JP2007050540A - Light source device, optical scanner, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fix a semiconductor laser element so as not to be moved, after inserting the semiconductor laser element into a light source holding member. <P>SOLUTION: A fitting hole 22A for allowing the light-emitting part 21A of the semiconductor laser element 21 is formed in the light source holding member 22 which holds the semiconductor laser element 21, and a claw 30 for preventing falling-off of the semiconductor laser element 21 is provided protrusively in the inner wall of the fitting hole 22A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light source device including a semiconductor laser element, an optical scanning device, and an image forming apparatus.

  Some image forming apparatuses such as digital copying machines and laser printers form an image on an image carrier using light emitted from a light source. The light source of such an apparatus is irradiated by a semiconductor laser element, for example. FIG. 8 shows the apparatus. In this light source device, the light emitting portion 21A of the semiconductor laser element 21 is press-fitted into the holding hole 22A of the light source holding member 22, and the flange portion 21B is in contact with the stepped portion. As a result, the semiconductor element 21 is fixed to the light source holding member 22. A light beam emitted from the semiconductor laser element 21 is coupled by a coupling lens 23 fixed to a protruding portion of the light source holding member 22.

  In such a light source device, the distance from the light emitting point of the semiconductor laser element 21 to the coupling lens 24 and the positional relationship between the light emitting point of the semiconductor laser element 21 and the optical axis of the coupling lens 24 are required to be precise. Further, it is required that the position of the semiconductor laser element 21 does not change after the semiconductor laser element 21 is press-fitted into the light source holding member 22.

  Therefore, conventionally, the pressure input when mounting the semiconductor laser element 21 is increased, and the semiconductor laser element 21 is fixed to the light source holding member 22. As a method for fixing the semiconductor laser element 21 to the light source holding member 22 other than press-fitting, there is a leaf spring and screwing method.

  In addition, JP-A-6-325373 provides a semiconductor laser fixing mechanism. The invention of Japanese Patent Laid-Open No. 6-325373 reduces the cost of the apparatus by reducing the variation in the amount of pressure input to the holding member, reducing the number of parts, and increasing the space efficiency. It is an object of the present invention to provide a semiconductor laser fixing mechanism capable of increasing the positioning accuracy in the rotation direction. Japanese Patent Laid-Open No. 6-325373 discloses a semiconductor laser, a holding member for holding the semiconductor laser, and a semiconductor laser fixing mechanism in which a flange portion of the semiconductor laser is formed with a press-fitting hole in the holding member. At least one concave relief portion is formed as a non-contact portion with the flange portion.

Further, Japanese Patent Application Laid-Open No. 2003-98464 fixes the light source to the light source holding member without damaging it, and makes it difficult to cause positional deviation even when the environment such as temperature fluctuates or an impact force is applied. . In the optical scanning apparatus and image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-98464, a taper member insertion hole is formed in the vicinity of a stepped hole for holding a semiconductor laser element of a base, and the taper member is press-fitted into the taper member insertion port. When the semiconductor laser element is inserted into the hole and the taper member is inserted into the taper member insertion port, the peripheral wall portion of the taper member insertion hole is expanded. Thereby, the outer periphery of the collar part of the semiconductor laser element is pressed and fixed to the wall surface of the stepped hole.
JP-A-6-325373 JP 2003-98464 A

  However, in the above-described conventional press-fitting method, since the pressure input of the semiconductor laser element is large, the light source holding member is deformed, and the positional relationship between the light emitting point of the semiconductor laser element and the coupling lens is not constant.

  Further, when the semiconductor laser element is press-fitted into the light source holding member, the pressure input and the press-fit state depend on the relationship between the diameter and shape of the flange portion of the semiconductor laser element and the diameter and shape of the press-fitting hole of the light source holding member. Therefore, when the diameter of the flange portion of the semiconductor laser element is large and the diameter of the press-fitting hole of the light source holding member is small, the semiconductor laser element is not press-fitted to the back of the step portion of the light source holding member and stops halfway. The distance between the light emitting point of the semiconductor laser element and the coupling lens is not constant.

  Further, in Japanese Patent Laid-Open No. 6-325373, when the semiconductor laser element is inserted into the holding member, the press-fitting hole is expanded so as to be expanded, so that stress remains in the holding member having the press-fitting hole and is deformed. There is also a possibility that the semiconductor laser is pressed in an inclined state due to the frictional force at the time of press-fitting, and fixed while the light emission direction is out of order.

  Further, in Japanese Patent Application Laid-Open No. 2003-98464, there is no problem in the light emission direction of the semiconductor laser element, but there is a production disadvantage in that the number of parts and the number of work steps are large.

  In addition, in the plate spring and screwing method in the above prior art, a plurality of components such as a light source holding member, a plate spring, and a screw are required to hold the semiconductor laser element, and the component cost is increased. Fixing work takes time.

  The present invention has been made in view of the above problems, and when inserting a semiconductor laser element into a light source holding member, an unnecessary force is not applied, and after inserting the semiconductor laser element into the light source holding member, the semiconductor laser The purpose is to fix the element so that it does not move, and at the same time, it is intended to be able to do without increasing the cost of parts and increasing the working time.

  In order to solve the above-mentioned problem, a light source device according to claim 1 of the present application forms a mounting hole for inserting a light emitting portion of the semiconductor laser element in a holding member that holds the semiconductor laser element, and an inner wall of the mounting hole And a mechanism for preventing the semiconductor laser element from coming off.

  The light source device according to claim 2 of the present application is characterized in that, in the light source device according to claim 1, the removal prevention mechanism is formed integrally with the holding member.

  A light source device according to a third aspect of the present invention is characterized in that in the light source device according to any one of the first and second aspects, the removal preventing mechanism is provided on the entire inner wall of the mounting hole.

  A light source device according to a fourth aspect of the present invention is the light source device according to any one of the first to third aspects, wherein a plurality of the prevention mechanisms are provided on the inner wall of the mounting hole.

  The optical scanning device of this application has the light source device as described in any one of Claims 1-4.

  An image forming apparatus according to the present application is characterized in that the optical scanning device according to claim 5 is used as an image writing unit to an image carrier.

  According to the light source device of claims 1 to 3, the optical scanning device of claim 5, and the image forming device of claim 6, the semiconductor is inserted into the mounting hole for inserting the light emitting portion of the semiconductor laser element in the optical holding member. Providing a laser element removal prevention mechanism can prevent movement of the semiconductor laser element after insertion. Also, since the semiconductor laser element is held in the mounting hole by the prevention mechanism, the pressure input when fixing the semiconductor laser element can be reduced, and the light source holding member is deformed due to the insertion of the semiconductor laser element. Can be prevented. For this reason, the positional relationship between the light emitting point of the semiconductor laser element and the coupling lens becomes constant, the optical axis does not change, and the quality of the light source device, optical scanning device, and image forming apparatus can be stabilized.

  Further, since the pressure input may be small, it is not necessary to make the insertion hole unnecessarily small in order to increase the frictional force to be fixed to the light source holding member, so that the semiconductor laser element stops in the middle of the mounting hole of the light source holding member. This eliminates the possibility of being located at a predetermined position. For this reason, the distance between the light emitting point of the semiconductor laser element and the coupling lens can always be constant. This eliminates the need to check the fixing state of the semiconductor laser element after the semiconductor laser element is inserted into the light source holding member, leading to a reduction in work time.

  In addition, since the laser diode element removal prevention mechanism is integrally formed with the light source holding member, the number of parts and work processes can be reduced compared to leaf springs and screwing methods, and the cost of parts can be reduced and the work time can be reduced. Can be shortened.

  Hereinafter, a light source device according to the best mode for carrying out the present invention will be described with reference to the drawings.

  1 is a longitudinal sectional view showing an embodiment of a light source device according to the present invention, FIG. 2 is a plan view showing an example of an optical scanning device provided with the light source device, and FIG. 3 is equipped with the optical scanning device of FIG. It is a schematic block diagram which shows an example of the laser printer which performed.

  A light source device 1 shown in FIG. 1 is provided in an optical scanning device of a laser printer which is an image forming apparatus. Examples of the image forming apparatus include a copying machine and a facsimile in addition to a laser printer. The light source device 1 includes a semiconductor laser element 21 serving as a laser light source, a light source holding member 22 that holds the semiconductor laser element 21, and a coupling lens 23 that couples a light beam emitted from the semiconductor laser element 21. .

  FIG. 2 shows an optical scanning device 2 provided with a light source device 1. The optical scanning device 2 is mounted on the laser printer shown in FIG. In this laser printer, a photoconductive photosensitive drum 3 formed in a cylindrical shape, which is an image carrier, is disposed in the approximate center of the printer main body. Around the photosensitive drum 3, a charging roller 4 that functions as a charging unit, a developing device 5, a transfer roller 6, and a cleaning device 7 are provided. A corona charger may be used as the charging means.

  An optical scanning device 2 that performs optical scanning with a laser beam is provided above the charging roller 4. The optical scanning device 2 performs light writing exposure on a portion of the surface of the photosensitive drum 3 positioned between the charging roller 4 and the developing device 5. A fixing device 9 is provided on the downstream side of the photosensitive drum 3 in the transfer sheet conveyance direction, and a sheet feeding cassette (not shown) is detachably provided at the lower portion of the apparatus main body. A registration roller pair 8 is provided in the conveyance path between the paper feed cassette and the photosensitive drum 3. In the paper feed cassette, transfer paper 10 is stored as a recording medium. The transfer paper 10 is fed from a paper feed cassette and forms an image, then passes through the fixing device 9, is transported in a transport path, and is discharged to a predetermined position.

  When the laser printer starts an image forming operation, the photosensitive drum 3 starts to rotate in the direction of arrow A at a constant speed. Then, when the surface is uniformly charged by the charging roller 4 and the charged surface is exposed by the laser beam of the optical scanning device 2, optical writing is performed and an electrostatic latent image is formed. The formed electrostatic latent image is a so-called “negative latent image”, and the image is exposed. The electrostatic latent image on the photosensitive drum 3 is moved to a certain position of the developing device 5 by the rotation of the photosensitive drum 3, and the toner is attached by the developing device 5 to form a reversely developed toner image.

  On the other hand, the uppermost sheet of transfer paper 10 is fed from the paper feed cassette, and the fed transfer paper 10 is abutted against the resist roller pair 8 in a stopped state and temporarily stopped. Then, the registration roller pair 8 rotates in accordance with the timing at which the toner image on the photoconductive drum 3 moves to a transfer position where the transfer roller 6 is located, and the transfer paper 10 is brought into contact with the transfer roller 6 and the photoconductive drum 3. To send.

  The transfer paper 10 fed between the transfer roller 6 and the photosensitive drum 3 is heated and pressed in a state where it is overlapped with the toner image to transfer the toner image. The transfer paper 10 on which the toner image has been transferred is sent to the fixing device 9 where the toner image is fixed, and then conveyed through a conveying path and discharged. After the toner image is transferred to the transfer paper 10, residual toner, paper dust, and the like remaining on the photosensitive drum 3 are removed by the brush roller 7A and the blade 7B of the cleaning device 7.

  The optical scanning device 2 functions as an image writing unit that performs writing on the photosensitive drum 3 by optical scanning to form an electrostatic latent image. The optical scanning device 2 has a configuration as shown in FIG. 2 as an example. The optical scanning device 2 has a light source device 1. The optical scanning device 2 has an optical housing 14.

  In the optical housing 14, a cylindrical lens 11 that converges the laser beam emitted from the light source device 1, and a polygon mirror 12 that scans the laser beam by reflecting the laser beam on a mirror surface while rotating about the rotation axis, and An fθ lens 13 that converges the laser beam reflected by the polygon mirror 12 at a predetermined distance in accordance with an angle in the scanning direction, a folding mirror 15 that reflects the laser beam that has passed through the fθ lens 13 and changes its direction, and the like. It is stored.

  The upper part of the optical housing 14 is covered with an upper lid fixed by screwing or the like. In this optical scanning device 2, a laser beam emitted from the light source device 1 is formed into a long line image in the main scanning direction in the vicinity of the polygon mirror 12 by the cylindrical lens 11. The polygon mirror 12 reflects and polarizes each laser beam incident through the cylindrical lens 11 and scans the laser beam in the main scanning direction at a substantially equal angular velocity. The fθ lens 13 receives each laser beam which is reflected and polarized by the polygon mirror 12 and is scanned, reflects the light by the folding mirror 15, and focuses the reflected light beam on the surface to be scanned on the photosensitive drum 3. .

  As shown in FIG. 1, the light source device 1 includes a semiconductor laser element 21, a light source holding member 22 that holds the semiconductor laser element 21, and a coupling lens 23 that couples a light beam emitted from the semiconductor laser element 21. It has.

  The light source holding member 22 that holds the semiconductor laser element 21 of the light source device 1 is formed with a mounting hole 22A into which the light emitting portion 21A of the semiconductor laser element 21 is inserted, and the semiconductor laser element 21 is prevented from coming off on the inner wall of the mounting hole 22A. The nail | claw 30 is protrudingly provided. The mounting hole 22 </ b> A may be supported by pressure input enough to fit the light emitting portion 21 </ b> A of the semiconductor laser element 21. The mounting hole 22A is a hole for inserting the cylindrical light emitting part 21A of the semiconductor laser element 21, and the rear part of the mounting hole 22A is an insertion hole 22B having a large diameter for inserting the flange part 21B of the semiconductor laser element 21. .

  That is, although the diameters of the inner walls of the mounting hole 22A and the insertion hole 22B are different, the insertion hole 22B is a part of the mounting hole 22A. A boundary portion between the mounting hole 22A and the insertion hole 22B is a stepped portion 22C, and the stepped portion 22C supports the flange portion 21B of the semiconductor laser element 21.

  As shown in FIG. 4, a protrusion 30 is formed on the inner wall surface of the insertion hole 22B as a mechanism for preventing the semiconductor laser element 21 from coming off. The protrusions 30 for preventing the removal are formed integrally with the light source holding member 22, and three are formed at intervals on the inner wall of the insertion hole 22B. The number of the protrusions 30 may be one on the inner wall of the insertion hole 22B, two or more, or may be formed on the entire outer periphery of the press-fitting hole.

  The semiconductor laser element 21 is press-fitted to the stepped portion 22C of the mounting hole 22A, and the protrusion 30 for preventing removal is hooked on the bottom surface of the semiconductor laser element 21 as shown in FIGS. Hold.

  As shown in FIGS. 5A and 5B, examples of the drop prevention mechanism include a triangular drop prevention protrusion 31 and a semicircular drop prevention protrusion 32. These protrusions protrude from the inner wall surface of the hole of the light source holding member 22 and may have any shape that can be hooked on the flange 21B or the bottom surface of the semiconductor laser element 21.

  FIG. 6 shows a first modification of the drop prevention mechanism. The protrusions 30 of the above-described removal prevention mechanism are formed by claws. However, in the first modified example of FIG. 6, the recesses 34 are formed on the inner wall surface side of the claws 33, while the claws 33 are projected into the insertion holes 22B. The light source holding member 22 is resin-molded so as to form the claw 33 so that the claw 33 can be bent into the recess 34 and the flange portion 21B can be brought into contact with the stepped portion 22C.

  With such a claw 33, when the light emitting part 21A of the semiconductor laser element 21 is inserted into the mounting hole 22A and the collar part 21B gets over the claw 33, the collar part is interposed between the claw 33 and the step part 22C. 21B is sandwiched, the semiconductor laser element 21 is fixed, no deformation stress remains in the light source holding member 22, and when the claw 33 is pushed into the recess 34 for repair or the like, the collar portion 21B can be removed from the claw 33 and taken out. It becomes.

  FIG. 7 shows a second modification of the drop prevention mechanism. As shown in FIG. 7, a locking recess 22D is formed in the insertion hole 22B on the stepped portion 22C side of the mounting hole 22A, and a latching claw 41 is formed on the outer periphery of the fixed cylinder 40 for fixing the flange portion 21B. May be. The latching claw 41 can enter the locking recess 22D.

  In the case of the disconnection prevention mechanism of FIG. 7, after the semiconductor laser element 21 is inserted into the mounting hole 22A, when the flange portion 21B is pressed against the stepped portion 22C with the fixed cylinder 40, the latching claw 41 is placed in the locking recess 22D. The semiconductor laser element 21 is fixed to the mounting hole 22A by entering and bending, and the tip of the latching claw 41 is caught in the locking recess 22D. In addition, when the portion having the mounting hole 22A is formed in advance as the cylindrical body 42, and the semiconductor laser element 21 is fixed to the cylindrical body 42, the hole 43 of the light source holding member 22 is fixed with screws or claws. Although there are a plurality of molded products, it is not necessary to greatly change the mold of the light source holding member 22, and attachment or replacement is possible only by molding the cylindrical body 42 or the fixed cylindrical body 40.

It is a longitudinal cross-sectional view which shows one example of embodiment of the light source device concerning embodiment of this invention. It is a top view which shows an example of the optical scanning device provided with the light source device of FIG. It is a schematic block diagram which shows an example of the laser printer which is an image forming apparatus carrying the optical scanning device of FIG. It is a front view which shows the light source vicinity of the light source device of FIG. It is a figure which shows the example of a prevention mechanism. It is a figure which shows the 1st modification of a removal prevention mechanism. It is a figure which shows the 2nd modification of a removal prevention mechanism. It is a longitudinal cross-sectional view which shows an example of the conventional light source device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source device 2 Optical scanning device 3 Photosensitive drum 4 Charging roller 5 Developing device 6 Transfer roller 7 Cleaning device 8 Registration roller pair 9 Fixing device 10 Transfer paper 11 Cylindrical lens 12 Polygon mirror 13 Scanning lens 14 Optical housing 15 Folding mirror 21 Semiconductor Laser element 22 Light source holding member 23 Coupling lens 30 Claw for preventing removal (prevention mechanism)
31 Claw for preventing semi-circular omission

Claims (6)

  A light source device characterized in that a mounting hole for inserting a light emitting portion of the semiconductor laser element is formed in a holding member for holding the semiconductor laser element, and a mechanism for preventing the semiconductor laser element from coming off is provided on an inner wall of the mounting hole. .   The light source device according to claim 1, wherein the removal prevention mechanism is formed integrally with the holding member.   The light source device according to claim 1, wherein the prevention mechanism is provided on the entire inner wall of the mounting hole.   The light source device according to claim 2, wherein a plurality of the prevention mechanisms are provided on an inner wall of the mounting hole.   An optical scanning device comprising the light source device according to any one of claims 1 to 4. 6. An image forming apparatus, wherein the optical scanning device according to claim 5 is used as an image writing unit to an image carrier.

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