JP2007072212A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of surely preventing the occurrence of image deletion without causing the lowering of durability of a photoreceptor drum or the soiling of the apparatus while restraining power consumption. <P>SOLUTION: In the image forming apparatus where a drum heater 300 and a shielding member 102 are concurrently used, in a standby mode, the drum heater 300 is used to prevent the image deletion from occurring, and also the shielding member 102 is moved to a retracting position, and light or a current of air is applied to the catalyst substance part of the shielding member 102 so as to decompose ozone product. On the other hand, in an energy saving mode, the shielding member 102 is used instead of the drum heater 300 so as to prevent the image deletion from occurring. Thus, the drum heater 300 need not be always turned on in order to prevent the image deletion, so that an energy saving effect is obtained, and the occurrence of the image deletion is surely prevented without causing the lowering of the durability of the photoreceptor drum and the soiling of the apparatus. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and an image forming method thereof.

  A corona charger, which is the mainstream of the charging method, applies a high voltage of about 5 to 10 kV to a metal wire having a diameter of about 50 to 100 μm, ionizes the atmosphere by corona discharge, and imparts charge to a counter object such as a photoreceptor. . In the process, the wire itself also absorbs dirt, and periodic cleaning and replacement are necessary. A large amount of ozone is generated with corona discharge. On the other hand, electrophotographic photoreceptors used in recent years have the disadvantage that the surface of the photoreceptor becomes increasingly sensitive to humidity and easily adsorbs moisture due to the influence of corona products derived from ozone generated from the charger. is doing.

  In a conventional image forming apparatus, generally, the surface of a photosensitive drum is charged by a corona charger to form an electrostatic latent image, and an image is formed on a transfer material. The ozone product (nitrate ions) is generated by the reaction between the ozone and moisture in the air, and this ozone product adheres to the photosensitive drum surface that is sensitive to humidity. This ozone product has a problem in that the resistance of the surface of the photosensitive drum is lowered and an electrostatic latent image is lost, so-called image flow occurs.

In order to prevent such an image flow, the surface of the photosensitive drum is constantly heated by a heater to remove moisture on the surface of the photosensitive drum (see Patent Document 1), or formed from a magnet roller and magnetic toner. A method of removing the corona product by rubbing the surface of the photoreceptor with a brush (see Patent Document 2) has been proposed. In addition, a technique has been proposed in which a shielding plate is placed between the corona charger and the photoconductor (Patent Document 3). Furthermore, a method has been proposed in which a photocatalytic substance capable of decomposing a discharge product is applied to a casing of a charger, and the photocatalytic substance is excited by light emitted during discharge to remove the discharge product (Patent Document). 4).
No. 1-334205 Japanese Patent Publication No. 2-38956 JP-A 61-260265 JP 2000-356932 A

  However, in the technique of Patent Document 1, since the surface of the photosensitive drum is constantly heated, there is a problem that not only the number of printed sheets is reduced, but the constant heating by the heater causes an increase in power consumption. Even in the technique of Patent Document 2, the number of printed sheets is reduced because the surface of the photoreceptor is rubbed with a brush.

  Further, although the technique of Patent Document 3 has an effect that the ozone product does not adhere to the surface of the photosensitive drum, the ozone product continues to be deposited on the shielding object, and finally the apparatus is generated by an air flow in the apparatus. It will scatter inside and cause contamination of the device. In addition, regular cleaning for removing dirt on the shielding member by a service person is required.

  Further, in the technique of Patent Document 4, since there is no photocatalytic substance between the charger and the photosensitive drum, an ozone product generated by a reaction between residual ozone that could not be decomposed and moisture in the air. However, since it adheres on the surface of the photosensitive drum, the above-mentioned problem of image flow is not sufficiently solved.

  SUMMARY OF THE INVENTION In view of the above-described conventional problems, the present invention can reliably prevent the occurrence of an image flow while suppressing power consumption and without causing a decrease in durability of the photosensitive drum or contamination of the apparatus. An object of the present invention is to provide a forming apparatus and an image forming method thereof.

  In order to achieve the above object, the present invention provides a photosensitive member on which a latent image based on an image signal is formed, charging means for charging the surface of the photosensitive member by discharge, and forming the latent image on the photosensitive member. Therefore, the image forming apparatus includes an exposure unit that exposes the surface of the photosensitive member charged by the charging unit, and has at least two standby modes of a standby mode and an energy saving mode that consumes less power than the standby mode. In the apparatus, a heat generating means for warming the photoconductor, a shielding member for shielding between the photoconductor and the charging means, a shielding position for shielding between the charging means and the photoconductor, and the charging A moving means for moving the shielding member to a retracted position that opens between the means and the photoconductor, and in the energy saving mode, the heating means is turned off and the front is turned off. As shield means is moved to the blocking position, characterized in that a control means for controlling said heating means and said moving means.

  Further, the present invention provides a photosensitive member on which a latent image based on an image signal is formed on a surface, charging means for charging the surface of the photosensitive member by discharge, and forming the latent image on the photosensitive member. An image forming apparatus comprising: an exposure unit that exposes the surface of the photoreceptor charged by the charging unit; and having at least two standby modes of a standby mode and an energy saving mode that consumes less power than the standby mode. A heating unit for heating the photosensitive member; a shielding member for shielding between the photosensitive member and the charging unit; a shielding position for shielding between the charging unit and the photosensitive member; A moving means for moving the shielding member is provided in advance in a retracted position that opens between the charging means and the photoconductor, and the heat generating means is turned off in the energy saving mode. As Rutotomoni said shield means is moved to said blocking position, and controlling the heating means and the moving means.

  According to the present invention, it is possible to reliably prevent the occurrence of an image stream while suppressing power consumption. In addition, it is possible to reliably prevent the occurrence of image flow without lowering the durability of the photosensitive member or causing the image forming apparatus to become dirty, and to reduce the discharge amount of the discharge product.

  An image forming apparatus and an image forming method according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
<Overall configuration of image forming apparatus>
FIG. 1 is a cross-sectional view of the main part showing the overall configuration of the image forming apparatus according to the first embodiment of the present invention.

  This image forming apparatus is constituted by a full-color printer, for example, and has a photosensitive drum 1 as an image carrier. The photosensitive drum 1 is provided so as to be rotated in the direction of arrow A by a motor (not shown), and a drum heater (described later) for heating the photosensitive drum 1 is provided therein. In addition to the primary charger 7, the exposure device 8, the developing unit 13, the transfer device 10, and the cleaner device 12, a shielding device 100 that characterizes the present embodiment is disposed around the photosensitive drum 1.

  The photosensitive drum 1 uses amorphous silicon as a material. The developing unit 13 includes three color developing devices 13Y, 13M, 13C and a black developing device 14 for full color development. The developing devices 13Y, 13M, 13C, and 14 develop the latent images on the photosensitive drum 1 with toners of Y (yellow), M (magenta), C (cyan), and K (black), respectively. When developing each color of Y, M, and C, the developing unit 13 is rotated by a motor (not shown), and the developing device for the color is aligned so as to contact the photosensitive drum 1. The black developing device 14 is configured such that the developing roller is always in contact with the photosensitive drum, and the black developer is controlled by controlling the high voltage bias so that black toner is not developed during development of each color other than black. At the time of development, the black toner is developed by switching to a high voltage bias at which the toner develops.

  The toner images of the respective colors developed on the photosensitive drum 1 are sequentially transferred onto the belt 2 as an intermediate transfer member by the transfer device 10, and the four color toner images are superimposed. The belt 2 is stretched around rollers 17, 18, 19 and 20. Among these, the roller 17 is connected to a driving source (not shown) and functions as a driving roller for driving the belt 2, the rollers 18 and 20 function as tension rollers for adjusting the tension of the belt 2, and the roller 19 is a secondary roller. It functions as a backup roller for the transfer roller 21 as a transfer device. A belt cleaner 22 is provided at a position facing the roller 17 with the belt 2 interposed therebetween, and residual toner on the belt 2 is scraped off by a blade.

  The recording paper drawn from the recording paper cassette 23 to the conveyance path by the pickup roller 24 is fed to a nip portion, that is, a contact portion between the transfer roller 21 and the belt 2 by a pair of rollers 25 and 26. The toner image formed on the belt 2 is transferred onto the recording paper at the nip portion, thermally fixed by the fixing device 5 and discharged outside the device.

  In the color printer configured as described above, an image is formed as follows.

  First, a voltage is applied to the charger 7 to uniformly negatively charge the surface of the photosensitive drum 1 with a predetermined charged portion potential. Subsequently, exposure is performed by an exposure device 8 including a laser scanner so that the charged image portion on the photosensitive drum 1 has a predetermined exposure portion potential, and a latent image is formed. The exposure device 8 is turned on / off based on the image signal to form a latent image corresponding to the image.

  A developing bias set in advance for each color is applied to the developing roller of the developing device 13Y and the like, and the latent image is developed with toner when passing through the position of the developing roller and visualized as a toner image. The toner image is transferred to the belt 2 by the transfer device 10 and further transferred to the recording paper by the transfer roller 21 and then fed to the fixing device 5. In full-color printing, toners of four colors are superimposed on the belt and then transferred onto the recording paper. The toner remaining on the photosensitive drum 1 is easily cleaned by a preliminary cleaning device, and is removed and collected by the cleaner device 12. Finally, the photosensitive drum 1 is uniformly removed by a static eliminator (not shown). The charge is discharged to around 0 volts to prepare for the next image forming cycle.

  The image forming timing of the color printer is controlled with reference to a predetermined position on the belt 2. The belt 2 is stretched around rollers including a driving roller 17, tension rollers 18 and 20, and a backup roller 19, and a predetermined tension is applied by the tension rollers 18 and 20.

  Between the backup roller 19 and the tension roller 20, a reflective sensor 36 for detecting the reference position is disposed. The reflective sensor 36 detects a marking such as a reflective tape provided at the end of the outer peripheral surface of the belt 2 and outputs an I-top signal.

  The peripheral length of the photosensitive drum 1 and the peripheral length of the belt 2 have an integer ratio represented by 1: n (n is an integer). With this setting, the photosensitive drum 1 rotates an integer during one revolution of the belt 2 and returns to the same state as before the belt one revolution, so that four colors are superimposed on the intermediate transfer belt 2. At this time (the belt rotates four times), it is possible to avoid color misregistration due to uneven rotation of the photosensitive drum 1.

  In the intermediate transfer type image forming apparatus as described above, after the I-top signal is detected, exposure is started by the exposure device 8 including a laser scanner after a predetermined time has elapsed. Further, as described above, since the photosensitive drum 1 rotates an integer while the belt 2 makes one revolution and returns to the same state as before the belt one revolution, a toner image is always formed on the belt 2 at the same position. Although the toner image size also changes depending on the paper size, there is a range on the belt 2 where the toner image is never placed.

  The potential sensor 3 is located between the primary charger 7 and the black developing device 14 and is located downstream of the exposure point on the photosensitive drum 1 in the rotation method, and is used for measuring the charging potential on the photosensitive drum 1. Is.

<Configuration of Charging Device According to this Embodiment>
FIGS. 2A and 2B are schematic views showing a peripheral portion of the shielding device 100 according to the present embodiment, and FIG. 3 is an external perspective view showing a configuration example of the shielding device 100. FIG.

  The primary charger 7 includes a casing 104 having an opening that opens toward the photosensitive drum 1, a discharge wire 103 serving as a discharge electrode disposed near the center of the casing 104, and a predetermined wire attached to the discharge wire 103. And a high voltage power source 105 for applying a high voltage. In the primary charger 7, the high voltage power source 105 applies a voltage to the discharge wire 103, thereby generating a corona discharge in the discharge wire 103. The casing 104 is made of a metal such as aluminum or stainless steel, and shields a portion other than the opening toward the photosensitive drum 1.

  A shielding device 100 is installed in the vicinity of the primary charger 7. As shown in FIGS. 2A and 2B, the shielding device 100 moves a movable shielding member 102 disposed between the primary charger 7 and the photosensitive drum 1, and the shielding member 102. And a light emitting lamp 106. The light shielding lamp 106 includes a shielding member moving device 113 for shielding, a shielding member position detection sensor 114 for detecting a position of the shielding member 102 (shielding position / retracted position to be described later).

  As shown in FIG. 3, the shielding member 102 has a thin plate shape, a shielding position where the shielding member moving device 113 shields the opening of the casing 104 (see FIG. 2A), and the opening of the casing 104. It is configured to be movable between a retracted position (see FIG. 2B) that does not shield the part. That is, the shielding member moving device 113 includes, for example, a motor (not shown) whose driving is controlled by the control unit 40 (described later) and a gear (not shown) supported on the rotation shaft of the motor. Yes. Then, the gear of the shielding member moving device 113 is screwed into a rack 102a formed in a direction orthogonal to the longitudinal direction of the shielding member 102, and the shielding member 102 is moved to the shielding position / retracted position by the rotation of the motor. It is like that.

  Further, the shielding member 102 contains a photocatalytic substance for decomposing nitrogen oxides generated by the ozone generated by the discharge of the primary charger 7 and reacting with moisture in the air. In this embodiment, titanium oxide is used as the photocatalytic substance. Titanium oxide generates electrons (e−) in the conduction band and holes (h +) in the valence band when light (ultraviolet light) energy having a band gap (3.2 eV) or more is supplied. Each of the generated electrons and holes diffuses on the surface of titanium oxide and causes a photocatalytic reaction. By this reaction on the titanium oxide surface, photogenerated electrons and holes react with adsorbed oxygen and adsorbed water on the surface to generate active oxygen, and the ozone product adsorbed on the surface is oxidized and reduced to be decomposed.

  The light-emitting lamp 106 can irradiate near ultraviolet rays having a wavelength that can be absorbed by titanium oxide (380 nm) or less. When a visible light responsive photocatalyst is used as a photocatalyst, a visible light lamp having a wavelength of 400 to 600 nm may be used.

  In addition, when a photocatalytic substance is applied to the shielding member, a substance having an adsorbing action such as activated carbon or apatite may be provided at the same time. By using a photocatalytic substance and such an adsorbent in combination, the adsorption capacity of the ozone product is increased and the decomposition capacity of the ozone product is also improved.

  In this embodiment, the photocatalytic substance is given to the shielding member 102. However, instead of the photocatalytic substance, an adsorbent such as activated carbon or apatite may be used. Moreover, you may comprise only a sheet metal, a mold, and a cloth material.

<Drum heater configuration>
FIG. 4 is a schematic view showing a control system of a drum heater provided in the interior of the photosensitive drum 1.

  As shown in the figure, a drum heater (a planar heating element or a rod-like heating element) 300 is provided inside the photosensitive drum 1, and the photosensitive drum 1 can be heated and held as necessary. It is configured.

  For example, a drum heater 300 made of a planar heating element is mounted along the inner surface of the photosensitive drum 1 as shown in FIG. The drum heater 300 is heated by the power supplied from the drum heater power source 400, and its temperature is detected by the thermistor 500. And the control part 40 controls the electric power supplied to the drum heater 300 according to detected temperature (temperature control).

  In the photosensitive drum 1, the supply line from the power source 400 and the line from the control unit 40 to the thermistor 500 are directly connected so that the drum heater 300 can rotate. Actually, it can be connected via a slip ring or the like, but the description is omitted because it is a conventionally known technique.

  The heating temperature of the photosensitive drum 1 by the drum heater 300 is controlled at about 37 ± 2 ° C. This varies somewhat depending on the composition of the toner to be used and the contacted object (blade, fur brush, etc.) of the cleaner device 12, but if the toner is used at a too high temperature, the toner may block or the cleaner using the blade. In the device 12, since the blade is deformed or deteriorated, it is necessary to control it at a certain low temperature.

<Control system configuration>
FIG. 5 is a block diagram illustrating a schematic configuration of a control system of the image forming apparatus according to the first embodiment.

  The control unit 40 includes a CPU, a ROM, a RAM, and the like, and controls the entire operation of the image forming apparatus according to the present embodiment. This will be specifically described below.

  The control unit 40 is connected to the shielding member moving device 113 and the shielding member position detection sensor 114 described above in order to execute movement control (FIGS. 6 and 7) of the shielding member 102 described later. The thermistor 500 and the drum heater power source 400 are connected to execute the above-described temperature control of the photosensitive drum 1 and the like. Further, a light-emitting lamp 106 is connected to execute a light irradiation process described later.

  In addition, the control unit 40 performs laser light amount control of the exposure apparatus 8. Hereinafter, this laser light quantity control will be described.

  First, image data is input to the image input unit 41, and the data is sent to the image processing unit 42 as 8-bit image data. The image processing unit 42 performs image processing for optimizing the toner image with respect to the performance of the copying machine main body, and develops the image data for each color of Y, M, C, K as an output result, The data is stored in the memory in the image processing unit 42 and held.

  Next, a color output signal corresponding to the color to be output is transmitted from the control unit 40 to the image processing unit 42, and the color data to be output is transmitted to the PWM generator 43 as 8-bit data. The PWM generator 43 sets a pulse width for controlling the laser emission time in one pixel based on the transmitted 8-bit multi-value data, and transmits a pulse signal to the next laser driver 44.

  The laser driver 44 includes a light amount control unit 46 that adjusts the light amount and an on / off control unit 45 that switches on / off of the laser in the image area and the non-image area as internal circuits. The on / off control unit 45 receives the image area timing and the margin information for the image paper from the control unit 40, and turns on the laser with the data from the PWM control unit 43, which is image data, or forcibly. Controls whether to turn on or off.

  Next, laser light quantity adjustment will be described. Depending on the operation status of the image forming apparatus, the control unit 40 transmits information indicating whether it is a non-image area or an exposure timing of which color. The selector 49 reads out a set value provided for each non-image area or each color from the memory unit 50 storing a predetermined laser light amount adjustment value based on information from the control unit 40, and outputs the set value to the DA converter 48. To do. The laser light amount adjustment value converted into an analog signal by the DA converter 48 is input to the light amount control unit 46 in the laser driver 44. The light amount control unit 46 monitors the input laser light amount setting value and the output current of the photodiode provided in the laser element 47, and controls the current flowing to the laser so that the laser light amount becomes the laser light amount setting value. Adjust the amount of laser light.

<Moving control of shielding member>
Next, movement control of the shielding member 102 will be described with reference to FIGS. 6 and 7.

  FIG. 6 is a flowchart showing a movement control process when the shielding member 102 according to the first embodiment is powered on. A control program for realizing the shielding member movement control process is, for example, in the control unit 40. It is stored in the ROM and executed by the CPU in the control unit 40.

  First, in step S201, it is determined whether the image forming apparatus is turned on. When the power is input, the control unit 40 determines whether the shielding member 102 is in the shielding position (see FIGS. 2A and 3) based on the output of the shielding member position detection sensor 114 (step S202). If the shielding member 102 is not in the shielding position, the movement control process is terminated.

  When the shielding member 102 is in the shielding position, the process proceeds to step S203, where the control unit 40 drives the shielding member moving device 113 to move the shielding member 102 to the retracted position, and this movement control process is terminated.

  FIG. 7 is a flowchart showing the movement control process in the standby mode of the shielding member 102 according to the first embodiment, and this process is also executed by the CPU in the control unit 40 as in the process of FIG.

  First, in step S401, the control unit 40 determines whether or not the image forming apparatus is in a standby mode that is waiting for a print job. If it is not in the standby mode, it is determined that the print job is being executed, and this process is terminated.

  If it is in the standby mode, the process proceeds to step S402 to determine whether or not it is in the energy saving mode. It is possible to shift to the energy saving mode also by pressing an energy saving key from an operation unit (not shown) of the image forming apparatus, and automatically enters the energy saving mode after a predetermined time has elapsed after the end of the print job. You may migrate.

  If in the energy saving mode, the control unit 40 controls the drum heater power supply 400 to turn off the drum heater 300 (step S403), and then the control unit 40 controls the shielding member moving device 113 to control the shielding member 102. Is moved to the shielding position where the photosensitive drum 1 is shielded (step S404), and this process is terminated.

  On the other hand, if it is determined in step S402 that the mode is not the energy saving mode, the process proceeds to step S405, where the control unit 40 controls the drum heater power source 400 to turn on the drum heater 300, and ends this process.

  In this way, in the standby mode, which is a standby time for a print job, the image is prevented from moving by turning on the drum heater 300 without moving the shielding member 102 to the retracted position and using it. In the energy saving mode, which consumes less power than the standby mode, the drum heater 300 is turned off and the shielding member 102 is moved to the shielding position between the primary charger 7 and the photosensitive drum 1 to prevent image flow. To do. At this time, since the drum heater 300 is turned off, power consumption can be reduced.

<Light irradiation treatment>
The ozone product deposited on the shielding member 102 is not decomposed as it is. Therefore, the ozone product deposited on the shielding member 102 is decomposed by performing the light irradiation treatment described below.

  FIG. 8 is a flowchart showing the light irradiation process according to the present embodiment. A control program for realizing the light irradiation process is stored in, for example, a ROM in the control unit 40, and It is executed by the CPU.

  The light irradiation process is performed at the following light irradiation timing in order to decompose the ozone product deposited on the shielding member 102. That is, this process is performed when the predetermined number of prints is reached, and the time when ozone products are generated after the end of the print job is predicted, and after that time, the image forming apparatus is in the standby mode state. Implemented when

  First, the control unit 40 determines whether it is the light irradiation timing as described above in step S211. If the light irradiation timing is not reached, this process is terminated. If it is a light irradiation timing, it will progress to step S212 and it will be judged whether the shielding member 102 exists in a retracted position. If the shielding member 102 is not in the retracted position, this process ends.

  If the shielding member 102 is in the retracted position, the process proceeds to step S213, the light emitting lamp 106 is turned on, and light is emitted toward the shielding member 102. Next, it is determined whether or not irradiation has been performed for a predetermined time (step S214). If the light-emitting lamp 106 is turned on for a predetermined time, it is determined that the ozone product has been decomposed and the light-emitting lamp 106 is turned off (step S215). ), This process is terminated.

  In this manner, the ozone product deposited on the shielding member 102 can be decomposed by regularly irradiating the shielding member 102 with near-ultraviolet light. For this reason, the amount of ozone product scattered in the image forming apparatus is drastically reduced, and the maintenance work of the apparatus by the service person is also reduced.

<Advantages of this embodiment>
According to the image forming apparatus of the present embodiment, the drum heater 300 provided inside the photosensitive drum 1, the shielding member 102 for shielding between the photosensitive drum 1 and the primary charger 7, And a moving device 113 that moves the shielding member 102 to the shielding position / retreat position. Furthermore, there are at least two standby modes of a standby mode and an energy saving mode in which power consumption is smaller than that of the standby mode.

  In the standby mode, the shielding member 102 is moved to the retracted position, and the drum heater 300 is turned on to prevent the ozone product from adhering to the surface of the photosensitive drum 1 and to prevent the image flow. To prevent. On the other hand, in the energy saving mode, the drum heater 300 is turned off and the shielding member 102 is moved to the shielding position. Thus, in the energy saving mode, the shielding member 102 shields between the photosensitive drum 1 and the primary charger 7, so that the remaining ozone product is transferred from the primary charger 7 side onto the surface of the photosensitive drum 1. It can be prevented from moving and adhering, and image flow can be prevented. Furthermore, since the drum heater 300 is turned off during the energy saving mode, it is possible to reduce power consumption and to reduce the decrease in the number of printing sheets.

  Further, since the photocatalytic substance or the catalytic substance that reacts with the wind is given to the shielding member 102, the ozone product generated by the primary charger 7 can be decomposed. Therefore, it is possible to prevent contamination of the shielding member 102 due to ozone products and contamination of the apparatus due to ozone products scattered from the shielding member 102 in advance. Therefore, periodic cleaning for removing the dirt on the shielding member 102 by a service person becomes unnecessary, and further, the amount of ozone discharged from the apparatus can be reduced.

  As described above, in the present embodiment, the drum heater 300 and the shielding member 102 are used together, and in the standby mode, the drum heater 300 is used to prevent image flow and the shielding member 102 is moved to the retracted position. The ozone product is decomposed by moving and applying light or wind to the catalytic material portion of the shielding member 102. On the other hand, during the energy saving mode, the shielding member 102 is used instead of the drum heater 300 to prevent the image from flowing. As a result, there is no need to keep the drum heater 300 on at all times to prevent the image flow, so that there is an energy saving effect, and the occurrence of the image flow can be achieved without deteriorating the durability of the photosensitive drum and contamination of the apparatus. Can be reliably prevented.

[Second Embodiment]
<Configuration according to the second embodiment>
In the second embodiment, instead of the photocatalytic substance, a wind catalytic substance that exhibits catalytic action by wind pressure is included in the shielding member. In this case, instead of the light emitting lamp 106, a blower fan that generates wind is used.

  9A and 9B are schematic configuration diagrams showing the periphery of the primary charger 7 according to the second embodiment, and FIG. 10 shows the structure of the shielding member according to the second embodiment. It is sectional drawing shown.

  The configuration shown in FIGS. 9A and 9B is different from the configuration shown in FIGS. 2A and 2B only in the blower fan 111 and the shielding member 112. That is, the shielding device 200 according to the present embodiment includes the blower fan 111, the shielding member 112, the shielding member moving device 113, and the shielding member position detection sensor 114, and the wind generated by the blower fan 111 is It is adapted to be applied to the shielding member 112 having the feature of the form.

  As shown in FIG. 10, the shielding member 112 is composed of equipment 201, titanium oxide fine particles 202, and titanium oxide amorphous 203. The blower fan 111 generates an amount of air necessary for generating a catalytic action on the shielding member 112. The wind catalyst material is obtained by amorphizing titanium oxide or the like into a fine particle gel or sol, and utilizing a principle that electrons are generated when a magnetic field is generated by wind and pressure is applied. When electrons jump out, negative ions are generated on the same principle as the photocatalyst.

  In addition, when the wind catalyst substance is included in the shielding member 112, it is possible to simultaneously provide an active substance such as activated carbon or apatite. By using a wind catalyst material and such an adsorbent in combination, the adsorption capacity of the ozone product is increased and the decomposition capacity of the ozone product is also improved.

<Blower fan operation control>
FIG. 11 is a flowchart showing an operation control process of the blower fan 111 according to the present embodiment. A control program for realizing this processing is stored, for example, in a ROM in the control unit 40 and is executed by the CPU in the control unit 40.

  The blower fan 111 is driven to decompose the ozone product accumulated on the shielding member 112. The drive timing of the blower fan 111 is the same as the light irradiation timing according to the first embodiment. This is performed when the number of prints is reached, and is predicted when the time when ozone products are generated after the end of the print job and when the image forming apparatus is in the standby mode after that time has elapsed.

  In the operation control process of the blower fan 111 according to the present embodiment, the “light irradiation timing” described in the light irradiation process of FIG. 8 is changed to “fan driving timing” (step S311), and the “light emitting lamp 106” is changed to “fan blowing”. Only the fan 111 "(steps S313 and S315) is changed, and the processing procedure including the other processes (steps S312 and S314) is the same as the processing of FIG.

  Note that an object of the present invention is to supply a storage medium in which a program code of software for realizing the functions of the embodiment is recorded to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus as the storage medium. This can also be achieved by reading and executing the stored program code.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. -RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM, etc. can be used. Alternatively, the program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code. A case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.

  Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. This includes a case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  In this case, the program is supplied by downloading directly from a storage medium storing the program or from another computer or database (not shown) connected to the Internet, a commercial network, a local area network, or the like.

1 is a main part sectional view showing an overall configuration of an image forming apparatus according to a first embodiment; It is a schematic diagram which shows the peripheral part of a shielding apparatus. It is an external appearance perspective view which shows the example of 1 structure of a shielding apparatus. It is the schematic which shows the control system of the drum heater with which the inside of the photoconductive drum was equipped. 2 is a block diagram illustrating a schematic configuration of a control system of the image forming apparatus according to the first embodiment. FIG. It is a flowchart which shows the movement control process at the time of the power-on of the shielding member which concerns on 1st Embodiment. It is a flowchart which shows the movement control process at the time of the standby mode of the shielding member which concerns on 1st Embodiment. It is a flowchart which shows a light irradiation process. It is a schematic block diagram which shows the periphery of the primary charger which concerns on 2nd Embodiment. It is sectional drawing which shows the structure of the shielding member which concerns on 2nd Embodiment. It is a flowchart which shows the operation control process of a ventilation fan.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 7 Primary charger 40 Control part 103 Discharge wire 102,112 Shielding member 106 Light-emitting lamp 111 Blower fan 113 Shielding member moving apparatus 114 Shielding member position detection sensor 300 Drum heater

Claims (7)

A latent image based on an image signal is formed on the surface of the photosensitive member, a charging unit that charges the surface of the photosensitive member by discharge, and a charging unit that is charged by the charging unit to form the latent image on the photosensitive member. In an image forming apparatus, the image forming apparatus includes at least two standby modes of a standby mode and an energy saving mode in which power consumption is lower than the standby mode.
Heating means for warming the photoreceptor;
A shielding member for shielding between the photosensitive member and the charging unit;
A moving unit that moves the shielding member to a shielding position that shields between the charging unit and the photoconductor, and a retreat position that opens between the charging unit and the photoconductor;
An image forming apparatus comprising: the heat generating means and a control means for controlling the moving means so that the heat generating means is turned off and the shielding means is moved to the shielding position in the energy saving mode. . The shielding member has a photocatalytic substance that decomposes a discharge product generated by discharge of the charging unit,
Furthermore, a light irradiation means for irradiating the shielding member with light having a wavelength component that excites the photocatalytic substance,
The image forming apparatus according to claim 1, further comprising: a light irradiation control unit configured to irradiate the shielding member with light by the light irradiation unit when the shielding member is in the retracted position.   The image forming apparatus according to claim 2, wherein the light irradiation control unit controls the light irradiation unit to turn off after being irradiated for a predetermined time. The shielding member is configured to have a catalytic material that is excited by receiving air as a catalytic material for decomposing a discharge product generated by the discharge of the charging unit,
Furthermore, a blowing unit that applies a wind for exciting the catalytic substance to the shielding member;
The image forming apparatus according to claim 1, further comprising: an air blowing control unit that applies air to the shielding member by the air blowing unit when the shielding member is in the retracted position.   The image forming apparatus according to claim 4, wherein the air blowing control unit controls the air blowing unit to be turned off after being driven for a predetermined time.   The image forming apparatus according to claim 1, wherein the moving unit moves the shielding member to the retracted position when the image forming apparatus is powered on. A latent image based on an image signal is formed on the surface of the photosensitive member, a charging unit that charges the surface of the photosensitive member by discharge, and a charging unit that is charged by the charging unit to form the latent image on the photosensitive member. An image forming method of an image forming apparatus comprising: an exposure unit that exposes the surface of the photosensitive member, and having at least two standby modes of a standby mode and an energy saving mode that consumes less power than the standby mode;
Heat generating means for warming the photosensitive member, a shielding member for shielding between the photosensitive member and the charging means, a shielding position for shielding between the charging means and the photosensitive member, and the charging means and the photosensitive member. A moving means for moving the shielding member is provided in advance at a retracted position that opens between the body,
An image forming method for an image forming apparatus, wherein, in the energy saving mode, the heat generating means and the moving means are controlled so that the heat generating means is turned off and the shielding means is moved to the shielding position.

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