JP2009169133A - Automatic cleaning mechanism and optical scanning device with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical scanning device capable of securing a high cleaning performance for a long period of time with a simple and compact configuration. <P>SOLUTION: In an automatic cleaning mechanism 5 which automatically cleans cover glass 4 of the optical scanning device constituted by storing a scanning optical system which emits light for writing an electrostatic latent image to a photoreceptor in a frame 2, and covering the emission port of the light emitted from the scanning optical system with the cover glass 4 by a cleaning member 9 which moves forward and backward in its longitudinal direction, both longitudinal ends of the cover glass 4 are exposed, a frame extension part 2a extending in the longitudinal direction from both longitudinal ends is arranged at a part lower than the upper surface of the cover glass 4, the cleaning member 9 is moved to the frame extension part 2a exceeding both longitudinal ends of the cover glass 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automatic cleaning mechanism that automatically cleans a cover glass that covers an emission port of light emitted from a scanning optical system, and an optical scanning device including the automatic cleaning mechanism.

  In an image forming apparatus such as a copying machine or a printer that employs an electrophotographic system, a photosensitive member uniformly charged by a charging unit is irradiated with light for writing an electrostatic latent image from an optical scanning device on the photosensitive member. An electrostatic latent image is formed on the surface, and each electrostatic latent image is developed with toner by a developing device to be visualized as a toner image.

  Here, the optical scanning device accommodates a scanning optical system that emits light for writing an electrostatic latent image to the photosensitive member, and an exit port for the light emitted from the scanning optical system and a cover glass covering the same. Is provided.

  In such an optical scanning device, if dirt or dust adheres to the surface of the cover glass, the optical characteristics deteriorate. Therefore, it is necessary to periodically clean the surface of the cover glass, and an automatic cleaning mechanism has been proposed. .

  For example, in Patent Document 1, the cover glass of the optical scanning device is moved in the sub-scanning direction (width direction) to clean the cover glass at one time, and receiving members are provided at both ends of the cover glass in the sub-scanning direction. An automatic cleaning mechanism has been proposed in which the toner removed from the toner is received by a receiving member, and the receiving member is provided with a scraping member for scraping off the toner adhering to the cleaning member.

Further, in Patent Document 2, the cover glass of the optical scanning device is moved in the main scanning direction to clean the cover glass, and the removed object storage trays are provided at both ends in the longitudinal direction of the cover glass, from the surface of the cover glass. There has been proposed an automatic cleaning mechanism in which the removed deposits are accommodated in a removed item storage tray portion to prevent scattering of the deposits and to prevent the deposits from reattaching to the cleaning member.
JP 2004-333799 A JP 2004-017607 A

  However, in the automatic cleaning mechanisms described in Patent Documents 1 and 2, since the cleaning member is constantly pressed and in contact with the upper surface of the cover glass at the time of image formation, the elastic body constituting the cleaning member is constantly stressed. As a result, the cleaning member changes over time and becomes permanently deformed, resulting in a problem that the cleaning performance deteriorates due to long-term use.

  Moreover, since the automatic cleaning mechanism described in Patent Documents 1 and 2 requires a scraping member and a removed object storage tray, there is a problem that the structure is complicated and the cost is increased.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is an automatic cleaning mechanism capable of ensuring high cleaning performance over a long period of time with a simple and compact configuration, and an optical scanning device including the same. Is to provide.

  In order to achieve the above object, a first aspect of the present invention includes a scanning optical system that emits light for writing an electrostatic latent image on a photosensitive member in a frame, and the light emitted from the scanning optical system. In the automatic cleaning mechanism that automatically cleans the cover glass of the optical scanning device that covers the exit opening of the cover glass with a cleaning member that reciprocates in the longitudinal direction, both ends of the cover glass in the longitudinal direction are exposed. A frame extension extending in the longitudinal direction from both longitudinal ends of the cover glass is disposed below the upper surface of the cover glass, and the cleaning member is moved to the frame extension beyond the longitudinal end of the cover glass. It is characterized by that.

  According to a second aspect of the present invention, in the first aspect of the present invention, the depth of the frame extension is set to a value at which the tip of the cleaning member does not contact.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the cleaning member is held substantially perpendicular to the upper surface of the cover glass.

  An optical scanning device according to a fourth aspect includes the automatic cleaning mechanism according to any one of the first to third aspects.

  According to invention of Claim 1, while exposing the longitudinal direction both ends of a cover glass, the flame | frame extension part extended in a longitudinal direction from the longitudinal direction both ends is arrange | positioned below the upper surface of a cover glass, Cleaning member Since the cover glass is moved to the frame extension part beyond the longitudinal end of the cover glass, the toner and dust on the cover glass can be reliably scraped off and removed by the cleaning member. Thus, no toner or dust remains on the cover glass, and all of the toner and dust on the cover glass can be scraped off onto the frame extension.

  According to the second aspect of the present invention, the cleaning member that has moved to the frame extension is in a free state without coming into contact with the frame extension, and the stress acting on the cleaning member is released, so that the cleaning member is permanently deformed. It is prevented and high cleaning performance is ensured over a long period of time.

  According to the third aspect of the present invention, the toner and dust adhering to the cleaning member held substantially vertically are shaken off by the impact when the cleaning member crosses the step between the cover glass and the frame extension. Toner and dust adhering to the cleaning member can be removed without providing a separate means, thereby ensuring high cleaning performance for the cleaning member.

  According to the fourth aspect of the present invention, high cleaning performance is ensured over a long period of time in the automatic cleaning mechanism, so that high-precision optical scanning is possible and high-quality images can be stably obtained. In particular, in a color image forming apparatus, color misregistration of an image does not occur and a high quality color image can be obtained.

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

  1 is a perspective view of an optical scanning device according to the present invention, FIG. 2 is an enlarged perspective view of a main part of the optical scanning device, FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 5 is an enlarged detailed view of a portion C in FIG.

  The optical scanning device 1 according to the present embodiment is provided in an image forming apparatus such as a copying machine or a printer that employs an electrophotographic system, particularly a color image forming apparatus in which a plurality of photosensitive drums (not shown) are arranged in parallel. A laser scanner unit (LSU) having four photosensitive drums corresponding to magenta (M), cyan (C), yellow (Y) and black (K) colors in a rectangular box-shaped frame 2 In contrast, four scanning optical systems that emit laser light for writing an electrostatic latent image are accommodated in tandem in the longitudinal direction (left-right direction in FIG. 1).

  The cover 3 covering the upper surface of the frame 2 is formed with four rectangular elongated exits (not shown) through which the laser beams emitted from the four scanning optical systems pass, respectively. The mouth is covered with a transparent elongated cover glass 4 that transmits light. Here, each exit port and the cover glass 4 covering this form a rectangular shape that is long in the main scanning direction of the laser light with respect to each photosensitive drum (left and right direction in FIG. 3), and the surface of each cover glass 4 is automatically cleaned. It is automatically cleaned by the mechanism 5.

  Thus, in the present embodiment, as shown in FIGS. 3 to 5, both ends in the longitudinal direction of the cover glass 4 are exposed and the frame 2 is extended in the longitudinal direction from both ends in the longitudinal direction of the cover glass 4. The portion 2 a is arranged below the upper surface of the cover galam 4.

  Here, the configuration of the automatic cleaning mechanism 5 will be described.

  As shown in FIG. 1, the laser scanner unit 1 according to the present embodiment is provided with four sets of automatic cleaning mechanisms 5, and the four cover glasses 4 are simultaneously cleaned by the respective automatic cleaning mechanisms 5.

  Each automatic cleaning mechanism 5 is driven by a drive motor (not shown) provided in the laser scanner unit 1 itself, and the drive motor is disposed at the center in the longitudinal direction of the frame 2 of the laser scanner unit 1. Specifically, at the center of the frame 2 of the laser scanner unit 1, there is a single polygon mirror (rotating polygonal mirror) common to a plurality of scanning optical systems and a polygon motor (not shown) that rotates the polygon mirror. The drive motor is arrange | positioned beside it. A drive motor that can rotate forward and backward is used.

  By the way, as shown in FIG. 1, each automatic cleaning mechanism 5 has a screw shaft 6 that is long disposed in the main scanning direction of laser light (left-right direction in FIG. 3) on a cover 3 that is attached to the upper surface of the frame 2. As shown in FIG. 1, the screw shaft 6 is rotatably supported by bearings 7 at both ends in the axial direction.

  Each automatic cleaning mechanism 5 is provided with a holding member 8 screwed into the screw shaft 6 and a cleaning member 9 (see FIG. 4) attached to the holding member 8. Each cleaning member 9 is made of a blade member having elasticity, and can be cleaned by rubbing the surface of each cover glass 4 in a plan view (that is, the surface of each cover glass 4 is rubbed). 4 and is held substantially perpendicular to the upper surface of the cover glass 4 as shown in FIG.

  In this embodiment, the frame extension 2a extending in the longitudinal direction from both ends in the longitudinal direction of the cover glass 4 is arranged below the upper surface of the cover glass 4 in the frame 2 as described above. Thus, the depth of the frame extension 2a is set to a value at which the tip of the cleaning member 9 does not contact.

  Thus, when the image forming operation is repeated in the color image forming apparatus, there arises a problem that the optical characteristics are gradually deteriorated because dirt and dust adhere to the surface of the cover glass 4 of the laser scanner unit 1. For this reason, in the laser scanner unit 1 according to the present embodiment, the surface of each cover glass 4 is automatically cleaned by the automatic cleaning device 5.

  That is, when a drive motor provided in the laser scanner unit 1 itself is driven, the rotation is transmitted to each screw shaft 6 through a gear train (not shown), and the four screw shafts 6 are simultaneously rotated. .

  When transmitted to the four screw shafts 6 as described above, the holding member 8 threadedly inserted into each screw shaft 6 moves along the main scanning direction (left-right direction in FIG. 3) of the laser light. When each holding member 8 moves in this way, the cleaning member 9 attached to the holding member 8 also moves in the same direction while rubbing the surface of each cover glass 4, and dirt adhered to the surface of each cover glass 4. The dust is removed by the cleaning member 9, and the surface of each cover glass 4 is cleaned.

  Then, if the drive motor is rotated forward and backward, each screw shaft 6 is also rotated forward and backward, so that each holding member 8 and the cleaning member 9 attached thereto reciprocate on each cover glass 4 to reciprocate. 9, each cover glass 4 is cleaned. In this embodiment, as shown in FIG. 4, the cleaning member 9 is moved beyond the longitudinal end of the cover glass 4 to the extension 2a of the frame 2. I have to.

  Thus, according to the present embodiment, both ends in the longitudinal direction of the cover glass 4 are exposed, and the frame extension 2a extending in the longitudinal direction from the both ends in the longitudinal direction is disposed below the upper surface of the cover galam 4. Since the cleaning member 9 is moved to the frame extension 2a beyond the end portion of the cover glass 4 in the longitudinal direction, the toner, dust, etc. on the cover glass 4 are surely scraped and removed by the cleaning member 9. Thus, no toner or dust remains on both ends of the cover glass 4 in the longitudinal direction, and all of the toner and dust on the cover glass 4 can be scraped off onto the frame extension 2a.

  In the present embodiment, the cleaning member 9 that has moved to the frame extension 2a is in a free state without coming into contact with the frame extension 2a as shown in FIG. 4, and the stress acting on the cleaning member 9 is released. Permanent deformation of the cleaning member 9 is prevented, and high cleaning performance is ensured over a long period of time.

  Further, in the present embodiment, the toner or dust attached to the cleaning member 9 held substantially vertically by the holding member 8 is an impact when the cleaning member 9 exceeds the step between the cover glass 4 and the frame extension 2a. Therefore, the toner and dust adhering to the cleaning member 9 can be surely removed without providing any scraping means, thereby ensuring high cleaning performance for the cleaning member 9.

  As described above, the automatic cleaning mechanism 5 provided in the laser scanner unit 1 ensures high cleaning performance over a long period of time, so that high-precision optical scanning is possible and high-quality images are stably obtained. Can do. In particular, in the color image forming apparatus according to the present embodiment, a high-quality color image can be obtained without causing color misregistration of the image.

  Although the present invention has been described with respect to an embodiment in which the present invention is applied to an optical scanning device provided in a color image forming apparatus and an automatic cleaning mechanism provided therein, the present invention is an optical scanning device provided in a monochrome image forming apparatus. Of course, the present invention can also be applied to the automatic cleaning mechanism provided in this.

1 is a perspective view of an optical scanning device according to the present invention. It is an expansion perspective view of the principal part of the optical scanning device concerning the present invention. It is the sectional view on the AA line of FIG. It is the B section enlarged detail drawing of FIG. FIG. 5 is an enlarged detail view of a C part in FIG. 4.

Explanation of symbols

1 Laser scanner unit (optical scanning device)
2 Frame 2a Frame Extension 3 Scanning Optical System 4 Cover Glass 5 Automatic Cleaning Device 6 Screw Shaft 7 Bearing 8 Holding Member 9 Cleaning Member

Claims (4)

A scanning optical system that emits light for writing an electrostatic latent image to a photosensitive member is housed in a frame, and an exit of light emitted from the scanning optical system is covered with a cover glass. In an automatic cleaning mechanism that automatically cleans a cover glass by a cleaning member that reciprocates in its longitudinal direction,
Both ends of the cover glass in the longitudinal direction are exposed, a frame extension extending in the longitudinal direction from the both ends in the longitudinal direction is disposed below the upper surface of the cover glass, and the cleaning member is disposed in the longitudinal direction of the cover glass. An automatic cleaning mechanism characterized by being moved to the frame extension part beyond the part.   The automatic cleaning mechanism according to claim 1, wherein the depth of the frame extension is set to a value at which the tip of the cleaning member does not contact.   The automatic cleaning mechanism according to claim 1, wherein the cleaning member is held substantially perpendicular to the upper surface of the cover glass. An optical scanning device comprising the automatic cleaning mechanism according to claim 1.

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