JP2010175712A - Multibeam light source unit, method of adjusting the same and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multibeam light source unit which is accurately mounted and in which the turning of mounted state is easily adjustable. <P>SOLUTION: The multibeam light source unit includes: a base member 30 which has a multibeam laser diode 31 with a stem 31b and a through hole 42 for housing the multibeam laser diode; and a leaf spring 40 having a long and substantially plate form, wherein each vicinity of both end parts of the leaf spring is supported by a base member 30, and the leaf spring presses and energizes the back face of the stem 31b of the multibeam laser diode 31 inserted into the substantially central part of the through hole 42. The multibeam laser diode 31, pressed and fixed onto the base member 30 by the spring force of the leaf spring 40, is adjustable in turning direction around an optical axis by releasing the fixation by pressing the leaf spring 40 to elastically deform to bend the leaf spring 40 at the part in the vicinity of the multibeam laser diode in the direction opposite to the emission direction of the multibeam laser. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multi-beam light source unit used in an image forming apparatus such as a digital copying machine or a laser printer, an adjustment method thereof, and an image forming apparatus using the same.

2. Description of the Related Art Conventionally, an image forming apparatus such as a digital copying machine or a laser printer is known in which a laser scanning optical device is mounted. In recent years, the laser scanning optical devices that use a multi-beam laser diode as a light source unit are becoming mainstream along with the demand for higher writing accuracy and higher writing speed.
FIG. 16 shows a schematic configuration of the housing 56 of the image forming apparatus main body with the multi-beam light source unit 19 in which the light source unit 1 is incorporated. Reference numeral 4 denotes a photoreceptor (also referred to as an image recording medium). A laser scanning optical device 57 is mounted on the housing 56, and the scanning optical system 57 is roughly composed of the polygon mirror 2 and the fθ lens 3. An opening 64 extending in a direction along the main scanning direction Q1 is formed on one side wall of the housing 56. FIG. 17 is a schematic diagram schematically showing the arrangement of the light source unit 1, the laser scanning optical device 57, and the like, where 1 is a light source unit, 2 is a polygon mirror, 3 is an fθ lens, and 4 is a photoconductor. The photosensitive member 4 is rotationally driven in the sub-scanning direction Q2, and the surface (also referred to as an image recording surface) 4a is irradiated with a laser beam in the main scanning direction Q1. The light source unit 1 is generally composed of a multi-beam laser diode 31 and a collimating lens 6.

The bottom wall of the housing 56 is provided with a positioning reference portion for mounting the bracket 20 to which the multi-beam light source unit 19 is assembled, and a pair of positioning pins and a pair of screw holes (appear in the figure). Not) is formed. As shown in FIG. 16, the bracket 20 integrated with the light source unit 19 has its bottom surface serving as a positioning reference surface abutted against the reference surface of the positioning reference portion and positioned by a positioning pin. It is fixed to.
The multi-beam laser diode 31 emits a multi-laser beam P from a plurality of light emitting points. The multi-laser beam P is converted into a parallel light beam by the collimating lens 6. The multi-laser beam P is reflected by the polygon mirror 2 and applied to the surface (image recording surface) 4a of the photosensitive member 4, and four beam spots 11 are formed on the photosensitive surface 4a.

The polygon mirror 2 and the fθ lens 3 constitute a part of the scanning optical system, and the multi-laser beam P is a sub laser beam orthogonal to the main scanning direction Q1 on the surface 4a of the photosensitive member 4 as shown in FIG. Scanning is performed in the main scanning direction Q1 with a predetermined pitch X1 in the scanning direction Q2. In this type of laser scanning optical device, the surface 4a of the photoconductor 4 is scanned simultaneously in a large number of rows, and writing is performed on the surface 4a of the photoconductor 4. The four beam spots 11 are substantially aligned in the sub-scanning direction Q2 on the surface 4a of the photosensitive member 4 because each light emitting point of the multi-beam laser diode 31 is adjusted in the sub-scanning direction Q2.
In the laser scanning optical apparatus, the diameter of the beam spot 11 on the surface 4a of the multi-laser beam P, the collimation property, and the adjacent beam spot are related to the higher accuracy of writing and the higher speed of writing. 11 is required to improve the accuracy of the pitch X1 in the sub-scanning direction Q2 and the writing start position in the main scanning direction Q1. The accuracy of the writing start position is increasingly demanding under the demand for higher image quality.

By the way, the multi-beam laser diode 31 has a light emitting portion 7 therein as shown in FIG. The light emitting unit 7 is provided with a plurality of light emitting points, for example, four light emitting points 7a to 7d. The light emitting points 7a to 7d are arranged at intervals on the virtual straight line Q3 that is originally designed. The virtual straight line Q3 is given by connecting sharp points 9a and 10a of a pair of acute-angle notches 9 and 10 formed in the metal stem 31b of the multi-beam laser diode 31.
In the conventional multi-beam laser diode 31 of this type, when a multi-laser beam is projected onto the surface 4a of the photosensitive member 4 at intervals of the light emitting points 7a to 7d, the pitch X1 of the beam spot 11 in the sub-scanning direction Q2 is projected. Is larger than the design. Therefore, as shown in FIG. 20, the light of the scanning optical system (not shown) is light so that the arrangement direction Q3 (virtual straight line) of the beam spot 11 is inclined with respect to the main scanning direction Q1 on the surface 4a of the photosensitive member 4. By rotating and adjusting the multi-beam laser diode 31 around the axis, the pitch X1 in the sub-scanning direction Q2 is adjusted, and the writing density (recording density) in the sub-scanning direction Q2 is increased to improve the image quality.

However, if the multi-beam laser diode 31 is rotationally adjusted so that the arrangement direction (virtual straight line) Q3 of the beam spot 11 is obliquely shifted with respect to the sub-scanning direction Q2, the writing density is improved at the same time. When writing is performed by driving 7a to 7d, the writing start position in the main scanning direction Q1 of the beam spot 11 on the surface 4a of the photosensitive member 4 is shifted, and the image quality is deteriorated.
Therefore, in this type of laser scanning optical apparatus, in order to align the writing start position on the surface 4a of the photosensitive member 4 for each beam spot, for example, the detection sensor 12 for detecting the scanning position of each laser beam is provided for each laser beam. It arrange | positions corresponding to every beam and controls the light emission of each light emission point 7a-7d based on the light reception timing of each detection sensor 12. FIG.
That is, the light emission control of each of the light emitting points 7a to 7d is performed after the time t0 ′ from the detection time of each beam spot 11 after the head beam spot 11 is detected at time t = t0, so that the surface 4a of the photoconductor 4 is applied. The writing start positions in the main scanning direction Q1 are aligned.

Further, instead of providing the detection sensors 12 corresponding to the respective light emitting points 7a to 7d, the detection sensors 12 are provided corresponding to the beam spot 11 that precedes the main scanning direction Q1 as shown in FIG. At the same time, temporal deviations t1, t2, and t3 of each beam spot 11 are obtained in advance, and a delay control circuit (not shown) is used to detect the most preceding beam spot 11 from the detection time by the detection sensor 12, as shown in FIG. By delaying the light emission of the remaining light emission points 7b to 7d in correspondence with the temporal deviation, the beam spot 11 at the writing start position on the surface 4a of the photosensitive member 4 is sub-charged as shown in FIG. They are aligned in the scanning direction.
Further, if the light emitting points 7a to 7b of the multi-beam laser diode 31 are present on the virtual straight line Q3 defined by the pair of notches 9 and 10, they are set in the scanning optical system based on the notches 9 and 10. The multi-beam laser diode 31 has the light emitting points 7a to 7d on the virtual straight line Q3 without error due to an error in the manufacturing process. Riding is rare.
As shown in FIG. 22, even if there is an arrangement direction (straight line) Q4 connecting the light emitting points 7a to 7d, the arrangement direction Q4 and the virtual line Q3 are slightly inclined, and some adjustment is required. Therefore, it is difficult to align the arrangement direction of the light emitting points 7a to 7d with the direction of the design reference straight line. Here, the symbol θ indicates the inclination angle.

  Therefore, for example, as disclosed in Patent Document 1, a multi-beam laser diode 31 (reference number 5 in Patent Document 1) is provided in the main body of the image forming apparatus on which the scanning optical system is mounted with the configuration shown in an exploded perspective view in FIG. ), The terminal member 48 of the multi-beam laser diode 31 is passed through the leaf spring (pressing spring piece) 40 so that the arrangement direction Q4 is at a predetermined angle with respect to the sub-scanning direction Q2. When fixing to the base member 30, the optical system is caused to emit light, and the rotation is adjusted around the optical axis, and the pitch X1 after being fixed to the base member 30 with the screw 43 is confirmed. Loosening, readjustment, and repeated adjustment until the value falls within a predetermined value have been adopted. Note that the multi-beam light source unit and the rotation posture adjustment substantially similar to those described above are also disclosed in detail in Patent Document 2.

As described above, in order to mount a multi-beam laser diode in a multi-beam light source unit, the position of the light-emitting point changes depending on the mounting angle of the multi-beam laser diode, and therefore the arrangement of the light-emitting points is planned by design. It is desirable that the multi-beam laser diodes can be rotated and adjusted around the optical axis so that they can be arranged so that they can be fixed. Until now, as shown in Patent Document 1, as shown in FIG. In order to press and fix the beam laser diode, the plate spring has been fastened with a screw. However, when the screw is fastened with the screw, the multi-beam laser diode often moves and the mounting angle varies, leading to an increase in man-hours. There was an inconvenience.
This is because the leaf spring 40 is twisted when the first or second screw 43 is seated as shown in FIGS. 24 (a) and 24 (b) by screwing the leaf spring 40, and the multi-beam laser diode. It is thought that the phenomenon that the attachment angle of 31 fluctuated occurred.
The present invention has been made in view of the above circumstances, and is configured so as not to cause pitch fluctuation caused by screwing when fixing the multi-beam light emitting element, so that an accurate mounting state can be obtained and at the time of adjustment. It is an object of the present invention to provide a multi-beam light source unit that can easily adjust the rotation of the multi-beam light emitting element attached state, and an apparatus using the same.

  In order to solve the above problems, the invention according to claim 1 is a cylindrical main body capable of emitting a multi-laser beam from a plurality of light emitting points formed in a line and substantially concentric with the optical axis of the multi-laser beam. And a light emitting element having a stem having a larger diameter than the cylindrical main body, and a base member having a through hole for accommodating a light emitting element having an inner diameter larger than the cylindrical main body and smaller than the stem. In the multi-beam light source unit, the vicinity of both end portions in the longitudinal direction in a substantially long plate shape is supported by the base member, and the back surface of the stem of the light emitting element fitted in the through hole is pressed in the substantially central portion. The light emitting element is pressed and fixed to the base member by a spring force of the elastic member, and a predetermined portion of the elastic member is pressed and elastically deformed during positioning adjustment. The light emitting element is bent in the direction opposite to the multi-laser beam emission direction so that the positioning of the light emitting element is released and the rotation of the light emitting element around the optical axis can be adjusted. It is characterized by that.

According to a second aspect of the present invention, in the multi-beam light source unit according to the first aspect, when the positioning of the light emitting element is adjusted, the elastic member is pressed from both ends in the longitudinal direction to be elastically deformed to be near the light emitting element. This portion is bent in the direction opposite to the multi-laser beam emission direction, so that the rotation adjustment of the light emitting element around the optical axis is possible in a state where the positioning and fixing of the light emitting element is released.
According to a third aspect of the present invention, in the multi-beam light source unit according to the second aspect, the elastic member has a long hole in the vicinity of both ends in the longitudinal direction, and pressurizes from both ends in the longitudinal direction. The base member engages with the elongated hole and guides the leaf spring in the longitudinal direction to define the position in the width direction. It has a positioning pin for supporting the spring and fixing the light emitting element.

According to a fourth aspect of the present invention, in the multi-beam light source unit according to the first aspect of the present invention, the elastic member is a leaf spring in which extended tongue pieces formed to extend at both lateral edges are formed. When the positioning of the light emitting element is adjusted, the protrusions are formed so as to protrude from the edge of the base member in the width direction edge by pressing the tips of the extended tongue pieces in the multi-laser beam emission direction. It is elastically deformed by pressing against the stripes or protrusions, and the portion in the vicinity of the light emitting element is bent to the side opposite to the multi-laser beam emitting direction so that the positioning and fixing of the light emitting element is released. It is characterized by being able to adjust the rotation.
The invention according to claim 5 is the method of adjusting a multi-beam light source unit according to any one of claims 1 to 4, wherein the elastic member is pressurized in a predetermined manner, and the light emitting element is elastically deformed. The elastic member in the vicinity is bent to the opposite side to the multi-laser beam emission direction, and the rotation adjustment around the optical axis of the optical element is performed in a state where the positioning and fixing of the light emitting element is released.
A sixth aspect of the present invention is an image forming apparatus, wherein the multi-beam light source unit according to any one of the first to fourth aspects and a light beam from the multi-beam light source unit are deflected to perform the deflection. And a scanning optical system for guiding the emitted light beam onto the surface to be scanned.

  According to the present invention, there is provided a multi-beam light source unit capable of obtaining an accurate mounting state without being affected by pitch fluctuations regardless of screwing when the multi-beam light emitting element is fixed and easily adjusting the rotation of the mounting state during adjustment. It is possible to provide a conventional image forming apparatus.

It is a disassembled perspective view of the multi-beam light source unit concerning 1st Embodiment of this invention. It is a rear view of the same multi-beam light source unit. It is the disassembled perspective view which looked at the multi-beam light source unit and the bracket from the back side. FIG. 2 is a longitudinal sectional view of a main part in which a part of the light source unit in FIG. 1 is omitted. FIG. 2 is a longitudinal sectional view of a main part in which a part of the light source unit in FIG. 1 is omitted. FIG. 2 is a longitudinal sectional view of a main part in which a part of the light source unit in FIG. 1 is omitted. FIG. 2 is a longitudinal sectional view of a main part in which a part of the light source unit in FIG. 1 is omitted. FIG. 2 is a longitudinal sectional view of a main part in which a part of the light source unit in FIG. 1 is omitted. FIG. 2 is a longitudinal sectional view of a main part in which a part of the light source unit in FIG. 1 is omitted. It is a disassembled perspective view of the light source unit which concerns on 2nd Embodiment. It is a rear view of the light source unit which concerns on 2nd Embodiment. It is a disassembled perspective view of the light source unit which concerns on 3rd Embodiment. It is a rear view of the light source unit which concerns on 3rd Embodiment. It is a transversal direction sectional view of the principal part which abbreviate | omitted a part of light source unit shown in FIG. FIG. 14 is a cross-sectional view in the short direction of the main part of the light source unit shown in FIG. 13. 1 is a diagram illustrating a known general configuration of a housing of an image forming apparatus main body. It is a schematic diagram which shows schematic structure of a scanning optical system. It is a schematic diagram which shows the arrangement | sequence state of the beam spot on an image recording surface. It is a schematic diagram for demonstrating the arrangement state of the light emission point of a multi-beam laser diode. It is a figure for demonstrating an example of control of the write-in start position on an image recording surface. It is a figure for demonstrating the other example of control of the write-in start position on an image recording surface, (a) is a figure which shows the relationship between the arrangement direction of a beam spot, and a write-in start position, (b) is the light emission. It is a timing diagram for demonstrating the light emission timing of a point. It is a figure for demonstrating the inclination of the arrangement direction of the light emission point of a multi-beam laser diode, and a design reference | standard direction. It is a disassembled perspective view of a known beam light source unit. (A) And (b) is a figure explaining the pitch fluctuation generation resulting from the screwing at the time of light emitting element fixation.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment, the multi-beam light source unit 19 is used by being attached to the housing of the image forming apparatus main body similar to that of FIG. 16 described above. The housing etc. will not be described in order to avoid duplication. Various types of image forming apparatuses are already known, and the type is not selected for applying the present invention.
Only the multi-beam light source unit according to the present invention will be described below. FIG. 1 is an exploded perspective view of a multi-beam light source unit 19 according to the present invention as seen from the back side. FIG. 2 is a rear view of the assembled light source unit 19. FIG. 3 is a (partly) exploded perspective view of the multi-beam light source unit 19 and the bracket 20 as viewed from the back side. These are substantially the same as those disclosed in Patent Document 1, and the attachment mechanism of the multi-beam laser diode 31 is different. In FIG. 3, the same reference numerals are given to the same parts as those disclosed in Patent Document 1, and the description of the configuration that is not related to the features of the present invention will be omitted, and only the main part will be described.

In the figure, reference numeral 30 denotes a base member. The base member 30 is formed with a pair of bosses 41a for attaching the plate springs 40 and a multi-beam laser diode attachment part 41 for attaching the multi-beam laser diodes 31. The multi-beam laser diodes 31 are made of plate springs. 40 is fixed in a predetermined posture. The multi-beam light source unit 19 is attached to the mounting bracket 20 as in the case of Patent Document 1 (see FIG. 3), but this point is detailed in Patent Document 1 and will not be described in this specification.
The multi-beam laser diode 31 is the same as that shown in FIG. 19 and has the light emitting part 7 therein. As described above, the light emitting section 7 is provided with a plurality of light emitting points, for example, four light emitting points 7a to 7d. As described above, the light emitting points 7a to 7d are arranged on the virtual line Q3 that is originally designed to be spaced from each other, and the virtual line Q3 at this time is the multi-beam laser. It is given by connecting sharp points 9a, 10a of a pair of acute-angled notches 9, 10 formed in the metal stem 31b of the diode 31.

A through-hole 42 concentric with the designed optical axis is formed in the multi-beam laser diode mounting portion 41, and a back-side opening of the through-hole 42 is formed in the abutting reference surface 42b of the stem 31b. The inner diameter of the through hole (attachment reference hole) 42 is larger than the cylindrical main body 31a and smaller than the stem 31b, and the depth of the through hole (attachment reference hole) 42 is determined by pressing the stem 31b against the reference surface 42b. The back surface of the pressing plate is protruded from the back surface of the pressing plate mounting portion 41.
The leaf spring 40, which is an elastic member that engages and is fixed to the mounting portion 41, has a pressing spring piece 40a at the periphery of the through hole at the center, and the base spring 30 on both ends in the longitudinal direction of the leaf spring 40. A U-shaped through hole 40c and a bent end piece (bent portion) 40e which are wider than the outer diameter of the boss 41a and narrower than the outer diameter of the screw 43 are provided.

Subsequently, the adjustment and fixing procedure will be described.
4 to 9 are diagrams for explaining a series of procedures for adjusting and fixing the multi-beam laser diode 31 according to the present invention. For the work, an appropriate chuck (not shown) is used as a jig for pressurizing the socket 49 and the bent end piece 40e of the leaf spring 40 for connecting the terminal 48 of the multi-beam laser diode 31 to the control board of the multi-beam laser diode. ) And prepare. The multi-beam laser diode emits light, irradiates the polygon mirror 2 through the collimator lens 6, measures the beam pitch X 1 at a position on the photoconductor 4 after passing through the fθ lens 3, and adjusts the mounting angle of the multi-beam laser diode 31. .
First, as shown in FIG. 4, the terminal 48 of the multi-beam laser diode 31 is held by the socket 49 through the through hole 40 f of the leaf spring 40. Next, as shown in FIG. 5, using a chuck (not shown) as a jig for pressurizing the bent end piece 40e of the leaf spring 40 or with fingers of the hand, the bent end piece 40e of the leaf spring 40 is fixed at both ends. Is pressed in the direction of arrow F, and is bent and deformed until the interval between the U-shaped through holes 40 c becomes smaller than the interval between the bosses 41 a provided in the base member 30.
In this way, with the leaf spring 40 bent, the multi-beam laser diode 31, the socket 49, and the leaf spring 40 are moved in the direction of arrow A. As shown in FIG. 40c is hung on the outer periphery of the boss 40a of the base member 30, and a screw 43 is attached to the boss 40a to be seated. Further, as shown in FIG. 7, the socket 49 is rotated around the designed optical axis, and the angle of the multi-beam laser diode 31 is adjusted.

After adjusting the angle of the multi-beam laser diode 31, as shown in FIG. 8, the pressure in the direction of arrow F applied to the bent end piece 40e of the leaf spring 40 is released, and the deflection of the leaf spring 40 is released in the direction of arrow E. . By releasing this bending, the pressing spring piece 40a of the leaf spring 40 presses the stem 31b of the multi-beam laser diode 31, so that the stem 31b is pushed out in the direction of arrow D and hits the upper surface 42 of the multi-beam laser diode mounting portion 41. Positioning is fixed. Finally, as shown in FIG. 9, the socket 49 is pulled up in the direction of arrow I, the socket 49 is removed from the terminal 48 of the multi-beam laser diode 31, and the multi-beam laser diode 31 as shown in the perspective view of FIG. A multi-beam light source unit whose angle of attachment is adjusted and maintained.
As described above, the multi-beam laser diode is fixed by using the plate spring that is bent in the direction opposite to the emission direction of the multi-laser beam by pressurizing the bent end pieces 40e at both ends of the plate spring 40, thereby When adjusting the rotation of the laser diode, press the leaf spring from both ends in the longitudinal direction to deflect the part in contact with the light emitting element to the side opposite to the emission direction of the multi-laser beam, release it, and rotate it to adjust the angle. After the adjustment, the bending of the leaf spring is returned and the multi-beam laser diode is positioned and fixed.By adjusting the rotation of the multi-beam laser diode, it can be fixed without shifting from the value adjustment position by screwing the leaf spring. Accurate positioning is possible. In addition, since readjustment of the multi-laser diode is not necessary, the number of man-hours for adjustment is reduced, and the production cost of the multi-beam light source unit can be reduced.

[Second Embodiment]
Further, in the present invention, as described above, in addition to the structure in which the plate spring 40 is hooked on the seating surface of the screw 43, a claw 50 for hooking the plate spring on the base member 30 is provided as shown in FIGS. In addition, a structure that is hung on the convex through hole 40d provided in the leaf spring 40 is also conceivable.
Also in the multi-beam light source unit of the second embodiment, as in the first embodiment, the socket 49 and the bent end of the leaf spring 40 for connecting the terminal 48 of the multi-beam laser diode 31 to the control board of the multi-beam laser diode. A chuck for pressurizing the piece 40e is prepared (see the similar FIG. 4), and the multi-beam laser diode is caused to emit light as described above, irradiates the polygon mirror 2 through the collimator lens 6, and the fθ lens 3 The beam pitch X1 is measured at a position on the photoconductor 4 after transmission, and the mounting angle of the multi-beam laser diode 31 is adjusted.
In the case of this embodiment, when the leaf spring 40 is fixed to the base member, the bent end piece 40e is pressed from the direction of the arrow F in the same manner as shown in FIG. It is necessary to let Further, at this time, the pawl 50 is deformed until the gap between the stepped portions 41h on the convex through holes 40d provided on the left and right sides on the leaf spring 40 becomes narrower than the gap between the claws 50. The leaf spring 40 can be fixed to the base member 30 by releasing the pressure applied from the direction of the arrow F after passing through the 40 convex through holes 40d.

[Third Embodiment]
Further, in the third embodiment shown in FIGS. 12 and 13, on the ridge line of the multi-beam laser diode mounting portion 41 of the base member 30, a protrusion having a certain height parallel to the longitudinal direction of the leaf spring 40 (ridge on the ridge line). Article) 41b is provided protruding. It is sufficient that the ridge line protrusion 41 b extends at least in the vicinity of the multi-beam laser diode mounting portion 41.
Further, the leaf spring 40 is provided with a short-side protruding tongue piece 40g at both ends in the short direction at a substantially central portion of the leaf spring 40. The length of the short-side protruding tongue piece 40g is such that both ends of the short-side protruding tongue piece 40g come outside the ridge line protrusions (projections) 41b provided on the base member 30.
At this time, as shown in FIGS. 14 and 15, both ends of the short-side protruding tongue piece 40g are pressed in the direction of the arrow J so as to come into contact with the protrusion 41b of the base member 30, and the protrusion 41b becomes a fulcrum. The pressing spring piece 40a of the leaf spring 40 that presses the stem 31b is raised by bending the portion in contact with the laser diode 31 to the side opposite to the emission direction of the multi-laser beam, and the multi-beam laser diode 31 is unlocked and rotated. Adjustment is possible. In addition, it replaces with the ridgeline top protrusion 41b, and the same effect is acquired even if it provides one protrusion in a width direction edge part, or several protrusion along an edge.

As described above, according to the present invention, there is no occurrence of pitch fluctuation caused by screwing at the time of fixing the conventional multi-beam light emitting element, and an accurate mounting state can be obtained and the multi-beam light emitting element mounting state can be obtained at the time of adjustment. Can be obtained, and a multi-beam light source unit and an image forming apparatus using the same can be obtained.
The present invention is not limited by the above-described embodiments, and various modifications can be made. For example, in each embodiment, a pressing spring piece 40a that presses and urges the back surface of the stem of the light emitting element fitted in the through hole is provided at a substantially central portion of the leaf spring 40 as an elastic member. Instead of this, an annular protrusion may be formed. Alternatively, only the through hole may be formed, and the back edge portion of the stem 31b may be pressed with an appropriate spacer or washer interposed.

  DESCRIPTION OF SYMBOLS 1 Light source unit, 6 Collimate lens, 19 Multi-beam light source unit, 30 Base member, 30z Claw, 31 Multi-beam laser diode, 31a Cylindrical main-body part, 31b Stem, 40 Leaf spring, 40a Pressing spring piece, 40d Convex-shaped through-hole 40e bent end piece, 40g short side protruding tongue piece, 41 multi-beam laser diode mounting part, 41a boss, 41b protrusion (ridge on the ridge line), 40g short side protruding tongue piece, 41h stepped part, 42 fitting Hole (through hole), 43 screws, 48 terminals (multi-beam laser diode), 49 socket, 50 claws

JP 2001-228418 A Japanese Patent No. 4132598

Claims (6)

A multi-laser beam can be emitted from a plurality of light-emitting points formed in a line, and has a cylindrical main body substantially concentric with the optical axis of the multi-laser beam, and a light emission having a stem having a larger diameter than the cylindrical main body. In a multi-beam light source unit comprising an element and a base member having a through-hole for accommodating a light-emitting element having an inner diameter larger than the cylindrical main body and smaller than the stem,
A substantially long plate-like shape is supported by the base member in the vicinity of both end portions in the longitudinal direction, and has an elastic member that presses and urges the back surface of the stem of the light emitting element fitted in the through hole at a substantially central portion. The light emitting element is normally pressed and fixed to the base member by the spring force of the elastic member. During positioning adjustment, a predetermined portion of the elastic member is pressed and elastically deformed so that a portion near the light emitting element is multi-laser. A multi-beam light source unit configured to be capable of adjusting the rotation of the light emitting element around the optical axis in a state in which the positioning and fixing of the light emitting element are released by bending in a direction opposite to the beam emitting direction.   At the time of positioning adjustment of the light emitting element, the elastic member is pressed from both ends in the longitudinal direction to be elastically deformed, and a portion in the vicinity of the light emitting element is bent to the side opposite to the multi-laser beam emitting direction to fix the positioning of the light emitting element. 2. The multi-beam light source unit according to claim 1, wherein the multi-beam light source unit is configured to be capable of adjusting rotation around the optical axis of the light emitting element in the unwound state. The elastic member has a long hole in the vicinity of both ends in the longitudinal direction, and consists of a leaf spring in which bent end pieces are formed at both ends in order to pressurize from both ends in the longitudinal direction.
The base member engages with the elongated hole to guide the leaf spring in the longitudinal direction to define the position in the width direction, and includes a positioning pin for supporting the leaf spring and fixing the light emitting element. The multi-beam light source unit according to claim 2, wherein the multi-beam light source unit is provided. The elastic member comprises a leaf spring in which extended tongue pieces formed to extend on both side edges in the short direction are formed,
At the time of positioning adjustment of the light emitting element, a protrusion or protrusion that is formed so as to protrude from the edge in the width direction edge of the upper surface of the base member by pressing each distal end portion of the extending tongue piece in the multi-laser beam emitting direction. The light emitting element is elastically deformed, and the portion near the light emitting element is bent to the side opposite to the multi-laser beam emitting direction so that the positioning of the light emitting element is released and the rotation adjustment of the light emitting element around the optical axis is adjusted. The multi-beam light source unit according to claim 1, wherein the multi-beam light source unit is configured to be possible. It is the adjustment method of the multi-beam light source unit as described in any one of Claims 1 thru | or 4, Comprising:
The elastic member is pressed in a predetermined manner, and the portion near the light emitting element is bent by elastic deformation to the opposite side to the multi-laser beam emitting direction so that the positioning and fixing of the light emitting element is released. An adjustment method for a multi-beam light source unit, characterized in that rotation adjustment around an axis is performed.   5. A multi-beam light source unit according to claim 1, and a scanning optical system that deflects a light beam from the multi-beam light source unit and guides the deflected light beam onto a surface to be scanned. An image forming apparatus.

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