JPH0741273Y2 - Optical signal receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A. Industrial field of use B. Outline of the device C. Prior art D. Problems to be solved by the device E. Means for solving the problem F. Action G. Example [Fig. 1, Fig. 2 Fig.] H. Effect of the device (A. Field of industrial application) The present invention is an optical signal receiving device, and in particular, a signal processing integrated circuit and a photodetector surround at least a mounted circuit board and have a light receiving window and one side is open. The present invention relates to an optical signal receiving device in which the above-mentioned light receiver is mounted in the shield case so as to receive a signal from the outside through the light receiving window.

(B. Outline of the Invention) In the present invention, in the above-mentioned optical signal receiving device, in order to prevent crosstalk between the photoreceiver and the signal processing integrated circuit and enhance the receiving sensitivity, the photoreceiver is supported by a shield base. It is the one.

(C. Prior Art) Many devices such as television receivers and video tape recorders can be remotely controlled by a remote controller using infrared light. Such a device capable of remote control has a built-in optical signal receiving device for receiving a remote control signal by infrared light generated from a remote controller separate from the device body.

An optical signal receiving device of this type mounts a sensor (that is, a light receiver), a signal processing integrated circuit, and other necessary electric parts on a circuit board, as disclosed in Japanese Utility Model Laid-Open No. 62-11446. In general, a remote control signal receiving circuit is configured and the circuit board is mounted on a metallic module shield case having a light receiving window.

Further, such an optical signal receiving device is required to be small in size, low in price and high in performance as described in the above publication. This is because devices such as television receivers and video tape recorders that have a built-in optical signal receiver are required to be compact and have multiple functions, so an optical signal that only has the function of receiving a remote control signal. This is because it is not allowed for the receiving device to occupy a large space in a device such as a television receiver.

In addition, since the price reduction is required for the device incorporating the optical signal receiving device, the price reduction is naturally required. Further, the optical signal receiving device is required to have high performance so that it can be remotely controlled from a farther place.

(D. Problems to be solved by the device) By the way, since the light receiver receives weak infrared light and converts it into an electric signal, its output signal is also extremely weak. Therefore, the amplifier in the signal processing integrated circuit for processing the output signal of the light receiver has a very high gain, and the ratio of the signal level on the input side to the signal level on the output side becomes very large. Therefore, crosstalk should not occur between the input and output. However, there has been a problem that miniaturization of the optical signal receiving device brings about a high integration ratio of the circuit board and easily causes crosstalk.

In addition, it became necessary to use a small photoreceiver as the price of the optical signal receiving device decreased, but if the small photoreceiver was directly attached to the circuit board, the gap between the photoreceiver and the shield case would be large and open. There arises a problem that the receivable angle of the remote control signal of the optical signal receiving device becomes narrow and the sensitivity of the optical signal receiving device becomes low.

The present invention has been made to solve such a problem, and an object thereof is to prevent crosstalk between the photodetector and the signal processing integrated circuit and to enhance the receiving sensitivity.

(E. Means for Solving Problems) In order to solve the above problems, the optical signal receiving device of the present invention uses a positioning piece at a position where a photodetector is provided on the circuit board in the vicinity of the light receiving window of the shield case. A conductive shield base for positioning and supporting is attached in a state of being electrically connected to the ground wiring film, the shield base is made to support the light receiver, and the shield case is provided with a cap for closing the opening thereof. It is characterized by

(F. Operation) According to the optical signal receiving device of the present invention, since the shield and the signal processing integrated circuit can be electrostatically shielded by the shield base, crosstalk between them can be prevented.

The height of the light receiver can be adjusted to the height of the shield case by the shield table, and the receivable angle of the optical signal can be widened. Further, the position of the light receiver with respect to the light receiving window can be accurately positioned by the positioning piece of the shield base.

(G. Embodiment) [FIGS. 1 and 2] Hereinafter, an optical signal receiving device of the present invention will be described in detail with reference to illustrated embodiments.

The drawing shows one embodiment of the optical signal receiving device of the present invention. FIG. 1 is an exploded perspective view and FIG. 2 is a rear view of a circuit board.

In the drawing, reference numeral 1 is a circuit board, and wiring films 2i, 2i, ..., 2o, 2o, ..., 2e are formed on the back surface thereof as shown in FIG. , 2i, 2i, ... Are wiring films forming an input circuit of the remote control signal receiving circuit, 2o, 2o, ... Are wiring films forming an output circuit, and 2e is a ground wiring film. The ground wiring film 2e occupies the peripheral portion of the circuit board 1 and has a substantially 8-shaped pattern. One of the two regions surrounded by the 8-shaped ground wiring film 2e (first The wiring films 2i, 2i, ... Constituting the above-mentioned input circuit are formed in the left side region in FIG. 2), and the wiring films 2i, 2i, ... Forming the above input circuit are formed in the other region (the right side region in FIG. 2). The wiring films 2o, 2o, ... Which form the output circuit are formed. Reference numeral 3i indicates an area in which the components forming the input circuit are arranged, and 3o indicates an area in which the components forming the output circuit are arranged. Each electric component forming the input circuit and the output circuit is mounted on the front surface of the circuit board 1 except for the signal processing integrated circuit. Reference numeral 4 denotes an area on the back surface of the circuit board 1 where a signal processing integrated circuit (10) described later is arranged. The signal processing integrated circuit (10) is provided on the circuit board 1 in order to reduce crosstalk with a light receiver described later.
It is placed on the back side of the.

Reference numeral 5 denotes a shield table made of a conductive material, which supports the light receiver 6. Specifically, the shield base 5 has a substantially U-shaped front shape (a shape viewed from the lower left side in FIG. 1) and is oriented so that the intermediate piece is on the upper side. The upper surface 7 supports the light receiver 6. 8 and 8 are shield stands 5
Mounting leads formed on the lower end surface of one side edge of the one side of the circuit board 1 are inserted into the holes 9, 9 formed at one side edge portion of the circuit board 1, and the holes 9 and 9 are transferred to the back side. The protruding tip portion is soldered to the ground wiring film 2e.
As a result, the lower end surfaces of both side edges of the circuit board 1 are kept in a held state in close contact with the surface of the circuit board 1 and electrically grounded. Reference numeral 10 denotes a signal processing integrated circuit, which is attached to the area 4 on the back surface of the circuit board 1. Numerals 11, 11 and 11 are positioning pieces formed on the upper surface of the shield base 5 so as to project upward, and X of the light receiver 6 supported on the upper surface 7 of the shield base 5.
Positioning is performed in the (horizontal) direction, the Y (vertical) direction, and the θ (rotation) direction.

The light receiver 6 is a positioning piece 11, 11, 11 on the upper surface 7 of the shield base 5.
Is supported by the area surrounded by 12e, 12i
Is a lead. 12e is the anode lead that is grounded, 12i
Is a cathode lead, the anode lead 12e is inserted into a hole 13e formed near the side edge of the circuit board 1, and the cathode lead 12i is a hole inside the hole 13e.
Inserted in 13i, and lead 12e, hole 13e in 12i,
The tip portion protruding from 13i is connected to the ground wiring film 2e and one wiring film 2i by soldering. The holes 13e and 13i are separated from each other in a direction perpendicular to the side edge direction of the circuit board 1. This is because the light receiver 6 has tie bars on the leads 12e and 12i due to the production process and the forming process in the vicinity of the tie bar cannot be performed. Therefore, it is necessary to secure a necessary length for forming. The lead
This is because it is necessary to connect 12e to the ground wiring film e that occupies the peripheral portion of the back surface of the circuit board 1 and connect the other lead 12i to one wiring film 2i that forms the input circuit 3i.

Reference numeral 14 denotes a hemispherical condenser lens formed on the upper surface of the light receiver 6. It is not preferable to use a large photoreceiver because the cost of the optical signal receiving apparatus is low, and a small photoreceiver must be used. This substantially shortens the remote controllable distance of the remote controller and is not preferable. Therefore, the condensing lens 14 is provided so that the amount of received light can be made sufficiently large even if it is small.

Reference numeral 15 is a metal shield case having an opening on the lower surface, and a light receiving window 16 is formed on the upper surface. Into the shield case 15, the circuit board 1 on which the light receiver 6 supported by the shield base 5 and other electric parts 17, 17, ... Are mounted, is inserted upward from the opening and fixed by an appropriate means. It And
The shield case 15 and the ground wiring film 2e of the circuit board 1 are electrically connected by, for example, soldering.

The light receiver 6 supported by the shield base 5 and positioned by the positioning pieces 11, 11 and 11 is set at a position where the optical axis of the light receiving lens 14 thereof coincides with the central axis of the light receiving window 16, and from the outside. It is possible to more effectively receive the remote control signal by the infrared light.

Reference numeral 18 is a cap that closes the opening on the lower surface of the shield case 15.

According to such an optical signal receiving device, a signal processing integrated circuit
Since the circuit board 1 is disposed on the back surface of the circuit board 1 so that the circuit board 1 is interposed between the circuit board 1 and the light receiver 6,
Reduces the crosstalk between the signal processing integrated circuit 10 and the cathode of the light receiver 6. Moreover, since the light receiver 6 is supported by the shield base 5 which is grounded, the light receiver 6 and the signal processing integrated circuit are very effectively supported by the shield base 5.
Between 10 and 10 is electrostatically shielded and crosstalk can be prevented more completely.

Since the shield table 5 can increase the height of the light receiver 6 from the surface of the circuit board 1, a space is provided between the light receiver 6 and the light receiving window 16 of the shield case 15 even if the light receiver 6 is made very small. Can be placed in close proximity to each other. This leads to widening the receivable angle of the remote control signal, which is preferable. Then, it is preferable to match the optical axis of the light receiving lens 14 of the light receiving device 6 with the central axis of the light receiving window 16 in order to improve the light receiving efficiency.
Positioning of the shield with respect to the light receiving window 16
Since the positioning can be performed by 1, 11, and 11, the alignment accuracy can be made very high, and the light receiving efficiency can be made high.

(H. Effect of the Invention) As described above, the optical signal receiving device of the present invention has the shielded case in which the signal processing integrated circuit and the photodetector surround at least the mounted circuit board and have the light receiving window and one surface of which is open. In the optical signal receiving device in which the light receiver is mounted so as to be capable of receiving a signal from the outside through the light receiving window, the light receiver is provided on the circuit board in the vicinity of the light receiving window of the shield case. The conductive shield base, which is positioned and supported by the positioning piece at the position facing, is attached in a state in which it is electrically connected to the ground wiring film, the shield base is made to support the light receiver, and the shield case is provided with the above-mentioned structure. It is characterized in that a cap for closing the opening is provided.

Therefore, according to the optical signal receiving device of the present invention, since the shield and the signal processing integrated circuit can be electrostatically shielded by the shield base, crosstalk between them can be prevented.

The height of the light receiver can be adjusted to the height of the shield case by the shield table, and the receivable angle of the optical signal can be widened. Further, the position of the light receiver with respect to the light receiving window can be accurately positioned by the positioning piece of the shield table, and the light receiving efficiency can be improved.

[Brief description of drawings]

The drawing shows one embodiment of the optical signal receiving device of the present invention. FIG. 1 is an exploded perspective view and FIG. 2 is a rear view of a circuit board. Explanation of symbols 1 ... Circuit board, 2e ... Ground wiring film, 5 ... Shield base, 6 ... Photoreceiver, 10 ... Signal processing integrated circuit, 11 ... Positioning piece, 15 ... Shield case, 16 ... … Light receiving window, 18 caps.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04B 10/105 10/22 H04N 5/00 A H05K 1/02 P 9/00 C

Claims (1)

[Scope of utility model registration request] 1. A light receiving device is provided in a shield case having a light receiving window surrounding at least a circuit board on which a signal processing integrated circuit and a light receiving device are mounted and having an opening on one side, and the light receiving device receives light from the outside through the light receiving window. In an optical signal receiving device mounted so as to receive a signal, a conductive shield base for positioning and supporting the light receiver on the circuit board by a positioning piece at a position facing the light receiving window of the shield case. Is attached to the ground wiring film in a state of being electrically connected, the receiver is supported on the shield base, and the shield case is provided with a cap for closing the opening thereof. apparatus