JPH09212303A - Photoconductor and optical position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To gain an enough distance between a light emitting element and a receiving element by adopting miniaturized chip type light emitting and receiving elements with a low output. SOLUTION: Chip type light emitting elements 32 and chip type light receiving elements 33 are mutually opposedly loaded on a substrate 31 in a plane. A frame-like photoconductor 21 for guiding light is fitted to the substrate 31. The photoconductor 21 is integrally formed and many slits for preventing the diffusion and creeping of light and removing a transmission loss are formed in the outer periphery of the photoconductor 21 and light emitting parts 15 and light receiving parts 16 are formed by the slits 22. Reflection parts 23 are formed on respective light emitting and receiving parts 15, 16 so that light from the light emitting element 32 is made incident from the lower face of the light emitting part 15 and the incident light is received by the light receiving element 33 from the lower face of the light receiving part 16. Gap parts 25 for reducing the intrusion of disturbant light into the photoconductor 21 are formed on the ways between the light emitting and receiving parts 15, 16, one face of each gap part 25 is formed in a curved surface 26 to form a light converging part 24 for converging light upon the light emitting and receiving parts 15, 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide used in an optical touch panel and an optical position detecting device, and more particularly to a chip type which has a small amount of received and emitted light but is advantageous in mounting cost of parts and device thickness. The present invention makes it possible to use the light emitting / receiving element, reduce the power consumption of the device, reduce external noise, and increase the size.

[0002]

2. Description of the Related Art As shown in FIG. 7, a pair of light emitting elements 2 and light receiving elements 3 are separated by a predetermined distance, and a plurality of pairs are arranged to form a detection panel 1. The position or presence or absence of the object 4 on the optical touch panel surface 5 is detected by sequentially scanning the elements 3 and detecting whether or not the light emitted from each light emitting element 2 toward the corresponding light receiving element 3 is blocked by the object 4. There is known an optical position detecting device for detecting the.

As shown in FIG. 8, the light receiving and emitting elements 2 and 3 arranged on the detection panel 1 are of a relatively spindle type and a large spindle type light receiving and emitting element 6 (FIG. 8A,
(B)) or a side-view type light emitting / receiving element 7 (FIG. 8 (c)) having a light emitting / receiving portion on its side surface is generally used as a discrete type having a lead terminal 8.

However, in the discrete type light emitting / receiving elements 6 and 7 formed by resin-sealing the bare chip mounted on the stem, the distance between the light emitting / receiving elements is large because the amount of light emitting / receiving is large, but the lead terminal 8 is used. Since it is necessary to insert the solder into the holes provided in the board 9 and then solder it,
It is troublesome to attach to, and the mounting cost of parts is high. Further, since the outer diameter is large, the mounting thickness becomes thick, which is not suitable for thinning, and the device cannot be downsized. Furthermore, it consumes a large amount of power and cannot be used for portable applications.

Therefore, in recent years, as a small-sized device, as shown in FIG. 9, a chip-type light emitting / receiving element 10 having a small amount of emitted light is emitted.
Started to be used. This chip type light emitting / receiving element 10
Is advantageous in terms of mounting surface and thinning because it has no leads and can be directly surface-mounted on the substrate 9, and it is possible to downsize the device due to its small size and low power consumption. Can be used. Further, unlike the discrete type, the mounting surface can be selected without bending the leads, and the light emitting / receiving surface can be easily laid sideways (see FIG. 9).
(A)), and can be turned upward (Fig. 9)
(B)).

Although an infrared light emitting / receiving element is usually used, the visible light wavelength component cannot be ignored, so in actual use,
As shown in FIG. 10, the visible light cut filter 13 is arranged on the front surface of the light receiving and emitting element 10 or has a structure in which it is covered.
I try not to react to visible light.

[0007]

By the way, in the chip type light receiving and emitting element, even if the same chip type is used, the concave mirror 1
There is a concave-mirror-equipped type light emitting / receiving element (FIG. 9 (c)) in which the bare chip 12 is attached to the No. 1 and a bare type (FIG. 9 (d)) receiving / emitting element that includes the bare chip 12 only. Since the optical output with a concave mirror is large to some extent, it is optimal for a small device, but it is very expensive in structure, and it is necessary to select one with a particularly large amount of light emission and reception. Also,
On the other hand, the one without the concave mirror is more attractive because it is smaller and cheaper, but its optical output is considerably weaker than that with the concave mirror, so that it is opposed to receive a light signal of a detectable level. There is no choice but to reduce the distance between the light emitting elements, and even such a small position detection device cannot secure a necessary touch panel area with such a small distance. In particular, as shown in FIG. 9B, when the light emitting / receiving surface is directed upward and light is reflected to reach the opposing light emitting / receiving element, a light amount loss occurs. Was difficult to put into practical use.

Further, the amount of light in the chip type is considerably smaller than that in the discrete type whether it is a bare chip with a concave mirror or a bare chip without a concave mirror, so that the influence of diffusion or disturbance on the optical path from the light emitting element to the light receiving element. Therefore, it is necessary to select a light emitting element with a large light output that withstands it or a light receiving element with a large light receiving ability,
The sorting work is very troublesome and the yield is poor. Further, since the visible light cut filter is separately required, the advantage of the chip type in terms of thickness cannot be utilized. In addition, it has not been possible to cope with a large-sized device in which the distance between the light receiving and emitting elements facing each other is long.

An object of the present invention is to solve the above-mentioned problems of the prior art and to receive and emit light while adopting a small chip type light emitting and receiving element which is small in light emitting and receiving amount but advantageous in mounting cost and device thickness. An object of the present invention is to provide a light guide body and an optical position detecting device which can maintain a sufficient distance between elements and can be put to practical use.

[0010]

A first aspect of the present invention is a frame-shaped light guide that is mounted around the surface of an optical touch panel and is transparent to the wavelength of light used, and guides light from a light emitting element. And a plurality of pairs of light-receiving units that emit light from the light-emitting units and guide light from the light-emitting units to the light-receiving elements are integrally formed, and the light-receiving units receive light at least at the boundary between the light-emitting units. A slit is formed to prevent light from sneaking into the light-receiving part, and the light-emitting part is provided with a light-collecting part that collects the light emitted to the light-receiving part and the light-receiving part collects the light to be guided to the light-receiving element. It is a thing. As in the first invention, a plurality of pairs of a light emitting portion that guides the light from the light emitting element and emits the light to the opposite light receiving portion and a light receiving portion that receives the light from the light emitting portion and guides the light to the light receiving element are integrally formed. In this case, the structure can be simplified and the manufacturing becomes easy as compared with the case where they are formed separately. Further, when a slit is provided at least at the boundary between the light emitting unit and the light receiving unit, by restricting the light emitted from the light emitting unit from passing through the light guide to the light receiving unit on the opposite side with the slit, It is possible to effectively prevent the wraparound light from malfunctioning due to coupling with the light receiving element. In this case, if slits are also provided between the light emitting units and between the light receiving units, the diffusion of light in each light emitting unit and each light receiving unit can be regulated by the slit, so that the light amount from the light receiving unit to the corresponding light emitting unit can be controlled. Can be effectively prevented.

Further, if the light emitting portion is provided with a light collecting portion for collecting the light emitted to the light receiving portion and the light receiving portion for collecting the light guided to the light receiving element, the light collecting portion collects the light. Since light can be efficiently radiated from the light emitting unit to the light receiving unit, the light can be sent to the light receiving unit without reducing the light amount, and the light diffused in the process from the light emitting unit to the opposite light receiving unit is incident on the light receiving unit. After that, the light can be efficiently collected by the light collecting unit. Therefore, even if a chip type light emitting element with a small light output is used, a light emitting element with a particularly large light output,
There is no need to select a light receiving element having a large light receiving ability. Further, since a large amount of detected light can be obtained, the distance between the light emitting portion and the light receiving portion can be extended, and the invention can be applied to a large size optical position detecting device while using a small chip type light receiving and emitting element.

A second aspect of the present invention is a frame-shaped light guide that is mounted around the surface of the optical touch panel and is transparent to the wavelength of the light used, and guides light from the light emitting element to the opposite light receiving portion. A plurality of pairs of a light-emitting portion that emits light and a light-receiving portion that receives light from the light-emitting portion and guides the light to the light-receiving element are integrally formed, and light wraps around from the light-emitting portion to the light-receiving portion at least at the boundary between the light-emitting portions. To form a slit for preventing the light emitting portion and the light receiving portion from interposing a layer having a different refractive index in order to refract the disturbance light that has entered the light emitting portion or the light receiving portion and to escape it to the outside of the light emitting portion or the light receiving portion. A cavity is formed, and the inner surface of the cavity is formed into a curved surface, and the light emitted to the light receiving section is condensed on one side of the light emitting section side cavity and is guided to the light receiving element on one side of the light receiving section side cavity. The light collecting portions that collect light are integrally provided.

As in the second aspect of the invention, the light emitting portion and the light receiving portion are provided with layers having different refractive indexes in order to refract the disturbance light that has entered the light emitting portion or the light receiving portion and to escape it to the outside of the light emitting portion or the light receiving portion. In the case of forming a void portion for, because the void portion suppresses the entry of ambient light such as sunlight, the ambient light is
Since it is less likely that the light emitting element as a light source is affected or the light receiving element receives the light, a malfunction due to ambient light can be less likely to occur. In addition, the inner surface of the cavity is curved to have a lens effect, and the light emitted to the light receiving section is condensed on one side of the light emitting section side cavity and is guided to the light receiving element on one side of the light receiving section side cavity. When the light collecting portions that collect light are integrally provided, the light collecting portions can be formed at the same time when the voids are formed, so that the configuration and the manufacturing can be simplified.

In a third aspect based on the second aspect, the ambient light is reflected on the inner side surface of the light guide forming the light emitting surface of the light emitting portion or the light receiving surface of the light receiving portion so that the ambient light emits the light. The taper is formed to prevent it from entering the light receiving portion.

As in the third aspect of the invention, a taper is formed on the inner surface of the light emitting portion or the light receiving portion of the light guide to reflect the ambient light and prevent the ambient light from entering the light emitting portion or the light receiving portion. When it does, malfunction due to ambient light is less likely to occur.

Further, this taper spreads the light emitted from the light emitting portion, reflects the light on the inner surface of the light guide forming the light receiving and emitting surface, and eliminates the optical path entering the light receiving portion.

A fourth aspect of the present invention is the light guide according to any one of the first to third aspects, wherein the light guide further reflects light incident on the light emitting section from a light emitting element provided on the lower surface of the light emitting section. The reflecting portion facing the opposite light receiving portion and the reflecting portion reflecting the light incident on the light receiving portion toward the light receiving element provided on the lower surface of the light receiving portion are integrally provided.

As in the fourth aspect of the invention, the light incident on the light emitting portion from the light emitting element provided on the lower surface of the light emitting portion is reflected and radiated to the opposite light receiving portion, or the light incident on the light receiving portion is reflected. When the reflecting portions that lead to the light receiving element provided on the lower surface of the light receiving portion are integrally provided, the light emitting element and the light receiving element can be overlapped with the light guide body, and the light emitting element and the light receiving element are separated from the light guide body. Since the light emitting element and the light receiving element do not protrude, the device can be downsized as compared with the case where the light emitting element and the light receiving element protrude from the light guide body and light is incident from the side surface of the light guide body. Moreover, since the reflecting portion is formed integrally with the light guide, the configuration can be simplified.

A fifth aspect of the invention is the same as the first to fourth aspects of the invention, wherein a material transparent to infrared light, such as acrylic resin, ABS resin, or polycarbonate, is used as the material. By using the resin as defined in the fifth invention, the light guide body can be inexpensively integrally molded, and the infrared light transmission loss can be reduced.

According to a sixth aspect of the invention, a plurality of light emitting elements and light receiving elements are arranged around the surface of the optical touch panel so as to face each other, and the light from the light emitting elements to the light receiving elements is shielded so that the object An optical position detecting device for detecting a position or presence / absence, wherein the plurality of light emitting elements and light receiving elements mounted in a frame shape around the surface of the optical touch panel and arranged around the surface of the optical touch panel are chip type. And a board on which these are mounted in a plane,
The light guide according to any one of the first to fourth inventions mounted on the substrate.

As in the sixth aspect, when the light emitting element and the light receiving element are formed in a chip type and these are mounted on a substrate in a planar manner, the light emitting element and the light receiving element are formed in a discrete type. However, as compared with the case where the leads are soldered and mounted three-dimensionally, the mounting is easy and the cost can be reduced, and since it is planar, the mounting thickness can be reduced and the device can be downsized. Further, since the light is guided to the light guide body having the light collecting portion, even if a chip type light emitting / receiving element having a weak light output and a small light collecting power is used, the transmission loss can be reduced and the detected light amount can be increased. Therefore, the distance between the light emitting and receiving elements can be extended.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. 1A and 1B are exploded views of the optical position detecting device according to the present embodiment, FIG. 1A is a plan view of a light guide, and FIG. 1B is a plan view of a substrate. FIG. 2 is a perspective view of a main part of the light guide.

The optical position detecting device comprises a substrate 31 mounted in a frame shape around the surface 30 of the optical touch panel,
It is mainly composed of a light guide 21 that guides light that is mounted on the substrate 31 in an overlapping manner.

A plurality of light emitting elements 32 and light receiving elements 33 to be arranged around the surface of the optical touch panel are mounted on the substrate 31 having a rectangular frame shape. In the illustrated example, the light emitting elements 32 are mounted on the upper side and the left side, and the light receiving elements 33 are mounted on the lower side and the right side opposite to them. The light emitting / receiving elements 32, 33 are of a bare chip type without a concave mirror, and these are mounted in a planar manner on the substrate 31 with the light emitting / receiving surface facing upward. Since the light emitting / receiving elements 32 and 33 are mounted on the substrate 31 in a planar shape by using a chip type, the mounting is easy and the cost can be reduced, and the mounting becomes flat and the mounting thickness can be reduced. The light emitting / receiving elements 32 and 33 used are those in the infrared region.

The light guide 21 is provided on the surface 3 of the optical touch panel.
In order to mount it around 0, it is formed in a rectangular frame shape like the substrate 31, and is made of a material transparent to infrared light, such as acrylic resin, ABS resin, or polycarbonate.

A plurality of slits 22 are repeatedly provided on the outer periphery of the light guide body 21, and a plurality of light emitting portions 15 for guiding the light from the light emitting element 32 between the slits 22 and radiating the light to the light receiving portions 16 facing each other. Then, a plurality of light receiving portions 16 that guide the light from the light emitting portion 15 to the light receiving element 33 are formed. The slits 22 prevent the light from wrapping around from the light emitting unit 15 to the light receiving unit 16 and prevent the diffusion of light in each light emitting unit 15 and each light receiving unit 16. The slit 22 is deep on the side of the light emitting unit 15,
Since it is shallow on the 6 side, the shape of the light guide 21 is not symmetrical.

If the slit 22 is provided with only the light sneak-in prevention function, the slit 22 is provided at least at the boundary between the light emitting portion 15 and the light receiving portion 16, that is, at two points A and B shown in FIG. It only needs to be formed. This is because each pair of the light emitting element 32 and the light receiving element 33 is sequentially scanned, and it is not necessary to consider the wraparound of light between the light emitting portions and between the light receiving portions.

The light emitting section 15 receives 90 ° of light incident on the light emitting section 15 from the light emitting element 32 arranged on the lower surface of the light emitting section 15.
Is integrally provided with the reflecting portion 23 that reflects at an angle of, changes to a direction parallel to the touch panel surface 30, and radiates to the facing light receiving portion 16. Further, the light receiving section 16 is also integrally provided with a reflecting section 23 that reflects the light incident on the light receiving section 16 at an angle of 90 ° and directs the light to the light receiving element 33 disposed on the lower surface of the light receiving section 16. These reflection parts 23 can be formed by obliquely cutting the end faces of the light emitting part 15 and the light receiving part 16 that are projected outwardly. If necessary, a reflective film may be applied to the cut surface.

Further, the disturbance light entering the light emitting portion 15 or the light receiving portion 16 is refracted in the middle of the optical paths of the light emitting portion 15 and the light receiving portion 16 of the light guide 21 to refract the light emitting portion 15 or the light receiving portion 16.
A void portion 25 is formed to allow a layer having a different refractive index to intervene in order to escape to the outside. The void 25 is the void 25
In order to keep the inner frame 36 formed on the inside of the light guide 21 connected, it is formed discontinuously. It is advisable to interpose an air layer or another layer having a smaller refractive index than the material forming the light guide 21 in the void portion 25.

Out of the wall surfaces forming the void 25, the outer surface is formed into a curved surface 26 so as to have a lens effect, and the light emitted to the light receiving portion 16 facing the light emitting portion 16 is condensed on one side of the light emitting portion side void 25. Then, the light collecting section 24 that collects the light guided to the light receiving element 33 is integrally provided on one side of the light receiving section side void 25.
Since the light guide body 21 is provided with the light collecting portion 24 to prevent scattering and collect light and increase the amount of detected light, even the bare type weak light element having no concave mirror can reduce the distance between the light receiving and emitting elements facing each other. It can be extended within a practical range. Further, it is not necessary to select a light emitting / receiving element having a large light receiving / emitting amount. In particular, by using the light emitting / receiving element with a concave mirror, the distance can be further extended, so that the present invention can be applied not only to a small detection device but also to a large detection device.

The curved surface 26 of the void 25 is mirror-finished like the flat surface 29 facing it. Further, the curvature of each curved surface 26 is set so that the focal point of the light-collecting section 24 on the light-emitting section side is formed on the light-receiving surface 28 of the light-receiving section 16 and the focal point of the light-collecting section 24 on the light-receiving section side is formed on the light-receiving element 33. decide. In the illustrated example, the inner side surface of the light guide body 21 forming the light emitting surface 27 of the light emitting section 15 or the light receiving surface 28 of the light receiving section 16 is cut so as to be perpendicular to the optical path.

FIG. 2 shows a perspective view of the main configuration of the optical position detecting device described above. As shown in the figure, the light guide body 21 includes a reflection portion 2 of the light emitting / receiving portions 15 and 16.
The light emitting / receiving elements 32, 33 are mounted on the substrate 31 by an appropriate means such as bonding so that the light emitting / receiving elements 32, 33 are arranged on the lower surface on the 3 side. Further, by forming the void portion 25 in the light guide body 21, a continuous inner frame 36 is formed inside the void portion 25. The inner frame 36 reinforces the light guide body 21 and the touch panel surface. It becomes a blindfold around you. The light guide 21 is integrally formed by injection molding or the like.

Now, the light guide 2 is formed on the substrate 31 as described above.
In the optical position detecting device of the present embodiment equipped with No. 1, upward light emitted from the light emitting element 32 mounted on the substrate 31 is emitted from the light emitting unit 15 of the light guide body 21 as shown by an arrow in FIG. The light enters the light guide 21 from the lower surface of the. The light that has entered the light guide 21 is reflected by the reflection section 23, is changed in direction by 90 °, and is guided to the light collection section 24 to be collected. This light collecting part 24
Together with the slit 22, the light is prevented from being scattered. Therefore, a sufficiently large amount of light can be extracted even with weak light. The light condensed by the condensing unit 24 passes through the void 25, exits the light guide 21 from the light emitting surface 27 of the light emitting unit 15, and is emitted toward the light receiving unit 16. Light receiving surface 28 of light receiving unit 16
The light that has entered the light guide body 21 again passes through the void portion 25, reaches the reflecting portion 23, is reflected here, is redirected by 90 °, and is emitted from the lower surface of the light receiving portion 16 to be received. It is detected by the light receiving element 33 arranged on the lower surface of 16.

Here, the disturbance light 20 has an angle shown in FIG.
When the light enters the light receiving portion 16 from the light receiving surface 28 of the light receiving portion 16, the light is bent by the void portion 25, so that the light exits from the light receiving portion 15 before reaching the light receiving element 33. Therefore, unlike the case where there is no space 25, the ambient light 20 that has entered the light guide 21 is less likely to be repeatedly reflected on the upper and lower surfaces of the light guide 21 and reach the light receiving element 33.
As a result, malfunction due to ambient light can be reduced. Note that this effect can also be applied to the light emitting unit 15, and the ambient light 20 incident on the light emitting unit 15 is the light emitting element 3 that is a light source.
2 is less affected.

Further, since the upper portions of the light emitting / receiving elements 32 and 33 are covered with the light emitting portion 15 and the light receiving portion 16 of the light guide 21, ambient light coming from above is shielded by the light emitting portion 15 and the light receiving portion 16. Since ambient light does not directly enter the light emitting / receiving elements 32 and 33, malfunctions due to ambient light can be reduced also from this point.

As described above, according to the present embodiment,
Since the light emitting / receiving element is covered with the light guide to guide the light through the light guide, a visible light cut filter as in the prior art is not required. In addition, a reflector that changes the direction of light in the horizontal direction to a vertical direction, a slit that forms an optical path that prevents the diffusion of light, a condenser that collects light, a void that reduces the intrusion of ambient light, etc. By using an integrally formed light guide, the transmission loss of light can be eliminated, and the amount of detected light can be increased by converging light, and the intrusion of ambient light can be reduced. It is possible to employ a small bare chip type with a low output, and to reduce the mounting cost, make the device thinner, and make it smaller and cheaper than the conventional example that does not use a light guide. Also, since it has low power, it can be driven by a battery and can be used for portable applications. Further, particularly when a chip type light emitting / receiving element having a concave mirror is used, a larger amount of light emitting / receiving light can be obtained and a distance between the light emitting / receiving elements can be set, so that even a chip type light receiving / emitting element can be used in a larger detection device. Can also be applied.

In the above-described embodiment, the light emitting section 1
Although both inner side surfaces of the light guide body 21 constituting the light emitting surface 27 of No. 5 or the light receiving surface 28 of the light receiving unit 16 are cut so as to be perpendicular to the optical path, as shown in FIG. It is preferable that the taper 34 is formed on the inner surface by obliquely cutting so as to form a V shape. By forming the taper 34 in this way, the amount of ambient light entering the light guide 21 from above can be reduced more effectively.

Further, as shown in FIG. 6, the inner surfaces facing each other are cut so that the cross-section thereof has an inverted V shape, and the inner surfaces are tapered 34.
By forming, the light emitted from the light emitting portion spreads and is reflected by the taper in the direction perpendicular to the light emitting portion, and the amount of light entering the light receiving portion can be reduced.

Further, in the above-described embodiment, the light emitting / receiving unit 1
Although the voids 25 are provided in Nos. 5 and 16, as shown in FIG. 5, although the ambient light preventing function is deteriorated, the voids 25 are omitted and a curved surface having a lens effect is formed on the inner surface of the inner frame. By doing so, the inner frame may be used as the light collecting unit 24.

Further, in the above-described embodiment, the reflecting portion 23 is provided on the end faces of the light emitting / receiving portions 15 and 16 so that the light guide 2 can receive light.
Although the light is incident from the lower surface of No. 1 and emitted to the lower surface of the light guide 21, as shown in FIG. 6, the end faces of the light emitting / receiving units 15 and 16 may be vertically cut and the reflecting unit may not be provided. . In that case, the light emitting / receiving elements 32 and 33 need to be arranged not at the lower surface of the light guide body 21 but at the position facing the end surface. According to this, the light guide 21 and the light emitting / receiving element 32,
Since 33 is on the same surface, the device can have a smaller outer diameter than the device in which the light emitting / receiving elements 32 and 33 are arranged on the lower surface of the light guide 21, but the thickness can be reduced.

Further, as shown in the figure, in order to protect the touch panel surface 30, the contact panel 35 covering the touch panel surface 30 is down-set by one step lower than the light emitting / receiving sections 15 and 16 and the light guide 21. It may be formed integrally.

Although the light guide according to the present embodiment is left-right asymmetrical, it may be formed left-right symmetrically for the sake of convenience.

The present invention is most suitable for an optical position detecting device of a navigation system for traffic, for example.

[0044]

Example An optical position detector having the following specifications was produced.

-Chip type light emitting diode: Stanley, model number AN1102W Outline 3mm (W) x 1.5mm (H) x 1.5mm (D) Output 0.8mW / Sr (radiation intensity) -Chip type light receiving diode: Stanley , Model number PS110W External dimensions 3mm (W) × 2mm (H) × 1.5mm (D) Sensitivity 3.5mA (photocurrent) ・ Light guide size: 113.7mm length × 144.2mm width × 3mm thickness ・ Light guide material ： Made by Mitsubishi Rayon Co., Ltd. Acrylite ・ The total thickness of the light guide mounted on the substrate on which the light emitting / receiving elements are mounted: 6.1 mm This allows a sufficient distance between the light emitting / receiving elements even for bare chip type light emitting / receiving elements. It was confirmed that it could be put to practical use.

[0046]

According to the light guide body of the present invention, since the light collecting portion, the void portion, the reflecting portion and the like are formed integrally with the light guide body, the structure is simple and the light transmission loss can be reduced. . Also,
Since the condensing unit is provided, the amount of detected light can be increased. Further, when the slit is provided, it is possible to effectively prevent the light from wrapping around or diffusing. Further, when the void portion and the taper are provided, it is possible to reduce the incidence of disturbance light on the light guide body. When the reflecting portion is provided, the light emitting / receiving element and the light guide can be vertically stacked, so that the device can be downsized.

Further, according to the optical position detecting device of the present invention using the above-mentioned light guide, it is possible to assemble with one touch.
Further, the device can be made thinner, the mounting cost can be reduced, and the device can be made compact and have low power consumption. In addition, it can be driven by batteries and can be used for portable applications. Further, since the distance between the light receiving and emitting portions can be made large, even when a chip type light emitting and receiving element with a small light emitting and receiving amount is used, it can be applied to a large-sized detection device.

[Brief description of drawings]

FIG. 1 is an exploded view of an optical position detection device according to an embodiment of the present invention, (a) is a plan view of a light guide, and (b) is a plan view of a substrate.

FIG. 2 is a perspective view of a main part of the light guide according to the present embodiment.

FIG. 3 is an explanatory diagram of an optical path of the optical position detecting device according to the present embodiment.

FIG. 4 is an explanatory diagram of ambient light when a light emitting surface or a light receiving surface of a light guide of an optical position detecting device according to another embodiment is tapered.

FIG. 5 is a perspective view of a main part of a light guide according to another embodiment.

FIG. 6 is a perspective view of a main part of an optical position detecting device according to another embodiment.

FIG. 7 is a plan view of a conventional optical position detecting device.

FIG. 8 is an explanatory diagram of a discrete type light receiving / emitting element of a conventional example.

FIG. 9 is an explanatory diagram of a chip-type light emitting / receiving element of a conventional example.

FIG. 10 is an explanatory diagram in which a light emitting / receiving element of a conventional example is covered with a visible light cut filter.

[Explanation of Codes] 21 Light Guide 22 Slit 23 Reflecting Part 24 Condensing Part 25 Gap 26 Curved Surface 27 Light Emitting Surface 28 Light Receiving Surface 30 Optical Touch Panel Surface 31 Substrate 32 Light Emitting Element 33 Light Receiving Element

Claims (6)

[Claims] 1. A frame-shaped light guide, which is mounted around the surface of an optical touch panel and is transparent to the wavelength of light used, and which guides light from a light emitting element and radiates the light to an opposite light receiving section. And a plurality of pairs of light-receiving portions that enter the light from the light-emitting portion and guide the light to the light-receiving element, and a slit that prevents light from wrapping around from the light-emitting portion to the light-receiving portion at least at the boundary between the light-emitting portion and the light-receiving portion. And a light-collecting part that collects light emitted to the light-receiving part in the light-emitting part, and collects light guided to the light-receiving element in the light-receiving part. 2. A light guide in the form of a frame, which is mounted around the surface of an optical touch panel and is transparent to the wavelength of light used, and which guides light from a light emitting element and radiates the light to an opposite light receiving portion. And a plurality of pairs of light-receiving portions that enter the light from the light-emitting portion and guide the light to the light-receiving element, and a slit that prevents light from wrapping around from the light-emitting portion to the light-receiving portion at least at the boundary between the light-emitting portion and the light-receiving portion. And forming a void portion in the light emitting portion and the light receiving portion for interposing a layer having a different refractive index in order to refract the ambient light that has entered the light emitting portion or the light receiving portion and escape it to the outside of the light emitting portion or the light receiving portion. Then, the inner surface of the void is curved so that the light emitted to the light receiving unit is condensed on one side of the light emitting unit side void and the light guided to the light receiving element is condensed on one side of the light receiving unit side void. The light guide body is characterized in that each of the light collecting portions is provided integrally. 3. The light guide according to claim 2, wherein ambient light is reflected by the inner surface of the light guide forming the light emitting surface of the light emitting portion or the light receiving surface of the light receiving portion, and the ambient light is emitted by the light emitting portion. Alternatively, a light guide body having a taper formed to prevent it from entering the light receiving portion. 4. The light guide according to claim 1, wherein the light guide further opposes by reflecting light incident on the light emitting section from a light emitting element provided on the lower surface of the light emitting section. A light guide body integrally provided with a reflecting section for directing light to the light receiving section and a reflecting section for reflecting light incident on the light receiving section and directing it to a light receiving element provided on the lower surface of the light receiving section. 5. The light guide according to claim 1, wherein the material is a resin transparent to infrared light, such as acrylic resin, ABS resin, or polycarbonate. 6. A plurality of light emitting elements and a light receiving element are arranged around the surface of the optical touch panel so as to face each other, and the light from the light emitting element to the light receiving element is shielded so as to detect the position or presence or absence of the object. In an optical position detecting device for detecting, the plurality of light emitting elements and light receiving elements, which are mounted in a frame shape around the surface of the optical touch panel and are arranged around the surface of the optical touch panel, are configured in a chip type. An optical position detecting device comprising: a substrate on which these are mounted in a planar shape; and the light guide according to claim 1, which is mounted on the substrate.