JP2013106243A - Image reading device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce size in a height direction and a sub-scanning direction of a scanning optical unit integrated with a reduction optical system so as to reduce the thickness, weight, and cost of an entire reading device.SOLUTION: An image reading device includes: a light source 115 for exposing a reading area in a main-scanning direction of a document; an image sensor 122 as reading means for reading reflection light from the document; reflection means having a plurality of mirrors 120a to 120e that sequentially reflect the reflection light from the document to guide the light to the image sensor 122; and an imaging lens 121 that forms an image from the reflection light reflected by the reflection means and guides the image to the image sensor 122. The light source 115, the image sensor 122, and a first mirror 1120a as a specific mirror are mounted on a travelling body 112 capable of travelling in a sub-scanning direction in order to scan the document, and other reflection means are arranged outside the travelling body 112.

Description

  The present invention relates to an image reading apparatus and an image forming apparatus.

  The image reading apparatus is classified into a reduction optical system and an equal magnification optical system according to an imaging method. The reduction optical system reduces an image of a document with a reduction lens, and reads this with a reduction sensor configured by a CCD (Charge Coupled Device) or the like. In the 1 × optical system, a 1 × magnification sensor composed of a CCD, a CIS (Contact Image Sensor) or the like is arranged close to the document surface, and an image is directly read from the document surface by the 1 × magnification sensor.

  The reduction optical system has a deeper depth of focus than the equal-magnification optical system and is advantageous for floating a document. Therefore, the reduction optical system can cope with image reading of books and three-dimensional objects. For this reason, multi-function machines (MFPs) having two or more functions, such as copying, printers, scanners, and fax machines, and high-end machines equipped with digital scanners are often equipped with this reduction optical system reader. Since the optical path length of the reduction optical system becomes long, a structure in which the optical path is folded using a plurality of mirrors is adopted in order to make the apparatus compact.

  The image reading apparatus of the reduction optical system is further classified into a differential type having two traveling bodies as a traveling body for scanning an original and an integrated type having a single traveling body (for example, Patent Document 1 (Japanese Patent Laid-Open Publication No. 2003-32083). 2010-4365 gazette) and FIG. 3 and FIG. 16).

  In the differential type, as shown in FIG. 37, the first traveling body 511 is moved in the sub-scanning direction at a double speed of the second traveling body 512 in order to keep the optical path length (conjugate length) constant. Then, the original placed on the platen glass 514 is exposed by a light source 513 mounted on the first traveling body 511, and reflected light from the document is reflected on a plurality of mirrors M1, M2, M3 of the first traveling body 511 and the second traveling body 512. And is guided to an image sensor 515 using a CCD as a reading means through an imaging lens 514 disposed in the apparatus.

  The differential type has a weak point in that the mirrors M1, M2, and M3 are mounted on the two independent traveling bodies 511 and 512, so that relative mirror surface tilting easily occurs. The first traveling body 511 and the second traveling body 512 are driven by a wire system that realizes a double speed differential based on the principle of a moving pulley or a timing belt system that realizes a double speed differential based on a gear ratio.

In the integrated type, a light source 522, a plurality of mirrors M1 to M5, an imaging lens 523, and an image sensor 524 are mounted on a single traveling body 521 as shown in FIG. The integral type has a single traveling body 521, so the drive mechanism is simpler than the differential type, and the mirrors M1 to M5 are not easily tilted.
However, since the optical path length is made as long as possible by arranging a large number of mirrors M1 to M5 in a limited space in the traveling body 521, the structure is complicated and the traveling body 521 extends in the height direction and the sub-scanning direction. Larger and heavier.

In addition, it is essential to control the moving motor in the sub-scanning direction and to design the mechanical strength of the apparatus in consideration of the shaking of the entire apparatus due to the movement of the heavy traveling body 521.
Furthermore, since the traveling body 521 is heavy, it is usually necessary to connect the driving means to both ends of the traveling body 521 in the main scanning direction to drive both sides.
As a driving method of the traveling body 521, there are a wire driving method and a timing belt driving method.

  The reduction optical system has a complicated structure compared to the equal magnification optical system. Especially, the integrated type has a large number of mirrors in the height direction and the sub-scanning direction because a large number of mirrors are arranged in a limited space in the traveling body. Becomes heavy. In addition, since the traveling body is heavy, it is necessary to drive the traveling body on both sides, the control of the motor that drives in the sub-scanning direction becomes complicated, and the housing of the reading apparatus must also have high strength. Becomes larger.

  The present invention has been made to solve the above-described problems. The reduction type optical system integrated scanning optical unit is made compact in the height direction and the sub-scanning direction, thereby reducing the thickness and weight of the entire reading apparatus. The purpose is to reduce costs.

  The present invention provides a light source for exposing a reading range of a document in the main scanning direction, a reading unit that reads reflected light from the reading range of the document, and sequentially reflects reflected light from the reading range of the document to Identification of a reflecting means having a plurality of mirrors for guiding to the reading means, an imaging lens for imaging the reflected light reflected by the reflecting means and guiding it to the reading means, the light source, the reading means, and the reflecting means And a traveling body that is movable in the sub-scanning direction to scan the document, wherein the reflecting means excluding the specific mirror mounted on the traveling body includes the reflection means, An image reading apparatus disposed outside a traveling body.

  In the present invention, the reflecting means having a plurality of mirrors that sequentially reflects the reflected light from the reading range of the document and guides it to the reading means is arranged outside the traveling body except for the specific mirror mounted on the traveling body. The traveling body can be reduced in weight and size, and the entire reader can be reduced in weight and thickness.

  Further, by arranging the reflecting means outside the traveling body, the degree of freedom in designing the optical path is increased, and by extending the optical path length with a small number of mirrors, a conventional reduction optical system integrated image reading apparatus having a single traveling body Therefore, it is possible to use an imaging lens having a longer focal point, narrowing the angle of view, and realizing a reading apparatus that is less affected by performance degradation due to component processing errors.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view showing an appearance of an image reading apparatus according to an embodiment of the present invention. FIG. 3 is a perspective view illustrating a state in which a scanner frame portion and a scanner cover portion constituting the housing of the image reading apparatus according to the embodiment of the present invention are separated. 1 is an overall schematic side view of an image reading apparatus according to an embodiment of the present invention. 1 is a plan view of the inside of an image reading apparatus according to an embodiment of the present invention. It is a BB line arrow sectional view of Drawing 4A. It is a center sectional view of the traveling body of the image reading apparatus according to the embodiment of the present invention. FIG. 3 is a front view in the sub-scanning direction of the traveling body of the image reading apparatus according to the embodiment of the present invention. FIG. 3 is a perspective view of a scanner frame portion of the image reading apparatus according to the embodiment of the present invention. FIG. 5 is a side view of the scanner frame unit of the image reading apparatus according to the embodiment of the present invention viewed from the sub-scanning direction. (A), (b), and (c) are the top view, the front view, and the side view of the mirror attachment member attached to the side surface of the scanner frame part of the image reading apparatus which concerns on embodiment of this invention. It is a front view of the screw which attaches a mirror attachment member. It is a perspective view of the edge part of a mirror attachment member. It is a side view of the edge part of a mirror attachment member. (A)-(d) is the front view of the edge part of a mirror unit, sectional drawing, the side view before mirror angle adjustment, and the side view after mirror angle adjustment. It is an internal top view which abbreviate | omitted the traveling body drive mechanism of the image reading apparatus. It is an internal top view which abbreviate | omitted the traveling body drive mechanism of the image reading apparatus which concerns on a modification. It is a front view of the modification of the running body of an image reading device. FIG. 6 is a side view of the scanner frame portion of the image reading apparatus on the sub-scanning end side. It is a front view of the rod hole which supports the guide rod edge part of the scanner frame part of an image reading apparatus. It is a side view of a guide rod. It is a side view of the adjustment member for height adjustment of a guide rod. FIG. 6 is a side view of a state in which an adjustment member is overlaid on a rod hole of a scanner frame portion of the image reading apparatus. It is a side view similar to FIG. 20A, and is a side view when starting adjustment of the adjustment member. FIG. 20B is a side view similar to FIG. 20A, wherein the adjustment member is being adjusted. It is a side view of the modification of an adjustment member. It is a modification of the scanner frame part of an image reading apparatus, Comprising: It is a side view at the subscanning end side. FIG. 23 is a side view of the modification of FIG. 22 with the adjustment member and the intermediate member on the sub-scanning end side removed. It is a side view of the intermediate member used for the modification of FIG. It is a front view of the rod hole which lets the guide rod edge part of an intermediate member pass. It is a side view of the adjustment member attached to an intermediate member. In the modification of FIG. 22, it is a side view of the state which attached only the intermediate member to the side surface by the side of the subscanning end. FIG. 14B is a side view of the lower guide rod of FIG. 14B. FIG. 14B is a side view of the upper guide rod of FIG. 14B. It is a side view at the time of starting adjustment of the adjustment member attached to the intermediate member. It is a side view in the middle of adjustment of the adjustment member attached to the intermediate member. It is a side view of the modification of the sub-scanning start side of the scanner frame part of an image reading device. It is a side view of the modification of the adjustment member attached to the side surface of the scanner frame part of FIG. (A) and (b) are the side views of the guide rod attached to the scanner frame part of FIG. FIG. 31 is a side view of a state in which two types of adjustment members are attached to the side surface of the scanner frame portion of FIG. 30. It is sectional drawing which shows another example of arrangement | positioning of a light source and a light-guide plate with respect to the board | substrate of a traveling body. It is the front view seen from the sub-scanning direction of the board | substrate of FIG. It is a figure which shows the relationship between the light quantity distribution of the reading range of a document, and the optical axis of a 1st mirror. It is a whole schematic side view of an image reading apparatus having a differential type traveling body of a conventional reduction optical system. It is a principal part schematic side view of the image reading apparatus which has the integrated traveling body of the conventional reduction optical system.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Image forming device)
As shown in FIG. 1, the image forming apparatus 100 includes an image forming unit 101, a paper supply device 40, and an image reading unit 104. The image reading unit 104 includes an image reading device 102 fixed on the image forming unit 101, and an ADF (Auto Document Feeder) 103 as a document conveying device supported by the image reading device 102.

  The paper supply device 40 has two paper feed cassettes 42 arranged in multiple stages in the paper bank 41, a feed roller 43 that feeds paper as a recording medium from the paper feed cassette 42, and separates and feeds the fed paper. A separation roller 45 supplied to the path 44 is included. In addition, the image forming apparatus 100 includes a plurality of transport rollers 46 that transport the paper to the paper feed path 37. The paper in the paper feed cassette 42 is fed to the paper feed path 37 in the image forming apparatus 100.

  The image forming unit 101 includes an optical writing device 2, a transfer unit 24 having four process units 3K, 3Y, 3M, and 3C for forming toner images of K, Y, M, and C colors, an intermediate transfer belt 25, and paper A transport unit 28, a timing roller pair 33, a fixing device 34, a paper discharge roller pair 35, a switchback device 36, a paper feed path 37, and the like are provided.

  Then, a light source such as a laser diode or LED (not shown) disposed in the optical writing device 2 is driven, and laser is directed toward the photosensitive members 4K, 4Y, 4M, and 4C of the process units 3K, 3Y, 3M, and 3C. Irradiate light L.

  By irradiation with the laser light L, an electrostatic latent image is formed on the surface of the drum-shaped photoconductors 4K, 4Y, 4M, and 4C, and the electrostatic latent image is developed into a toner image through a predetermined development process. Is done. Subscripts of K, Y, M, and C after the symbol indicate that the specifications are for black, yellow, magenta, and cyan.

  In the image forming apparatus 100 having the above-described configuration, the toner images formed on the surfaces of the photoconductors 4K, 4Y, 4M, and 4C are sequentially superimposed on the intermediate transfer belt 25 that moves endlessly in the clockwise direction in FIG. Is done.

  By this primary transfer, a four-color superimposed color toner image is formed on the intermediate transfer belt 25. The paper supplied from the paper supply device 40 is sent to the secondary transfer nip formed between the paper transport unit 28 and the intermediate transfer belt 25 by the timing roller pair 33 at a predetermined timing, and the intermediate transfer belt. The color toner image on the image 25 is secondarily transferred onto the paper at once.

  The sheet that has passed through the secondary transfer nip is separated from the intermediate transfer belt 25 and conveyed to the fixing device 34. The sheet conveyed to the fixing device 34 is fixed to the full color image by pressure or heating in the fixing device 34, then sent from the fixing device 34 to the paper discharge roller pair 35, and then discharged outside the apparatus. . The image forming unit 101 is not limited to the configuration shown in FIG. 1, and may be a configuration such as an inkjet recording method.

(Image reading device)
As shown in FIGS. 2A and 2B, the image reading device 102 disposed on the image forming unit 101 includes a scanner frame portion 102a as a housing that forms the side surface and the lower surface of the image reading device 102, and the scanner frame. A scanner cover portion 102b attached to the upper opening of the portion 102a.

  The scanner cover portion 102b of the image reading apparatus 102 constitutes the upper surface of the image reading apparatus 102, and includes an original platen glass 110 on which an original is placed and a belt-like flow reading glass 111 through which the original passes when the ADF is used.

  Inside the scanner frame portion 102a of the image reading apparatus 102, a traveling body 112 and guide rods 113 and 114 parallel to each other are provided as guide members for guiding the traveling body 112 in the sub-scanning direction. Then, an original is placed on the original platen glass 110 of the scanner cover 102b, and the original is read by moving the traveling body 112 in the sub-scanning direction (arrow A direction) immediately below the original platen glass 110.

(Basic structure of image reader)
As shown in FIG. 3, the traveling body 112 has a light source 115 for exposing the reading range of the document in the main scanning direction, and a plurality of mirrors that sequentially reflects reflected light from the reading range of the document and guides it to the reading unit. The first mirror 120a, the second mirror 120b, the third mirror 120c, the fourth mirror 120d, the fifth mirror 120e as the reflecting means 120, and the reflected light reflected by the reflecting means 120 are imaged and guided to the reading means. An imaging lens 121 and an image sensor 122 as reading means for reading reflected light from the reading range of the original are mounted.

  Only the first mirror 120a is mounted on the traveling body 112, but the other four mirrors 120b to 120e are arranged on a pair of side plates 102a1 and 102a2 facing the sub-scanning direction of the scanner frame portion 102a.

  Since the conventional integrated image reading apparatus has all the mirrors mounted on the traveling body, a vibration isolating member is provided on each mirror in order to prevent image quality degradation such as dot displacement due to the vibration of the traveling body being transmitted to the mirror. It was necessary to install. However, in this embodiment, since only the first mirror 120a is mounted on the traveling body 112, it is only necessary to attach a vibration isolating member only to the first mirror 120a.

  Since the other second to fifth mirrors 120b to 120e are fixedly arranged on the side plates 102a1 and 102a2 of the scanner frame portion 102a, it is not necessary to attach a vibration isolating member. For this reason, the vibration isolator for the second to fifth mirrors 120b to 120e can be omitted, and the number of parts, the number of assembly steps, and the manufacturing cost can be reduced.

  Specifically, the arrangement of each of the mirrors 120a to 120e is such that the first mirror 120a is disposed at the rear end of the traveling body 112 (the left end of the traveling body 112 in FIG. 3), and is inclined at 45 ° with respect to the sub-scanning direction As a result, the reflected light from the document placed on the document table glass 110 or the document passing over the flow-reading glass 111 is reflected backward (left side in FIG. 3, that is, opposite to the sub-scanning direction). I have to.

  The second mirror 120b is disposed at the same height as the first mirror 120a inside the left side plate 102a1 opposite to the sub-scanning direction with respect to the first mirror 120a, and is inclined at 45 ° with respect to the sub-scanning direction. ing.

  The third mirror 120c is disposed inside the left side plate 102a1 vertically below the second mirror 120b, and is inclined at 45 ° in the direction opposite to the second mirror 120b with respect to the sub-scanning direction. .

  Accordingly, the second mirror 120b and the third mirror 120c constitute a first roof mirror.

  The fourth mirror 120d is disposed inside the right side plate 102a2 in the sub-scanning direction with respect to the third mirror 120c, and is inclined at 45 ° with respect to the sub-scanning direction, like the second mirror 120b.

  The fifth mirror 120e is arranged inside the right side plate 102a2 vertically above the fourth mirror 120d, and is inclined at 45 ° with respect to the sub-scanning direction, like the third mirror 120c.

Accordingly, the fourth roof 120d and the fifth mirror 120e constitute a second roof mirror. The first roof mirror and the second roof mirror are optically equivalent, and a common roof mirror can be used, but as shown in FIG. 4A, the second roof mirror (the fourth mirror 120d and the fifth mirror 120e). Can be shorter than the first roof mirror (second mirror 120b and third mirror 120c) in the main scanning direction.
The first to fifth mirrors 120a to 120e can be arranged so that the angle can be adjusted in order to ensure geometric accuracy.

  The light reflected by the fifth mirror 120 e travels backward in the sub-scanning direction toward the traveling body 112 and is imaged on the image sensor 122 by the imaging lens 121. Then, the original image is read by the image sensor 122, and the read original image is subjected to signal processing by an image processing unit and an electronic sort unit (not shown) and supplied to the optical writing device 2 in FIG.

  Further, when the image of the document conveyed by the ADF 103 in FIG. 1 is read by the image sensor 122 of the traveling body 112, the traveling body 112 is slightly left of the position A in FIG. 1 (the flow scanning in FIGS. 2A, 2B, and 3). (Just below the glass 111). With the traveling body 112 stopped at this position, when the document conveyed by the ADF 103 passes over the flow reading glass 111, the image sensor 122 sequentially reflects the light emitted from the light source 115 on the document surface. Read the original image.

In FIG. 3, the optical path length (conjugate length) of the reflected light reflected from the document is expressed as follows, where L1 is the conjugate length at the document reading start position.
L1 = a + b + c + d + e + f
Here, a: the distance from the original surface to the first mirror 501, b: the distance from the first mirror to the second mirror, c: the distance from the second mirror to the third mirror, d: the distance from the third mirror to the fourth mirror, e: distance from the fourth mirror to the fifth mirror, f: distance from the fifth mirror to the image sensor 122

In FIG. 3, when the amount of movement of the traveling body 112 in the sub-scanning direction is α, the conjugate length L2 after the traveling body 112 has advanced by α is expressed as follows.
L2 = a + (b + α) + c + d + e + (f−α) = a + b + c + d + e + f
Thus, even if the traveling body 112 moves in the sub-scanning direction α, it can be seen that L1 = L2 before and after the movement and the conjugate length does not change.

  In the conventional integrated scanning optical unit, in order to secure the conjugate length, the conjugate length is secured by arranging a number of mirrors in a single traveling body and folding the optical path. However, the number of mirrors mounted and the folded optical path Due to this span, the size of the traveling body increases in the height direction and the sub-scanning direction.

  In this embodiment, since only a specific mirror is mounted on the traveling body 112 as a reflecting means and the other mirrors are arranged outside the traveling body 112, the size (height and sub-directions) of the traveling body 112 is arranged. (Scanning direction) does not increase, and the weight of the traveling body 112 does not become excessive.

  On the other hand, by disposing at least two of the mirrors arranged outside the traveling body at both ends in the sub-scanning direction, the optical path length can be easily increased while keeping the conjugate length constant. When the optical path length is increased, a long-focus imaging lens can be used, which is advantageous in realizing a reading apparatus that narrows the angle of view and is less affected by performance degradation due to component processing errors.

  In FIG. 3, either the third mirror 120c or the fourth mirror 120d is omitted, and the reflected light is directly guided from the second mirror to the fourth mirror 120d, or directly from the third mirror 120c to the fifth mirror 120e. A configuration for guiding reflected light is also possible.

  When the third mirror 120c and the fourth mirror 120d are used, there is an advantage that the optical path lengths c and e in the vertical direction can be earned on both the left and right sides in FIG.

  As described above, the number of mirrors of the integrated scanning optical unit is reduced, and the mirrors are disposed at both ends outside the traveling body 112, thereby reducing the size of the traveling body 112 in the height direction and the sub-scanning direction. Can be reduced in size and thickness.

(Specific configuration of image reading apparatus)
Hereinafter, a specific configuration of the image reading apparatus, which is a main part of the embodiment of the present invention, will be described.
As shown in FIGS. 4A and 4B, two guide rods 113 and 114 extending in the sub-scanning direction are arranged in parallel in the scanner frame portion 102a. These two guide rods 113 and 114 are for guiding the traveling body 112 shown in FIGS. 5 and 6 to move in the sub-scanning direction. At both ends of the traveling body 112, as shown in FIG. Two rod holes 112a and 112b are formed. Two guide rods 113 and 114 are slidably inserted into the two rod holes 112a and 112b. The guide rods 113 and 114 are disposed as close as possible to the inside of the left and right side plates 102a1 and 102a2 of the scanner frame portion 102a.

  Between one guide rod 114 and the side plate 102a3 (upper side in FIG. 4A), a pair of left and right pulleys 125 and 126 are arranged in the sub-scanning direction. In FIG. 4A, the right side is the drive pulley 126 and the left side is the driven pulley 125. A timing belt 127 is stretched between the pulleys 125 and 126. A motor 128 is disposed outside the side plate 102a3, and a motor gear 129 is attached to the shaft of the motor 128. A drive gear 130 is disposed coaxially with the drive pulley 126, and a timing belt 131 is stretched between the drive gear 130 and the motor gear 129.

  As the motor 128 rotates, the driving pulley 126 rotates via the motor gear 129, the timing belt 131, and the driving gear 130. As a result, the timing belt 127 stretched between the two pulleys 125 and 126 rotates, and the traveling body 112 moves in the sub-scanning direction. The moving direction of the traveling body 112 can be switched by reversing the rotation direction of the motor 128. In this embodiment, since it is easy to reduce the weight of the traveling body 112 by reducing the number of mounted mirrors, the one-side drive of the traveling body 112 can be facilitated as described above.

  The traveling body 112 has a traveling body frame 135 extending in the main scanning direction as shown in FIGS. The traveling body 112 frame 135 is made of sheet metal in which a horizontal plate portion 135a and a vertical plate portion 135b are integrally formed, and the horizontal plate portion 135a is extended to the sub-scanning direction side of the center portion in the width direction of the traveling body 112 frame 135. Thus, a support plate 136 extending in the sub-scanning direction is attached.

  On the support plate 136, an imaging lens 121 having an optical axis directed in the sub-scanning direction is mounted. The imaging lens 121 is positioned by mounting a lens band 137 formed from above with a leaf spring and fixing both ends of the lens band 137 to the support plate 136 with screws 138. In this manner, by incorporating the imaging lens 121 into the traveling body 112, it is possible to reduce the number of parts and the number of assembly steps.

  As shown in FIG. 5, the substrate 141 perpendicular to the sub-scanning direction of the traveling body 112 is fixed to the left side surface of the vertical plate portion 135 b of the traveling body 112 frame by a pair of screws 142 at both ends. The substrate 141 continuously extends in the main scanning direction of the traveling body 112. In FIG. 5, the imaging lens 121 and the optical axis are arranged on the right side, that is, approximately at the center in the height direction of the first mounting surface on the imaging lens 121 side. An image sensor 122 having a CCD is mounted so as to match. A hole 135c of a predetermined size is formed in the vertical plate portion 135b of the traveling body frame 135 so that the image sensor 122 can protrude in the sub-scanning direction.

  A bracket 145 having substantially the same length in the width direction as the traveling body frame 135 is attached to the horizontal plate portion 135a of the traveling body frame 135 with a pair of screws 146 at both ends. The bracket 145 is for attaching the light guide plate 150 and the first mirror 120a, and has a base portion 145a fixed by a screw 146 and a support portion 145b rising vertically from the vicinity of the base portion 145a. A cutout hole 147 for fitting both ends of the light guide plate 150 and a cutout hole 148 for fitting both ends of the first mirror 120a are formed in the support portion 145b.

  In FIG. 5, a plurality of elements arranged at equal intervals in the main scanning direction at positions shifted slightly above the center in the height direction of the substrate 141 on the second mounting surface on the left side of the substrate 141, that is, on the opposite side to the image sensor 122. A light source 115 made up of LEDs is mounted. The LED is configured as a top view type, and a light guide plate 150 is disposed on the light emitting surface 115a side. The top view type refers to a type in which a light source mounted on a substrate emits light in a direction perpendicular to the mounting surface of the substrate. That is, LED light is emitted in a direction perpendicular to the mounting surface of the substrate 141 (the direction opposite to the sub-scanning direction), and this light is incident on the incident surface of the light guide plate 150 perpendicularly.

  When the light source 115 is arranged on the first mounting surface of the substrate 141 on the side where the imaging lens 121 is present, the light source 115 is arranged on the imaging lens 121 so as not to block the optical path from the imaging lens 121 to the image sensor 122. It is necessary to displace the outer diameter (outside) from the outer diameter. However, if this is done, the height dimension of the image reading apparatus 102 will increase accordingly. By arranging the light source 115 on the side opposite to the imaging lens 121 and the image sensor 122, the light source 115 can be arranged within the range of the outer diameter of the imaging lens 121. The outer diameter of the lens 121 can be made approximately the same.

  Further, by mounting the light source 115 and the image sensor 122 back to back on the front and back surfaces of the same substrate 141, the number of assembly parts can be reduced, and the cost can be reduced.

  The light guide plate 150 efficiently guides the light of the LED as the light source 115 to the original. The cross-sectional shape is inscribed (partially) into a rectangle having a length to width ratio (referred to as a rectangular ratio) of 1 or more. It forms a polygonal shape (including matching). Such a light guide plate 150 is disclosed, for example, in JP-A-2006-67551. Both ends of the light guide plate 150 are supported in a state of being fitted into the notch holes 147 of the both end support portions 145b of the bracket 145. In order to prevent misalignment of both ends of the light guide plate 150, a sheet metal clip can be arranged inside the notch hole 147. For such a clip, for example, a leaf spring 174 as shown in FIG. 13B can be used.

  The optical axis of the light guide plate 150 is inclined at a predetermined angle with respect to the document surface, the upper and lower side surfaces are reflecting surfaces, and the light emitting surface 115 a of the LED is in close contact with the right incident surface 150 a of the light guide plate 150. Then, a high light amount portion of a composite curve of the light amount distribution by direct light from the radiation surface 150b facing the original surface and reflected light from a reflection surface (a main reflection surface or an auxiliary reflection surface) (not shown) arranged in the surrounding area is obtained. A reading area is set as the maximum reading width.

  On the traveling body frame 135 on the left side of the substrate 141, the first mirror 120a is disposed at an inclination angle of 45 ° below and behind the light guide plate 150. The first mirror 120a extends in the main scanning direction, and both ends thereof are supported in a state of being fitted into a notch hole 148 formed in the support portion 145b of the bracket 145 of the traveling body 112. The reflected light of the light incident on the first mirror 120a from directly above the first mirror 120a is reflected by the first mirror 120a at a right angle in the direction opposite to the sub-scanning direction (horizontal direction). Yes.

  In order to prevent the vibration of the traveling body 112 from being transmitted to both ends of the first mirror 120a and to prevent displacement, a sheet metal clip can be disposed inside the notch hole 148. For such a clip, for example, a leaf spring 174 as shown in FIG. 13B can be used.

  In this embodiment, the light source 115, the light guide plate 150, and the first mirror 120a by LEDs are arranged within the outer diameter range of the imaging lens 121, so that the vertical height of the traveling body 112 is set to the imaging lens. The outer diameter of 121 can be approximately the same.

The vertical height H of the image reading apparatus 102 including the traveling body 112 can be expressed as H = L + M / √2 + N + O + P + Q.
L: outer diameter of lens 403 M: width of third mirror 120c and fourth mirror 120d N: gap between upper end of traveling body 112 and lower surface of document table glass 110 O: third mirror 120c, fourth mirror 120d And the bottom plate of the scanner frame portion 102a P: thickness of the bottom plate of the scanner frame portion 102a Q: thickness of the platen glass 110

  Here, the sizes of L, M, N, O, P, and Q are naturally determined, but the effective reflection surfaces are not changed to the lower end portions of the third mirror 120c and the fourth mirror 120d inclined at 45 °. By forming a horizontal C surface (chamfered surface) in the range, the height (M / √2) of the third mirror 120c and the fourth mirror 120d can be reduced, so that the height H of the image reading device can be reduced. .

(Mounting structure of mirror as reflection means)
As shown in FIGS. 7 and 8, two side plates 102a1 and 102a2 facing each other in the sub-scanning direction of the scanner frame portion 102a have two upper and lower mirror insertion holes 155 and 156 and a pair of left and right mounting holes 160. Is formed. A mirror mounting member 161 shown in FIG. 9 is fixed to the mounting hole 160 with an adjusting screw 162.

  The mirror mounting member 161 is arranged in a pair of left and right as shown in FIG. 7, and the second mirror 120b and the third mirror 120c are attached to the mirror mounting member 161 on the sub-scanning start side (back side) in FIG. Configure the unit. The second mirror unit is configured by attaching the fourth mirror 120d and the fifth mirror 120e to the mirror attachment member 161 on the sub-scanning end side (near side).

  As shown in FIG. 10, the mounting hole 160 is traversed in the vertical direction in the outer surface of the side plates 102 a 1 and 102 a 2 of the scanner frame 102 a and facing the main body 161 b of the mirror mounting member 161. In addition, a scale 165 for position adjustment is provided. The scale 165 is provided in increments of 1 mm in the vertical direction, for example, so that the height positions of the first mirror unit and the second mirror unit can be visually recognized from the screw insertion hole 161c of the mirror mounting member 161. Yes.

  That is, the height position of the mirror unit can be known by reading the scale 165 that matches the upper end or the lower end of the screw insertion hole 161c. Therefore, the operator can adjust the height positions of the first mirror unit and the second mirror unit easily and accurately while looking at the scale 165.

  The mirror mounting member 161 is formed by bending a longitudinal end of a rectangular sheet metal at a right angle to form a pair of support portions 161a. A mirror unit is configured by attaching two mirrors. As shown in FIG. 9, two positioning holes 163 and 164 for fitting the end portions of the respective mirrors into the support portion 161 a are formed vertically, and a horizontal cut 161 d is formed between the positioning holes 163 and 164. Has been.

  The notch 161d is for receiving the partition plate portion 157 between the upper and lower two-stage mirror insertion holes 155 and 156 when the mirror mounting member 161 is attached to the side plates 102a1 and 102a2.

  The shape of the positioning holes 163 and 164 substantially corresponds to the cross-sectional shape of the mirror. However, the shape of the positioning holes 163 and 164 is slightly larger than the cross-sectional shape of the mirror so that the mirror can slightly swing inside the positioning holes 163 and 164. It's getting bigger. In this embodiment, the upper positioning hole 163 has a rectangular shape corresponding to the cross-sectional shapes of the second mirror 120b and the fifth mirror 120e. A semicircular arc-shaped fulcrum part 175 is formed on the lower inner edge of the positioning hole 163 and abuts on the side surface of the mirror to be a rocking fulcrum.

  The lower positioning hole 164 forms an acute corner 164a by horizontally cutting out the lower part thereof. This is because the lower edges of the third mirror 120c and the fourth mirror 120d are chamfered to form a tapered surface T.

  By forming the tapered surface T, the height direction of the mirrors 120c and 120d can be shortened while maintaining the effective reflection surface on the upper surface of the mirrors 120c and 120d, and the vertical space of the reading device can be shortened. it can. A semicircular arc-shaped fulcrum portion 175 is also formed on the inner edge on the upper side of the positioning hole 164 so as to come into contact with the side surface of the mirror and serve as a fulcrum.

  As shown in FIGS. 11 to 13, cut-and-raised protrusions 170 and 171 are formed at the edges of the positioning holes 163 and 164 of the support portion 161 a of the mirror mounting member 161. A female screw hole 172 is formed in the protrusions 170 and 171. The side surfaces of the mirrors 120b to 120e can be pressurized with the tip of the adjusting screw 173 screwed into the female screw hole 172.

  Inside the positioning holes 163 and 164, as shown in FIGS. 13A to 13D, a plate spring 174 having a V-shaped cross section is provided as an elastic member. The leaf spring 174 is disposed on the side opposite to the adjustment screw 173, and elastically supports the side surfaces of the mirrors 120b to 120e opposite to the pressure side by the adjustment screw 173. Then, by adjusting the tightening amount of the adjusting screw 173, the tilt angle of the mirror around the fulcrum 175 can be adjusted.

  The leaf spring 174 has bent portions 174a and 174b at both ends, and applies one bent portion 174a to the end of the mirror. The leaf spring 174 is prevented from falling off from the support portion 161a by hooking a cut and raised protrusion 174d formed between the other bent portion 174b and the V-shaped bend portion 174c inside the support portion 161a.

  FIGS. 13C and 13D show changes in the inclination of the mirror 120b before and after the adjustment screw 173 is tightened. By tightening the adjustment screw 173, the mirror 120b rotates clockwise about the fulcrum portion 175. When the adjustment screw 173 is loosened, the mirror 120b rotates counterclockwise about the fulcrum 175. The same applies to the other mirrors 120c to 120e.

  The angle adjustment of each mirror 120b-120e is basically adjusted to the same amount at both ends thereof. In order to facilitate the adjustment of the equal amount, a scale or a mark for confirming the rotation operation amount of the adjustment screw 173 can be attached to the adjustment screw 173 or the cut and raised protrusion 170 as necessary.

(Guide rod mounting structure)
As shown in FIG. 14A, two (four in total) adjustment members 180 are attached to the outer surfaces of the pair of side plates 102a1 and 102a2 in the sub-scanning direction of the box-shaped scanner frame portion 102a. These adjusting members 180 are for supporting both ends of the two guide rods 113 and 114 so that the height can be adjusted, and are formed into a horizontally long rectangular shape shown in FIG. 19 by sheet metal. The mirror mounting structure is not shown in FIG. In the embodiments after FIG. 14, a structure other than the structure shown in FIG. 7 or 8 can be adopted as the mirror mounting structure.

  It is ideal that all the ends of the two guide rods 113 and 114 are supported to be height-adjustable, but depending on the case, one, two, or three of the guide rods 113 and 114 may be used. It is also possible to use one, two or three adjustment members 180 to support the two ends in a height-adjustable manner.

  In FIG. 6, the guide rods 113 and 114 are slidably inserted into the rod holes 112a and 112b at the left and right ends of the traveling body 112. However, the guide rods 113 and 114 facilitate the removal of the traveling body 112 from the scanner frame portion 102a for maintenance or the like. Therefore, a support structure as shown in FIG. 15 can be obtained.

  In the support structure of FIG. 15, one guide rod 113 is slidably inserted into a rod hole 190 a of a support portion 190 disposed at a lower portion of one end of the traveling body 112. The slider plate 191 disposed at the lower end is slidably brought into contact with the lower surface. Thereby, when taking out traveling body 112, only one guide rod 113 can be pulled out from traveling body 112, and the other guide rod 114 can be left as it is.

  14B is more convenient than the scanner frame portion 102a of FIG. 14A to facilitate the pulling out of the guide rod 113, and FIGS. 23 to 29 illustrate this. Will be described later with reference to FIG.

  When the traveling body 112 is slidably supported by the slider plate 191 on one side as shown in FIG. 15, the traveling body 112 is driven on both sides, or the driving system is disposed on the side where the support portion 190 is disposed. Good.

  If the accuracy of attaching the end portions of the guide rods 113 and 114 to the side plates 102a1 and 102a2 of the scanner frame portion 102a is not good, an error occurs in the movement of the traveling body 112 in the sub-scanning direction, and the geometric accuracy is lowered. This geometric accuracy is particularly affected by the height of the guide rods 113 and 114. Therefore, the height position of the guide rods 113 and 114 is adjusted by the adjusting member 180.

  Specifically, screw holes 194 and 195, a rod hole 196 having the shape shown in FIG. 17, and an adjustment hole 197 are provided in the right side plate 102a2 of the scanner frame portion 102a as shown in FIG. These four holes 194 to 197 are symmetrically arranged in FIG. 16, and four holes 194 to 197 are used for one adjusting member 180. The plurality of hole shapes are exactly the same on the left side plate 102a1 on the opposite side of the scanner frame portion 102a. In addition, the rectangular dotted line in FIG.

  The rod hole 196 in FIG. 17 is for inserting both ends of the guide rods 113 and 114 shown in FIG. The two guide rods 113 and 114 have exactly the same shape, and will be described below with the guide rod 113 as the center.

  The rod hole 196 includes a circular portion 196a that is slightly larger than the outer diameter of the main body portion 113a of the guide rod 113, and a long hole portion 196b that is narrower than the circular portion 196a. The elongated hole portion 196b is for fitting the annular groove 113b of the guide rod 113 to the left and right edges thereof to restrain the axial movement of the guide rod 113.

  The guide rod 113 has annular grooves 113b and 113c at both ends thereof. One annular groove 113b is formed corresponding to the total value of the plate thicknesses so that the side plate 102a2 and the adjustment member 180 can be received in an overlapped state.

  The other annular groove 113c is formed to be slightly wider than the annular groove 113b in consideration of variations in processing accuracy of parts. The adjusting member 180 having the shape shown in FIG. 19 is screwed to the screw holes 194 and 195 of the left and right side plates 102a1 and 102a2 of the scanner frame portion 102a with two screws 198 and 199 as shown in FIG. 20B.

  The adjustment member 180 has a rod hole 181 composed of a circular portion 181a and a long hole portion 181b having the same size as the rod hole 196 in FIG. 17, but the direction of the hole is different from that in FIG. In FIG. 17, the long hole portion 196b is in the vertical direction, whereas in FIG. 19, the long hole portion 181b is in the horizontal direction. Thus, the long hole 196b and the long hole 181b form a right angle between the rod hole 196 of the side plate 102a2 and the rod hole 181 of the adjustment member 180.

  Further, the adjustment member 180 has a screw hole 182 for screwing into the screw hole 194 of the side plate 102a2 of the scanner frame portion 102a and an arc for screwing into another screw hole 195 so as to sandwich the rod hole 181 from the left and right directions. A hole 183 is provided. The screw hole 182 constitutes a first end portion of the adjustment member 180, and the arc hole 183 constitutes a second end portion. The arc hole 183 has an arc-shaped edge centered on the screw hole 182. A rectangular adjustment notch 184 is formed at the right end of the adjustment member 180.

  Two such adjustment members 180 are attached to the left and right side plates 102a1 and 102a2 of the scanner frame portion 102a. 20A and 20B show a state in which the adjustment member 180 is attached to the side plates 102a1 and 102a2. 20A shows a state before the screws 198 and 199 are attached, and FIG. 20B shows a state after the screws 198 and 199 are attached.

  In the state where the adjustment member 180 is loosely tightened with screws 198 and 199 as shown in FIG. 20B, the cross-shaped gap C formed by the overlap of the adjustment hole 197 and the adjustment notch 184 is like the tip shape of a minus driver. The jig 200 is inserted, and the jig 200 is rotated clockwise or counterclockwise. Then, the adjusting member 180 swings upward or downward around the screw 198 as a fulcrum, and the height of the elongated hole 181b changes.

  Accordingly, the heights of the end portions of the guide rods 113 and 114 inserted into the long hole portion 181b change together with the long hole portion 181b. FIG. 20C shows an adjustment example in which the end of the guide rod 113 is raised by a distance H.

  The same applies when adjusting the other guide rods 114. When the position of the adjustment member 180 is adjusted by a required amount, the adjustment operation is completed by pulling out the jig 200 and finally tightening the screws 198 and 199. When the screws 198 and 199 are tightened, the screw 199 of the arc hole 183 is tightened from the screw 199, and the screw 198 on the opposite side serving as a rotation fulcrum is finally tightened. If the tightening of the screws 198 and 199 is reversed, the adjusting member 180 may rotate unexpectedly.

  In this way, by supporting the ends of the guide rods 113 and 114 between the screw 198 serving as the fulcrum and the jig 200, the end of the adjustment member 180 by the jig 200 can be moved in the vertical direction according to the lever principle. The amount of movement of the long hole portion 181b can be less than the amount of movement, and the precise height adjustment of the ends of the guide rods 113 and 114 is possible.

  The adjusting member 180 is not a method of adjusting the height by rotating as described above, but by using the adjusting member 186 having the shape shown in FIG. 21 and translating the entire adjusting member 186 in the height direction, the guide rod You may make it perform the height adjustment of the edge part of 113,114.

  In this case, without using the jig 200, a pair of left and right screws (not shown) to be screwed into the screw holes 194 and 195 are once loosened, and the adjustment member 186 is moved to the left and right vertically elongated holes (first end) 187. A temporarily tightened state is set so that it can move up and down along the vertically elongated hole (second end) 188. In this way, the adjustment member 186 is moved to a necessary height, and the screw is tightened again to complete the adjustment work.

(Modification of guide rod mounting structure)
Next, when the traveling body 112 shown in FIG. 15 is taken out from the scanner frame portion 102a, a modification in which only one guide rod 113 is pulled out from the traveling body 112 and the other guide rod 114 is left as it is is shown in FIGS. This will be described with reference to FIG.

  FIG. 23 shows the right side plate 102a2 of the scanner frame portion 102a of FIG. 14B. A cutout hole 206 for attaching the intermediate member 205 formed of the sheet metal of FIG. 24 is formed in the right side plate 102a2. A reference pin 207 and a screw hole 208 are arranged on the left and right of the notch hole 206.

  Other portions are the same as those of the left and right side plates 102a1 and 102a2 of the scanner frame portion 102a of FIGS. 14A and 16. The intermediate member 205 is for facilitating the work when the guide rod 113 is removed from the scanner frame portion 102a and reattached, and the work time is shortened.

  That is, as shown in FIG. 15, the traveling body 112 has only the slider plate 191 disposed at the lower part of one end thereof placed on the guide rod 114, but on the opposite side, the guide rod 113 is inserted into the rod hole 190 a of the support portion 190. Has been inserted. For this reason, if the traveling body 112 is to be removed from the scanner frame portion 102a for maintenance or the like, the guide rod 113 must be pulled out from the rod hole 190a.

  In the scanner frame portion 102a of FIG. 14A, the end portions of the two guide rods 113 and 114 are respectively supported by the elongated hole portions 180b of the adjustment member 180. Therefore, when the traveling body 112 is taken out from the scanner frame portion 102a, the travel is performed. The guide rod 113 on the side inserted into the body 112 must be removed from the side plates 102a1 and 102a2 of the scanner frame portion 102a. Since the guide rod 114 on the slide side only has the slider plate 191 at the end of the traveling body 112 mounted thereon, it is not necessary to remove it from the side plates 102a1 and 102a2.

  When removing the guide rod 113, the screws 198 and 199 of the adjustment member 180 are removed, and the adjustment member 180 is removed from the side plates 102a1 and 102a2. Then, when the guide rod 113 is attached to the side plates 102a1 and 102a2 of the scanner frame portion 102a again, it is necessary to adjust the height of the guide rod 113 by the adjusting member 180 again. Then it takes a long time to work and it is not convenient.

  Therefore, in this embodiment, in order to attach the intermediate member 205 to the side plate 102a2 of the scanner frame portion 102a, as shown in FIG. 24, the intermediate member 205 has left and right screw holes 210 and 211, a left laterally long reference hole 212, and a right side. The circular reference hole 213 is formed. Further, the same holes (rod hole 214, adjustment hole 215, screw holes 216, 217) as the side plate 102a2 of the scanner frame portion 102a of FIG. 16 are formed inside these holes 210-213. The intermediate member 205 is attached to the notch hole 206 of the side plate 102a2.

  At this time, the pair of reference pins 207 of the side plate 102 a 2 enters the reference holes 212 and 213 of the intermediate member 205, and the right reference pin 207 serves as a positioning reference in the vertical and horizontal directions of the right end portion of the intermediate member 205. The left reference pin restricts the rotation of the intermediate member 205 around the right reference pin 213. Both of the reference holes 212 and 213 are preferably set so that the tolerance between the reference holes 212 and 213 and the reference pin 207 is minimized so that a large gap is not formed between the reference pins 207.

  The rod hole 214 has a shape as shown in FIG. 25, and has a circular portion 214a and a long hole portion 214b. This shape is the same as FIG. 26 is attached to the intermediate member 205 in the same manner as described in FIGS. 20A to 20C.

  That is, in this modification, the intermediate member 205 is substituted for the side plate 102a2 of the scanner frame portion 102a. FIG. 27 shows a state in which the intermediate member 205 is attached to the cutout hole 206 of the side plate 102a2 of the scanner frame portion 102a with two screws 222 on the left and right.

  28A and 28B show guide rods 113 and 114 attached to the scanner frame portion 102a of FIG. 14B. The guide rod 113 in FIG. 28A is a guide rod 113 disposed on the lower side of FIG. 14B. The guide rod 113 is inserted into the traveling body 112, and is formed with a narrow-diameter portion 113d having a diameter smaller than that of the main body 113a at one end, and an annular groove 113e having a width into which the adjustment member 180a and the intermediate member 205 are inserted at the other end. Is formed.

  The thickness of the small diameter portion 113d is made the same as the groove diameter of the annular groove 113e. As a result, the elongated hole 196b of the rod hole 196 formed in the side plate 102a1 of the scanner frame 102a and the rectangular hole formed by overlapping the elongated hole 181b of the adjustment member 180 that overlaps the elongated hole 196b are narrowly formed. The diameter portion 113d is supported so as to be pulled out with almost no gap.

  In addition, the adjustment member 180 is not provided on the side plate 102a1 of the scanner frame 102a, and a rod hole capable of positioning the small-diameter portion 113d is formed directly on the side plate 102a1 of the scanner frame 102a. The small diameter portion 113d may be fitted.

  FIG. 28B is a guide rod 114 arranged on the upper side of FIG. 14B for supporting the slider plate 191. The guide rod 114 has the same shape as that of FIG. 18, and an annular groove 114b that can be received in a state where the side plate 102a2 and the adjustment member 180 are overlapped is formed at one end of the main body 114a, and the annular groove 114b is formed on the opposite side. A slightly wider annular groove 114c is formed.

  FIGS. 29A and 29B show a state in which the adjustment member 180a attached to the intermediate member 205 is adjusted. This is the same as the adjustment of the adjustment member 180 in FIGS. 20B and 20C, and a description thereof will be omitted.

  As described above, when the intermediate member 205 is used, the adjustment member 180a attached to the intermediate member 205 is left as it is, and only the screw 222 attaching the intermediate member 205 to the side plate 102a2 is removed. Accordingly, the guide rod 113 can be pulled out from the scanner frame portion 102a in the right direction in FIG. 14B while the end portion of the guide rod 113 is supported by the adjustment member 180a and the intermediate member 205.

  As shown in FIG. 28A, the left end portion of the guide rod 113 is a narrow-diameter portion 113d without a groove. The elongated hole portion 181b of the left adjustment member 180 in FIG. 14B and the elongated hole portion of the side plate 102a1 of the scanner frame portion 102a. The rectangular hole formed by overlapping with 196b is only inserted from right to left.

  Accordingly, by removing the screw 222 that attaches the intermediate member 205 to the side plate 102a2 as described above, the guide rod 113 can be pulled out from the traveling body 112 in the right direction in FIG. 14B. After the guide rod 113 is pulled out in this manner, the traveling body 112 can be taken out from the scanner frame portion 102a by separating it from a drive mechanism (not shown).

  Further, in order to mount the traveling body 112 to the scanner frame unit 102a as it is, a procedure reverse to the above-described removal procedure may be performed. That is, since the intermediate member 205 and the adjustment member 180a are still attached to one end of the guide rod 113, the small diameter portion 113d on the opposite side of the guide rod 113 is notched on the right side plate 102a2 of the scanner frame portion 102a in FIG. 14B. After being inserted through the hole 206 and passing through the rod hole 190a of the traveling body 112, it is inserted into the rectangular hole of the left side plate 102a1. Then, the intermediate member 205 is fixed to the side plate 102a2 with screws 222 as shown in FIG.

  When attaching and removing the intermediate member 205, the screw 222 and the screws 198 and 199 are not the same as the screws 198 and 199 of the adjusting member 180a. Different types such as differences in diameter or shape of the parts may be used so that differences can be clearly seen at a glance.

(Second modification of guide rod mounting structure)
Next, a second modification of the guide rod mounting structure will be described with reference to FIGS.
FIG. 30 shows a left side plate 102a1 of a modified example of the scanner frame portion 102a (sub scanning start side). The right side plate 102a2 of the scanner frame portion 102a may have a hole arrangement that is a left-right inverted version of FIG.

  In the second modification, both the height direction and the main scanning direction of one guide rod 113 inserted through the traveling body 112 can be adjusted using the adjusting member 225 of FIG. The four holes 194 to 197 on the left side formed in the side plate 102a1 in FIG. 30 correspond to the four holes 194 to 197 on the right side in FIG.

  On the right side of the side plate 102a1, a rod hole 226 for inserting a small diameter portion 113d of the guide rod 113 shown in FIG. 32A with a sufficient clearance, and a pair of screw holes 227 on both sides of the rod hole 226, Further, a pair of adjustment holes 228 are formed on both sides, and an adjustment hole 229 is formed above the rod hole 226, respectively.

  As shown in FIG. 31, the adjustment member 225 has adjustment notches 231 and 232 corresponding to the adjustment holes 228 and 229 on the left and right edges and the upper edge, respectively. Then, the jig 200 is inserted into the gap formed by the overlap between the adjustment holes 228 and 229 of the side plates 102a1 and 102a2 and the adjustment notches 231 and 232 as in FIG. 225 can be moved and adjusted in the height direction and the main scanning direction.

  A rod hole 233 for inserting and supporting the small-diameter portions 113d formed at both ends of the guide rod 113 shown in FIG. 32A is formed at the intermediate position in the left-right direction of the adjustment member 225. Screw holes 234 for fixing the adjustment member 225 to the side plate 102a1 of the scanner frame portion 102a are formed on both the left and right sides of the rod hole 233.

  At the time of adjustment, the screw 235 inserted into the screw hole 234 is loosened as shown in FIG. After the adjustment, the jig 200 is pulled out and the screw 235 is finally tightened to complete the adjustment work.

(Arrangement of light source and light guide plate to substrate)
FIG. 34 shows another example of the light source 115 and the light guide plate 150 arranged on the traveling body 112. In this example, unlike FIG. 5, the light source 115 is configured as a side view type, and is mounted on the substrate 141 at a position below the optical axes of the imaging lens 121 and the image sensor 122.

  The light emitted from the light source 115 is irradiated upward along the substrate 141, that is, upward in parallel with the second mounting surface of the substrate 141. The side view type is a type in which the light source 115 mounted on the substrate 141 emits light in a direction parallel to the mounting surface of the substrate 141.

  The light guide plate 150 is mounted on the substrate 141 above the light source. The lower-end incident surface 150a of the light guide plate 150 is disposed close to the emission surface of the light source 115, and the upper-end emission surface 150b is inclined with respect to the second mounting surface of the substrate 141 and inclined not vertically to the document. Light is emitted from the direction. Both ends of the light guide plate 150 are inserted into the notch holes 149 formed in the support portions 145b at both ends of the bracket 145 with play in the vertical direction.

  As described above, in this embodiment, the image sensor 122, the light source 115, and the light guide plate 150 are mounted on both sides of the common substrate 141. However, the height of the optical axis of the image sensor 122 and the optical axis of the imaging lens 121 are mounted. When the positions are shifted from each other, it is necessary to adjust the substrate 141 in the vertical direction. When such adjustment is performed, the height of the light source 115 and the light guide plate 150 also changes.

  Since the optical axis of the radiation surface of the light guide plate 150 is inclined with respect to the document, the light amount distribution in the document reading range is shifted in the sub-scanning direction when the height of the light guide plate 150 changes. As a result, the optical axis of the first mirror 120a on which the reflected light from the original is incident deviates from the center of the light quantity distribution, causing density unevenness of the read original and a so-called “flying” phenomenon in which the original image is poor.

  In this embodiment, such a problem is solved by arranging the light guide plate 150 with respect to the substrate 141 so that the height can be adjusted. Since the light guide plate 150 does not have an electrical connection portion with respect to the substrate 141, such an arrangement capable of moving up and down is easy.

  That is, as shown in FIG. 35, the left and right ends of the light guide plate 150 are screwed and fixed to the substrate 141 with screws 151, but the holes through which the screws 151 on the left and right ends of the light guide plate 150 are passed are vertically elongated holes 152. Therefore, by loosening the screw 151, the left and right ends of the substrate 141 can be moved in the vertical direction.

  The substrate 141 is attached to the vertical plate portion 135b of the traveling body frame 135 so as to be movable up and down in order to adjust the height of the optical axis of the image sensor 122.

  When the light source 115 is mounted on the substrate 141 instead of the side view type and mounted on the substrate 141, the light guide plate 150 must be separated from the substrate 141, so that the space in the sub-scanning direction of the traveling body 112 becomes large. In addition, if only the light guide plate 150 is moved up and down, the optical path between the light source 115 and the light source 115 is shifted, so that a complicated structure for moving the light source 115 in the same manner as the light guide plate 150 is moved is required. The structure of FIG. 34 does not have such a problem, and the traveling body 112 can be made compact in the sub-scanning direction by mounting the light guide plate 150 on the substrate 141.

  As shown in FIG. 36A, the optical axis of the image sensor 122 is lowered by slightly lowering the substrate as shown in FIG. 36B from the normal state where the center of the light amount distribution coincides with the reading position of the document. In this case, the distance A from the light guide plate 150 to the original increases to the distance B, and the center of the light amount distribution in the reading range of the original is shifted to the left. Therefore, when such a deviation in the light amount distribution occurs, the screws 151 that fix the left and right ends of the light guide plate 150 are loosened, and the light guide plate 150 is raised by the amount that the substrate 141 is lowered (distance h = B−A). Then tighten the screw 151 again. As a result, the distance from the light guide plate 150 to the original returns to A, the center of the light quantity distribution coincides with the optical axis of the first mirror 120a, and the deviation of the light quantity distribution with respect to the reading position of the original can be easily corrected. .

  The embodiments and modifications of the present invention have been described above, but the present invention is not limited to the above-described forms and modifications, and various modifications can be made within the scope of the technical idea described in the claims. It is.

DESCRIPTION OF SYMBOLS 100: Image forming apparatus 102: Image reading apparatus 102a: Scanner frame part 102b: Scanner cover part 112: Traveling body 113, 114: Guide rod 115: Light source 120a: 1st mirror (reflection means)
120b: Second mirror (reflection means)
120c: Third mirror (reflecting means)
120d: 4th mirror (reflection means)
120e: fifth mirror (reflecting means)
121: Imaging lens 122: Image sensor (reading means)
127: timing belt 128: motor 141: substrate 150: light guide plate 161: mirror mounting member 162: adjustment screw 165: scale 173: adjustment screw 175: fulcrum portion 180, 186, 225: adjustment member 200: jig 205: intermediate member

JP 2010-4365 A (FIGS. 3 and 16) JP 2008-172562 A (FIG. 2)

Claims (17)

A light source for exposing the reading range of the document in the main scanning direction;
Reading means for reading reflected light from the document;
Reflection means having a plurality of mirrors that sequentially reflects reflected light from the document and guides it to the reading means;
An imaging lens for imaging the reflected light reflected by the reflecting means and guiding it to the reading means;
An image reading apparatus comprising: a light source, a reading unit, and a traveling body mounted with specific mirrors of the reflection unit and movable in a sub-scanning direction for scanning the document,
An image reading apparatus in which the reflecting means excluding a specific mirror mounted on the traveling body is disposed outside the traveling body.   At least two mirrors of the reflecting means arranged outside the traveling body are disposed corresponding to two positions of the scanning start end and the scanning end end in the sub-scanning direction of the traveling body, and between the two mirrors. The image reading apparatus according to claim 1, wherein an optical path of the reflected light is formed.   Two at least four mirrors of the reflecting means arranged outside the traveling body are disposed in correspondence with two positions of the scanning start end and the scanning end end in the sub-scanning direction of the traveling body, and the scanning start The image reading apparatus according to claim 1, wherein an optical path of the reflected light is formed between two end-side mirrors and between two mirrors on the scanning end end side. Mirror bottom arrangement Of the two mirrors arranged corresponding to the two positions of the scanning start end and the scanning end end, two mirrors farther from the original are arranged at the bottom of the casing of the image reading apparatus. The image reading apparatus according to claim 3. The length of the mirror arranged in correspondence with the position of the scanning start end in the main scanning direction is longer than the length of the mirror arranged in correspondence with the position of the scanning end end in the main scanning direction. The image forming apparatus according to any one of 2 to 4.   The image reading apparatus according to claim 1, wherein a specific mirror mounted on the traveling body is disposed at a rear end of the traveling body.   Reflected light from the document is reflected to the rear side of the traveling body by the specific mirror of the traveling body, and the reflected light is arranged corresponding to the scanning start end of the traveling body in the sub-scanning direction. The image reading apparatus according to claim 2, wherein the reflected light is sequentially reflected by a plurality of subsequent mirrors.   The reflected light sequentially reflected by the plurality of mirrors is reflected toward the traveling body by a mirror disposed in correspondence with the position of the scanning end of the traveling body in the sub-scanning direction. 4. The image reading apparatus according to claim 2, wherein the image reading apparatus is guided to the reading unit.   The image reading apparatus according to claim 1, wherein the imaging lens is mounted on the traveling body in front of the reading unit.   A substrate extending in a direction crossing the sub-scanning direction is disposed on the traveling body, the reading unit is disposed on a first mounting surface formed on one side surface of the substrate, and formed on an opposite side surface. The image reading apparatus according to claim 1, wherein the light source is disposed on the second mounting surface.   The image reading apparatus according to claim 10, wherein the specific mirror is disposed on a side of the substrate on which the light source is disposed.   The image reading apparatus according to claim 11, wherein the light source, the specific mirror, and the substrate are arranged in a range in a height direction when the imaging lens is viewed from the sub-scanning direction.   The image reading apparatus according to claim 12, wherein the light from the light source is applied to the document through a light guide plate.   The image reading apparatus according to claim 13, wherein the traveling body is driven in the sub-scanning direction by a driving unit connected to one end of the traveling body in the main scanning direction.   The image reading apparatus according to claim 4, wherein a lower edge of the mirror of the reading unit disposed at the bottom of the housing of the image reading apparatus is chamfered in the horizontal direction.   An image forming apparatus comprising the image reading apparatus according to claim 1.   An image forming apparatus in which an automatic document feeder is attached to the image reading apparatus according to claim 1.

Images