JPH11316822A - Optical reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent strong imprinting in the periphery of an object even at the time of receiving the reflected light from the object by a wide angle lens. SOLUTION: An optical reader is provided with an irradiation means 33, which irradiates an objects 13 through an optical transparent body 2, and an optical read means 4 having a lens group 41 as lenses to take in an image of the object 13 through the optical transparent body 2. In this case, a lens holding frame 56 which holds the lens group 41 is provided with a visual field mask 37 which limits the range of the image from the object 13 passing the optical transparent body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an optical reader. More specifically, the present invention relates to a field mask that determines the field of view of a subject for image reading.

[0002]

2. Description of the Related Art There is an optical reading apparatus for reading an image of a subject by irradiating a subject with a light beam and taking in the reflected light. This optical reader 100 is, for example, shown in FIG.
As shown in FIG. 15, for example, a large number of LEDs 103 for irradiating light to the subject 102 via an optical transparent body 109 made of sapphire glass, and a lens group 104 for capturing an image of the subject 102 via the optical transparent body 109 And an imaging element 105. The lens group 10
A light detecting member 107 formed of, for example, a phototransistor for detecting that the subject 102 exists on the upper surface of the optically transparent body 109 is provided on a side portion of the light transmitting member 109.

When an image of a subject 102 such as a coin is read by the optical reading apparatus 100, the subject 102 is slid on an optically transparent body 109. Light detection member 10
When it is detected that the subject 102 is at a predetermined position on the optically transparent body 2 by the LED 7, the LED 103 emits light and reading of the image is started. Then, as shown in FIG. 16, the light beam emitted right above the LED 103 is refracted by the prism 106 to the inside of the main body 108. The light beam passes through the opening 110 of the main body 108, passes through the optically transparent body 109, irradiates the subject 102, and is reflected. The reflected light passes through the optically transparent body 109 and passes through the opening 1.
10 and enters the lens group 104 and enters the image sensor 10
5 is imaged. Thus, the image of the subject 102 is captured by the image sensor 105 and converted into an electric signal.

In FIG. 16, reference numeral 111 denotes a ring-shaped light-shielding member, which forms a dark field frame 112 read by the lens group 104.

By the way, in order to reduce the size of the optical reader 100 in order to expand its use, the lens group 1
It is conceivable to use a wide-angle lens as 04. In this case, since the light receiving angle of the lens group 104 is widened and the focal length is short, the optically transparent body 109 and the image sensor 105
Can be reduced to reduce the size of the optical reader 100.

[0006]

However, in the optical reader using the above-described wide-angle lens, since the distance between the optically transparent body 109 and the image pickup device 105 is short, extra light rays due to internal reflection are generated in the object 102. There is a possibility that the surrounding area may be illuminated and the area is strongly reflected on the image sensor 105. When such reflection occurs, it is difficult to determine the image of the subject 102, and the reading accuracy may be reduced. For example, when a coin is used as the subject 102, an error may occur in the measurement of the coin diameter.

In order to prevent such reflection, the inner peripheral edge of the light-shielding member 111 is extended inward as shown in FIG. It is conceivable that the field frame 113 ′ is narrowed by the member 111. However, if such a light-shielding member 111 whose inner peripheral edge is extended inward is used, the light path from the light detection member 107 to the subject 102 is blocked, so that such a light-shielding member 111 cannot be provided.

Further, the installation position of the light detection member 107 is limited to a predetermined range depending on the size of the subject 102 and the like.
The light detection member 107 cannot always be provided at a position where the light detection member 107 does not interfere with the light shielding member 111 whose inner peripheral edge is extended inward.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical reader capable of preventing strong reflection around a subject even when reflected light from the subject is received by a wide-angle lens.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, there is provided an irradiating means for irradiating a subject via an optically transparent body and capturing an image of the subject via the optically transparent body. An optical reading device having a lens for holding a lens, wherein a lens holding frame for holding the lens is provided with a visual field mask for limiting a range of an image from a subject via an optically transparent body. ing.

Therefore, since the visual field mask is provided on the lens holding frame, the visual field mask is largely out of focus near the lens and is hardly affected by internal reflection, so that the reflected light from the object is received by the wide-angle lens. In this case, the reflection of the field frame formed by the field mask on the optical reading means can be suppressed to an extremely low level. Moreover, since the visual field mask is provided on the lens holding frame, the visual field mask itself can be made smaller than before.

Further, in the optical reading apparatus according to the second aspect, a circular opening is provided in the holding frame to which the optically transparent body is attached, and a passage through which a subject to be image-read passes through the outside of the optically transparent body. And irradiating means are provided inside the optically transparent body so as to surround the opening, and a circular opening for cutting the reflected light from the irradiating means other than the opening is provided in the visual field mask. .

[0013] Therefore, since the light beam reflected by the portion other than the opening of the holding frame is cut by the edge of the circular opening of the field mask, only the light beam reflected by the opening of the holding frame can be taken into the optical reading means. it can.

Further, in the optical reading apparatus according to the third aspect, a light detecting member for detecting passage of a subject is provided near the optical reading means, and the outer edge of the field mask is moved from the light detecting member to the optical axis of the optical reading means. Side. Therefore, it is possible to prevent the optical axis of the light detection member from interfering with the field mask, so that the field frame can be formed by the field mask while the light detection member is provided.

Further, in the optical reader according to the fourth aspect, the irradiating means is constituted by arranging a large number of light emitting elements in a circular shape around the opening of the holding frame, and irradiating light from the large number of light emitting elements. Is reflected by the reflecting surface to illuminate the subject with dark field. Therefore, the irradiating means can uniformly irradiate the subject evenly over the entire circumference, and can darken a portion other than the subject. Therefore, only the image of the subject can be raised in the image read by the optical reading unit and the contrast thereof can be made uniform, so that the reading accuracy of the image can be improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail based on an example of an embodiment shown in the drawings. 1 to 12 show an embodiment of the optical reader 1 of the present invention. The optical reading device 1 includes an irradiating unit 33 that irradiates the subject 13 via the optical transparent body 2,
And an optical reading means 4 having a lens group 41 which is a lens for taking in an image of the subject 13 through the lens. In the present embodiment, the optical reading device 1 is
The pattern of the coin is read and used to determine the type and authenticity of the coin. However, the application of the optical reader 1 is not limited to coin reading.

In the optical reader 1, as shown in FIG. 1, a field mask 37 for limiting the range of an image from the subject 13 via the optically transparent body 2 is provided on a lens holding frame 56 for holding the lens group 41. Is provided. Therefore, the field mask 37 is largely out of focus near the lens group 41 and is hardly affected by internal reflection in the optical reader 1, so that the field frame formed by the field mask 37 can be read by the optical reading means 4. Can be suppressed extremely low. Accordingly, the unevenness of the subject 13 can be clearly recognized, and the reading accuracy of the image can be improved. Moreover, since the field mask 37 is provided on the lens holding frame 56,
The field mask 37 is replaced with a conventional field mask 111 shown in FIG.
Can be smaller than Therefore, the visual field mask 3
7 can be obtained at low cost.

Further, in the optical reader 1, a circular opening 50 is provided in the holding frame 14 on which the optical transparent body 2 is mounted, so that the subject 13 whose image is to be read passes outside the optical transparent body 2. The irradiation means 33 is provided inside the optically transparent body 2 so as to surround the opening 50. In the present embodiment, a light emitting element composed of a large number of LEDs is used as the irradiation means 33. However,
It goes without saying that the light emitting element of the irradiation means 33 is not limited to the LED.

An opening 50 is formed in the field mask 37.
A circular opening 37a for cutting the reflected light from the irradiating means 33 is provided. For this reason, the light rays reflected from portions other than the opening 50 of the holding frame 14
7 is cut by the edge of the opening 37 a, so that only the light beam reflected by the opening 50 of the holding frame 14 can be taken into the optical reading unit 14.

Further, the optical reading means 4 takes in the reflected light from the subject 13 which is transmitted through the optical transparent body 2 and forms an image by taking in the reflected light from the subject 13, and converts the formed image into an electric signal. And an image pickup device 42 formed of, for example, a CCD. The imaging device 42 is mounted on a CCD substrate 43 fixed to the main body frame 3.

A lens holding frame 56 for holding the lens group 41
A lens frame 35 for directly holding the lens group 41;
Frame 36 for holding the lens with respect to the body frame 3
And The lens frame 36 is the body frame 3
It is formed integrally with. Here, the lens group 41
As a wide-angle lens. For this reason, the focal length of the lens group 41 can be shortened, so that the distance between the optically transparent body 2 and the image sensor 42 can be shortened, and the optical reader 1 can be reduced in size and weight. The object 13 is provided on the side of the lens frame 36 with the optically transparent body 2.
There is provided a light detecting member 38 for detecting the presence of the light detecting member on the upper surface of the light emitting element. The light detection member 38 is configured by a phototransistor in the present embodiment.

A field mask 37 is attached to the upper surface of the lens frame 36 by, for example, bonding. For this reason, the mounting work of the visual field mask 37 can be performed easily and inexpensively. The field mask 37 is annular and has a lens group 4
1 light path. Opening 37 of this field mask 37
The edge of “a” prevents the peripheral portion of the optically transparent body 2 from being reflected.

Here, the shape, size, and mounting position of the field mask 37 are such that the outer edge of the field mask 37 is a light detecting member 38.
It is located closer to the optical axis side of the optical reading means 4. For this reason, the optical axis of the light detection member 38 is
Therefore, the function of detecting the subject 13 by the light detection member 38 and the function of preventing the surroundings of the subject 13 from being reflected by the field mask 37 can be achieved.

On the other hand, in the optical reader 1, the optical transparent body 2 is formed in a circular shape having a diameter larger than that of the opening 50 as shown in FIG. The optically transparent body 2 is supported by the main body frame 3 so as to be located at the center of the upper part of the optical reader 1 and is supported by the holding frame 14 which forms a part of the main body 15. An annular visual field mask 54 is provided at the center of the holding frame 14.
A circular opening 50 is formed by the inner edge of the opening. By the way, the opening 50 is formed by providing the field mask 54 on the holding frame 14. The field frame in the lens group 41 is formed by the field mask 37 attached to the lens holding frame 56. For this reason, in this embodiment, the field mask 54 is provided on the holding frame 14, but this field mask 54 may be eliminated by making the holding frame 14 the same shape as the field mask 54 is attached to. In the present embodiment, the optical transparent body 2 has a circular shape. However, the present invention is not limited to this, and the optical transparent body 2 may have a rectangular shape positioned from one end to the other end of the optical reader 1.

Since the optical transparent body 2 has a circular shape, the optical transparent body 2 can have a minimum necessary area, and is optically transparent as compared with the conventional rectangular optical transparent body 109. The cost of the body 2 can be reduced. Therefore, the cost of the optical reader 1 can be reduced. In addition, since the optical transparent body 2 is circular, there is no portion that causes stress concentration. For this reason, the strength of the optical transparent body 2 can be improved.
Can be prevented from cracking in the optically transparent body 2 even if it falls. Therefore, the reading accuracy of the image does not decrease due to the cracks in the optical transparent body 2, and there is no need to replace the optical transparent body 2.

As shown in FIG. 1 to FIG. 6, before and after the optical transparent body 2 in the passing direction D of the subject 13, passage members 34, 34 having an outer shape along the peripheral surface of the optical transparent body 2 are provided. Are located. Each passage member 34 is plate-shaped and has an arc-shaped concave portion 34 a that matches the outer edge of the optically transparent body 2.
The passage member 34 is supported by the holding frame 14 in a state where the concave portion 34a is aligned with the peripheral surface of the optically transparent body 2. The passage 32 of the subject 13 is formed by the optically transparent body 2 and the passage members 34, 34. For this reason,
Since the passage 32 is formed by the optical transparent body 2 and the passage members 34, 34, the subject 1 is
Even if the passage member 34 falls and the passage member 34 is cracked, the crack does not propagate to the optically transparent body 2. Therefore, the reading accuracy of the image does not decrease due to the cracks in the optical transparent body 2, and there is no need to replace the optical transparent body 2.

The optically transparent body 2 is made of sapphire glass. For this reason, since the optical transparent body 2 can have a high hardness, even if the object 13 which is a metal coin is slid on the optical transparent body 2, the optical transparent body 2 is not worn or scratched. Can be suppressed. Moreover, the optically transparent body 2
Can be made high in strength, so that the occurrence of destruction or damage due to dropping of the subject 13 or the like can be suppressed. Furthermore, the optical transparent body 2 is a circular sapphire glass plate, and since the same optical transparent body 2 is used in the technical field of a timepiece or the like, the technology and equipment for mass production are widespread. Therefore, this optically transparent body 2 can be manufactured at low cost.

The material of the passage member 34 is not particularly limited, but is made of metal in the present embodiment. For this reason, since the passage member 34 can have high hardness, even when the subject 13, which is a metal coin, slides on the passage member 34, it is possible to prevent the passage member 34 from being worn or damaged. In addition, since the strength of the passage member 34 can be increased, it is possible to prevent the subject 13 from being broken or damaged due to dropping or the like. Further, by repeatedly sliding the subject 13 in the passage 32, the passage member 34 is
Can be prevented.

In this embodiment, the passage member 34 is made of SUS30.
4 made of non-magnetic stainless steel subjected to a surface hardening treatment. Here, since the SUS 304 is non-magnetic, for example, even if the subject 13 is a magnetic material having magnetism, the passage member 34 is not charged and magnetized by sliding on the passage member 34. Therefore, metal dust or the like generated by the friction between the subject 13 and the passage member 34 attached to the subject 13 does not adhere to the passage member 34 by magnetic force and stay there. Powder or the like can be prevented from being caught between the subject 13 and the optically transparent body 2.

Further, in this embodiment, the surface of the passage member 34 that contacts the subject 13 is subjected to a surface hardening treatment. The method of the surface hardening treatment is not particularly limited, and for example, an existing or new method such as a nitriding treatment or a carbonization treatment can be adopted. Therefore, the wear resistance and scratch resistance of the passage member 34 against the subject 13 can be further improved.

In this embodiment, the passage member 34 is subjected to the surface hardening treatment, but is not limited to this, and may not be subjected to the surface hardening treatment. Further, in the present embodiment, the passage member 34 is made of SUS304, but is not limited to this, and may be made of a super hard material such as SK material. Further, in this embodiment, the passage member 34 is made of a non-magnetic metal, but is not limited to this, and may be made of a metal made of a magnetic material. In any case, the passage member 34 is made to have a high hardness so that the passage member 3
4 can be prevented from being worn or scratched, and the passage member 34 can be made to have high strength to prevent the breakage and scratching.

Further, in this embodiment, the passage member 34 is made of metal, but is not limited to this, and may be made of, for example, glass or plastic. In any case, the passage member 34 can be manufactured at low cost. Moreover, passage 3
2 is composed of the optical transparent body 2 and the passage members 34, 34, so that even if the passage member 34 is cracked, the propagation of the crack to the optical transparent body 2 can be prevented. In particular, when the passage member 34 is made of plastic, each passage member 34,
34 and the optical transparent body 2 can be integrally formed by molding, so that the optical reader 1 can be easily assembled. Moreover, since the passage member 34 can be made non-magnetic, it is possible to prevent metal powder and the like from adhering to the passage member 34.

Further, the optically transparent body 2 and the passage members 34, 3
4 at the edges of the subject 13 in the passing direction D,
The tapered surfaces 2a and 34b are formed. Specifically, the entire peripheral edge on the front side of the optical transparent body 2 is chamfered to form a tapered surface 2.
a. Further, the concave portion 34a of the passage member 34 and the surface side of the edge facing the concave portion 34a are chamfered to form a tapered surface 34b.
Is formed. Therefore, when the subject 13 slides in the passage 32, it is possible to prevent the subject 13 from being caught on the edges of the optically transparent body 2 and the passage members 34, 34. For this reason, the subject 13 can be slid smoothly,
Clogging can be prevented.

On the other hand, on the surface of the optical transparent body 2 opposite to the surface facing the subject 13, an anti-reflection film 48 for preventing reflection of light having a wavelength different from that of the irradiation light of the irradiation means 33 is provided. . Here, the inventors of the present application have found that the antireflection can be effectively performed in some cases by making the peak wavelength of the antireflection film 48 different from the wavelength of the irradiation unit 33. In this embodiment, since the antireflection film 48 has a peak wavelength different from the peak wavelength of the irradiation light of the irradiation unit 33, the irradiation light generated by the irradiation unit 33 Internal reflection inside can be suppressed. As a result, it is possible to suppress the occurrence of ghost and flare in the image read by the optical reading unit 4. For this reason, the accuracy of the determination of the read image can be improved.

In this embodiment, the irradiating means 33 comprises:
Approximately 950 by using LEDs that emit infrared light
It has a peak wavelength of nm. Further, the antireflection film 48 provided on the inner side surface of the optically transparent body 2 is formed by coating the optically transparent body 2 with magnesium fluoride. In the present embodiment, the antireflection film 48
Is formed by coating with magnesium fluoride, but the present invention is not limited to this, and an existing or new material used as an antireflection film can be used.

The peak wavelength of the anti-reflection film 48 can be adjusted by the thickness of the film. In this embodiment, the thickness of the anti-reflection film 48 is about 60
The thickness is set to have a peak wavelength of about 0 nm. Therefore, the irradiation means 33 and the antireflection film 48
By setting the peak wavelength, the internal reflection at the optical reader 1 can be suppressed. In the present embodiment, the peak wavelength of the irradiation means 33 is set to about 950 nm and the peak wavelength of the antireflection film 48 is set to about 600 nm. However, the present invention is not limited to this, and the wavelengths of the irradiation means 33 and the antireflection film 48 are made different. Just do it. That is, the irradiation unit 33
By making the peak wavelength of the antireflection film 48 different, the internal reflection in the optical reader 1 can be suppressed. In particular, in the present embodiment, a wide-angle lens is used as the lens group 41, so that the internal reflection is likely to be strong. Can be done.
In the present embodiment, the peak wavelength of the antireflection film 48 is different from the wavelength of the irradiation unit 33, but the present invention is not limited to this, and the lengths of the respective wavelengths may be equal. Further, in the present embodiment, the anti-reflection film 48 is provided on the optically transparent body 2. However, the present invention is not limited to this, and the anti-reflection film 48 may not be provided.

The irradiating means 33 includes the optical reader 1
Is supported by the main body frame 3 via an LED board 49. A plurality of irradiation means 33 are arranged in a circular shape so as to surround the opening 50 of the optically transparent body 2, that is, the field frame. L
An annular prism 51 that covers the upper side of the irradiation unit 33 is attached to the ED substrate 49. This prism 51
Is transmitted and reflected so that the light beam of the irradiation unit 33 irradiated upward is radiated obliquely to the opening 50 from the outer peripheral side. For this reason, the circular opening 50 is illuminated by the irradiating means 33 arranged in a circular shape around the circular opening 50 and the subject 13 is illuminated in the dark field.
3 can be evenly radiated over the entire circumference, and the portion other than the subject 13 can be completely darkened. For this reason, only the image of the subject 13 in the image read by the optical reading means 4 can be raised to make the contrast uniform, so that the reading accuracy of the image can be improved.

Further, the light beam emitted from the prism 51 passes through the diffusion plate 55 and irradiates the optically transparent body 2. For this reason, the optically transparent body 2 can be uniformly irradiated. Then, the light beam from the irradiating unit 33 passes through the optically transparent body 2 and irradiates the subject 13, and the reflected light passes through the optically transparent body 2 and is taken into the optical reading unit 4.

On the other hand, the optical reading device 1 comprises an optical reading means 4 for taking in data inside the device via the optical transparent body 2.
And a circuit body 12 for operating the optical reading means 4 therein. Case body 5
Is formed so as to seal the optical path between the optical reading means 4 and the optically transparent body 2 and the optical reading means 4 and the circuit section 12. In the present embodiment, the circuit section 12 has two circuit boards, and the optical reading means 4 has a lens group 41, an image sensor 42, and a CCD board 43. Then, the lens groups 41 and C of the optical reading means 4
The optical reading means 4 and the circuit section 12 are fixed by fixing the CD substrate 43 and the substrate of the circuit section 12 to the main body frame 3 and fixing the optically transparent body 2 to the main body frame 3 via the holding frame 14. The body frame 3, the holding frame 14, and the optically transparent body 2 are integrated as a whole to form a body portion 15.

The case body 5 is made of metal and has a rectangular parallelepiped shape whose upper side is opened. The case body 5 and the main body 15 are attached by fitting the open edge 53 of the case body 5 to the step 6 on the outer periphery of the holding frame 14 of the main body 15.

In the optical reader 1, the connector for electrically connecting the circuit section 12 to the outside of the case body 5 is provided with the packing member 17 on the packing support section 17 located around the externally exposed section 19 of the connector section. 18 is formed by the unit body 16 attached thereto. In addition, case body 5
The bottom 20 is formed with an opening 21 formed of a through hole for exposing the externally exposed portion 19 to the outside of the case body 5.
In the present embodiment, the opening 21 is formed in the bottom portion 20 of the case body 5, but is not limited to this, and the side portion 52 of the case body 5
May be formed. In the present embodiment,
The connector portion is formed by the unit body 16 in which the packing member 18 is attached to the packing support portion 17, but is not limited thereto.

Further, the unit body 16 is fixed to the case body 5 such that the externally exposed portion 19 is exposed to the outside through the opening 21 and the packing member 18 is pressed between the case body 5 and the packing support portion 17. It is fixed inside. The packing member 18 is made of an elastic material such as rubber, and in the present embodiment, has a plate shape having a through hole in the center. As this packing member 18, commercially available O
A ring or the like may be used.

For this reason, the connector is connected to the packing member 18.
The connector can be attached to and detached from the case body 5 with a general-purpose screw member or the like. Thus, the case body 5 can be easily removed from the main body 15 without using a dedicated jig. Further, since the packing member 18 is sandwiched and pressed between the case body 5 and the packing support part 17, the sealing performance between the case body 5 and the connector part can be improved, and the connection between the case body 5 and the connector part can be improved. Sealing can be performed without using a sealing agent therebetween. For this reason,
When removing the case body 5 from the main body frame 3, the sealant between the connector portion and the case body 5 is not broken, so that generation of dust and dust can be prevented. Moreover,
Since no sealant is used between the case body 5 and the connector portion, the appearance can be improved, and it is not necessary to carefully apply the sealant while paying attention to the deterioration of the appearance, so that the workability of assembly is eliminated. Can be improved.

Here, the unit body 16 includes a connector socket 19 to which an external connector of the case body 5 connectable to the connector portion is connected and also forms an externally exposed portion, and a connector to be connected and fixed to the connector socket 19. Substrate 2
2, a holder 23 for fixing the connector socket 19 and the connector board 22 to the case body 5 and having a packing support portion 17, and a packing member 18 attached to the packing support portion 17 on the outer periphery of the connector socket 19. The holder 23 includes a receiving hole 24 for receiving the connector socket 19, a concave packing support portion 17 formed at an edge of the receiving hole 24 on a surface facing the inner surface of the case body 5 and receiving the packing member 18, Substrate 2
A board fixing hole 26 for screwing the holder 2 to the holder 23 with a bolt 25, and a bolt 27 from the outside of the case body 5.
And a holder fixing hole 28 for screwing the holder 23 to the case body 5.

The connector socket 19 is connected and fixed to the connector board 22 by soldering. The connector board 22 to which the connector socket 19 is fixed is screwed to the holder 23 with the connector socket 19 housed in the housing hole 24 of the holder 23. Here, a sealant 29 is applied to the contact portion between the holder 23 and the connector board 22 from the outer peripheral side. As the sealant 29, for example, an adhesive made of a synthetic resin can be used. Therefore, sealing can be performed between the holder 23 and the connector board 22.

Further, a packing member 18 is provided so as to surround the outer periphery of the connector socket 19. The packing member 18 is housed in the packing support 17. Then, the holder 23 is screwed to the case body 5 from the outside of the case body 5 with the distal end of the connector socket 19 being exposed from the inside of the case body 5 through the opening 21 to the outside. For this reason, the case body 5 and the holder 2
The sealing member 18 can be squashed between the sealing member 3 and the sealing member 3 to achieve sealing. Moreover, since the packing member 18 is provided on the outer periphery of the connector socket 19, the gap between the connector socket 19 and the packing member 18 can be sealed.

The connector board 22 and the circuit section 12 are connected by, for example, a flexible cable 30. One end of the flexible cable 30 is directly soldered to the connector board 22, and the other end is connected to the board of the circuit section 12 via the cable socket 31.

Here, when the holder 23 is pressed inward from the outside of the main body 15, the holder 23 comes into contact with the circuit section 12 fixed to the main body frame 3 and the optical reading means 4 to be outside the main body 15. It keeps you from entering inside while it is located. More specifically, the holder 23 is
Circuit board and body frame 3 of the circuit portion 12 fixed to the
The optical reading means 4 is fixed to the CCD substrate 43 of the optical reading means 4 in a loose state. Further, the connector board 22 is disposed so as to enter the inside of the CCD board 43. Therefore, when the connector board 22 comes into contact with the CCD board 43 from the inside, the unit body 16 is
5 can be prevented from falling off. For this reason, since the holder 23 is positioned by the substrates 12 and 43, workability can be improved when the case body 5 is put on the main body 15 and the holder 23 is screwed.

On the other hand, a step 6 is formed on the outer peripheral surface of the holding frame 14. The open edge 53 of the case body 5 is fitted into the step 6. And the case body 5
The contact surface 6a of the step portion 6 against which the open edge 53 of the step body abuts is perpendicular to the outer peripheral surface of the case body 5. This allows
The positioning of the case body 5 can be performed reliably. Further, the stepped portion 6 does not need to be continuously provided so as to make a round around the main body frame 3, but only needs to be provided within a necessary and sufficient range for positioning the case body 5.

In this embodiment, as shown in FIGS. 2 and 11, the step 6 is formed by cutting out the step at the center of each of a pair of facing sides, so that the case The grounding part 11 is located. However, it is a matter of course that the shape is not particularly limited.

On the other hand, the case body 5 is attached so as to cover the main body 15. The case body 5 in the present embodiment is made of a steel plate, and four side portions 52,.
Are bent perpendicular to 0, and these side portions 52,.
52 are joined to each other by fillet welding to form an opening at the top.

As shown in FIG.
As shown in FIG. 1 and FIG. 12, a butting portion 7 which comes into contact with the step portion 6 is provided so as to protrude upward. In this case, the butting portion 7 connects the case body 5 to the holding frame 14.
And the butting portion 7 is brought into contact with the contact surface 6a of the step portion 6.
The gap 8 is formed between the contact surface 6a and a portion other than the butted portion 7 of the open end 53 when the contact is made.

The butting portion 7 is formed in a trapezoidal shape protruding from the open end 53 of the case body 5, and the case body 5 is further fixed to the protruding portion by screwing the holding frame 14 to the holding frame 14 with a bolt 44. Screw holes 10 are provided. In this case, the four butting portions 7,..., 7 are provided so that the protruding amounts from the open edge 53 are equal at any positions, so that the case body 5 can be accurately and balancedly positioned with respect to the holding frame 14. Has been. However, the shape or form of the butting portion 7 is not limited to such a shape. For example, the shape or shape of the butting portion 7 may be a semicircle shape or a triangular shape. There is no problem as long as the gap 8 is formed between the open edge 53 of the case body 5 and the contact surface 6a of the step portion 6. Butt against the position thus positioned,
The case body 5 and the holding frame 14 are fixed by screwing the screwing portion 10 of the butting portion 7 to form the optical reading device 1.

The open end 53 of the case body 5 is provided with a ground portion 11 for grounding the case body 5. The grounding portion 11 in the present embodiment is formed integrally with the case body 5 between the adjacent butting portions 7 and 7 and has a substantially L-shape protruding from the opening edge 53 beyond the butting portion 7. In this case, the ground portion 11 has a shape that becomes thinner toward the tip, and the upper portion of the tip has a pointed shape that maintains good contact and electrical conductivity. For this reason, the ground part 11 has flexibility.

When the case body 5 is mounted on the main body frame 3 having a potential of 0 via the holding frame 14, the tip of the ground portion 11 of the case body 5 is connected to the frame of the optical apparatus to which the optical reader 1 is mounted. And so on. Since the contacted grounding portion 11 is bent and pressed against the frame or the like of the optical system device, the grounding state of the case body 5 is always maintained. Note that the shape and form of the grounding portion 11 shown here are merely examples, and are not particularly limited as long as the case body 5 can be sufficiently grounded.

A gap 8 is provided by an abutting portion 7 between the open end 53 of the case body 5 and the contact surface 6 a of the step portion 6. The gap 8 is coated with a sealant 9 for fixing the holding frame 14 and the case body 5 and improving sealing performance. In the present embodiment, a highly viscous resin curable material is used as the sealant 9. In this case, since the sealant 9 may be applied to the gap 8, the sealant 9 can be evenly applied to the shape of the gap 8 visually. The sealant 9 may be applied entirely so as to fill the gap 8 between the main body frame 3 and the case body 5, but as in the present embodiment, the open edge 5 of the case body 5
Even if it is applied only on the three sides, the sealing property between the holding frame 14 and the case body 5 can be sufficiently maintained, so that it is possible to reduce the amount of application as long as the sealing property is maintained.

Since the sealing agent 9 is applied to the outer peripheral surface of the optical reader 1 in this manner, it is suitable for removing the case body 5 from the main body 15. That is, the cured sealing agent 9 can be removed from the surrounding side by scraping or the like, so that the case body 5 can be easily removed from the main body 15.

When assembling the optical reader 1 described above, the circuit section 12 and the CCD
The unit body 16 of the connector part is attached to 3. Then, the case body 5 is put on the main body 15, and the holder 23 is screwed to the case body 5 from the outside of the bottom part 20 of the case body 5 with a bolt 27. Then, the butting portion 7 of the case body 5 is screwed to the holding frame 14 to open the edge 53.
Is applied with a sealant 9. Thereby, the optical reader 1
Is assembled.

When removing the case body 5 from the main body 15, the sealing agent 9 at the open edge 53 is removed, and the butting portion 7 and the bolts 44, 27 of the bottom portion 20 are removed. As a result, the case body 5 is no longer fixed to the main body 15, and thus can be easily removed from the main body 15.

Further, when the image of the subject 13 is taken in by the above-mentioned optical reader 1, the subject 13 is slid in the passage 32. When the light detecting member 38 detects that the subject 13 is located on the optically transparent body 2, reading of an image is started. Here, since the light detection member 38 is provided so that the optical axis does not interfere with the visual field mask 37, the subject 13 can be detected without any problem.

Then, irradiation light is generated by the irradiation means 33 and transmitted through the prism 51 and the diffusion plate 55. The transmitted light passes through the optically transparent body 2 and irradiates the subject 13 to be reflected. The reflected light passes through the optically transparent body 2 again, enters the lens group 41, and is imaged by the image pickup device 42. At this time, the reflected light from the irradiation unit 33 other than the opening 50 is cut by the edge of the opening 37a of the field mask 37, so that the reflection of the field frame around the subject 13 is suppressed and the reading accuracy is improved. be able to. The formed image is converted into an electric signal by the image sensor 42. Here, an antireflection film 48 is formed on the inner side surface of the optically transparent body 2, and the peak wavelength of the antireflection film 48 is determined by the irradiation unit 33.
, The internal reflection inside the optical reader 1 can be suppressed.

As described above, according to the optical reader 1 of the present embodiment, since the visual field mask 37 is provided on the lens holding frame 56, the visual field mask 37 is close to the lens group 41 and greatly defocused. It is hardly affected by internal reflection in the reading device 1. For this reason, even if the reflected light from the subject 13 is received by the wide-angle lens, the reflection of the field frame formed by the field mask 37 on the optical reading means 4 can be extremely suppressed.
Therefore, while reducing the size of the optical reading device 1, the unevenness of the subject 13 can be clearly recognized and the reading accuracy of the image can be improved.

In addition, the field mask 37 is mounted on the lens holding frame 5.
6, the field mask 37 can be made smaller than the conventional field mask 111. Therefore,
The field mask 37 can be obtained at low cost.

Since the field mask 37 has a circular opening 37a for cutting the reflected light from the irradiating means 33 other than the opening 50, the light reflected from the holding frame 14 other than the opening 50 is provided. Is cut by the edge of the opening 37a of the field mask 37. For this reason, since only the light beam reflected by the opening 50 of the holding frame 14 can be taken into the optical reading means 14, the unevenness of the subject 13 can be clearly recognized, and the reading accuracy of the image can be improved.

Since the outer edge of the field mask 37 is located on the optical axis side of the optical reading means 4 with respect to the light detecting member 38,
It is possible to prevent the optical axis of the light detection member 38 from interfering with the field mask 37. Therefore, the function of detecting the subject 13 by the light detection member 38 and the function of preventing the surrounding of the subject 13 from being reflected by the field mask 37 can be achieved.

In the optical reader 1 of the present embodiment, a gap 8 is formed between the step 6 and the open edge 53, and the gap 8 between the main body frame 3 and the case body 5 is formed. Is sealed with a sealing agent 9 to enhance the sealing performance. Therefore, it is possible to prevent dust from entering the inside of the optical reader 1.

In addition, the sealant 9 is used to connect the case 5 to the main body 1.
5 is applied from the outside after assembling, the amount of application can be adjusted visually, and there is no extra application. It does not protrude inside. Also,
Since the sealing agent 9 is applied later, less attention is required when assembling the case body 5 to the main body 15. In other words, when attaching the case body 5 to the main body 15 to which the sealing agent 9 has been applied in advance, the sealing agent 9 is spread over a portion where the gap 8 is formed without excess or shortage while preventing the sealing agent 9 from adhering to other portions. However, according to the present embodiment, the time required for the mounting and the time required for the application are small, and the labor required for the assembly is small.

The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the visual field mask 37 is mounted on the upper surface of the lens frame 36, but the mounting position is not limited to this. For example, the field mask 37 may be attached to the mirror frame 35 or provided as a field stop inside the lens group 41. Even in these cases, the reflection of the field frame formed by the field mask 37 onto the optical reading means 4 can be suppressed to an extremely low level, so that the unevenness of the subject 13 can be clearly recognized and the image reading accuracy can be improved. it can.

In this embodiment, the visual field mask 37 is formed in an annular shape. However, the present invention is not limited to this.
May be a shape that does not interfere with the optical axis of the light detection member 38. For this reason, the field mask 37 is, for example,
The optical axis 8 may have a cutout portion or a through hole through which the optical axis 8 passes without interference.

Further, in this embodiment, the holder 23 and the connector socket 19 are separate bodies, but the invention is not limited to this, and the holder 23 and the connector socket 19 may be integrally formed by, for example, injection molding of plastic. In this case, the number of parts decreases.

In this embodiment, the optical reader 1
Of the connector when the inside and outside of the device are connected by a connector, but the present invention is not limited to this.
A cable sealing structure may be used when the inside and outside of the cable are connected by a cable.

In this case, as shown in FIG. 13, the optical reading device 1 includes a drawer for drawing out a connection cable 45 for electrically connecting the circuit section 12 to the outside of the case body 5 from the case body 5. Unit body 1 in which packing member 18 is attached to packing support portion 17 around external exposed portion 46 of FIG.
6 '. Then, the unit body 16 ′ is fixed to the inside of the case body 5 such that the externally exposed portion 46 is exposed to the outside through the opening 21 and the packing member 18 is sandwiched between the case body 5 and the packing support part 17 and pressed against the case body 5. I do.

For this reason, since the draw-out portion is formed by the unit body 16 'including the packing member 18, the draw-out portion can be attached to and detached from the case body 5 by a general-purpose screw member or the like. Thus, the case body 5 can be easily removed from the main body 15 without using a dedicated jig. Also, since the packing member 18 is sandwiched and pressed between the case body 5 and the packing support portion 17,
The sealing performance between the case body 5 and the draw-out portion can be improved, and the sealing can be performed without using a sealing agent between the case body 5 and the draw-out portion. For this reason, when removing the case body 5 from the main body frame 3, the sealing agent between the drawer and the case body 5 is not broken, so that generation of dust and dust can be prevented. In addition, since no sealant is used between the case body 5 and the draw-out portion, the appearance can be improved, and it is not necessary to carefully apply the sealant while paying attention to the deterioration of the appearance. Workability can be improved.

Further, the unit body 16 ′ is
Having a connection cable 45 electrically connected to the outside of the device, a holding member 17 for holding and fixing the connection cable 45 to the case body 5, a concave-shaped packing support portion 17, and an externally exposed portion 46 exposed to the outside of the case body 5. 23 and the externally exposed portion 4
And a packing member 18 attached to the packing support portion 17 on the outer periphery of 6. For this reason, the connection cable 45 can be easily removed from the case body 5 and the sealing agent is not broken when the case body 5 is removed from the main body portion 15, thereby preventing generation of dust and dirt. can do. Further, a sealant 47 is applied between the connection cable 45 and the holder 23. Therefore, sealing between the connection cable 45 and the holder 23 can be performed.

In each of the above embodiments, the case where the sealing structure such as a connector is applied to an optical reader for reading a pattern such as a coin is described. However, the present invention is not limited to this. The present invention may be applied to an optical reader. Also in this case, the case can be easily removed from the main body without using a dedicated jig, and at the time of removal, generation of dust and dust can be prevented.

In each of the embodiments described above, the optical reader 1
Is used for coin reading, but is not limited to this, and can be used for fingerprint reading, for example.

[0077]

As is apparent from the above description, according to the optical reading apparatus of the first aspect, since the field mask is provided on the lens holding frame, the field mask is largely out of focus near the lens. In addition, it is hardly affected by internal reflection. For this reason, even if the reflected light from the subject is received by the wide-angle lens, the reflection of the field frame formed by the field mask on the optical reading means can be extremely suppressed. Therefore, while reducing the size of the optical reading device, the unevenness of the subject can be clearly recognized and the reading accuracy of the image can be improved. Moreover, since the visual field mask is provided on the lens holding frame, the visual field mask itself can be made smaller than before. Therefore, a visual field mask can be obtained at low cost.

Further, according to the optical reading device of the second aspect, the light beam reflected by the portion other than the opening of the holding frame is cut by the edge of the circular opening of the field mask. Only the reflected light beam can be taken into the optical reading means. Therefore, the image reading accuracy can be improved by clearly recognizing the unevenness of the subject.

Further, according to the optical reading device of the third aspect, it is possible to prevent the optical axis of the light detecting member from interfering with the visual field mask. The reflection of the field frame on the optical reading means can be kept extremely low.

Further, according to the optical reading device of the fourth aspect, the irradiating means can irradiate the object evenly over the entire circumference without evenness, and can darken a portion other than the object. . Therefore, only the image of the subject can be raised in the image read by the optical reading unit and the contrast thereof can be made uniform, so that the reading accuracy of the image can be improved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of an optical reading device of the present invention.

FIG. 2 is a plan view showing the optical reader.

FIG. 3 is a plan view showing an optically transparent body.

FIG. 4 is a side view showing an optically transparent body.

FIG. 5 is a plan view showing a passage member.

FIG. 6 is a side view showing a state where the passage member is cut along a line VI-VI in FIG. 5;

FIG. 7 is an enlarged sectional view showing a connector section of the optical reader.

FIG. 8 is a diagram showing a unit body, (A) is a front view,
(B) is a sectional view taken along line BB in (A).

FIG. 9 is a side view showing the optical reader.

FIG. 10 is a bottom view showing the optical reader.

FIG. 11 is another side view showing the optical reader.

FIG. 12 is a side view showing a case body.

FIG. 13 is an enlarged sectional view showing another embodiment of the connector section of the optical reader.

FIG. 14 is a longitudinal sectional side view showing a conventional optical reading apparatus.

FIG. 15 is a plan view showing a conventional optical reader.

FIG. 16 is a longitudinal sectional side view showing a part of a conventional optical reader.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 optical reading device 2 optical transparent body 4 optical reading means 13 subject 14 holding frame 32 passage 33 irradiation means (light emitting element) 37 field mask 37 a opening 38 light detection member 41 lens group (lens) 42 image pickup element 50 opening 56 Lens holding frame

Claims (4)

[Claims] 1. An optical reading apparatus comprising: irradiating means for irradiating a subject via an optical transparent body; and optical reading means having a lens for capturing an image of the subject via the optical transparent body. 3. The optical reading device according to claim 1, wherein a field mask for limiting a range of an image from the subject via the optical transparent body is provided on a lens holding frame holding the lens. 2. A holding frame to which the optically transparent body is attached, wherein a circular opening is provided to form a passage through which the subject whose image is to be read passes through outside the optically transparent body, and the optically transparent body. The irradiating means is provided inside the body so as to surround the opening, and the field mask is provided with a circular opening for cutting reflected light from the irradiating means other than the opening. The optical reader according to claim 1. 3. A light detecting member for detecting passage of the object is provided near the optical reading means, and an outer edge of the field mask is provided on the optical axis side of the optical reading means with respect to the light detecting member. The optical reader according to claim 1 or 2, wherein: 4. The irradiating means is configured by arranging a large number of light emitting elements in a circular shape around the opening of the holding frame, and reflecting light from the large number of light emitting elements by a reflection surface. The optical reader according to claim 2, wherein the subject is illuminated with a dark field.