JP2001174218A - Micro visual sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro visual sensor having a new lens constitution and having high resolution, which is suitably available for a CCD camera or the like. SOLUTION: Plural microlens 13 and plural photoreceptors 14 are formed, so as to be faced to each other on transparent substrates 11 and 12. Then, the substrate 11 or 12 is moved in the X direction, Y direction, or XY directions, so that the plural microlens and the plural photoreceptors can be relatively moved. Then, plural position information is made incident on and received by the photoreceptors through microlens 13-1, so that resolution can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro vision sensor, and more particularly, to a micro vision sensor which can be suitably used for a CCD camera or the like.

[0002]

2. Description of the Related Art In a conventional camera equipped with a visual sensor, a photoreceptor 2 such as a CCD is arranged behind a single lens 1 as shown in FIG. By receiving light, an image as position information was obtained. In a solid-state imaging device for an image scanner or the like, instead of using such a single lens, in order to obtain a wide light receiving surface, a plurality of microlenses are used. A plurality of photoreceptors are arranged.

[0003]

However, in order to sufficiently increase the amount of light per pixel, that is, one photoreceptor in the lens configuration shown in FIG. 1, it is necessary to increase the aperture angle of the lens 1. There is. In order to increase the aperture angle of the lens 1, the diameter of the lens 1 must be increased. Since the focal length of the lens is about the diameter of the lens, using a lens with a large diameter requires a thickness in the optical axis direction that is approximately the same as the lens diameter.
Therefore, when using a lens configuration as shown in FIG. 1 and increasing the amount of light per photoreceptor to obtain a camera with high resolution, only a camera long in the optical axis direction can be obtained.

On the other hand, in a lens configuration in which a plurality of microlenses and a plurality of photoreceptors are arranged so as to face each other, such as a solid-state imaging device, a microlens having a small diameter is used, so Can be reduced in length. However, in such a lens configuration, the resolution is determined by the density of the fixed microlens and photoreceptor. Therefore, in such a lens configuration, the resolution can be improved by reducing the size of the microlens and the photoreceptor and increasing their density. However, since the microlens has a diffraction limit determined by the wavelength of light and the like, a limitation accompanying the diffraction limit is imposed in miniaturizing the microlens. For this reason, a sufficiently high resolution cannot be obtained even with such a lens configuration. Further, when the photoreceptors are integrated at a high density, the amount of received light per pixel decreases, and the sensitivity decreases. For this reason, there is a limit in increasing the sensitivity of the photoreceptor.

[0005] The present invention has a novel lens configuration,
It is an object of the present invention to provide a micro vision sensor having a high resolution that can be suitably used for a D camera or the like.

[0006]

In order to achieve the above object,
The first micro vision sensor of the present invention includes a plurality of micro lenses and a plurality of photo receptors, and arranges the plurality of micro lenses and the plurality of photo receptors so as to face each other. The plurality of microlenses are moved relative to the plurality of photoreceptors.

In a state where the microlens and the photoreceptor are fixed to face each other as in the solid-state image pickup device or the like, each photoreceptor has a single position obtained through each lens disposed to face each other. Only information comes in. On the other hand, in the micro vision sensor of the present invention, the plurality of micro lenses and the plurality of photo receptors are relatively moved without being fixed to each other. Therefore, the relative positional relationship between the microlens and the photoreceptor changes with time. Since one position information is obtained in one position relationship between the microlens and the photoreceptor, as described above, these position relationships relatively change with time,
A plurality of position information can be obtained.

For example, when light transmitted through a lens is incident on an opposing photoreceptor and a certain portion of a predetermined object is obtained as an image, the light from the predetermined object is incident on the microlens at various angles. . The light incident on the microlens is refracted at various angles according to the angle of incidence, and passes through the microlens. In the state where the microlens and the photoreceptor are fixed,
Only light within a certain range of the light refracted in this way can be received. Therefore, only a certain part of the predetermined object can be obtained as an image.

On the other hand, when the relative position between the microlens and the photoreceptor is changed, the light refracted as described above can be received in a considerable range. Therefore, a considerable portion of the predetermined object can be obtained as an image. That is, according to the micro visual sensor of the present invention, for a part of the image of the predetermined object corresponding to a single piece of position information, a considerable portion of the predetermined object corresponding to a plurality of pieces of position information Image can be obtained.

As described above, according to the present invention, since the micro visual sensor can obtain a plurality of pieces of position information, its resolution can be extremely increased. Furthermore, since the lens in the micro visual sensor is composed of a plurality of micro lenses, the length in the optical axis direction can be reduced. Therefore, a thin micro visual sensor can be provided.

A second micro visual sensor according to the present invention includes a plurality of micro lenses and a plurality of photo receptors, and arranges the plurality of micro lenses and the plurality of photo receptors so as to face each other. I do. Then, a slit plate having a plurality of slits is provided between the plurality of microlenses and the plurality of photoreceptors. The plurality of microlenses, the plurality of photoreceptors, and the plurality of slits are arranged so as to face each other. Then, at least one or two components selected from the component groups of the plurality of microlenses, the plurality of photoreceptors, and the slit plate are relatively moved with respect to other components of the component group. .

The second micro-visual sensor includes a slit plate having a plurality of slits between a plurality of micro-lenses and a plurality of photo-receptors in order to provide directivity to position information from the micro-lens to the photo-receptor. Provided. In such a case, the above-described effects can be obtained by causing relative movement between these components. That is, when these components are fixed, only a single position information based on a single directivity can be obtained, but the directivity changes by moving the components relative to each other, and accordingly, A plurality of pieces of position information can be obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments of the present invention. FIG. 2 is a schematic diagram showing a lens configuration in an example of the first micro visual sensor of the present invention. FIG. 2A is a perspective view of a lens configuration,
FIG. 2B is a cross-sectional view when the lens configuration shown in FIG. 2A is cut by a plane including the line II. In the lens configuration shown in FIG. 2, a plurality of microlenses 13 and a plurality of photoreceptors 14 are formed on transparent substrates 11 and 12 so as to face each other.

In such a lens configuration, the substrate 11 on which a plurality of microlenses 13 are formed and the substrate 12 on which a plurality of photoreceptors are formed are relatively moved in an X direction or a Y direction, and further in an XY direction. By moving the microlens 13 in one direction, a plurality of pieces of position information are incident on one of the plurality of photoreceptors 14, for example, 14-1 facing the microlens through one of the plurality of microlenses 13, such as 13-1. Then, as compared with a case where only a single position information is obtained when the plurality of microlenses 13 and the plurality of photoreceptors 14 are fixed to each other, the position information is several times to several tens times the same lens configuration. Can be easily obtained. Therefore, the resolution of the micro visual sensor can be dramatically improved.

The case where the plurality of microlenses 13 and the plurality of photoreceptors 14 are relatively moved in the X direction will be specifically described with reference to the sectional view of the lens configuration shown in FIG. 2B. For example, assuming that the microlens 13-1 is fixed at a position facing the photoreceptor 14-1, the microlens 1 is attached to the photoreceptor 14-1.
Through 3-1 only single position information P such as an image of a certain part of a predetermined object is obtained. On the other hand, the microlens 13-1 is moved to the left and right so that 13A
And 13-1B, position information Q and R different from the position information P are obtained by the refraction of the microlens 13-1.

That is, while only a single piece of positional information P was obtained when the microlens 13-1 and the photoreceptor 14-1 were fixed, a plurality of relative position Location information P, Q, and R
Is obtained. Therefore, since the resolution of the lens configuration is increased, a micro visual sensor having excellent resolution can be obtained. It should be noted that the number of pieces of position information can naturally be increased from P, Q, and R depending on the degree of relative movement.

FIG. 3 is a schematic diagram showing a lens configuration in an example of the second micro visual sensor according to the present invention. FIG.
3A is a cross-sectional view of the lens configuration, and FIG. 3B is a plan view of the lens configuration. In the lens configuration shown in FIG. 3, a plurality of microlenses 23 and a plurality of photoreceptors 24 are disposed on transparent substrates 21 and 22 so as to face each other. Then, a slit plate 25 having a plurality of slits 26 is provided between the plurality of microlenses 23 and the plurality of photoreceptors 24.
Further, the slit plate 25 is arranged so that the plurality of microlenses 23, the plurality of photoreceptors 24, and the plurality of slits 26 face each other. As described above, the slit plate 25 is used for giving directivity to position information.

Also in this case, at least one of the plurality of microlenses 23 and the slit plate 25 is moved in the X direction, the Y direction, the XY direction, or the rotation direction indicated by the arrow S with respect to the plurality of photoreceptors 24, for example. , A plurality of pieces of position information can be obtained as compared with the case where these are fixed. That is, higher resolution can be obtained with the same lens configuration than when a plurality of micro lenses 23 and the like are fixed, and a micro visual sensor having excellent resolution can be obtained. Also, a plurality of position information can be obtained as described above by relatively moving the plurality of microlenses 23 and the slit plate 25.

When the micro lens is relatively moved,
For example, a plurality of pieces of position information can be obtained based on the principle shown in FIG. When the slit plate and the photoreceptor are relatively moved, the number of position information directly obtained by the microlens does not change, but the directivity of the position information obtained through the slit changes, and as a result, the The number of location information to be received will increase.

As described above, the first micro vision sensor of the present invention moves the plurality of micro lenses relative to the plurality of photo receptors. Therefore, a plurality of photoreceptors are fixed and a plurality of microlenses are moved, or a plurality of microlenses are fixed and a plurality of photoreceptors are moved to perform the relative movement as described above. Can be. Also,
The second micro visual sensor of the present invention moves one or two components of the plurality of microlenses, the slit plate, and the plurality of photoreceptor components relative to the remaining components. Therefore, by fixing one or two of these components and moving the other components, the above relative movement becomes possible.

Among the plurality of microlenses, the plurality of photoreceptors, and the slit plate, the mass of the slit plate is the smallest. Therefore, in the second micro visual sensor having the slit plate, the relative movement can be performed with a smaller driving force by moving the slit plate. Further, the slit plate can be vibrated at a relatively high frequency, and the number of relative movements per unit time increases. Therefore, the resolution per short time, that is, the resolution of the entire lens configuration can be improved.

In the lens configuration of the second micro visual sensor shown in FIG. 3, a single slit plate 2 is provided between a plurality of micro lenses 23 and a plurality of photo receptors 24.
Only 5 are provided. However, the number of slit plates is not limited to one.

For example, the slit plate is composed of a first slit plate and a second slit plate, and a plurality of slits provided in these slit plates are opposed to each other, and a plurality of micro lenses and a plurality of photoreceptors are opposed to each other. To be placed. Then, the first slit plate and the second slit plate are moved relatively to the plurality of photoreceptors. Further, the first slit plate and the second slit plate are moved in different directions. Then, the first
Since the slit plate and the second slit plate move in different directions with respect to the plurality of photoreceptors, a plurality of pieces of position information can be obtained two-dimensionally at the same time.

In this case as well, a plurality of microlenses and a plurality of photoreceptors are fixed, and a first slit plate and a second slit plate are attached to the plurality of microlenses and the plurality of photoreceptors. By causing relative movement, relative movement can be performed with a small driving force, and the resolution of the lens configuration can be improved.

In the lens configuration of the micro vision sensor of the present invention shown in FIGS. 2 and 3, the micro lens and the photoreceptor are formed isotropically at equal intervals. However, when it is desired to obtain an image of a specific portion of a predetermined object in a wide range, that is, when it is desired to obtain a large number of specific position information, the microlens density and the photoreceptor density or the slit width of such a portion are increased. Then, a microlens and a photoreceptor are arranged.

In the micro visual sensor of the present invention,
The microlens can be formed using a known method. For example, a method in which a thin film made of a light-transmitting inorganic material or a light-transmitting organic material is directly formed by micromachining, a method in which a predetermined mold is formed by an electroforming method and the like, and a lens is formed in the mold, It can be obtained by a method of patterning a film, melting it by heating, and cooling and solidifying a spherical photoresist rounded by surface tension. Further, as the photoreceptor, a known light receiving element such as a photodiode or a phototransistor can be used. Further, the slit plate can be formed from silicon, a silicon compound such as silicon nitride and silicon oxide, aluminum, chromium, or polyimide.

The substrate on which the microlenses and the photoreceptor are formed is not particularly limited, and can be made of any kind of material. However, it is preferred that the substrate is made of a plastic material. Thereby, the micro visual sensor of the present invention having the lens configuration as shown in FIGS. 2 and 3 can be easily formed on an arbitrary surface such as a curved surface or an uneven surface. Examples of such a plastic material include silicone rubber and polyimide. In addition, the thickness of the substrate is arbitrarily set according to the shape and state of the surface forming the micro visual sensor and the type of the plastic substance.

The plurality of pieces of position information obtained by the photoreceptor causes the arithmetic circuit to temporarily store a single piece of position information constituting the plurality of pieces of position information as a function of time allocated to the single piece of position information. . Thereafter, by performing predetermined arithmetic processing, position information can be extracted again from the time portion and reconstructed, and the plurality of position information can be obtained linearly, two-dimensionally, or three-dimensionally.

The relative movement between the plurality of microlenses and the plurality of photoreceptors is preferably performed using a microactuator. Thereby, the relative motion can be performed with extremely fine precision. Examples of the microactuator include an electromagnetic actuator, an electrostatic actuator, a thermal stress actuator, and an electrostrictive actuator.

As described above, the present invention has been described in detail based on the embodiments of the present invention with specific examples. However, the present invention is not limited to the above contents, and the present invention is not limited thereto. All modifications and changes are possible.

[0031]

As described above, according to the micro vision sensor of the present invention, a plurality of micro lenses or slit plates are caused to move relative to a plurality of photoreceptors. , More position information can be obtained. Therefore, it is possible to obtain a high-resolution micro visual sensor with the same lens configuration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a lens configuration in an example of a conventional micro visual sensor.

FIG. 2 is a schematic diagram showing a lens configuration in an example of the first micro visual sensor of the present invention.

FIG. 3 is a schematic diagram showing a lens configuration in an example of a second micro visual sensor according to the present invention.

[Explanation of symbols]

 1, lens 2 photoreceptor 11, 12, 21, 22 substrate 13, 13-1, 13-2, 23 micro lens 14, 14-1, 14-2, 24 photoreceptor 25 slit plate 26 slit

Claims (9)

[Claims] A plurality of microlenses and a plurality of photoreceptors; a plurality of microlenses and a plurality of photoreceptors arranged so as to face each other; and positional information obtained through the plurality of microlenses. A plurality of micro-lenses are received by the plurality of photoreceptors, the plurality of microlenses are relatively moved with respect to the plurality of photoreceptors, and a plurality of pieces of position information are provided in each of the plurality of photoreceptors. A micro visual sensor, characterized in that: A plurality of microlenses and a plurality of photoreceptors, wherein the plurality of microlenses and a plurality of photoreceptors are arranged so as to face each other, and positional information obtained through the plurality of microlenses. A plurality of microlenses and a plurality of slits having a plurality of slits between the plurality of photoreceptors, wherein the plurality of microlenses and the plurality of photoreceptors are provided. A lens, the plurality of photoreceptors and the plurality of slits are arranged so as to face each other, and the plurality of microlenses, the plurality of photoreceptors, and one or two selected from the component group of the slit plate. Move the component relative to other components of the component group. , Characterized in that to obtain a plurality of position information in each of the plurality of photoreceptor, micro vision sensor. 3. The micro-micrometer according to claim 2, wherein said slit plate is vibrated to perform relative movement between said slit plate, said plurality of microlenses and said plurality of photoreceptors. Vision sensor. 4. The slit plate includes a first slit plate and a second slit plate, and the first slit plate and the second slit plate are formed such that a plurality of slits provided respectively overlap with each other. And the first slit plate and the second slit plate are moved relative to the plurality of microlenses and the plurality of photoreceptors, and the first slit plate and the second
3. The micro visual sensor according to claim 2, wherein the plurality of slit plates are moved in directions different from each other, and the plurality of pieces of position information are simultaneously and two-dimensionally obtained in each of the plurality of photoreceptors. 4. 5. The first slit plate and the second slit plate are vibrated, and the first slit plate and the second slit plate, the plurality of micro lenses and the plurality of photoreceptors are vibrated. The micro visual sensor according to claim 4, wherein the relative motion of the micro visual sensor is performed. 6. The micro-device according to claim 1, wherein the plurality of micro-lenses and the plurality of photo-receptors are formed on a substrate made of a plastic material, respectively. Vision sensor. 7. The micro vision sensor according to claim 6, wherein the plastic material is at least one of silicone rubber and polyimide. 8. A plurality of position information is stored in a predetermined arithmetic circuit as a function of time corresponding to each of the single position information constituting the plurality of position information, and then subjected to predetermined arithmetic processing. The position information is obtained again from the time portion by this.
The micro visual sensor according to any one of the above. 9. The micro visual sensor according to claim 1, wherein the relative movement is performed using a micro actuator.