JP2003304206A - Light guide for infrared signal, infrared receiver and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high performance light guide capable of effectively guiding an infrared signal to a receiver and an infrared receiver having a wide distance range and a wide angle range in receiving infrared signals. <P>SOLUTION: The attenuation of infrared rays due to absorption is reduced by forming the light guide as a hollow cylinder whose one end is closed. The outgoing end face of the light guide is formed as a recessed face to make outgoing infrared rays parallel as far as possible to a side face. The outer surface of the light guide and the infrared receiver are covered with a metallic film to shield electromagnetic waves from the outside. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide for guiding an infrared signal to an infrared receiving device, an infrared receiving device, and electronic equipment equipped with these.

[0002]

2. Description of the Related Art In recent years, many electronic devices have been controlled by remote control, and control signals are generally transmitted by infrared rays. In such an electronic device, a light receiving window is usually provided in the housing, and a receiving device for receiving an infrared signal is arranged in the housing in the vicinity of the light receiving window.
However, due to the presence of other components and restrictions such as design, it may not be possible to place the infrared receiver near the light receiving window.In such a case, place the infrared receiver away from the light receiving window. A light guide is arranged between the light receiving window and the receiving device so that an infrared signal is guided to the receiving device by the light guide.

The light guide is made of resin or glass, and has a columnar shape with flat ends at both ends and no voids inside. A vertical section of a conventional light guide 99 is shown in FIG. The infrared rays that have entered the light guide 99 from one end reach the other end after being reflected directly or on the side surface and enter the light receiving portion of the infrared receiver.

The infrared receiver detects a signal by photoelectric conversion and amplifies the detected signal, but its processing is easily affected by electromagnetic waves emitted from surrounding electronic components. For this reason,
Store the infrared receiver in a metal shield case,
We are trying to reduce noise. In addition, if the angle range that can receive infrared signals is high and directivity is narrow, there will be a large restriction on remote control.
The infrared receiver has a light-collecting function.

[0005]

As the material of the light guide, resin or glass, which has a high transparency to infrared rays, is used, but since infrared rays are still absorbed to some extent, infrared signals pass through the inside of the light guide. Decays while doing. Infrared signal attenuation leads to a reduction in the range of distances over which electronic equipment can be operated remotely.

Further, since the optical path of the infrared light emitted from the light guide is parallel to the optical path before entering the light guide regardless of whether it is reflected by the side surface of the light guide, the light guide receives the infrared light. It does not have the ability to extend the angular range over which the device can receive infrared signals. Infrared rays that enter the light guide from an oblique direction travel inside the light guide while being reflected by the side surfaces, but are totally reflected when the angle of incidence on the side surfaces becomes smaller (close to vertical) and becomes less than the critical angle. It disappears and a part leaks. This leads to a narrow angular range in which infrared signals can be received.

The light guide and the infrared receiving device are manufactured as separate parts, and when equipped in an electronic device, it is necessary to align the light guide and the light receiving portion of the receiving device. Moreover, the cost of the electronic device including the light guide and the infrared receiving device, which are separate components, becomes high.

The present invention has been made in view of these problems, and has a high-performance light guide capable of favorably guiding an infrared signal to a receiving device and an infrared ray having a wide range of distances and angles capable of receiving an infrared signal. An object is to provide a receiving device and an electronic device.

[0009]

In order to achieve the above object, in the present invention, the light guide for guiding the infrared signal to the infrared receiving device has a hollow columnar shape with one end closed. In this light guide, the hollow portion, that is, air, can be used as a passage of infrared rays, and the attenuation of infrared rays due to absorption can be suppressed. Because one end is closed,
By arranging this end portion toward the outside, invasion of foreign matter such as dust or dust can be avoided.

Further, according to the present invention, the light guide for guiding the infrared signal to the infrared receiver has a columnar shape with one end concave. Since the concave surface has a negative power with respect to the infrared rays emitted from the inside, the infrared rays reflected by the side surface can be made into a light ray having a small angle with respect to the side surface. Therefore, by arranging this end face toward the infrared receiving device, the incident angle of the infrared ray with respect to the infrared receiving device becomes small, the angle range in which the infrared signal can be received is smaller than the angle range in which the infrared receiving device can receive alone. Get wider

Further, according to the present invention, the light guide for guiding the infrared signal to the infrared receiver has a columnar shape and the side surface is covered with metal. Even when the infrared receiving device is housed in the shield case, the light receiving portion facing the light guide is exposed, so that electromagnetic waves in the surrounding area easily enter the light receiving portion from an oblique direction. By covering the side surface of the light guide with metal, it is possible to significantly block the electromagnetic waves that obliquely enter the light receiving portion. Moreover, since the metal functions as a reflection film, even when the infrared rays traveling inside enter the side surface at an incident angle less than the critical angle, they can be reflected and prevented from leaking, and a decrease in light quantity can be avoided. .

It is preferable that each of the light guides described above has an accommodating portion for accommodating at least a part of the infrared receiver at one end. This makes it possible to handle the infrared receiving device and the light guide as one component, and the infrared receiving device is also protected.

In this case, it is preferable that the accommodating portion has a protrusion for alignment with the infrared receiver. The position of the infrared receiving device with respect to the light guide is determined, and the infrared light guided by the light guide can be accurately incident on the infrared receiving device.

In the structure in which the side surface of the column is covered with the metal, the metal is preferably continuous from the side surface to the housing portion, and the outer surface of the housing portion is also covered with the metal. With this configuration, it is possible to block the electromagnetic wave with the metal that covers the housing portion, and it is not necessary to house the infrared receiver in the shield case.

Further, the accommodating portion may be provided with a protrusion for providing solder for connecting the metal covering the outer surface and the ground terminal of the infrared receiver. It is possible to realize, with a simple configuration, to prevent the metal from being charged and maintain the function of blocking electromagnetic waves.

Further, in the present invention, the infrared receiving device for receiving the infrared signal is formed integrally with a columnar light guide for guiding the infrared signal to itself, and is covered with metal along with the side surface of the light guide. By integrating the infrared receiving device with the light guide, handling is easy, and by covering with a metal, electromagnetic waves can be blocked without housing in a shield case. By covering the side surface of the light guide with a metal, it is possible to block electromagnetic waves that are obliquely incident on the light receiving portion. A decrease in the amount of light due to the leakage of infrared rays from the side surface of the light guide is also prevented.

Here, it is preferable to have a structure having a supporting portion so that the supporting portion can stand by itself. The mounting on the device becomes easy, and the accuracy of the arrangement position in the device can be improved.

Further, according to the present invention, an electronic device for receiving an infrared signal includes an infrared receiving device and any one of the above light guides, or any one of the above infrared receiving devices. Due to the structural features of the light guide, the electronic device has a wide range of distances and a wide range of angles that can receive infrared signals. The cost can also be reduced by forming the infrared receiving device integrally with the light guide.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a vertical cross section of the light guide 1 of the first embodiment. The light guide 1 is made of a resin having a high transmittance for infrared rays and has a cylindrical outer shape. Inside 11 of the light guide 1
Has a cylindrical hollow shape, and the hollow portion 11 communicates from one end to the outside and the other end is closed. The light guide 1 is used in such an arrangement that its open end faces the infrared receiving device and its closed end faces the outside, and guides the infrared signal sent from the external signal source to the infrared receiving device.

Most of the infrared rays incident from the closed end are
As it passes through the hollow portion 11, it reaches the infrared receiver without being absorbed by the resin material. A case where the light guide 1 has a hollow portion 11 and a case where FIG.
Table 1 shows the amount of infrared light received by the infrared receiver in the case where the conventional light guide 99 has no hollow portion. The incident angles shown in the table are incident angles with respect to the closed end portion, and the infrared rays are incident vertically here. In addition, in each configuration, the conditions such as the material, the outer shape, the size, and the infrared emission amount are the same except for the presence or absence of the hollow portion. It can be seen from Table 1 that the amount of received light is increased several times by providing the hollow portion 11.

[0021]

[Table 1]

Table 2 shows the amount of infrared light received by the infrared receiver when the inner diameter of the hollow portion 11 is equal to or larger than the diameter of the condenser lens of the infrared receiver and is smaller than the diameter. It is preferable that the inner diameter of the hollow portion 11 is equal to or larger than the diameter of the condenser lens so that the entire condenser lens faces the hollow portion 11.
It can be seen that the amount of light received increases.

[0023]

[Table 2]

FIG. 2 shows a vertical cross section of the light guide 2 of the second embodiment. This light guide 2 is obtained by modifying the light guide 1 of the first embodiment so that the open end portion thereof has a spherical concave surface 12. A part of the infrared rays incident from the closed end travels in the side wall surrounding the hollow portion 11, and the concave surface 12
It emits more and reaches the infrared receiver. The concave surface 12 has a negative power with respect to the emitted infrared rays,
The infrared rays reflected by the side surface are brought closer to the outer surface side of the side wall while traveling in the side wall. For this reason, even when the incident angle of infrared rays on the closed end is large, the incident angle of infrared rays on the infrared receiver becomes small. Therefore, the angle range in which the infrared signal can be received is widened, and the receivable distance when the infrared signal is given from an oblique direction also becomes long.

Table 3 shows the relationship between the radius of curvature R of the concave surface 12 and the amount of infrared light received by the infrared receiver. From Table 3,
It can be seen that by making the end face from which infrared rays are emitted the concave surface 12, a sharp decrease in the amount of received light when an infrared signal is given from a direction that is largely inclined is reduced. It should be noted that making the end face from which infrared rays are emitted concave is also effective in a configuration having no hollow portion 11.

[0026]

[Table 3]

FIG. 3 shows a vertical cross section of the light guide 3 of the third embodiment. This is a modification of the light guide 1 of the first embodiment so that the accommodating portion 13 for accommodating a part or the whole of the infrared receiver is provided continuously to the open end, and the outer surface of the side wall of the hollow portion 11 and Side wall 1 of accommodating portion 13
The outer surface of 3a is covered with a metal film 14. Metal film 1
4 can be formed by vapor deposition of aluminum, for example.

By providing the accommodating portion 13 and accommodating the infrared receiving device therein, it becomes possible to handle the infrared receiving device and the light guide as one component. Further, by covering the side wall 13a of the housing portion 13 with the metal film 14, it is possible to block electromagnetic waves entering the infrared receiving device from the outside with the metal film 14, and it is not necessary to house the infrared receiving device in the shield case. . Further, since the side wall of the hollow portion 11 is also covered with the metal film 14, it is possible to block an electromagnetic wave that obliquely enters the light receiving portion of the infrared receiving device facing the hollow portion 11, and noise caused by the electromagnetic wave can be blocked. Can be further suppressed.

Further, the metal film 14 can reflect light traveling inside the side wall of the hollow portion 11, and can prevent leakage of infrared rays incident on the outer surface of the side wall at an angle less than the critical angle. For this reason, the angular range in which the infrared signal can be received is widened, and the receivable distance when the infrared signal is given from an oblique direction also becomes long.

FIG. 4 shows a longitudinal section of the light guide 4 and the infrared receiver 9 of the fourth embodiment. The light guide 4 is formed integrally with the infrared light receiving device 9, and the outer surface of the side wall of the hollow portion 11 and the surface of the infrared light receiving device 9 are covered with a metal film 14. Integrating the light guide 4 and the infrared light receiving device 9 facilitates handling, and in particular, the light guide 4 and the infrared light receiving device 9 when mounted on an electronic device.
The alignment of is unnecessary. No need for a shield case, capable of blocking electromagnetic waves that obliquely enter the light receiving part,
Also, leakage of infrared rays from the side wall of the hollow portion 11 is prevented, as in the third embodiment. The infrared receiver 9 is in contact with the open end of the light guide 4, and the infrared rays guided by the light guide 4 all enter the light receiver of the infrared receiver 9. Further, the infrared receiver 9 is provided with a ground terminal 9a for grounding.

FIG. 5 shows a vertical cross section of the light guide 5 and the infrared receiver 9 of the fifth embodiment. This is a modification of the fourth embodiment, and the support 1 for supporting the infrared receiver 9 is provided.
5 is added. The support 15 is made of metal and is continuous with the metal film 14. When the support section 15 is placed on a horizontal plane with the support section 15 facing downward, the integrated light guide 5 and the infrared receiver 9 stand by themselves. In this way, the self-sustaining structure facilitates mounting on an electronic device.

The infrared receiving device 9 is provided with the ground terminal 9a and the support portion 15 is also provided with the ground terminal 16, so that the support portion 15 and the metal film 14 are grounded and are not charged. Therefore, the electromagnetic wave can be reliably blocked by the metal film 14.

FIG. 6 shows a vertical cross section of the light guide 6 and the infrared receiver 9 of the sixth embodiment. This is a modification of the third embodiment, in which the light guide 6 and the infrared receiver 9 housed in the housing 13 are integrated, and the solder 17
The metal film 14 is connected to the ground terminal 9a of the infrared receiver 9 by means of. A protrusion 13b is provided on the side wall 13a of the housing 13 near the ground terminal 9a in order to facilitate the attachment of the solder 17.

The infrared light receiving device 9 is separated from the light guide 6. However, a lens 9b for condensing light is provided immediately before the light receiving portion of the infrared light receiving device 9, and almost all the infrared rays guided by the light guide 6 are incident on the light receiving portion.

FIG. 7 shows a vertical cross section of the light guide 7 and the infrared receiver 9 of the seventh embodiment. This is because the hollow portion 11 is formed when the light guide 7 and the infrared receiver 9 are integrated.
And a protrusion 18 that defines the relative position of the light receiving portion of the infrared receiver 9 is provided on the upper wall 13c of the housing portion 13. A hole that engages with the protrusion 18 is provided on the upper surface of the infrared receiver 9. The light guide 7 and the infrared receiver 9 are
The protrusions 18 are fixed in place by the adhesive 19 while being inserted into the holes.

For example, when the light guide has a cylindrical shape with a diameter of 4.4 mm, and the center line of the light guide is deviated by 1 mm from the center of the light receiving portion of the infrared receiving device, the amount of infrared rays entering the light receiving portion of the infrared receiving device is 20. % Decrease. By providing the protrusion 18 and accurately defining the relative position between the light guide 7 and the infrared receiver 9 as in the present embodiment, such a decrease in the amount of received light can be prevented.

The light guide and infrared receiving device shown in each of the above embodiments can be provided in various electronic devices for receiving infrared signals, such as VTRs, audio components, air conditioners and the like. FIG. 8 shows a vertical cross section of the television of the eighth embodiment, which is an example thereof. Case 1 of TV 10
A light receiving window is provided in the lower part of the front surface of 0a, and the infrared receiving device 9 receives an infrared signal given through the light receiving window. However, since the other component X is arranged around the light receiving window, the infrared receiving device 9 cannot be arranged near the light receiving window. Therefore, the infrared receiving device 9 is arranged at a position away from the light receiving window, and the light guide 1 of the first embodiment is arranged between the light receiving window and the infrared receiving device 9 so that the infrared light incident from the light receiving window is emitted. The light guide 1 guides the light to the infrared receiver 9.

Although the example in which the light guide 1 of the first embodiment is adopted is given here, it goes without saying that the light guides 2 to 7 of the second to seventh embodiments may be adopted. .

[0039]

When the light guide for guiding the infrared signal to the infrared receiving device has a hollow columnar shape with one end closed as in the present invention, the attenuation of infrared rays due to absorption can be suppressed, and the infrared signal can be suppressed. The distance that can be received becomes longer.

When the light guide for guiding the infrared signal to the infrared receiving device has a columnar shape with one end concave as in the present invention, the infrared receiving device is arranged by arranging the concave end face toward the infrared receiving device. The angle of incidence of infrared rays on the infrared ray becomes smaller, and the angle range in which infrared rays can be received can be made wider than the angle range in which the infrared receiving device can independently receive.

If the light guide for guiding the infrared signal to the infrared receiving device has a columnar shape and the side surface is covered with metal as in the present invention, electromagnetic waves entering the light receiving portion of the infrared receiving device can be blocked. It is possible to suppress the generation of noise. Moreover, since the metal functions as a reflection film, even when the infrared rays traveling inside enter the side surface at an incident angle less than the critical angle, leakage can be prevented, and a decrease in light amount can be prevented. Therefore, the range of distance in which the infrared signal can be received becomes longer and the range of angle becomes wider.

If the housing having at least one part of the infrared receiver is housed at one end, the infrared receiver and the light guide can be handled as one component, and the infrared receiver is also protected.

Here, if the accommodating portion has a protrusion for alignment with the infrared receiving device, the position of the infrared receiving device with respect to the light guide is determined, and the infrared light guided by the light guide is accurately received. Can be incident on.

In the structure in which the side surface of the column is covered with metal,
If the metal extends from the side surface to the housing and the outer surface of the housing is also covered with the metal, electromagnetic waves can be blocked by the metal covering the housing, and the infrared receiver is housed in the shield case. No need. Therefore, the structure is simple and the cost can be suppressed.

By providing the housing with a protrusion for providing a solder for connecting the metal covering the outer surface and the ground terminal of the infrared receiver, the function of preventing the metal from being charged and maintaining the electromagnetic wave can be maintained. Can be realized with a simple configuration.

An infrared receiving device for receiving an infrared signal,
As in the present invention, if the columnar light guide that guides the infrared signal to the self is formed integrally and is covered with the metal along with the side surface of the light guide, the integration facilitates the handling, and the shield case. Without storing it in
Electromagnetic waves can be blocked, resulting in low cost. A decrease in the amount of light due to the leakage of infrared rays from the side surface of the light guide is also prevented, and the range of distance and the range of angles at which infrared signals can be received are widened.

In particular, if the support section is provided so that the support section can stand on its own, it becomes easy to mount the apparatus on the apparatus and the accuracy of the arrangement position in the apparatus can be improved.

When an electronic device for receiving an infrared signal is provided with the infrared receiving device and the light guide according to any one of the present invention, or the infrared receiving device according to the present invention, the characteristics of the light guide are utilized, The electronic device has a wide range of distances and a wide range of angles that can receive infrared signals. The cost can also be reduced by providing the infrared receiver integrally formed with the light guide.

[Brief description of drawings]

FIG. 1 is a vertical sectional view schematically showing the configuration of a light guide according to a first embodiment.

FIG. 2 is a vertical sectional view schematically showing the configuration of a light guide according to a second embodiment.

FIG. 3 is a vertical sectional view schematically showing the configuration of a light guide according to a third embodiment.

FIG. 4 is a vertical cross-sectional view schematically showing the configurations of a light guide and an infrared receiver according to a fourth embodiment.

FIG. 5 is a vertical cross-sectional view schematically showing the configurations of a light guide and an infrared receiving device according to a fifth embodiment.

FIG. 6 is a vertical sectional view schematically showing the configurations of a light guide and an infrared receiving device according to a sixth embodiment.

FIG. 7 is a vertical sectional view schematically showing the configurations of a light guide and an infrared receiving device according to a seventh embodiment.

FIG. 8 is a vertical cross-sectional view that schematically shows the configuration of the television of the eighth embodiment.

FIG. 9 is a vertical cross-sectional view schematically showing the configuration of a conventional light guide.

[Explanation of symbols]

1-7 Light guide 9 Infrared receiver 9a ground terminal 9b Condensing lens 11 Hollow part 12 concave 13 accommodation 13a Housing side wall 13b protrusion 13c Housing upper wall 14 Metal film 15 Support 16 ground terminals 17 Solder 18 protrusions 19 adhesive 10 TV 10a housing

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04B 10/135 10/14 10/18

Claims (10)

[Claims] 1. A light guide for guiding an infrared signal to an infrared receiver, which is a hollow column having one end closed. 2. A light guide for guiding an infrared signal to an infrared receiving device, wherein the light guide is a column having a concave surface at one end. 3. A light guide for guiding an infrared signal to an infrared receiver, the light guide being columnar and having a side surface covered with a metal. 4. The light guide according to claim 1, further comprising an accommodating portion for accommodating at least a part of the infrared receiving device at one end. 5. The light guide according to claim 4, wherein the accommodating portion has a protrusion for alignment with the infrared receiver. 6. The light guide according to claim 4, wherein the outer surface of the housing portion is covered with a metal extending from the side surface. 7. The light guide according to claim 6, wherein the accommodating portion has a protrusion for providing a solder for connecting the metal covering the outer surface and the ground terminal of the infrared receiver. 8. An infrared receiving device for receiving an infrared signal, wherein the infrared receiving device is integrally formed with a columnar light guide for guiding the infrared signal to itself, and is covered with a metal together with a side surface of the light guide. Infrared receiver. 9. The infrared receiver according to claim 8, wherein the infrared receiver has a supporting portion and can stand on its own. 10. An electronic device for receiving an infrared signal, the infrared receiving device and the light guide according to any one of claims 1 to 7, or the light guide according to claim 8 or 9. An electronic device comprising an infrared receiver.