JP2010186143A - Image forming apparatus and shutter mechanism used for the image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize an image forming apparatus by constituting so that a moving amount of a shielding part is decreased. <P>SOLUTION: The image forming apparatus includes: the shielding part 7 provided in space between surfaces of a plurality of reading parts 12 and 13 and a surface of a developer carrier 2, having a fulcrum 7a for pivotally supporting the shielding part itself at one point on a position between any two reading parts out of the plurality of reading parts, and setting the reading part to either a shielding state or an open state by turning in the space centering around the fulcrum; a driving means 11 turning the shielding part; and a plurality of cleaning means 9 and 10 each provided in the shielding part so as to be opposed to the surface of each of the plurality of reading parts, and coming into contact with the surface of the reading part to which each cleaning means is opposed with turning of the shielding part, thereby removing an adhesive matter from the surfaces of the plurality of reading parts. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to a shutter mechanism used in the image forming apparatus.

In an electrophotographic color image forming apparatus (hereinafter simply referred to as “image forming apparatus”), a plurality of sensors are provided below the transfer belt, which is a developer image carrier. For example, when performing calibration (adjusting the sensitivity of the circuit), the plurality of sensors detect color misregistration (that is, the color of each color) based on the color misregistration detection pattern image (toner image) transferred to the surface of the transfer belt. It is used to detect a positional deviation between toner images) or to detect a density based on a density detection pattern image (toner image).
Each sensor is provided below the transfer belt such that a light emitting surface and a light receiving surface (hereinafter collectively referred to as “surface”) face the surface of the transfer belt. For example, deposits such as toner, dust, and dust adhere to the transfer belt, and these deposits often fall from the transfer belt. Therefore, in each sensor, deposits dropped from the transfer belt are easily collected on the surface, and the surface is particularly easily contaminated.

  Each sensor cannot perform normal detection if its surface (especially, the light receiving surface) becomes dirty. Therefore, in many image forming apparatuses, a mechanism for suppressing contamination on the surface of the sensor (hereinafter referred to as “suppression mechanism”) and a mechanism for cleaning the surface of the sensor (hereinafter referred to as “cleaning mechanism”). Is provided.

  As the suppression mechanism, for example, there is a configuration in which the surface of the sensor is shielded by a shielding part (shutter) at normal time (when calibration is not executed). In this configuration, the shutter is provided between the surface of each sensor and the surface of the transfer belt so as to freely slide in parallel with the surface of the transfer belt. The shutter is normally closed to shield the sensor surface from the transfer belt while the shutter is open to expose the sensor surface to the transfer belt during calibration.

On the other hand, as a cleaning mechanism, for example, Patent Document 1 discloses two configurations.
That is, in Patent Document 1, as “Embodiment 1”, a plurality of cleaning means (specifically, a film and a blade formed of an elastic member) are attached to the shutter of the above-described suppression mechanism. Discloses a mechanism in which a plurality of cleaning means clean the surfaces of sensors facing each other by sliding and moving parallel to the surface of the transfer belt.
Further, in Patent Document 1, as “Embodiment 2”, a plurality of cleaning means (film and blade) are attached to a shutter, and the shutter is provided with a fulcrum portion serving as a center of rotation. And a mechanism that cleans the surface of the sensor facing each of the plurality of cleaning means by rotating the shutter so as to form a three-dimensional arc around a fulcrum provided on the support column. It is disclosed.

  In each of the two cleaning mechanisms disclosed in Patent Document 1, each cleaning means is provided at a position facing the surface of each sensor, and each cleaning means rubs the surface of each sensor as the shutter moves. (Rub. Thereby, each cleaning mechanism removes dirt from the surface of each sensor and cleans the surface of each sensor.

JP 2006-208645 A

  Both of the two cleaning mechanisms disclosed in Patent Document 1 need to largely move the shielding unit so that the sensor having the largest surface area can be cleaned when cleaning a plurality of sensors having different surface areas. There is. For this reason, both of the two cleaning mechanisms require a space for greatly moving the shielding portion in the apparatus, which causes a problem that miniaturization of the image forming apparatus is hindered.

  The present invention has been made to solve the above-described problems, and an image forming apparatus in which the moving amount of the shielding portion is reduced and the image forming apparatus so as to realize downsizing of the image forming apparatus. It is a main object to provide an applicable shutter mechanism.

  In order to achieve the above object, the first invention is an image forming apparatus, comprising a developer image carrier that carries a developer image, each facing the developer carrier, and the development A plurality of reading units for reading the developer images carried on the developer carrier, and a space between the plurality of reading units and the developer carrier, and a plurality of the reading units. A fulcrum part that pivotally supports itself at one point at a position between any two of the reading parts, and by rotating in the space around the fulcrum part, a plurality of the reading parts are A shielding portion that is in one of a shielding state and an open state; a driving unit that rotates the shielding portion; and each of the plurality of reading units is provided on the shielding portion so as to face each other, and As the shielding part rotates, it comes into contact with the reading parts facing each other. By, for removing deposits from the plurality of the reading unit, configured to have a plurality of cleaning means.

  The second invention is a shutter mechanism used in an image forming apparatus having a function of forming a developer image on the surface of the developer carrying member, each of which is provided facing the surface of the developer carrying member, And provided in a space between a plurality of reading units for reading the developer image carried on the developer carrying member, a surface of the plurality of reading units and the surface of the developer carrying member, In addition, a fulcrum portion that pivotally supports itself at one point is provided at a position between any two reading portions of the plurality of reading portions, and rotates within the space around the fulcrum portion. Accordingly, a shielding unit that blocks or opens the plurality of reading units, a driving unit that rotates the shielding unit, and a surface of each of the plurality of reading units are opposed to each other. It was provided in the shielding part, and the shielding part was turned. I, by contacting the reading portion of the surface of each opposed to remove deposits from the surface of the plurality of the reading unit, configured to have a plurality of cleaning means.

  In the image forming apparatus according to the first invention and the shutter mechanism according to the second invention, the shielding part includes a fulcrum part at a position between any two reading parts. This fulcrum part pivotally supports the shielding part at one point. The shielding unit rotates in the space between the plurality of reading units and the developer carrier with the fulcrum portion as the center. In such a configuration, the shielding part is divided into a part on one end side and a part on the other end side around the fulcrum part, and the part on one end side and the part on the other end side each draw an arc. It moves to. At this time, the part on the one end side and the part on the other end side move by the width of the reading unit to be cleaned. Therefore, a portion deviating from the arc drawn by the shielding portion (that is, a portion not covered by the shielding portion) appears between the two reading units. Therefore, the image forming apparatus of the first invention and the shutter mechanism of the second invention are an apparatus and a mechanism in which the moving amount of the shielding portion is reduced.

  According to the present invention, it is possible to provide an image forming apparatus in which the moving amount of the shielding portion is reduced. Therefore, it is possible to reduce the size of the image forming apparatus.

1 is a cross-sectional view of an image forming apparatus according to Embodiment 1. FIG. FIG. 3 is a perspective view illustrating a configuration in a closed state of the shutter mechanism according to the first embodiment. FIG. 3 is a rear view illustrating the configuration of the shutter mechanism according to the first embodiment in a closed state. FIG. 3 is a perspective view illustrating a configuration of the shutter mechanism according to the first embodiment in an open state. FIG. 3 is a rear view illustrating the configuration of the shutter mechanism according to the first embodiment in an open state. FIG. 3 is a perspective view illustrating an exploded configuration of the shutter mechanism according to the first embodiment. FIG. 3 is a rear view illustrating a disassembled configuration of the shutter mechanism according to the first embodiment. It is explanatory drawing of the position of the fulcrum part of a shutter. FIG. 6 is a perspective view illustrating a configuration in a closed state of a shutter mechanism according to a second embodiment. FIG. 6 is a perspective view illustrating a configuration of an open state of a shutter mechanism according to a second embodiment. FIG. 6 is an exploded view of a main part of a shutter mechanism according to Embodiment 2. FIG. 10 is a plan view showing the operation of the main part of the shutter mechanism according to Embodiment 2. It is explanatory drawing (1) of the effect of the shutter mechanism which concerns on Embodiment 1. FIG. It is explanatory drawing (2) of the effect of the shutter mechanism which concerns on Embodiment 1. FIG. It is explanatory drawing (3) of the effect of the shutter mechanism which concerns on Embodiment 1. FIG.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings. Each drawing merely schematically shows the shape, size, and arrangement relationship of each component to the extent that the present invention can be understood. Therefore, the present invention is not limited to the illustrated example. Moreover, in each figure, the same code | symbol is attached | subjected about the common component and the same component, and those overlapping description is abbreviate | omitted.

[Embodiment 1]
Here, the overall configuration of the image forming apparatus according to the first embodiment will be described first, followed by the configuration of the shutter mechanism that is a characteristic component of the first embodiment, and finally the shutter. The operation of the mechanism will be described.

<Configuration of image forming apparatus>
The overall configuration of the image forming apparatus according to the first embodiment will be described below with reference to FIG. FIG. 1 is a cross-sectional view of the image forming apparatus according to the first embodiment. FIG. 1 schematically shows an arrangement relationship of main components of the image forming apparatus. Here, the configuration of the image forming apparatus will be described using a color electrophotographic printer (hereinafter simply referred to as “printer”).

  As shown in FIG. 1, a printer 100 is provided with a paper cassette 3a for containing paper, and in the vicinity thereof, a paper feed unit 3 and a paper travel path (hereinafter simply referred to as “travel path”). ) 4 is provided. The paper feed unit 3 includes a paper feed roller and an auxiliary roller. The paper feed unit 3 is driven to rotate by a paper feed motor (not shown), and feeds the paper stored in the paper cassette 3 a to the travel path 4. The sheet sent to the traveling path 4 is conveyed to the transfer belt 2 by the sheet conveying units 4a and 4b.

  The transfer belt 2 is a developer image carrier on which a sheet is conveyed in a normal state and a developer image (toner image) formed with toner as a developer is transferred to the surface during calibration. The transfer belt 2 is formed as an endless belt and is stretched between a pair of rollers. The transfer belt 2 is provided with four image forming units 5 along the paper conveyance direction.

  The image forming unit 5 is a component that forms a toner image. Each of the four image forming units 5 includes a photosensitive drum, a charging roller, an LED head, a developing unit, and a transfer roller.

The charging roller is a component that uniformly charges the surface of the photosensitive drum.
The LED head is a component that selectively exposes a uniformly charged photosensitive layer of a photosensitive drum according to image information. In the photosensitive layer of the photosensitive drum, the charged portion is removed from the exposed portion, while the charged portion remains in the unexposed portion to form an electrostatic latent image.
The developing unit is a component that forms a toner image by attaching toner to the electrostatic latent image on the photosensitive drum.
The transfer roller is a component that transfers the toner image formed on the surface of the photosensitive drum to the paper or the transfer belt 2 by applying a charge having a polarity opposite to that of the toner from the back surface of the transfer belt 2.

  The charging roller, the LED head, and the developing unit of each image forming unit 5 are provided above the transfer belt 2 so as to surround the photosensitive drum. In addition, the transfer roller of each image forming unit 5 is provided inside the transfer belt 2 so as to sandwich the transfer belt 2 with the photosensitive drum. Therefore, the transfer belt 2 is sandwiched between the photosensitive drum and the transfer roller of each image forming unit 5.

  Each of the four image forming units 5 has the same configuration, but contains toners of different colors (black, yellow, magenta, and cyan) in the developing unit.

The sheet conveyed to the transfer belt 2 is conveyed to the fixing unit 6 by the transfer belt 2. At that time, the toner image of each color is transferred onto the surface of the sheet by the four image forming units 5.
The fixing unit 6 is a component that fixes the toner image transferred on the surface of the paper to the paper. The fixing unit 6 includes a fixing roller with a built-in heater and a press roller. The fixing unit 6 heats and pressurizes the sheet by sandwiching the sheet between the fixing roller and the press roller, thereby fixing the toner image on the sheet.
The sheet on which the toner image has been fixed by the fixing unit 6 is conveyed to a discharge unit provided at the upper part of the printer 100 by the sheet transfer units 4c and 4d, and is collected in the discharge unit.

  Meanwhile, one of the pair of rollers around which the transfer belt 2 is stretched is a belt driving roller that is driven to rotate by a motor (not shown) to run the transfer belt 2. In the illustrated example, the left roller is a belt driving roller. The belt driving roller is rotationally driven in the direction of arrow R1 shown in FIG. 1 to cause the transfer belt 2 to travel in the direction of arrow R1.

  A sensor unit 1 is provided below the belt drive roller so as to face the surface of the transfer belt 2. The sensor unit 1 is a reading mechanism that optically reads a color misregistration detection pattern image and a density detection pattern image transferred to the surface of a transfer belt 2 that is a developer image carrier.

  The sensor unit 1 has a plurality of optical sensors (hereinafter simply referred to as “sensors”) as a reading unit (see FIG. 4). Each of the plurality of sensors includes a light emitting element and a light receiving element. The light emitting element irradiates light to both or one of the color misregistration detection pattern image and the density detection pattern image formed on the transfer belt 2. The light receiving element detects reflected light reflected by the pattern image and outputs a voltage signal corresponding to the intensity of the reflected light.

  In the example illustrated in FIG. 4, the sensor unit 1 includes two sensors 12 and 13 as reading units. Hereinafter, when the sensors 12 and 13 are distinguished, the sensor 12 is referred to as a “first sensor 12” and the sensor 13 is referred to as a “second sensor 13”. The first sensor 12 is a reading unit for detecting both color shift and density. The second sensor 13 is a reading unit for detecting the density. The area of the surface of the first sensor 12 is larger than the area of the surface of the second sensor 13 (see FIG. 13B). Note that the sensor unit 1 may be configured to include another sensor between the sensor 12 and the sensor 13.

  The sensor unit 1 is provided with a shutter mechanism 105 (see FIG. 2) that is a characteristic component of the first embodiment. The shutter mechanism 105 is configured to serve as both a shielding mechanism for the surfaces of the sensors 12 and 13 and a cleaning mechanism.

<Configuration of shutter mechanism>
The configuration of the shutter mechanism will be described below with reference to FIGS. 2 is a perspective view showing a configuration of the shutter mechanism according to the first embodiment in a closed state, and FIG. 3 is a rear view thereof. 4 is a perspective view showing a configuration of the shutter mechanism according to the first embodiment in an open state, and FIG. 5 is a rear view thereof. 6 is a perspective view showing an exploded configuration of the shutter mechanism according to the first embodiment, and FIG. 7 is a rear view thereof.

  As shown in FIGS. 2 to 7 (particularly, FIG. 6), the shutter mechanism 105 is attached in a state where the bracket 8 is fixed on the base plate 19. The bracket 8 is a support part for attaching various components. The base plate 19 is a base part of the shutter mechanism 105.

  As shown in FIG. 6, the bracket 8 is attached in a state where a plurality of sensors (here, the first sensor 12 and the second sensor 13) are fixed to a surface facing the transfer belt 2 (see FIG. 1). It has been. The second sensor 13 has a sensor cover 14 attached to the surface. The sensor cover 14 is a member for protecting the surface of the second sensor 13 and is made of a material such as transparent plastic.

  The bracket 8 is fixed to the rear side of the first sensor 12 in the rotation direction of the shutter 7 described later (that is, in the direction of the arrow AR2 shown in FIG. 4) where the guide plate 16 faces the transfer belt 2. It is attached with. The guide plate 16 is a member for guiding the rotation of the shutter 7 and constitutes the same flat surface as the surface of the first sensor 12.

  The bracket 8 is attached in a state where the solenoid 11 is fixed to the surface facing the transfer belt 2. The solenoid 11 is a driving means for rotating the shutter 7. The solenoid 11 is controlled by a control unit (not shown) that controls the entire printer 100. As shown in FIG. 5, the solenoid 11 is engaged with a groove portion 7 d provided in the shutter 7 via a pin 18, and transmits driving force to the shutter 7 via this pin 18.

  Further, the bracket 8 is provided on a surface where the post 8 a faces the transfer belt 2. The post 8a is a component for rotatably supporting the shutter 7. The post 8a is configured as a columnar protrusion protruding in the vertical direction toward the transfer belt 2 side.

  The bracket 8 is attached to the surface of the torsion spring 15 facing the transfer belt 2 so that the post 8a penetrates the winding body of the torsion spring 15. The torsion spring 15 is a member for urging the shutter 7 in the direction of the arrow AR1 shown in FIG.

  Further, the bracket 8 is attached to a surface where the shutter 7 faces the transfer belt 2 so that the post 8a penetrates a fulcrum portion 7a described later.

  The shutter 7 is a shielding part for shielding the surface of each of a plurality of sensors (here, the first sensor 12 and the second sensor 13). The shutter 7 is configured as a long plate having a length and a width that can cover the surface of each sensor. The shutter 7 is provided in a space between the surface of the transfer belt 2 and the surfaces of the sensors 12 and 13. The shutter 7 has one end facing the first sensor 12 and the other end facing the second sensor 13.

  The shutter 7 is provided between a portion where the fulcrum portion 7 a faces the first sensor 12 and a portion facing the second sensor 13. The fulcrum portion 7a is a circular hole formed in the shutter 7, and the post 8a of the bracket 8 is fitted into the hole. The shutter 7 is driven by a solenoid 11 and rotates in a space between the surface of the transfer belt 2 and the surfaces of the sensors 12 and 13 around the fulcrum portion 7a. The fulcrum part 7 a is provided perpendicular to the surfaces of the sensors 12 and 13 so that the shutter 7 rotates in parallel with the surfaces of the sensors 12 and 13. The fulcrum part 7a is preferably provided at a position that can satisfy a stroke necessary for cleaning a plurality of sensors (here, the first sensor 12 and the second sensor 13) having different widths. The position of the fulcrum portion 7a (that is, the position of the post 8a) will be described later with reference to FIG.

  The amount of movement (here, rotation) of the shutter 7 is regulated by the bracket 17. The bracket 17 is a member for regulating the movement amount of the shutter 7. The bracket 17 is fixed from above the shutter 7 in the vicinity of the end of the shutter 7 on the surface facing the transfer belt 2 of the bracket 8 (in the illustrated example, one end where the first sensor 12 is provided). It is attached with.

  The shutter 7 is provided with cleaning means at positions facing the respective surfaces of the plurality of sensors (here, the first sensor 12 and the second sensor 13). In the illustrated example, the shutter 7 is provided with a film 9 (see FIG. 2) as a first cleaning means at a portion facing the first sensor 12 on one end side, and further as a second cleaning means. The blade 10 (see FIG. 3) is provided in a portion facing the second sensor 13 on the other end side. The film 9 is a cleaning member formed in a film shape by a material such as polyester having elasticity. The film 9 is disposed so as to cover the entire surface of the portion of the shutter 7 that faces the first sensor 12, and is fixed to the shutter 7 by attachment means such as an adhesive, a double-sided tape, or a snap. On the other hand, the blade 10 is a cleaning member formed in a tongue shape by a material such as elastic silicon rubber. The blade 10 is disposed so that the lower end of the tongue is in contact with the entire surface of the second sensor 13 of the shutter 7, and the upper end of the tongue is fixed to the shutter 7 by an attaching means such as an adhesive, a double-sided tape or a snap. Yes. Here, the film 9 is used as the first cleaning means, and the blade 10 is used as the second cleaning means. However, the first cleaning means and the second cleaning means are films, blades, and others. It can be used by appropriately selecting from the cleaning members.

  The shutter 7 is always urged in the direction of the arrow AR1 shown in FIG. 2 by the urging force of the torsion spring 15. Therefore, the shutter 7 (see FIG. 2) is closed during normal times (when calibration is not performed), and shields the surfaces of the sensors 12 and 13 from the transfer belt 2 (see FIGS. 2 and 3). .

  Further, the shutter 7 is rotated in the space between the transfer belt 2 and the sensors 12 and 13 in the direction of the arrow AR2 shown in FIG. Is done. Therefore, the shutter 7 is in an open state when the calibration is executed, and exposes the surfaces of the sensors 12 and 13 to the transfer belt 2 (see FIGS. 4 and 5). The shutter 7 stops rotating when the end portions 7 b and 7 c (see FIG. 6) abut against the limiter portions 17 a and 17 b of the bracket 17.

  The first cleaning means (film 9) and the second cleaning means (blade 10) provided on the shutter 7 rotate according to the rotation of the shutter 7 during the calibration. By this rotation, the film 9 and the blade 10 come into contact with the surfaces of the sensors 12 and 13 to rub (rub) the surfaces of the sensors 12 and 13. Accordingly, the film 9 and the blade 10 remove dirt from the surfaces of the sensors 12 and 13 and clean the surfaces of the sensors 12 and 13.

  Note that the solenoid 11 is normally configured such that the movement amount of the pin 18 is constant, so that the shutter 7 is rotated only a certain amount. Therefore, the position of the fulcrum portion 7a of the shutter 7 (that is, the position of the post 8a of the bracket 8) is the first sensor 12 and the second sensor in the rotation direction of the shutter 7 (the direction of the arrow AR2 shown in FIG. 8). Preferably, the sensor cover 14 covering 13 is in a position that satisfies the rotation angles θ1 and θ2 (see FIG. 8) determined from the difference in width of the area (hereinafter referred to as “cleaning area”) where the sensor cover 14 is cleaned. FIG. 8 is an explanatory diagram of the position of the fulcrum portion of the shutter. In the first embodiment, as shown in FIG. 8, the “width of the cleaning region” includes the width W2 of the ridge line 12a on the fulcrum part 7a side of the first sensor 12 and the ridge line on the fulcrum part 7a side of the second sensor 13. The width W1 is 13a.

  Specifically, the position of the fulcrum portion 7a of the shutter 7 (that is, the position of the post 8a of the bracket 8) is, for example, an arbitrary position of the ridge line 12a and an arbitrary position of the ridge line 13a when the number of sensors is two. The distance from the ridge line 12a to the fulcrum portion 7a is L2 on the straight line connecting the positions of the ridge lines 12a (specifically, the midpoint of the ridgeline 12a and the midpoint of the ridgeline 13a), and the ridgeline 13a When the distance from the fulcrum part 7a to the fulcrum part 7a is L1, it is a position having a relationship of θ1: θ2 = L1: L2.

  Alternatively, the position of the fulcrum portion 7a of the shutter 7 may be preferably determined by the following simple method. That is, the position of the fulcrum part 7a of the shutter 7 is set such that two sensors provided at positions closest to both side surfaces of the printer 100 main body among the plurality of sensors are respectively sensors on one end side (here, the first sensor 12). ) And the sensor on the other end side (herein, the second sensor 13), the position between the first sensor 12 and the second sensor 13 and the rotation direction of the shutter 7 (see FIG. 8 (in the direction of arrow AR2), the position may correspond to the ratio between the maximum length W2 of the first sensor 12 and the maximum length W1 of the second sensor 13. Since this method has a relationship of W1: W2 = L1: L2, this method also satisfies the relationship of θ1: θ2 = L1: L2. This approach is particularly preferred when the number of sensors is greater than two.

<Operation of shutter mechanism>
Hereinafter, the operation of the shutter mechanism will be described with reference to FIG. When the power is turned on, the printer 100 performs the following operation based on control of a control unit (not shown).

  That is, the printer 100 first runs the transfer belt 2 in the direction of the arrow R1 shown in FIG. 1 by a drive system (not shown), and a color misregistration detection pattern image and a density detection pattern in accordance with this rotation. The image is transferred onto the transfer belt 2.

  Next, the printer 100 energizes the solenoid 11 to rotate the shutter 7 in the direction of the arrow AR2 shown in FIG. At this time, the shutter 7 has a portion at one end (that is, a portion where the film 9 facing the first sensor 12 is present) and a portion at the other end (that is, the second sensor 13) around the fulcrum portion 7 a. And a portion on one end side and a portion on the other end side move so as to draw an arc.

When the shutter 7 rotates, the film 9 rubs the surface of the sensor 12, and the blade 10 rubs the surface of the sensor cover 14 that covers the sensor 13. Thereby, the surfaces of the sensor 12 and the sensor cover 14 are cleaned.
The shutter 7 rotates in a plane parallel to the surfaces of the sensors 12 and 13. Therefore, the film 9 and the blade 10 provided on the shutter 7 are in contact with the entire surfaces of the sensor 12 and the sensor cover 14 with a uniform pressing force. Thereby, the film 9 and the blade 10 can clean the entire surface of the sensor 12 and the sensor cover 14 without unevenness (unevenness).

The shutter 7 stops when the end portion 7 b (see FIG. 6) abuts on the limiter portion 17 a of the bracket 17.
At this time, the film 9 provided on the shutter 7 passes over the surface of the first sensor 12 and stops on the guide plate 16 as shown in FIG. On the other hand, the blade 10 provided in the shutter 7 is stationary on the end portion 14a of the sensor cover 14, as shown in FIG.

  In this state, the printer 100 reads the color misalignment detection pattern image and the density detection pattern image transferred onto the transfer belt 2 by the first sensor 12 and the second sensor 13.

When the reading is completed, the printer 100 cuts off the energization of the solenoid 11. At this time, the shutter 7 is rotated in the direction of the arrow AR1 shown in FIG. 2 by the urging force of the torsion spring 15. The shutter 7 stops when the end 7c (see FIG. 6) abuts against the limiter 17b of the bracket 17.
At this time, the shutter 7 covers the surface of the first sensor 12 and the surface of the sensor cover 14 as shown in FIG. Thereafter, the shutter 7 covers the surfaces of the first sensor 12 and the sensor cover 14, and prevents the toner from dropping and collecting on the first sensor 12 and the sensor cover 14.

  Hereinafter, with reference to FIGS. 13 to 15, regarding the effects of the shutter mechanism 105 according to the first embodiment, the shutter mechanism 105 and a shutter mechanism 106 (see FIG. 14A) as a comparative example having the following configuration, for example, This will be explained by comparing. Here, the shutter mechanism 106 as a comparative example has the same shape as the shutter 7 according to the first embodiment and the first cleaning means (film 9) and the second cleaning means at the same position as the shutter 7. It is assumed that the shutter 70 having the (blade 10) is included. However, unlike the shutter 7 of the first embodiment, the shutter 70 of the comparative example is configured to linearly move in the short direction of the sensors 12 and 13 facing the film 9 and the blade 10.

  13 to 15 are explanatory diagrams of the effect of the shutter mechanism according to the first embodiment. FIG. 13 schematically shows the amount of movement of the shutter 7 of the shutter mechanism 105 according to the first embodiment. 13A shows a schematic configuration of the shutter 7 viewed from above, and FIG. 13B shows the movement area S1 of the shutter 7 and the sensors 12 to be cleaned. The state where the position of 13 is overlapped is shown. In FIG. 13A, the shutter 7 is schematically shown as a line so that the moving area S1 of the shutter 7 shown in FIG. On the other hand, FIG. 14 schematically shows a moving amount of the shutter 70 of the shutter mechanism 106 when the shutter 70 is moved in the short direction of the sensors 12 and 13 as a comparative example. 14A shows a schematic configuration of the shutter 7 as viewed from above, and FIG. 14B shows the moving area S2 of the shutter 70 and the sensors 12 to be cleaned. The state where the position of 13 is overlapped is shown. In FIG. 14A, the shutter 70 is schematically shown as a line so that the moving area S2 of the shutter 70 shown in FIG. 14B becomes clear. FIG. 15 shows a state in which the moving area S1 of the shutter 7 of the first embodiment shown in FIG. 13B and the moving area S2 of the shutter 70 of the comparative example shown in FIG. 14B are overlapped. .

  Here, the shutter 7 of the first embodiment and the shutter 70 of the comparative example will be described as configured as follows. Here, both the shutter 7 and the shutter 70 are driven by a single solenoid 11 (see FIG. 3).

  That is, the shutter 7 of the first embodiment and the shutter 70 of the comparative example are both the outer ends of the first sensor 12 as shown in FIGS. 13A and 14A. And the outer end of the second sensor 13 (X1 + L1 + L2 + X2), and the first cleaning means (film 9) is provided at a position facing the first sensor 12, and The second cleaning means (blade 10) is provided at a position facing the second sensor 13.

  Both the shutter 7 and the shutter 70 have a distance L1 from the second sensor 13 to the center of the fulcrum part 7a (not present in FIG. 4B), and from the center of the fulcrum part 7a. The distance to the first sensor 12 is L2. Therefore, the distance from the second sensor 13 to the first sensor 12 is (L1 + L2).

  As shown in FIGS. 13B, 14B, and 15, the second sensor 13 has a length in the X-axis direction of X1, and a length in the Y-axis direction. W1. The first sensor 12 has a length in the X-axis direction of X2, and a length in the Y-axis direction of W2.

The second sensor 13 has a plurality of lenses 131. The plurality of lenses 131 correspond to the light emitting unit and the light receiving unit of the second sensor 13, respectively, and are arranged in a line near the center of the second sensor 13 in the length W1 in the Y-axis direction.
Similarly, the first sensor 12 also has a plurality of lenses 121. The plurality of lenses 121 correspond to the light emitting unit and the light receiving unit of the first sensor 12, respectively, and are arranged in a line near the center of the first sensor 12 in the length W2 in the Y-axis direction.

The shutter 7 according to the first embodiment rotates around the fulcrum portion 7a. FIG. 13B shows the movement amount of the shutter 7 as a movement area S1.
In contrast, the shutter 70 of the comparative example moves linearly in the short direction of the sensors 12 and 13 (that is, the Y-axis direction shown in FIG. 14B). FIG. 14B shows the moving amount of the shutter 70 of the comparative example as a moving area S2.

  In the shutter 7 of the first embodiment and the shutter 70 of the comparative example, the total sum of the cleaning areas of the sensors 12 and 13 to be cleaned is the same ((W1 × L1) + (W2 × L2)). .

  The moving area S1 of the shutter 7 according to the first embodiment is S1 = (S11 + S12) as shown in FIG. 13B. S11 is a movement area of the portion from the outer end of the portion of the shutter 7 facing the second sensor 13 to the center of the fulcrum portion 7a, and S12 is the first from the center of the fulcrum portion 7a of the shutter 7. 2 is a movement area of a portion up to an outer end of a portion facing the sensor 13. The moving area S1 of the shutter 7 is determined from the relationship between the rotation angles θ1 and θ2 (see FIG. 8) of the shutter 7 and the position of the fulcrum portion 7a. In addition, it is preferable that the position of the fulcrum part 7a is a position having a relationship of θ1: θ2 = L1: L2, as described above. Here, the position of the fulcrum part 7a is assumed to be a position corresponding to the ratio of the length W2 of the first sensor 12 in the Y-axis direction and the length W1 of the second sensor 13 in the Y-axis direction.

  On the other hand, the moving area S2 of the shutter 70 of the comparative example is S2 = (L1 + L2 + X1 + X2) × W2, as shown in FIG. 14B. That is, the moving area S2 of the shutter 70 is the distance (L1 + L2) from the second sensor 13 to the first sensor 12, the length X1 of the second sensor 13 in the X-axis direction, and the X-axis of the first sensor 12. The maximum width of the first sensor 12 and the second sensor 13 in the Y-axis direction (here, the width of the first sensor 12 in the Y-axis direction), which is a value obtained by adding the length X2 in the direction (L1 + L2 + X1 + X2) The area multiplied by W2). The moving area S2 of the shutter 70 is determined from the relationship between the X-axis direction width (X1 + L1 + L2 + X2) of the shutter 70 and the Y-axis direction moving distance.

As shown in FIG. 15, it is clear that the moving area S1 of the shutter 7 of the first embodiment and the moving area S2 of the shutter 70 of the comparative example satisfy S1 <S2.
Therefore, the shutter mechanism 105 according to the first embodiment can reduce the movement amount of the shutter 7 compared to the shutter mechanism 106 (see FIG. 14) of the comparative example.

  Further, as will be described below, the shutter mechanism 105 according to the first embodiment reduces the amount of operation of the solenoid 11 compared to the shutter mechanism 106 of the comparative example by providing the solenoid 11 in the vicinity of the fulcrum portion 7a. it can.

  That is, in the shutter mechanism 106 of the comparative example, the solenoid 11 moves the shutter 70 linearly in the Y-axis direction. The shutter mechanism 106 needs to move the shutter 70 of the comparative example by the cleaning area of the first sensor 12 and the second sensor 13. Therefore, the operation amount of the solenoid 11 in the shutter mechanism 106 is the maximum width in the Y-axis direction of the first sensor 12 and the second sensor 13 (that is, the width W2 of the first sensor 12 in the Y-axis direction). .

On the other hand, in the shutter mechanism 105 according to the first embodiment, the solenoid 11 rotates the shutter 7 around the fulcrum portion 7a. In the shutter mechanism 105, the amount of operation of the solenoid 11 decreases as the position of the solenoid 11 approaches the fulcrum portion 7a that is the center of rotation. Therefore, the operation amount of the solenoid 11 in the shutter mechanism 105 is adjusted by moving the position of the solenoid 11 closer to the fulcrum portion 7a, so that the operation amount of the solenoid 11 in the shutter mechanism 106 (that is, the width W2 of the first sensor 12 in the Y-axis direction). Min)).
In the first embodiment, as shown in FIG. 5, the solenoid 11 is provided in the vicinity of the fulcrum part 7 a and is configured to be engaged with the groove part 7 d provided in the vicinity of the fulcrum part 7 a via the pin 18. It has become. Therefore, in the shutter mechanism 105 according to the first embodiment, the operation amount of the solenoid 11 is smaller than the operation amount of the solenoid 11 in the shutter mechanism 106 (that is, the width W2 of the first sensor 12 in the Y-axis direction). Yes.

  As described above, according to the shutter mechanism 105 according to the first embodiment, the shutter 7 has the fulcrum portion 7a at the position between the two sensors (here, the first sensor 12 and the second sensor 13). I have. The fulcrum part 7a pivotally supports the shutter 7 at one point. The shutter 7 rotates in the space between the surfaces of a plurality of sensors (here, the first sensor 12 and the second sensor 13) and the surface of the transfer belt 2 around the fulcrum portion 7a. . In such a configuration, the shutter 7 has a portion on one end (that is, a portion where the film 9 facing the first sensor 12 exists) and a portion on the other end (that is, the second portion) around the fulcrum portion 7a. The part on one end side and the part on the other end side move so as to draw a circular arc. At this time, the part on the one end side moves by the width W2 of the first sensor 12, and the part on the other end side moves by the width W1 of the second sensor 13. Therefore, a portion deviating from the arc drawn by the shutter 7 (that is, a portion not covered by the shutter 7) appears between the first sensor 12 and the second sensor 13. Therefore, according to the shutter mechanism 105 according to the first embodiment, the moving amount of the shutter 7 can be reduced. Therefore, a necessary space in the apparatus can be reduced, and thereby the apparatus can be reduced in size.

  Further, according to the shutter mechanism 105 according to the first embodiment, since the shutter 7 has only to be pivotally supported at one point, the mechanism for supporting the shutter 7 so as to be movable can be simplified. Therefore, this also makes it possible to reduce the size of the apparatus.

  Further, according to the shutter mechanism 105 according to the first embodiment, since the fulcrum portion 7a is provided so as to be perpendicular to the surfaces of the first sensor 12 and the second sensor 13, the shutter 7 is It can be rotated along the surfaces of the first sensor 12 and the second sensor 13, whereby the surfaces of the first sensor 12 and the second sensor 13 can be stably cleaned.

[Embodiment 2]
The shutter mechanism 105a according to the second embodiment is configured such that a plurality of cleaning units can clean a plurality of reading units having different reading directions.

  Hereinafter, the configuration of the shutter mechanism 105a of the image forming apparatus according to the second embodiment will be described with reference to FIGS. FIG. 9 is a perspective view illustrating a configuration of the shutter mechanism according to the second embodiment in a closed state. FIG. 10 is a perspective view illustrating a configuration of the shutter mechanism according to the second embodiment in an open state. FIG. 11 is an exploded view of the main part of the shutter mechanism according to the second embodiment, and FIG. 12 is a plan view showing the operation of the main part.

  As shown in FIGS. 9 to 12 (particularly, FIG. 11), the shutter mechanism 105a according to the second embodiment includes a sensor substrate 24 instead of the second sensor 13 of the shutter mechanism 105 according to the first embodiment. is doing. The sensor substrate 24 is a component on which one or more sensors (not shown) are mounted as a reading unit.

The sensor substrate 24 is mounted such that the sensor cover 25 covers the surface of one or more sensors. The sensor substrate 24 is a member for protecting one or more sensors and is made of a material such as transparent plastic.
The sensor substrate 24 is attached in a state of being fixed to the bracket 26 in a vertically standing state so that one or more sensors are opposed to the tip of the shutter 23. Thereby, the sensor cover 25 is attached in a state of being fixed to the bracket 26 so as to come into contact with the cleaning member portion 21c at a position facing a cleaning member 21c described later.

  The shutter 23 has a slider 21 attached to the tip. The slider 21 is a component that slides in the direction of the tip of the shutter 23 or in the opposite direction (the direction of the arrow AR4 shown in FIG. 12). As shown in FIG. 11B, the slider 21 has a pair of groove portions 21 a and 21 b provided on both sides of the rear end (that is, the end portion attached to the front end of the shutter 23). The slider 21 is attached to the tip of the shutter 23 so that the guide portion 23a (see FIG. 11) is fitted into the groove portions 21a and 21b. The guide portions 23a are a pair or a plurality of pairs (two pairs in the illustrated example) provided on both sides of the front end of the shutter 23. The groove portions 21a and 21b of the slider 21 and the guide portion 23a at the tip of the shutter 23 are provided in parallel along the direction of the arrow AR4 shown in FIG. 12 so as to be fitted to each other. The slider 21 is free to move in both directions (in the direction of the arrow AR4 shown in FIG. 12) in the direction opposite to the tip of the shutter 23 by fitting the grooves 21a and 21b of the slider 21 and the guide 23a at the tip of the shutter 23 to each other. Move to slide.

  As described above, the sensor substrate 24 is attached in a state of being fixed to the bracket 26 in a vertically standing state so that one or more sensors face the tip of the shutter 23. Accordingly, the slider 21 slides the tip of the shutter 23 in both directions so as to face the sensor substrate 24.

  The slider 21 is attached to the tip of the shutter 23 with the compression spring 22 sealed inside. Therefore, the slider 21 is always urged toward the front end side of the shutter 23 by the urging force of the compression spring 22.

The slider 21 has a cleaning member 21c attached to the tip. The cleaning member 21 c is a member for cleaning the surface of one or more sensors mounted on the sensor substrate 24. As with the film 9 and the blade 10, the cleaning member 21c is configured by a member such as polyester having elasticity or a member such as silicon rubber having elasticity. The cleaning member 21 c is provided with an angle with the rotation surface of the shutter 23 so as to face the sensor cover 25.
In the shutter mechanism 105a according to the second embodiment, the cleaning member 21c of the slider 21 rubs the surface of one or more sensors (here, the surface of the sensor cover 25 that covers the surface of the sensor) mounted on the sensor substrate 24. Thus, the surfaces of one or more sensors provided on the sensor substrate 24 are cleaned.

  Hereinafter, the operation of the shutter mechanism 105a according to the second embodiment will be described. Here, the operation different from the shutter mechanism 105 of the first embodiment will be described mainly, and the operation similar to the shutter mechanism 105 of the first embodiment is the same as the operation of the shutter mechanism 105 according to the first embodiment. The detailed description is omitted as a replacement for the shutter mechanism 105a according to the second embodiment.

  When the power is turned on, the printer 100 first runs the transfer belt 2 in the direction of the arrow R1 shown in FIG. 1 by a drive system (not shown) in the same manner as in the first embodiment, and in accordance with this rotation. Then, the color misregistration detection pattern image and the density detection pattern image are transferred onto the transfer belt 2. Next, the printer 100 energizes the solenoid 11 to rotate the shutter 23 of the shutter mechanism 105a in the direction of the arrow AR2 (see FIG. 4). The shutter 23 stops when the end portion 7 b (see FIG. 6) abuts on the limiter portion 17 a of the bracket 17.

  The slider 21 is initially stopped at a position where it abuts on the sensor cover 25, but slides in the direction of the distal end of the shutter 23 along the arrow AR4 shown in FIG. Then, the slider 21 stops at the end of the surface of the sensor cover 25 or at a position past the surface. As a result, the cleaning member portion 9 provided at the tip of the slider 21 rubs the surface of the sensor cover 25. At this time, the cleaning member 9 rubs the surface of the sensor cover 25 with an appropriate force by the urging force generated by the compression spring 22. Therefore, the shutter mechanism 105a can clean the surface of the sensor cover 25.

When the energization of the solenoid 11 is cut off, the printer 100 is returned to the position where the cleaning member portion 9 contacts the sensor cover 25 by the urging force of the torsion spring 15 (see FIG. 2), and stops at that position. Thereby, the shutter 105 a shields the surface of the sensor mounted on the sensor substrate 24 and also shields the surface of the first sensor 12.
The operation of the shutter 23 with respect to the first sensor 12 is the same as that of the shutter 7 of the first embodiment.

As described above, according to the shutter mechanism 105a of the second embodiment, the shutter 23 rotates about the fulcrum portion 7a as in the shutter mechanism 105 of the first embodiment. 14), the amount of movement of the shutter 23 can be reduced. Therefore, the required space in the apparatus can be reduced, and this enables downsizing of the apparatus.
Further, according to the shutter mechanism 105a according to the second embodiment, the shutter 23 only has to be pivotally supported at one point, similarly to the shutter mechanism 105 according to the first embodiment. Therefore, the mechanism that supports the shutter 23 in a movable manner is simplified. can do. Therefore, this also makes it possible to reduce the size of the apparatus.
Further, according to the shutter mechanism 105a of the second embodiment, the fulcrum portion 7a is provided so as to be perpendicular to the surface of the first sensor 12 as in the shutter mechanism 105 of the first embodiment. The surface of the first sensor 12 can be stably cleaned.
Furthermore, according to the shutter mechanism 105a of the second embodiment, a plurality of reading units having different reading directions such as the surface of the first sensor 12 and the surface of the sensor substrate 24 (here, the surface of the sensor cover 25) are provided. Can be cleaned at the same time.

The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the gist of the present invention.
For example, the present invention is not limited to a printer, and can be used in an image forming apparatus such as a copying machine, a FAX, and an MFP. Note that “MFP” is an abbreviation for Multi Function Printer (or Product), and is an apparatus in which a facsimile function, a scanner function, a copy function, and the like are added to a printer.

1 Sensor unit 2 Transfer belt (image carrier)
3 Paper Feeding Section 3a Paper Cassette 4 Paper Travel Path (Travel Path)
4a, 4b, 4c, 4d Paper transport unit 5 Image forming unit 6 Fixing unit 7, 23 Shutter (shielding unit)
7a fulcrum part 7b, 7c end part 7d groove part 8, 17, 26 bracket 8a post 9 film (first cleaning means)
10 Blade (second cleaning means)
11 Solenoid (drive means)
12, 13 Sensor 12a, 13a Edge line 14, 25 Sensor cover 14a End 15 Torsion spring 16 Guide plate 17a, 17b Limiter 18 Pin 19 Base plate 21 Slider 21a, 21b Groove 21c Cleaning member 22 Compression spring 23a Guide 24 24 Sensor substrate 100 Image forming device (printer, copier, FAX, MFP, etc.)
105, 105a Shutter mechanism

Claims (10)

A developer image carrier that carries a developer image;
A plurality of reading units, each of which is provided facing the surface of the developer carrying member, and reads the developer image carried on the developer carrying member;
One point is provided in a space between the surface of the plurality of reading units and the surface of the developer carrier, and at a position between any two reading units of the plurality of reading units. A shielding portion that pivots in the space with the fulcrum portion pivotally supported at the center, thereby turning the plurality of reading portions into a state of shielding or opening,
Driving means for rotating the shielding part;
Each of the plurality of reading units is provided on the shielding unit so as to face each surface of the plurality of reading units, and each of the plurality of reading units comes into contact with the surface of the reading unit facing each other as the shielding unit rotates. An image forming apparatus comprising: a plurality of cleaning means for removing deposits from the surface of the reading unit. The image forming apparatus according to claim 1,
The fulcrum part of the shielding part is
When two of the plurality of reading units provided at positions closest to both side surfaces of the apparatus main body are respectively a reading unit on one end side and a reading unit on the other end side,
The maximum length of the one end side reading unit and the maximum of the other end side reading unit at a position between the one end side reading unit and the other end side reading unit and in the rotation direction of the shielding unit. An image forming apparatus provided at a position corresponding to a ratio to a length. The image forming apparatus according to claim 1, wherein:
The amount of rotation of the shielding unit rotated by the driving unit is such that the amount of movement of the cleaning unit facing the reading unit on the one end side is the maximum length of the reading unit on the one end side in the rotation direction of the shielding unit. And the amount of movement of the cleaning means facing the reading unit on the other end side is set to an amount that becomes the maximum length of the reading unit on the other end side in the rotation direction of the shielding unit. An image forming apparatus. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the reading unit optically reads the developer image. The image forming apparatus according to claim 4.
The image forming apparatus, wherein the reading unit is a light receiving unit. The image forming apparatus according to claim 1, wherein:
The image forming apparatus according to claim 1, wherein the fulcrum portion supports the shielding portion in a direction perpendicular to a surface of the reading portion that faces the shielding portion. The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein the plurality of cleaning units can clean the plurality of reading units having different reading directions. The image forming apparatus according to claim 7.
At least one of the plurality of cleaning units is slidably provided at the front end of the shielding unit so as to face the surface of the reading unit disposed in a standing position. . The image forming apparatus according to claim 8.
And an urging member for urging the slidable cleaning unit in a direction toward the reading unit disposed in a standing position. In a shutter mechanism used in an image forming apparatus having a function of forming a developer image on the surface of a developer carrier,
A plurality of reading units, each of which is provided facing the surface of the developer carrying member, and reads the developer image carried on the developer carrying member;
One point is provided in a space between the surface of the plurality of reading units and the surface of the developer carrier, and at a position between any two reading units of the plurality of reading units. A shielding portion that pivots in the space with the fulcrum portion pivotally supported at the center, thereby turning the plurality of reading portions into a state of shielding or opening,
Driving means for rotating the shielding part;
Each of the plurality of reading units is provided on the shielding unit so as to face each surface of the plurality of reading units, and each of the plurality of reading units comes into contact with the surface of the reading unit facing each other as the shielding unit rotates. And a plurality of cleaning means for removing deposits from the surface of the reading unit.

Images