KR20120060187A - Optical waveguide with light-emitting element and optical touch panel with the same - Google Patents

Abstract

PURPOSE: An optical waveguide with a light emitting device and an optical touch panel including the same are provided to emit light with uniform intensity and a narrow width from each branch. CONSTITUTION: An optical waveguide(12) includes a light emitting device(11) and a core(13). The core induces light from the light emitting device and generates a plurality of beams. The core includes a main line(14) and a plurality of branch lines(15). The plurality of the branch lines are branched from the main line at a plurality of branch points(16). The main line includes a side(14a) with a branch point and a side(14b) without the branch point. The plurality of branch points are formed in a straight line.

Description

Optical waveguide with a light emitting element, and an optical touch panel having the same {OPTICAL WAVEGUIDE WITH LIGHT-EMITTING ELEMENT AND OPTICAL TOUCH PANEL WITH THE SAME}

The present invention relates to an optical waveguide in which a light emitting element having a novel branching structure for generating a plurality of light rays from one light emitting element is formed. Moreover, it is related with the optical touch panel provided with the optical waveguide in which the light emitting element was formed.

Conventionally, the optical waveguide in which the light emitting element was formed which has a branched structure for generating a plurality of light rays from one light emitting element is known (for example, patent document 1). An optical waveguide in which a light emitting element of this kind is formed is preferably used for emitting light rays to a coordinate input region of an optical touch panel.

8 is an optical waveguide 40 in which a light emitting element having a conventional branching structure is formed. In the optical waveguide 40 in which the conventional light emitting element is formed, the plurality of branch points 42 are mainly formed of the core 43 in order to distribute the light from the light emitting element 41 to the respective branch paths 46. It is formed in the direction orthogonal to the light guide direction 45 of 44.

The optical waveguide 40 in which the light emitting element having such a structure is formed has a problem that the width W2 of the 44 is mainly widened because the gap 47 is required between the adjacent branch paths 46 (gap). 47 is filled with a cladding layer). Moreover, since the difference in the length of each branch path 46 is large, a difference tends to occur in the light transmission efficiency between each branch path 46, and the intensity of the light emitted from each branch path 46 tends to be uneven. There was also.

United States Patent Publication No. 2006/0188198

The optical waveguide 40 in which the light emitting element having a conventional branching structure is formed is mainly formed in a direction orthogonal to the light guiding direction 45 of the plurality of branching points 42, and thus mainly the width of the 44. (W2) There is a problem that this is wide. Moreover, since the difference of the length of each branch path 46 is large, there exists a subject that the intensity of the light radiate | emitted from each branch path 46 tends to become nonuniform.

An object of the present invention is to realize an optical waveguide in which a light emitting element is formed, the width of which is mainly smaller than that of the related art, and the intensity of light emitted from each branch path is uniform.

The gist of the present invention is as follows.

) 는 0.1 °? 2.0 °이다. 주로의 분기점을 갖지 않는 변과, 주로의 도광 방향이 이루는 각도 (θ) 는 0.3 °? 1.7 °이다. (1) An optical waveguide in which the light emitting element of the present invention is formed is an optical waveguide in which a light emitting element having a light emitting element and an optical waveguide including a core for guiding light from the light emitting element to generate a plurality of light rays. The core has a main branch and a plurality of branch paths branched from the main branch at a plurality of branching points. Mainly, the side which has a branch point, and the side which does not have a branch point are provided. The sides with branch points and the sides without branch points face each other. The plurality of branch points on the side having the branch points are formed on a straight line substantially parallel to the mainly light guiding direction. Mainly, the width becomes narrower as it moves away from the light emitting element. In the branch point where the branch path diverges from the main road, the angle formed by the main and the light guide directions of the main road (

) Is 0.1 °? 2.0 °. The angle θ formed between the edge not having the main branch point and the main light guiding direction is 0.3 °? 1.7 °.

(2) The optical touch panel of this invention is equipped with the optical waveguide in which the light emitting element as described above was formed.

In the optical waveguide in which the light emitting element is formed of the present invention, the maximum width of the main portion of the core of the optical waveguide in which the light emitting element is formed can be made, for example, 40% or more narrower than the maximum width of the main portion of the optical waveguide in which the conventional light emitting element is formed. .

In the optical waveguide in which the light emitting element of the present invention is formed, it is possible to make it possible to uniformly distribute the light to each branch path and to narrow the maximum width of the main body.

The optical touch panel of this invention can narrow a frame part by using the optical waveguide in which the light emitting element of this invention was formed. In addition, the variation in sensitivity of the coordinate input area according to the place can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing of the optical waveguide in which the light emitting element of this invention was formed.
2 is an explanatory diagram of a core used in the present invention.
3 is an explanatory diagram showing propagation of light in an optical waveguide;
4 is an explanatory diagram of an optical touch panel of the present invention.
5 is an explanatory diagram of an optical waveguide in which a light receiving element is formed;
6 is a configuration diagram for measuring the light intensity of the optical waveguide in which the light emitting element of the present invention is formed.
7 is a light intensity distribution graph of Example 1 of an optical waveguide in which the light emitting device of the present invention is formed.
8 is an explanatory diagram of an optical waveguide in which a conventional light emitting element is formed;

[Optical Waveguide with Light Emitting Element]

As shown in FIG. 1, the optical waveguide 10 in which the light emitting element of the present invention is formed has a light emitting element 11 and an optical waveguide 12. The optical waveguide 12 includes a core 13 for guiding light from the light emitting element 11.

2 is an explanatory diagram of the core 13. As shown in FIG. 2, the core 13 mainly includes a 14 and a plurality of branch passages 15. Each branch path 15 branches mainly from 14 at each branch point 16. Mainly 14 has two sides 14a and 14b. One side 14a has the branching point 16, but the other side 14b does not have the branching point 16. FIG. The branch point 16 is mainly formed on a straight line substantially parallel to the light guiding direction 17 of the 14. The main width W is narrowed away from the light emitting element 11.

Since the optical waveguide 10 in which the light emitting element of the present invention is formed does not need to have a gap as usual between the adjacent branch paths 15, the maximum width W1 of the 14 can be narrowed mainly. . Moreover, since the difference in the length of each branch path 15 is small, the difference does not arise in the optical transmission efficiency between each branch path 15 well. Therefore, the intensity of the light emitted from each branch path 15 can be made uniform.

As shown in FIG. 3, the light 19 emitted from the light emitting element 11 propagates while fully reflecting the inside of the core 13 embedded in the optical waveguide 12, and passes through each branch path 15. Emitted from the tip of the.

) 를 이룬다. 각도 (

) 는, 바람직하게는 0.1 °? 2.0 °이고, 보다 바람직하게는 0.1 °? 1.8 °이며, 더욱 바람직하게는 0.1 °? 1.6 °이다. As shown in FIG. 1, 2, the main part 14 of the optical waveguide 10 in which the light emitting element of this invention was formed has two sides 14a and 14b, and one side 14a has the branching point 16. As shown in FIG. , But the other side 14b does not have a branching point 16. The position of each branch point 16 is mainly in the straight line substantially parallel to the light guide direction 17 of 14. At the branch point 16 where each branch path 15 branches mainly from 14, the light guide direction 17 of mainly 14 and mainly 14 is an angle (

). Angle (

) Is preferably 0.1 °? 2.0 °, more preferably 0.1 °? 1.8 °, more preferably 0.1 °? 1.6 °.

) 와 각도 (θ) 의 차는, 바람직하게는 0.5 °이하이다. The side 14b which does not have the branching point 16 and the light guide direction 17 of the main part 14 mainly form the angle (theta). Angle (theta) becomes like this. Preferably it is 0.3 degrees? 1.7 °, more preferably 0.3 °? 1.5 °, more preferably 0.4 °? 1.0 °. Angle above (

) And the angle θ are preferably 0.5 ° or less.

) 와 각도 (θ) 가 상기의 범위를 하회하면, 각 분기로 (15) 로부터 출사되는 광 강도의 편차가 커진다. 반대로 각도 (

) 와 각도 (θ) 가 상기 범위를 상회하면, 주로 (14) 의 최대 폭 (W1) 이 넓어져, 종래의 발광 소자가 형성된 광 도파로 (40) 의 최대 폭 (W2) 에 가까워진다. Angle (

) And angle (theta) are less than the said range, the deviation of the light intensity emitted from each branch path 15 will become large. Reverse angle (

) And angle (theta) exceed the said range, the maximum width W1 of 14 mainly spreads and becomes close to the maximum width W2 of the optical waveguide 40 in which the conventional light emitting element was formed.

) 와 각도 (θ) 가 상기 범위에 있으면, 각 분기로 (15) 에 광을 균일하게 분배하는 것과, 주로 (14) 의 최대 폭 (W1) 을 좁게 하는 것을 양립시킬 수 있다. Angle (

) And angle (theta) are in the said range, it can make it compatible to distribute light uniformly to each branch path 15, and to narrow the largest width W1 of 14 mainly.

[Optical Touch Panel]

As shown in FIG. 4, the optical waveguide 10 in which the light emitting element of the present invention is formed is used as the light emitting side optical waveguide 21 and the light emitting element 22 of the optical touch panel 20 of the present invention.

The optical touch panel 20 of the present invention includes the coordinate input region 23, the light emitting side optical waveguide 21, the light emitting element 22, the light receiving side optical waveguide 24, and the light receiving element 25. Equipped. The light emitting side optical waveguide 21 generates a light beam 26 that traverses the coordinate input region 23 in the longitudinal direction and the transverse direction. The light-receiving side optical waveguide 24 receives the light beam 26 that has traversed the coordinate input region 23. The light receiving element 25 detects the light beams 26 received by the light receiving side optical waveguide 24.

Since the optical touch panel 20 blocks a part of the light rays 26 passing through the coordinate input area 23 with a finger, a pen, or the like, the intensity of a part of light entering the light receiving element 25 is lowered. Coordinates such as a pen can be recognized.

In the case where the conventional optical waveguide 40 is used as the light emitting side optical waveguide, for example, in order to obtain a resolution of about 3 mm in an optical touch panel having a diagonal of 12.1 inches, the width W2 of the main portion 44 of the core 43 is large. ) Is the sum of the gaps 47 between the approximately 170 branch passages 46 and each branch passage 46.

On the other hand, when the optical waveguide 10 in which the light emitting element of the present invention is formed is used for the same diagonal 12.1 inch optical touch panel, the gaps between the respective branch paths 15 are not necessary, so that the main portion 14 of the core 13 The width W1 can be as narrow as 40% or more as compared with the width W2 of the main 44 when the conventional optical waveguide 40 is used.

[Light emitting element]

The light emitting element 11 used for the optical waveguide 10 in which the light emitting element of the present invention is formed may be any as long as it generates a light ray 26 passing through the optical waveguide 12 and crossing the coordinate input region 23. Can be used.

The light emitting element 11 is preferably a light emitting diode or a semiconductor laser, and more preferably a VCSEL (vertical resonator surface emitting laser). The VCSEL resonates the light in the vertical direction of the substrate, and emits light in the vertical direction of the substrate, so the light transmission is excellent.

The wavelength of the light emitted from the light emitting element 11 is preferably any of the near infrared region (700 nm to 2500 nm).

[Optical waveguide]

In the optical waveguide 12 used for the optical waveguide 10 in which the light emitting element of the present invention is formed, a core 13 for guiding light from the light emitting element 11 to generate a plurality of light rays is embedded. The edge part 14c of the main 14 side of the core 13 is optically couple | bonded with the light emitting element 11 normally (it is called light coupling).

Although the light coupling method is not specifically limited, For example, the method of adjusting so that the center position of the light intensity distribution of the light emitting element 11 and the center of the core 13 may correspond, or the method using an optical path changing mirror. There is this. As the optical path changing mirror, for example, a V-shaped groove formed by dicing is used.

The core 13 mainly has a 14 and a plurality of branch passages 15. Each branch path 15 branches mainly from 14 at each branch point 16. Mainly 14 has two sides 14a and 14b, and one side 14a has a plurality of branching points 16, while the other side 14b does not have branching point 16.

In this specification, the "branch point 16" means the part which the side wall of the adjacent branch path 15 joins. In addition, as shown in FIG. 3, the "light-guiding direction 17" means the advancing direction of the light 19 which propagates in the core 13, and strictly, as shown in FIG. 1, the core 13 The advancing direction of the light in the main 14 just before the branch path 15 is branched.

Although the maximum width W1 of the main 14 of the core 13 differs also according to the magnitude | size of an optical touch panel, it is 500 micrometers? 10,000 μm. Mainly, the height (thickness) of (14) becomes like this. 100 μm.

As shown to FIG. 1, 2, the position of each branching point 16 lies on one straight line. The straight line is mainly substantially parallel to the light guiding direction 17 of 14. "Almost parallel" means that the deviation from the true parallel of the light guide direction 17 mainly with the straight line in which each branch point 16 was set, and is less than 0.1 degrees.

The width W of the main body 14 narrows as it moves away from the light emitting element 11 mainly along the light guide direction 17 of the main body 14. The reduction rate of the width W of the main 14 is mainly determined by the side 14b not having the branch point 16 and the angle θ formed mainly by the light guide direction 17 of the 14.

When the angle θ formed between the side 14b not having the branch point 16 of the main portion 14 and the light guiding direction 17 of the main portion 14 is less than 0.3 °, the light emitted from each branch path 15 It is difficult to make the strength uniform.

Moreover, when the angle (theta) exceeds 1.7 degrees, the largest width W1 of the main body 14 mainly becomes wide, and the width | variety (circle 44) of the main wave 44 of the optical waveguide 40 in which the light emitting element which has a conventional branched structure was formed ( Since it approaches W2), the effect of this invention cannot fully be acquired.

0.3 degrees of the angle (theta) which the side 14b which does not have the branching point 16 of 14 mainly, and the light guide direction 17 of 14 is mainly made? By setting it as 1.7 degrees, making it possible to make uniform the intensity | strength of the light beam radiate | emitted from each branch path 15, and to make narrow the largest width W1 of 14 mainly.

The number of branch paths 15 branched from one main body 14 also varies depending on the size of the optical touch panel, but preferably 40? 500 pcs. The interval between adjacent branching points 16 in the light guiding direction 17 is preferably 100 µm? 2,000 μm.

Although the cross-sectional shape of the core 13 (mainly 14 and branch path 15) is not specifically limited, Trapezoid or rectangle excellent in patterning property is preferable. The optical waveguide 12 of this configuration is excellent in propagation characteristics of light rays.

The core 13 is usually embedded in the cladding layer 18 and is formed of a material having a higher refractive index than the cladding layer 18. The material for forming the core 13 is preferably an ultraviolet curable resin excellent in patterning property.

Examples of the ultraviolet curable resins include acrylic ultraviolet curable resins, epoxy ultraviolet curable resins, siloxane ultraviolet curable resins, norbornene ultraviolet curable resins, and polyimide ultraviolet curable resins.

The cladding layer 18 is normally formed of the material whose refractive index is lower than the core 13. The material of the cladding layer 18 is not particularly limited, such as glass, silicon, metal, resin, or the like. The cladding layer 18 may be a single layer or a multilayer. When the cladding layer 18 is two layers, it is formed with an under cladding layer and an over cladding layer. The thickness t of the cladding layer 18 is preferably 5 µm to? 20 μm.

The maximum refractive index difference between the core 13 and the cladding layer 18 is preferably 0.01 or more, more preferably 0.02? 0.2. The refractive index of the resin forming the core 13 and the cladding layer 18 can be appropriately increased or decreased depending on the type and content of the organic group introduced into the resin.

For example, the refractive index of resin can be increased by introducing a cyclic aromatic group (phenyl group etc.) into a resin molecule or increasing content in the resin molecule of a cyclic aromatic group.

On the other hand, for example, the refractive index of the resin is reduced by introducing a linear or cyclic aliphatic group (methyl group, norbornene group, etc.) into the resin molecule or by increasing the content of the linear or cyclic aliphatic group in the resin molecule. You can.

The structure of the optical waveguide 12 can be produced by any method such as a dry etching method using a plasma, a transfer method, an exposure developing method, a photo bleaching method, or the like.

[Coordinate Input Area]

In this invention, the coordinate input area | region 23 means the area | region which the light beam 26 produced | generated from the light emission side optical waveguide 21 traverses. The optical touch panel 20 of the present invention performs coordinate input by blocking the light beam 26 traversing the coordinate input area 23 with a finger or a pen.

The coordinate input area 23 is typically a display screen of a liquid crystal display or a plasma display. Space may be sufficient as the front surface of the coordinate input area | region 23, and a glass plate or an acryl plate may be provided in the surface. In this case, glass plates or acrylic plates are used to increase the scratch resistance. The surface of the glass plate or the acrylic plate may be subjected to AR (anti reflection) treatment or AG (anti glare) treatment.

[Receiving Side Optical Waveguide]

The light-receiving side optical waveguide 24 used for the optical touch panel 20 in FIG. 4 is not particularly limited as long as the light-receiving side optical waveguide 24 can receive the light beams 26 that traverse the coordinate input region 23. As shown in FIG. 5, the light receiving side optical waveguide 32 preferably has a plurality of cores 31 and a cladding layer 34 to embed the cores 31. In the light receiving side optical waveguide 32, one end of the core 31 is disposed toward the coordinate input region 23. The other end of the core 31 is optically coupled (light coupled) with the light receiving element 33. The optical waveguide 30 in which the light receiving element is formed includes the light receiving side optical waveguide 32 and the light receiving element 33.

The resolution of the optical touch panel 20 using the optical waveguide is determined in principle according to the number of cores 31 of the light receiving side optical waveguide 32 optically coupled to the light receiving element 33. For this reason, a plurality of cores 31 are required. However, since the light emitting side optical waveguide 12 can emit a light ray 26 parallel to the coordinate input region 23, the main portion 14 of the core 13 that is optically coupled to the light emitting element 11 is 1, 2 may be sufficient.

[Receiving element]

The light receiving element 33 used in the present invention has a function of converting an optical signal into an electrical signal, and detects the light 26 received from the light receiving side optical waveguide 32. The light 26 detected by the light receiving element 33 is preferably light in the near infrared region (700 nm to 2500 nm).

The structure of the light receiving element 33 is preferably a one-dimensional image sensor in which light receiving units (for example, photodiodes) are arranged in a horizontal line. As such a light receiving element 33, a CMOS image sensor and a CCD image sensor are mentioned.

Example

Example 1

<Preparation of varnish for cladding layer formation>

(Component A) Epoxy-type ultraviolet curing resin (EP4080E by Adeca Co., Ltd.) which has alicyclic skeleton ... 100 parts by weight

(Component B) Photoacid Generator (CPI-200K manufactured by San Apro Company). 2 parts by weight

The above components were mixed to prepare a varnish for forming a clad layer.

<Preparation of Varnish for Core Formation>

(Component C) Epoxy-type ultraviolet curing resin (Ogsol EG by Osaka Gas Chemical Co., Ltd.) containing a fluorene skeleton. 40 parts by weight

(Component D) Epoxy-type ultraviolet curing resin (EX-1040 by Nagase Chemtex Co., Ltd.) containing a fluorene skeleton. 30 parts by weight

(Component E) 1,3,3-tris (4- (2- (3-oxetanyl)) butoxyphenyl) butane 30 parts by weight (synthesis according to Example 2 of Japanese Patent Application Laid-Open No. 2007-070320)

Component B... 1 part by weight

Ethyl lactate 41 parts by weight

The above components were mixed to prepare a varnish for core formation.

<Production of Optical Waveguide with Light-Emitting Element>

The varnish for cladding layer formation was apply | coated to the surface of the polyethylene naphthalate film of 188 micrometers in thickness, ultraviolet-ray was irradiated for 1,000 mJ / cm <2>, and it heat-processed at 80 degreeC for 5 minutes, and the under cladding layer of thickness 20micrometer was obtained. The refractive index of the under cladding layer at a wavelength of 830 nm was 1.510.

The varnish for core formation was apply | coated to the surface of an under clad layer, and it dried at 100 degreeC for 5 minutes, and formed the core layer. Next, the photomask in which the predetermined pattern was printed was put on the core layer (gap 100 µm), 2,500 mJ / cm 2 irradiated with ultraviolet rays, and further heated at 100 ° C for 10 minutes.

Next, the ultraviolet-ray unirradiated part of the core layer was melt | dissolved and removed by (gamma) -butyrolactone aqueous solution, and it heat-processed at 120 degreeC for 5 minutes, and the pattern of the core was formed. The patterned core consists mainly of (maximum width 3,239 μm, height 50 μm) and 274 branches (15 μm in width, 50 μm in height) which are sequentially branched along the main light guiding direction. The refractive index of the core at a wavelength of 830 nm was 1.592.

As shown in FIG. 1, the core 13 contained in the optical waveguide 10 in which this light emitting element was formed has mainly 14 and the some branch path 15 branched mainly from the 14. Mainly, 14 has two sides 14a and 14b, one side 14a has a branching point 16, and the other side 14b does not have a branching point 16.

As shown in FIG. 1, the position of each branch point 16 lies on one straight line, and the straight line is substantially parallel to the light guiding direction 17 of the 14. The width | variety (W) becomes narrower as the main body 14 moves away from the light emitting element 11 along the light guide direction 17 of the main body 14 mainly.

) 는 0.85 °이다. 분기점 (16) 을 갖지 않는 변 (14b) 과, 주로 (14) 의 도광 방향 (17) 이 이루는 각도 (θ) 는 0.7 °이다. In the branching point 16 where each branch path 15 mainly branches from the side 14 on the side 14a which has the branching point 16, the main part 14 and the light guide direction 17 of the main part 14 respectively form | forms. Angle (

) Is 0.85 °. Angle (theta) which the side 14b which does not have branching point 16, and mainly the light guide direction 17 of 14 is 0.7 degrees.

Next, the transparent concave mold (quartz agent) was arrange | positioned so that the whole core might be covered, and the cladding layer forming varnish was filled in the inside of the concave mold. After irradiating 2,000 mJ / cm <2> ultraviolet-rays from the surface (outer side) of a recessed mold, it heat-processed at 80 degreeC for 5 minutes, and peeled the recessed mold after that.

This formed the over cladding layer of thickness 1mm. The side cross-sectional shape of the front end of the over cladding layer is a convex lens (curvature radius 1.5 mm) of approximately 1/4 arc shape. The refractive index of the over cladding layer at a wavelength of 830 nm was 1.510.

Next, the light emitting element (VCSEL by Optowell company) which emits light of wavelength 850nm is optically couple | bonded through the ultraviolet curable resin, and the optical waveguide with a light emitting element was produced in the edge part of the core side.

[Example 2]

) 를 0.1 °로 하였다. 또, 분기점 (16) 을 갖지 않는 변 (14b) 과, 주로 (14) 의 도광 방향 (17) 이 이루는 각도 (θ) 를 0.4 °로 하였다. 이 이외에는 실시예 1 과 동일하게 하여, 발광 소자가 형성된 광 도파로 (10) 를 제조하였다. The angle formed by the light guide direction 17 of the main body 14 and the main body 14 mainly at the branching point 16 at which the branch mask 15 branches mainly from the branch 14 by changing the photomask.

) Was 0.1 °. Moreover, the angle (theta) which the side 14b which does not have the branch point 16, and the light guide direction 17 of mainly 14 was made into 0.4 degrees. In the same manner as in Example 1 except this, an optical waveguide 10 in which a light emitting element was formed was manufactured.

Example 3

) 를 1.4 °로 하였다. 또, 분기점 (16) 을 갖지 않는 변 (14b) 과, 주로 (14) 의 도광 방향 (17) 이 이루는 각도 (θ) 를 1.0 °로 하였다. 이 이외에는 실시예 1 과 동일하게 하여, 발광 소자가 형성된 광 도파로 (10) 를 제조하였다. The angle formed by the light guide direction 17 of the main body 14 and the main body 14 mainly at the branching point 16 at which the branch mask 15 branches mainly from the branch 14 by changing the photomask.

) Was set to 1.4 °. Moreover, the angle (theta) which the side 14b which does not have the branch point 16, and the light guide direction 17 of mainly 14 was made into 1.0 degree. In the same manner as in Example 1 except this, an optical waveguide 10 in which a light emitting element was formed was manufactured.

Comparative Example 1

The photomask was changed and the core 43 which mainly contains 44 and the 274 branch path 46 shown in FIG. 8 was formed. The branch point 42 was mainly arranged so as to be orthogonal to the light guiding direction 45 of the 44. The maximum width W2 of the main 44 of the core 43 is 8,205 μm, the height is 50 μm, the width of the branch passage 46 is 15 μm, the height is 50 μm, and the gap between adjacent branch passages 46 is present. 47 is 15 micrometers (* 273 pieces). In the same manner as in Example 1 except this, an optical waveguide 40 in which a light emitting element was formed was manufactured.

Comparative Example 2

) 를 0.05 °로 하였다. 또, 분기점 (16) 을 갖지 않는 변 (14b) 과, 주로 (14) 의 도광 방향 (17) 이 이루는 각도 (θ) 를 0.2 °로 하였다. 이 이외에는 실시예 1 과 동일하게 하여, 발광 소자가 형성된 광 도파로 (10) 를 제조하였다. The angle formed by the light guide direction 17 of the main body 14 and the main body 14 mainly at the branching point 16 at which the branch mask 15 branches mainly from the branch 14 by changing the photomask.

) Was set to 0.05 °. Moreover, the angle (theta) which the side 14b which does not have the branch point 16, and the light guide direction 17 of mainly 14 was made into 0.2 degrees. In the same manner as in Example 1 except this, an optical waveguide 10 in which a light emitting element was formed was manufactured.

[Evaluation 1]

Example 1? Table 1 shows the maximum width of mainly the core of the optical waveguide in which the light emitting elements of 3 and Comparative Example 1 were formed. Example 1? It is understood that the optical waveguide in which the light emitting element of 3 is formed is 40% or more narrower in the maximum width of the core mainly than the optical waveguide in which the light emitting element of Comparative Example 1 is formed.

Configuration

) (°)Angle (

) (°) Angle (θ) (°) Maximum width of mainly (㎛) Example 1 1 0.85 0.7 3,239 Example 2 1 0.1 0.4 1,863 Example 3 1 1.4 1.0 4,614 Comparative Example 1 8 - - 8,205

[Evaluation 2]

<Manufacture of an optical waveguide in which a light receiving element is formed>

The photomask was changed, and the light receiving side optical waveguide 32 was manufactured by making the core 31 into the structure of FIG. The number of cores 31 is 274. The width of the core 31 is 15 μm and the height is 50 μm. A light receiving side optical waveguide 32 was manufactured in the same manner as in Example 1 except for this.

An optical waveguide in which a light receiving element 33 (a CMOS linear sensor array manufactured by Hamamatsu Photonics) is optically coupled to an end of the core 31 of the light receiving side optical waveguide 32 via an ultraviolet curable resin, 30) was prepared.

<Production of Sample for Light Intensity Measurement>

In order to measure light intensity, as shown in FIG. 6, the manufactured optical waveguide 10 in which the light emitting element was formed and the optical waveguide 30 in which the light receiving element was formed were directly opposed without interposing the coordinate input region. The control unit of the light receiving element 33 was connected to a USB mounting unit (manufactured by National Instruments, Inc.) via a flexible printed circuit board, and connected to a computer capable of monitoring light intensity through a USB port.

Light of wavelength 850 µm and intensity of 7 µW was emitted from the light emitting element 11 of the optical waveguide 10 in which the light emitting element was formed. Light passed through the light emitting side optical waveguide 12 and the light receiving side optical waveguide 32 to reach the light receiving element 33, and the light intensity distribution shown in FIG. 7 was detected. The light intensity distribution shown in FIG. 7 is an example.

Table 2 shows the deviation (maximum value-minimum value) of the light intensity in the effective region (region except the rising and falling portions) of the obtained light intensity distribution. Example 1? It is understood that the optical waveguide in which the light emitting element of 3 is formed has superior uniformity of light emitted from each branch path than the optical waveguide in which the light emitting element of Comparative Example 2 is formed.

)
(°)
Angle (

)
(°)
Angle (θ)
(°) Light intensity detected at the light receiving element (relative value) Maximum value Minimum value Max-Min Example 1 0.85 0.7 3.5 2.2 1.3 Example 2 0.1 0.4 3.3 1.8 1.5 Example 3 1.4 1.0 3.3 2.0 1.3 Comparative Example 2 0.05 0.2 3.5 0.7 2.8

[How to measure]

Refractive index

The varnish for cladding layer formation and the varnish for core formation were each formed into a film by spin coating on the silicon wafer, the sample for refractive index measurement was produced, and the refractive index was measured using the prism coupler (made by Cylon Co., Ltd.).

[Core width, core height]

The prepared optical waveguide was cut in section using a die cutter (DAD522, manufactured by DISCO), and the cut surface was observed with a laser microscope (manufactured by Keyence Corporation) to measure the core width and the core height.

Although the use of the optical touch panel 20 using the optical waveguide 10 in which the light emitting element of the present invention is formed is not particularly limited, it is preferably used in a PC monitor, ATM, game machine, tablet PC and the like.

10: optical waveguide in which the light emitting element is formed
11: light emitting element
12 light emitting waveguide
13: core
14: mainly
14a: side
14b: side
14c: end
15: by branch
16: fork
17: light guiding direction
18: cladding layer
19: light
20: optical touch panel
21: light emitting waveguide
22: light emitting element
23: coordinate input area
24: light receiving side optical waveguide
25: light receiving element
26 rays
30: optical waveguide in which the light receiving element is formed
31: core
32: light receiving side optical waveguide
33: light receiving element
34: cladding layer
40: optical waveguide in which light emitting element is formed
41: light emitting element
42: fork
43: core
44: mainly
45: light guiding direction
46: each quarter
46: by branch
47: gap

Claims (2)

An optical waveguide in which a light emitting element having a light waveguide including a light emitting element and a core for guiding light from the light emitting element and generating a plurality of light rays,
The core has a main branch and a plurality of branching paths branched from a plurality of branching points from the main,
The main passage has a side having the branch point and a side not having the branch point opposite to the side,
The plurality of branching points are formed on a straight line substantially parallel to the main light guide direction,
The main width becomes narrower as it moves away from the light emitting element,
At a branch point where the branching path branches from the main road, the angle between the main road and the light guide direction of the main road (

) Is 0.1 °? 2.0 °,
The angle θ formed between the edge not having the branch point of the main line and the light guide direction of the main line is 0.3 °? Optical waveguide, in which a light emitting element is formed, which is 1.7 °. The optical touch panel provided with the optical waveguide in which the light emitting element of Claim 1 was formed.

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