JP3612476B2 - CCD mounting structure and image reading apparatus employing the structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an attachment structure for attaching a CCD and an image reading apparatus employing the structure.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, digital copying machines, scanners, and the like are provided with an image reading device for reading a document. In this type of image reading apparatus, for example, a light source moves while irradiating a document placed on a contact glass, reflects reflected light from the document by a plurality of reflecting mirrors, and converges the reflected light by a lens. The document is read by being guided to the CCD and forming an optical image of the document on the light receiving surface of the CCD.
[0003]
In order to read a document well, the CCD must be positioned so that light from the lens is incident on the central axis of the light receiving surface. Therefore, the conventional CCD mounting structure is configured such that the height of the CCD can be adjusted.
FIG. 4 is an exploded perspective view showing the mounting structure of the conventional CCD 60. The CCD 60 is attached to a plate-like substrate 61, and this substrate 61 is attached to the holding plate 50 by an attachment base 51, an attachment member 52, a spring 66 and a screw 67.
[0004]
On the holding plate 50, a mounting base 51 that is long in the main scanning direction is disposed. The mounting base 51 is parallel to the lower plate 53 fixed on the holding plate 50, the outer piece 54 standing upright from one side 53a of the lower plate 53, and the upper plate 54a of the outer piece 54 in the same direction as the lower plate 53. This is a plate-like member having a substantially U-shaped cross section composed of an upper plate 55 projecting from the top. A pair of screw holes 57 are formed in the vicinity of both ends 53b and 53c of the lower plate 53 in the main scanning direction. The upper plate 55 has a long hole 62 extending in the main scanning direction at a position corresponding to the pair of screw holes 57 of the lower plate 53.
[0005]
On the mounting base 51, a mounting member 52 that is long in the main scanning direction is disposed. The attachment member 52 is a plate-like member having an approximately L-shaped cross section including an upper plate 58 and an outer piece 59 that hangs vertically from one side 58a of the upper plate 58. A long hole 63 extending in the main scanning direction is formed in the upper plate 58 at a position corresponding to the long hole 62 of the upper plate 55 of the mounting base 51. On the inner main surface 69 of the outer piece 59, a positioning projection 64 protrudes. A long hole 65 extending in the vertical direction is formed in the outer piece 54 of the mounting base 51 at a position corresponding to the protrusion 64, and the protrusion 64 is fitted along the long hole 65 so as to be slidable in the vertical direction. Thereby, positioning of the CCD 60 in the main scanning direction is achieved.
[0006]
A pair of compression coil springs 66 is disposed between the upper plate 55 of the mounting base 51 and the upper plate 58 of the mounting member 52 so that the axis passes through the long hole 62 and the corresponding long hole 63. The The pair of height adjusting screws 67 are screwed into the screw holes 57 through the long holes 63 of the attachment member 52, the compression coil spring 66 and the long holes 62 of the attachment base 51, so that the attachment member 52 is attached to the attachment base 51. It is done.
A pair of presser springs 68 having a substantially L-shaped cross section are provided on both side end surfaces 54 b and 54 c of the outer piece 54 of the mounting base 51, and the outer piece 59 of the mounting member 52 is in close contact with the outer piece 54 of the mounting base 52. It is supposed to let you.
[0007]
Through holes 70 and 71 are formed in positions corresponding to the CCD 60 in the outer piece 59 of the mounting member 52 and the outer piece 54 of the mounting base 51. By attaching the substrate 61 to a predetermined position of the attachment member 52, the reflected light of the original is received by the light receiving surface 60 a of the CCD 60 through the through holes 71 and 70.
In this CCD 60 mounting structure, the mounting member 52 is displaced in the vertical direction by tightening or loosening the height adjusting screw 67 so that the reflected light of the original is incident on the central axis of the light receiving surface 60a of the CCD 60. be able to. When the height adjustment screw 67 is tightened to reduce the height of the CCD 60, the screw tightening force of the height adjustment screw 67 is large, and the amount of compression of the compression coil spring 66 is large, so that the spring pressing force is large. Therefore, the back of the mounting member 52 is small and strong against vibration.
[0008]
[Problems to be solved by the invention]
However, when the height adjusting screw 67 is loosened to increase the height of the CCD 60, the tightening force of the height adjusting screw 67 is small and the compression amount of the compression coil spring 66 is small, so the spring pressing force is small. . Therefore, the mounting member 52 has a large backlash and is susceptible to vibration.
In this case, the optical image formed on the light receiving surface 60a of the CCD 60 cannot be read satisfactorily, and for example, character blur may occur.
[0009]
The present invention has been made under such a background, and an object thereof is to provide a CCD mounting structure which is resistant to vibration and an image reading apparatus employing the structure.
[0010]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve the above object, the invention according to claim 1 is a mounting structure for a CCD extending in the main scanning direction, which is a member which is fixed in the main scanning direction and is long in the vicinity of both ends in the longitudinal direction. A mounting base having a pair of insertion protrusions and a member elongated in the main scanning direction to which the CCD is attached, and a pair of insertion holes into which the insertion protrusions can be inserted are formed at positions corresponding to the insertion protrusions. A pair of springs that are attached to the attachment member having the lower plate and the insertion protrusion that is inserted through the insertion hole and presses the attachment member toward the attachment base. A main plate to be attached, and a pair of leg plates that protrude from a pair of opposite sides of the main plate so as to extend in the sub-scanning direction in a plan view, and whose front ends are in contact with the upper surface of the attachment member. A bent A switch-like, the tip of one leg plate of said pair of leg plate includes a pair of springs positioning projection for positioning the spring is formed with respect to the mounting member, the mounting base in the longitudinal direction A pair of height adjusting screws that are screwed in the vicinity of both ends and have a contact surface that contacts the lower surface of the lower plate to determine the height of the mounting member relative to the mounting base. When tightened, the contact surface is lowered and the mounting member is lowered by the pressing force of the pair of springs. When the pair of height adjusting screws are loosened, the contact surface is raised and the mounting member is moved to the pair of springs. The CCD mounting structure is characterized in that it is lifted against the pressing force.
[0011]
According to this configuration, when the height adjusting screw is tightened, the contact surface is lowered, the mounting member is lowered by the pressing force of the spring, and the height of the CCD is lowered. At this time, since the interval between the mounting base and the lower plate of the mounting member is narrowed, the mounting member has a small backlash and is resistant to vibration. On the other hand, when the height adjusting screw is loosened, the contact surface rises and the mounting member lifts against the pressing force of the spring, and the height of the CCD increases. At this time, since the amount of contraction of the spring is large and the spring pressing force is large, the back of the mounting member is small and strong against vibration. Accordingly, it is possible to provide a CCD mounting structure that is resistant to vibration both when the height of the CCD is high and when it is low.
Further, since the pair of leg plates extending in the sub-scanning direction in a plan view elastically presses the mounting member, it is possible to prevent the mounting member from rattling in the sub-scanning direction. Therefore, it is possible to provide a CCD mounting structure that is more resistant to vibration.
[0012]
Further, a second aspect of the present invention, an optical system for guiding the reflected light of the document, an image reading apparatus including a CCD having a light receiving surface for imaging the reflected light, CCD according to claim 1, wherein The image reading apparatus is provided with the mounting structure.
[0013]
According to this configuration, it is possible to provide an image reading apparatus employing a CCD mounting structure that exhibits the above-described effects. In this image reading apparatus, it is possible to satisfactorily read an optical image formed on the light receiving surface of the CCD, and character blurring can be prevented.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1A is a schematic cross-sectional view showing a part of an internal configuration of a copying machine 1 including an image reading apparatus according to an embodiment of the present invention. An image reading unit 4 as an image reading device including an optical system 2 and a CCD 3 is disposed on the upper side of the copying machine 1. The image reading unit 4 has a box-shaped housing 5 in which the optical system 2 and the CCD 3 are accommodated. Above the optical system 2, a transparent contact glass 17 serving as a document placement table is disposed.
[0015]
The optical system 2 includes a light source 6 that is long in the main scanning direction (direction perpendicular to the paper surface in FIG. 1A), a first reflecting mirror 7 that reflects reflected light from the document, a second reflecting mirror 8, and a third reflecting mirror. The reflecting mirror 9 and the lens 10 for imaging the reflected light of the third reflecting mirror 9 on the light receiving surface 31 of the CCD 3 are included.
The CCD 3 is disposed on a holding plate 11 that is long in the main scanning direction and is fixed to the bottom plate 5 a of the housing 5. The light receiving surface 31 of the CCD 3 is directed to the third reflecting mirror 9 side.
[0016]
When copying is performed, the light source 6 moves in the sub-scanning direction (left-right direction in FIG. 1A) while irradiating the document. The reflected light of the original is guided to the CCD 3 by the first reflecting mirror 7, the second reflecting mirror 8, the third reflecting mirror 9 and the lens 10, and an original image is formed on the light receiving surface 31 of the CCD 3. When the light source 6 moves, the first reflecting mirror 7 moves together with the light source 6, and the second reflecting mirror 8 and the third reflecting mirror 9 move in the same direction as the light source 6 at half speed. As a result, the optical path length from the document to the CCD 3 is kept constant. The original is read by a combination of electrical main scanning by the CCD 3 and sub scanning of the original by moving the light source 6 in the sub scanning direction.
[0017]
The image data read by the CCD 3 is converted into digital data by an image processing unit (not shown), and then sent to an LSU (laser scanning unit). The laser light is turned on and off on the surface of the main charged photoreceptor according to the image signal. Irradiation forms a so-called electrostatic latent image on the surface of the photoreceptor. The electrostatic latent image on the surface of the photoreceptor is developed into a toner image by a developing unit (not shown), and the toner image is transferred onto a sheet to form an image.
[0018]
FIG.1 (b) is a schematic diagram which shows the optical arrangement | positioning of Fig.1 (a). The image reading area length RLN must be less than or equal to the width of the contact glass 17 in the main scanning direction. The lens 10 is arranged at a position where a line segment corresponding to the document reading area length RLN on the contact glass 17 can be projected on the entire width of the light receiving surface 31 of the CCD 3. The reduction / enlargement copying is performed by a predetermined amount of movement of the lens 10, the second reflecting mirror 8, and the third reflecting mirror 9, or by digital data processing in an image processing unit (not shown).
[0019]
In order to read the original satisfactorily, the CCD 3 must be positioned so that the light from the lens 10 is incident on the central axis of the light receiving surface 31.
FIG. 2 is an exploded perspective view showing the mounting structure of the CCD 3. The CCD 3 is attached to a plate-like substrate 12, and this substrate 12 is attached to the holding plate 11 by an attachment base 13, an attachment member 14, a spring 22 and screws 26, 36 and 40. The holding plate 11 has a pair of screw holes 11B arranged in the main scanning direction.
[0020]
On the holding plate 11, a plate-shaped mounting base 13 that is long in the main scanning direction is disposed. The attachment base 13 is formed with a pair of insertion holes 16 extending in the sub-scanning direction at positions corresponding to the screw holes 11B of the holding plate 11. The mounting plate 13 is positioned on the holding plate 11 by tightening screws 40 in the screw holes 11B of the holding plate 11 through the pair of insertion holes 16. In addition, a lower end surface 28 b of a columnar insertion protrusion 28 is coupled to the mounting base 13 outside the insertion holes 16. A screw hole 27 is formed in the upper end surface 28 a of the insertion protrusion 28.
[0021]
On the attachment base 13, a longitudinal attachment member 14 is disposed in the main scanning direction. The attachment member 14 is a plate-like member having a substantially L-shaped cross section including a lower plate 18 and an outer piece 19 standing upright from one side 18 b of the lower plate 18.
A fixing portion 32 for fixing the substrate 12 is formed on the outer piece 19. A screw hole (not shown) is formed in the fixing portion 32 at a position corresponding to the insertion hole 33 formed in the substrate 12, and the substrate 12 is fixed by tightening a screw in this screw hole through the insertion hole 33. A through hole 34 is formed in the outer piece 19 at a position corresponding to the light receiving surface 31 of the CCD 3, and the reflected light of the original is received by the light receiving surface 31 through the through hole 34.
[0022]
Insertion holes 20 a and 20 b are formed in the lower plate 18 at positions corresponding to the insertion protrusions 28 of the mounting base 13. Of the insertion holes 20a and 20b, one (the front side shown in FIG. 2) insertion hole 20a regulates the sliding of the mounting member 14 in the main scanning direction and positions the CCD 3 in the main scanning direction. Is. The other insertion hole 20b (the back side shown in FIG. 2) is a long hole extending in the main scanning direction. The diameter of the insertion hole 20 a and the width of the insertion hole 20 b in the sub-scanning direction substantially coincide with the outer diameter of the insertion protrusion 28 of the mounting base 13. The insertion protrusions 28 are inserted into the insertion holes 20a and 20b from below.
[0023]
A spring 22 is arranged from above on the upper end surface 28a of the insertion protrusion 28 inserted through the insertion holes 20a and 20b. The spring 22 includes a rectangular main plate 23 that abuts on the upper end surface 28a, and a pair of leg plates 24 that protrude from a pair of opposing sides among the four sides of the main plate 23, and the side shape is bent into three parts. It is arched.
An insertion hole 25 is formed in the approximate center of the main plate 23, and the spring 22 is attached by tightening the mounting screw 26 to the screw hole 27 through the insertion hole 25.
[0024]
The leg plates 24 are arranged so as to extend in the sub-scanning direction in plan view, and their tips 24a are in contact with the upper surface of the lower plate 18 in a state parallel to the main scanning direction. A positioning projection 29 is formed at the tip 24 a of the leg plate 24 on the outer piece 19 side, and a through hole 30 formed at a position corresponding to the positioning projection 29 in the vicinity of the coupling portion between the lower plate 18 and the outer piece 19, The spring 22 is positioned by fitting the positioning protrusion 29.
[0025]
In the mounting base 13, a pair of screw holes 35 are formed outside the insertion protrusions 28. A height adjustment screw 36 is screwed into the screw hole 35 from above, and the height adjustment screw 36 is interposed between the mounting base 13 and the lower plate 18. The height adjusting screw 36 includes a shaft portion 37 to be screwed into the screw hole 35, a columnar head portion 38 formed at the upper end of the shaft portion 37, and a screw projecting in the circumferential direction from the lower edge of the head portion 38. A flange 39 as a contact surface is included.
[0026]
The lower plate 18 is formed with an insertion hole 41 at a position corresponding to the head 38 of the height adjusting screw 36, the diameter of which substantially matches the outer diameter of the head 38. The height adjustment screw 36 has a head 38 inserted through the insertion hole 41, and the lower plate 18 pressed downward by the spring 22 from below while the upper surface of the flange 39 is in contact with the lower surface of the lower plate 18. I support it.
In the present embodiment, the pair of leg plates 24 extending in the sub-scanning direction in a plan view elastically presses the mounting member 14, so that the mounting member 14 can be prevented from rattling in the sub-scanning direction.
[0027]
FIG. 3 is a schematic side view showing the mounting structure of the CCD 3. In this CCD 3 mounting structure, the height of the CCD 3 can be adjusted by tightening or loosening the height adjusting screw 36 so that the light from the lens 10 is incident on the central axis of the light receiving surface 31. .
When the height of the CCD 3 is lowered, the flange 39 is lowered by tightening the height adjusting screw 36. Along with this, the lower plate 18 of the attachment member 14 is pressed and lowered by the leg plate 24 of the spring 22 to be in a state as shown in FIG. In this state, the gap between the mounting base 13 and the lower plate 18 of the mounting member 14 is narrower than that in the state shown in FIG .
[0028]
When the height of the CCD 3 is increased, the flange 39 is raised by loosening the height adjusting screw 36. Along with this, the lower plate 18 of the mounting member 14 is lifted against the pressing force of the spring 22, and the state shown in FIG. In this state, since the amount of contraction of the spring 22 is large and the spring pressing force is large, the mounting member 14 has a small backlash and is strong against vibration.
The feature of the present invention resides in that the structure is strong against vibration both when the height of the CCD 3 is high and when it is low. In the image reading apparatus employing the CCD 3 mounting structure, an optical image formed on the light receiving surface 31 of the CCD 3 can be read satisfactorily, and character blurring can be prevented.
[0029]
The present invention is not limited to the contents of the above embodiments, and various modifications can be made within the scope of the claims. For example, in the present embodiment, the configuration in which the holding plate 11 is fixedly disposed on the bottom plate 5 a of the housing 5 and the CCD 3 is attached to the holding plate 11 has been described. However, the holding plate 11 is omitted, and for example, the CCD 3 is mounted on the bottom plate 5 a of the housing 5. The structure etc. which attach may be sufficient.
The spring 22 is not limited to the shape as described above, and may be a compression coil spring, for example. In this case, a pair of compression coil springs are put on the insertion protrusions 28 inserted into the insertion holes 20a, 20b, and the screw holes 27 of the insertion protrusions 28 have, for example, mounting screws whose head diameter is larger than the diameter of the compression coil springs. The upper end of the compression coil spring may be regulated by tightening. Even in this configuration, the mounting structure is strong against vibration both when the height of the CCD 3 is high and when it is low.
[0030]
In the present embodiment, the configuration in which the CCD 3 is attached to the outer piece 19 of the attachment member 14 has been described. However, the outer piece 19 may be omitted, and the CCD 3 may be attached to the lower plate 18.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an image reading unit.
FIG. 2 is an exploded perspective view showing a mounting structure of a CCD.
FIG. 3 is a schematic side view showing a mounting structure of a CCD.
FIG. 4 is an exploded perspective view showing a conventional CCD mounting structure.
[Explanation of symbols]
2 Optical system 3 CCD
4 Image reading unit (image reading device)
13 Mounting base 14 Mounting member 18 Lower plate 20a Insertion hole 20b Insertion hole 22 Spring 23 Main plate 24 Leg plate 24a Tip 28 Insertion projection 31 Light receiving surface 36 Height adjusting screw 39 Flange (contact surface)

Claims (2)

A CCD mounting structure extending in the main scanning direction,
A mounting base having a pair of insertion protrusions which are fixed members and are long in the main scanning direction and stand upright in the vicinity of both ends in the longitudinal direction;
An attachment member having a lower plate in which a pair of insertion holes through which the insertion protrusions can be inserted are formed at positions corresponding to the insertion protrusions, the member being long in the main scanning direction to which the CCD is attached;
A pair of springs that are attached to the insertion protrusions inserted through the insertion holes and press the attachment member toward the attachment base, and a pair of opposing main plates and the main plates attached to the insertion protrusions, respectively. A pair of leg plates projecting so as to extend in the sub-scanning direction in a plan view from the side of each of the above, and having a distal end abutting against the upper surface of the mounting member, and the side surface shape is an arch shape bent into three parts, A pair of springs formed with positioning protrusions for positioning the spring with respect to the mounting member at the tip of one leg plate among the leg plates;
A pair of height adjusting screws that are screwed in the vicinity of both ends in the longitudinal direction of the mounting base and have a contact surface that contacts the lower surface of the lower plate in order to determine the height of the mounting member relative to the mounting base;
When the pair of height adjustment screws are tightened, the contact surface is lowered and the mounting member is lowered by the pressing force of the pair of springs, and when the pair of height adjustment screws are loosened, the contact surface is raised. A CCD mounting structure, wherein the mounting member is lifted against the pressing force of the pair of springs. An optical system for guiding the reflected light of the document;
An image reading apparatus including a CCD having a light receiving surface for imaging the reflected light,
An image reading apparatus comprising the CCD mounting structure according to claim 1.

Images