JP3070103B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reading a sensor substrate on which a reading sensor is mounted, by sub-adjusting the position of the sensor substrate within a predetermined accuracy with respect to a reference of the base plate beforehand and mounting the substrate on the base plate. The present invention relates to an image reading apparatus having a reduction optical system that constitutes a sensor assembly, sends an optical image of a document image to an optical lens by a transmission unit, and reduces the image by the optical lens to form an image on a reading sensor of the reading sensor assembly. It is.

[0002]

2. Description of the Related Art Conventionally, digital copying machines, image scanners, facsimile machines and the like use a digital reading device for reading an image of a document by a reading sensor. In this digital reading device, for example, a CCD (Charge Coupled Device) is used as a reading sensor, and the density of a document image is converted into a level of an electric signal.

FIG. 11 is a diagram schematically showing an example of a reduction optical system of an image scanner portion of a copying machine using a digital reading device. As shown in FIG. 11, the reduction optical system in the image scanner portion of the copying machine receives a light emitting section 02 for irradiating light on a document (not shown) placed on a document table 01 and reflected light from the document. A first traveling body 04 having a first mirror 03, a second mirror 05 receiving reflected light transmitted from the first mirror 03, and the second mirror 0
And a second traveling body 07 having a third mirror 06 for receiving the reflected light transmitted from the first and second traveling bodies 5, and these first and second traveling bodies 04 and 07 are respectively moved along guide rails 08 and 09. It has become. The traveling speed of the second traveling body 07 is set to の of the traveling speed of the first traveling body 04, and the first traveling body 04 constitutes a full rate carriage,
The second traveling body 07 constitutes a half rate carriage. Then, the original is scanned by the first traveling body 04, the optical image is sent to the optical lens 010 by the first, second and third mirrors 03, 05, 06, and the optical image is further read by the optical lens 010 onto the reading sensor 011. Image.

When such a reduction optical system is developed on the same plane as shown in FIG. 12, an image of a document on the document table 01 is magnified by an optical lens 010 at a magnification N (N <1).
And the image is formed on the reading sensor 011. The reading sensor 011 is attached to the main body of the copying machine via a sensor plate or the like. In this case, if the reading sensor 011 is not accurately attached to a predetermined attachment position, a particularly good resolution MTF (Modulation Transfer Function) characteristic is obtained. For example, the reading sensor 011 must be accurately mounted at a predetermined mounting position.

For this purpose, it is necessary to adjust the mounting position of the reading sensor 011 with high precision, and to mount the reading sensor 011 at a predetermined mounting position as accurately as possible. The conventional mounting position adjusting device for the reading sensor 011 includes a reading sensor 01.
Attach the sensor board to which the 1 is attached to the adjustment base plate,
This adjustment base plate is attached to a sensor plate fixed to the copying machine main body via two adjustment middle plates so as to be adjustable in three-dimensional directions and their rotation directions. Then, the position adjustment is performed by moving the adjustment base plate and the adjustment middle plate in each direction by the respective adjustment screws. When actually adjusting the position, the reference pattern is read by the reading sensor 011, the video signal from the reading sensor 011 is supplied to the oscilloscope, and the waveform of the video signal is checked while finely adjusting each adjustment portion. , Reading sensor 0 with respect to document surface reference position
11 is positioned.

However, this position adjusting device has a problem that the structure is complicated, the number of parts is large, the cost is high, and the adjusting method is complicated, so that it takes a long time to adjust. In particular, the position adjustment is usually performed at the time of shipment at the factory, but it is necessary to adjust the position also at the sales destination. Therefore, the position adjustment device as described above should sufficiently cope with such position adjustment of the sales destination. Can not.

In view of the above, a sensor substrate to which a reading sensor is directly attached is fixed to a base plate after adjusting the position thereof within a predetermined accuracy in advance, thereby forming a reading sensor assembly.
Japanese Utility Model Laid-Open Publication No. Hei 2 (1990) proposes an image reading apparatus which solves the above-mentioned problem by attaching the reading sensor assembly to a reading optical system so as to be adjustable. According to this image reading device, when the reading sensor or the sensor substrate fails at the sales destination, the reading sensor can be attached with high accuracy only by replacing the reading sensor assembly.

By the way, it is desirable that the reading sensor assembly whose position is adjusted in advance in this way can be easily attached to the image reading optical system of the image reading apparatus main body. Conventionally, as a method of attaching an assembly such as a reading sensor assembly to an image reading apparatus main body, Japanese Utility Model Application
There is a method disclosed in JP-A-162342. In the assembly mounting method disclosed in this publication, an assembly of an optical lens and a reading sensor is connected to a first traveling body and a second traveling body.
It is attached to the lower surface of the guide with the traveling body.

[0009]

However, if the mounting portion of the assembly is provided on the guide portions of the first and second traveling bodies, the traveling of the first and second traveling bodies may be hindered. Conceivable. Further, if the assembly is mounted on the lower surface of the guide portion, the mounting and replacement of the assembly becomes troublesome. In particular, it is necessary to position the assembly with predetermined accuracy with respect to the optical axis of the reading optical system, so that attachment and replacement of the assembly becomes even more difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and has as its object to mount a reading sensor without hindering the traveling of a traveling body and to mount and replace a reading sensor assembly with a predetermined accuracy. It is an object of the present invention to provide an image reading apparatus which can be easily performed by using the image reading apparatus.

[0011]

In order to solve the above-mentioned problems, an image reading apparatus according to a first aspect of the present invention includes a reading sensor assembly provided with a reading sensor and an optical image of a document image. And a reduction optical system for transmitting the light to the optical lens and reducing the image by the optical lens to form an image on the reading sensor of the reading sensor assembly. And the transmission means has a traveling body on which a mirror is mounted, and a guide member having a guide portion on which the traveling body travels is provided, and at a portion other than the guide portion of the guide member,
An attachment portion for the reading sensor assembly is provided. Thus, the reading sensor assembly can be attached to the image reading apparatus main body without hindering the running of the running body. Further, the mounting portion is used as a reinforcing member for the guide member. Thereby, the rigidity of the guide member increases, so that the flatness of the guide portion on which the traveling body travels is improved. Therefore, the optical axis is hardly displaced while the traveling body is traveling, and the reading accuracy is improved.

[0012]

[0013]

Further, in the invention of claim 2, the reading sensor assembly is attached to an attaching portion of the guide member from above. Thus, the attachment / replacement of the reading sensor assembly is further simplified, and the attachment accuracy can be reliably maintained at a predetermined accuracy.

Further, in the invention according to claim 3, the guide member having the guide portion and the mounting portion is formed by a single member. As a result, the number of components is reduced, and the number of manufacturing steps can be reduced.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of the image reading apparatus according to the present invention. In this embodiment, a case where the present invention is applied to a color copying machine will be described as an example.

As shown in FIG. 1, a reading sensor 2 and an optical lens 3 are provided on a base plate 1. This base plate 1 is provided between a pair of frames 4 and 5 extending parallel to the sub-scanning direction of the main body of the color copying machine. And mounted so as to be adjustable in the sub-scanning direction, that is, in the optical axis direction (x-axis direction) by screws (not shown) penetrating two pairs of long holes 6, 7, 8, 9 provided on both side edges. It is supposed to be.

Further frames 4 and 5 is set to a predetermined length L ₁ as shown in FIG. 2, along with their top is formed in a U shape, and downward from the U-shaped portion in a substantially central portion projecting portion of the length L ₂ so as to project inwardly between a pair of frames 4 and 5 are formed, and a single member. As shown in FIG. 3A in an enlarged manner, a first guide portion 5a on which a first traveling body 61 of a scanner of the image reading apparatus travels while being guided is provided on the upper surface of the upper horizontal portion of the U-shaped portion of the frame 5. And a second traveling body 62 of a scanner in the image reading device is guided and travels on the upper surface of the lower horizontal portion of the U-shaped portion of the frame 5 as shown in FIG. A guide portion 5b is formed.

Further, as shown in FIG.
The base plate 1 to which the reading sensor 2 and the optical lens 3 are attached is attached to the projecting portion by screws. That is, the protruding portion serves as a mounting portion 5c for the reading sensor 2 and the optical lens 3. Note that the other frame 4 is also provided with first and second guide portions 4a, 4b and a mounting portion 4c similar to the first and second guide portions 5a, 5b and the mounting portion 5c, respectively. And this base plate 1
The mounting portion 4 is located inside the pair of frames 4 and 5 from above.
c, 5c and fixed.

The protruding portions serving as the mounting portions 4c and 5c are reinforcing members for the U-shaped portions of the pair of frames 4 and 5, and the reinforcement increases the rigidity of the U-shaped portions of the frames 4 and 5. ing. Due to this increase in rigidity, the first and second
The planarity of the guide portions 5a and 5b is further improved. In this case, in order to maintain the first and second guide portions 5a, the flatness of 5b reliably, the length L ₂ of the projecting portion is 1/2 or more of the length L ₁ of the frame 4, 5 (L ₂ ≧ L ₁ /
It is desirable to set to 2).

As shown in FIG. 4, the reading sensor 2 has pixel rows 2a, 2b and 2c formed by color filters having respective spectral sensitivities of red (R), green (G) and blue (B). The sensor is formed as a three-line sensor, and attached to the sensor substrate 10 as shown in FIGS. The sensor substrate 10 is composed of two mounting screws 11 and 12, adjustment stud screws 13 and 14, and mounting adjustment nut 15,
A reading sensor assembly 18 is configured by being attached to a mounting base plate 17 by 16. The mounting of the sensor substrate 10 and the mounting base plate 17 will be described in further detail. As shown in FIG. 7, the sensor substrate 10 has a mounting screw 11 penetrating therethrough and having a diameter larger than the outer diameter of the mounting screw 11. Hole 19 and FIG.
As shown in the figure, holes 20 and 21 for position adjustment are respectively formed. Although not shown, a hole similar to the hole 19 through which the mounting screw 12 penetrates is formed in the sensor substrate 10.

As shown in FIGS. 8 and 9, a hole 22 for transmitting the optical image from the optical lens 3 is formed substantially in the center of the mounting base plate 17, and a stud fitting mounting hole is provided. 23 and 24 are provided. Studs 25 and 26 are fitted and fixed in the stud fitting mounting holes 23 and 24, respectively. As shown in detail in FIG. 7, the stud 25 is formed in a cylindrical shape having a hole 27 through which the adjusting stud screw 13 slidably passes, and a flange 28 is formed on the outer periphery thereof. One surface of the flange 28 is in contact with the inner surface of the mounting base plate 17, and the stud 25 is fixed to the mounting base plate 17. The stud 26 is similar to the stud 25. Further, through holes 32 and 33 for mounting screws for mounting the mounting base plate 17 to the position adjusting and mounting device 39 as described later, and position adjusting holes 34 and 35, as described later. Are drilled respectively.

Further, as shown in FIG. 5, a flange 36 is formed by bending the upper end edge of the mounting base plate 17, and the rigidity of the mounting base plate 1 is enhanced by the flange 36. The flange 36 is attached to the mounting base plate 17 and the sensor substrate 10.
And flare light coming from the outside toward the reading sensor 2 is reflected by the flange 36 and is prevented from entering the reading sensor 2. Have been. The flange 36 also prevents foreign matter such as dust from entering the reading sensor 2 from the outside.

In order to assemble the reading sensor assembly 18, in FIG. 7, the adjusting stud screw 13 is first fitted with the spring 37 contracted between the flange 28 of the stud 25 and the head 13a of the adjusting stud screw 13. It is made to penetrate the hole 27 of the stud 25, and is attached to the stud 25 by the attachment adjusting nut 15. Similarly, the other adjustment stud screw 14 is attached to the stud 26 by the attachment adjustment nut 16 with a spring 38 interposed between the other adjustment stud screw 14 and the stud 26. Next, the mounting screw 11 is passed through the hole 19 of the sensor substrate 10 to which the reading sensor 2 is mounted, and is screwed into a female screw hole formed on the head 13a of the adjusting stud screw 13 and mounted in the same manner. By screwing the screw 12 to the head of the adjusting stud screw 14, the sensor substrate 10 is connected to the adjusting stud screw 1.
Attach to 3,14.

In this case, before fixing the sensor substrate 10 to the adjusting stud screws 13 and 14, the position of the sensor substrate 10 is adjusted in advance. As the position adjustment, first, the skew adjustment of the sensor substrate 10 is performed. Do. That is, with respect to the reference of the mounting base plate 17 (for example, the through holes 32 and 33 can be used as the reference), directions other than the optical axis direction (x-axis direction), that is, the y-axis direction and the z-axis direction in FIG. After the sub-adjustment of the relative position of the sensor substrate 10 with a predetermined accuracy in advance, the sensor substrate 10 is fixed to the adjustment stud screws 13 and 14. For this position adjustment, a sub-adjustment jig disclosed in Japanese Utility Model Laid-Open Publication No. Hei 2- is used.
1, 34, 35, and can be performed by the adjustment method disclosed in the publication. Therefore, description of the position adjustment is omitted.

Next, adjustment in the optical axis direction, that is, adjustment of the MTF is performed. This adjustment is performed by appropriately rotating the mounting adjustment nuts 15 and 16 so that the reference of the mounting base plate 17 (for example,
The position of the sensor substrate 10 in the optical axis direction (x-axis direction) with respect to the outer surface 17a of the mounting base plate 17 can be used as a reference surface with a predetermined accuracy. In that case,
Adjustment stud screws 13 and 14 and mounting adjustment nut 1
Since adjustment in the x-axis direction is performed by the steps 5 and 16, fine adjustment is possible. Then, the play between the stud 25 and the adjusting stud screw 13 is absorbed by the springs 37 and 38 and the loosening is prevented, and the position of the sensor substrate 10 in the optical axis direction is securely held at the adjusted position. You.

Thus, the sensor substrate 10 is mounted on the mounting base plate 1.
The reading sensor assembly 18 which is sub-adjusted in advance in the x-axis direction, the y-axis direction, and the z-axis direction with respect to the reference 7 is configured. Then, by performing skew adjustment first and then performing MTF adjustment in position adjustment, there is an advantage that the previously adjusted skew does not change even after MTF adjustment.

As shown in FIG. 7, in this embodiment, an adjustment margin A is provided between the stud 25 and the adjustment stud screw 13 to enable the position adjustment in the optical axis direction. By setting the adjustment margin A, it is possible to prevent problems such as inability to adjust or excessive adjustment. The studs 25 and 26 are provided by providing the adjustment margin A.
The play generated between the adjusting stud screws 13 and 14 is absorbed by the springs 37 and 38, respectively.

Sensor substrate 10, ie, reading sensor 2
Sensor assembly 18 whose position has been pre-adjusted
As shown in FIG. 1, the rotational direction A around the y-axis direction, the z-axis direction, and the x-axis (shown in FIG. 10) and the rotational direction around the z-axis (same as above) are applied to the base plate 1 by the position adjusting and mounting device 39. Is mounted so that the position can be adjusted.

On the other hand, as shown in FIG.
The optical lens 3 is fixed to the base plate 1 by a support casing 55 so that the position of the optical lens 3 can be adjusted in the optical axis (x-axis) direction.

Further, the above-mentioned first traveling body 61 is hung on a pair of frames 4 and 5 and is provided so as to be guided along the first guide portion 5a so as to be able to travel. The second traveling body 62 is hung over a pair of frames 4 and 5, and is provided so as to be able to travel while being guided along the second guide portion 5b. These first and second traveling bodies 61 and 62 are respectively the same as the conventional first traveling body shown in FIG.
And the first traveling body 61 has a light emitting unit 02 and a first mirror 03, and the second traveling body 61 has a second and third mirrors 05 and 06. Have.

The position adjustment of the reading sensor assembly 18 in which the positions of the reading sensor 2 in the x-axis direction, the y-axis direction, and the z-axis direction are sub-adjusted, as shown in FIG. Direction; optical axis direction) a, rotation direction around x-axis a, y-axis direction (sub-scanning direction) c, rotation direction around y-axis (tilt direction) d, z-axis direction (vertical direction) e, around z-axis This is performed in six directions of the rotary power. These adjustments are not directly related to the present invention and will not be described.

In the above-described embodiment, the case where the present invention is applied to a color copying machine is described as an example. However, the present invention can be applied to other image reading apparatuses. Read sensor 2
Is constituted by a three-line sensor for color, but it goes without saying that the present invention can also be applied to the case of a one-line sensor for black and white.

[0035]

As is apparent from the above description, according to the first aspect of the present invention, since the mounting portion of the reading sensor assembly is provided in a portion other than the guide portion of the guide member, the traveling body can be moved. The reading sensor assembly can be attached to the image reading apparatus main body without any trouble.

Further, since the guide member is reinforced by the mounting portion, the flatness of the guide portion is improved. Therefore, the optical axis is hardly displaced while the traveling body is traveling, and the reading accuracy is improved.

[0037]

According to the second aspect of the present invention, since the reading sensor assembly is mounted on the mounting portion of the guide member from above, mounting and replacement of the reading sensor assembly is further simplified, and mounting accuracy is improved. Can be reliably maintained at a predetermined accuracy.

Further, according to the third aspect of the present invention, since the guide member having the guide portion and the mounting portion is formed as a single member, the number of parts is reduced, the number of manufacturing steps can be reduced, and the cost can be reduced. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing an attached state of a reading sensor assembly and an optical lens used in an embodiment of an image reading apparatus according to the present invention.

FIG. 2 is a plan view of a frame in this embodiment.

FIGS. 3A, 3B, and 3C are cross-sectional views taken along lines IIIA-IIIA, IIIB-IIIB, and IIIC-IIIC in FIG. 1, respectively.

FIG. 4 is a diagram showing a three-line sensor which is a reading sensor of the embodiment.

FIG. 5 is a plan view of a reading sensor assembly according to the embodiment.

FIG. 6 is a side view of the reading sensor assembly according to the embodiment.

FIG. 7 is a partially enlarged sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a front view of a mounting base plate in the reading sensor assembly.

FIG. 9 is a bottom view of the mounting base plate.

FIG. 10 is a diagram showing a position adjustment direction.

FIG. 11 is a schematic diagram showing an optical system in a conventional general image reading apparatus.

FIG. 12 is an expanded view of the optical system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base plate 4a, 5a ... 1st guide part, 2 ... Reading sensor, 3 ... Optical lens, 4, 5 ... Frame, 4a,
5a: 1st guide part, 4b, 5b ... 2nd guide part, 4c, 5
c: mounting portion, 10: sensor board, 13, 14: adjustment stud screw, 15, 16: mounting adjustment nut, 17:
Mounting base plate, 18 ... Reading sensor assembly, 25, 26 ...
Stud, 29: third adjustment plate, 36: flange (flare light shielding means), 37, 38: spring, 39
… Position adjustment and mounting device

Claims (3)

(57) [Claims] And 1. A reading sensor is provided reading sensor assembly, reduced to image and sends the optical lens by the transmission means of the optical image of the document image, the reading sensor of the reduction to the reading sensor assembly by said optical lens the image reading apparatus having an optical system, together with the transmission means includes a traveling body mirror is mounted, provided with a guide member having a draft in part the <br/> traveling body you run lines, the the draft inside other portions of the guide member, the mounting portion is provided in said reading sensor assembly, an image reading apparatus, wherein the attachment portion has a reinforcing member of the guide member. Wherein said image according to claim 1 Symbol placing the reading sensor assembly and being attached from above to the mounting portion of the guide member reader. 3. A pre-Symbol draft internal and claim 1 Symbol mounting the image reading apparatus of the guide member having a mounting portion, characterized in that it is formed by a single member.