JP3946878B2 - Optical scanning device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical scanning device, and more particularly to a structure for attaching and detaching a synchronization detection sensor for starting writing provided in the optical scanning device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an optical scanning device provided in an image forming apparatus such as a copying machine, a facsimile, or a printer is known. The optical scanning device has an optical deflecting unit for deflecting a laser beam to scan the photosensitive member, a synchronization detection sensor for starting writing by the laser beam, and the like. In a conventional optical scanning device, a support plate that supports a synchronization detection sensor is attached to a non-moving member such as a casing that houses an optical deflecting means by screwing.
[0003]
[Problems to be solved by the invention]
However, when removing the synchronization detection sensor when the synchronization detection sensor fails, or when installing a new synchronization detection sensor, the support plate is located inside the image forming apparatus. The work of was very difficult. In order to ensure workability, it is possible to open a hole through which the screwdriver passes in another mechanism in the image forming apparatus, but this leads to high cost of the apparatus, and the removed screw is also in the image forming apparatus. There is a problem that it may fall.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide an optical scanning device that can easily attach and remove a synchronization detection sensor.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is an optical scanning device comprising a light deflecting means for deflecting a laser beam to scan on a photosensitive member, and a synchronous detection sensor for starting writing by the laser beam. with a at, a support for supporting the synchronous detection sensor, and positioning means for positioning the support stationary member, toward the stationary member the support positioned in the stationary member by said positioning means and a leaf spring which is screwed to the stationary member for energizing said stationary member in the casing and substantially integrally der Ru optical scanning device which accommodates the light deflecting means, the plate spring, a first It has an L-shaped cross section consisting of a bottom part having a bent part and a pressing part having a second bent part, wherein the first bent part is used as the stationary member and the second bent part is used as the support. Each engaged and on A temporary fixing position you urging the support towards said stationary member screws in a state of relaxed, the base section in the temporarily fixed position toward the stationary member the support by tightening with the screw It has a fixed position which is urged by the pressing portion and fixes the synchronous detection sensor at a position where it can be operated.
[0006]
According to a second aspect of the present invention, in the optical scanning device according to the first aspect , the synchronization detection sensor, the support for supporting the synchronization detection sensor, and the positioning means for positioning the support on the stationary member. And the leaf spring fixed to the stationary member for urging the support body positioned on the stationary member by the positioning means toward the stationary member is provided outside the closed space of the optical scanning device. It is characterized by being.
[0007]
According to a third aspect of the present invention, in the optical scanning device according to the first or second aspect, the positioning means includes a protrusion provided on the support and the immovable member, and an engagement engaging with the protrusion. It has a hole .
[0008]
According to a fourth aspect of the present invention, in the optical scanning device according to any one of the first to third aspects, the leaf spring has a convex portion that presses the support .
[0009]
According to a fifth aspect of the present invention, in the optical scanning device according to the fourth aspect , the convex portion is provided in the vicinity of the positioning means .
[0010]
According to a sixth aspect of the present invention, in the optical scanning device according to any one of the first to fifth aspects, the screwing direction of the screw urges the support toward the stationary member by the leaf spring. The direction is different from the direction to be performed.
[0013]
【Example】
As shown in FIG. 1 or FIG. 2, the optical scanning device 1 rotates a polygon mirror 2 that is a rotating polygon mirror as a light deflecting means for deflecting a laser beam and scanning the photosensitive member, and the polygon mirror 2. A scanner motor 3 for driving, a laser diode 4 for emitting a laser beam, a first mirror 5 for reflecting the laser beam emitted by the laser diode 4 toward the polygon mirror 2, a laser diode 4 and a first mirror 5, A second lens 9 that reflects the laser beam deflected by the polygon mirror 2 toward a photosensitive member 8 as an electrostatic latent image carrier, a first mirror 5 and a second mirror 5. The fθ lens 7 disposed between the mirror 9 and the laser beam before being incident on the second mirror 9 after being deflected by the polygon mirror 2 is detected. And a synchronization detection sensor 10 for starting writing by Zabimu. In FIG. 2, reference numeral 27 denotes a cylindrical lens.
[0014]
The synchronization detection sensor 10 is fixed and supported on a support plate 11 as a support. As shown in FIG. 3, the support plate 11 includes protrusions 13a and 13b provided on the abutting portions 26a and 26b provided on the casing 12 accommodating the polygon mirror 2 and the like, and the protrusions 13a and 13b. The casing 12 is positioned by positioning means having engaging holes 14a and 14b provided in the support plate 11 engaged with the casing 12.
[0015]
The leaf spring 15 biases the support plate 11 positioned on the casing 12 by the positioning means toward the casing 12, and the shape thereof is a cross section L in the direction of biasing the support plate 11 toward the casing 12. A bottom portion 15a as a bottom side screwed to the casing 12 by a screw 16; and a pressing portion 15b having embosses 17a and 17b as projections standing from the bottom portion 15a and pressing the support plate 11; Have
[0016]
The embosses 17a and 17b are provided in the vicinity of the engagement holes 14a and 14b, respectively. The synchronization detection sensor 10 is located on a straight line connecting the engagement holes 14a and 14b. The engagement hole 14b has a notch shape, and ensures the engagement of the embosses 17a and 17b with the engagement holes 14a and 14b. The bottom portion 15a and the pressing portion 15b have acute angles, and have bent portions 18 and 19 that are bent in directions facing each other.
[0017]
The pressing portion 15b has long holes 20a and 20b that engage with the protrusions 13a and 13b on a straight line connecting the embosses 17a and 17b in the vicinity of the embosses 17a and 17b. The tip of the embossing 17a and the hole 20a side of the pressing part 15b is cut out. The bottom portion 15 a is screwed to the casing 12 with a screw 16 from a direction different from the direction in which the pressing portion 15 b presses the support plate 11 toward the casing 12.
[0018]
The casing 12 surrounds and supports the window 21 provided at a position that does not prevent the laser beam deflected by the polygon mirror 2 from entering the positioned synchronous detection sensor 10, the window 21, and the embosses 13a and 13b. And an edge 22 having a size that allows the plate 11 to enter. The edge portion 22 of the portion to which the bottom portion 15a is screwed forms a step portion 23 by this and the casing 12 body.
[0019]
The step portion 23 engages with the bent portion 18, and in this state, the bent portion 19 engages with the side edge of the support plate 11 positioned on the casing 12 by the positioning means. . The leaf spring 15 is fixed to the casing 12 with a screw, and the support plate 16 is urged and fixed toward the casing 12 in a state where the screw 16 is loosened. 5 has a fixed position shown in FIG. 5 in which the support plate 11 is urged toward the casing 12 by tightening the screw 16 to fix the synchronization detection sensor 10 to an operable position.
[0020]
The angle formed between the bottom portion 15a and the pressing portion 15b is set so that the leaf spring 15 is urged in a direction in which the support plate 11 and the step portion 23 are sandwiched at the temporarily fixed position. Further, the leaf spring 15 is in a state in which the bottom portion 15a is lifted from the casing at the temporarily fixed position. However, when the screw 16 is tightened to occupy the fixed position, at least the screwing portion is attached to the casing 12. The other parts abut against the casing 12 or are slightly separated from each other.
[0021]
Since the present embodiment is configured as described above, the laser beam emitted from the laser diode 4 is incident on the polygon mirror 2 rotating in the counterclockwise direction in FIG. 1 through the cylindrical lens and the first mirror 5. 1 is deflected so as to be swung from the right side to the left side in FIG. The deflected laser beam passes through the fθ lens 7, is reflected by the second mirror 9 to the back side of the paper surface in FIG. 1, and scans the photoconductor 8 through the cylindrical lens 27.
[0022]
At this time, the synchronization detection sensor 10 disposed on the side where the laser beam is incident on the second mirror detects the deflection timing of the laser beam by the polygon mirror 2, and based on this, the timing of the start of writing on the photosensitive member 8 is detected. And the light emission of the laser diode 4 is controlled based on the data of the formed image existing on the image forming apparatus main body side, and an electrostatic latent image for forming a desired image is accurately formed on the photoreceptor 8. The
[0023]
When the synchronization detection sensor 10 deteriorates with time and needs to be replaced, the tightened spring 16 is loosened, the leaf spring 15 is displaced from the fixed position to the temporary fixed position, and the screw 16 is removed. Even if the screw 16 is removed, the leaf spring 15 is set so that the angle formed between the bottom portion 15a and the pressing portion 15b is biased in a direction to sandwich the support plate 11 and the step portion 23. The bent portions 18 and 19 engage with the step portion 23 and the support plate 11 and do not fall by their own weight. Since the support plate 11 is exposed when the operator removes the leaf spring 15 following the screw 16, the synchronization detection sensor 10 is removed together with the support plate 11.
[0024]
When attaching the synchronization detection sensor 10, the new synchronization detection sensor 10 is fixed to the support plate 11, the protrusions 13a and 13b are engaged with the engagement holes 14a and 14b, and the support plate 11 is abutted against the abutment portion 26a. The protrusions 13a and 13b protruding from the engagement holes 14a and 14b are inserted into the holes 20a and 20b, and the bent portions 18 and 19 are engaged with the step portion 23 and the support plate 11, respectively. In a state where the leaf spring 15 occupies the temporarily fixed position, the embosses 17a and 17b urge the support plate toward the casing 12 with a predetermined force.
[0025]
When the plate spring 15 is tightened with the screw 16 so as to occupy the fixed position, the bottom portion 15 contacts or approaches the casing 12, and the pressing portion 15b directs the support plate 11 toward the casing 12 via the embosses 17a and 17b. The synchronous detection sensor 10 is accurately positioned at an operable position. When the leaf spring 15 occupies a fixed position, the embosses 17a and 17b are positioned on a straight line connecting the engagement holes 14a and 14b, and the support plate 11 is sandwiched between the abutting portions 26a and 26b. ing.
[0026]
As the screw 16 is tightened, the bent portion 19 is separated from the support plate 11 and slightly separated from the inner wall of the edge portion 19, so that the edge portion 19 is covered with the leaf spring 15, and the casing 12, the plate Intrusion of dust or the like into the space formed by the spring 15 is prevented, and the operating environment of the synchronization detection sensor 10 is kept good. Since the holes 20a and 20b are long holes, the protrusions 13a and 13b slide in the holes 20a and 20b when the leaf spring 15 is displaced from the temporarily fixed position to the fixed position.
[0027]
As described above, in this embodiment, the stationary member is substantially integrated with the casing that houses the light deflection means. However, the stationary member that positions the support and the stationary member that fixes the leaf spring are substantially the same. Further, it may be integral with the casing 12 or may be another immovable member on the image forming apparatus main body side. If the lengths of the protrusions 13a and 13b are shortened, the holes 20a and 20b provided in the leaf spring 15 become unnecessary.
[0028]
The protrusion may be provided on the support plate side and the engagement hole may be provided on the stationary member side, or the support plate and the stationary member may be provided with a protrusion and an engagement hole that engage with each other. Only one emboss may be provided, or three or more may be provided. The embossing position may be provided regardless of the position of the engagement hole. The synchronization detection sensor 10 may not be located on a straight line connecting the engagement holes 14a and 14b. Even if the leaf spring is not L-shaped in cross section, the leaf spring may have a warped shape as long as it has sufficient elastic force.
[0029]
As shown in FIG. 1, if the laser beam deflected by the polygon mirror 2 is reflected by the mirror 24, a synchronization detection sensor positioned by the same configuration as described above may be provided at a position indicated by reference numeral 25. it can. By using such a mirror, the degree of freedom of the installation position of the synchronization detection sensor is increased, and the position where the attachment and removal work can be easily performed can be set as the installation position of the synchronization detection sensor.
[0030]
【The invention's effect】
According to the first aspect of the present invention, in the optical scanning device having the optical deflecting means for deflecting the laser beam to scan the photosensitive member and the synchronous detection sensor for starting writing by the laser beam, the synchronous detection is performed. A support for supporting the sensor; positioning means for positioning the support on the stationary member; and a stationary member for biasing the support positioned on the stationary member by the positioning means toward the stationary member. Since the synchronous detection sensor is positioned by the positioning means and the support member that supports the synchronous detection sensor by the flat spring can be biased to the stationary member, the synchronous detection sensor can be easily attached and removed. It is possible to provide an optical scanning device that can
According to the first aspect of the present invention, since the stationary member is substantially integral with the casing that houses the light deflecting means, the optical scanning can reduce the number of parts if the stationary member is integrally formed with the casing. An apparatus can be provided, and if the immovable member is formed separately from the casing, an optical scanning device capable of increasing the degree of freedom in design can be provided.
According to the first aspect of the present invention, the leaf spring has an L-shaped cross section including a bottom portion having a first bent portion and a pressing portion having a second bent portion. 1 of the bent portion of the second bent portion are respectively engaged in said support to said stationary member, temporarily fixing the position you urging the support towards said stationary member in a state in which loose the screw When, a fixed position for fixing the base portion in operable position to urge the said synchronous detection sensor in the pressing portion toward the stationary member the support by tightening with the screw in the temporarily fixed position Therefore, regardless of the presence or absence of screws, the leaf spring and the support body will not fall from the stationary member, and the work efficiency of the synchronization detection sensor replacement work can be greatly improved and the synchronization detection sensor can be operated reliably. Can be fixed in a possible position It is possible to provide an optical scanning device.
[0031]
According to a second aspect of the present invention, the synchronization detection sensor, the support for supporting the synchronization detection sensor, the positioning means for positioning the support on the stationary member, and the stationary means by the positioning means. The leaf spring fixed to the stationary member that biases the support body positioned on the member toward the stationary member is provided outside the closed space of the optical scanning device. It is easy to replace the synchronization detection sensor provided on the support member urged by.
[0032]
According to the third aspect of the present invention, since the positioning means has the protrusion provided on the support and the immovable member and the engagement hole that engages with the protrusion, it is easy and accurate with a simple structure. It is possible to provide an optical scanning device capable of positioning the synchronization detection sensor.
[0033]
According to the fourth aspect of the present invention, since the leaf spring has a convex portion that presses the support, it is possible to provide an optical scanning device that can freely select a position at which stress acts on the support.
[0034]
According to the fifth aspect of the present invention, since the convex portion is provided in the vicinity of the positioning means, the stress can be applied to a relatively high strength portion such as when the abutting portion is provided. It is possible to provide a highly reliable optical scanning device that can avoid applying a force that causes distortion to the sensor, can accurately take a writing start timing, and is resistant to a change in normal time.
[0036]
According to the invention described in claim 6 , since the screwing direction of the screw is different from the direction in which the support is biased toward the stationary member by the leaf spring, the screwing position and direction can be freely set. To improve the work efficiency of the replacement work of the synchronous detection sensor by setting the screwing position on the surface where there are many screw fixings and the surface where there are few obstacles to work. It is possible to provide an optical scanning device that can improve productivity.
[Brief description of the drawings]
FIG. 1 is a plan view showing an optical scanning device to which the present invention is applied.
FIG. 2 is a perspective view of the optical scanning device shown in FIG.
3 is an enlarged perspective view of the optical scanning device shown in FIG. 1. FIG.
FIG. 4 is a side sectional view showing a temporary fixing position of a leaf spring.
FIG. 5 is a side sectional view showing a fixed position of a leaf spring.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical scanning device 2 Optical deflection | deviation means 8 Photosensitive body 10 Synchronization detection sensor 11 Support body 12 Immovable member 13a, 13b Projection part 14a, 14b Engagement hole 13a, 13b, 14a, 14b Positioning means 15 Leaf spring 15a Bottom 16 Screw 17a, 17b Convex part

Claims (6)

An optical scanning device including a light deflector for scanning the photosensitive member by deflecting the laser beam and a synchronization detection sensor for starting writing by laser beam,
A support for supporting the synchronization detection sensor; positioning means for positioning the support on the stationary member; and a stationary member for urging the support positioned on the stationary member by the positioning means toward the stationary member. And a leaf spring fixed with screws ,
In the stationary member casing and substantially integrally der Ru optical scanning device which accommodates the optical deflecting means,
The leaf spring has an L-shaped cross section including a bottom portion having a first bent portion and a pressing portion having a second bent portion, and the first bent portion is secondly attached to the stationary member. respectively engaged the bent portion to the support, the a temporary fixing position you urging the support towards said stationary member in a state in which loose the screw, the bottom portion in the temporarily fixed position optical scanning apparatus characterized by having a fixed position for securing the support in a position capable of operating the synchronization detection sensor is biased by the pressing portion toward the stationary member by tightening a screw. The optical scanning device according to claim 1,
The synchronization detection sensor, the support for supporting the synchronization detection sensor, the positioning means for positioning the support on the stationary member, and the support positioned on the stationary member by the positioning means. The optical scanning device according to claim 1, wherein the leaf spring fixed to the stationary member that is biased toward the stationary member is provided outside the closed space of the optical scanning device. The optical scanning device according to claim 1 or 2,
The optical scanning device, wherein the positioning means includes a protrusion provided on the support and the immobile member, and an engagement hole that engages with the protrusion. In the optical scanning device according to any one of claims 1 to 3,
The optical scanning device, wherein the leaf spring has a convex portion that presses the support. The optical scanning device according to claim 4.
An optical scanning device characterized in that the convex portion is provided in the vicinity of the positioning means. In the optical scanning device according to any one of claims 1 to 5 ,
The optical scanning device according to claim 1, wherein a screwing direction of the screw is different from a direction in which the support is urged toward the stationary member by the plate spring .

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