JPH052036U - Light receiving module - Google Patents

Abstract

(57) [Summary] [Structure] A light receiving element provided with a lens portion having an inverted conical opening above the light receiving surface of the light receiving element is used.
The lens part of the photoreceptor is projected from the shield case,
A part having a light receiving element and a circuit element for detecting an output of the light receiving element are housed in a shield case. [Effect] As a result, an optical signal that is substantially perpendicular to the shield plane is introduced from the inverted conical opening of the lens section and guided to the light receiving element, and an optical signal coming from the lateral direction of the shield plane projects from the shield case. To the light receiving element after being reflected by the inverted conical portion, and such incident light is converted into an electric signal in the shield case and immediately processed by the circuit element.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a light receiving module including a light receiving element.

[0002]

[Prior Art]

 Conventionally, on the light receiving side when performing an optical remote control using infrared rays, as in Japanese Utility Model Laid-Open No. 1-202834, a light receiving element in which a light receiving element is resin-molded is covered with a shield case, and a through hole is formed in the shield case. I opened it and led an optical signal to the photo detector from there. Such a configuration has a certain directivity with respect to the incoming direction of the optical signal. That is, in a small television or the like, since the operator is in the direction in which the display tube is facing, the optical signal received from the direction of about 30 degrees to the left and right from the direction of the center of the display tube is received. I wish I could. The through hole provided in the shield case is provided in the flat part of the shield case and receives only the light that has passed through the through hole, so it is formed by inclining about 40 degrees about the perpendicular to the flat part of the shield case. It is sufficient to receive the light from the inside of the cone (directional region, which will be described again in the description of the embodiment).

[0003]

[Problems to be solved by the device]

 However, the size of the equipment has increased, and the number of cases in which equipment located near the ceiling, such as lighting equipment, has been operated by remote control has increased the need for wider directional angles. In other words, on a 29 to 40 inch television, the operator can enjoy the image anywhere in the room, and attach the lighting equipment hung from the ceiling and attach the remote control adapter to the outlet installed on the ceiling. When controlling lighting with, it is unknown whether the operator is at the entrance of the room or directly under the lighting fixture.

In these remote control devices, the cone described above requires an angle of approximately 90 degrees. In other words, it is necessary to receive an optical signal coming from a direction perpendicular to the shield plane and an optical signal coming directly from the side of the shield plane, and detect this with a low SN ratio.

[0005]

[Means for Solving the Problems]

 The present invention has been made in consideration of the above points, and uses as a light receiving element a lens element having an inverted conical opening above the light receiving surface of a light receiving element. The part projects from the shield case, and the part with the light receiving element and the circuit element for detecting the output of the light receiving element are housed in the shield case.

[0006]

[Action]

 As a result, an optical signal that is substantially perpendicular to the shield plane enters from the inverted conical opening of the lens section and is guided to the light receiving element, and an optical signal coming from the lateral direction of the shield plane comes from the side surface of the lens section that protrudes from the shield case. The light enters and is reflected by the inverted conical portion and guided to the light receiving element. Such incident light is converted into an electric signal in the shield case and immediately processed by the circuit element.

[0007]

【Example】

 FIG. 1 is a sectional view of a light receiving module showing an embodiment of the present invention, in which 1 is a light receiving body having a light receiving element 11 such as a phototransistor or a PIN photodiode, which is covered with a resin 12. A lens portion 13 having an inverted conical opening portion 131 is provided integrally with the resin 12 above the light receiving surface. Further, if necessary, the resin 12 and the lens portion 13 are mixed with a filter dye that transmits infrared light but attenuates visible light in accordance with the sensitivity characteristics of the light receiving element 11.

The photoreceptor 1 is fixed to a printed circuit board 21 or a lead frame and connected to a circuit element 3 that detects the output of the light receiving element 11. The circuit element 3 receives power from the outside or outputs a detection output. It is connected to the terminal 22.

Reference numeral 4 denotes a shield case for accommodating the printed circuit board 21, the circuit element 3 and the like, which has a substantially rectangular parallelepiped shape, and a through hole 41 is provided on one surface of the shield case. The lens portion 13 is projected from the shield case 4, and the portion of the resin 12 having the light receiving element 11 is housed in the shield case 4.

In such a configuration, since the lens portion above the light receiving surface of the light receiving element 11 is projected from the shield case 4, it will be easily understood that a wide range of optical signals can be received. The reception range varies depending on the shape of the lens. In (a) of FIG. 2, consider a line B inclined by θ degrees about the perpendicular A to the plane of the shield case 4 as an axis, and enclose this line B with a cone formed by rotating it about the perpendicular A. The area defined by this is called a cone, and the optical signal generator is placed in this cone. That is, the cone can be referred to as a directional region in the present invention. FIG. 3 shows the characteristics of θ and the received light output for the four lens shapes shown in FIG. 2 in order to investigate the size of the cone that can obtain the effective reception sensitivity. Although not shown, in the two lens shapes of (a) and (b), which have a high S / N ratio with respect to optical noise, the light receiving output in the lateral direction (θ> 60 degrees) is as shown in FIG. Low. It is shown that when the circular lens is completely projected from the shield case (C), the received light output has a large cone, but the level is low and the S / N ratio is poor.

The device (d) of the embodiment of the present invention has a relatively high level of received light output and S / N ratio. In particular, a high output when the cone θ is around 60 degrees is most suitable because it corresponds to an angle at a frequently used position in remote control control set on the ceiling. Thus, in the lens portion 13 having the inverted conical portion 132, the position of the light receiving element 11, that is, the distance d from the plane of the shield case 4 to the light receiving element 11 is related to the S / N ratio. Generally speaking, if the light receiving element 11 is covered with a shield case, it is about half the ratio of the size of the light receiving element 11 to the size of the through hole 41. For example, the through hole 41 has a diameter of 5 mm and the light receiving element 11 has one side. If the size is 2 mm, the distance d may be 1.25 mm or more. Specifically, the light emitting element and the light receiving element are arranged at the center of the cone (on the vertical line A), the lens portion of the light receiving element is projected into the shield case, and the light receiving element is separated by a distance of 1. When placed in a location of 5 mm and housed together with circuit elements, the optical noise when the visible light neon tube is placed in the cone is 95% of the distance at which the remote control signal can be detected without error. %, Which was 50% to 65% in terms of the ratio of no optical signal error with respect to electromagnetic noise when a flyback transformer was placed instead of the neon tube. These characteristics maintained substantially the same high S / N ratio even when the distance d was 2.0 mm. If the distance d of the light receiving element 11 is shortened or the circuit element 3 is provided on the outer wall of the shield case 4, it is less affected by optical noise but more susceptible to electromagnetic noise. The S / N ratio is significantly reduced to 20% at 0.5 mm and 10% at d of 0 mm (shield case plane position).

It is preferable that the angle of the above-mentioned inverted conical portion 132 is equal to or greater than the critical angle at which the light entering from the side is totally reflected. Further, it is more preferable to provide the convex lens 133 between the opening 131 of the inverted cone field and the light receiving element 11 because the light receiving output is further increased when the cone angle θ is in the range of 10 to 30 degrees and 75 degrees.

[0013]

[Effect of the device]

 As described above, an optical signal that is substantially perpendicular to the shield plane is introduced from the inverted conical opening of the lens section and guided to the light receiving element, and an optical signal coming from the lateral side of the shield plane is projected to the lens section protruding from the shield case. The incident light is reflected by the inverted conical portion and guided to the light receiving element. Such incident light is converted into an electric signal in the shield case and immediately processed by the circuit element, so that the S / N ratio is high, Moreover, the cone has a wide directivity of about 90 degrees, and can be used as a remote control receiver for ceilings and large equipment.

[Brief description of drawings]

FIG. 1 is a sectional view of a light receiving module of the present invention.

FIG. 2 is an explanatory diagram of a light receiving module in which a lens portion is projected from a shield case.

FIG. 3 is a directional sensitivity characteristic diagram of a light receiving module.

[Explanation of symbols]

 1 Photoreceptor 11 Photodetector 13 Opening 3 Circuit Element 4 Shield Case

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kunihiko Hirota, 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture, Tottori Sanyo Electric Co., Ltd. (72) Mikihito Yamane 3-201, Minamiyoshikata, Tottori City, Tottori Prefecture Sanyo Electric Co., Ltd.

Claims (1)

Claims for utility model registration: Claim 1. A light receiving body having a lens portion that covers the light receiving element and has an inverted conical opening above the light receiving surface of the light receiving element, and the lens portion of the light receiving element protrudes. A light-receiving module comprising a shield case that houses a part of the light-receiving element and a circuit element that detects the output of the light-receiving element.