JPH08298573A - Image reader - Google Patents

Abstract

PURPOSE: To realize an image reader in which the dust on an optical path is provented from forming an image on a CCD and an excellent image can be obtained. CONSTITUTION: The reading window 11a of the device main body 10 of an image reader is sealed by a fluorescent lamp 23 illuminating an original P and a glass 24 for dustproof, etc. The reflected light C from the original P by the illumination of this fluorescent lamp 23 is read as video by each of a reflection mirror 25, a lens 26 and a CCD. Each of the reading surface 24a and the dustproof surface 24c of the glass 24 is arranged so that they may be parallel and be opposed with each other in luminous flux guiding the reflected light C from the original P to the side of the lens 26. With these arrangements, this device is composed so as to satisfy the condition of 0.1×Lg< DL×Lo×N (Lg: the length along the optical axis of the dustproof surface 24c of the original P and the glass 24 for dustproof, Lo: the converted air optical path length along the optical axis of the original P and the lens 26, DL: the front valid diameter of the lens 26, N: the refractive index of the glass 24 for dustproof).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus capable of easily reading the content of an object to be read such as a document as an image.

[0002]

2. Description of the Related Art For example, a stationary scanner is known in which the paper surface (contents of description) of a document is read as an image (image). In this scanner, a document to be read is inserted between the scanner body and a lid that holds the document, and the document is illuminated by a light source provided on the scanner body side at the time of reading. An inclined flat glass plate is provided on the bottom surface of the scanner body near the light source so that dust such as dust cannot enter the scanner body from the outside.

Then, the reflected light from the original is imaged on the charge coupled device (CCD) from the inclined flat glass plate through a reflection mirror or lens arranged in the scanner body, converted into an electric signal, and the image is formed. It is designed to read.

[0004]

In the above-mentioned conventional stationary scanner, a flat glass plate is provided on the bottom surface of the scanner body near the light source to prevent dust from entering the scanner body. When dust adheres to the inner surface of the flat glass plate in the scanner body, the reflection mirror and the lens, the dust on the optical path forms an image on the CCD,
There is a drawback that a line image appears in the scanning direction and the quality of the read image deteriorates.

Therefore, according to the present invention, it is possible to always obtain a good read image by preventing dust on the optical path that enters from the outside of the apparatus main body or is generated inside the apparatus main body from forming an image on the line sensor. The present invention provides an image reading device that can be used.

[0006]

A light source for illuminating an object to be read so as to close the reading window and a dust-proof transparent member are formed by opening a reading window at a predetermined position of a substantially sealed casing-type apparatus main body. And illuminating the object to be read with this light source, and reflecting light from the object to be read from the dust-proof transparent member through at least one reflecting mirror and lens disposed in the apparatus main body on the line sensor. An image reading device for forming an image on an image and converting it to an electric signal to read an image, wherein a reading surface and a dust-proof surface of the dust-proof transparent member are used to reflect light reflected from the object to be read. In the light flux guided to the lens side, they are arranged so as to be parallel and face each other, and are configured to satisfy the following condition (1).

(1) 0.1 × Lg <DL × Lo × N where Lg is the length along the optical axis of the object to be read and the dust-proof surface of the transparent member Lo: is the optical axis of the object to be read and the lens Air conversion optical path length along DL: Effective diameter of front lens of lens N: Refractive index of transparent member

[0008]

Even if dust such as dust adheres to the reading surface and the dust-proof surface of the dust-proof transparent member and the lens, it forms a line image in the scanning direction of the dust on the optical path and is formed on the line sensor. No image is formed, a good read image is always obtained, and the quality of the read image is further improved.

[0009]

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

In FIGS. 1, 2 and 10 and 11, reference numeral 1 is a handy type image reading apparatus. This image reading apparatus 1 is arranged via a substantially sealed synthetic resin casing-shaped apparatus main body 10 and a synthetic resin casing-shaped chassis (mold frame) 21 inside the apparatus main body 10 to be read. Paper surface of the original P as an article (contents of description)
An image reading optical system 20 for reading the image as an image and a bottom lid (lid body) 30 made of synthetic resin and detachably attached to the apparatus main body 10 to guide the original P or the like by pressing. It is configured.

As shown in FIGS. 1, 2 and 5, the apparatus main body 10 is composed of a lower cabinet 11 made of synthetic resin having an open upper surface side and a plurality of integrally formed downward projections formed by a ceiling wall section with a lower surface side opening. By fixing the lower cabinet 11 to the cylindrical portion 12a of the book with screws, the lower side opening edge is substantially sealed with the synthetic resin upper cabinet 12 fitted to the upper side opening edge of the lower cabinet 11. It is formed in a box shape. A reading window 11a is formed at a substantially central portion of the lower cabinet 11 so as to be elongated in a rectangular shape in the front-rear direction in the drawing (direction orthogonal to the reading direction indicated by an arrow in the use state of FIG. 11). . The reading window 11a is a unit of a long fluorescent lamp (light source) 23 for illuminating the original P and the like, and a long dust-proof glass (dust-proof transparent member) 24 having a sealed space inside. It is closed by the transformed unit body 22.

The unitized fluorescent lamp 23
The original P or the like is illuminated by the line sensor, and the reflected light C from the original P or the like is transmitted from the dustproof glass 24 through a pair of reflection mirrors 25, 25 and a lens 26 respectively arranged at predetermined positions in the chassis 21. An image is formed on a charge-coupled device (CCD) 27, and converted into an electric signal so that the description content of the original P or the like can be read as an image. The chassis 21, the fluorescent lamp 23, the dustproof glass 24, the pair of reflection mirrors 25 and 25, and the lens 2
The image reading optical system 20 is constituted by 6 and the CCD 27.

A synthetic resin unit body 22 in which the fluorescent lamp 23 and the dustproof glass 24 are integrally formed is provided in a central upper portion thereof in a front-back direction in the drawing (orthogonal to a reading direction indicated by an arrow in a use state of FIG. 11). The opening portion 22a extending in a rectangular shape is formed in the direction of the arrow. Further, as shown in FIG. 5, the left side portion 22b of the unit body 22 is formed in a substantially quarter-cylindrical shape, and the right side portion 22c is formed in an inclined shape of about 45 degrees. Further, the left side portion 2 of the unit body 22
The inner surface of 2b (the surface on the fluorescent lamp 23 side) is provided with a first reflector 28a for reflecting the light beam from the fluorescent lamp 23 to the original P side and the like, and the right side portion 2 of the unit body 22.
On the inner surface of 2c, from the fluorescent lamp 23 to the dustproof glass 24
The second ray that reflects the light beam that has passed through to the original P side again.
The reflector 28b is provided. These first and second reflectors 28a and 28b are made of a white plastic film having a high reflectance.

The first and second reflectors may be formed by directly forming a reflecting mirror surface on the inner surface of the left side portion 22b and the inner surface of the right side portion 22c of the unit body 22 by means such as metal deposition. The right side surface 22c of the main body 22 and the second reflector 28b may be respectively formed in a curved surface shape to further increase the light condensing degree.

Further, as shown in FIG. 5, the dustproof glass 2
4 is a reading window 11a opened in the lower cabinet 11.
A lower half 24A having a substantially rectangular plate shape having a reading surface 24a that closes the opening, a long first inclined surface 24b that is obliquely inclined about 45 degrees toward the fluorescent lamp 23, and a length that closes the opening 22a of the unit body 22. A space that is internally sealed by a long dust-proof surface 24c and a long second inclined surface 24d that abuts the right side surface 22c of the unit body 22 via a second reflector 28b and an upper half 24B having both side surfaces 24e. It is (hollow). Further, the reading surface 24a and the dust-proof surface 24c of the dust-proof glass 24 allow the lens 26 to reflect the reflected light C from the document P or the like.
The light beams guided to the side are arranged so as to be parallel to each other and face each other, and are configured to satisfy the following condition (1).

0.1 × Lg <DL × Lo × N (1) where, Lg: length of the original P and the like and the dustproof surface 24c of the dustproof glass 24 along the optical axis Lo: original P and the lens Air-converted optical path length along the optical axis of 26 DL: Effective diameter of front lens of lens 26 N: Refractive index of dustproof glass 24 Further, as shown in FIGS.
5 and 25 are a pair of metal leaf springs (elastic members) 2
The casings (mold frames) 21, which are made of synthetic resin and are made of a synthetic resin, are held via 9 and 29 so as to be inclined at a predetermined angle between the upper center and the left center. That is, the upper end of each leaf spring 29 has a V-shaped holding portion 29a for holding the upper surface side of the reflection mirror 25, and the pair of substantially L-shaped holding portions 2 for holding the end surface of the reflection mirror 25 on both upper sides thereof.
9b and 29b, and a pair of inverted V-shaped locking portions 29c and 29c, which are inserted into the pair of engaging holes 21c and 21c of the chassis 21 and are locked to the back side, at the lower ends thereof. An engaging portion 29d that is engaged with the lower surface side of the protruding portion 21d of the chassis 21 is integrally formed by press molding.

As shown in FIG. 8, the width between the bent portion of the pressing portion 29a of each leaf spring 29 and the locking portion 29d is between the upper surface of the reflection mirror 25 and the lower surface of the protruding portion 21d of the chassis 21. It is set smaller than the dimension E. As a result, the reflection mirror 25 and the protrusion 21d of the chassis 21 are sandwiched between the pressing portion 29a and the locking portion 29d of each leaf spring 29, and the reflection mirror 25 is chassis by the elastic force of each leaf spring 29. It is always pressed against the 21st side so that a stable angle can be maintained. Further, the pair of pressing portions 29b, 29b of the leaf springs 29 are brought into contact with the end surface of the reflection mirror 25, so that the reflection mirror 25 comes off (X in FIG. 8).
It is designed to prevent the slipping in the direction). further,
As shown in FIG. 9, a pair of locking portions 29 of each leaf spring 29.
Dimension G of both ends of c and 29c is set larger than pitch dimension H of a pair of engagement holes 21c and 21c of chassis 21. Then, the pair of locking portions 29c, 2 of each leaf spring 29
When 9c is fitted into the pair of engagement holes 21c, 21c of the chassis 21, each locking portion 29c is bent by its elastic force, so that each locking portion 29c can be expanded after passing through each engagement hole 21c. This prevents the leaf spring 29 itself from coming off. At this time, the pair of locking portions 29c of each leaf spring 29,
By setting the dimension F between the tip of 29c and the spring body side as shown in FIG. 9, the rattling of each leaf spring 29 is eliminated. Further, the widthwise fixing of the reflection mirror 25 is performed without rattling by setting the width of the notch 21e of the chassis 21 to be the same as the width of the reflection mirror 25.

As shown in FIGS. 4 and 5, the lower cabinet 11 of the apparatus main body 10 has a pair of openings 11b and 11b on both sides thereof (the document insertion port side and the document ejection port side) so as to sandwich the reading window 11a. 11c and 11c are formed, respectively. A pair of openings 1 of the lower cabinet 11
The lower side of the pair of feed rollers 15 and 15 fixed to the shaft 14 is exposed to the outside from 1b and 11b, and the pair of openings 11 of the lower cabinet 11 is exposed.
The lower side of a pair of discharge rollers 15 'and 15' for discharging, which are fixed to the shaft 14 ', are exposed to the outside of c and 11c, respectively. The shafts 14 and 14 'are rotatably supported by a pair of bearings 21a and 21b provided on the chassis 21 shown in FIG. 7, and as shown in FIGS. A gear 14a is provided at one end of the shafts 14 and 14 '.
Are fixed respectively. Each gear 14a is indirectly meshed with the drive gear 17a of the motor 17 via a plurality of intermediate gears 16.

As shown in FIGS. 1, 2 and 5, the bottom lid 30
Is a lower cabinet 31 made of synthetic resin whose upper surface is open.
The lower cabinet 31 is formed in a cylindrical portion 32a that is formed in a rectangular plate shape and integrally protrudes downward due to its substantially center.
Is fixed with a screw 33, and the peripheral edge portion is fitted into the upper side opening edge portion of the lower cabinet 31 to form an upper cabinet 32 made of synthetic resin into a casing type.

As shown in FIG. 5, a pair of openings is provided at a position facing the pair of openings 11b, 11b and 11c, 11c of the lower cabinet 11 of the apparatus main body 10 of the upper cabinet 32 of the bottom lid 30. Parts 32b, 32b and 32
c and 32c are formed respectively. From the pair of openings 32b, 32b of the upper cabinet 32, the shaft 34
The upper sides of the pair of driven rollers 35, 35 for feeding which are fixed to the sheet are exposed, respectively, and the shaft 34 'is extended from the pair of openings 32d, 32d of the upper cabinet 32 to the outside.
A pair of driven rollers 35 ', 35' for discharging the sheet, which are fixed to the sheet
The upper side of each is exposed. These shafts 34, 3
4'is rotatably supported downward along each pair of shaft guides 36, 36 provided in the lower cabinet 31, and is fixed to the lower end of the cylindrical portion 32a of the upper cabinet 32 by a screw 33. Leaf spring 3 as a member
It is supported by both ends of 7 such that it is always elastically biased upward. As a result, the pair of driven rollers 35, 35 and 35 ', 35' are brought into pressure contact with the pair of driving rollers 15, 15 and 15 ', 15', respectively.
It is designed to rotate together with 5 '.

Further, an optical sensor 18 for detecting the size of the original P or the like is arranged via a substrate 19 on the side (original insertion port side) of the paper feed drive roller 15 in the apparatus main body 10. . As shown in FIG. 3, the optical sensor 18 is composed of one light emitting diode (LED) 18a as a light emitting portion and three light receiving portions 18b, 18b, 18b. Each opening 11 is provided in the lower cabinet 11 of the device body 10 facing the light emitting diode 18a and the three light receiving portions 18b.
d are formed respectively. The upper cabinet 32 of the bottom lid 30 facing the openings 11d has openings 32d.
Are formed respectively. The lower cabinet 31 and the upper cabinet 32 of the bottom lid 30 facing the respective openings 32d.
A glass prism (optical path changing means) 38 is interposed between the and. The four inclined surfaces 38a of this prism 38
38d to guide light emitted from one light emitting diode 18a of the optical sensor 18 to the three light receiving portions 18b, 18b, 18b of the optical sensor 18 to detect the paper width (size) of the original P or the like. There is.

Further, as shown in FIG. 4, a pair of paper guides 32e, 32e are provided on the upper cabinet 32 of the bottom lid 30.
Are formed integrally with each other. This pair of paper guides 32
lower cabinet 1 of the device body 10 facing the e and 32e
1 has a pair of concave groove portions 11e, 11e into which the tip ends of the pair of paper guides 32e, 32e enter. Further, as shown in FIGS. 1 and 2, a pair of paper width guides 39, 39 are provided slidably in a direction of approaching and separating from the insertion port side of the original P or the like of the upper cabinet 32 of the bottom cover 30. When the pair of paper width guides 39, 39 are separated from each other at the maximum distance, the maximum A6 size original paper can be guided and inserted.

Further, as shown in FIGS. 1 and 5, a reading switch 41 and a substrate 40 on which an electric circuit (not shown) is mounted are arranged on the chassis 21 in the apparatus body 10. The reading switch 41 is turned on and off by a pressing operation of a reading button 42 exposed and projected on the upper surface side of the apparatus body 10 to drive and stop the motor 17. The motor 17 is also driven by the optical sensor 18 detecting that the original P or the like is fed and the paper width of the original P or the like through the electric circuit of the substrate 40.

Further, as shown in FIG.
A hinge shaft 43 is provided on the document exit side of the lower cabinet 11.
An L-shaped lock lever 44 is provided on the document insertion port side. The hinge shaft 43 and the lock lever 44 are attached to the bottom cover 3
A state in which the bottom lid 30 maintains a predetermined slit (space) for feeding the paper with respect to the lower surface (bottom surface) of the apparatus main body 10 by connecting the hinge bearing 45 and the hook 46, which are provided to protrude from the upper cabinet 32 of No. 0, respectively. It can be installed with. Further, by pushing down the document insertion opening side of the bottom lid 30 to release the locked state of the hook 46 against the elastic force of the lock lever 44, as shown by the one-dot chain line in FIG. The lid 30 can be easily removed from the apparatus body 10.

In FIG. 11, reference numeral 47 is a power supply cord, which supplies power to the fluorescent lamp 23, the motor 17 and the like of the apparatus body 10. A video output code 48 is connected to a video input terminal of a TV (television receiver), a VTR (video tape recorder) or the like, and is connected to the CCD 27.
The video output signal from the device is sent to the TV or VTR.

According to the image reading apparatus 1 of the above embodiment, for example, when the paper surface of the fixed original P is read,
It is performed in a stationary state with the bottom cover 30 attached to the bottom surface side of the apparatus body 10. That is, when a fixed-size document P to be read is inserted from the document insertion port between the device body 10 and the pair of paper width guides 39, 39 of the bottom cover 30, the optical sensor 18 on the document insertion port side of the device body 10 causes The fact that the original P has been inserted and the paper width of the original P are detected.

The detection state will be described in detail with reference to FIG. 3. The light emitted from one light emitting diode 18a of the optical sensor 18 has an opening 11d in the lower cabinet 11 of the apparatus body 10 and an opening in the upper cabinet 32 of the lid 30. After passing through 32d, it is reflected twice by the inclined surface (internal reflecting surface) 38a of the prism 38 and each of the other inclined surfaces (internal reflecting surface) 38b, 38c, 38d, and the three light receiving portions 18 of the optical sensor 18 are provided.
It is led to each position of b, 18b, 18b. Here, when the document P is inserted between the lower cabinet 11 of the apparatus body 10 and the upper cabinet 32 of the bottom cover 30, the light emitted from one light emitting diode 18 a of the optical sensor 18 is emitted from the optical sensor 18. Before the light reaches the respective light receiving portions 18b, it is blocked by the document P. In FIG. 3, the original P
The two inner light-receiving portions 18b, 18b are respectively blocked by, and the light is guided only to the light-receiving portion 18b near the groove 11e. At this time, the paper width of the document P is detected and determined by the positions of the two light receiving portions 18b, 18b to which the inner light is not guided. That is, the optical sensor 18 detects the presence or absence of the paper of the original P and detects the paper width of the original P.

Next, the motor 17 is driven by the paper width detection signal from the optical sensor 18 and the pair of drive rollers 15 and 15 on the paper feed side and the pair of drive rollers 15 'on the paper discharge side are driven via the intermediate gear 16. , 15 'are rotated respectively, and a pair of drive rollers 15 and 15 on the paper feed side and a pair of driven rollers 3 are provided.
The original P is smoothly sent to the reading window 11a side of the apparatus main body 10 while sandwiching the original P between the sheets 5 and 35. The reading window 11 where the original P serves as the reading point of the image reading optical system 20
When the document P is sent to the lower side of a (the intermediate position between the apparatus main body 10 and the bottom cover 30), the read content of the original P is changed to the fluorescent lamp 2.
3 is illuminated via each of the reflectors 28a and 28b,
The reflected light C from the illuminated document P is the dustproof glass 2
It passes through the reading surface 24a and the dustproof surface 24c of No. 4 and is reflected by the pair of reflecting mirrors 25, 25. The reflected light C whose direction is changed by the pair of reflecting mirrors 25, 25 is reflected by the lens 26.
The light is collected by and is focused on the image pickup surface of the CCD 27. The image formed on the image pickup surface of the CCD 27 is converted into an electric signal, converted into a video signal through an electric circuit (not shown) of the substrate 40, and as a video output signal through a video output code 48, a TV or VTR (not shown). Etc. As a result, the content of the document P can be easily read as an image.

The read original P is smoothly sent as it is by the pair of driving rollers 15 and 15 on the sheet feeding side and the pair of driven rollers 35 and 35 for feeding the sheet, and the pair of driving rollers on the sheet discharging side. It is sandwiched between 15 'and 15' and a pair of driven rollers 35 'and 35' on the paper discharge side. Then, the pair of drive rollers 15 ', 15' on the paper discharge side and the pair of driven rollers 35 ', 35' on the paper discharge side are completely and smoothly sent to the document discharge port to complete the reading operation.

In this way, the optical sensor 1 of the apparatus body 10 is
The light emitted from the light emitting diode 18a of No. 8 is guided to each light receiving portion 18b of the optical sensor 18 of the apparatus main body 10 by the prism 38 of the bottom lid 30, so that the document is extended from the apparatus main body 10 to the bottom lid 30 side. Electric wiring for detecting the size of P or the like is unnecessary, and the bottom cover 30 can be easily removed from the apparatus body 10 as shown in FIG.
Thus, as shown in FIG. 11, when reading an original (object to be read) P ′, a book (object to be read) P ″, a photograph (not shown), etc., which is out of the standard size, only the apparatus main body 10 is used as a handy scanner. Can be used for reading regardless of the size of an object to be read such as a manuscript, etc. Further, when only the apparatus main body 10 is used like a handy scanner, a pair of driving rollers 15, 15 and 1 are provided.
A self-propelled scanner is formed by 5'and 15 '.

A detailed description will be given of the case of reading the above-mentioned non-standard-sized original P ', etc. The apparatus main body 10 with the bottom cover 30 removed.
Is placed on the original P ′ out of the standard size, and as shown in FIG.
When the reading button 42 provided on the upper portion of the apparatus main body 10 is pressed, the motor 17 is driven via the reading switch 41 and the intermediate gear 16 causes the pair of driving rollers 15 on the sheet feeding side to move.
15 and a pair of drive rollers 15 ', 15' on the paper discharge side rotate. The pair of drive rollers 15 on the paper feed side,
By rotating 15 and a pair of drive rollers 15 ', 15' on the discharge side, the apparatus main body 10 itself travels (self-propelled) on a non-standard-sized original P '. This self-propelled device body 1
By moving the reading window 11a of 0 on the non-standard original P ', the desired description content of the original P'can be freely read as an image regardless of the size of the original P'. The reading operation is completed by stopping the motor 17 at the end of this reading. When reading this,
Since the motor 17 rotates at a constant speed, the paper reading speed becomes almost constant and the amount of data read by the CCD 27 can be taken out at a constant speed.
It is possible to eliminate the occurrence of data overflow, etc. that occurs when the user presses with their hands.

At the time of reading the fixed original P and the non-standard original P'through the reading window 11a of the apparatus main body 10,
The reading window 11a is closed by a unitized fluorescent lamp 23 and a dustproof glass 24, and the dustproof glass 24 is closed.
The reading surface 24a and the dust-proof surface 24c are arranged so as to be parallel to each other and face each other in the light flux that guides the reflected light C from the original P or the like to the lens 26 side.
Lg <DL × Lo × N (where Lg: the length of the original P or the like and the dustproof surface 24c of the dustproof glass 24 along the optical axis, L
O: the air-converted optical path length along the optical axis of the original P and the lens 26, DL: effective diameter of the front lens of the lens 26, N: refractive index of the dustproof glass 24). Even if dust such as dust adheres to the reading surface 24a and the dustproof surface 24c of the dustproof glass 24 and the lens 26, the image reading optical system 20 is out of focus and the dust on the optical path is C.
No image is formed on the CD 27. As a result, a good image is obtained without forming a line image in the scanning direction of the dust on the CCD 27, and the quality of the read image can be further improved.

Further, the reading surface 24a and the dustproof surface 24c of the dustproof glass 24 are parallel and face each other, and
Since the reading surface 24a is substantially flush with the bottom surface of the apparatus main body 10, the paper surface of the document P or the like is read by the image reading optical system 2.
With 0, smooth and easy and reliable continuous reading can be performed, and color misregistration does not occur in the read image. Further, since the first reflector 28a and the second reflector 28b are provided on the cylindrical left side portion 22b and the inclined right side portion 22c of the unit body 22 in which the fluorescent lamp 23 and the dustproof glass 24 are unitized, the fluorescent lamp is provided. It is possible to reliably focus the light beam from the light beam 23 on the reading point of the document P or the like of the image reading optical system 20 to improve the illumination efficiency. Further, the unit body 22 allows the two parts of the fluorescent lamp 23 and the dustproof glass 24 to be integrated into one unit, which saves space and reduces the size and thickness of the apparatus main body 10, that is, the image reading apparatus 1 as a whole. The weight can be further reduced.

Further, at both ends of each reflection mirror 25 of the image reading optical system 20, a pair of engaging portions 29c, 29c of each metal plate spring 29 which is a press part is provided with a pair of engaging portions of a chassis 21 made of synthetic resin. It can be easily and securely attached by simply fitting it into the fitting holes 21c, 21c with one touch, and can be securely held and fixed at a predetermined position of the chassis 21 in a stable state without using screws, rivets, adhesives, or the like. . As a result, the number of parts can be reduced because screws or the like are unnecessary, and the cost can be further reduced. That is, as shown in FIG. 8, the bent portion of the holding portion 29a of each leaf spring 29 and the pair of holding portions 29b,
With 29b, the upper surface and the end surface of the reflection mirror 25 are always pressed against the chassis 21 side so as to be securely held. Further, as shown in FIG. 9, the tip ends of the pair of locking portions 29c, 29c of the leaf springs 29 are locked in the pair of engaging holes 21c, 21c of the chassis 21 by being prevented from coming off and being locked. The spring 29 is securely fixed to the chassis 21 without rattling. As a result, the reflection mirror 25 is held and fixed by the pair of leaf springs 29, 29 in all directions. The pressing portion 29a of the leaf spring 29 and the locking portion 2
Dimension E of 9d and dimension G between the pair of locking portions 29c, 29c
By setting the dimensions such as the above and varying the plate thickness, it is possible to mount a reflection mirror of any width and thickness.

FIG. 12 shows a dustproof glass (dustproof transparent member) 24 of the second embodiment. The upper half 24B 'having the dustproof surface 24c of the dustproof glass 24 extends to the substrate 40 side, and the reflection mirror surface 24 inclined to the upper end surface thereof.
f is formed. The reflection mirror surface 24f that changes the direction of the optical path reduces the number of one reflection mirror 25 to save space and reduce cost, and at the same time, the apparatus body 10
Dust on the optical path inside does not form an image on the CCD 27.

Further, FIG. 13 shows a dustproof glass (dustproof transparent member) 24 of the third embodiment. The upper half 24B ″ having the dustproof surface 24c of the dustproof glass 24 extends to the center of the chassis 21 and has an inclined reflection mirror surface 24g formed on the upper end surface thereof. A reflection mirror for changing the direction of the optical path. The surface 24g eliminates the pair of reflecting mirrors 25, 25 to further save space and reduce cost as compared with the second embodiment, and dust such as dust on the optical path in the apparatus main body 10 is detected by the CCD 27. It is designed not to image on top.

The dustproof glass (transparent member for dustproofing) that closes the reading window 11a of the apparatus body 10 is shown in FIG.
A lower half 24A and an upper half 24B, like a dustproof glass (dustproof transparent member) 24 'shown in (a).
You may fill the solid part 24C in the closed space of
Alternatively, the whole may be integrally formed as in another embodiment of the dustproof glass (dustproof transparent member) 24 ″ shown in FIG.

Further, FIGS. 15A and 15B show a fourth embodiment. In the fourth embodiment, the cleaning brush 6 is planted on the rotary shaft 61 at a position above the dustproof surface 24c of the dustproof glass 24 so as not to block the reading optical path and the illumination optical path.
0 is rotatably provided. This cleaning brush 6
By turning 0, dust generated during use and dust accumulated on the dust-proof surface 24c of the dust-proof glass 24 are cleaned and removed, and the reading optical path is not blocked by dust. It should be noted that the cleaning brush 60 may be slid instead of being rotated to clean dust adhering to the dustproof glass.

Further, FIGS. 16 (a) and 16 (b) show a fifth embodiment. In this fifth embodiment, the dustproof glass 2
4, the air injection pipe 70 is arranged at a position above the dustproof surface 24c where the reading optical path and the illumination optical path are not blocked, and the air injected from the nozzle 70a of the air injection pipe 70 adheres to the dustproof surface 24c of the dustproof glass 24. The dust is blown away and cleaned. That is, the operation button 71 attached to the apparatus body 10 is replaced with the compression coil spring 7.
When pressed against the urging force of 2, the air reservoir 73 is pressed and air is discharged from the nozzle 70a of the air injection pipe 70. When the pressed state of the operation button 71 is released, the operation button 71
Is raised by the compression coil spring 72, and air is injected into the air reservoir 73 via the check valve 74. This allows
As in the fourth embodiment, dust generated during use and dust accumulated on the dust-proof surface 24c of the dust-proof glass 24 are removed so that the reading optical path is not blocked. In the fifth embodiment, the upper side of the air reservoir 73 is pressed by the operation button 71 which moves vertically, but the operation button 71 is provided slidably in the left and right direction so that the air reservoir 73 can be pushed from the side. Nozzle 70a of the air injection pipe 70
More air may be discharged.

According to each of the above-mentioned embodiments, the dustproof glass is used as the dustproof transparent member for closing the reading window of the apparatus body, but a transparent synthetic resin (plastic) is used as the dustproof transparent member. May be. Further, although the leaf spring made of metal is used as a means for attaching the reflection mirror to the chassis, an elastic member made of synthetic resin may be used. Further, although the glass prism is used as the optical path changing means, a reflecting mirror or a transparent synthetic resin prism may be used as the optical path changing means.

[0041]

As described above, according to the present invention, a reading window is opened at a predetermined position of a substantially sealed casing type apparatus main body, and an object to be read is illuminated so as to close the reading window. A light source and a dust-proof transparent member are provided, and the light source illuminates the object to be read, and reflected light from the object is read from the dust-proof transparent member by at least one reflection arranged in the apparatus main body. An image reading apparatus for forming an image on a line sensor through a mirror and a lens, converting the electric signal into an electric signal, and reading the image, wherein the reading surface and the dust-proof surface of the dust-proof transparent member are covered by the object. In the light flux that guides the reflected light from the reading object to the lens side, they are arranged in parallel and face each other, and
0.1 × Lg <DL × Lo × N (where Lg is the length along the optical axis between the object to be read and the dust-proof surface of the transparent member, Lo:
Air equivalent optical path length along the optical axis of the object to be read and the lens,
DL: the front diameter of the lens, N: the refractive index of the transparent member are satisfied, so that the optical path can be introduced from the outside of the device body or generated inside the device body. It is possible to always obtain a good read image because dust does not form an image on the line sensor.

Further, a cleaning brush is movably provided above the dust-proof surface of the dust-proof transparent member at a position where the reading optical path and the illumination optical path are not blocked, and the dust-proof surface of the transparent member is moved by moving the cleaning brush. To be cleaned,
Alternatively, an air injection pipe is arranged above the dust-proof surface of the dust-proof transparent member at a position where the reading optical path and the illumination optical path are not blocked, and the dust-proof surface of the transparent member is cleaned by the injection air of the air injection pipe. By doing so, dust adhering to the dust-proof surface of the dust-proof transparent member can be forcibly removed by the cleaning brush or the air injection pipe, and a good read image can always be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an image reading apparatus showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the image reading device as viewed from the drive system side.

FIG. 3 is a partially enlarged cross-sectional view of an optical sensor portion that detects the size of a document of the image reading apparatus.

FIG. 4 is a partially enlarged sectional view of a driving roller and a driven roller portion of the image reading device.

FIG. 5 is an enlarged explanatory diagram of an image reading optical system of the image reading apparatus.

FIG. 6A is a plan view of a chassis used in the image reading optical system, and FIG. 6B is a side view of the chassis.

FIG. 7 is an enlarged side view of the chassis.

8 is a cross-sectional view taken along the line AA of FIG.

9 is a sectional view taken along the line BB of FIG.

FIG. 10 is an explanatory diagram showing a state in which the bottom cover is removed from the main body of the image reading apparatus.

FIG. 11 is a perspective view showing a usage state of the image reading apparatus.

FIG. 12 is an enlarged explanatory diagram of an image reading optical system of the image reading apparatus of the second embodiment.

FIG. 13 is an enlarged explanatory diagram of an image reading optical system of the image reading apparatus of the third embodiment.

FIG. 14 (a) is a cross-sectional view of another embodiment of the dustproof glass,
(B) is sectional drawing of the dustproof glass of another aspect.

FIG. 15A is a side view showing a state in which the dustproof surface of the dustproof glass of the fourth embodiment is cleaned with a cleaning brush, and FIG. 15B is a perspective view of the same.

16 (a) is a side view showing a state in which the dust-proof surface of the dust-proof glass of the fifth embodiment is removed by injecting air from an air injecting pipe, and FIG. 16 (b) is a perspective view of the removed state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image reading device 10 ... Device main body 11a ... Reading window 23 ... Fluorescent lamp (light source) 24 ... Dustproof glass (dustproof transparent member) 24a ... Reading surface 24c ... Dustproof surface 24f, 24g ... Reflecting mirror surface 25 ... Reflection Mirror 26 ... Lens 27 ... Charge-coupled device (line sensor) 28a ... First reflector 28b ... Second reflector 60 ... Cleaning brush 70 ... Air injection pipe P ... Original (read object) P '... Non-standard original (Object to be read) P "... Book (Object to be read) C ... Reflected light

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[Procedure amendment]

[Submission date] May 22, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 12

[Correction method] Change

[Correction content]

[Fig. 12]

Front Page Continuation (72) Inventor Nakashi Nakata 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Daiji Takahashi 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Incorporated (72) Inventor Masahiko Ito 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (5)

[Claims] 1. A light source for illuminating an object to be read and a transparent dust-proof member are provided at a predetermined position of a substantially sealed casing-type device body, the reading window being opened. The object to be read is illuminated by this light source, and the reflected light from the object to be read is imaged on the line sensor from the dust-proof transparent member through at least one reflecting mirror and lens arranged in the apparatus body. An image reading device for converting an electric signal to read an image, wherein the reading surface and the dust-proof surface of the dust-proof transparent member guide the reflected light from the object to be read to the lens side. An image reading apparatus, which is arranged so as to be parallel to each other in a light flux and face each other, and is configured to satisfy the following condition (1). (1) 0.1 × Lg <DL × Lo × N where Lg is the length along the optical axis between the object to be read and the dust-proof surface of the transparent member Lo: Air along the optical axis of the object to be read and the lens Converted optical path length DL: Effective diameter of front lens of lens N: Refractive index of transparent member 2. The image reading apparatus according to claim 1, wherein the light source and the dust-proof transparent member are integrally formed into one unit while the light beam from the light source is provided on the light source side. A first reflector for reflecting the object to be read is provided, and a light beam that has passed through the transparent member from the light source is reflected again to the object to be read on a surface other than the reading surface and the dustproof surface of the dust-proof transparent member. An image reading apparatus comprising a second reflector for controlling the image reading apparatus. 3. The image reading device according to claim 1, wherein a reflection mirror surface is formed on another surface of the optical path passing through the reading surface and the dustproof surface of the dustproof transparent member. . 4. The image reading apparatus according to claim 1, wherein a cleaning brush is movably provided above the dust-proof surface of the dust-proof transparent member at a position where the reading light path and the illumination light path are not blocked. An image reading apparatus characterized in that the dust-proof surface of the transparent member is cleaned by moving the transparent member. 5. The image reading apparatus according to claim 1, wherein an air injection pipe is arranged at a position above the dust-proof surface of the transparent dust-proof member so as not to block the reading light path and the illumination light path, and the air injection pipe is injected. An image reading apparatus characterized in that the dust-proof surface of the transparent member is cleaned with air.