JP3638544B2 - Image reading device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading apparatus such as a copying machine or a scanner.
[0002]
[Prior art]
Copiers and scanners are provided with an optical image reading unit for reading a document. The image reading unit includes a light source for illuminating a document, a moving optical system for guiding reflected light of the document illuminated by the light source to the lens unit, and a document guided by the moving optical system. Image forming optical system as a lens unit that forms an image of reflected light on a CCD, and various optical devices such as a photoreceptor represented by a CCD line sensor for optically reading a document image formed by the image forming optical system A system is provided. The one-dimensional image in the main scanning direction formed on the CCD line sensor is read in the sub-scanning direction by moving the light source in the moving optical system from the leading edge to the trailing edge of the document, and the original image is obtained as a two-dimensional image. Reading is achieved.
[0003]
The housing of such an image reading unit is usually in the form of a box including a bottom plate and four side plates including a front side plate, a rear side plate, and left and right side plates disposed around the bottom plate. The upper surface of the housing is made of contact glass for placing a document.
Various presses such as openings and screw holes for mounting various optical components such as the optical system and lens unit in the housing and bent portions for mounting the components are provided on the side plate and the bottom plate constituting the housing. Molding is applied, and even the side plates facing each other are specially pressed and handled as separate parts. These parts are connected using welding or screw means to form a housing.
[0004]
By the way, in order to correctly form an image of a document placed on the contact glass on the CCD light receiving unit, it is important that the various optical systems described above are adjusted (positioned) correctly. In particular, unless the light receiving portion of the CCD as a line sensor is parallel to the current width direction and adjusted to be perpendicular to the optical axis, main scanning and sub-scanning cannot be performed accurately and correct document image information cannot be obtained.
[0005]
Therefore, conventionally, a CCD line sensor is provided with an adjusting mechanism as disclosed in, for example, a previous application (Japanese Patent Laid-Open No. 2001-156990) according to the present application, and is configured so that it can be adjusted correctly in the manufacturing process.
[0006]
In this adjustment, a dedicated adjustment jig is often used. Specifically, an adjustment jig is placed on the upper surface of the scanner housing, and a CCD line sensor unit that is correctly positioned at a predetermined position inside the housing by the adjustment jig is fastened and fixed with a mounting screw. In this case, the correct CCD line sensor unit cannot be adjusted unless the adjustment jig is properly placed on the upper surface of the housing. Therefore, as positioning means for the adjustment jig, a positioning pin is provided on the lower surface of the jig and the above-mentioned is provided on the upper surface of the housing. A positioning hole is provided corresponding to the positioning pin.
[0007]
As positioning means comprising these pins and apertures, one side of the upper surface of the housing is set as a reference position (reference surface), and the parts related to various optical systems are adjusted based on this reference surface. At this time, a positioning pin and an opening are provided also on the other side facing the reference surface, but this other side is an opening on an adjustable long hole for ensuring a degree of freedom when placing the adjusting jig. Yes.
[0008]
[Problems to be solved by the invention]
In the conventional housing described above, the side plate and the bottom plate constituting the housing are processed as dedicated parts.
Furthermore, when the optical component adjustment method as described above is performed, the reference position (one side) and the adjustment position (the other side) exist on the upper surface of the scanner housing. As the perfect circle on the side and the long hole on the adjustment side must have separate positioning holes on the reference and adjustment side, a dedicated part design is required, and a separate press die is designed for that purpose. As a result, the production cost increases.
[0009]
SUMMARY An advantage of some aspects of the invention is that it provides an image reading apparatus that does not increase production costs.
It is another object of the present invention to provide an image reading apparatus capable of easily adjusting a CCD license sensor disposed inside a main body.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an invention of claim 1 is an image reading apparatus including a moving optical system, an imaging optical system, and a photoreceptor therein, and the image reading apparatus includes at least a bottom plate and four side plates. have constructed frame, a pair of side plates substantially located in parallel to the direction of movement of the moving optical system has have a substantially common pressing is performed shape of the side plate, substantially on top It has a horizontal upper surface, and on the upper surface, as a positioning means for placing the adjustment jig for adjusting the optical system or photoreceptor, a round hole having a narrower width than the diameter of the perfect circle and the perfect circle It is characterized by being provided with an opening provided with .
[0011]
According to the first aspect of the present invention, by making the pair of side plates substantially parallel to the moving direction of the moving optical system a common press-molded product, the larger one of the side plates constituting the housing is made common. Since it can be a part, it can greatly contribute to cost reduction. Further, since the positioning means for mounting the adjusting jig is also formed on the upper surfaces of the common pair of housing side plates, it can contribute to cost reduction in the press molding process. Further, since the opening formed in the upper surface of the housing side plate as a positioning means has a long hole portion and a perfect circle portion, the perfect circle portion can be used as a reference position and the long hole portion can be used as an adjustment position. Even when the shapes are shared, adjustment with a high degree of freedom is possible.
[0015]
The invention of claim 2 relates to the invention of claim 1 , characterized in that the perfect circle part of the opening is located on the inner side of the main body of the image reading device than the elongated hole part. According to the second aspect of the present invention, since the perfect circle portion serving as the reference position is positioned outside the side plate, a long hole narrower than the perfect circle portion is positioned in the bent portion of the side plate. As a result, the strength of the position system is highly adjusted.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic sectional view showing a part of a configuration of a copying machine including an image reading apparatus according to an embodiment of the present invention. An image reading unit 3 having an optical system 2 for reading an image of a document is disposed at the top of the copying machine main body 1. The image reading unit 3 has a box-shaped housing 4, and a transparent contact glass 5 serving as a document placement plate is fitted above the optical system 2. The optical system 2 includes a light source 6 that moves while illuminating the original, a mirror 7 that reflects light reflected from the original, and a lens 9 that converges the reflected light.
[0017]
An automatic document feeder 8 is disposed above the contact glass 5 so that the document can be automatically conveyed to the document reader. The automatic document feeder 8 also serves as a cover, and is configured to open from the back side to the upper front side so that the document can be manually placed on the contact glass 5. The automatic document feeder 8 is supported by the housing 4 of the image reading unit 3. When copying is performed, the light source 6 moves while irradiating the document. The current reflected light is guided in a predetermined direction by the mirror 7 and the lens 9, and an original image is formed on the CCD sensor 10. The CCD sensor 10 has a length in the main scanning direction (direction perpendicular to the paper surface of FIG. 1). Document reading is achieved by a combination of electrical main scanning by the CCD sensor 10 and document sub-scanning by movement of the light source 6 in the sub-scanning direction.
[0018]
The image read by the CCD sensor 10 is subjected to image processing, sent to an LSU (laser scanner unit) as an image signal, an electrostatic charge latent image is formed by a known electrophotographic process, and visualized as a toner image. The The toner image is transferred to a sheet and fixed to obtain a hard copy.
[0019]
2A and 2B are perspective views for explaining the configuration of the image reading unit 3 in a state where the housing 4 and main components are mounted, with the contact glass 5 and the optical system 2 removed. Show. In the figure, (a) is a perspective view seen from the front right side, and (b) is a perspective view seen from the front left side. FIG. 3 is a top view of only the housing. The configuration of the housing will be described with reference to these drawings.
[0020]
The housing 4 includes a bottom plate 11, a left side plate 12, a right side plate 13, a front side plate 14, and a rear side plate 15. The bottom plate 11 forms a bottom surface portion of the image reading unit 3 (see FIG. 1), and is made of a metal plate having a substantially rectangular planar shape. A plurality of protrusions are formed from the bottom surface by press molding to increase strength. ing.
Of the four side plates, the long front side plate 14 and the rear side plate 15 are press-molded as a common member. The front plate 14 corresponds to the front position of the image reading apparatus, and the rear plate 15 corresponds to the back direction. On the other hand, in this embodiment, the short left side plate 12 and the right side plate 13 are not a common press-molded product, but are exclusively molded. The four side plates 12, 13, 14, and 15 are all press-molded in a U-shaped cross section.
[0021]
The housing 4 is assembled by placing a bottom plate on the lower bent portion of the front side plate 14 and the rear side plate 15, and further folding the upper and lower bent plate portions of the front side plate 14 and the rear side plate 15 on the left side plate 12 and the right side plate 13. Assemble the parts so that they are pinched. Assembling is performed by welding the slit-shaped openings 20 formed in the bent portions of the left and right side plates 14 and 15 by welding.
Further, between the front plate 14 and the rear plate 15, a lens unit 22 as an imaging optical system and a mounting plate 24 for mounting a CCD sensor are also joined by welding means. The strength of the housing itself is also increased by the joining of the mounting plate 24.
[0022]
And the harness for connecting the screw hole which attaches a functional component, and an electrical component to the bottom plate 11, the left side plate 12, the right side plate 13, the front side plate 14, the rear side plate 15, and the mounting plate 24 constituting the housing 4 A wiring opening 26 and the like for passing through are formed.
The image reading unit 3 is configured by mounting various optical components on the housing 4 thus formed.
[0023]
The image reading unit 3 of this embodiment employs a well-known both-wire drive system that scans the moving optical system using two wires, and uses an illumination mirror unit frame (first frame) 30; A moving optical system such as a reflection mirror frame (second frame) 32 is reciprocated at a predetermined speed along the guide rail 34 by the rotation of the drive source 36.
The first frame 30 includes an illumination lamp 6 (see FIG. 1) as a light source, a reflector 39 (see FIG. 1) for efficiently irradiating the lamp on the contact glass, and a document image. A first mirror 7a (see FIG. 1) for guiding to the two-frame body 32 is provided. The second frame 32 is provided with a second mirror 7b and a third mirror 7c for inverting the original image guided by the first mirror 7a by 180 degrees and guiding it to the lens means.
[0024]
Next, a specific mechanism relating to the above-described wire drive will be described with reference to FIG. 2 described above and FIG. 4 schematically illustrating the wire winding structure, taking the wire on the back side of the housing as an example.
First, the round terminal 52 attached to one end of the wire 50 by a crimping means is hooked on a hook portion 54 (see FIG. 2) formed on the back side of the optical unit mounting plate 24 (see FIG. 2). And it hooks from the bottom to the groove | channel 56a of the back | inner side of the wire pulley 56 rotatably provided in the 2nd frame 32 (refer FIG. 1). In this way, the wire whose direction is changed by the wire pulley 56 is sandwiched and fixed by a wire locking portion (not shown) of the first frame 30. Next, the wire is hooked from above the optical wire pulley right 60 that is rotatably attached to a bent portion 58 that is bent inwardly of the right side plate 13 so as to be parallel to the moving direction of the moving optical system. Further, the wire is wound around the optical wire drum 64 attached to the optical system drive shaft 62 having the drive motor 36 at one end so as to rotate together with the drive shaft a plurality of times downward from the top, and then inside the left side plate. The optical wire pulley left 68 is hooked upward from below the bending portion 66 that is bent so as to be parallel to the moving direction of the moving optical system. The optical wire whose direction has been changed again is once again hooked on the wire pulley 56 of the second frame 32, and this time it is hooked from the bottom to the groove 56b on the near side and directed toward the left side plate 12 so The other end portion 76 of the optical wire is locked to the rectangular opening 72 formed on the side surface of the left side plate 12 via the optical wire spring 74 for tension adjustment.
Similarly, the optical wire on the front side of the housing 4 is attached so as to be symmetrical with respect to the central axis in the longitudinal direction of the image reading apparatus.
In this way, the first frame 30 moves at a predetermined speed between both ends of the contact glass as the drive shaft 62 rotates, and the second frame 32 is moved by the action of the optical wire pulley 56 to the first frame. A half section of the first frame 30 (substantially a half section of the contact glass) can be moved at a half speed.
[0025]
Next, returning to FIG. 2 and FIG. 3, attachment of the imaging optical system will be described.
The imaging optical means 80 including the lens unit 22 and the CCD sensor is fixed to the mounting plate 82 with the lens means 22 adjusted in position, and the CCD sensor is attached to the mounting plate 82 via an adjustment mechanism. It is configured to be fixed to the mounting plate 84. The imaging optical system 90 is attached with screws to four screw holes 92 provided on the mounting plate of the housing 4. In mounting, a dedicated jig is used to set the correct position with respect to the mounting plate, and then the mounting plate 82 is fixed with screws.
The imaging optical system 90 attached in this way adjusts the CCD sensor so that the CCD sensor is set at right angles to the optical axis through which the document image is guided to the CCD sensor and parallel to the document image (slit image). There is a need to.
[0026]
Specifically, the original unit including the adjustment original is placed on the bent portion of the front plate 14 and the rear plate 15 formed on the upper surface of the housing, and whether or not the image is correctly formed on the CCD line sensor is electrically checked. Detection is performed to set the unit itself and the CCD line sensor. At this time, it is adjusted whether or not the original is correctly imaged at the two ends A and B of the original placement surface, specifically, the home position A and the folding point B of the scanning exposure.
[0027]
In this adjustment, in this embodiment, all the adjustments are made with reference to the rear side plate 15. That is, the upper surface bent portions 101 and 102 of the front side plate 14 and the rear side plate 15 are provided with position restriction openings 110 (see FIG. 5) for correctly placing the adjustment jig unit and the original unit for adjustment at the reference position. Is formed.
[0028]
Since the front side plate 14 and the rear side plate 15 are formed by a common press-molded product, the position restricting opening 110 has a circular opening 112 to be a reference position and a degree of freedom with respect to the reference position. It comprises a slit-like long hole portion 114 that can be placed with a gap. The long hole portion 114 is larger than the diameter of the perfect circle portion 112 in the direction perpendicular to the moving direction of the moving optical system (the first frame body 30 and the second frame body 32) of the image reading device 3 described above. It is formed in a slit shape with a narrow width.
The perfect circle portion 112 is located inside the bent portion 102 on the upper surface of the side plate 15, and the slit-like long hole portion 114 is formed from the true circle portion 112 to the bent portion. The reason why the perfect circle portion 112 is positioned inside the upper surface is that the bending strength of the side plate 15 formed by press working is formed by the bent portion 102, so that the bent portion 102 has a narrower length. This is because by positioning the hole 114, the position restricting opening 110 can be formed without causing a decrease in strength.
[0029]
Here, with reference to FIG. 6, the placement of the original projection jig provided with the simulated original 117 as the adjustment jig 116 will be described.
As shown in FIG. 6, the adjustment jig 116 has a simulated original 117 on the lower surface, and is placed on the first frame 30 (see FIG. 1) by a projection light source 119 disposed inside the jig. This mounting position is a position corresponding to the home position A and the folded portion B of the first frame 30 in the housing 4 as described above.
[0030]
In addition, pins 120 whose tips are formed in a tapered shape are provided at both ends of the lower surface of the adjustment jig 116. Then, the pin 120 is inserted into the position adjustment opening 110 formed on the upper surface of the housing 4. At this time, the pin 120 is formed on the lower surface of the adjustment jig 116 and the document unit by using the perfect hole 112 of the rear plate 15 as a reference position and the long hole portion 114 of the front plate 14 as a second reference position. By inserting the protruding pins 120, each unit can be placed correctly. Thus, by setting the perfect circular aperture 112 as the reference position, an accurate position can be set, and the front plate 14 side uses the elongated hole portion 114, so that the pin 120 generated due to a slight molding error can be obtained. The error between can be absorbed.
[0031]
【The invention's effect】
As described above, according to the present invention, among the side plates constituting the housing of the image reading apparatus, the unilateral side plate positioned substantially parallel to the moving direction of the optical system is used as a common press-molded part. Costs can be reduced, and the cost of the entire apparatus can be effectively reduced. In addition, even when using an adjustment jig for mounting optical system components built into the image reading device, the side plate can be shared by using a specific shape that combines a perfect circle part and a long hole part as a position regulating opening. It becomes possible to do.
[0032]
[Brief description of the drawings]
FIG. 1 is a schematic view showing a part of a configuration of a copying machine including an image reading apparatus according to the present invention. FIG. 2 is a perspective view illustrating a configuration in a state where a housing and main components of an image reading unit are mounted. FIGS. 3A, 3B are views in which the viewing direction is changed. FIG. 3 is a top view of only the housing of the image reading unit. FIG. 4 is a schematic diagram for explaining the winding of the wire. FIG. 6 is an enlarged view of a position restricting opening formed on the upper surface of the housing of the image reading unit. FIG. 6 is a schematic diagram for explaining a method of attaching an adjustment jig using the position restricting opening.
3 Image reading device 4 Housing 11 Bottom plate 12 Left side plate 13 Right side plate 14 Front side plate 15 Rear side plate 22 Lens unit 30 First frame body 32 Second frame body 110 Position restriction opening 112 True circle portion 114 Long hole portion 120 Pin

Claims (2)

An image reading apparatus including a moving optical system, an imaging optical system, and a photoreceptor inside, the image reading apparatus having a frame composed of at least a bottom plate and four side plates, and the moving optics of the side plates with a pair of side plates substantially located in parallel to the moving direction of the system has have a shape substantially common pressing is performed, it comprises a substantially horizontal upper surface thereon, the optical system or the upper surface As the positioning means for placing the adjustment jig for adjusting the photoreceptor, an opening having a perfect circle part and a long hole part narrower than the diameter of the perfect circle part is provided. An image reading apparatus. Perfect circle section of the opening image reading apparatus according to claim 1, characterized in that located in the image reading apparatus main body internal side of the long hole portion.

Images