JP2007240520A - Optical position sensor component, optical position sensor, and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical position sensor component and an optical position sensor, using a waveguide of high photoconductivity, and a manufacturing method therefor. <P>SOLUTION: This optical position sensor component is provided with a light guide part 13 for input and a photoreceiving light guide part 23. The light guide part 13 comprises polymer waveguides for setting light emitted from a near infrared ray source 11 incident, and for emitting the incident light from a plurality of terminal ends to collimating lenses 14. The photoreceiving light guide part 23 comprises a plurality of polymer waveguides for setting light emitted from the light guide part 13 incident from the terminal ends, and for emitting the incident light to photoreception elements 21. A cured resin of a photosensitive resin composition is used in a core portion for constituting the polymer waveguide, in the light guide part 13 and the photoreceiving light guide part 23. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical position sensor component, an optical position sensor, and a manufacturing method thereof.

  Conventional position sensor components are made by covering a display screen with a resistive film, a capacitive film, or a film deposited or coated with a conductive material. For example, Patent Document 1 discloses a conventional technique. However, in this method, since it is covered with a film that does not have a display function, it is necessary to increase the light intensity of the screen in order to obtain the same luminance as usual. In order to increase the light intensity of the screen, energy consumption increases.

However, in portable information terminals and laptop computers where such position sensor components are frequently used, the amount of battery that can be used is often determined, and a position sensor that consumes too much electricity is not preferable. .
US Patent Application Publication No. 2006/002655

  Therefore, the present invention has been made to solve such problems, and provides an optical position sensor component, an optical position sensor using a waveguide having high photoconductivity, and a manufacturing method thereof. With the goal.

  One aspect of the optical position sensor component of the present invention includes an input light guide and a light receiving light guide. The input light guide unit is made of a polymer waveguide that receives light emitted from a near-infrared light source and emits the incident light from a plurality of ends to a collimating lens. The light receiving light guide unit includes a plurality of polymer waveguides that allow light emitted from the input light guide unit to enter from a terminal and emit the incident light to a near-infrared light receiving element. Moreover, in the light guide for input and the light guide for light reception, the core portion constituting the polymer waveguide is made of a cured product of a photosensitive resin composition.

  In addition, an aspect of the optical position sensor of the present invention includes an input optical component, and a light receiving optical component that is disposed to face the input optical component on a flat substrate. The input optical component includes a near-infrared light source, a plurality of collimating lenses, an end portion that receives light emitted from the near-infrared light source, and incident light for the plurality of collimators. An input light guide unit including a polymer waveguide having a plurality of ends emitting to the lens is included. The light receiving optical component includes a plurality of near-infrared light receiving elements and a terminal for receiving the light emitted from the input light guide unit, and another light emitting the incident light to the plurality of near-infrared light receiving elements. A light-receiving light-guiding unit including a plurality of polymer waveguides having ends. Moreover, in the light guide for input and the light guide for light reception, the polymer waveguide has a core portion made of a cured product of a photosensitive resin composition.

  Furthermore, one aspect of a method for manufacturing an optical position sensor includes the following steps. A step of producing a light guide for input composed of a polymer waveguide having one end and a plurality of ends, and a light guide for light reception composed of a plurality of polymer waveguides by curing the photosensitive resin composition. . Disposing lenses for collimating light at a plurality of ends of the light guide for input; Disposing a near-infrared light source at an end of the input light guide; Disposing a near-infrared light receiving element in each of the polymer waveguides constituting the light receiving light guide;

  In one aspect of the method of manufacturing the optical position sensor, the step of curing the photosensitive resin composition is a method of manufacturing a core portion constituting the polymer waveguide by an alkali development type photolithographic method. It is.

  The photosensitive resin composition contains (A) a copolymer having at least hydroxyalkyl (meth) acrylate and (meth) acrylic acid as monomers, and one or more (meth) acryloxy groups in the molecule. An adduct with an isocyanate compound, (B) a compound containing one or more ethylenically unsaturated groups in the molecule (excluding the component (A) above), and (C) a photopolymerization initiator It is.

  Furthermore, the component (A) is one or more monomers selected from ethylenically unsaturated-containing aromatic compounds, alicyclic alkyl (meth) acrylates, and optionally branched alkyl (meth) acrylates, and It is an adduct of a copolymer having hydroxyalkyl (meth) acrylate and (meth) acrylic acid as monomers and an isocyanate compound containing one or more (meth) acryloxy groups in the molecule.

  According to one aspect of the optical position sensor component, the optical position sensor, and the manufacturing method thereof according to the present invention, the core portion of the light guide portion is a cured product of the photosensitive resin composition. As the optical position sensor can detect the position with high sensitivity, the light can be efficiently combined with the light and the light with the light guide and the light receiver.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. This embodiment shows an aspect in which the present invention is applied to an optical position sensor and a manufacturing method thereof. FIG. 1 is a diagram showing a schematic structure showing an example of an optical position sensor according to an embodiment of the present invention. FIG. 2 is a schematic structural view showing another example of the optical position sensor according to the embodiment of the present invention.

  The optical position sensor shown in FIG. 1 includes an input optical component 10 and a light receiving optical component 20. The input optical component 10 includes a near-infrared light source 11, an input light guide 13, and a plurality of collimating lenses 14. The light receiving optical component 20 includes a plurality of near-infrared light receiving elements 21, a light receiving light guide 23, and a collimating lens 24. The input light guide unit 13 includes the light emitting unit 12, and the light receiving light guide unit 23 includes the light receiving unit 22.

  In the optical position sensor component shown in FIG. 1, the light emitting unit 12 and the light receiving unit 22 are made of polymer waveguides (polymer optical waveguides) constituting each light guide unit. The position of the optical position sensor component (the input light guide unit 13 and the light receiving light guide unit 23) is determined based on whether light from each light emitting unit 12 reaches each light receiving unit 22 or not. The input optical component 10 causes light from the light emitting unit 12 to enter the optical waveguide. The light receiving optical component 20 sends light from the optical waveguide to the light receiving unit 22. The arrows in FIGS. 1 and 2 indicate optical paths in the optical waveguide.

  In the input optical component 10 in the optical position sensor component, a near-ultraviolet light source 11 is disposed at a flat (planar substrate) end, and a collimating lens 14 is disposed at a branch end (end). At this time, for example, a sapphire laser is used as the light source 11. The input optical component 10 uses a polymer waveguide having a branched structure as the input light guide 13. For example, the input light guide unit 13 is a polymer guide having an end portion that receives light emitted from a near-infrared light source, and a plurality of ends that emit the incident light to the plurality of collimating lenses 14. It consists of a waveguide. The light emitted from the light source 11 is branched and guided in the waveguide. As shown in FIG. 1, these light guides 13 for input may branch light from one light emitting source 11 in each light emitting unit 12, or emit light as shown in FIG. The light may be directly branched from the source 11 and the branched light may be guided to the respective light emitting units 12.

The light receiving optical component 20 in the optical position sensor component includes a near infrared light receiving element 21 and a collimating lens 24 at the branch end. At this time, for example, a photodiode is used as the light receiving element 21. The light receiving optical component 20 uses a plurality of polymer waveguides as the light receiving light guide 23. For example, the light receiving light guide 23 has a plurality of high ends having a terminal that receives the light emitted from the light guide 13 for input and another terminal that outputs the incident light to the plurality of near-infrared light receiving elements 21. It consists of a molecular waveguide. The light receiving element 21 at this time is arranged for each polymer waveguide as shown in FIG. By doing so, the light receiving element 21 recognizes the position.
Further, the input optical component 10 and the light receiving optical component 20 described above are arranged to face each other on a flat substrate. Therefore, the input light guide unit 13 and the light receiving light guide unit 23 are also arranged to face each other. For example, when the input optical component 10 is disposed along the left end and the lower end of the optical position sensor component, the light receiving optical component 20 is disposed along the right end and the upper end.

  1 and 2, the light receiving optical component 20 shows a case where a collimating lens 24 is arranged, but the collimating lens 24 is not necessarily arranged. When light arriving from the collimating lens 14 disposed on the input optical component 10 enters the light receiving light guide 23 almost linearly, the light emitted from the light emitting part 12 reaches the light receiving part 22. To do. For this reason, even if the collimating lens 24 is not disposed, it can function as an optical position sensor.

  The polymer waveguide is disposed in a state where the core portion is sandwiched between the lower clad layer and the upper clad layer. The characteristic of this polymer waveguide is that the relative refractive index difference between the core portion and the cladding layer is 1 to 4% (in this specification, for example, “1 to 4” is “1 to 4”) ).

  In the optical position sensor component according to the present embodiment, the core portion constituting the polymer waveguide includes (A) at least a copolymer of hydroxyalkyl (meth) acrylate and (meth) acrylic acid, and a molecule. Adducts with isocyanate compounds containing one or more (meth) acryloxy groups, (B) compounds containing one or more (meth) acryloyl groups in the molecule (excluding the component (A) above) And (C) a cured product of a photosensitive resin composition containing a photopolymerization initiator.

  The copolymer for producing the component (A) is an ethylenically-unsaturated-containing aromatic compound, an alicyclic alkyl (meth) acrylate, or an alkyl (which may be branched) in order to obtain high waveguide characteristics. Copolymerization with (meth) acrylate or the like is preferable. In addition, when using it for a clad layer, since it is not necessary to provide alkali developability, it is not necessary to copolymerize (meth) acrylic acid.

  The photosensitive resin composition may be dissolved in an organic solvent (ethyl lactate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl isobutyl ketone, methyl amyl ketone). The viscosity of the composition at this time is preferably about 200 mPa · s (millipascal · second) to 2000 mPa · s at 25 ° C. In addition, a polymerization inhibitor, a sensitizer, and a surfactant can be added as necessary.

  Furthermore, the physical properties of the cured product of the photosensitive resin constituting the core portion are such that the refractive index at a wavelength of 824 nm (25 ° C.) is 1.51 or more and 1.56 or less, and the material loss is 0.05 dB / cm to 0.00. It is preferable that 30 dB / cm and the glass transition temperature be 55 ° C to 180 ° C.

Then, the manufacturing method of an optical position sensor is demonstrated. FIG. 3 is a flowchart showing an example of a manufacturing method of the optical position sensor.
First, an input light guide 13 made of a polymer waveguide having one end and a plurality of ends, and a light receiving light guide 23 made of a plurality of polymer waveguides having two ends are made of a photosensitive resin. The composition is cured to prepare (S11). Next, light collimating lenses 14 are arranged at a plurality of ends of the input light guide 13 (S13). A near-infrared light source 11 is arranged at the terminal (end) (S15). A near-infrared light receiving element 21 is arranged at each end of the polymer waveguide constituting the light receiving light guide 23 (S17). In this way, an optical position sensor including the input optical component 10 and the light receiving optical component 20 is manufactured. About the specific manufacturing method of the photosensitive resin composition, a specific example is demonstrated in an Example. FIG. 3 shows an example of a method for manufacturing an optical position sensor, and the present invention is not limited to this procedure.

Example 1
A flask equipped with a dry ice / methanol reflux was purged with nitrogen, and then 3 g of 2,2′-azobisisobutyronitrile as a photopolymerization initiator and 115 g of propylene glycol monomethyl ether acetate as an organic solvent were added. Stir until dissolved. Subsequently, 20 g of hydroxyethyl methacrylate, 10 g of dicyclopentanyl methacrylate, 25 g of styrene, 10 g of methacrylic acid, and 35 g of n-butyl acrylate were added, and stirring was started gently. Thereafter, the temperature of the solution was raised to 80 ° C., and polymerization was carried out at this temperature for 6 hours.

  Thereafter, 0.13 g of di-n-butyltin dilaurate and 0.05 g of 2,6-di-t-butyl-p-cresol were charged into the obtained solution, and 23.7 g of 2-methacryloxyethyl isocyanate was stirred. Was added dropwise so that the temperature was kept at 60 ° C. or lower. After completion of the dropwise addition, the mixture was reacted at 60 ° C. for 5 hours to obtain a polymer solution having a methacryl group in the side chain. Thereafter, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, it was redissolved in tetrahydrofuran having the same mass as the coagulated product and coagulated again with a large amount of hexane. After performing this re-dissolution-coagulation operation three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain the intended polymer A-1.

  The composition for the core is 100 g of the above-mentioned polymer A-1, 30 g of tribromophenol ethoxy acrylate (Daiichi Kogyo Seiyaku Co., Ltd., New Frontier BR-31), photo radical polymerization initiator (trade name “Irgacure 369”, 3 g of Ciba Specialty Chemicals) and 110 g of ethyl lactate were uniformly mixed. In addition, the cladding composition is composed of 100 g of the polymer A-1 described above, 30 g of trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., TMP3A), a photo radical polymerization initiator (trade name “Irgacure 369”, Ciba 3 g of Specialty Chemicals) and 110 g of ethyl lactate were uniformly mixed.

(A) Formation of lower clad layer The clad composition was applied onto the surface of the substrate with a slit coater, and pre-baked at 100 ° C. for 60 minutes using an oven to form a coating film. Next, the coating film made of the cladding composition was irradiated with ultraviolet light having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds to be photocured, thereby forming a lower cladding layer having a thickness of 50 μm.

(B) Formation of core part Next, the composition for cores was apply | coated with the slit coater on the lower clad layer, and the coating film was formed. The formed coating film was pre-baked using an oven at 100 ° C. for 60 minutes to form a coating film having a thickness of 50 μm. The coating film was cured by irradiating ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds through a photomask having a predetermined pattern. Next, the substrate having the cured coating film was immersed in a developer composed of a 2.38 wt% tetramethylammonium hydroxide aqueous solution for 5 minutes to dissolve the unexposed portion of the coating film. Then, after rinsing with running water for 2 minutes, it was dried to form a core part. As described above, the core portion is formed by an alkali development type photolithographic method in which the core portion is exposed and developed with an alkali developer.

(C) Formation of upper clad layer Next, a clad composition is applied to the upper surface of the lower clad layer having the core portion by a slit coater to form a coating film, and using an oven at 100 ° C. for 60 minutes. The coating was pre-baked. Thereafter, an upper clad layer was formed by irradiating ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds.

  It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

It is the structure schematic of the optical position sensor which concerns on this Embodiment. It is another example of the structure schematic of the optical position sensor which concerns on this Embodiment. It is a flowchart which shows an example of the manufacturing method of the optical position sensor which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Input optical component 11 Light emission source 12 Light emission part 13 Input light guide part 14 Lens 20 Light reception optical part 21 Light receiving element 22 Light reception part 23 Light reception light guide part 24 Lens

Claims (7)

A light guide for input composed of a polymer waveguide that enters light emitted from a near-infrared light source and emits the incident light from a plurality of ends to a collimating lens;
A light-receiving light-guiding unit composed of a plurality of polymer waveguides that enter the light emitted from the input light-guiding unit from the end and emit the incident light to the near-infrared light-receiving element,
An optical position sensor component in which a core portion constituting the polymer waveguide is a cured product of a photosensitive resin composition. The photosensitive resin composition is
(A) an adduct of a copolymer having at least hydroxyalkyl (meth) acrylate and (meth) acrylic acid as monomers, and an isocyanate compound containing one or more (meth) acryloxy groups in the molecule;
(B) a compound containing one or more ethylenically unsaturated groups in the molecule (however, the above component (A) is excluded),
(C) a photopolymerization initiator,
The optical position sensor component according to claim 1, comprising:   The component (A) is one or more monomers selected from ethylenically unsaturated-containing aromatic compounds, alicyclic alkyl (meth) acrylates, and optionally branched alkyl (meth) acrylates, and hydroxyalkyl The optical component according to claim 2, which is an adduct of a copolymer containing (meth) acrylate and (meth) acrylic acid as a monomer and an isocyanate compound containing one or more (meth) acryloxy groups in the molecule. Type position sensor parts. Input optical components,
The optical component for input and the optical component for light receiving disposed opposite to the flat substrate,
The input optical component is:
A near-infrared light source;
Multiple collimating lenses,
An input light-guiding unit composed of a polymer waveguide having an end portion for incident light emitted from the near-infrared light source and a plurality of ends for emitting incident light to the plurality of collimating lenses; Including
The light receiving optical component is:
A plurality of near-infrared light receiving elements;
A light receiving light guide unit composed of a plurality of polymer waveguides having a terminal for entering the light emitted from the light guiding unit for input and another terminal for emitting the incident light to the plurality of near-infrared light receiving elements. And including
An optical position sensor in which a core portion constituting the polymer waveguide is a cured product of a photosensitive resin composition. A step of producing a light guide for input composed of a polymer waveguide having one end and a plurality of ends, and a light guide for light reception composed of a plurality of polymer waveguides by curing the photosensitive resin composition. When,
Arranging collimating lenses at a plurality of ends of the input light guide; and
Disposing a near-infrared light source at the end;
Arranging a near-infrared light receiving element in each of the polymer waveguides constituting the light receiving light guide; and
The manufacturing method of the optical position sensor which has this.   6. The optical position sensor according to claim 5, wherein in the step of curing the photosensitive resin composition, the core portion constituting the polymer waveguide is manufactured by an alkali development type photolithographic method. Manufacturing method. The photosensitive resin composition is
(A) Adduct (B) molecule comprising a copolymer having at least hydroxyalkyl (meth) acrylate and (meth) acrylic acid as monomers, and an isocyanate compound containing one or more (meth) acryloxy groups in the molecule Compounds containing one or more ethylenically unsaturated groups (excluding the component (A) above)
(C) The manufacturing method of the optical position sensor of Claim 5 or 6 containing a photoinitiator.

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