JPH10145121A - Receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high antenna gain in a space decided by fitting a shielding case through covering various electric parts on a circuit board and fitting an antenna on the parts along an antenna holder by detaching the antenna from the parts. SOLUTION: A shielding case 12 is fitted so that it covers various electric parts 15, arranged on a circuit board 11 and it is grounded. Thus, the high-frequency electromagnetic wave noise which is generated from various electronic parts 15, is reduced and radio interruption is reduced. Furthermore, the shielding case 12 improves the gain of an antenna 6 by means of Miller effect as the base board of the antenna 6. The antenna 6 is fitted along a guide groove 20, and a supporting groove 21 of the antenna holder 13 arranged along the inner peripheral face of the storage recessed part 14a in a storage case 14 and is wired. Thus, the antenna 6 is detached from the circuit board 11 and is securely supported and fixed. It can easily receive transmitted radio waves and receives the effect of the base board of the shielding case 12 to the utmost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver.

[0002]

2. Description of the Related Art In recent years, a remote control device (remote control device) called a "keyless entry system" has been widely used in automobiles. In the keyless entry system, radio waves are emitted from a transmitter built into the grip part and key holder part of the ignition key, and the radio waves are received by the on-board receiver, so that door locks and engine starting etc. can be performed even from a distance from the car. It is possible to control.

[0003]

The above-mentioned receiver is naturally required to have high reception sensitivity. In order to improve the receiving sensitivity, it is necessary to increase the size of the antenna built in the receiver to improve the antenna gain. However, on the other hand, downsizing of the receiver is required. That is,
The space for configuring the antenna is limited, and the size cannot be simply increased to improve the antenna gain. That is, miniaturization of the receiver and improvement of the antenna gain are contradictory, and it is difficult to achieve both.

[0004] The present invention has been made to solve the above problems, and an object of the present invention is to provide a receiver capable of obtaining a high antenna gain in a predetermined space.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a housing case in which a housing recess is formed for housing various electronic components, An antenna that receives radio waves from the machine,
A receiving circuit formed of the various electronic components mounted on a circuit board fitted in the opening of the housing case and receiving a signal from the antenna, the receiver comprising: A grounded conductive shield member is mounted on the circuit board so as to cover the components, and the antenna stands from a connection point with a receiving circuit in a direction to separate the shield member from the board on which the shield member is mounted. Raise it,
The gist is that wiring is carried out along the inner peripheral surface of the accommodation recess.

According to a second aspect of the present invention, in the receiver according to the first aspect, the antenna is wired so as not to fall after rising from a connection point with the receiving circuit. And

[0007] The invention described in claim 3 is the first or second invention.
Wherein the antenna is wired along a support member attached to the circuit board.

Accordingly, according to the first aspect of the present invention,
A conductive shield member, which is grounded so as to cover various electronic components, is mounted on the circuit board, and the antenna rises from a connection point with a receiving circuit so as to be separated from the board on which the shield member is mounted. Are wired along the inner peripheral surface. Therefore, the antenna can have a longer overall length, can easily receive the transmitted radio wave, can effectively receive the effect of the ground plate of the shield member grounded, and can obtain a high antenna gain.

According to the second aspect of the present invention, the antenna is wired so as not to fall after rising from the connection point with the receiving circuit. As a result, a high antenna gain is reliably obtained.

According to the third aspect of the present invention, the antenna is securely supported by the support member attached to the circuit board.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 3 shows an electrical configuration of a remote control device 1 for remotely locking and unlocking a door (not shown) of an automobile. An operation switch 3 is provided on the portable transmitter 2. Transmitter 2
Reads out an identification code stored in advance in a memory (not shown) based on the operation of the operation switch 3, modulates the identification code, and then transmits the modulated identification code to an instrument panel (hereinafter simply referred to as an instrument panel) of the vehicle. ) Is transmitted to the receiver 4 accommodated in the receiver.

The receiving circuit 5 of the receiver 4 includes an antenna 6
Receiving the identification code transmitted from the transmitter 2 via
The received identification code is demodulated and shaped, that is, digitized, and output to the processing circuit 7.

The processing circuit 7 is provided with a memory (not shown) therein, and stores a discrimination code in advance. When the identification code is input from the receiving circuit 5, the processing circuit 7 reads the identification code stored in the memory, and compares the identification code with the identification code. Then, the processing circuit 7 outputs a drive signal to the actuator 8 provided in the vehicle only when the two codes match. The actuator 8 is driven based on a drive signal from the processing circuit 7, and the drive locks or unlocks each door of the automobile.

Next, the configuration of the receiver 4 provided in the instrument panel will be described. 1 and 2 show the receiver 4. The receiver 4 includes an antenna 6, a circuit board 11 that forms the receiving circuit 5, a shield case 12 as a conductive shield member, an antenna holder 13 made of a synthetic resin as a support member, a housing case 14 made of a synthetic resin, and the like. Have been. The housing case 14 has a housing recess 1 in which the antenna 6 and the antenna holder 13 are housed.
4a are formed, and the circuit board 11 is fitted into the opening 14b. Incidentally, the housing case 14 is formed with a size large enough to house the antenna 6, the antenna holder 13 and the like in the housing recess 14a. In the present embodiment, both the vertical and horizontal lengths are 8 cm and the height is It is formed in 4 cm.

A conductor wiring pattern (not shown) is formed on the front surface 11a of the circuit board 11, and various electronic components 15 such as an IC chip, a chip resistor, and a chip capacitor which constitute the receiving circuit 5 are formed on the conductor wiring pattern. Is soldered. Various electronic components 15 are connected to a connector 16 mounted on the front surface 11a via a conductor wiring pattern. The receiving circuit 5 is connected to the processing circuit 7 via a connector 16.

A shield case 12 made of a conductive material is attached to the circuit board 11 so as to cover various electronic components 15. The shield case 12 is connected to a ground terminal of the connector 16 via a conductor wiring pattern and is grounded. The grounded shield case 12 reduces high-frequency electromagnetic noise generated from the various electronic components 15 and reduces radio interference caused by the electromagnetic noise.

At the end of the circuit board 11, an insertion hole 17 through which the antenna 6 is inserted is formed. Antenna 6
Is a conductive wire of, for example, iron, copper, or the like, the base end 6a of which is fixed to the insertion hole 17 with solder or the like, and
Are connected to the various electronic components 15 constituting the electronic device. Antenna 6
Receives a transmitted radio wave and supplies a reception signal from a connection point (feed point) N to a reception circuit 5 including various electronic components 15.

The shield case 12 reduces the electromagnetic wave noise generated from the various electronic components 15 as described above, and also plays a role as a ground plane of the antenna 6. That is, the shield case 12 that is grounded has a mirror effect, and an antenna of an image based on an electric image is formed separately from the antenna 6, and the gain of the antenna 6 is improved. The length of the antenna 6 is determined by the frequency of radio waves used for the remote control device 1 and the like. For example, when a radio wave having a frequency of 300 MHz is used, the length of the antenna 6 is determined by the wavelength λ of the radio wave to be used (in this case,
Approximately 1/4 of about 1 m), for example, 25 cm.

A plurality of engagement holes 11b for mounting the antenna holder 13 are formed in the peripheral portion of the circuit board 11. On the other hand, each of the legs 18 of the antenna holder 13 is formed at one end thereof with an engagement claw 18a that engages with the engagement hole 11b. Then, the antenna holder 13 has its engaging claw 1
8a is fitted into the engagement hole 11b, so that the circuit board 1
It is fixed to 1 to prevent it from falling off.

The antenna holder 13 is formed with an antenna support 19 so as to connect the upper portions of the legs 18. A rising portion 19a is formed in one of the antenna support portions 19, and a guide groove 20 for raising the antenna 6 obliquely from the base end 6a in a direction away from the circuit board 11 is formed in the rising portion 19a. Is formed. A support groove 21 for supporting the antenna 6 is provided on each antenna support portion 19 and each leg 18 over substantially the entire circumference.
It is formed so as to be parallel to 1. That is, the support groove 21 is formed at a position separated from the circuit board 11. The length of the guide groove 20 and the support groove 21 is a length that can sufficiently accommodate the antenna 6.

Then, the antenna 6 is raised from the base end 6a by the guide groove 20, is fitted along the support groove 21 to the open end 6b, and is wired in parallel with the circuit board 11. The open end 6b is bent inward and inserted into and fixed to a fixing hole 21a formed in the antenna support portion 19. By the way, the antenna 6 launched from the circuit board 11
Falling again to the circuit board 11 for fixing the open end 6b of the antenna 6 leads to a decrease in the gain of the antenna 6. Therefore, in the present embodiment, the open end 6b of the antenna 6 is
The height does not become lower than the height raised from the circuit board 11, and a decrease in the gain of the antenna 6 is prevented.

Therefore, the antenna 6 is arranged along the inner peripheral surface of the housing recess 14a of the housing case 14, and
Most of the antenna 6 is supported by the circuit board 1 by the support groove 21.
1 and are spaced apart from one another. As a result, the antenna 6
The length of the shield case 12 can be increased, the transmitted radio wave can be easily received, and the effect of the shield case 12 as the ground plane can be effectively obtained.

As described above, the operation and effect of this embodiment will be described below. (1) A shield case 12 made of a conductive material is attached to the circuit board 11 so as to be grounded and cover various electronic components 15. Therefore, high-frequency electromagnetic noise generated from the various electronic components 15 can be reduced, and radio interference caused by the electromagnetic noise can be reduced.

Also, since the grounded shield case 12 serves as the ground plane of the antenna 6 to provide a mirror effect,
The gain of the antenna 6 can be improved. (2) The antenna 6 is provided in the housing recess 14 a of the housing case 14.
Are arranged along the inner peripheral surface of the antenna, and most of the antenna 6 is arranged at a distance from the circuit board 11 by the support groove 21, so that it is easy to receive the transmitted radio wave and the shield case 12 The effect as a ground plate can be effectively received. Therefore, the gain of the antenna 6 can be maximized within the determined space. By the way,
A helical antenna formed in a spiral shape may be considered in place of the above-mentioned antenna 6, but the antenna 6 does not increase the size of the receiver 4 because its occupied volume is smaller than that of the helical antenna.

(3) The antenna 6 is formed of a conductive wire. Therefore, the antenna 6 can be easily configured. (4) The antenna 6 is the guide groove 2 of the antenna holder 13.
0 and the support groove 21 are fitted and wired. Therefore, the antenna 6 is securely supported and fixed.

It should be noted that the present invention may be modified as follows, and in that case, the same operation and effect can be obtained. (1) In the above embodiment, the antenna 6 is supported by the antenna holder 13, but may be supported by the housing case 14. Further, the antenna holder 13 need not be particularly provided.

(2) In the above embodiment, the antenna 6 is supported by the support groove 21. However, the shape is not limited as long as the antenna 6 can be supported. Is also good.

(3) In the above embodiment, the guide groove 20
Has a shape that rises obliquely from the base end 6 a of the antenna 6 to the antenna support portion 19, but may have a shape that rises perpendicularly to the circuit board 11.

(4) In the above embodiment, the processing circuit 7
Is provided inside the vehicle body separately from the receiver 4, but the processing circuit 7 may be provided in the receiver 4 as an integrated type with the receiving circuit 5. (5) In the above embodiment, the antenna 6 is used for the receiver 4 of the remote control device 1 that locks and unlocks the door of an automobile, but is not limited to this. For example, it may be used for a receiver of a remote control device that starts and stops the engine.

While the embodiments of the present invention have been described above, technical ideas other than the claims that can be grasped from the embodiments will be described below together with their effects. (A) The receiver according to any one of claims 1 to 3, wherein the antenna drives an actuator provided in a vehicle based on a signal received by the antenna. With such a configuration, the antenna can reliably receive radio waves from the transmitter because a high gain is obtained, and the receiving circuit can reliably drive the actuator.

[0031]

According to the invention described in claim 1 or 2,
It is possible to provide a receiver capable of obtaining a high antenna gain in a fixed space.

According to the third aspect of the present invention, it is possible to provide a receiver capable of reliably supporting and fixing an antenna capable of obtaining a high gain.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a receiver according to the present embodiment.

FIG. 2 is a perspective view of a receiver.

FIG. 3 is an electrical configuration diagram of a remote control device.

[Explanation of symbols]

2 ... Transmitter, 5 ... Receiving Circuit, 6 ... Antenna, 11 ... Circuit Board, 12 ... Shield Case as Conductive Shield Member, 13 ... Antenna Holder as Support Member, 14 ... Accommodating Case, 14a ... Accommodating Recess, 14b ... opening, 15 ...
Various electronic components, N ... Connection points.

Claims (3)

[Claims] 1. A housing case (14) formed with a housing recess (14a) for housing various electronic components (15), and a radio wave from a transmitter (2) received in the housing case (14). The electronic component (1) mounted on a circuit board (11) fitted into the opening (14b) of the housing case (14).
And a receiving circuit (5) for receiving a signal received from the antenna (6), the circuit board (11) covering the various electronic components (15). ), A grounded conductive shield member (1)
2) The antenna (6) is mounted in a direction in which the antenna (6) is separated from the substrate (11) on which the shield member (12) is mounted.
From the connection point (N) with the receiving circuit (5), and wired along the inner peripheral surface of the housing recess (14a). 2. The receiver according to claim 1, wherein the antenna (6) is wired so as not to fall after rising from a connection point (N) with the reception circuit (5). Receiver. 3. The receiver according to claim 1, wherein the antenna (6) is wired along a support member (13) attached to the circuit board (11). Receiving machine.