JPH05259989A - Condensing filter and photodetecting element using the filter - Google Patents

Abstract

PURPOSE:To provide a highly precise photodetecting element which can improve the condensing efficiency by reducing the area of an emitting part compared with the area of an outer surface part and emitting concentrically the light beams obtained by emitting secondarily a large quantity of light beams condensed at the outer surface part. CONSTITUTION:A light emitter emits secondarily the light by a large quantity of visible or invisible light beams inputted from an outer surface part 12 of a condensing filter 10. Then the light emitted from the light emitter is repetitively reflected in a main body part 14 and transmitted to an emitting part 16 to be emitted to a photodetecting part 24 provided at the lower part through the part 16. The area of the emitting surface of the part 16 is smaller than the area of the part 12. Therefore the light beams emitted secondarily and transmitted are concentrically emitted from the part 16. Then these light beams are emitted to the part 24 of a photodetecting element 22 and this element 22 transmits a signal. Thus it is possible to obtain a highly precise photodetecting element which can improve the condensing efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensing filter and a light receiving element using the same.

[0002]

2. Description of the Related Art Conventionally, as signal transmission using visible light or invisible light, for example, there is a remote control device for electric equipment (television, etc.). In this remote control device, an infrared light emitting element is provided in a transmitter, and an infrared light receiving element is provided in an electric device which is a receiver. The transmitter is operated, the infrared light emitting element emits light, and infrared rays are radiated. When the light receiving section is irradiated with the infrared light, the infrared light receiving element generates a signal. Utilizing this property, the infrared light emitting element is driven by the modulated signal carrying the data, the light receiving element generates a signal corresponding to the modulated signal, and the data is transmitted to the electric device. The electric device controls the operation based on the transmitted data.

[0003]

However, the conventional signal transmission method using visible light or invisible light has the following problems. For example, in the case of not only an infrared light receiving element but also a light receiving element, the larger the amount of light received by the light receiving section, the larger the output and the more stable. Therefore, the larger the area of the light receiving portion, the higher the performance of the light receiving element. However, there is a problem in that the light receiving element including the light receiving portion is required to be micronized due to usage conditions and the area of the light receiving portion cannot be increased. There is also an economical problem that the light receiving element itself becomes expensive when the area of the light receiving portion is increased. Further, for example, in order to improve the sensitivity of the light receiving element, a special filter is used when it is desired to select and receive visible light or invisible light having a specific wavelength, but the amount of light received decreases because the filter is used. There is also the problem of being lost. Therefore, an object of the present invention is to provide a condensing filter capable of expanding the light receiving area and a light receiving element using the same.

[0004]

In order to solve the above problems, the present invention has the following constitution. That is, the condensing filter is formed on a flat surface or a curved surface, and an outer surface portion on which visible light or invisible light can be incident, and the specific wavelength when the visible light or the invisible light having a specific wavelength is irradiated. A main body formed of a material in which a luminous body that secondarily emits visible light or invisible light having the same wavelength as or different from that is mixed, and in which the visible light or invisible light that is secondarily emitted can be internally reflected and propagated; The visible light or the invisible light that is provided in the main body and reflected and propagated in the main body can be emitted, and the emission area of the visible light or the invisible light is smaller than the surface area of the outer surface portion. And a section. Further, in the body portion, a reflection portion for reflecting the visible light or the invisible light reflected and propagated to the end portion toward the emission portion may be provided at an end portion on the side opposite to the emission portion. Good. These condensing filters are provided integrally with or in close proximity to a light receiving element that outputs a signal when the light receiving section is irradiated with visible light or invisible light having a specific or unspecified wavelength, and the emitting section is provided with the light receiving section. It may be arranged so as to face each other.

[0005]

[Operation] The operation will be described. Since the emission area of the emission portion of the condensing filter is smaller than the surface area of the outer surface portion, a large amount of visible light or invisible light that is secondarily emitted by the visible light or invisible light that is concentrated on the outer surface with a large area. Can be concentrated and injected. These condensing filters are provided integrally with or close to the light receiving element that outputs a signal when the light receiving part is irradiated with visible light or invisible light having a specific or unspecified wavelength, and the emitting part of the condensing filter receives light. By facing the light receiving portion, a large amount of visible light or invisible light can be received even if the light receiving portion has a small area.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 (plan view) and FIG. 2 (front sectional view) show a light receiving device using the light collecting filter and the light receiving element of the first embodiment. In the figure, 10 is a condenser filter, which has a funnel shape in which the upper end surface is largely open and the lower end surface is small. The condensing filter 10 is formed of transparent synthetic resin (for example, acrylic resin or polycarbonate resin). The outer surface portion 12 (funnel-shaped outer peripheral surface and inner peripheral surface) of the condensing filter 10 can have a large condensing area and can condense light from all directions by adopting the illustrated shape. It is possible. From the outer surface portion 12, visible light or invisible light from the outside can enter the main body portion 14.

The synthetic resin forming the main body portion 14 (including the outer surface portion 12 and the emitting portion described later) of the light collecting filter 10 is irradiated with visible light or invisible light having a specific wavelength or a specific range of wavelength. A fine powder of a luminescent material that secondarily emits visible light or invisible light having a wavelength that is the same as or different from the wavelength of the specific range or the specific range is mixed (see, for example, JP-A-1-225986). By mixing the luminous body with the main body 14 of the condensing filter 10, the visible light or the invisible light emitted by the luminous body that has received the incident visible light or the invisible light is secondarily emitted and reflected in the main body 14. And can be propagated (see, for example, Japanese Patent Laid-Open No. 1-225986). Further, when the illuminant is irradiated with visible light or invisible light having the wavelength of the visible light or invisible light having the wavelength of the specific or specific range, it has the same or different wavelength as the wavelength of the specific or specific range. By making visible light or invisible light emit secondary light, it becomes possible to selectively detect only visible light or invisible light having the wavelength.

The lower end surface of the main body 14 of the condensing filter 10 is an emitting portion 16. The emitting unit 16 emits the visible light or the invisible light reflected and propagated in the main body 14 to the outside. The emitting area of the visible light or the invisible light of the emitting portion 16 is formed to be considerably smaller than the surface area of the outer surface portion 12. Reference numeral 18 is a reflecting portion, and the main body portion 1
4 is provided at the upper end portion on the opposite side of the injection portion 16. The reflection part 18 is formed in a ring shape, and the inner surface thereof is formed as a reflection surface (mirror surface). The reflector 18 is provided to reflect visible light or invisible light that has been reflected and propagated inside the main body 14 to the upper end in the direction of the emitting portion 16. By providing the reflecting portion 18, the amount of light emitted from the emitting portion 16 can be increased. Further, if the upper end surface of the main body portion 14 is formed at a right angle to the outer surface portion 12 and the reflecting portion 18 is provided thereon, the reflection propagation efficiency of light may be increased. As the reflecting portion 18, there are various methods such as a metal member having a flat mirror surface and a method of forming a mirror surface by depositing metal.

Reference numeral 22 denotes a light receiving element, which outputs a predetermined signal when the light receiving portion 24 formed on the upper surface is irradiated with visible light or invisible light having a specific (or unspecified) wavelength. .. The light receiving element 22 is a substrate fixed in the light receiving device main body (not shown) so that the light receiving section 24 approaches the emitting surface (lower end surface) which is the emitting section 16 of the condensing filter 10 and faces the emitting section 16. It is arranged on 26. In the light receiving device of the present embodiment, the light receiving element 22 is formed separately from the condensing filter 10 and arranged close to each other, but it may be integrally formed via a single housing.

The operation of the light receiving device having such a configuration will be described. Various light rays including invisible light rays are incident from the outer surface portion 12 of the condenser filter 10. A large amount of light rays that have entered the main body portion 14 from the wide outer surface portion 12 cause the light-emitting body to emit a large amount of secondary light, and the secondary light rays are emitted from the main body portion 1.
The light is repeatedly reflected within 4 and is propagated to the emission unit 16. On the other hand, the light ray propagated in the direction of the reflecting portion 18 is reflected by the reflecting portion 18 and is also propagated to the emitting portion 16. Injection part 1
The light beam propagated to 6 (secondary light beam) is emitted from the emission unit 16
The light is emitted downward from the lower end surface (emission surface) toward the light receiving portion 24. At that time, since the area of the exit surface of the exit section 16 is formed to be considerably smaller than the area of the outer surface section 12, the secondary emitted and propagated light rays are concentrated and exit from the exit section 16. To be done. The light beam intensively emitted from the emission unit 16 is applied to the light receiving unit 24 of the light receiving element 22. When the light receiving unit 24 receives light, the light receiving element 22 emits a signal.
The light receiving device receives the modulated optical signal carrying the data, causes the light receiving element 22 to generate a signal corresponding to the modulated signal, and demodulates the data. The demodulated data is used for controlling devices and devices connected to the subsequent stage of the light receiving device.

Next, a second embodiment will be described with reference to FIG. 3 (plan view) and FIG. 4 (partially cutaway front view). The same members as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. The condensing filter 10 of FIGS. 3 and 4 is formed in a hollow cylindrical shape. Therefore, the light receiving direction is approximately the outer peripheral surface (outer surface portion 12) of the light collecting filter 10.
Is the direction that is facing. Therefore, when the inner peripheral surface of the condensing filter 10 does not have a function as the outer surface portion, the reflecting portion 18 may have a simple circular shape instead of the ring shape. Compared with the condensing filter 10 of the first embodiment, the condensing filter 10 of the second embodiment has a smaller condensing area but can occupy a smaller volume, so that the miniaturization of the light receiving device can be further promoted. There is an advantage.

Next, a third embodiment will be described with reference to FIG. 5 (plan view) and FIG. 6 (partially cutaway front view). The same members as those in the first and second embodiments are designated by the same reference numerals as those in the first and second embodiments, and the description thereof will be omitted. Figure 5
The condenser filter 10 shown in FIG. 6 is formed in the shape of a single shaft. Therefore, the light receiving direction is the direction in which the outer peripheral surface (outer surface portion 12) of the condensing filter 10 faces. Therefore, the reflecting portion 18 is formed in a simple circle, not in a ring shape. Compared with the condensing filter 10 of the first embodiment, the condensing filter 10 of the third embodiment also has a smaller condensing area but can occupy a smaller volume, so that the light receiving device can be further downsized. There is an advantage of becoming. The most characteristic feature of the third embodiment is the condensing filter 10.
The point is that the light receiving element 22 is integrally insert-molded therein. Therefore, the portion of the body portion 14 that is in surface contact with the upper surface of the light receiving portion 24 becomes the emitting portion 16.

Although the reflecting portion 18 is provided in each of the above-described embodiments, the reflecting portion 18 is optional so as to enable efficient reflection and propagation of light rays in the body 14 as well as in the upper end surface of the condenser filter 10. It can be used by appropriately attaching it to the position of, or by integrally forming with the main body portion 14. Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and, for example, the outer surface portion 1
2 may be a flat surface or a spherical curved surface, or the condensing filter 10
Any shape and size can be adopted depending on various conditions such as a mounting position and a light collecting direction, and the application range is not limited to the light receiving device having the light receiving element 22. Of course, modifications can be made.

[0014]

When the light collecting filter according to the present invention is used,
Since the emission area of the emission portion of the condensing filter is smaller than the surface area of the outer surface portion, a large amount of visible light or invisible light that is secondarily emitted by the visible light or invisible light that is concentrated on the outer surface with a large area. Since the light can be concentrated and emitted, efficient light collection is possible. In particular, by providing the reflecting portion, visible light or invisible light propagated in the direction opposite to the emitting portion can be reflected and propagated in the emitting portion direction, so that the light collection efficiency can be further improved. Becomes These condensing filters are provided integrally with or close to the light receiving element that outputs a signal when the light receiving part is irradiated with visible light or invisible light having a specific or unspecified wavelength, and the emitting part of the condensing filter receives light. By facing the light receiving portion, a large amount of visible light or invisible light can be received even if the area of the light receiving portion is small, so that a highly accurate light receiving element can be provided, and so on.

[Brief description of drawings]

FIG. 1 is a plan view of a light receiving device of a first embodiment using a light collecting filter and a light receiving element according to the present invention.

FIG. 2 is a front sectional view of the light receiving device of the first embodiment.

FIG. 3 is a plan view of a light receiving device according to a second embodiment.

FIG. 4 is a partially cutaway front view of a light receiving device according to a second embodiment.

FIG. 5 is a plan view of a light receiving device according to a third embodiment.

FIG. 6 is a partially cutaway front view of a light receiving device according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Condensing filter 12 Outer surface part 14 Main body part 16 Ejecting part 18 Reflecting part 22 Light receiving element 24 Light receiving part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H04Q 9/00 371 Z 7170-5K

Claims (3)

[Claims] 1. An outer surface portion which is formed on a flat surface or a curved surface and on which visible light or invisible light can be incident, and has the same specific wavelength when irradiated to the visible light or invisible light having a specific wavelength. Alternatively, a main body formed of a material in which a luminous body that secondarily emits visible light or invisible light having different wavelengths is mixed, and the secondarily emitted visible light or invisible light can be internally reflected and propagated; The visible light or the invisible light that has been propagated by being reflected in the main body while being provided in the portion, and is capable of emitting, and the emission area of the visible light or the invisible light is smaller than the surface area of the outer surface portion. A condensing filter comprising: 2. A reflection portion for reflecting the visible light ray or the invisible light ray reflected and propagated to the end portion toward an emission portion at an end portion on a side opposite to the emission portion in the main body portion. The condensing filter according to claim 1, wherein the condensing filter is provided. 3. A light-receiving element that outputs a signal when the light-receiving portion is irradiated with visible light or invisible light having a specific or unspecified wavelength, wherein the emitting part of the condensing filter according to claim 1 or 2. A light-receiving element arranged so as to face the light-receiving section.