JPH11284159A - Waveguide type image sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waveguide type image sensor which is, of good SN ratio and high resolution and simple structure, easily manufactured by preventing needless light or leaked light infringing in a waveguide clad from infringing in a photoelectric transfer element array. SOLUTION: A waveguide array 4 and a photoelectric transfer element array 5 are optically coupled. Here, a bending part 9 is provided between an input and output ends of the waveguide array 4. So, a needless light 8 such as stray light infringing in a waveguide clad 7 comes out of the bending part 9 into the outside air, while the light in a waveguide core 6 reaches the photoelectric transfer element array 5. Thus, SN ratio is raised for improved resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide device which is an optical system such as a waveguide reduction image sensor used for reading an image, and more particularly to a facsimile, an optical scanner for a computer, a bar code scanner, a copying machine, and the like. The present invention relates to a waveguide type image sensor to be used.

[0002]

2. Description of the Related Art In recent years, with the increasing demand for image reading of facsimile machines, image scanners, digital copiers and the like, there has been a demand for higher performance and smaller size of one-dimensional image sensors for converting image information into electric signals. Conventionally, a one-dimensional image sensor has a sensor length that is shorter than the document width and has a reduced image sensor that uses a reduced optical system to read an image, and a close-contact imager that uses a one-to-one optical system to read an image at 1: 1 magnification. Type image sensor.

A reduced image sensor has a large depth of focus and is capable of high-speed reading. On the other hand, an optical distance is required because light is condensed by a lens and reflected by a mirror, and as a result, its size is increased. Thus, it is difficult to reduce the size. Also, the adjustment of the optical system is complicated,
There is also a drawback that requires adjustment for each unit. The contact image sensor has a short distance from the document to the photoelectric conversion element and requires no adjustment, but has a short focal depth, a low document reading speed, and the dimensions of the photoelectric conversion element require the same width as the document width. Therefore, there is a disadvantage that it is large and it is difficult to reduce the size.

Therefore, a reduction optical image sensor using an optical waveguide has been proposed. This is a waveguide type image sensor that uses a waveguide to reduce the reflected light from the original surface, and includes a microlens formed in the width of the original surface and a plurality of light guides for guiding the light condensed by the microlens. A waveguide substrate having a waveguide formed therein; and a photoelectric conversion element array for converting light guided by the plurality of waveguides into an electric signal. Therefore, miniaturization, thinning, and long focal depth can be achieved, and complicated adjustment of the optical system is not required.
-301730 gazette).

FIG. 11 is a structural view showing an example of a conventional waveguide type reduced image sensor, and FIG. 11 (a) is a perspective view.
(B) is a side view. Here, the waveguide array 4 includes a core 6 having a high refractive index n1 and a clad 7 having a low refractive index n2, which serve as light paths. Therefore, the light input to the core 6 due to the difference in the refractive indexes n1 and n2 is
The light travels while repeating total reflection at the boundary surface with, and is transmitted from the input side to the output side.

In order to efficiently guide the reflected light from the original to the waveguide and to secure a long focal depth, a microlens array 3 is provided at the waveguide array input portion. Here, the light condensed on each core 6 by each microlens is optical information from each part of the document surface, and it is necessary to separate these from each other and guide the light to the photoelectric conversion element array 5. Need to avoid crosstalk. For this reason, in FIG. 12, the numerical aperture NA of the micro lens in the micro lens array substrate 12 is shown.
1 and the numerical aperture NA of the waveguide in the waveguide array substrate 13
Design to match wg.

[0007]

(Equation 1)

When the microlens array 3 is designed in this manner, as shown in FIG. 13, the reflected light 14 from the area A of the document surface 1 forms an image on the incident surface of the waveguide and is effectively incident on the core 6. You. Further, for example, the reflected light 15 from the point B incident on the adjacent microlens enters the core 6 at an angle larger than the critical angle for being confined in the core 6. Therefore, the reflected light 15 from the point B is emitted to the outside of the core 6, and no crosstalk occurs between the cores 6. As described above, the light reflected from each area of the document surface is designed to be condensed by one microlens corresponding to each area and to be incident on one waveguide.

[0009]

However, in the above-mentioned waveguide type image sensor, unnecessary light 16a entering from a region other than the microlens and light leaking 16b from an adjacent lens as shown in FIG. 13 enters the cladding 7. And FIG. 15 (a),
(B) As shown in FIG.
Is incident on the photoelectric conversion element array 5. Here, FIG.
5A is a configuration diagram showing unnecessary light or light leakage 17 in the cladding of the waveguide array 4 entering the photoelectric conversion element array 5, and FIG. 5B is a side view. As a result, the S / N ratio is reduced, which causes deterioration in resolution. An object of the present invention is to provide a waveguide type image sensor which can prevent unnecessary light or light leakage entering a clad from entering a photoelectric conversion element array, has a high SN ratio, has a high resolution, has a simple structure, and is easy to manufacture. As an issue.

[0010]

According to the first aspect of the present invention,
In a waveguide image sensor in which a waveguide array and a photoelectric conversion element array are optically combined, a bend is provided between an input end and an output end of the waveguide array, and a light input portion of the waveguide array is provided. A waveguide-type image sensor, wherein the photoelectric conversion element array is provided outside an extension surface of a clad surface. According to the invention described in claim 1,
This means that the waveguide array between the waveguide array light input section and the waveguide array light output section has a bent portion. Therefore, most of the unnecessary light or leaked light that has entered the cladding of the waveguide array goes straight to the outside air at the bent portion, and only the light in the waveguide core reaches the photoelectric conversion element. As a result, the SN ratio increases and the resolution improves.

According to a second aspect of the present invention, in the waveguide type image sensor according to the first aspect, at least a part of a waveguide clad surface including a bent portion of the waveguide array is formed as a scattering surface. The feature is a waveguide type image sensor. According to the second aspect of the present invention, unnecessary light and light leaking into the clad efficiently escape to the outside air from the scattering surface, do not reach the photoelectric conversion element, and provide a good SN ratio. .

According to a third aspect of the present invention, in the waveguide type image sensor of the first aspect, an absorbing member for absorbing light is provided on at least a part of the waveguide clad surface including the bent portion of the waveguide array. This is a waveguide type image sensor. According to the invention described in claim 3,
Unnecessary light and leaked light that have entered the clad are absorbed by the absorbing member, and only the light in the waveguide core reaches the photoelectric conversion element, so that a high S / N ratio and high-resolution image can be obtained.

According to a fourth aspect of the present invention, in a waveguide type image sensor in which a waveguide array and a photoelectric conversion element array are optically combined, a waveguide array is provided between an input end and an output end of the waveguide array. A waveguide type image sensor, characterized in that a part of one clad surface is provided with an uneven portion located outside an extension surface of the other clad surface, and the concave portion is provided with an absorbing member for absorbing light. . According to the fourth aspect of the invention, unnecessary light and light leaking into the clad at the time of reading a document are almost straight and enter the absorbing member and are absorbed. On the other hand, since the light of the waveguide core reaches the photoelectric conversion element, a high-resolution image with a high SN ratio is obtained.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 is a configuration diagram of a waveguide type image sensor according to a first embodiment of the present invention.
(A) is a perspective view, (b) is a side view corresponding to (a),
(C), (d) is another side view.

As shown in FIGS. 1A and 1B, the waveguide type image sensor according to the present embodiment collects reflected light from the original 1 and a light emitting diode array 2 for irradiating the original 1. A micro-lens array 3 that emits light, a waveguide array 4 that guides the light condensed by the micro-lens array 3 as optical information and reduces it, and a photoelectric converter that converts the optical information from the waveguide array 4 into an electric signal. Conversion element array 5 CC
D (charge-coupled device). Further, the waveguide type image sensor according to the present embodiment is configured to remove unnecessary light or light leakage 8 that has entered the clad 7 of the waveguide array 4 when reading a document.
A bent portion 9 is formed in the waveguide array 4 between the input end and the output end of the waveguide array 4, and the photoelectric conversion element array 5 is provided outside the extension surface 11 of the clad surface of the light input portion of the waveguide array 4.

Here, the waveguide shape (core shape) has a width of 8 μm.
m, depth 8 μm, and waveguide pitch (core pitch) are 125 μm on the light input side and 14 μm on the light output side.
The refractive index of the core 6 was 1.51, the refractive index of the clad 7 was 1.49, and the refractive index of the clad flat substrate 24 (shown in FIG. 3) was 1.49. The micro lens array 3 used in the present embodiment has an effective aperture of 125 μm, a lens pitch of 125 μm, and a refractive index of 1.49. Further C
The CD has 2048 pixels and a pixel size of 14 μm ×
12 μm and the pixel pitch is 14 μm.

Next, a waveguide made of a polymer material according to the present embodiment and a method of manufacturing the same will be described. First, a method for manufacturing a clad planar substrate constituting the waveguide of the present embodiment will be described. As shown in FIG. 2A, first, a photoresist 19 is applied to the main surface of the quartz glass substrate 18, and then, as shown in FIG. The pattern of the groove for filling the material is exposed on the photoresist 19. Next, as shown in FIG. 5C, the photoresist 19 having the groove pattern exposed is subjected to an etching process to form a concave portion.

Next, as shown in FIG. 1D, a metal film 22a is formed on the main surface side of the quartz glass substrate 18 in which the concave portion is formed by using an electroplating method. Next, as shown in FIG. 3E, the support plate 23 is bonded on the metal film 22a with an epoxy-based adhesive or the like to reinforce the metal plate 22a. Separated from
A mold 22b having a plurality of rib-shaped protrusions is obtained. Next, the clad substrate 25 is formed by the 2P molding method using the mold 22b.
Prepare b. The 2P molding method is a type of duplication method using a photocurable resin, and is a method applied to the production of optical disks and the like.

First, as shown in FIG. 3A, a photo-curable resin 2 is formed on the surface of a mold 22b on which an uneven pattern is formed.
5 and a transparent flat plate (cladding flat substrate) 24 is placed thereon. Next, as shown in FIG. 3B, the photocurable resin 25 is cured. Next, as shown in FIG. 3C, the cured photocurable resin 25 is peeled off from the mold 22b to obtain a transparent resin body (cladding substrate) 25a having an uneven pattern on the surface.

Next, a method of manufacturing a waveguide by filling the core material into the groove 25b of the clad substrate will be described. First, as shown in FIG. 4A, a clad substrate 25a having a plurality of grooves 25b formed on a main surface is prepared. FIG.
As shown in (1), a core material 26 such as an ultraviolet curable resin is applied to the main surface of the clad substrate 25a. Next, FIG.
As shown in FIG. 2, the excess core material 26 existing outside the groove 25b is removed by sweeping with a squeegee material 27.
Only 5b is filled with the core material 26. Then, as shown in FIG. 4D, the core material 26 inside the groove 25b is cured by irradiating the ultraviolet rays 21 to form the core 28 of the waveguide.

Next, as shown in FIG. 2E, a clad material 29 is formed on the main surface of the clad substrate 25a on which the core 28 is formed.
Is applied, and a transparent flat plate (clad flat substrate) 24 is placed.
As shown in FIG. 3F, the cladding material 29 is cured by irradiating ultraviolet rays 21 to obtain a waveguide. Here, in the waveguide array 4 of the present embodiment, the thickness of the clad substrate 25a in which a plurality of grooves are formed is 20 μm, the thickness of the clad material 29 is 20 μm, and the thickness of the clad flat substrate 24 is 250 μm.
m, and the total waveguide thickness is about 550 μm.

Next, the waveguide array 4 is bent so as to provide the photoelectric conversion element array outside the extension surface 11 of the clad surface of the light input portion of the waveguide array 4. Here, bending the waveguide array 4 essentially causes some optical loss. However, by increasing the bending radius of curvature (ROC) as follows, this loss can be neglected.

[0023]

(Equation 2)

Here, N is the refractive index of the core 6, λ is the wavelength of the light used, a is the width of the waveguide, and n is the refractive index of the cladding 7. In the present invention, N = 1.51, λ = 570 nm, a
= 8 μm and n = 1.49, the minimum value ROC corresponds to about 85 μm. In the present invention, in order to completely eliminate the loss, the ROC was set to 10 mm and the waveguide array 4 was bent. The waveguide array 4 can be easily bent because it is in the form of a film.

When the waveguide loss before and after the bending of the waveguide was compared, there was no change and good characteristics of 0.2 dB / cm were exhibited. Next, the light intensity of the unnecessary light and the leakage light 8 at the output end of the waveguide clad before and after the bending was measured, and the stray light attenuation due to the bending was found to be 14 dB. When the original was actually read using this waveguide as an image sensor, it was possible to read with a high SN ratio and high resolution.

In the above-described embodiment, FIG.
As shown in (b), the area of the bent portion 9 is changed to the waveguide thickness 10
However, if the photoelectric conversion element array 5 is located outside the extension surface 11 of the clad surface of the light input portion of the waveguide array 4, as shown in FIG. It may be smaller than 10. Further, as shown in FIG. 3D, two bent portions 9 may be provided. The angle β between the waveguide input end face and the photoelectric conversion element face may be any number.

<Second Embodiment> FIG. 5A is a side view of a waveguide image sensor according to a second embodiment of the present invention. This waveguide type image sensor has substantially the same configuration as that shown in FIG. The difference from the waveguide type image sensor of FIG. 1 is that at least a part of the surface of the waveguide clad 7 including the bent portion 9 is processed into the scattering surface 30. In this embodiment, the surface of the waveguide clad 7 is processed into a scattering surface using sandpaper. However, a clad substrate 25a having a scattering surface can be easily manufactured by injection molding technology or the like.

Using the waveguide array of the second embodiment,
Unwanted light and light leakage in the cladding 7 were measured and compared with those of the conventional waveguide array. As a result, the amount of stray light attenuation was 17 dB. When the original was actually read using the waveguide array of the second embodiment as an image sensor, it was possible to perform high-resolution reading with a high SN ratio.

Here, for example, as shown in FIG. 5 (b), when the region of the bent portion 9 is smaller than the waveguide thickness 10, at least the bent portion 9 and the region of the waveguide thickness 10 or more should be the scattering surface 30. Is desirable. In the above-described embodiment,
Although a part of the surface of the waveguide clad 7 including the bent portion is a scattering surface, the entire surface of the waveguide clad 7 may be a scattering surface 30 as shown in FIG.

<Third Embodiment> FIG. 6A is a side view of a waveguide type image sensor according to a third embodiment of the present invention. This waveguide type image sensor is shown in FIGS.
The configuration is almost the same as that shown in FIG. The difference from the waveguide type image sensor of FIGS. 1 and 5 is that an absorbing member 31 is provided on a part of the surface of the waveguide clad 7 including at least the bent portion 9 of the waveguide array. The absorbing member 31 used in the third embodiment is an acrylic resin black paint.

Next, in order to confirm the effect, the light intensity of unnecessary light and light leakage was measured and compared with the case of a conventional waveguide array. As a result, the stray light attenuation was found to be 19 dB. When the original was actually read using this waveguide as an image sensor, it was possible to read with a high SN ratio and high resolution. For example, FIG.
As shown in (b), when the region of the bent portion 9 is smaller than the waveguide thickness 10, at least the bent portion 9 and the waveguide thickness 10
It is desirable to cover an area or more with the absorbing member 31.

Further, in order to absorb unnecessary light and leaked light and to block unnecessary light from the outside entering from the surface of the waveguide clad 7, the light is absorbed over the entire surface of the waveguide clad 7 as shown in FIG. A member 31 may be provided.
In the above-described embodiment, the acrylic resin black paint is used as the absorbing member, but any material that absorbs light may be used, for example, black polycarbonate, black polyester film, oil-based black ink, or the like. Good.

<Fourth Embodiment> FIGS. 7A and 7B are configuration diagrams of a waveguide type image sensor according to a fourth embodiment of the present invention, wherein FIG. 7A is a perspective view, and FIG. (A) is a side view, and (c) to (e) are other side views. As shown in FIGS. 7A and 7B, the waveguide type image sensor according to the present embodiment includes a light emitting diode array 2 that irradiates a document surface of a document 1 and a micro-beam that collects reflected light from the document 1. A lens array 3, a waveguide array 4 for guiding light condensed by the microlens array 3 as optical information and reducing it, and a photoelectric conversion element array for converting the optical information from the waveguide array 4 into an electric signal 5 CCDs (Charge Coupled Devices). Further, the waveguide type image sensor according to the present embodiment has an input end and an output end of the waveguide array 4 for removing unnecessary light and light leaking into the clad 7 of the waveguide array 4 when reading a document. The part 9c of one clad surface of the waveguide array 4 is formed on the extended surface 1 of the other clad surface.
A concave / convex portion 41 located outside the concave portion 1 is provided, and an absorbing member 40 for absorbing light is provided on the surface of the concave portion.

Here, the waveguide shape (core shape) has a width of 8 μm.
m, depth 8 μm, and waveguide pitch (core pitch) are 125 μm on the light input side and 14 μm on the light output side.
The refractive index of the core 6 was 1.51, the refractive index of the clad 7 was 1.49, and the refractive index of the clad flat substrate was 1.49. The microlens array 3 used in the present embodiment has an effective aperture of 125 μm and a lens pitch of 125 μm.
m, the refractive index is 1,49. Further, the CCD has 2048 pixels, a pixel size of 14 μm × 12 μm, and a pixel pitch of 14 μm.

Next, a waveguide made of a polymer material according to the embodiment of the present invention and a method of manufacturing the same will be described.
The method of manufacturing the waveguide by filling the core material into the clad substrate 25a and the groove 26b of the clad substrate 25a constituting the waveguide of the present embodiment is the same as in the first to third embodiments. It will not be described in detail.

Next, a method of manufacturing the waveguide array 4 having desired irregularities according to the present embodiment will be described. FIG. 8 (a)
A waveguide array is prepared as shown in FIG. An absorbing member 40 for absorbing light is already provided on a clad surface portion which becomes a concave portion at a desired position. Next, as shown in FIG. 8B, three cylindrical bodies 44 and 44a made of a polymer having a desired radius of curvature are arranged in the waveguide array (FIG. 8 shows a part of the cylindrical body). In the present embodiment, the curvature radius is 10 mm
Was used. Then, the curved surface portions of the cylindrical bodies 44 and 44a are brought into close contact with the clad surface of the waveguide array.
Then, as shown in FIG. 4C, the cylindrical body 44a located at the center is pushed so that a part 9c of one clad surface of the waveguide array is located outside the extension surface 11 of the other clad surface. Go out. As a result, as shown in FIG. 4D, the irregularities 41 are formed on the waveguide array along the curved surfaces of the cylindrical bodies 44 and 44a. As a result, the irregularities 41 having a desired radius of curvature are formed on the waveguide array. Can be made. Since the waveguide array has a film shape, it can be easily bent, that is, the irregularities 41 can be formed.

When the insertion loss before and after bending of the waveguide array was compared, there was no change and the insertion loss was 3.0 dB. Next, in order to confirm the effect of reducing the stray light of the waveguide array of the present embodiment, the dependency between the cladding surface position of the apex of the concave portion of the waveguide array uneven portion and the amount of stray light attenuation was measured. As shown in FIG. 9A, the cladding surface 9 on the lower surface before bending.
Assuming that the position t of a is zero and the waveguide array is bent (unevenness) as shown in FIG. 2B, t is gradually increased. The amount of stray light in the clad 7 at that time is measured at the waveguide clad output section. Note that the thickness of the waveguide array is T = 550 μm, and as shown in FIG.
When = T, it indicates that the position of the extension surface 11 of the upper clad surface is equal to the position of the clad surface 9b of the concave top of the lower surface.

FIG. 9D shows the result. The vertical axis represents the stray light attenuation (dB) of the waveguide array according to the present embodiment with respect to the stray light amount of the conventional waveguide array, and the horizontal axis represents the position t of the cladding surface at the top of the concave portion that can be the concave and convex portion of the waveguide array. t
At <T, the gradient of the characteristic of the amount of stray light attenuation is steep, and when t> T at t = T, the amount of stray light attenuation gradually converges to about 20
It converged to dB. When the original was actually read using the waveguide array in the case of t <T as an image sensor, the reading was low in SN ratio and very poor in resolution.

When an original is actually read using the waveguide array at t> T as an image sensor, SN
High-resolution, high-resolution reading could be performed.

This is presumably because, as shown in FIG. 10, unnecessary light or leaked light 17c entering the clad 7 from the microlens array 3 travels straight at the bent portion 41 and is absorbed by the absorbing member 40. As a result, unevenness is provided so that a part of one clad surface of the waveguide array is located outside the extension surface 11 of the other clad surface, and an absorbing member for absorbing light is provided on the clad surface of the concave portion. It turns out that it is good.

In the above-described embodiment, a black paint made of acrylic resin is used as the absorbing member. However, if it absorbs light, for example, a black polycarbonate, a black polyester film or the like is provided on the cladding surface. May be.
Further, in the present embodiment, the absorbing member for absorbing light is provided on the surface of the concave clad, but in order to further absorb unnecessary light and leaked light, and to block unnecessary light from the outside entering from the surface of the waveguide clad 7. Alternatively, an absorbing member 40 may be provided on the entire surface of the waveguide clad 7 as shown in FIG.

The above four embodiments are described. In these embodiments, a clad substrate 25a on which a waveguide pattern is formed by a 2P molding method is manufactured, and a film-shaped waveguide is formed using the clad substrate 25a. Although an array is manufactured, the present invention is not limited to this manufacturing method and a film-shaped waveguide array. For example, the clad substrate 25a may be manufactured by injection molding or the like. In a waveguide array having a thick waveguide layer, for example, FIG.
As shown in (d), a fine groove 42 is formed in the clad surface portion to be bent to facilitate bending, or, for example, as shown in FIG. As described above, the waveguide clad can be easily bent by processing it thinly.

Further, a 2P molding method or an injection molding method using a mold having a bent portion in advance may be used, and any other material or manufacturing method may be used. In this specification, providing the photoelectric conversion element array outside the extension surface of the clad surface of the light input portion of the waveguide array means that even the entire case of the photoelectric conversion element array is provided outside the extension surface. , But at least the light receiving portion of the photoelectric conversion element array is provided outside the extension surface. However, in order to prevent unnecessary light and leak light from being received by the photoelectric conversion element array, it is desirable to provide the photoelectric conversion element array outside the extension surface including the case of the photoelectric conversion element array.

[0044]

According to the first aspect of the present invention, in a waveguide type image sensor in which a waveguide array and a photoelectric conversion element array are optically combined, a portion between an input terminal and an output terminal of the waveguide array is provided. And the photoelectric conversion element array is provided outside the extended surface of the clad surface of the light input portion of the waveguide array, so that unnecessary light and light leaking into the clad of the waveguide array are transmitted to the bent portion. Out of the air, and the light in the waveguide core reaches the photoelectric conversion element. Therefore, the SN ratio is increased, and the resolution is improved. Further, the structure is simple and the fabrication is easy.

According to the second aspect of the present invention, in the waveguide type image sensor according to the first aspect, at least a part of the waveguide clad surface including the bent portion of the waveguide array is formed as a scattering surface. Unnecessary light or leaked light that enters enters the outside air at the scattering surface, and does not reach the photoelectric conversion element. Therefore, the SN ratio increases,
Resolution is improved. Further, the structure is simple and the fabrication is easy.

According to the third aspect of the present invention, in the waveguide type image sensor according to the first aspect, at least a part of the waveguide clad surface including the bent portion of the waveguide array absorbs light. Therefore, most of the unnecessary light and light leaking into the clad go straight, enter the absorbing member, and are absorbed. As a result, the SN ratio increases, and the resolution improves. Further, the structure is simple and the fabrication is easy.

According to the fourth aspect of the present invention, in a waveguide type image sensor in which a waveguide array and a photoelectric conversion element array are optically combined, a waveguide is provided between an input terminal and an output terminal of the waveguide array. A part of one clad surface of the waveguide array was provided with an uneven portion located outside the extension surface of the other clad surface, and the concave portion was provided with an absorbing member for absorbing light, so that it entered the clad of the waveguide array. Most of unnecessary light and leaked light go straight and enter the absorbing member, and are absorbed. On the other hand, since the optical signal in the waveguide core reaches the photoelectric conversion element, an image with a high SN ratio and high resolution can be obtained.

[Brief description of the drawings]

FIG. 1A is a schematic perspective view showing a configuration of a waveguide type image sensor according to a first embodiment of the present invention, and FIG. 1B is a side view. (C) is a side view showing the configuration when the bent portion is smaller than the thickness of the waveguide. (D) is a side view showing a configuration in the case of having two bent portions.

FIG. 2 is a diagram illustrating a method for manufacturing a mold for a clad substrate according to the first embodiment.

FIG. 3 is a diagram illustrating a method for manufacturing the clad substrate according to the first embodiment.

FIG. 4 is a diagram for explaining a method of manufacturing a waveguide by filling a clad substrate of the first embodiment with a core material.

FIG. 5 is a side view illustrating a configuration of a waveguide image sensor according to a second embodiment of the present invention.

FIG. 6 is a side view illustrating a configuration of a waveguide image sensor according to a third embodiment of the present invention.

FIG. 7A is a schematic perspective view showing a configuration of a waveguide type image sensor according to a fourth embodiment of the present invention, and FIG. 7B is a side view. (C) is a side view showing a configuration of a waveguide type image sensor in which an absorbing member is provided on the entire surface of the clad.
(D) is a side view showing the configuration of the waveguide type image sensor in which fine grooves are provided on the surface of the waveguide clad that is to be bent. (E) is a side view showing a configuration of a waveguide type image sensor in which a waveguide clad serving as a bent portion is processed to be thin.

FIG. 8 is an explanatory diagram illustrating a method for manufacturing a waveguide uneven portion according to a fourth embodiment.

FIG. 9A is a side view showing a state before the waveguide is bent (the lower clad surface t = 0). (B)
FIG. 4 is a side view showing a waveguide having a bend and showing a clad surface position t = T / 2 at the top of a concave portion. (C) is a side view of the waveguide showing a case where the cladding surface position t at the top of the concave portion is equal to the waveguide thickness T. (D) is a diagram showing the relationship between the position t of the height of the cladding surface at the top of the concave portion of the waveguide array uneven portion and the amount of stray light attenuation.

FIG. 10 is a side view showing an optical path in which unnecessary light and leaked light in a waveguide clad are absorbed by an absorbing member.

11A is a schematic perspective view showing a configuration of a conventional waveguide image sensor, and FIG. 11B is a side view.

FIG. 12 is a principle diagram of a numerical aperture of a microlens and a waveguide.

FIG. 13 is a diagram showing an optical path of stray light accompanying a micro lens.

FIG. 14 is a diagram illustrating optical paths of unnecessary light and light leakage.

FIG. 15 is a diagram illustrating optical paths of unnecessary light and light leaking into a photoelectric conversion element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Original 2 Light emitting diode array 3 Micro lens array 4 Waveguide array 5 Photoelectric conversion element array 6 Core 7 Cladding 8 Unnecessary light and light leakage 9 Bending part 10 Waveguide thickness 11 Extension surface of cladding surface 12 Microlens array substrate 13 Waveguide array Substrate 14 Reflected light from document 15 Reflected light from document by adjacent microlens 16a Unwanted light, 16b Leakage light 17 Unwanted light and light leakage 18 Quartz glass substrate 19 Photoresist 20 Photomask 21 Ultraviolet 22a Metal film, 22b Mold 23 Support plate 24 clad flat substrate 25 photo-curable resin, 25a clad substrate, 25
b groove 26 core material (ultraviolet curable resin) 27 squeegee material 28 core 29 clad material 30 scattering surface 31, 40 absorbing member 41 uneven part (bent part)

Claims (4)

[Claims] 1. A waveguide type image sensor in which a waveguide array and a photoelectric conversion element array are optically combined, wherein the waveguide array has a bend between an input end and an output end thereof, and A waveguide type image sensor, wherein the photoelectric conversion element array is provided outside the extension surface of the clad surface of the light input section. 2. A waveguide type image sensor according to claim 1, wherein at least a part of a waveguide clad surface including a bent portion of said waveguide array is a scattering surface. Image sensor. 3. The waveguide type image sensor according to claim 1, wherein an absorbing member for absorbing light is provided on at least a part of a waveguide clad surface including a bent portion of the waveguide array. Waveguide type image sensor. 4. In a waveguide type image sensor in which a waveguide array and a photoelectric conversion element array are optically combined, one clad surface of the waveguide array is provided between an input end and an output end of the waveguide array. A waveguide type image sensor, comprising: an uneven portion partially provided outside the extension surface of the other clad surface; and an absorbing member for absorbing light in the concave portion.