JP2018013524A - Optical scanning device and method for manufacturing optical scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical scanning device that is robust and highly reliable without increasing the number of assembling processes, in which a plurality of scanning lenses can be simultaneously adhered and fixed without causing reduction in adhesion strength.SOLUTION: The optical scanning device includes a light source, a deflector for deflecting a laser beam from the light source into a main scanning direction, first and second scanning lenses located at positions opposing to each other interposing the deflector and allowing the laser beam from the deflector to pass through, a housing including the light source, the deflector and the first and second scanning lenses. The first and second scanning lenses each have flanges protruding from both ends in the main scanning direction, the flanges adhered and fixed to first and second fixing parts located at positions of the housing opposing to the flanges. The first fixing part corresponding to the first scanning lens is disposed on an incident side of the first scanning lens; while the second fixing part corresponding to the second scanning lens is disposed on an emission side of the second scanning lens.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical scanning device that deflects a light beam from a light source by a deflector and scans a scanned object such as a photosensitive member through a scanning lens, and a method for manufacturing the optical scanning device.

  Conventionally, a configuration as in Patent Document 1 is known as an optical scanning device mounted on a color image forming apparatus in which a plurality of photoconductors are arranged in a line to enable high-speed printing.

  In the above-described conventional example, the same number of scanning optical systems as the plurality of photosensitive members are included in one casing, and a plurality of lenses (second cylindrical lenses 60C and 60D in Patent Document 1) are mounted on a lens fixing portion that stands upright from the bottom surface of the casing. Bonded and fixed.

JP 2012-252125 A

  However, the conventional example has a problem that it is difficult to obtain the adhesive strength between the plurality of lenses and the casing.

  When a photo-curing adhesive is applied to a vertically standing wall-like adhesive surface as in Patent Document 1, the adhesive hangs down due to gravity with the time after application. Therefore, at the stage of irradiating the curing light for curing the adhesive, most of the adhesive accumulates under the lens, not between the lens and the lens fixing part of the casing. In this case, a sufficient adhesion area cannot be obtained.

  In order to prevent this, it is only necessary to apply the adhesive in a posture in which the casing is held 90 ° and the lens fixing portion is horizontal. However, in the case of an optical scanning device corresponding to a plurality of photoconductors, as disclosed in Patent Document 1, the optical arrangement is substantially symmetrical. For this reason, when the bonding operation is attempted in a posture in which the lens fixing portion is horizontal, the two lenses cannot be bonded at the same time, and it is necessary to change the posture of the casing for each lens. Further, in order to cure the adhesive, it is necessary to irradiate the curing light for several tens of seconds to several tens of seconds. If a plurality of lenses cannot be operated simultaneously, the assembly man-hour is greatly increased.

  It is an object of the present invention to perform a simultaneous and stable decrease in adhesive strength when bonding and fixing a plurality of scanning lenses, and to increase the number of assembling steps with a robust and reliable optical scanning device. Is to realize.

  In order to achieve the above object, the present invention provides a light source, a deflector for deflecting a laser beam from the light source in the main scanning direction, and a laser from the deflector disposed at positions facing each other with the deflector interposed therebetween. In the optical scanning device having first and second scanning lenses through which a light beam passes, a housing containing the light source, the deflector, and the first and second scanning lenses, the first and second scanning lenses are provided. In this scanning lens, the flange portions protruding at both ends in the main scanning direction are adhesively fixed to first and second fixing portions provided at positions facing the flange portions of the housing. The first fixing portion corresponding to the scanning lens is provided on the incident side of the first scanning lens, and the second fixing portion corresponding to the second scanning lens is the second scanning. Provided on the exit side of the lens And wherein the door.

  According to the present invention, when a plurality of scanning lenses are bonded and fixed, it is possible to carry out simultaneously without causing a decrease in adhesive strength, and without increasing the number of assembling steps, a robust and highly reliable optical scanning device. Can be realized.

1 is a diagram illustrating an optical scanning device according to a first embodiment. It is a figure showing the image forming apparatus in which an optical scanning device is mounted. FIG. 3 is a diagram illustrating a lens fixing unit of the optical scanning device according to the first embodiment. FIG. 3 is a diagram illustrating a lens bonding process of the optical scanning device according to the first embodiment. FIG. 6 is a diagram illustrating an optical scanning device according to a second embodiment.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. Therefore, unless specifically stated otherwise, the scope of the present invention is not intended to be limited thereto.

[Example 1]
An optical scanning apparatus according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a diagram illustrating an optical scanning device according to a first embodiment of the present invention. As shown in FIG. 1, the optical scanning device 200 includes light source units (light sources) 1 a and 1 b and a rotating polygon mirror (deflector) 2. The rotary polygon mirror 2 is rotated by the scanner motor 3 to deflect the laser light beams La and Lb from the light source units 1a and 1b in the main scanning direction. The optical scanning device 200 also includes a first scanning lens 4a through which the laser beam La from the light source unit 1a deflected by the rotary polygon mirror 2 and a laser beam Lb from the light source unit 1b deflected by the rotary polygon mirror 2. Has a second scanning lens 4b. The optical scanning device 200 further includes a folding mirror 5a that reflects the laser beam La that has passed through the first scanning lens 4a, and a folding mirror 5b that reflects the laser beam Lb that has passed through the second scanning lens 4b. . The first and second scanning lenses 4a and 4b are arranged at positions facing each other with the rotary polygon mirror 2 interposed therebetween. The light source units 1a and 1b, the rotary polygon mirror 2, the scanner motor 3, the first and second scanning lenses 4a and 4b, and the folding mirrors 5a and 5b are included in an optical housing 6. The light source units 1 a and 1 b are connected to a laser drive circuit board 7, and the laser drive circuit board 7 is fixed to the outer wall of the optical housing 6.

  Here, each of the first and second scanning lenses 4a and 4b has a substantially rectangular shape in which the cross-sectional shape in the sub-scanning direction orthogonal to the main scanning direction is long in the sub-scanning direction. The left and right brim portions 4c projecting in the direction are determined in the optical axis direction. Therefore, the first and second scanning lenses 4a and 4b are bonded and fixed to the first and second lens fixing portions 31a and 31b protruding substantially perpendicularly from the bottom surface 6a of the optical housing 6, respectively. The first and second lens fixing portions 31a and 31b are provided one by one at positions facing the flange portions 4c at both ends in the main scanning direction of the scanning lenses 4a and 4b. The first lens fixing portion 31a is disposed on the incident side of the first scanning lens 4a, and the second lens fixing portion 31b is disposed on the emission side of the second scanning lens 4b. Details of this will be described later.

  Next, the operation of the present optical scanning device will be described. The light source units 1a and 1b are independently controlled by the laser drive circuit board 7 and emit laser beams La and Lb that blink based on the image signal. These laser beams La and Lb are deflected in the main scanning direction (direction parallel to the paper surface) by the action of the rotary polygon mirror 2 that is rotationally driven by the scanner motor 3, and are incident on the scanning lenses 4a and 4b, respectively. The laser beams La and Lb are refracted by passing through the scanning lenses 4a and 4b, and are turned in a direction substantially perpendicular to the paper surface by the folding mirrors 5a and 5b, respectively, and then the surface of the photosensitive member (described in FIG. 2). Scanned and imaged above.

  FIG. 2 is a schematic sectional view showing an image forming apparatus equipped with the optical scanning device. The image forming process of the image forming apparatus will be described with reference to FIG. In FIG. 2, reference numeral 200 denotes the above-described optical scanning device. Here, the optical scanning device 200 exemplifies an apparatus capable of writing two colors with one unit. Therefore, in order to support four colors for printing a full-color image, a configuration in which two optical scanning devices are mounted on one image forming apparatus is illustrated.

  As described above, the two optical scanning devices 200 scan and image the laser beams on the photosensitive drums 201Y, 201M, 201C, and 201K. The photosensitive drums 201Y, 201M, 201C, and 201K are charged in advance by the chargers 202Y, 202M, 202C, and 202K, and an electrostatic latent image is formed on the surface of the photosensitive drums 201Y, 201M, 201C, and 201K. This electrostatic ray image is visualized as a toner image by the developing devices 203Y, 203M, 203C, and 203K. The toner images on the photosensitive drums 201Y, 201M, 201C, and 201K are sequentially superimposed and transferred onto the intermediate transfer belt 205 by the primary transfer rollers 204Y, 204M, 204C, and 204K that constitute the primary transfer unit facing the photosensitive drums ( Primary transfer).

  On the other hand, the recording paper 207 placed in the paper feed cassette 206 is fed out by the pickup roller 208 in synchronization with the above process. After that, the fed recording paper 207 is transferred to the four-color toner image on the intermediate transfer belt 205 at a time (secondary transfer) by a secondary transfer roller 209 that constitutes a secondary transfer unit facing the intermediate transfer belt 205. Is done. The recording paper 207 finally passes through the fixing device 210 to fix the toner image, and is discharged out of the apparatus.

  With reference to FIG. 3, the fixing part of the plurality of scanning lenses 4 a and 4 b to the optical housing 6, which is a feature of the present invention, will be described in detail. FIG. 3 is a main part perspective view showing the lens fixing part of the optical scanning device according to the first embodiment.

  As shown in FIG. 3, lens abutting surfaces 32a and 32b and lens adhesion surfaces 33a and 33b are respectively provided on the surfaces of the first and second lens fixing portions 31a and 31b facing the scanning lenses 4a and 4b. Is provided. The lens abutting surfaces 32a and 32b are portions that abut the flange portions 4c of the scanning lenses 4a and 4b, respectively. The lens adhesion surfaces 33a and 33b are portions for bonding and fixing the respective scanning lenses abutted against the abutting surfaces 32a and 32b.

  The feature of the present embodiment is that all of the lens bonding surfaces 33a and 33b corresponding to the two scanning lenses 4a and 4b face the same direction. Therefore, as shown in FIG. 3, the entire optical scanning device (optical housing 6) is placed upright so that the emission side of the first scanning lens 4a faces upward, so that the lens adhesion surfaces 33a and 33b are substantially omitted. Can be oriented horizontally and up. In this state, the bonding operation of the two scanning lenses 4a and 4b can be performed simultaneously.

  A manufacturing method for manufacturing the optical scanning device 200 will be described with reference to FIG. FIG. 4A to FIG. 4C are diagrams showing the bonding process of the plurality of scanning lenses 4a and 4b. In FIG. 4, only one scanning lens 4a side is illustrated, but the same applies to the other scanning lens 4b side. The plurality of scanning lenses 4a and 4b are bonded and fixed to the optical housing 6 through the following four steps.

  In the first step, the first and second lens fixing portions 31a and 31b provided on the optical housing 6 at positions facing the flange portions 4c of the first and second scanning lenses 4a and 4b face upward. It is a step of installing the optical housing 6 in a posture. That is, the first step is a step of raising the optical housing 6 in such a posture that the lens bonding surfaces 33a and 33b facing the flange portion 4c of each scanning lens face upward. This is performed using an installation table (not shown) or the like.

  The second step is a step of applying an adhesive to the upper surfaces (lens bonding surfaces 33a and 33b) of the first and second lens fixing portions 31a and 31b in the posture of the optical housing 6. That is, the second step is a step of applying the adhesive 42 to the lens bonding surfaces 33a and 33b. As shown in FIG. 4A, a predetermined amount is applied to the lens bonding surfaces 33a and 33b using a dispenser 41. This step can be performed simultaneously at a total of four locations, that is, all of the pair of lens bonding surfaces 33a and 33b provided at positions facing the flange portions of the plurality of scanning lenses 4a and 4b. The adhesive 42 is a photo-curing adhesive.

  In the third step, the flange portion 4c on the incident side of the first scanning lens 4a is installed on the adhesive surface 33a to which the adhesive 42 of the first lens fixing portion 31a is applied, and the second lens fixing portion 31a. This is a step of installing the flange 4c on the emission side of the second scanning lens 4b on the adhesive surface 33b to which the adhesive 42 is applied. That is, the third step is a step of installing the scanning lenses 4a and 4b on the lens fixing portions 31a and 31b to which the adhesive is applied. As shown in FIG. 4 (b), the scanning lenses 4a and 4b have a flange portion 4c on the abutting surfaces (lens reference surfaces) 32a and 32b (see FIG. 3) of the lens fixing portions 31a and 31b. While urging, the optical housing 6 is installed so as to abut against the lens sub-scanning reference surface 43 protruding from the bottom surface 6a. This is preferably performed using a biasing jig (not shown). The abutting surfaces (lens reference surfaces) 32a and 32b are provided on the sides of the lens bonding surfaces 33a and 33b of the lens fixing portions 31a and 31b, and are surfaces facing the lens bonding surfaces 33a and 33b of the flange portion 4c. Regulate the position. The lens sub-scanning reference surface 43 is provided so as to protrude from the bottom surface 6a of the optical housing 6, and regulates the position of the surface facing the bottom surface 6a of the collar portion 4c. The surface facing the bottom surface 6a of the flange portion 4c is a surface intersecting (orthogonal) with the surface facing the lens bonding surfaces 33a and 33b of the flange portion 4c.

  Here, even when the flange portion 4c is abutted against the abutting surfaces (lens reference surfaces) 32a and 32b, a slight gap remains between the flange portion 4c and the lens bonding surface 33a. The adhesive 42 applied in the second step is filled in the gap.

  The fourth step is a step of curing the adhesive. As shown in FIG. 4C, the curing light 45 is irradiated from the irradiator 44 to the adhesive 42 through the scanning lenses 4a and 4b for tens of seconds to several tens of seconds. Each scanning lens 4a, 4b is made of a transparent material that transmits the curing light 45, and the adhesive 42 can be irradiated with the curing light 45 through each scanning lens 4a, 4b. Furthermore, this process can also be performed simultaneously at a total of four locations, which are all of the pair of lens bonding surfaces 33a and 33b.

  Thereafter, the above-described urging jig is released, the optical scanning device (optical housing 6) is taken out from the installation table, and a series of steps is completed.

  As described above, according to the present embodiment, even when the plurality of scanning lenses 4a and 4b are bonded and fixed to the lens fixing portions provided perpendicular to the bottom surface 6a of the optical housing 6, all the fixing portions are bonded. Application of an adhesive and irradiation of curing light can be performed at a time with the surface horizontal. Therefore, the adhesive fixing between the scanning lenses 4a and 4b and the optical housing 6 can be performed at the same time without causing a decrease in the adhesive strength, and a robust and highly reliable optical scanning device can be provided.

  Further, according to this embodiment, it is not necessary to change the posture of the optical scanning device during the bonding operation. That is, it is not necessary to change the attitude of the optical housing 6 installed in the first step from the second step to the fourth step. Therefore, all the scanning lenses can be bonded and fixed at once (simultaneously), and the number of assembling steps can be greatly reduced.

[Example 2]
An optical scanning apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 5 is a diagram illustrating an optical scanning device according to a second embodiment of the present invention. In FIG. 5, 51 is a synchronization detection sensor, and 52 is a synchronization detection lens. Here, the synchronization detection sensor 51 is an optical sensor mounted on the laser drive circuit board 7, and is detection means for detecting the laser light beam deflected by the rotary polygon mirror 2. The synchronization detection lens 52 is a lens that condenses the laser beam deflected by the rotary polygon mirror 2 toward the synchronization detection sensor 51.

  Accordingly, the laser beam Lb from the light source unit 1b is deflected by the rotary polygon mirror 2 and then collected by the synchronization detection lens 52, and enters the synchronization detection sensor 51 prior to scanning on the photosensitive member. A synchronization detection signal is issued. The laser beams La and Lb that scan the photosensitive member blink in synchronization with the synchronization detection signal and write an image.

  In this embodiment, the synchronization detection sensor 51 and the synchronization detection lens 52 are provided on the second lens fixing portion 31b side where the lens fixing portion is provided on the emission side of the scanning lens. That is, the synchronization detection sensor 51 and the synchronization detection lens 52 are disposed on the second scanning lens side that is bonded and fixed to the second lens fixing portion 31b. More specifically, the synchronization detection sensor 51 and the synchronization detection lens 52 are arranged in a space between the rotary polygon mirror 2 of the optical housing 6 and the second lens fixing portion 31b to which the second scanning lens 4b is bonded and fixed. Has been.

  If the synchronization detection sensor 51 and the synchronization detection lens 52 are provided on the first lens fixing portion 31a side where the opposite lens fixing portion is provided on the incident side of the scanning lens, the lens fixing portion 31a and the laser are provided. In order to avoid interference with the light beam, the synchronization detection lens 52, and the like, it is necessary to dispose the scanning lenses 4a and 4b away from the rotary polygon mirror 2. This inevitably increases the distance between the folding mirrors 51a and 51b, resulting in an increase in the size of the optical scanning device. As a result, the distance between the photosensitive members 201 of the image forming apparatus also increases, leading to an increase in the size of the apparatus main body.

  However, according to the present embodiment, it is not necessary to enlarge the image forming apparatus main body in order to install the synchronization detection sensor 51 and the synchronization detection lens 52, and a compact image forming apparatus can be realized.

  In this embodiment, the configuration in which the synchronization detection sensor 51 and the synchronization detection lens 52 are arranged on the second scanning lens side that is bonded and fixed to the second lens fixing portion 31b is exemplified. It is not limited to. In the case of having only the synchronization detection sensor 51 without the synchronization detection lens 52, the synchronization detection sensor 51 may be disposed on the second scanning lens side that is bonded and fixed to the second lens fixing portion 31b.

[Other Examples]
In the above-described embodiment, the optical scanning device in which the optical system for two colors is mounted in one optical housing has been described as an example. However, the present invention is not limited to this. For example, the present invention may be applied to an optical scanning device in which an optical system for four colors is mounted in one optical housing.

  In the embodiment described above, four single-color image forming modules are used for the multi-color image forming module. However, the number used is not limited, and may be set as necessary.

  In the above-described embodiments, the printer is exemplified as the image forming apparatus, but the present invention is not limited to this. For example, the image forming apparatus may be another image forming apparatus such as a copying machine or a facsimile machine, or another image forming apparatus such as a multi-function machine combining these functions. In addition, an image forming apparatus is illustrated in which an intermediate transfer member is used, toner images of each color are sequentially transferred onto the intermediate transfer member, and the toner images carried on the intermediate transfer member are collectively transferred to a transfer material. However, it is not limited to this. For example, an image forming apparatus that uses a transfer material carrier and sequentially superimposes and transfers the toner images of the respective colors on the transfer material carried on the transfer material carrier. The same effect can be obtained by applying the present invention to an optical scanning device mounted on these image forming apparatuses.

1a, 1b ... Light source unit 2 ... Rotating polygon mirror 3 ... Scanner motor 4a, 4b ... Scanning lens 6 ... Optical housing 31a, 31b ... Lens fixing part 32a, 32b ... Lens contact surface 33a, 33b Lens adhesive surface 42 Adhesive 51 Synchronous detection sensor 52 Synchronous detection lens

Claims (7)

A first light source, a deflector that deflects the laser beam from the light source in the main scanning direction, and first and second scans that are arranged at positions facing each other across the deflector and through which the laser beam from the deflector passes. In an optical scanning device having a lens, a housing containing the light source, the deflector, and the first and second scanning lenses,
In the first and second scanning lenses, a flange portion protruding from both ends in the main scanning direction is adhesively fixed to first and second fixing portions provided at positions facing the flange portion of the housing. And
The first fixing portion corresponding to the first scanning lens is provided on the incident side of the first scanning lens, and the second fixing portion corresponding to the second scanning lens is the An optical scanning device provided on the emission side of the second scanning lens.   The optical scanning device includes detection means for detecting a laser beam deflected by the deflector, and the detection means is disposed on the second scanning lens side that is bonded and fixed to the second fixing portion. The optical scanning device according to claim 1, wherein:   The optical scanning device further includes a synchronization detection lens for condensing the laser beam deflected by the deflector toward the detection unit, and the synchronization detection lens is bonded and fixed to the second fixing portion. The optical scanning device according to claim 2, wherein the optical scanning device is disposed on the second scanning lens side.   The detection unit and the synchronization detection lens are arranged between the deflector of the housing and the second fixing portion to which the second scanning lens is bonded and fixed. 4. The optical scanning device according to 3.   A surface of each of the first and second fixing portions facing each scanning lens is provided with an abutting surface that abuts the scanning lens and an adhesive surface that adheres and fixes the scanning lens abutted against the abutting surface. The optical scanning device according to claim 1, wherein the optical scanning device is provided. A first light source, a deflector that deflects the laser beam from the light source in the main scanning direction, and first and second scans that are arranged at positions facing each other across the deflector and through which the laser beam from the deflector passes. A manufacturing method for manufacturing an optical scanning device including a lens, a housing containing the light source, the deflector, and the first and second scanning lenses,
The housing is installed in such a posture that the first and second fixing portions provided at positions facing the flange portions projecting at both ends of the first and second scanning lenses in the main scanning direction face upward. A first step of:
A second step of applying an adhesive to the upper surfaces of the first and second fixing portions in the attitude of the housing;
The flange portion on the incident side of the first scanning lens is installed on the surface of the first fixing portion on which the adhesive is applied, and the second fixing portion is applied on the surface on which the adhesive is applied. A third step of installing the flange on the exit side of the scanning lens;
Through the fourth step of curing the adhesive,
A method of manufacturing an optical scanning device, wherein the first and second scanning lenses are bonded and fixed to the first and second fixing portions of the housing.   The first and second scanning lenses are simultaneously bonded and fixed without changing the posture of the housing installed in the first step from the second step to the fourth step. Item 7. A method for manufacturing an optical scanning device according to Item 6.

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