JP2010204530A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that always obtains a satisfactory image in any condition and excels in unit replacement and maintenance. <P>SOLUTION: The image forming apparatus is configured as described below. One face plate is rotatably provided to the housing. A holding mechanism is disposed between the photoreceptor unit and optical scanning device and the face plate. The face plate is rotatable between a holding position in which the photoreceptor unit and the optical scanning device are positioned and held by the holding mechanism, and a detaching position in which the photoreceptor unit and the optical scanning device are released from the hold and can be detached from the housing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus using an electrostatic copying process such as a copying machine, a facsimile machine, and a printer.

  In image forming apparatuses, generally, a latent image writing device such as a laser writing device that optically scans a laser beam onto a latent image carrier such as a photoconductor is widely used. .

  In such an image forming apparatus, the positional relationship between the latent image carrier such as a photoreceptor and the optical scanning device is extremely important. In order to obtain desired image quality and characteristics, these units are It is necessary to always position and hold at a predetermined position.

  If the mutual positional relationship between the photosensitive unit and the optical scanning device is deviated from a desired state, not only the skew on the image and the image position are deviated, but also the light beam to be exposed and scanned by the optical scanning device. The image characteristics are also deteriorated, causing remarkable image deterioration and image defect.

  Here, the desired positional relationship must always be maintained, not only in the initial state, but also after the photoconductor unit and the optical scanning device are replaced.

  In the image forming apparatus, the photosensitive unit provided in the apparatus and the optical scanning apparatus need to be replaced before reaching the lifetime of the apparatus itself, and the unit replacement and apparatus replacement at that time are easy. Of course it is required.

  Here, in Japanese Patent Application Laid-Open No. 2007-164128 (Patent Document 1), a technique for suppressing a decrease in writing position accuracy of the optical writing unit (optical scanning device) while improving the maintainability of the photosensitive unit and its peripheral devices. Has been proposed. However, this technique has a problem that an increase in dimensional tolerances between the optical scanning device and the photosensitive unit increases.

  In Japanese Patent Laid-Open No. 2007-140041 (Patent Document 2), the positioning of a plurality of photosensitive units in the arrangement direction and the positioning in the orthogonal direction perpendicular to the arrangement direction are matched with the positioning accuracy required in the design. Techniques have been proposed that are performed by positioning parts made of different materials. However, this technique has a problem that an increase in dimensional tolerances between the optical scanning device and the photosensitive unit increases.

  Further, in Japanese Patent Application Laid-Open No. 2006-150836 (Patent Document 3), the distortion of the main body chassis of the image forming apparatus is prevented from being transmitted to the optical housing, and the relative position and angle of the optical member and the like are not greatly changed to cause color misregistration. A technique for preventing the occurrence of this has been proposed. However, this technique has a problem that an increase in dimensional tolerances between the optical scanning device and the photosensitive unit increases.

JP 2007-164128 A JP 2007-140041 A JP 2007-164128 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus that always obtains a good image in any state and is excellent in unit exchangeability and maintainability.

  In order to solve the above problems, an image forming apparatus according to the present invention provides a photosensitive unit, a detachable optical scanning device that performs exposure scanning on the photosensitive unit, and the photosensitive unit. In an image forming apparatus provided with a developing unit for developing a latent image formed on a body unit in each case, one face plate is rotatably provided on the case, and a holding mechanism is provided on the photoconductor A holding position provided between the unit and the optical scanning device and the face plate, the face plate being positioned and held by the holding mechanism, and the holding being released. The image forming apparatus is characterized in that the photosensitive unit and the optical scanning device are rotatable between a detachable position where the photosensitive unit and the optical scanning device can be detached from the housing.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the hinge portion that rotatably holds the face plate is provided on the operation surface side of the image forming apparatus. It is provided in the slide part which slides forward from.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the holding mechanism includes the photosensitive unit, the optical scanning device, and the face plate. And a hole corresponding to the pin.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the photoconductor unit is disposed from the inside of the housing. It is detachable from the operation surface side of the housing.

  In addition, according to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the optical scanning device is disposed from the inside of the housing. It is characterized in that it is detached from the side surface of the housing.

  According to a sixth aspect of the present invention, in the optical scanning device according to the fifth aspect, the holding mechanism between the optical scanning device and the face plate is provided on the face plate. And a hole corresponding to the pin provided in the optical scanning device.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the face plate includes the photosensitive unit and the optical scanning device. The fan motor for cooling the space between is provided.

  The image forming apparatus according to the present invention is the image forming apparatus according to claim 7, wherein the fan motor is interlocked with a rotation operation of the face plate, and the face plate is held by the holding plate. It operates only when it is in a position.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the image forming apparatus according to any one of the first to eighth aspects is a tandem color image forming apparatus. And

  According to the image forming apparatus of the present invention, one face plate is rotatably provided on the housing, a holding mechanism is provided between the photoconductor unit, the optical scanning device, and the face plate, and The face plate has a holding position where the photosensitive unit and the optical scanning device are positioned and held by the holding mechanism, and the holding is released so that the photosensitive unit and the optical scanning device can be detached from the housing. Since the photosensitive unit and the optical scanning device are positioned and held by one face plate which is the same member, the dimension between the device and the unit is possible. The deviation from the ideal state due to the accumulation of tolerances can be minimized, and the mutual positional relationship between the device and the unit can always be maintained in a good state. As a result, the light beam characteristics exposed on the photosensitive unit can always be kept in a good state, and as a result, a good image can be obtained.

  According to a second aspect of the present invention, in the image forming apparatus according to the second aspect, the hinge portion that rotatably holds the face plate is provided on the slide portion that slides forward from the operation surface side of the image forming device. The size can be minimized, and the components constituting the apparatus can be reduced in size and cost. In addition, it is possible to improve the operability such that the force required for the opening / closing operation can be reduced.

  In the image forming apparatus according to claim 3, the holding mechanism includes a pin provided on the photosensitive unit, the optical scanning device, and the face plate, and a hole corresponding to the pin. Positioning and holding of the replacement unit can be performed only by opening and closing the face plate, and a fastening screw or the like can be eliminated, so that operability in replacement work can be improved.

  Here, the photosensitive unit is composed of a rotating body coated with a photosensitive agent. However, the photosensitive unit is periodically used due to the fatigue of the photosensitive agent over time or the damage to the surface of the photosensitive member that occurs unexpectedly. Or, it needs to be exchanged at will. Since the replacement cycle of such a photoreceptor unit is short with respect to the life of the apparatus, it is desirable to have a structure that can be easily replaced.

  Further, in the image forming apparatus according to claim 4, since the photoconductor unit is detached from the inside of the housing to the operation surface side of the housing, the removal of the photoconductor unit from the housing is performed on the front surface of the machine. Since it is operated from the (operating side), access by the operator can be facilitated and workability can be improved.

  In the image forming apparatus according to claim 5, the optical scanning device is mounted on the housing while maintaining the strength of the housing in order to be detached from the housing to the side surface of the housing. A reduction in the mounting accuracy between the devices and units can be prevented, and as a result, a good image can be obtained.

  In other words, the optical scanning device is not so frequently replaced as compared with the photosensitive unit, but it is often necessary to remove it from the housing, for example, by replacing a polygon motor mounted in the optical scanning device. Arise.

  In the invention described in claim 4 above, the attachment / detachment of the photosensitive unit from the housing is operated from the front of the machine. Similarly, in the case where it is configured to be attached / detached from the housing of the optical scanning device, If both the photosensitive unit and the optical scanning device are pulled out from the front frame (side plate) constituting the casing, the opening becomes large. At this time, since the area of the opening with respect to the side plate becomes large, the strength of the side plate itself is lowered, and as a result, the rigidity of the housing itself is lowered. As a result, each device and unit attached to the housing Will lead to a decrease in the mounting accuracy. The optical scanning device can be detached from the housing by operating from the side of the machine, not from the front of the machine, so that the opening of the housing can be minimized. At a certain level.

  In the image forming apparatus according to claim 6, the holding mechanism between the optical scanning device and the face plate includes a pin provided on the face plate and a hole provided in the optical scanning device corresponding to the pin. Therefore, there is no protrusion of the pin on the optical scanning device side, and it can easily fit between the side plates constituting the housing, so the pin is on the optical scanning device side and the hole is on the face plate side In the attachment / detachment of the optical scanning device from the side surface of the image forming apparatus, which occurs when the optical scanner is included, there is no interference between the housing and the pins, and therefore the replacement work of the attachment / detachment from the housing can be further improved.

  In the image forming apparatus according to claim 7, since the face plate includes a fan motor for cooling a space between the photoconductor unit and the optical scanning device, an installation space for the fan motor is reduced. There is no need to provide them individually in the forming apparatus, and the apparatus can be reduced in size and space.

  Here, the optical scanning device is often provided with a deflector (polygon motor) that rotates at high speed inside, and the heat generated from such a polygon motor is generated not only in the optical scanning device but also in the device. It will also affect the temperature rise.

  At such a high temperature, as the temperature of the surrounding atmosphere rises in the photoconductor, the temperature propagates to the adjacent developing unit, causing toner sticking, etc. May cause.

  As described above, it is very important to reduce the temperature rise around the photoconductor and the optical scanning device in the apparatus, and it is required to efficiently cool the inside of the apparatus. However, the above configuration enables efficient cooling. It becomes.

  In the image forming apparatus according to claim 8, when the face plate is not in the holding position because the fan motor operates only when the face plate is in the holding position in conjunction with the rotation of the face plate. That is, since the fan operation is stopped when the unit is replaced, it is possible to prevent an accident such as entanglement of a string-like object or a worker's hair due to the fan motor operation.

  The image forming apparatus according to claim 9 is applied to a tandem color image forming apparatus capable of simultaneously performing exposure scanning on a plurality of photoconductors and capable of forming images of different colors. Therefore, it is excellent in the quality stability, improves the maintainability of the apparatus and the operability in the unit replacement work, and can be an excellent full-color image forming apparatus.

2A is a model diagram of a side surface of an image forming apparatus A according to the present invention, and FIG. 2B is a model diagram of a front surface of the image forming apparatus A according to the present invention. FIG. 6 is a partial model view of the vicinity of a face plate in an example B of the image forming apparatus according to the present invention. 1A is a model perspective view of an image forming apparatus B according to the present invention. FIG. 3B is a model perspective view of the image forming apparatus B ′ according to the present invention. FIG. 3 is a vertical cross-sectional model diagram illustrating details of an image forming unit of the image forming apparatus B ′ according to the present invention. FIG. 3 is a model diagram near the face plate 6 of the image forming apparatus C according to the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1A shows a side model of the image forming apparatus A according to the present invention, and FIG. 1B shows a front (viewed from the front side and operation side) model.

  This image forming apparatus A includes a photosensitive unit 4, a removable optical scanning device 5 that performs exposure scanning on the photosensitive unit 4, and a developing unit for developing a latent image formed on the photosensitive unit 4. (Not shown) is an image forming apparatus provided with a side plate (front side, operation side) 1, a side plate 2 (rear side), and a housing formed (configured) from stays 3 a and 3 b connecting them. One face plate 6 is rotatably provided on the casing (side plate 1 on the operation side thereof), a holding mechanism is provided between the photosensitive unit 4 and the optical scanning device 5 and the face plate 6, and The face plate 6 is held by the holding mechanism (solid line) where the photosensitive unit 4 and the optical scanning device 5 are positioned and held by the holding mechanism, and the holding is released so that the photosensitive unit 4 and the optical scanning device 5 are in the housing. Detachable from Chakuichi and (dashed line), and can pivot between.

  That is, a single face plate 6 that can be rotated in the direction of a double arrow between a holding position (solid line) and an attachment / detachment position (broken line) is provided on the housing via a hinge 7. The photosensitive unit holding pins 4a and the face plate holding holes 6b corresponding to each other are provided as the holding mechanism, and the optical scanning device 5 and the face plate 6 are respectively provided with the corresponding optical scanning device holding holes 5a and the face plate holding. The pins 6a are provided as the holding mechanism. When the face plate 6 is in the holding position, the pins and the holes are fitted, and the photosensitive unit 4 and the optical scanning device 5 are positioned by these holding mechanisms. Held.

  Further, the photoconductor unit 4 and the optical scanning device 5 can be detached from the casing by releasing the above-mentioned holding by rotating the face plate 6 to the attachment / detachment position indicated by the broken line. In this example, the attachment / detachment position is shown at a position where the face plate 6 rotates about 90 °. However, this is only an example, and the angle is not limited to this. For example, the photosensitive unit 4 is attached / detached from the housing. In some cases, it may be sufficient to rotate to the extent possible.

  In this example A, since the size of the face plate 6 is increased so that the face plate holding pin 6a can be easily removed from the optical scanning device holding hole 5a, the operability is deteriorated and the size of the component is increased. There is a concern of causing cost and cost increase.

  When such a problem is concerned, it can be solved by the example B of the image forming apparatus according to the present invention in which a partial view of the vicinity of the face plate is schematically shown in FIG. That is, by providing the slide portion 8 that slides forward from the operation surface side of the image forming apparatus B and providing the hinge portion that rotatably holds the face plate 6 on the slide portion 8, first, the face plate 6 is moved by the slide portion 8. Is rotated after being slid forward from the operation surface side, or is rotated while being slid, so that the face plate holding pin 6a can be easily removed from the optical scanning device holding hole 5a and the size of the face plate 6 can be reduced. be able to.

  In the image forming apparatus of the present invention, the photoconductor unit is detached from the inside of the housing to the operation surface side of the housing, so that the photoconductor unit can be detached from the housing in front of the machine (operation side). Therefore, the operator can easily access and improve workability. Here, the image forming apparatus B is an image forming apparatus in which the photosensitive unit is detached from the inside of the casing to the operation surface side of the casing.

  FIG. 3A shows a model perspective view of the image forming apparatus B according to the present invention.

  In FIG. 3A, the slide portion 8 is slid forward from the operation surface side of the image forming apparatus B, and the face plate 6 is in the detaching position. In order to set the photoconductor unit 4 in the image forming apparatus B, the photoconductor unit 4 is inserted into the inside of the apparatus through the photoconductor unit insertion port 1a provided in the operation side plate 1 and the photoconductor on the rear side plate 2 is inserted. The photosensitive drum unit holding pin 4a is fitted into the unillustrated face plate holding hole 6b by setting the unit setting portion 2a, and then moving the face plate 6 to the holding position and turning, whereby the photosensitive body unit 4 is connected to the image forming apparatus B. Positioned and held internally.

  On the other hand, the optical scanning device 5 is detached from the inside of the housing to the side surface of the housing, and is attached to the inside of the housing from the side surface side of the housing. That is, from the left side surface of the image forming apparatus B, the optical scanning device 5 has the face plate holding pin 6a of the face plate 6 passed through the pin insertion 1b provided in the side plate 1 on the operation side after being installed in the device, and the optical scanning device holding hole 5a. When the face plate 6 is in the holding position, it is positioned and held by fitting the face plate holding pins 6a and the optical scanning device holding holes 5a.

  Here, in the case of the image forming apparatus B ′, which is an example applied to the tandem color image forming apparatus of the present invention, schematically shown in FIG. Higher efficiency can be obtained by the detaching and attaching operation from the side. In the case of this apparatus, the operation is the same as that of the image forming apparatus B except that the setting of the photosensitive unit 4 to the image forming apparatus B ′ is repeated four times.

  FIG. 4 is a vertical cross-sectional model diagram showing details of the image forming unit of the tandem type image forming apparatus B ′. The image forming apparatus B ′ includes a housing 42, a paper feeding device 3, a registration roller pair 44, a transfer unit 45, a fixing device 46, an optical scanning device 5, a first to a fourth process cartridge 8Y, 8C, 8M, 8BK and a paper discharge unit 49 are provided at least. In the following description, the four photoconductor units 4 of the image forming apparatus B ′ correspond to four color toners, and are separately described as 16Y, 16C, 16M, and 16BK.

  The apparatus main body 42 is formed in a box shape, for example, and is installed on a floor or the like. The apparatus main body 42 includes a paper feeding device 43, a registration roller pair 44, a transfer unit 45, a fixing device 46, an optical scanning device 5, and first to fourth process cartridges 8Y, 8C, 8M, and 8BK. House inside.

  The paper feeding device 43 is disposed below the device main body 42 and includes a paper feeding cassette 10 and a paper feeding roller 11. The paper feed cassette 10 accommodates the recording media P in an overlapping manner. The paper feed cassette 10 is arranged in the horizontal direction of the apparatus main body 42 so as to be freely inserted into and removed from the apparatus main body 2. The paper feeding roller 11 is pressed against the uppermost recording medium P in the paper feeding cassette 10, and the uppermost recording medium P is sent out in the direction of the arrow k by the rotation of the paper feeding roller 11.

  The registration roller pair 44 is provided in the conveyance path of the recording medium P conveyed from the paper feeding device 43 to the transfer unit 45, and sandwiches the recording medium P between each other. The registration roller pair 44 feeds the recording medium P to the transfer unit 45 at a predetermined timing.

  The transfer unit 45 is provided above the sheet feeding device 3. The transfer unit 45 includes a plurality of support rollers 12 a, 12 b, 12 c and an intermediate transfer belt 13. The plurality of support rollers 12a, 12b, and 12c are rotatably supported by the apparatus main body 42, and at least one of them is rotationally driven by a driving unit (not shown). The intermediate transfer belt 13 is formed in an endless annular shape, is wound around support rollers 12a, 12b, and 12c and is disposed above and in the vicinity of the process cartridges 8Y, 8C, 8M, and 8BK. The intermediate transfer belt 13 circulates (endlessly travels) in the direction of arrow m in FIG. 4 when the support rollers 12a, 12b, and 12c (any one) are driven to rotate.

  The transfer unit 45 further includes a primary transfer roller 14 and a secondary transfer roller 15. The primary transfer roller 14 and the secondary transfer roller 15 are arranged in the vicinity of the intermediate transfer belt 13, and a predetermined transfer voltage is applied by a power supply device (not shown).

  The secondary transfer roller 15 is disposed to face the support roller 12a. The recording medium P fed from the registration roller pair 44 is fed between the intermediate transfer belt 13 and the secondary transfer roller 15 supported by the support roller 12a, and on the intermediate transfer belt 13 as will be described later. The synthesized toner image that has been primarily transferred is secondarily transferred.

  The fixing device 46 includes a heating roller and a pressure roller that sandwich the recording medium P therebetween. The recording medium P on which the composite toner image has been secondarily transferred is further conveyed upward, passes through the fixing device 46, is pressed and heated between the heating roller and the pressure roller, and is secondarily transferred onto the recording medium P. The synthesized toner image is fixed on the recording medium P.

  The optical scanning device 5 is disposed between the paper feeding device 43 and the intermediate transfer belt 13. The optical scanning device 5 includes an outer periphery of the image carrier, that is, the photoreceptor units 16Y, 16C, 16M, and 16BK, which are uniformly charged by the charging members 23 described later of the first to fourth process cartridges 8Y, 8C, 8M, and 8BK. The surface is irradiated with laser light L to form an electrostatic latent image. The optical scanning device 7 performs image recording (forms an electrostatic latent image) on the outer peripheral surfaces of the photoreceptor units 16Y, 16C, 16M, and 16BK, for example, by scanning by rotation of a rotary polygon mirror.

  The first to fourth process cartridges 8Y, 8C, 8M, and 8BK, which are development units for developing the latent image formed on the photosensitive unit, are drum-shaped on which toner images of different colors are formed. Photoconductor units 16Y, 16C, 16M, and 16BK are provided as photoconductors. Different color toner images are formed on the photoreceptor units 16Y, 16C, 16M, and 16BK, and the toner images are superimposed on the intermediate transfer belt 13 and primarily transferred. The transfer residual toner adhering to the intermediate transfer belt 13 after the toner image is transferred is removed by the cleaning device 27. The intermediate transfer belt 13 constitutes an example of a transfer material onto which toner images formed on the photoreceptor units 16Y, 16C, 16M, and 16BK are transferred.

  In the image forming apparatus according to the present invention, it is preferable that the face plate is provided with a fan motor for cooling the space between the photosensitive unit and the optical scanning device. As such an example, a model diagram in the vicinity of the face plate 6 of the image forming apparatus C according to the present invention is shown in FIG. The image forming apparatus C is different only in that the face plate 6 is provided with a fan motor 9 for cooling the space between the photosensitive unit and the optical scanning device on the face plate. The fan motor 9 is operated only when the face plate 6 is in the holding position in conjunction with the rotation of the face plate 6 by a contact switch (not shown) in conjunction with the movement of the face plate 6. When the face plate is not in the holding position, that is, when the unit is replaced, the fan operation is stopped, so that it is possible to prevent an accident such as entanglement of the string-like object or the operator's hair due to the fan motor operation.

1 Side plate (front side, operation side)
2 Side plate (rear side)
3a, 3b Stay 4 Photosensitive unit 4a Photosensitive unit holding pin 5 Optical scanning device 5a Optical scanning device holding hole 6 Face plate 6a Face plate holding pin 6b Face plate holding hole 7 Hinge 8 Slide portion 9 Fan motor

Claims (9)

A housing includes a photosensitive unit, a removable optical scanning device that performs exposure scanning on the photosensitive unit, and a developing unit for developing a latent image formed on the photosensitive unit. In the image forming apparatus,
One face plate is rotatably provided on the housing,
A holding mechanism is provided between the photosensitive unit and the optical scanning device and the face plate; and
The face plate has a holding position where the photosensitive unit and the optical scanning device are positioned and held by the holding mechanism, and the holding unit is released so that the photosensitive unit and the optical scanning device can be detached from the housing. An image forming apparatus, wherein the image forming apparatus is rotatable between the attachment / detachment position.   The image forming apparatus according to claim 1, wherein a hinge portion that rotatably holds the face plate is provided on a slide portion that slides forward from the operation surface side of the image forming apparatus.   The said holding | maintenance mechanism is comprised from the hole provided in the said photoconductor unit, the said optical scanning device, and the said face plate, and the hole corresponding to this pin, The Claim 1 or Claim 2 characterized by the above-mentioned. Image forming apparatus.   4. The image forming apparatus according to claim 1, wherein the photosensitive unit is detached from the inside of the housing toward the operation surface side of the housing. 5.   5. The image forming apparatus according to claim 1, wherein the optical scanning device is attached to and detached from a side of the housing from the inside of the housing.   The holding mechanism between the optical scanning device and the face plate is configured by a pin provided in the face plate and a hole corresponding to the pin provided in the optical scanning device. The image forming apparatus according to claim 5.   The image according to any one of claims 1 to 6, wherein the face plate includes a fan motor for cooling a space between the photosensitive unit and the optical scanning device. Forming equipment.   The image forming apparatus according to claim 7, wherein the fan motor operates only when the face plate is in the holding position in conjunction with a rotation operation of the face plate.   9. The image forming apparatus according to claim 1, wherein the image forming apparatus is a tandem color image forming apparatus.

Images