JP2006072136A - Light source apparatus and scanning optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scanning optical apparatus and an image forming apparatus in which a semiconductor laser is easily built in a driving circuit substrate. <P>SOLUTION: The scanning optical apparatus 3 is characterized by that the typical composition of the scanning optical apparatus, which emits laser light on the basis of an image information to a photoreceptor drum 46, is a semiconductor lasers 39 which emit the laser light, and a driving circuit substrate 37 which controls the semiconductor lasers 39, and the same number of holes as the semiconductor lasers 39 are drilled on the driving circuit substrate 37, and the wiring of the semiconductor lasers 39 is performed through the holes 57. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a scanning optical device mounted on an electrophotographic apparatus such as a laser beam printer, a digital copying machine, or a digital FAX, and a light source device mounted on the apparatus.

  Conventionally, in a scanning optical device using a semiconductor laser having a plurality of light emitting points therein, it is necessary to align a plurality of laser beams generated from the semiconductor laser at predetermined intervals in the sub-scanning direction on the image carrier. is there. Therefore, the semiconductor laser is rotated and adjusted around the optical axis in the process of assembling the apparatus. As an example of a method of assembling a light source device by performing such adjustment, a semiconductor laser is adjusted around the optical axis, and then the semiconductor laser is press-fitted into a laser holder, and further, a drive circuit for driving the semiconductor laser with leads of the semiconductor laser There is a method of attaching a drive circuit board to a laser holder through a hole in the board (see Patent Document 1).

  When assembling by such a method, it is necessary that the position of the lead of the semiconductor laser after the rotation adjustment and the position of the hole on the drive circuit board are aligned. Therefore, as shown in FIG. 11, the position of the hole 257 on the drive circuit board 37 is also rotated in advance around the optical axis (angle θ in FIG. 11), or the shape of the lead 58 is corrected and the position on the drive circuit board 37 is corrected. It is aligned with the position of hole 257. In FIG. 11, reference numeral 39 is a semiconductor laser, 40 is a laser holder, 55 is a conduction pattern provided on the drive circuit board 37, and 56 is solder.

  As shown in FIGS. 12 and 13, a light source device in which tapered surfaces C and D are provided on a laser holder 40 or a drive circuit board 37 has been proposed (see Patent Document 2 and Patent Document 3). By inserting the lead 58 of the semiconductor laser 39 along the tapered surfaces C and D, the lead 58 of the semiconductor laser 39 can be easily passed through the hole 257 on the drive circuit board 37.

  On the other hand, recently, an image forming apparatus including semiconductor lasers for four colors of yellow, magenta, cyan and black has been proposed in order to form a color image at high speed. As shown in FIG. 14, a light source device has also been proposed in which at least two (two in the figure) semiconductor lasers 39 among four semiconductor lasers are attached to one drive circuit board 37.

JP 2001-100128 A JP 09-181396 A JP 2002-006248 A JP 2003-131158 A

  However, in the semiconductor laser 39 having a plurality of light emitting points therein, the number of leads 58 increases according to the number of light emitting points. For example, a semiconductor laser having one light emitting point inside requires two leads. When a photodiode that performs feedback control of the amount of laser light is provided inside, a total of three diodes are required with the anode side or cathode side in common with the laser diode.

  Further, every time the number of light emitting points increases, even if either the anode side or the cathode side is shared, at least one lead is added. For example, when there are two light emitting points and a photodiode is provided inside, there are four leads.

  Further, as shown in FIG. 11, the drive circuit board 37 for driving the semiconductor laser 39 is provided with holes 257 and circuit patterns 55 for passing the leads 58 for the number of the leads 58. For this reason, when the number of the leads 58 increases, it becomes difficult to assemble all the holes 257 through the leads 58, and the assembling workability is extremely deteriorated.

  Further, if the number of leads 58 increases, it becomes difficult in design to provide the same number of holes 257 as the leads 58 in a limited space on the drive circuit board 37. If the diameter of the hole 257 is reduced to cope with this, the lead 58 becomes more difficult to pass through the hole during assembly.

  On the other hand, if the drive circuit board 37 has enough space and the lead 58 has a sufficient length, the lead 58 is widened and formed, and the holes 257 and the pattern 55 are formed on the drive circuit board 37 at appropriate intervals. May be arranged. However, if the lead 58 is lengthened, the high-speed response of the semiconductor laser 39 is deteriorated according to the length of the lead 58, and the high resolution (high dpi) or high speed of the printer is hindered. Further, the stem dimension and the lead 58 dimension are required to be equal to or larger than a predetermined value, so that the inexpensive general-purpose semiconductor laser 39 cannot be used, which may increase the cost of the entire image forming apparatus.

  In addition to the above problems, the scanning optical device described in Patent Document 2 (Japanese Patent Laid-Open No. 09-181396) shown in FIG. 12 has the following problems. As shown in FIG. 12, the lead 58 is formed while being rubbed against the tapered surface C of the laser holder 40 during assembly. The semiconductor laser 39 is very sensitive to static electricity as compared with an ordinary IC or the like. For this reason, the friction may cause damage such as static electricity to the semiconductor laser 39.

  Further, when the laser chip is damaged by static electricity or the like, the characteristics are not always deteriorated immediately. For example, there is a possibility that the semiconductor laser 39 that has been lit without problems at the time of assembling the printer will not shine without achieving a predetermined life after shipment.

  In the printer assembly process, sufficient countermeasures against static electricity are taken in consideration of these laser characteristics. However, a configuration that may cause electrostatic damage to the semiconductor laser 39 from the time of design should be avoided.

  Similarly, in the scanning optical device described in Patent Document 3 (Japanese Patent Laid-Open No. 2002-006248) shown in FIG. 13, the lead 58 is formed while being rubbed against the tapered surface D of the drive circuit board 37 during assembly. To do. For this reason, the friction may cause damage such as static electricity to the semiconductor laser 39.

  Further, in the scanning optical device described in Patent Document 4 (Japanese Patent Application Laid-Open No. 2003-131158) shown in FIG. 14, that is, in a configuration in which a plurality of semiconductor lasers are attached to a single drive circuit board, each semiconductor laser emits a plurality of lights. In the case of having a point, it is necessary to adjust the rotation of each semiconductor laser. If the drive circuit board is divided for each semiconductor laser, even if the semiconductor laser is rotated and adjusted, if the drive circuit board is also rotated, the position of the lead of the semiconductor laser and the hole of the drive circuit board can be aligned. In the case of a configuration in which a plurality of semiconductor lasers are attached to one driving circuit board, the second driving circuit board is rotated around the optical axis of the first semiconductor laser according to the rotation adjustment angle of the first semiconductor laser. Since the positional relationship between the lead of the semiconductor laser and the hole of the drive circuit board greatly varies, the drive circuit board cannot be rotated.

  Further, since the rotation adjustment angles of the respective semiconductor lasers are different, there is a relative angle difference between the plurality of semiconductor lasers after the rotation adjustment. Therefore, when the relative angle difference exceeds the backlash between the lead 58 and the hole 257, the lead 58 does not pass through the hole 257 and cannot be assembled. In order for the lead 58 to pass through the hole 257, the lead 58 needs to be bent.

  There is also a method in which the semiconductor laser 39 is first soldered to the drive circuit board 37 at an angle at which the lead 58 passes through the hole 257, and then the scanning line pitch interval on the photosensitive drum is forcibly adjusted. In this method, the semiconductor laser 39 is forcibly twisted with respect to the drive circuit board 37. However, the positional relationship between the light emitting point of the semiconductor laser 39 and the collimator lens is adjusted with high accuracy on the order of several μm to several tens of μm. For this reason, when a load is applied to the semiconductor laser 39, there is a possibility that this adjustment value will be out of tolerance.

  Further, the scanning optical devices described in Patent Documents 1 and 4 (Japanese Patent Laid-Open Nos. 2001-100128 and 2003-131158) have the following common problems. The base of the lead 58 is insulated and sealed using low melting point glass or the like except for the common terminal. However, if a load is applied to the root of the lead 58, the low melting point glass may crack and the airtightness inside the semiconductor laser 39 may be broken.

  Then, except for the open package type semiconductor laser 39 which does not need to maintain the internal airtightness, the following problems occur. For example, moisture enters inside from cracks in the low-melting glass, current leaks, and the amount of light of the semiconductor laser 39 decreases or the laser chip deteriorates.

  Further, the emission end face of the laser chip is oxidized, so that the amount of light of the semiconductor laser 39 is reduced or the laser chip is deteriorated. In addition, the amount of light of the semiconductor laser 39 or the laser chip deteriorates due to a current leak caused by a whisker of solder material or a current leak caused by scattering of the conductive adhesive.

  Then, due to a decrease in the amount of light of the semiconductor laser 39 or deterioration of the laser chip, there is a risk that the print density may be reduced during the operation of the image forming apparatus or that the image forming operation may be stopped in some cases.

  In the open package type semiconductor laser 39, taking these problems into consideration, an anti-oxidation film is applied to the laser chip emitting end face, or a solder material or conductive adhesive that does not cause a risk of whisker or scattering is devised. Yes.

  The present invention has been made in view of the above-described problems, and its purpose is to facilitate assembly of a semiconductor laser to a drive circuit board, to prevent deterioration of the semiconductor laser, and high-speed response of the semiconductor laser. It is an object of the present invention to provide a scanning optical device and an image forming apparatus capable of maintaining good image quality, reducing the cost of the entire image forming apparatus, and allowing a lead to pass through a hole even if the rotation angle of a semiconductor laser is slightly deviated.

  The light source device of the present invention for solving the above-described problems is a light source device having a semiconductor laser that emits laser light, and a drive circuit board that is connected to a plurality of terminals of the semiconductor laser and drives the semiconductor laser. The drive circuit board is provided with at least one hole through which the terminal of the semiconductor laser passes, and two or more of the terminals pass through one hole.

  The scanning optical device of the present invention deflects and scans a semiconductor laser that emits laser light, a drive circuit substrate that is connected to a plurality of terminals of the semiconductor laser and drives the semiconductor laser, and laser light emitted from the semiconductor laser. In the scanning optical device having a scanning optical system, the drive circuit board is provided with at least one hole through which the terminal of the semiconductor laser passes, and two or more of the terminals pass through one hole. It is characterized by being.

  The terminal of the semiconductor laser can be easily passed through the hole of the drive circuit board. In particular, when the semiconductor laser has a plurality of light emitting points, the terminal of the semiconductor laser can be easily passed through the hole of the drive circuit board even if the rotation adjustment around the optical axis of the semiconductor laser is performed.

[First embodiment]
A first embodiment of a light source device and a scanning optical device according to the present invention will be described with reference to the drawings.

(Image forming device)
First, an image forming apparatus provided with a scanning optical device will be described. FIG. 2 is a configuration diagram of an image forming apparatus including the scanning optical device according to the present embodiment. As shown in FIG. 2, the respective laser beams LC, LM, LY, and LK modulated based on the image information are emitted from the respective scanning optical devices 3. Each emitted laser beam L irradiates the surfaces of the photosensitive drums 46C, 46M, 46Y, and 46BK, which are corresponding image carriers, to form a latent image. Each photosensitive drum 46 is uniformly charged by primary chargers 47C, 47M, 47Y, and 47BK. The latent images formed on the photosensitive drum 46 are visualized as cyan, magenta, yellow, and black images by developing units 34C, 34M, 34Y, and 34BK, respectively.

  Cyan, magenta, yellow, and black images visualized on the surfaces of the photosensitive drums 46C, 46M, 46Y, and 46BK are sequentially transferred onto a transfer material 45 that is conveyed on the transfer belt 44 with high accuracy. A color image is formed. The transfer belt 44 is suspended from a drive roller 42 connected to a drive motor (not shown) with small rotation unevenness, and is rotated with high accuracy by the drive rotation of the drive roller 42. The color image formed on the transfer material 45 is thermally fixed by the fixing device 43 and then discharged outside the apparatus by a discharge roller 48 or the like.

(Scanning optical device)
FIG. 3A and FIG. 3B are a top view and a side view of a scanning optical device provided in the image forming apparatus. As shown in FIG. 3, the scanning optical device 3 includes a laser unit 30 that is a light source device, a scanning optical system (polygon mirror 31, scanning lens 32), a folding mirror 33, an optical box 36 (36a, 36b), and a drive circuit board. It consists of 37.

  The two stripes of laser light emitted from the laser units 30C and 30M are scanned in different directions by the polygon mirror 31a. The laser beams scanned by the polygon mirror 31a pass through the scanning lenses 32C and 32M, are reflected by the folding mirrors 33C and 33M, and form images on the photosensitive drums 46C and 46M.

  In parallel with such a scanning optical system, similar scanning systems (laser units 30Y and 30BK, polygon mirror 31b, scanning lenses 32Y and 32BK, folding mirrors 33Y and 33BK) are provided. In this way, the scanning optical systems are arranged in parallel in two pairs, so that the scanning light is guided onto the four photosensitive drums 46C, 46M, 46Y, and 46BK.

  FIG. 4 is a configuration diagram around the light source device. As shown in FIG. 4, the laser unit 30 of this embodiment includes a collimator lens 38, a semiconductor laser 39, a laser holder 40, and a collimator barrel 41.

  The collimator lens 38 is bonded and fixed to the collimator barrel 41. The semiconductor laser 39 is press-fitted and fixed to the laser holder 40. The collimator barrel 41 is adjusted so that optimum collimated light can be obtained in the total three-dimensional direction of the optical axis direction and the plane XY direction perpendicular to the optical axis. Thereafter, the collimator barrel 41 is bonded and fixed to the laser holder 40 (unitized) to form the laser unit 30 in the adjusted state.

  The laser unit 30 is assembled to the optical box 36 using screws 35, springs 49, and the like. The leads (terminals) of the semiconductor laser 39 are electrically connected to the laser drive circuit board 37 by soldering or the like. The drive circuit board 37 supplies current to the semiconductor laser 39 and controls ON / OFF of light emission of the semiconductor laser 39. In the present embodiment, the drive circuit board 37 is fixed not to the laser holder 40 but to the optical box 36. However, the drive circuit board 37 is fixed to the laser holder 40, and the laser holder 40 is optically fixed. The structure fixed to the box 36 may be sufficient.

  FIG. 5 is a configuration diagram of the semiconductor laser 39 provided in the laser unit 30. As shown in FIG. 5, the semiconductor laser 39 includes a laser chip 50 having a light emitting point, a stem 51, a submount 52, a window cap 53, a photodiode 54, and leads 58.

  The laser chip 50 is an edge-emitting laser chip and is die-bonded to the stem 51 via a submount 52. Note that the laser chip 50 may be directly die-bonded to the stem 51. The photodiode 54 is directly die-bonded to the stem 51.

  An Au wire 62 or the like is bonded to the laser chip 50 or the photodiode 54 by ultrasonic waves or the like and is connected to the corresponding lead 58. Further, the laser chip 50, the photodiode 54 and the like are covered with a window cap 53 and protected from the outside.

  FIG. 1 is a diagram for explaining a connection state between a semiconductor laser and a drive circuit board. As shown in FIG. 1, one semiconductor laser 39 of the present embodiment has four leads 58. The drive circuit board 37 has the same number of holes 57 as the semiconductor laser 39. That is, one hole 57 corresponding to one semiconductor laser 39 is drilled. In the present embodiment, the hole 57 is a round hole, but the hole 57 is not limited to a round hole, and may be at least rotationally symmetric such as a regular polygon.

  When combining the semiconductor laser 39 and the drive circuit board 37, first, all four leads 58 are passed through the same hole 57 of the laser drive circuit board 37. Thereafter, the lead 58 is bent along the outer periphery of the hole 57. A pattern 55 connected to the semiconductor laser 39 is provided on the outer surface A (surface opposite to the semiconductor laser 39) of the laser drive circuit board 37. The pattern 55 is formed in an arc shape that is divided into four in accordance with the four leads 58 in the vicinity of the outer peripheral portion of the hole 57.

  The leading end side B of the lead 58 after bending is soldered to the arc-shaped portion of the pattern 55 with solder 56. The pattern 55 is connected to a driver IC (not shown) or a corresponding drive circuit (not shown). With this configuration, ON / OFF of light emission of the semiconductor laser 39 is controlled from the driver IC or the like via the pattern 55.

(Tilt of the flash point)
The semiconductor laser 39 of this embodiment is a multi-beam semiconductor laser in which the laser chip 50 has two light emitting points. The two light emitting points need to be tilted (adjusted for rotation) around the optical axis so as to form scanning lines on the photosensitive drum 46 at predetermined intervals.

  FIG. 6 is an explanatory diagram of a connection state between the semiconductor laser and the drive circuit board in a state where the semiconductor laser is tilted around the optical axis. When the two light emitting points are tilted around the optical axis, as shown in FIG. 6, the position of the lead 58 of the semiconductor laser 39 is also tilted from the state of FIG. 1 around the optical axis according to the tilt angle θ. become.

  The tilting of the light emitting point is performed when the laser unit 30 is assembled to the optical box 36. First, the semiconductor laser 39 is press-fitted into the laser holder 40. Thereafter, a drive circuit board (not shown) for adjusting the light emission point is connected to the lead 58 of the semiconductor laser 39 (not soldered), and the rotation adjustment is performed while the light emission point emits light. When performing the rotation adjustment, the laser unit 30 is rotated around the optical axis along the V groove 36c provided in the optical box 36. When the angle of the laser unit 30 can be adjusted with a predetermined accuracy, the laser unit 30 is fixed to the optical box 36 with a spring 49, and the drive circuit board for adjusting the light emission point is removed. Thereafter, as described above, all the four leads 58 of the semiconductor laser 39 are passed through one hole 57 of the drive circuit board 37 actually mounted on the product. Then, the drive circuit board 37 is assembled to the optical box 36. Subsequently, as shown in FIG. 6, the four leads 58 of the semiconductor laser 39 are bent radially with respect to the optical axis of the semiconductor laser, and each lead is soldered to the pattern 55. Thus, the scanning optical device 3 is assembled with the two light emitting points tilted around the optical axis.

  As shown in FIG. 3, the laser units 30C and 30M are configured adjacent to each other. In this embodiment, the two semiconductor lasers 39 of the laser units 30C and 30M are driven by one drive circuit board 37. That is, as shown in FIG. 7, these two semiconductor lasers 39 are soldered to one drive circuit board 37. Therefore, when assembling, four leads 58 (total of eight) of each semiconductor laser 39 are simultaneously passed through two holes 57 provided in one drive circuit board 37, and then the leads 58 are bent. Soldering is performed.

  As described above, the drive circuit board 37 has the same number of holes 57 as the semiconductor laser 39, and all the leads of one semiconductor laser 39 are connected through one hole 57. Thus, after determining the rotation adjustment angle around the optical axis of the laser unit 30, even if the angle of the lead 58 of the semiconductor laser 39 is deviated to some extent, the lead 58 can be surely passed through the hole 57.

  Since the assembly of the scanning optical device becomes reliable and easy, in particular, a configuration in which a plurality of light emitting points are provided inside the semiconductor laser 39 or a configuration in which a number of semiconductor lasers 37 are driven by a single drive circuit board 37. In the optical apparatus, the assembly yield can be improved and the tact time can be shortened. As a result, the cost of the entire image forming apparatus can be reduced accordingly.

  Even if there are a plurality of semiconductor lasers 39, the number of holes 57 to be passed is only the number of the semiconductor lasers 39, so that it is easy to assemble all the holes 57 through the leads 58.

  In addition, since the number of holes is reduced as compared with the configuration in which holes for the number of leads 58 are provided, there is less possibility that the solder 56 hangs down to the semiconductor laser 39 through the holes 57. The risk of occurrence is reduced.

  Even when the number of leads 58 is increased, it is not necessary to increase the number of holes 57, and it is not necessary to lengthen the leads 58. For this reason, the degree of freedom in design is increased, the size of the drive circuit board 37 need not be increased unnecessarily, a compact design is possible, and the cost of the drive circuit board 37 can be reduced. In addition, the high-speed response of the semiconductor laser 39 can be kept good, and the high resolution (high dpi) or high speed of the image forming apparatus can be prevented from being hindered. Further, a general-purpose semiconductor laser 39 can be used, and the cost of the entire image forming apparatus can be reduced.

  Further, the semiconductor laser 39 can be assembled to the drive circuit board 37 without the lead 58 hitting the laser holder 40 or the drive circuit board 37. For this reason, it is possible to prevent the semiconductor laser 39 from being deteriorated due to static electricity generated by friction of the leads 58 or the like.

  Further, the hole 57 provided in the drive circuit board 37 has a rotationally symmetric shape with respect to the optical axis. As a result, the lead 58 can be passed through the hole 57 even if the rotation angle of the semiconductor laser 39 is slightly deviated. Therefore, the semiconductor laser 39 can be assembled to the drive circuit board 37 without bending the lead 58 to pass through the hole 57. Further, there is no need to forcibly adjust the semiconductor laser 39 after soldering, and the positional relationship between the light emitting point of the semiconductor laser 39 and the collimator lens 38 does not go wrong.

  Further, as described above, it is not necessary to adjust the semiconductor laser 39 by forcibly twisting it after the lead 58 is bent or soldered. For this reason, when a load is applied to the root of the lead 58, the low-melting glass is cracked, and the sealing inside the semiconductor laser is broken, and problems such as failure of the semiconductor laser 39 and the image forming apparatus can be reduced.

  Further, the lead 58 may be soldered to the pattern 55 without bending, but in this embodiment, the lead 58 of the semiconductor laser 39 is passed through one hole 57 of the drive circuit board 37 corresponding to the semiconductor laser 39 and thereafter It was set as the structure bent radially. As a result, the soldering operation is facilitated, and the problem that the solder 56 hangs down to the semiconductor laser 39 side can be further reduced.

  The pattern 55 was formed in an arc shape in the vicinity of the outer peripheral portion of the hole 57. As a result, the lead 58 can be reliably connected to the pattern 55 even if the rotation angle of the semiconductor laser 39 is slightly deviated.

  Furthermore, even when the number of light emitting points in the semiconductor laser 39 increases, the degree to which the pattern design of the drive circuit board 37 is tied to the position of the lead 58 is reduced. For this reason, the degree of freedom in design is increased, and there is no need to unnecessarily increase the substrate size.

  In the present embodiment, the scanning optical device 3 having the configuration in which the semiconductor laser 39 has two light emitting points, four leads 58, and two semiconductor lasers 39 for one drive circuit board 37 has been described. However, the present invention is not limited to such a configuration, and the same effect can be obtained even if the number of light emitting points, leads 58, drive circuit board 37, and semiconductor lasers 39 is further increased. In addition, a configuration in which there is only one semiconductor laser in the scanning optical device, such as a monochrome printer, or a configuration in which one drive circuit board is provided for each of a plurality of semiconductor lasers, that is, the number and driving of the semiconductor lasers. The present invention can also be applied to configurations having the same number of circuit boards. In the present embodiment, the drive circuit board 37 actually mounted on the product is fixed to the optical box 36 instead of the laser holder 40. However, the drive circuit board 37 is attached to the laser holder 40. You may fix to it. In particular, in the case of the above-described monochrome printer or a full-color printer having the same number of semiconductor lasers and the number of drive circuit boards, the drive circuit board that is actually mounted on the product without using the drive circuit board for adjusting the light emission point described above. You may adjust rotation in the state which attached 37 to the laser holder 40. FIG. In this case, the light source device has not only a semiconductor laser but also a drive circuit board.

[Second Embodiment]
Next, a second embodiment of the light source device and the scanning optical device according to the present invention will be described with reference to the drawings. About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 8 is a perspective view of the semiconductor laser according to the present embodiment. The scanning optical device 3 according to the present embodiment uses a semiconductor laser 139 shown in FIG. 8 instead of the semiconductor laser 39 of the first embodiment.

  The semiconductor laser 139 has a configuration in which a metal lead frame 59 is wrapped with a resin package 61 (so-called frame package). For this reason, the semiconductor laser 139 can be manufactured in the same way as other ICs, and has a feature that is very advantageous in terms of cost.

  The semiconductor laser 139 includes a laser chip 50 having a light emitting point and a photodiode 54. The laser chip 50 is die-bonded to the submount 52, and the photodiode 54 is configured integrally with the submount 52. On the side opposite to the die-bonded side of the laser chip 50 and the photodiode 54, an Au wire 62 or the like is wire-bonded to the lead 158 using an ultrasonic wave or the like, and is connected to the corresponding lead 158. ing.

  The leads 158 of the semiconductor laser 139 have a rectangular cross section, and all the leads 158 are aligned on a straight line. For this reason, the bending direction of the lead 158 is restricted to a predetermined direction.

  Since the resin package 61 is very poor in heat dissipation, a part of the metal lead frame 59 jumps out of the resin package 61 to form a heat sink 60.

  As shown in FIG. 9, the semiconductor laser 139 is fixed to the laser holder 40 using a method such as press-fitting, screwing, or bonding, and the collimator lens 38 is bonded and fixed to the collimator barrel 41. Then, after adjusting the collimator barrel 41 to the laser holder 40 so as to obtain the optimum collimated light in the optical axis direction and the three-dimensional directions in the plane XY direction perpendicular to the optical axis, the adhesive is fixed. By unitization (laser unit 30). The laser unit 30 is assembled to the optical box 36 using screws 35, springs 49, and the like. The semiconductor laser 139 is electrically connected to the laser drive circuit board 37 by soldering or the like. The drive circuit board 37 supplies current to the semiconductor laser 139 and controls ON / OFF of light emission of the semiconductor laser 139. The drive circuit board 37 is integrally fixed to the optical box 36.

  As shown in FIG. 10, one semiconductor laser 139 has three leads 158. The drive circuit board 37 has the same number of holes 57 as the semiconductor laser 39. When combining the semiconductor laser 139 and the drive circuit board 37, first, all three leads 158 are passed through one hole 57 of the laser drive circuit board 37, and then the leads 158 are bent. The laser driving circuit board 37 is provided with a pattern 55 along the outer periphery of the hole 57. The pattern 55 is formed in an arc shape that is divided into three in accordance with the three leads 158.

  The leading end side of the lead 158 after bending is soldered to the arc-shaped portion of the pattern 55 with solder 56. The pattern 55 is connected to a driver IC (not shown) or a corresponding drive circuit (not shown). With this configuration, ON / OFF of light emission of the semiconductor laser 139 is controlled from the driver IC or the like via the pattern 55.

  As described above, as in the so-called frame package type semiconductor laser 139, the leads 158 are arranged in a straight line, and the cross-sectional shape of the leads 158 is rectangular so that the bending direction of the leads 158 is regulated. Even a general-purpose semiconductor laser can be reliably assembled and connected to the drive circuit board 37, and the cost of the entire image forming apparatus can be reduced. Moreover, the same effect as said 1st embodiment can be acquired.

[Third embodiment]
Next, a third embodiment of the light source device and the scanning optical device according to the present invention will be described with reference to the drawings. Portions that are the same as those described in the first embodiment and the second embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 15 is a diagram for explaining the state of connection between the semiconductor laser and the drive substrate according to this embodiment. The scanning optical device 3 according to the present embodiment is different in shape from the holes that are perforated in the first embodiment and the second embodiment. As shown in FIG. 15, the perforated hole has a shape divided into two parts, a D part and an E part.

  In other words, the rib shape is inserted between the D part and the E part and divided so that the rigidity of the laser drive circuit board 37 can be kept high, and a circuit pattern can be formed on the rib shaped part. Good.

  The hole has a form in which the round hole is divided into two parts, the D part and the E part. However, as described in the first embodiment, the hole part is not limited to the round hole, and has at least a rotationally symmetric shape such as a regular polygon. Any shape that divides may be used.

  In FIG. 15, the semiconductor laser 39 is provided with four leads 58, and two leads 58 are passed through each of the divided holes, the D part and the E part, but the number of leads 58 of the semiconductor laser 39 is four or more. The hole may not be divided into two parts. That is, the number of holes may be larger than the number of semiconductor lasers 39 and smaller than the number of leads 58.

  As a result, while adding the effect of maintaining the rigidity around the hole portion of the laser drive circuit board 37, the hole portion has a margin even if the rotation angle of the semiconductor laser 39 is slightly deviated as in the first embodiment. As a result, it is possible to obtain an effect such that the lead 58 can be reliably connected.

It is explanatory drawing of the connection state of the semiconductor laser which concerns on 1st embodiment, and a drive circuit board | substrate. 1 is a configuration diagram of an image forming apparatus. It is a block diagram of the scanning optical apparatus provided with one light source device. It is a block diagram around a light source device. It is a block diagram of a semiconductor laser. It is explanatory drawing of the connection state of a semiconductor laser and a drive circuit board | substrate in the state which inclined the semiconductor laser around the optical axis. It is a block diagram of the scanning optical apparatus provided with the several light source device. It is a perspective view of the semiconductor laser which concerns on 2nd embodiment. It is a block diagram of the scanning optical apparatus provided with one light source device. It is explanatory drawing of the connection state of a semiconductor laser and a drive circuit board | substrate. It is explanatory drawing of the connection state of the conventional semiconductor laser and a drive circuit board | substrate. It is explanatory drawing of the connection state of the conventional semiconductor laser and a drive circuit board | substrate. It is explanatory drawing of the connection state of the conventional semiconductor laser and a drive circuit board | substrate. It is explanatory drawing of the connection state of the conventional semiconductor laser and a drive circuit board | substrate. It is explanatory drawing of the connection state of the semiconductor laser which concerns on 3rd embodiment, and a drive circuit board | substrate.

Explanation of symbols

A ... surface, B ... tip side, C, D ... tapered surface, L ... laser beam, 3 ... scanning optical device, 30 ... laser unit, 31 ... polygon mirror, 32 ... scanning lens, 33 ... folding mirror, 34 ... development 35 ... Screw, 36 ... Optical box, 36c ... Groove, 37 ... Drive circuit board, 38 ... Collimator lens, 39, 139 ... Semiconductor laser, 40 ... Laser holder, 41 ... Collimator barrel, 42 ... Drive roller, 43 ... Fixer, 44 ... transfer belt, 45 ... transfer material, 46 ... photosensitive drum (corresponding to image carrier), 47 ... primary charger, 48 ... discharge roller, 50 ... laser chip (corresponding to light emitting point), 51 ... Stem, 52 ... Submount, 53 ... Window cap, 54 ... Photodiode (corresponding to light emitting point), 55 ... Pattern, 56 ... Solder, 57 ... Hole, 58, 158 ... Lead, 59 ... Lead frame, 60 ... Heat dissipation Board, 61 ... resin package, 62 ... Au wire

Claims (12)

In a light source device having a semiconductor laser that emits laser light, and a drive circuit board that is connected to a plurality of terminals of the semiconductor laser and drives the semiconductor laser,
The drive circuit board is provided with at least one hole through which a terminal of the semiconductor laser passes, and two or more of the terminals pass through one hole. The said hole provided in the said board | substrate with respect to one said semiconductor laser is one, All the terminals of the said semiconductor laser are passing through this one hole, The said one is characterized by the above-mentioned. Light source device. The light source device according to claim 2, wherein the hole has a rotationally symmetric shape with respect to an optical axis of the semiconductor laser. 2. The light source device according to claim 1, wherein a plurality of holes are provided in the substrate for one semiconductor laser, and a plurality of the terminals pass through each of the holes. The light source device according to claim 4, wherein the plurality of holes are obtained by dividing a rotationally symmetric shape with respect to an optical axis of the semiconductor laser. The light source device according to claim 1, wherein the plurality of terminals passing through the holes are bent radially with respect to an optical axis of the semiconductor laser. A scanning optical apparatus comprising: a semiconductor laser that emits laser light; a drive circuit substrate that is connected to a plurality of terminals of the semiconductor laser and drives the semiconductor laser; and a scanning optical system that deflects and scans the laser light emitted from the semiconductor laser In
2. A scanning optical device according to claim 1, wherein at least one hole through which a terminal of the semiconductor laser passes is provided in the drive circuit board, and two or more of the terminals pass through one hole. The number of the holes provided in the substrate for one semiconductor laser is one, and all the terminals of the semiconductor laser pass through the one hole. Scanning optical device. 9. The scanning optical device according to claim 8, wherein the hole has a rotationally symmetric shape with respect to the optical axis of the semiconductor laser. The scanning optical device according to claim 7, wherein a plurality of the holes provided in the substrate with respect to one semiconductor laser are provided, and a plurality of the terminals pass through each of the holes. . The scanning optical apparatus according to claim 10, wherein the plurality of holes are obtained by dividing a rotationally symmetric shape with respect to an optical axis of the semiconductor laser. The scanning optical device according to claim 7, wherein the plurality of terminals passing through the holes are bent radially with respect to an optical axis of the semiconductor laser.

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