JP2005164283A - Surface shape detector, optical apparatus, and manufacturing method for optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface shape detector of a small size and simple constitution, an optical apparatus, and a manufacturing method for the optical apparatus, in the surface shape detector for detecting a surface shape of a detected face by irradiating the detected face arranged opposedly to a detecting face with light, and by detecting reflected light from the detected face, the optical apparatus, and the manufacturing method for the optical apparatus. <P>SOLUTION: This surface shape detector 100 having an irradiation means 11 for irradiating the detected face arranged opposedly to the detecting face with the light, and a detecting means 13 for receiving the reflected light from the detected face to be detected has an optical element 12 layered with a plurality of light guide arrays 41 formed with a plurality of first light guides 31. In the optical element 12, one-end faces 12a in the plurality of first light guides 31 are formed and arranged to be opposed to the detected face, and the other-end faces 12b in the plurality of first light guides 31 are formed and arranged to be opposed to the detecting face of the detecting means 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surface shape detection device, an optical device, and a method for manufacturing an optical device, and in particular, irradiates light to a detection surface arranged opposite to the detection surface and detects reflected light from the detection surface. The present invention relates to a surface shape detection device that detects a surface shape of a surface to be detected, an optical device, and a method for manufacturing an optical device.

The fingerprint sensor detects unevenness of a fingerprint in order to detect a fingerprint pattern. As the fingerprint sensor, there are a semiconductor type, a pressure type, an optical type, and the like.

  The semiconductor fingerprint sensor determines unevenness from the charge amount of the matrix-like surface electrode. In addition, the pressure type fingerprint sensor obtains unevenness information corresponding to the pressure distribution as an electrical signal when a conductive substance arranged at a small interval with the matrix electrode is pressed from the detection surface and brought into contact with the matrix electrode. is there. The optical fingerprint sensor detects a surface reflectance generated by contact with a convex portion of a fingerprint or a change in diffuse reflectance as an optical signal.

  In addition, as an optical uneven | corrugated input device, the apparatus using an optical fiber bundle is proposed. In this apparatus, one end of the optical fiber bundle is arranged to face the detection surface with which the detection target comes into contact, the other end is arranged to face the light receiving surface of the photoelectric conversion means, and light is applied from the side surface of the optical fiber bundle to the detection surface. The light reflected by one end of the optical fiber bundle is guided to the light receiving surface of the photoelectric conversion means by the optical fiber bundle, and the pattern of the contact convex portion on the detection surface is identified by the photoelectric conversion means. (Patent Document 1).

JP-A-6-300930

  However, since the optical device is formed by the optical fiber bundle which bundled a plurality of optical fibers, the conventional detection device is not easy to manufacture and is difficult to reduce in size. In addition, there is a problem that the end surface with which the detection target contacts cannot be flattened.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a surface shape detecting device and an optical device as well as a manufacturing method of an optical device that are small and can be easily configured.

  The present invention provides an irradiating means (11) for irradiating light to a detected surface arranged opposite to the detecting surface, and a detecting means (13) for detecting reflected light from the detected surface by receiving it on the light receiving surface. The surface shape detection device (1) having the optical element (12) formed by stacking a plurality of light guide array (41) in which a plurality of first light guides (31) are formed, and optical The element (12) is shaped and arranged so that one end faces (12a) of the plurality of first light guide paths (31) face the detection surface (S), and the other end face of the plurality of first light guide paths (31). (12b) is shaped and arranged so as to face the light receiving surface of the detection means (13).

  The optical element (12) is formed such that one end face (12a) of the plurality of first light guide paths (31) and the other end face (12b) of the first plurality of light guide paths (31) are inclined with respect to each other. It is characterized by that.

  Further, the optical element (12) is shaped and arranged so that one end surface (12a) faces the irradiation means (11), and the other end surface (12b) faces the detection surface (S). It has a plurality of 2nd light guides (431) formed intersecting with a plurality of 1st light guides (31).

  Further, the optical element manufacturing method includes a light guide path array forming step for forming a light guide path array (41) in which a plurality of light guide paths (31) are formed in a planar shape, and a light guide path formed by a light guide path array forming procedure. A light guide block forming step for forming a light guide block formed by laminating a plurality of optical path arrays (41) and a light guide block formed by the light guide block forming procedure are cut obliquely with respect to the extending direction of the light guide (31). And a light guide path block cutting step.

  The light guide path array forming step separates the light guide paths (112, 113, 114) from the substrate (111) and the light guide path formation process of forming a plurality of light guide paths (112, 113, 114) on the substrate (111). And a light guide path separation process.

  In addition, the said reference code is a reference to the last, This does not limit a claim.

  As described above, according to the present invention, the optical element (12) is formed and arranged such that the one end faces (12a) of the plurality of first light guides (31) face the detection surface (S), and the plurality of optical elements (12) are arranged. By adopting a configuration in which the other end surface (12b) of the first light guide path (31) is shaped and arranged so as to face the light receiving surface of the detection means (13), the configuration is simple and accurate, and The optical element (12) can be configured to enable high-density detection. Further, since the pattern of the light guide path (31) can be easily changed and set, the degree of freedom in design is improved.

[First embodiment]
FIG. 1 shows a system configuration diagram of a first embodiment of the present invention.

  The surface shape detection apparatus 1 according to the present embodiment includes a light emitting unit 11, an optical device 12, a light receiving unit 13, and a processing unit 14.

  The light emitting unit 11 includes a light emitting diode and the like, and emits light in response to a signal from the processing unit 14. The light emitted from the light emitting unit 11 passes through the optical device 12 and is supplied to the detection surface S.

  An object to be detected such as a human finger contacts the detection surface S. On the detection surface S, the light from the light emitting unit 11 is reflected or absorbed by the unevenness of the fingerprint. For example, most of the light is transmitted through the portion in close contact with the detection surface S, and the light is totally reflected at the separated portion.

  The light reflected by the detection surface S enters from the incident surface of the optical device 12, passes through the optical device 12, exits from the exit surface, and is supplied to the light receiving unit 13. The light receiving unit 13 is composed of, for example, a charge coupled device (CCD), and converts light that has passed through the optical device 12 into an electrical signal. The electrical signal converted by the light receiving unit 13 is supplied to the processing unit 14.

  The processing unit 14 is configured by a microcomputer or the like, and reproduces a two-dimensional image corresponding to the unevenness of the detected object from the electric signal detected by the light receiving unit 13.

[Optical device 12]
The optical device 12 will be described.

  FIG. 3 shows a perspective view of the optical device 12.

  The optical device 12 has a configuration in which a plurality of light guide array 41 formed with a plurality of light guides 31 are stacked and fixed. In the optical device 12, the cut surface 12 a that is one end surface of the light guide path 31 and the emission surface 12 b that is the other end face of the light guide path 31 are formed at an angle of 45 °. The cut surface 12 a of the optical device 12 is a detection surface S, and the emission surface 12 b is disposed so as to be parallel to the light receiving surface of the light receiving unit 13. At this time, the light guide path 31 is linearly formed between the cut surface 12a and the emission surface 12b of the optical device 12.

[Method of Manufacturing Optical Device 12]
Here, a method for manufacturing the optical device 12 will be described.

  4 and 5 are views for explaining a method of manufacturing the optical device 12.

  First, a method for forming the light guide array 41 will be described.

  As shown in FIG. 4A, a lower cladding layer 112 is formed on a silicon substrate 111. The lower cladding layer 112 is made of, for example, a transparent resin such as an acrylic resin material. The lower clad layer 112 made of acrylic resin is formed on the silicon substrate 111 by, for example, a spin coat method.

  Next, as shown in FIG. 4B, a core 113 is formed linearly on the lower cladding layer 112 by photolithography. The core 113 constitutes the light guide path 31 and is made of the same acrylic resin material as that of the clad layer 112.

Note that the resin is adjusted so that the core 113 has a refractive index different from that of the lower cladding layer 112. For example, when the refractive index of the lower cladding layer 112 is n1 and the refractive index of the core 113 is n2,
n1 <n2
The components of the constituent resin are adjusted so that

  The core 113 is formed by first forming a transparent resin layer of acrylic resin on the clad layer 112 by spin coating or the like. Next, a photoresist is patterned on a portion where the core 113 is to be formed. At this time, as shown in FIG. 4B, the photoresist is patterned linearly in the arrow X direction.

  Next, for example, a dry etching process is performed by an RIE (reactive ion etching) apparatus or the like, and etching is performed until the lower cladding layer 112 is exposed. At this time, the photoresist forming portion is not etched, and the transparent resin layer below it remains. Next, the remaining resist is removed. Thus, the core 113 is formed as shown in FIG.

  Next, as shown in FIG. 4C, an upper cladding layer 114 is formed so as to cover the side surface and the upper surface of the core 113. The upper cladding layer 114 is made of the same acrylic resin material as the lower cladding layer 112 and is adjusted to have the same refractive index as that of the lower cladding layer 112. The upper cladding layer 114 is formed by a spin coating method or the like.

  As described above, the lower cladding layer 112 and the upper cladding layer 114 having different refractive indexes are formed around the core 113. As a result, the light incident on one end surface of the core 113 is reflected at the boundary surface between the core 113, the lower cladding layer 112, and the upper cladding layer 114 and is confined inside the core 113. As a result, the core 113 acts as the light guide path 31.

  The light guide array 41 is formed by the above manufacturing method.

  Next, after the light guide array 41 is stacked and fixed as shown in FIG. 5, it is cut along the one-dot broken line shown in FIG. An optical device 112 as shown in FIG. 3 is formed by cutting an optical block in which a plurality of light guide path arrays 41 are stacked along a dashed line. The cut surface 12a at this time becomes the detection surface S. At this time, the cut surface 12a is formed at, for example, 45 ° with respect to the end surface in the arrow X direction.

  In the manufacturing method of the optical device 12 as described above, the light guide path 31 can be freely set in pitch, width, and the like, and can be formed with high definition. Therefore, it is possible to detect the surface shape with high definition.

[Operation]
Next, the operation of the surface shape detection apparatus 1 of the present embodiment will be described.

  The processing unit 14 supplies a drive signal to the light emitting unit 11 when detecting the surface shape. The light emitting unit 11 emits light according to the drive signal from the processing unit 14. The light emitted from the light emitting unit 11 enters the optical device 12. The light incident on the optical device 12 enters the clad layers 112 and 113 and the side surfaces of the core 111 substantially orthogonally. For this reason, it reaches the cut surface 12a of the optical device 12 without being refracted much.

  For example, the finger 2 that is the detection target is in contact with the cut surface 12a of the optical device 12 that is the detection surface S. At this time, the convex portion of the finger 2 is in contact with the detection surface S, and the concave portion is in a separated state.

  The light incident on the detection surface S from the light emitting unit 11 is reflected in the extending direction of the light guide path 31 by the portion not in contact with the detection surface S, that is, the concave portion of the finger 2. The light reflected by the detection surface S is emitted from the emission surface 12 b of the optical device 12 through the light guide path 31.

  The light emitted from the emission surface 12b of the optical device 12 is received by the light receiving unit 13 provided facing the emission surface 12b.

  Therefore, on the light receiving surface of the light receiving unit 13, light is incident on a pixel portion where one end surface of the light guide 31 is opposed to the other end surface of the light guide 31 corresponding to the concave portion of the finger 2, and one end surface of the light guide 31 is Light is not incident on the pixel portion facing the other end surface of the light guide path 31 corresponding to the convex portion of the finger 2.

  Therefore, by detecting the light emitted from the light exit surface 12b of the optical device 12 by the light receiving unit 13, the uneven state of the finger 2 can be detected, and the fingerprint of the finger 2 can be detected.

〔effect〕
According to this embodiment, a plurality of light guide path arrays 41 each having a plurality of light guide paths 31 formed on a substrate 111 are stacked and then cut to form the optical device 12 whose cut surface 12a serves as a detection surface. Therefore, an optical device with high definition and easy manufacture can be provided.

  Further, since the cut surface 12a is formed by cutting a plurality of light guide path arrays 41 that are fixed, the flatness is good, and thus the detection accuracy can be improved.

[Modification]
FIG. 6 is a perspective view of a modification of the optical device 12.

  The optical device 212 of this modification is different from the optical device 12 in the configuration of each light guide array 221. The light guide path array 221 of this modification is configured by laminating the layers peeled from the substrate 111 after the clad layers 112 and 114 and the core 113 are formed on the substrate 111.

  According to this modification, since the substrate 111 does not exist, the pitch p2 of the light guide path 31 in the arrow Z direction can be reduced. As a result, when the light guides 31 are arranged in a square on the detection surface S, the pitch p1 in the arrow Y direction can also be reduced. Therefore, it is possible to increase the density of detection pixels.

[Second Embodiment]
In the present embodiment, the cut surface 12a of the optical device 12 is the detection surface S. However, a protection member may be provided on the cut surface 12a of the optical device 12 to form the detection surface S.

  FIG. 7 shows a system configuration diagram of the second embodiment of the present invention. In the figure, the same components as in FIG.

  In the surface shape detection device 300 of this embodiment, a protection member 311 is provided on the cut surface 12 a of the optical device 12.

  The protection member 311 is formed of a flat plate, for example, a transparent resin material, and is disposed in close contact with the cut surface 12 a of the optical device 12. The protective member 311 can prevent the optical device 12 from coming into direct contact with the finger 2 that is the detection target, thereby preventing the optical device 12 from being soiled or damaged by sebum. Note that the protective member 311 may be made of an inorganic material such as glass, for example.

[Third embodiment]
FIG. 8 shows a system configuration diagram of the third embodiment of the present invention. In the figure, the same components as in FIG.

  The surface shape detection device 400 of the present embodiment is different from the first embodiment in the configuration of the optical device 412.

  FIG. 9 shows a perspective view of the optical device 412. In the figure, the same components as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted.

  The optical device 412 of this embodiment is configured by laminating a plurality of light guide array 441. The light guide path array 441 is different from the first embodiment in the light guide path pattern. In addition to the light guide path 31 that guides light from the detection surface S to the light receiving portion 13, the light from the light emitting portion 11 is applied to the detection surface S. The light guide path 431 is configured to be guided.

[Method of Manufacturing Optical Device 412]
Here, a method for manufacturing the optical device 412 will be described.

  10 and 11 are views for explaining a method for manufacturing the optical device 412. FIG.

  First, a method for forming the light guide array 441 will be described.

  As shown in FIG. 10A, a lower cladding layer 112 is formed on a silicon substrate 111. The lower cladding layer 112 is made of, for example, a transparent resin such as an acrylic resin material. The lower clad layer 112 made of acrylic resin is formed on the silicon substrate 111 by spin coating or the like.

  Next, cores 413 are formed on the lower cladding layer 112 in a lattice pattern as shown in FIG. The core 413 constitutes the light guide paths 31 and 431 and is made of the same acrylic resin as that of the lower clad layer 112.

The core 413 is made of resin so that its refractive index is different from that of the lower cladding layer 112. For example, when the refractive index of the lower cladding layer 112 is n1 and the refractive index of the core 413 is n2,
n1 <n2
The constituent resin is adjusted so that

  The core 413 is formed by first forming an acrylic resin transparent resin layer on the lower clad layer 112 by spin coating or the like. Next, a photoresist is patterned on a portion where the core 113 is to be formed. At this time, the photoresist is patterned in a lattice pattern as shown in FIG.

  Next, for example, a dry etching process is performed by an RIE (reactive ion etching) apparatus or the like, and etching is performed until the lower grad layer 112 is exposed. At this time, the photoresist forming portion is not etched, and the transparent resin layer below it remains. Next, the remaining photoresist is removed. Thus, a lattice-like core 413 as illustrated in FIG. 10B is formed.

  Next, as shown in FIG. 10C, an upper cladding layer 114 is formed so as to cover the side surface and the upper surface of the core 413. The upper cladding layer 114 is made of the same acrylic resin as the lower cladding layer 112 and is adjusted to have the same refractive index as that of the lower cladding layer 112. The upper cladding layer 114 is formed by a spin coating method or the like.

  As described above, the lower clad layer 112 and the upper clad layer 114 having different refractive indexes are formed around the core 413. As a result, the light incident on the core 413 is reflected at the boundary surface between the core 413, the lower cladding layer 112, and the upper cladding layer 114 and is confined inside the core 413. As a result, the core 413 functions as the light guide paths 31 and 431.

  At this time, the core 413 is formed in a lattice shape, and the core extending in the arrow X direction functions as the light guide path 31 and the core extending in the arrow Y direction functions as the light guide path 431.

  The light guide array 441 is formed by the above manufacturing method.

  Next, after the light guide array 441 is laminated and fixed as shown in FIG. 11, it is cut along the one-dot broken line shown in FIG. An optical device 412 as shown in FIG. 9 is formed by cutting an optical block in which a plurality of light guide path arrays 441 are stacked along a dashed line. At this time, the light guide path 31 and the light guide path 431 are cut at the intersecting portion, and the cut surface 412a becomes the detection surface S. At this time, the cut surface 412a is formed, for example, at 45 ° with respect to the end surfaces in the directions of the arrows X1 and Y1.

  An end surface 412 b in the direction of arrow Y <b> 1 of the optical device 412 serves as one end surface of the light guide path 431 and is disposed to face the light emitting unit 11. Further, the end surface 412 c of the optical device 412 in the direction of the arrow X <b> 1 is the other end surface of the light guide path 31 and is disposed to face the light receiving surface of the light receiving unit 13.

  In the manufacturing method of the optical device 412 as described above, the light guide paths 31 and 431 can be freely set in pitch, width, and the like, and can be formed with high definition. Therefore, it is possible to detect the surface shape with high definition.

[Operation]
Next, the operation of the surface shape detection apparatus 400 of this embodiment will be described.

  The processing unit 14 supplies a drive signal to the light emitting unit 11 when detecting the surface shape. The light emitting unit 11 emits light according to the drive signal from the processing unit 14. The light emitted from the light emitting unit 11 is incident on the end surface 412 b of the optical device 412. The light incident on the end surface 412b of the optical device 12 is guided through the light guide 431, reaches the cut surface 412a of the optical device 12, and enters the cut surface 412a at an angle of 45 °.

  For example, a finger 2 that is a detection target is in contact with the cut surface 412a of the optical device 12 that is the detection surface S. At this time, the convex portion of the finger 2 is in contact with the detection surface S, and the concave portion is in a separated state.

  The light that has reached the detection surface S from the light emitting unit 11 through the light guide path 431 is reflected in the extending direction of the light guide path 31 at a portion that is not in contact with the detection surface S, that is, the concave portion of the finger 2. The light reflected by the detection surface S is emitted from the emission surface 412 c of the optical device 12 through the light guide path 31.

  It should be noted that the portion that is in contact with the detection surface S, that is, the convex portion of the finger 2 is emitted from the detection surface S and is not reflected in the extending direction of the light guide path 31.

  The light emitted from the emission surface 412c of the optical device 400 is received by the light receiving unit 13 provided corresponding to the emission surface 412c.

  Therefore, on the light receiving surface of the light receiving unit 13, light is incident on a pixel portion where one end surface of the light guide 31 is opposed to the other end surface of the light guide 31 corresponding to the concave portion of the finger 2, and one end surface of the light guide 31 is Light is not incident on the pixel portion facing the other end surface of the light guide path 31 corresponding to the convex portion of the finger 2.

  Therefore, by detecting the light emitted from the end surface 412b of the optical device 412 by the light receiving unit 13, the uneven state of the finger 2 can be detected, and the fingerprint of the finger 2 can be detected.

〔effect〕
According to the present embodiment, the light emitted from the light emitting unit 11 can be supplied to the cut surface 412a, which is the detection surface S, through the light guide 431, so that the light can be consumed without waste. Further, the accuracy of reflection on the detection surface S can be improved, and accurate detection is possible.

[Others]
In the present embodiment, the intersection angle between the light guide path 31 and the light guide path 431 is 45 °. However, the intersection angle is not limited to 45 °, and may be any angle that allows good detection. It is not limited.

It is a system configuration figure of the 1st example of the present invention. It is a system configuration figure of the 1st example of the present invention. 3 is a perspective view of the optical device 12. FIG. 6 is a diagram for explaining a method of manufacturing the optical device 12. FIG. 6 is a diagram for explaining a method of manufacturing the optical device 12. FIG. 10 is a perspective view of a modification of the optical device 12. FIG. It is a system configuration | structure figure of 2nd Example of this invention. It is a system configuration | structure figure of 3rd Example of this invention. 4 is a perspective view of an optical device 412. FIG. FIG. 10 is a diagram for explaining a manufacturing method of the optical device 412. FIG. 10 is a diagram for explaining a manufacturing method of the optical device 412.

Explanation of symbols

1, 300, 400 Surface shape detection device 2 Finger 11 Light emitting unit, 12, 212, 412 Optical device, 13 Light receiving unit, 14 Processing unit 12a, 212a, 412a Cut surface, 12b, 121b Emission surface 412b, 412c End surface S Detection surface 31, 431 Light guide 41 Light guide array 111 Substrate, 112 Lower clad layer, 114 Upper clad layer 113, 413 Core

Claims (8)

In a surface shape detection apparatus having an irradiating means for irradiating light to a detection surface arranged opposite to a detection surface, and a detection means for detecting and detecting reflected light from the detection surface by a light receiving surface,
A plurality of light guide array in which a plurality of first light guides are formed, and an optical element formed by stacking,
The optical element is shaped and arranged so that one end surfaces of the plurality of first light guide paths are opposed to the detection surface, and the other end surfaces of the plurality of first light guide paths are on the light receiving surface of the detection means. A surface shape detection device characterized by being shaped and arranged to face each other. The surface shape detection device according to claim 1, wherein the optical element is formed such that one end surfaces of the plurality of first light guide paths and the other end surfaces of the first plurality of light guide paths are inclined with respect to each other. The optical element is shaped and arranged so that one end surface thereof faces the irradiation means, and the other end surface is shaped and arranged so as to face the detection surface, and is formed so as to cross the plurality of first light guide paths. The surface shape detection apparatus according to claim 1, further comprising a plurality of second light guide paths. An optical device for guiding and emitting light incident on one end surface to the other end surface,
A plurality of light guide path arrays in which a plurality of first light guide paths are formed are stacked,
One end surfaces of the plurality of first light guide paths are formed in parallel with a light incident surface, and the other end surfaces of the plurality of first light guide paths are formed in parallel with a light exit surface. An optical device. The optical apparatus according to claim 4, wherein one end face of the plurality of light guide paths and the other end face of the plurality of light guide paths are formed to be inclined with respect to each other. The light guide array has a first end surface different from the incident surface, is formed in parallel with another incident surface on which light is incident, and the other end surface coincides with one end surface of the plurality of first light guide paths. 6. The optical device according to claim 4, further comprising a plurality of second light guides that are formed in a shape intersecting with the plurality of first light guides. A light guide array forming step for forming a light guide array in which a plurality of light guides are formed in a planar shape;
A light guide block forming step for forming a light guide block formed by laminating a plurality of the light guide arrays formed in the light guide array forming procedure;
A method of manufacturing an optical device, comprising: a light guide path block cutting step of cutting the light guide path block formed by the light guide path block forming procedure obliquely with respect to an extending direction of the light guide path. The light guide path array forming step includes forming a plurality of light guide paths on a substrate,
The optical device manufacturing method according to claim 5, further comprising: a light guide path separation process for separating the light guide path from the substrate.

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