JP3961256B2 - Transmitter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmitter applicable to a radio wave keyless system used for unlocking and locking a vehicle door, for example.
[0002]
[Prior art]
Conventionally, as this type of device, for example, when a vehicle door is locked (locked) or unlocked (unlocked), a lock or unlock signal transmitted from a portable transmitter is used. A radio wave keyless system including a receiver that receives the signal and controls the driving of the actuator based on the signal is known in Japanese Patent Application Laid-Open No. 7-113365. This is explained below.
[0003]
That is, as shown in FIG. 9, the transmitter 2 incorporates the transmitter 2 in the grip portion 1a of the ignition key 1 of the vehicle provided with a key plate 1b provided with a keyway at one end.
As shown in FIG. 12, the transmitter 2 includes a transmission switch 5, a first CPU 6, a first memory 7, a signal output circuit 8, and a transmission unit 9, which are formed on a single printed board 3.
As shown in FIG. 12, the receiver 10 attached to the vehicle side includes a receiver 11, a signal input circuit 12, a second CPU 13, a second memory 14, and a drive circuit 15, and an actuator 16 is driven by the output of the drive circuit 15. When driven, the automobile door is locked or unlocked.
The radio wave output from the transmitter 2 is simultaneously output from the pair of antennas 17 and 18 connected in parallel to the antenna 19 of the receiver 10.
[0004]
Next, the transmitting antennas 17 and 18 of the transmitter 2 will be described with reference to FIG.
One of the transmission antennas 17 and 18 (hereinafter referred to as a horizontally polarized antenna) 17 is formed by a printed pattern formed on the back surface of the printed circuit board 3, and the other transmission antenna ( (Hereinafter referred to as a vertically polarized antenna) 18 is formed of a metal plate, and is attached by both end horizontal portions 18a and 18a.
As a result, a radio wave having a polarization plane parallel to the substrate surface of the printed circuit board 3 is output from the horizontally polarized antenna 17, and a polarization perpendicular to the substrate surface of the printed circuit board 3 is output from the vertical polarization antenna 18. A radio wave having a wavefront is output.
[0005]
Accordingly, when the transmission switch 5 is turned on (FIG. 13A), the horizontally polarized radio wave is output from the horizontal polarization antenna 17 (FIG. 13B), and the vertically polarized radio wave is transmitted to the vertical polarization antenna 18. Are simultaneously output (FIG. 13C), and the output vertically and horizontally polarized waves are combined and output.
That is, as a reason for using both vertical polarization and horizontal polarization, in a vehicle, a window is small, and a plate-shaped metal column is provided between the windows. This is due to the fact that the good part and bad part of the reception directivity of the receiving antenna are complicated and disturbed.
[0006]
[Problems to be solved by the invention]
However, the magnitude of the output of the radio wave output from the transmitter is regulated by the government of the country according to the purpose of use. For example, in the case of weak radio waves, it is regulated below the regulated output.
That is, in the case of a radio wave in which the vertically polarized radio wave and the horizontally polarized radio wave are combined as described above, by simultaneously driving the two transmitting antennas 17 and 18, the polarization of the radio wave is changed to the combined wave. It is necessary to satisfy the regulation output with the synthesized wave.
Accordingly, when viewed from the components of each horizontal polarization and vertical polarization, a loss occurs, so that a prescribed output cannot be produced and the communication performance deteriorates.
[0007]
On the other hand, when using a conventional type keyless transmitter with one antenna, the user changes the direction of the transmitter or does not hold it when the door is not locked or unlocked by a single switch operation. The door was locked and unlocked by changing the direction.
That is, as shown in FIG. 14, when the transmission switch 5 is turned on with the flat surface of the gripping portion 1a being horizontal (the substrate surface of the printed circuit board 3 is horizontal), a horizontally polarized radio wave is output from the antenna and received. The characteristic shown by the solid line in FIG. 11 is obtained.
Further, as shown in FIG. 15, when the transmission switch 5 is turned on with the flat surface of the grip portion 1a vertical (the printed circuit board 3 is vertical), it is as if the vertically polarized radio wave is output from the antenna. The reception characteristic indicated by the broken line in FIG. 11 is obtained.
[0008]
Therefore, in the present invention, a method of efficiently transmitting radio waves within the regulated output value by shifting the timing of the horizontally polarized radio wave and the vertically polarized radio wave, for example, alternately. And providing an apparatus.
[0009]
[Means for Solving the Problems]
The transmitter according to the present invention includes a transmission signal generation unit that generates a transmission signal upon receiving a transmission trigger, and a horizontal bias that receives the transmission signal from the transmission signal generation unit and outputs the transmission signal as a radio wave. A wave antenna and a vertically polarized antenna, and a transmission unit that directly supplies the transmission signal to the one antenna and supplies a transmission signal having the same content as the transmission signal to the other antenna with a delay. One of the horizontally polarized antenna and the vertically polarized antenna is a printed pattern formed over the entire periphery of one surface of the printed circuit board on which the transmission signal generating unit is mounted, The other consists of a metal plate formed over the entire length of the other surface of the printed circuit board.
[0010]
One of the horizontally polarized antenna and the vertically polarized antenna is a printed pattern formed over the entire circumference of one side of the printed circuit board on which the transmission signal generating unit is mounted, and the other is By comprising a metal plate formed over the entire length of the other surface of the printed circuit board, the antenna opening area can be increased, communication performance can be ensured, and the transmitter can be made thinner.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment according to the present invention will be described below. The transmitter 20 according to the present invention includes an upper case 21, a lower case 22 fitted to the upper case, and the lower case as shown in FIGS. PCB 23 housed in 22, transmit switch 24 which is mounted on the printed circuit board 23, first 1CPU25, first memory 26, the signal output circuit 27, the first transmission portion 28, the second transmission unit 29, delay circuits 31 , Button type battery 32 and the like. Here, the transmission switch 24, the first CPU 25, the first memory 26, and the signal output circuit 27 constitute a transmission signal generation unit, and the first transmission unit 28, the second transmission unit 29, and the delay circuit 31 constitute a transmission unit. Yes. (In the figure, reference numeral 24a denotes an operation knob of the transmission switch 24.)
[0012]
A horizontal polarization antenna 33 and a vertical polarization antenna 34 are formed and mounted on the printed board 23.
That is, the horizontal polarization antenna 33 is formed by a printed pattern over the entire outer periphery of the back surface of the printed circuit board 23 in the same manner as the horizontal polarization antenna 17 of the prior art, and the vertical polarization antenna 34 is It is obtained by forming a metal plate similar to the vertically polarized antenna 18 of the technology in a U shape and over the entire length in the surface length direction of the printed board 23.
[0013]
Next, a method of driving the horizontally polarized antenna 33 and the vertically polarized antenna 34 will be described with reference to the drawings.
[0014]
Embodiment 1 FIG.
This embodiment will be described below with reference to FIGS.
In the figure, a transmitter 20 includes a transmission switch 24, a first CPU 25 that reads transmission data from a first memory 26 described later based on a switch operation of the transmission switch 24, a first memory 26 that stores transmission data, and the first 1 A signal output circuit 27 that outputs the transmission data from the CPU 25 as radio wave transmission data and outputs the radio wave transmission data from the signal output circuit 27 to a first transmission antenna (hereinafter referred to as a horizontal polarization antenna) 33 The first transmission unit 28, the delay circuit 31 that outputs the radio wave transmission data from the signal output circuit 27 with a delay of a predetermined time T, and the radio wave transmission data from the delay circuit 31 is transmitted to the second transmission antenna (hereinafter, vertical). The second transmitter 29 is supplied to a polarization antenna 34, and these are mounted on the printed circuit board 23.
[0015]
In the above configuration, when the transmission switch 24 is turned on (FIG. 6A), transmission data read from the first memory 26 by the first CPU 25 is supplied to the first transmission unit 28 via the signal output circuit 27, and is used for horizontal polarization. A horizontally polarized radio wave, that is, transmission data is output from the antenna 33 (FIG. 6B), and the same transmission data is delayed by a predetermined time T via the delay circuit 31 and supplied to the second transmission unit 29. Then, it is output as a vertically polarized radio wave from the vertically polarized antenna 34 (FIG. 6C).
[0016]
Embodiment 2. FIG.
This embodiment will be described below with reference to FIGS. In this embodiment, transmission data is divided into two and output. The first transmission unit 28 and the second transmission unit 29 shown in FIG. In this configuration, the output of the transmitter 28 is supplied to the horizontal polarization antenna 33 and the vertical polarization antenna 34 at different timings via the changeover switch 30 .
That is, the output from the transmission switch 24 is output in parallel to both the third CPU 36 and the delay circuit 31. The third CPU 36 reads the transmission data from the first memory 26, supplies the read transmission data to the signal output circuit 27 twice in succession (FIG. 8C), and the signal output circuit 27 is based on the received transmission data. The radio wave transmission data is generated and output to the transmission unit 28. Further, the delay circuit 31 that has received the output from the transmission switch 24 delays it by a predetermined time T and outputs it to the switching circuit 30 (FIG. 8B). The delay time T is set to half of the frame time of the signal that is continuously output twice from the CPU 36.
[0017]
In the above configuration, when the transmission switch 24 is turned on, the switch signal shown in FIG. 8A is supplied from the transmission switch 24 to both the third CPU 36 and the delay circuit 31, and the third CPU 36 reads the transmission data from the first memory 26. The transmission data is continuously output twice to the transmission unit 28 via the signal output circuit 27 (FIG. 8C). At that time, since the terminals of the switching circuit 30 are connected as shown by a solid line, the output from the transmitter 28 is the output of the horizontally polarized radio wave from the horizontally polarized antenna 33 (FIG. 8D). At the same time when the output is completed, the connection state between the terminals of the switching circuit 30 is switched from the solid line state to the broken line state by the output from the delay circuit 31, so that the output of the vertically polarized radio wave is changed to the vertically polarized antenna. 34 (FIG. 8E).
[0018]
In the above-described embodiment, the transmission data is set so that the vertically polarized radio wave is output from the vertically polarized antenna 34 immediately after being horizontally polarized and output from the horizontally polarized antenna 33. However, when the transmission data is set so that the vertically polarized radio wave is output from the vertically polarized antenna 34 after a predetermined time has passed immediately after the horizontally polarized wave output from the horizontally polarized antenna 33 is output. In some cases, however, the predetermined time is determined by the magnitude of the antenna inductance.
[0019]
【The invention's effect】
According to this invention, in response to the transmission trigger, the drive timings of both the horizontally polarized antenna and the vertically polarized antenna are shifted, and the same signal is output as the horizontally polarized signal and the vertically polarized signal. In addition, the wattage of an electronic element in a driving stage such as a transistor for driving an antenna can be reduced, and it can be directly driven by an output of an integrated circuit. As a result, hardware costs can be reduced.
[0020]
In addition, one of the horizontally polarized antenna and the vertically polarized antenna is formed by a printed pattern formed over the entire circumference of one peripheral surface of the printed board on which the transmission signal generating unit is mounted. Since the other is constituted by a metal plate formed over the entire length of the other surface of the printed circuit board, a large opening area can be obtained by using both antennas effectively using the entire area of the printed circuit board. Communication performance can be improved.
[0021]
Further, since the horizontal polarization antenna and the vertical polarization antenna are driven independently, the output wattage can be reduced.
[0022]
[Brief description of the drawings]
FIG. 1 is an external plan view of a transmitter according to the present invention.
FIG. 2 is a cross-sectional explanatory view taken along line XX in FIG.
3A is a cross-sectional view of the upper case 21 extracted from FIG. 2, FIG. 3B is a cross-sectional view of the transmission circuit extracted from FIG. 2, and FIG. 3C is a cross-sectional view of the lower case extracted from FIG. FIG.
4A is an explanatory plan view of the upper case 21 extracted from FIG. 2, FIG. 4B is an explanatory plan view of the transmission circuit extracted from FIG. 2, and FIG. 4C is a plan view of the lower case 22 extracted from FIG. It is explanatory drawing.
FIG. 5 is an explanatory circuit block diagram of a transmission circuit 20 and a reception circuit 10 for explaining the first embodiment according to the present invention;
6 is a timing chart illustrating the operation of FIG.
7 is a circuit block explanatory diagram of a transmission circuit 20 ′ and a reception circuit 10 for explaining a second embodiment according to the present invention. FIG.
FIG. 8 is a timing chart for explaining the operation of FIG.
FIG. 9 is a partial sectional perspective view of a conventional ignition key 1.
10 is an enlarged explanatory diagram of the antennas 14 and 15 in FIG. 9. FIG.
FIG. 11 is a reception sensitivity characteristic diagram (solid line) of a vehicle-mounted receiver using horizontal polarization output from the antennas 14 and 15 in FIGS. 9 and 10, and a reception sensitivity characteristic diagram of a vehicle-mounted receiver using vertical polarization ( (Broken line).
12 is an explanatory circuit block diagram of the transmitter 2 and the vehicle-mounted receiver 10 shown in FIG. 9;
13 is a timing chart for explaining the circuit operation of FIG. 12. FIG.
14 is a diagram for explaining a state in which the transmitter in FIG. 9 is leveled. FIG.
15 is a diagram illustrating a state in which the transmitter in FIG. 9 is vertical. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ignition key 1a Grip part 1b Key plate 2 Transmitter 3,23 Printed circuit board 5,24 Transmission switch 6,13,25,36 CPU
7, 14, 26 Memory 8, 27 Signal output circuit 9, 28, 29 Transmitter 10 Receiver 11 Receiver 11 Signal input circuit 15 Drive circuit 16 Actuator 19 Antenna 21 Upper case 22 Lower case 30 Switching circuit 31 Delay circuit 33 Print pattern (Horizontal polarization antenna)
34 Metal plate (vertically polarized antenna)

Claims (1)

A transmission signal generator that generates a transmission signal upon receiving a transmission trigger, a horizontal polarization antenna that receives the transmission signal from the transmission signal generator and outputs the transmission signal as a radio wave, and a vertical polarization An antenna; and a transmission unit that directly supplies the transmission signal to the one antenna and supplies a transmission signal having the same content as the transmission signal to the other antenna with a delay , the antenna for horizontal polarization And one of the vertically polarized antennas is a printed pattern formed over the entire circumference of one peripheral surface of the printed circuit board on which the transmission signal generating unit is mounted, and the other is the other of the printed circuit board. A transmitter comprising a metal plate formed over the entire length in the length direction of the surface.

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