JP2007034208A - Scanning optical apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scanning optical apparatus in which high quality picture information without color shift is recorded by suppressing the shift of a scanning line caused by the scanning optical apparatus and to provide an image forming apparatus using the scanning optical apparatus. <P>SOLUTION: The scanning optical apparatus, in which luminous fluxes emitted from light source means 150a and 150b are deflected with a deflection means housed in a case 111 to scan a photoreceptor drum, is characterized in that a base 144 is provided for fixing the light source means 150a and 150b with an adhesive 160 between V-shaped grooves 131 and 132 which are provided with a predetermined space in the emitting direction of the luminous fluxes for positioning the light source means 150a and 150b by abutting them to the case 111. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scanning optical device that deflects and scans a light beam and irradiates a scanned object with light, and an image forming apparatus that includes the scanning optical device.

  Conventionally, in a scanning optical device used for a printer, a digital copying machine or the like, a light beam that is light-modulated from a light source according to an image signal and emitted is periodically deflected and scanned by an optical deflector such as a rotating polygon mirror, for example. This is focused in a spot shape on the imaging surface on the photosensitive drum. The spot on the imaging surface forms an electrostatic latent image in accordance with main scanning by the deflector and sub-scanning by rotation of the photosensitive drum, and image recording is performed.

  FIG. 6 shows a scanning optical device 100 according to a conventional example. A divergent light beam emitted from a light source 11 is made into a substantially parallel light beam by a collimator lens 12, and a light amount of the light beam is adjusted by a diaphragm 13 and refracted only in the sub-scanning direction. It enters a cylindrical lens 14 having a force.

  The parallel light beam incident on the cylindrical lens 14 is emitted as a light beam that converges only in the sub-scanning section in the state of a substantially parallel light beam in the main scanning section, and is formed as a line image on the reflecting surface of the rotary polygon mirror 15. To do.

  The light beam deflected and scanned by the rotation of the rotary polygon mirror 15 forms an image on the imaging surface of the photosensitive drum 20 through an fθ lens 16 which is an imaging optical element having fθ characteristics. The optical component is housed in the optical case 17 and installed in the image forming apparatus.

  A point image (spot) imaged on the imaging surface is scanned on the photosensitive drum 20 in the direction of arrow B by rotating the rotary polygon mirror 15 in the direction of arrow A. Image recording is performed on the photosensitive drum 20 with such main scanning and sub-scanning by rotating the photosensitive drum 20 around its rotation axis.

  Here, the light source means including the light source 11 and the collimator lens 12 is adjusted to the optical case 17 with high positional accuracy, and is fastened and fixed by, for example, screws (Patent Document 1). In addition to the screws, there are a method of pressing and fixing the light source means to the positioning portion of the optical case 17 with an elastic member (Patent Document 2), or a method of fixing using an ultraviolet curable adhesive. Such a fixing method is effective when the design space around the light source means is small.

Japanese Patent Laid-Open No. 10-319336 Japanese Patent Laid-Open No. 05-011202

  The method of adjusting the light source means described above to the scanning optical device and fastening the screw may cause the adjustment value to be distorted due to an impact caused by the fastening of the screw. For example, as shown in FIG. 7, when the light source means 10 is fitted to the fitting portion 19 provided in the optical case 17 and fastened with screws 18a and 18b, the light source means 10 is fastened by fastening the screws 18a and 18b. Accompanying may occur. And when the fall of the arrow C direction generate | occur | produces by interference with a fitting part, the fall of an optical axis will generate | occur | produce and a spot will enlarge.

  With respect to this problem, as shown in Patent Document 2, the light source means can be fixed with high accuracy by establishing the relationship between the position where the elastic member is not shielded from ultraviolet irradiation and the application position of the adhesive.

  However, in the configuration of Patent Document 2, the adhesion point is limited to one place by using the elastic member and the adhesive together. For this reason, a force that rotates around the optical axis is generated due to the curing shrinkage of the adhesive, and for example, the adjustment value may be distorted in the light source means that rotates and adjusts the scanning line pitch of the sub-scanning around the optical axis.

  Further, even if the application amount of the ultraviolet curable adhesive is strictly controlled, the adhesive wraps around the light source means, the ultraviolet rays do not hit, and an uncured portion is generated. This uncured portion may move the light source means due to environmental fluctuations.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a scanning optical apparatus capable of recording high-quality image information without color misregistration while suppressing scanning line misregistration by the scanning optical apparatus. An image forming apparatus using the same is provided.

  A representative means in the present invention for solving the above-mentioned problems is a scanning optical device that performs scanning by deflecting the light beam emitted from the light source means by the deflecting means housed in the housing and scanning the object to be scanned. In order to position the light source means against the housing, the light source means has a positioning portion provided at a predetermined interval in the light emission direction, and the light source means is bonded and fixed between the positioning portions with an adhesive. It has the fixing member for, It is characterized by the above-mentioned.

  In the present invention, in order to position the light source means against the casing, the light source means is adhered and fixed with an adhesive between the positioning portions provided at predetermined intervals in the light emission direction, so that the distance for positioning is determined. Can be lengthened. For this reason, the light source means can be stably fixed and can be fixed at the center of gravity of the light source means.

  Next, a scanning optical apparatus according to an embodiment of the present invention will be described with reference to the drawings together with an image forming apparatus using the scanning optical apparatus.

{Image forming device}
First, the overall configuration of the image forming apparatus according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional explanatory diagram of the image forming apparatus of the present embodiment.

  In FIG. 1, reference numeral 151 denotes a scanning optical device having a configuration to be described later, and reference numerals 1Y, 1M, 1C, and 1Bk denote photosensitive drums that are arranged at equal pitches and that serve as image bearing members as predetermined surfaces.

  In the present embodiment, light beams (laser beams) LY, LM, LC, and LBk that are light-modulated based on image information are emitted from the scanning optical device 151, and the corresponding photosensitive drums 1Y, 1M, 1C, and An electrostatic latent image is formed by irradiating the 1 Bk surface.

  The latent images are formed on the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk that are uniformly charged by the primary chargers 2Y, 2M, 2C, and 2Bk, respectively. The toner images of yellow, magenta, cyan, and black are visualized by the developing devices 4Y, 4M, 4C, and 4Bk, respectively, and are superimposed on the intermediate transfer belt 8 by the transfer rollers 5Y, 5M, 5C, and 5Bk. Transcribed.

  Thereafter, residual toner remaining on the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk is removed by the cleaners 6Y, 6M, 6C, and 6Bk, and the primary chargers 2Y, 2Y, and 2Y are formed again to form the next color image. It is uniformly charged by 2M, 2C, 2Bk.

  The transfer material P is stacked on the feed tray 21, and is fed one by one by the feed roller 22 in order, and is sent out onto the conveyor belt 7.

  While being transported on the transport belt 7, the color toner image formed on the surface of the intermediate transfer belt 8 is transferred onto the transfer material P to form a color image.

  The color image formed on the transfer material P is heat-fixed by the fixing device 25, and is then conveyed by the discharge roller 26 and outputted outside the apparatus.

{Scanning optical device}
Next, the scanning optical device 151 that optically scans the photosensitive drums 1Y, 1M, 1C, and 1Bk will be described. FIG. 2 is a schematic front view for explaining the configuration of the scanning optical apparatus.

  In the scanning optical device 151 of the present embodiment, as shown in FIG. 2, two optical scanning units 200a and 200b having the same configuration are arranged in parallel in an optical casing 111 which is an optical case. Each light scanning means 200a (200b) deflects and scans the light beams from the two light source means 150a and 150b (150c and 150d) by the deflecting means 109 (110). Then, the light beam is folded back by the optical member group arranged substantially symmetrically with respect to the deflecting means 109 (110), and optical scanning is performed on the photosensitive drum as the two scanned objects. By arranging two sets of this optical scanning means in parallel, each of the four photosensitive drums performs optical scanning according to the image signal.

  Here, as shown in FIGS. 1 and 2, the optical member group includes the first scanning lenses 103a and 103b (103c and 103d), the folding mirrors 104a and 104b (104c and 104d), and the second scanning lens. 105a, 105b (105c, 105d). Then, the light flux is folded back by the folding mirrors 104a and 104b (104c and 104d), and optical scanning is performed on the photosensitive drum, which is two scanned bodies.

  That is, the light beam emitted from the light source is incident on different surfaces of the rotary polygon mirror 102 (108) constituting the deflecting means, and is scanned in different directions. The light beams scanned by the rotary polygon mirror 102 (108) pass through the first scanning lenses 103a and 103b (103c and 103d), respectively. The direction is changed by folding mirrors 104a and 104b (104c and 104d) which are the same pitch as the photosensitive drum pitch and are arranged at an angle of about 45 ° with respect to the incident light beam. Further, the luminous flux passes through the second scanning lenses 105a and 105b (105c and 105d), and the scanning light can be imaged on the four photosensitive drums.

  In the scanning optical device 151 of the present embodiment, as shown in FIG. 1, the light beam folded by the folding mirror 104a is applied to the photosensitive drum 1Bk that forms a black image, and the beam folded by the folding mirror 104b is a cyan image. The photosensitive drum 1 </ b> C that forms the image is irradiated. Similarly, the folding mirrors 104c and 104d irradiate the photosensitive drums 1M and 1Y for forming a magenta image and a yellow image, respectively.

  The scanning optical device 151 includes deflecting units 109 and 110 having rotary polygon mirrors 102 and 108, respectively, on the same plane of one casing 111. All of the scanning optical members such as the other folding mirrors 104a, 104b, 104c, and 104d and the scanning lenses 103a, 103b, 103c, 103d, 105a, 105b, 105c, and 105d are placed in a casing 111 formed of resin or the like. I have.

{Fixing the light source means}
Next, a fixed configuration of the light source means 150a, 150b, 150c, and 150d in the scanning optical device 151 will be described. Since the optical scanning units 200a and 200b have the same configuration, the fixed configuration of the light source unit will be described with respect to the light source units 150a and 150b in the optical scanning unit 200a on one side.

  3 is a perspective explanatory view of the light source means, FIG. 4 shows a fixing structure of the optical means, (a) is a top view, and (b) is an AA cross-sectional explanatory view of (a). is there.

  As shown in FIG. 3, the light source means 150a and 150b have cylindrical holders 141a and 141b as holding members, and semiconductor lasers 101a and 101b as light sources are attached to one end of the holders 141a and 141b by press fitting or the like. ing. Then, collimator barrels 140a and 140b are attached to the other ends of the holders 141a and 141b. The collimator barrels 140a and 140b are bonded and fixed to collimator lenses that convert the laser light emitted from the semiconductor lasers 101a and 101b into parallel light or a prescribed convergent light beam. Then, light beams (beams) emitted from the semiconductor lasers 101a and 101b serving as light sources are incident on different surfaces of the rotary polygon mirror 102 that constitutes the deflecting means 109 described above, and are scanned in different directions.

  The casing 111 is provided with a positioning portion provided at a predetermined interval in the light emission direction in order to abut the light source means 150a and 150b for positioning. In the present embodiment, as shown in FIG. 3, V-shaped grooves 131 and 132 serving as positioning portions are provided in the casing 111 at a predetermined interval. As shown in FIG. 4B, the V-shaped grooves 131 and 132 have a shape wider than the diameter of the cylindrical holders 141a and 141b and narrower than the diameter. Therefore, by abutting the holders 141a and 141b against the V-shaped grooves 131 and 132, the movement of the holders 141a and 141b in the direction orthogonal to the emitted light beam is restricted, and the positioning in the direction is performed.

  Further, the positioning in the light emission direction is performed by abutting the flange portions 145a and 145b provided on the holders 141a and 141b against the abutting portion 133 provided on the optical casing 111.

  When the light source means 150a and 150b are assembled to the optical casing 111, as shown in FIG. 3, the holders 141a and 141b are securely attached to the inner surfaces of the V-shaped grooves 131 and 132 by pressing members 142a and 142b such as tools. The pressure is applied at a pressure of about 70 gf to 200 gf so as to hit the surface. At this time, for example, when the semiconductor lasers 101a and 101b have a plurality of light sources, the light source means 150a and 150b are rotated in the directions of arrows a1 and a2 to adjust the scanning line interval in the sub-scanning direction.

  In this embodiment, the light source means 150a and 150b are fixed to the casing 111 by bonding with an adhesive. For this purpose, a base 144 as a fixing member for bonding is fixed to the casing 111 between the V-shaped grooves 131 and 132. In this embodiment, an ultraviolet curable adhesive 160 is used as the adhesive, which is applied and adhered between the left and right side surfaces of the respective holders 141a and 141b and the base 144.

  As shown in the top view of FIG. 4A, the adhesive 160 is applied by an adhesive applicator 152 from above, for example. At this time, the application position is between the V-shaped grooves 131 and 132 provided at a predetermined interval in the direction of the outgoing light beam, and is applied at substantially the same position as the V-shaped grooves 131 and 132.

  Thereby, the shrinkage direction b generated by the curing shrinkage of the adhesive 160, which is indicated by the arrow in FIG. 4B, is the direction in which the holders 141a and 141b abut against the V-shaped grooves 131 and 132. For this reason, the light source means 150a, 150b can be assembled without being lifted from the V-shaped grooves 131, 132 due to curing shrinkage of the adhesive 160.

  After applying the adhesive 160 as described above, the adhesive 160 is solidified by irradiating the application part with ultraviolet rays by an ultraviolet irradiation device.

  FIG. 5 is an explanatory diagram of the light source means 150a and 150b and the ultraviolet irradiation device. The optical casing 111 is provided with an opening 170 that penetrates between the V-shaped grooves 131 and 132 in the vertical direction indicated by the arrow c. For this reason, the applied adhesive 160 is exposed from the vertical direction.

  Then, the adhesive 160 is irradiated so as to be sandwiched between the ultraviolet irradiation devices 154a and 154b from the vertical direction (arrow c direction). Thereby, for example, when the adhesive 160 wraps around the Ub portion of FIG. 5, it can be cured by the ultraviolet irradiation device 154b.

  When an uncured portion of the adhesive 160 is generated, curing of the uncured portion is promoted by the environment after adjustment of the scanning optical device 151, and the position of the light source means 150a and 150b is changed, so that the adjusted scanning line is displayed. May fluctuate.

  However, in this embodiment, as described above, by reducing the influence due to the curing shrinkage of the adhesive 160 that occurs when the light source means 150a and 150b are assembled to the optical casing 111 with the adhesive 160, the variation in the assembling is reduced. It becomes possible to reduce. Further, it is possible to install the ultraviolet irradiation devices 154a and 154b in an arrangement in consideration of the wraparound of the adhesive 160, and by eliminating uncured portions of the adhesive 160, it is possible to suppress fluctuations in the scanning line after adjustment. .

  In the scanning optical device 151 of the present embodiment, as described above, the V-shaped grooves 131 and 132 are provided at a predetermined interval in the light emission direction, and the light source means 150a and 150b are positioned by the grooves, and Bonded and fixed. For this reason, it can fix at the gravity center position of the light source means 150a and 150b, and can lengthen the distance for positioning. As a result, the light source means 150a and 150b can be stably fixed.

  Further, since the direction in which the light source means 150a and 150b abut against the V-shaped grooves 131 and 132 and the shrinkage direction by the adhesive 160 are substantially the same direction, the force generated by the curing and shrinkage of the adhesive is the positioning portion. It is possible to reduce the fluctuation due to before and after bonding.

  In addition, an opening 170 is provided in the casing 111 between the V-shaped grooves 131 and 132 in a direction substantially orthogonal to the light beam emission direction and in a direction substantially parallel to the pedestal 144.

  As a result, the adhesive 160 turned to the back side of the light source means 150a and 150b is also reliably cured, and the uncured portion can be eliminated.

1 is a schematic cross-sectional explanatory diagram of an image forming apparatus. It is a schematic front explanatory drawing for demonstrating the structure of a scanning optical apparatus. It is perspective explanatory drawing of a light source means. FIGS. 2A and 2B show a fixing configuration of the optical means, in which FIG. 1A is a top view and FIG. It is explanatory drawing of a light source means and an ultraviolet irradiation device. It is a perspective explanatory drawing of the scanning optical apparatus which concerns on a prior art. It is explanatory drawing of the fixing method of the light source means which concerns on a prior art.

Explanation of symbols

P: transfer material 1Y, 1M, 1C, 1Bk ... photosensitive drum
101a, 101b ... semiconductor laser
102,108 ... rotating polygon mirror
103a, 103b, 103c, 103d ... scanning lens
104a, 104b, 104c, 104d ... Mirror
105a, 105b, 105c, 105d ... scanning lens
109, 110 ... deflection means
111… Case
131,132 ... V-shaped groove
133… Bump
140a, 140b ... Collimator tube
141a, 141b ... Holder
142a, 142b ... pressure member
144… pedestal
145a, 145b ... Flange
150a, 150b, 150a, 150b ... Light source means
151… Scanning optical device
152… Adhesive application device
153… Shrink direction
154a, 154b ... UV irradiation device
160… Adhesive
170… opening
200a, 200b ... Optical scanning means

Claims (7)

In a scanning optical device that scans a beam to be scanned by deflecting and scanning a light beam emitted from a light source unit by a deflection unit housed in a housing,
In order to position the light source means against the housing, the positioning unit is provided at a predetermined interval in the emission direction of the light beam,
A scanning optical apparatus comprising a fixing member for bonding and fixing the light source means with an adhesive between the positioning portions. 2. The scanning optical apparatus according to claim 1, wherein the positioning unit positions the light source means in the light beam emission direction and a direction orthogonal thereto. 3. The scanning optical apparatus according to claim 2, wherein the positioning in the direction orthogonal to the light beam emitting direction is performed by abutting the light source means on a V-shaped groove provided in the casing. 3. The scanning optical apparatus according to claim 2, wherein positioning in the light beam emission direction is performed by abutting a flange portion provided in a light source means against the casing. 5. The scanning optical apparatus according to claim 1, wherein a direction in which the light source unit is brought into contact with the positioning portion and a contraction direction by the adhesive are substantially the same. The scanning optical device according to claim 1, wherein the housing includes an opening for exposing the adhesive between the positioning portions. In an image forming apparatus for forming a latent image by optically scanning an image carrier and developing the latent image to form an image,
An image forming apparatus comprising the scanning optical device according to claim 1 as a scanning optical device that optically scans the image carrier.

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