the reflected light when illumination light emitted from the light emitting means is reflected by the object to be irradiated are those received by the light receiving means. The image forming apparatus according to claim 1, 2, 3, 4, 5 or 6 .
Upper Symbol optical detection unit, an image forming apparatus, characterized in that the transmitted light when the irradiation light irradiated from the light emitting means has passed through the object to be irradiated are those received by the light receiving means. The image forming apparatus according to claim 7.
The image forming apparatus, wherein the optical detection unit detects an image density. The image forming apparatus according to claim 8.
The image forming apparatus according to claim 1, wherein the optical detection unit detects the type of the recording medium.

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