JPH10319297A - Image pickup lens with illumination optical system, and image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact image pickup lens with an illumination optical system which is simply constituted, easily assembled and whose optical function is improved, and to provide an image pickup device. SOLUTION: The image pickup device is provided with an illumination optical system for irradiating the surface on which information is printed of a card-like medium 4 with code information printed, that is, a surface with an image to be picked up, with the illuminating light for information reading, and the device is provided with an image pickup lens 16 for forming the image of the light reflected by the surface with the information printed(surface with image to be picked up) on the image pickup surface of the image pickup device. The illuminating optical system is provided with four illuminating lenses 18 which are integrally formed with the image pickup lens 16 at the peripheral part of the image pickup lens 16, and the image pickup lens with an illumination optical system, that is, an integrated type lens is constituted of the illuminating lenses 18 and the image pickup lens 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination optical system in which, for example, an imaging lens for forming an image of reflected light from an imaging target surface and an illumination optical system for causing illumination light to enter the imaging target surface are integrally formed. The present invention relates to an imaging lens and an imaging device using the lens.

[0002]

2. Description of the Related Art Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 6-231466, an image reading apparatus used to read coded information from a dot code obtained by coding image information, audio information, character information, etc. The coded information is read by irradiating the dot code printing surface with illumination light and imaging the reflected light from the dot code printing surface with an imaging device.

In an optical microscope apparatus, for example, when illumination light is illuminated from the periphery of an objective lens through a light guide or a ring illumination system, the reflected light from the object is imaged, so that the image of the object is captured. Observations are being made.

In the above two devices, optical components such as an imaging lens and an illumination lens or an illumination mirror are:
Each is provided independently and fixed to a separate lens frame or the like (first conventional technique).

[0005] Further, an imaging device having a lighting device is conventionally known. When an imaging target surface is illuminated by using this imaging device, the illuminance is maximized at the center of the illumination area and is increased at the peripheral portion. Fall gradually as you go. Therefore, in this imaging device, the peripheral direction is made brighter by adjusting the illumination direction using, for example, an illumination direction adjustment mechanism (second related art).

[0006] Further, an imaging device in which an illumination system and an imaging system are integrated has been known, and this imaging device is provided inside the lens frame of the imaging lens so that the imaging lens and the illumination lens can be shared. A light source for illumination is arranged on the step formed in (3rd prior art).

[0007]

However, in the first prior art, it is necessary to arrange the imaging lens and the illumination lens separately. For this reason, the size of the lens-mounting lens frame is increased, and the space for mounting the imaging system is increased, which causes a problem that it is difficult to reduce the size of the apparatus. Furthermore, since lenses are required as many as the number of illumination light sources, not only the number of parts is increased but also the number of assembly steps is increased, which causes a problem that the manufacturing cost of the apparatus is increased.

In the second and third prior arts, the optical axis of the lens must be adjusted at the time of assembling the apparatus, and if the mounting accuracy of the lens is poor, the illuminance becomes uneven and the optical axis becomes uneven. There is a problem that it is difficult to maintain the performance at a constant level.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a compact imaging optical system with an optical system having a simple structure and excellent optical performance which can be easily assembled. It is to provide a lens and an imaging device.

[0010]

In order to achieve the above object, an imaging lens with an illumination optical system according to the present invention comprises an illumination light for irradiating illumination light emitted from an illumination light source to a surface to be imaged. When the illumination optical system, illumination light is irradiated on the imaging target surface, the imaging optical system includes an imaging lens for imaging the reflected light reflected from the imaging target surface at a predetermined position, the illumination optical system, It is characterized by being formed integrally with the periphery of the imaging lens.

Further, the image pickup apparatus of the present invention provides an illumination light source, an illumination optical system for irradiating the illumination light emitted from the illumination light source to the imaging target surface, and irradiating the illumination light to the imaging target surface. At this time, an imaging lens for imaging the reflected light reflected from the imaging target surface at a predetermined position, and the reflected light imaged by the imaging lens are received and converted into an electric signal corresponding to the amount of received light. A photoelectric conversion element, and a lens frame capable of integrally holding the illumination light source, the illumination optical system, the imaging lens, and the photoelectric conversion element, and the illumination optical system It is characterized by being molded integrally with the peripheral portion of the lens.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an imaging lens with an illumination optical system and an imaging apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 1 (a) and 1 (b), an image pickup apparatus 2 according to the present embodiment has, for example, a bar code or dot code of image information, character information, voice information, or the like on one side. It is provided in a reader 6 for reading a card-shaped medium 4 (for example, a paper card) on which information is printed.

The imaging device 2 includes a guide shaft 8 provided in a direction orthogonal to the feeding direction Y of the card-shaped medium 4.
Along the arrow X direction.

The imaging device 2 is fixed to an endless timing belt 12 stretched between a pair of rollers 10, and the timing belt 12 is moved in a predetermined direction by a belt driving device (not shown). It is configured to be able to control the movement of the imaging device 2 in the direction of the arrow X by running only.

The reader 6 has an opening 14 extending over the moving range of the image pickup device 2 at a position facing the image pickup device 2 so that the card-shaped medium 4 can be opened. , The code information printed on the card-shaped medium 4 can be read by the imaging device 2 through the opening 14. Specifically, the card-like medium 4 is moved by the image pickup device 2 in the direction of the arrow X along the guide shaft 8 while the card-like medium 4 is carried by the carrying mechanism (not shown) of the reader 6. The imaging process is performed on the code information printed on the.

As shown in FIGS. 2 and 3A, the image pickup device 2 irradiates the information printing surface of the card-shaped medium 4 on which the code information is printed, that is, the image pickup object surface, with illumination light for reading information. And an imaging lens 16 for imaging reflected light reflected from the information printing surface (imaging target surface) on the imaging surface of the imaging device 2.

The illumination optical system applied to the present embodiment includes:
A plurality (in the present embodiment, for example, 4
Illuminating lens 18, and the illuminating lens 18 and the imaging lens 16 constitute an imaging lens with an illuminating optical system of the present embodiment, that is, an integral lens. The peripheral portion is defined as a portion outside the effective imaging range of the imaging lens 16.

In the integrated lens applied to the present embodiment, the four illumination lenses 18 are arranged at substantially constant intervals concentrically with respect to the center of the imaging lens 16, that is, the optical axis 16a. More specifically, the angle R formed by the straight lines connecting the center of each illumination lens 18, that is, the optical axis 18 a and the optical axis 16 a of the imaging lens 16 is equal (see FIG. 3A). .

The integral lens is entirely formed of, for example, plastic, and the imaging lens 16 and the illumination lens 18 are formed in a virtual plane 20 orthogonal to the respective optical axes 16a, 18a. ing.

Such an integrated lens includes first and second mounting portions 24 formed at one end of a lens frame 22 of the imaging device 2.
26. Specifically, the imaging lens 16 is attached to the first attachment portion 24, and the illumination lens 18 is attached to the second attachment portion 26. Then, the imaging lens 16 and the illumination lens 1
8 is attached to the first and second attachment portions 24 and 26 so that optical effects such as flare can be prevented. As a result, the first and second mounting portions 24 and 26 are connected to the imaging lens 16 and the illumination lens 1.
8 also serves as a light-shielding wall for optically shutting off the light-shielding member 8. The lens frame 22 is formed of a black plastic material (for example, polycarbonate).

On the other hand, a solid-state image sensor 30 such as a CCD is attached to an attachment portion 28 formed at the other end of the lens frame 22, and an image pickup surface (not shown) of the solid-state image sensor 30.
Corresponds to the imaging position of the imaging lens 16.

An aperture 32 is integrally formed on the lens frame 22 between the solid-state image sensor 30 and the integral lens.

The lens frame 22 faces the respective illumination lenses 18 so as to irradiate the information printing surface (the surface to be imaged) of the card-shaped medium 4 with illumination light via the respective illumination lenses 18. The illumination light source 34 is attached at the position thus set.

As the illumination light source 34 of the present embodiment, for example, a light emitting diode (LED), an incandescent lamp, a light bulb, a fluorescent tube, or the like can be applied.

Next, the operation of this embodiment will be described.

The illumination light emitted from each illumination light source 34 is:
After passing through the corresponding illumination lens 18, the reader 6
The light is condensed on the information printing surface (imaging target surface) of the card-shaped medium 4 through the opening 14 (see FIG. 1).

The distribution of the amount of illumination light, that is, the illuminance distribution, of the illuminating light applied to the information printing surface (the surface to be imaged) is slightly reduced at the peripheral portion as compared with the center of the imaging, but the information printing surface (illumination) has a substantially uniform illuminance. Illumination light can be applied to the imaging surface (see FIG. 2D).

At this time, the reflected light reflected from the information printing surface (imaging target surface) passes through the imaging lens 16 and then forms an image on the imaging surface of the solid-state imaging device 30 via the stop 32.

The solid-state image sensor 30 is configured to output an electric signal corresponding to the amount of received light.
Code information is read from the card-shaped medium 4 based on the electric signal output from the solid-state imaging device 30.

The transmittance of the imaging lens 16 is slightly lower at the peripheral portion than at the lens center (optical axis 16a) (see FIG. 2C). For this reason, the solid-state imaging device 30
The light amount distribution of the reflected light imaged on the imaging surface of, that is, the illuminance distribution,
The peripheral portion is lower than the center of the imaging surface (see FIG. 2B). However, there is no problem in reading the code information.

According to the imaging lens with an optical system for illumination and the imaging apparatus of the present embodiment, since the illumination lens 18 and the imaging lens 16 are integrally formed, the number of assembly steps can be reduced. Can be simplified.

Also, the illumination lens 18 and the imaging lens 1
By integrally molding 6, it is possible to prevent the occurrence of a positional shift between the imaging range and the illumination range when assembling the lens, and to improve the strength of the imaging device 2.

Further, since the imaging lens 16 and the illumination lens 18 can be completely separated by the first and second mounting portions 24 and 26, the illumination light is
6 can be prevented from directly entering. As a result, it is possible to remove optical effects such as flare.

The illumination lens 18 is connected to the imaging lens 1.
6, the imaging surface of the imaging device 2 can be used effectively, and
Since the required optical performance for illumination can be individually set, it is possible to always irradiate the optimum illumination light to the information printing surface (the imaging target surface) of the card-shaped medium 4.

In addition, by arranging the illumination lenses 18 at substantially constant intervals, it is possible to irradiate a uniform amount of illumination light to the information printing surface (the surface to be imaged) of the card-shaped medium 4.

Further, the illumination light source 34 and the solid-state imaging device 30
Is integrally attached to one lens frame 22,
The size of the entire apparatus can be reduced and the manufacturing cost can be reduced.

The present invention is not limited to the above-described embodiment, but can be variously modified without adding new matters.

The material of the integrated lens can be arbitrarily selected and used as long as it is a transparent material. For example, glass can be used. In addition, the aperture 32 is not limited to the case where the aperture 32 is formed integrally with the lens frame 22. For example, an aperture member may be separately attached to the lens frame 22. Further, the material of the lens frame 22 can be arbitrarily selected and used as long as it is a material having a light-shielding property. For example, aluminum whose surface is subjected to black alumite treatment can be used. Furthermore, a CCD is used as the solid-state imaging device 30.
Instead of this, it is also possible to apply a line sensor other than a photoelectric conversion element such as a CMD or an area sensor.

The illumination optical system includes an illumination lens 18.
For example, a prism 36 as shown in FIG. 3B, an embedded mirror 38 as shown in FIG. 4, or a polarizing plate or a diffraction grating can be applied. .

Next, an imaging lens with an illumination optical system and an imaging apparatus according to a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. Note that the imaging device of the present embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

As shown in FIG. 5A, in the imaging lens with the illumination optical system according to the present embodiment, that is, in the integral lens, the imaging lens 16 and the illumination lens 18 are respectively provided with the optical axis 16a and the optical axis 16a. The shaft 18a is positioned and arranged so as to connect the intersection P with the card-shaped medium 4 on the side opposite to the integrated lens. Since other configurations are the same as those of the imaging lens with the optical system for illumination according to the first embodiment,
The description is omitted.

Next, the operation of this embodiment will be described.

The illumination light emitted from each illumination light source 34 is:
After passing through the corresponding illumination lens 18, the reader 6
The light is condensed on the information printing surface (imaging target surface) of the card-shaped medium 4 through the opening 14 (see FIG. 1).

In the present embodiment, the distribution of the amount of illumination light, that is, the illuminance distribution, of the illuminating light applied to the information printing surface (the surface to be imaged) is higher at the periphery than at the center of the image. The information printing surface (the surface to be imaged) can be irradiated with illumination light so as to be bright (see FIG. 5D).

At this time, the reflected light reflected from the information printing surface (imaging target surface) passes through the imaging lens 16 and forms an image on the imaging surface of the solid-state imaging device 30 via the stop 32.

The transmittance of the imaging lens 16 is slightly lower at the periphery than at the center of the lens (optical axis 16a) (see FIG. 5C). For this reason, the solid-state imaging device 30
The light amount distribution of the reflected light imaged on the imaging surface of, that is, the illuminance distribution,
A uniform state is obtained from the center of the imaging surface to the peripheral portion (see FIG. 5B).

According to the imaging lens and the imaging apparatus with the illumination optical system of the present embodiment, the illumination light emitted from the illumination light source 34 can be used for the information printing surface (the imaging object) by tilting the illumination lens 18. It is possible to irradiate efficiently and uniformly from the center of the (surface) to the peripheral portion. As a result, the number of illumination light sources 34 can be further reduced, so that the miniaturization of the apparatus and the reduction in manufacturing cost can be further improved.

Further, since the illuminance on the imaging surface of the solid-state imaging device 30 can be made uniform, the reading accuracy can be further improved.

The other effects are the same as those of the first embodiment, and the description is omitted.

The present invention is not limited to the above-described second embodiment, but can be variously modified without adding new matters.

The illumination light source 34 and the illumination lens 18
The illumination light source 34 may be attached in parallel with the optical axis 16a of the imaging lens 16, for example.

The intersection P between the optical axis 16a of the imaging lens 16 and the optical axis 18a of the illumination lens 18 is located on the card-shaped medium 4 or at a position closer to the integrated lens than the card-shaped medium 4. The same operation and effect as described above can be achieved. Therefore, according to this modified example, the following specific effects can be obtained.

That is, when the intersection point P is located on the card-shaped medium 4 or at a position closer to the integrated lens side than the card-shaped medium 4, the illuminance distribution on the information printing surface (imaging target surface) of the card-shaped medium 4 is centered. To a uniform state over the periphery.
In addition, since the illumination light is applied obliquely to the information printing surface (the imaging target surface), the reflected light travels in a direction away from the imaging lens 16. As a result, regular reflection in the direction of the imaging lens 16 is less likely to occur, so that the reading accuracy can be further improved. Further, when the intersection point P is further separated from the information printing surface (the imaging target surface), the illuminance distribution on the imaging surface of the solid-state imaging device 30 can be further uniformed, so that the shading correction can be simplified. The effect that it can be achieved can be realized.

The present specification includes the following inventions.

(1) An illumination optical system for irradiating illumination light emitted from an illumination light source to an imaging target surface, and a reflection light reflected from the imaging target surface when the illumination light is applied to the imaging target surface. An imaging lens for forming an image at a predetermined position, wherein the illumination optical system is formed integrally with a peripheral portion of the imaging lens. Lens.

(Structure) The present invention corresponds to all embodiments, that is, the first and second embodiments.

The plane to be imaged is defined as the first and second embodiments of the invention.
In the embodiment of the present invention, the information printing surface of the card-shaped medium 4 is applicable, and the light source 34 for illumination may be, for example, a light emitting diode (LED), an incandescent lamp, a light bulb, a fluorescent tube, or the like. is there. In the first and second embodiments of the present invention, the illumination optical system corresponds to a plurality (for example, four in each embodiment) of illumination lenses 18. The illumination optical system includes a prism 36 as shown in FIG. 3B and an embedded mirror 3 as shown in FIG.
8, or a polarizing plate, a diffraction grating, or the like can be applied.

(Operation) The illumination light emitted from the illumination light source is applied to the surface to be imaged through the illumination optical system. At this time, the reflected light reflected from the imaging target surface is imaged at a predetermined position (for example, an imaging surface of an imaging device) by the imaging lens.

(Effect) By integrally molding the illumination optical system and the imaging lens, the mounting space for the lens can be reduced, so that the overall size of the apparatus can be reduced. Furthermore, since the number of parts can be reduced, the number of assembling steps can be reduced.
Further, it is possible to prevent the occurrence of a problem such as a flare due to the adjustment of the lens assembly, so that the optical performance can be improved.

(2) The imaging lens with an illumination optical system according to the above (1), wherein the peripheral portion is defined at a portion outside the effective imaging range of the imaging lens.

(Structure) The present invention corresponds to all embodiments, that is, the first and second embodiments.

(Operation) The illumination light emitted from the illumination light source is applied to the imaging target surface via an illumination optical system arranged at a peripheral portion outside the effective imaging range of the imaging lens. At this time, the reflected light reflected from the imaging target surface is imaged at a predetermined position (for example, an imaging surface of an imaging device) by the imaging lens.

(Effect) By arranging the illumination optical system outside the effective imaging range of the imaging lens, the imaging surface of the imaging device can be used effectively, and the required illumination optical system can be used. Since the performance can be set individually, it is possible to always irradiate the optimal illumination light to the imaging target surface.

(3) The imaging with illumination optical system according to the above (1), wherein a plurality of the illumination optical systems are arranged at substantially constant intervals around the imaging lens. Lens.

(Structure) The present invention corresponds to all embodiments, that is, the first and second embodiments.

The substantially constant interval means that the angles formed by the straight lines connecting the center of the imaging lens and each illumination optical system are substantially the same.

(Operation) Illumination light emitted from the illumination light source is radiated to the surface to be imaged through a plurality of illumination optical systems arranged at substantially constant intervals around the imaging lens. At this time, the reflected light reflected from the imaging target surface is imaged at a predetermined position (for example, an imaging surface of an imaging device) by the imaging lens.

(Effect) By arranging the illumination optical systems at substantially constant intervals, the illumination light can be uniformly illuminated on the surface to be imaged, so that the imaging accuracy can be improved.

(4) The illumination optical system is provided with an illumination lens capable of condensing illumination light emitted from the illumination light source on the imaging target surface. 2. The imaging lens with an illumination optical system according to item 1.

(Structure) The present invention corresponds to all embodiments, that is, the first and second embodiments.

(Operation) The illumination light emitted from the illumination light source is condensed on the surface to be imaged through the illumination lens integrally formed around the imaging lens. At this time, the reflected light reflected from the imaging target surface is imaged at a predetermined position (for example, an imaging surface of an imaging device) by the imaging lens.

(Effect) Since the light (diffused light) emitted from the illumination light source is positively condensed by the optical action of the illumination lens, it is possible to efficiently irradiate the imaging target surface. As a result, it is possible to irradiate with a small number of light sources and a light source with a small output without wasting light emission power.

(5) The illumination optical system has a predetermined inclination at the periphery of the imaging lens so that the optical axis of the illumination optical system and the optical axis of the imaging lens intersect at a predetermined position. The imaging lens with the illumination optical system according to (1), wherein the imaging lens is integrally formed at an angle.

(Structure) The present invention corresponds to the second embodiment of the present invention.

As shown in FIG. 5A, the imaging lens 1
6 and the illumination lens 18 are positioned and arranged such that the respective optical axes 16a and 18a connect the intersection P on the opposite side of the card-shaped medium 4 from the integrated lens.

(Operation) When illumination light is applied to the imaging target surface via the illumination optical system, the illuminance distribution on the imaging target surface is higher at the peripheral portion than at the imaging center, and therefore, is higher than at the center. The periphery becomes brighter.

(Effect) By tilting the illumination optical system, the illumination light emitted from the illumination light source can be efficiently and uniformly irradiated from the center of the imaging target surface to the peripheral portion. As a result, since the number of illumination light sources can be further reduced, it is possible to further improve the miniaturization of the apparatus and the reduction in manufacturing cost. Further, since the illuminance on the imaging surface of the imaging device can be made uniform, the reading accuracy can be further improved.

(6) The illuminating optical system is arranged such that the optical axis of the illuminating optical system and the optical axis of the imaging lens connect an intersection on the opposite side of the imaging lens with respect to the imaging target surface. The above-mentioned (1), wherein the optical system is integrally formed at a predetermined inclination angle around the imaging lens.
2. The imaging lens with an illumination optical system according to item 1.

(Structure) The present invention corresponds to the second embodiment of the present invention.

As shown in FIG. 5A, the imaging lens 1
6 and the illumination optical system (illumination lens 18) such that the respective optical axes 16a and 18a connect the intersection P on the opposite side of the imaging lens 16 with respect to the imaging target surface, that is, the card-shaped medium 4. Are positioned.

(Function) When the illumination light is applied to the imaging target surface via the illumination optical system, the illuminance distribution on the imaging target surface is higher at the peripheral portion than at the imaging center, and therefore, is higher than at the center. The periphery becomes brighter.

(Effect) By tilting the illumination optical system, the illumination light emitted from the illumination light source can be efficiently and uniformly irradiated from the center of the imaging target surface to the peripheral portion.

(7) An illumination light source, an illumination optical system for irradiating illumination light emitted from the illumination light source to the imaging target surface, and an illumination optical system for irradiating the illumination light to the imaging target surface. An imaging lens for imaging the reflected light reflected from the imaging lens at a predetermined position, a photoelectric conversion element that receives the reflected light imaged by the imaging lens, and converts the reflected light into an electric signal corresponding to the amount of received light; An illumination light source, the illumination optical system, a lens frame capable of integrally holding the imaging lens and the photoelectric conversion element are provided, and the illumination optical system is provided at a peripheral portion of the imaging lens. An imaging device, which is integrally formed.

(Structure) The present invention corresponds to all the embodiments, that is, the first and second embodiments.

The image-capturing object plane is defined as the first and second embodiments of the present invention.
In the embodiment of the present invention, the information printing surface of the card-shaped medium 4 is applicable, and the light source 34 for illumination may be, for example, a light emitting diode (LED), an incandescent lamp, a light bulb, a fluorescent tube, or the like. is there. In the first and second embodiments of the present invention, a plurality of (for example, four in each embodiment) illumination lenses 18 correspond to the illumination optical system. The illumination optical system includes a prism 36 as shown in FIG. 3B and an embedded mirror 3 as shown in FIG.
8, or a polarizing plate, a diffraction grating, or the like can be applied. In the first and second embodiments of the present invention, the photoelectric conversion element is a solid-state imaging device such as a CCD.
Although 0 corresponds, for example, a line sensor other than a photoelectric conversion element such as a CMD or an area sensor can be applied.

(Operation) The illumination light emitted from the illumination light source is applied to the surface to be imaged through the illumination optical system. At this time, the reflected light reflected from the imaging target surface is imaged on the imaging surface of the photoelectric conversion element of the imaging device by the imaging lens. Then, an imaging process is performed on the imaging target surface based on the electric signal output from the photoelectric conversion element.

(Effect) By integrally holding the illumination light source, the illumination optical system, the imaging lens, and the photoelectric conversion element in a lens frame, it is possible to reduce the size and cost of the entire apparatus. Becomes

(8) The lens and the illumination optical system are attached to predetermined positions by abutting the mirror frame at the boundary between the area of the imaging lens and the area of the illumination optical system. The imaging device according to the above (7), wherein a possible mounting portion is provided.

(Structure) The present invention corresponds to all embodiments, that is, the first and second embodiments.

The mounting portions correspond to the first and second mounting portions 24 and 26 formed at one end of the lens frame 22 of the imaging device 2 in the first and second embodiments of the present invention. The imaging lens 16 is mounted on the first mounting portion 24, and the illumination lens 18 is mounted on the second mounting portion 26.

(Function) By attaching the imaging lens and the illumination optical system to the mounting portion, optical effects such as flare are prevented.

(Effect) At the time of assembling the apparatus, the illumination optical system and the imaging lens can be attached in one operation, so that the assembling accuracy can be improved and the trouble such as optical axis alignment can be omitted. Furthermore, the strength of the device is improved.

(9) The imaging device according to (8), wherein the mounting portion also serves as a light shielding wall for optically blocking the imaging lens and the illumination optical system.

(Structure) The present invention corresponds to all the embodiments, that is, the first and second embodiments.

(Operation and Effect) By attaching the imaging lens and the illumination optical system to the mounting portion, the imaging lens and the illumination optical system can be completely separated from each other. Direct incidence can be prevented. As a result, it is possible to remove optical effects such as flare.

[0097]

According to the present invention, it is possible to provide a compact imaging lens having an optical system for illumination and a compact imaging apparatus having a simple structure and excellent optical performance which can be easily assembled.

[Brief description of the drawings]

FIG. 1A is a perspective view schematically showing an appearance of an imaging device according to a first embodiment of the present invention, and FIG. 1B is an internal view of the imaging device shown in FIG. FIG. 2 is a perspective view showing a configuration.

FIG. 2A is a partial cross-sectional view schematically illustrating a configuration of an imaging lens with an illumination optical system according to a first embodiment of the present invention, and FIG. FIG. 3C is a diagram illustrating an illuminance distribution, FIG. 3C is a diagram illustrating a transmittance distribution of an imaging lens, and FIG. 3D is a diagram illustrating an illuminance distribution on an imaging target surface.

FIG. 3A is a plan view schematically illustrating a positional relationship of an illumination lens with respect to an imaging lens, and FIG. 3B is a diagram illustrating a configuration of an imaging lens with an illumination optical system according to a modification of the present invention. FIG.

FIG. 4A is a perspective view showing a configuration of an imaging lens with an illumination optical system according to another modification of the present invention, and FIG. 4B is an illumination optical system shown in FIG. FIG. 2 is a side view of the system-equipped imaging lens.

5A is a partial cross-sectional view schematically illustrating a configuration of an imaging lens with an illumination optical system according to a second embodiment of the present invention, and FIG. FIG. 3C is a diagram illustrating an illuminance distribution, FIG. 3C is a diagram illustrating a transmittance distribution of an imaging lens, and FIG. 3D is a diagram illustrating an illuminance distribution on an imaging target surface.

[Explanation of symbols]

 4 Card-shaped medium 16 Imaging lens 18 Illumination lens

Claims (3)

[Claims] An illumination optical system for irradiating illumination light emitted from an illumination light source to a surface to be imaged, and, when illumination light is applied to the surface to be imaged, reflected light reflected from the surface to be imaged is predetermined. An imaging lens for forming an image at a position, wherein the illumination optical system is formed integrally with the periphery of the imaging lens for imaging with an illumination optical system. lens. 2. The illumination optical system has a predetermined inclination angle at a peripheral portion of the imaging lens so that an optical axis of the illumination optical system and an optical axis of the imaging lens intersect at a predetermined position. The imaging lens with an optical system for illumination according to claim 1, wherein the imaging lens is integrally formed with the lens. 3. An illumination light source, an illumination optical system for irradiating illumination light emitted from the illumination light source to an imaging target surface, and an illumination optical system for illuminating the illumination light onto the imaging target surface. An imaging lens for imaging the reflected light at a predetermined position, and receiving the reflected light imaged by the imaging lens,
A photoelectric conversion element for converting an electric signal corresponding to a received light amount; and a lens frame capable of integrally holding the illumination light source, the illumination optical system, the imaging lens, and the photoelectric conversion element. An imaging apparatus, wherein the illumination optical system is integrally formed around a periphery of the imaging lens.