JPH1041855A - Transmitter/receiver for image transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify configuration by separately making dedicated function circuits into units for a transmitter/receiver based on spread spectrum communication. SOLUTION: The regenerative digital image information of a VTR is transmitted from the antenna of a spread spectrum(SS) transmitter 20, this transmitted signal is received through a reception antenna by an SS receiver 40, and its image is projected on a monitor television. Then, the presence/absence of error in the transmitted image information is detected on the side of the receiver 40, and when an error is generated, a correction control signal is sent to the side of the transmitter 20 for retransmitting an erroneous image digital packet signal through weak radio waves or infrared rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter / receiver for transmitting image information by spread spectrum communication, and more particularly to a transmitter and a receiver each independently configured to enable image transmission in only one direction. The present invention relates to a transceiver for image transmission.

[0002]

2. Description of the Related Art A transmission unit for transmitting information by using spread spectrum communication represented by the 2.4 GHz band includes:
Until now, the transmission / reception function has been integrated into one unit without exception and made into a modem unit. This required such integrated transmission and reception functions to enable bidirectional data transmission. Such a modem unit has been used, for example, for transmitting FA information in a factory.

A conventional modem unit having a transmitting / receiving function will be described with reference to FIG. For example, in the case of use in FA, when transmitting information by exchanging information between certain two places, a data signal based on the information is transmitted to a quadrature modulator (MOD) 107 via an IC 105 for SS modulation / demodulation. Supplied and converter 106 and switcher 102
To the antenna 101, and from here to another modem unit 100 '(not shown).

When information responding to the transmitted information is transmitted from another modem unit 100 'to the modem unit 100, the information is first received by the antenna 101,
Through the switch 102, the RF converter 103, I
Data signals are output from the F stage 104 and the SS modulation / demodulation IC.

However, in the above-described conventional modem unit 100, two circuits, one for transmission and one for reception, are integrated so that bidirectional communication is possible. Therefore, when this modem unit is used only for one-way communication instead of two-way communication, there is a problem that one circuit is wasted and the modem unit itself becomes expensive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a unit having only a single function of transmission or reception and a simple confirmation control function (correction control function) between a transmitter and a receiver. An object of the present invention is to provide a simple and inexpensive image transmission / reception transceiver in the added spread spectrum communication.

[0006]

According to a first aspect of the present invention, there is provided a transmitter / receiver for image transmission according to the present invention.
In a transmitter / receiver for image transmission by spread spectrum communication, a transmitter in which at least an SS modulator, a mixer, and a filter are formed in one unit, and at least a filter, a mixer, and an SS demodulator are formed in one unit. And a receiver for receiving a transmission signal from the transmitter;
It consists of. According to the first aspect of the present invention, the transmitter and the receiver based on spread spectrum communication are each provided with a dedicated functional circuit as a separate unit, and are used only for a single purpose. A high quality image transmission / reception transceiver can be achieved.

According to a second aspect of the present invention, the SS modulator and the SS demodulator are formed by a DS / SS system. According to the second aspect of the present invention, high-speed transfer is possible, the synthesizer for the converter may be a general synthesizer used in a TV tuner, and the transmitting unit and the receiving unit may each be an SS. There is a feature that the circuits can be simplified by using only dedicated circuits for modulation and SS demodulation.

According to a third aspect of the present invention, there is provided a receiver, wherein the correctness of information transmitted from the transmitter to the receiver is confirmed, and when the error is confirmed, the correction control signal is transmitted by a weak radio wave. A weak radio wave transmitter to be transmitted to the transmitter side;
A weak radio receiver for receiving the correction control signal from the weak radio transmitter. According to the third aspect of the present invention, the transmitter and the receiver for the correction signal are of such a size that they handle weak radio waves, so that the transmitter and the receiver each have a simple configuration. Further, since the weak radio waves are non-directional, the arrangement positions of the transceivers are not limited.

According to a fourth aspect of the present invention, there is provided a receiver for confirming whether or not information transmitted from a transmitter to a receiver is correct, and when an error is confirmed, a correction control signal is transmitted by infrared rays to the transmitter. And an infrared receiver that is located on the transmitter side and receives the correction control signal from the infrared transmitter. According to the invention of claim 4,
The transmitter and the receiver for the correction signal use infrared rays, and the emission and reception of the infrared rays can be made with simple components including only diodes, and can be configured simply and inexpensively.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Spread spectrum communication used in the present invention.
ication) uses a frequency band of 2484 MHz ± 13 MHz (abbreviated as 2.4 GHz). FIG. 1 shows a conceptual diagram of the present invention. In the spread spectrum communication according to the present invention, for the purpose of transmitting image information, for example, VTR reproduced digital image information is transmitted from the antenna of the SS transmitter 20 (spectrum spread transmitter), and this transmission signal is received. The signal is received by the SS receiver 40 (spectrum spread receiver) via the antenna, and an image is displayed on the monitor television. S
The SS receiver 40 detects the presence or absence of an error in the image information transmitted from the S transmitter 20 to the SS receiver 40. If an error occurs, a correction control signal is transmitted to the SS transmitter 20 side by a weak radio wave or , By infrared, to transmit the wrong image digital packet signal again.

FIG. 2 is a specific circuit block diagram of the SS transmitter 20 of the transmitter / receiver for image transmission by spread spectrum communication according to the present invention. The reproduced image digital signal of the VTR 1 is supplied to the memory circuit 2, where it is formed into a packet-type signal block and stored. The data from the memory 2 is supplied to the SS modulator 3. The data signal from the memory 2 is supplied to the IC 4 for SS modulation, output as color difference signals I and Q, and supplied to the mixers 5 and 6, respectively. For the mixer 5, the transmitter 7 (VCO)
A 00 MHz signal is supplied, where the signal is mixed with the previous I signal, and further to the other mixer 6, a transmission signal having a 90 ° phase shift is supplied from the transmitter 7 and mixed with the Q signal to perform quadrature modulation. Is done.

The modulated output signal is supplied to a SAW filter 9 having a frequency of 400 MHz via an amplifier circuit 8. The output signal from this filter is supplied to the mixer circuit 11 from the oscillator VCO · 10 by the mixer 2.
0884MHz and the frequency 248
The frequency is converted to 4 MHz. A signal from the mixer circuit 11 is radiated from an antenna 14 via a power amplifier 12 and a filter 13. The frequency of the VCO 12 is controlled by a signal from the microcomputer 15 through a PLL circuit.

Reference numeral 16 denotes a control signal receiver which receives a control signal, which will be described later, and is supplied to the microcomputer 15 to control the same signal to be transmitted again when the packet signal of the digital image signal is erroneously transmitted. Note that in FIG.
An SS transmitter is constituted by each circuit indicated by 16.

FIG. 3 shows an SS receiver 40 for receiving a transmission signal from the SS transmitter 20. The transmission signal from the SS transmitter 20 received by the antenna 21 is supplied to the mixer circuit 24 via the filter 22 and the amplifier 23, where it is mixed with the frequency 2084 MHz from the VCO 26. The frequency-converted signal is 400 MH
z via the SAW filter 44 and the amplifier 28
The signal is supplied to the demodulation unit 29.

The signal from the amplifier 28 is supplied to the mixers 30, 3
1 and the transmission signal 400M from the transmitter 32
Hz, and the color difference signals I and Q are demodulated. Note that the transmission signals supplied from the transmitter 32 to the mixers 30 and 31 are relatively shifted by 90 degrees. The color difference signals I and Q are demodulated as digital image data and a clock signal CLK by the SS demodulator 33 and supplied to the memory 34. The digital signal from the memory is displayed on the display 3.
The VTR image information supplied to the VTR 5 and transmitted is projected.

The memory signal of the memory 34 is supplied to the microcomputer 36, which checks whether all the image packet signals from the SS transmitter 20 have been correctly received. For example, when a missing packet signal is found, the information is transmitted to the control signal receiver 16 on the transmitter side via the control signal transmitter 37. The control signal received by the control signal receiver 16 is sent to the microcomputer 15, the control signal is supplied to the memory 2 based on the control signal, and the signal missing due to the previous error is again transmitted by the transmitter 20 to the SS receiver 40. Is transmitted to the antenna 21. The signal thus retransmitted is normally reproduced by the SS receiver 40. The transmission and reception of the control signal are performed by a weak radio wave having a frequency of 300 MHz. The transmission power of the weak radio wave is determined by the SS transmitter 20 and the SS
By adjusting to the lowest power at the distance between the receivers 40, power can be saved. Since this weak radio wave is omnidirectional,
There is a feature that the positions of the S transceivers 20 and 40 are not restricted by each other.

S in the above spread spectrum communication system
The spread spectrum method in the S modulator 3 and the SS demodulator 29 is DS (direct sequence) / S
The S system (direct spectrum spread system) is adopted.
This system is capable of high-speed transfer and has a synthesizer (PL) that varies the frequency of the music selection transmitters 10 and 26.
L) can be easily configured (on the order of a TV tuner).

Next, an SS transceiver configured to transmit and receive a correction control signal using infrared light will be described with reference to FIGS. The same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted. In the SS transmitter 20 of FIG. 4, reference numeral 17 denotes an infrared receiver. This infrared receiver 17
Receives the signal from the transmitter 39 of the correction control signal from the SS receiver 40 shown in FIG.

The SS receiver 40 shown in FIG.
Is transmitted to the infrared receiver 17 by the infrared transmitter 39. In the infrared transceivers 17 and 39, the element for converting into infrared light may be a simple diode element, and the configuration can be simplified. If the above-mentioned SS transceiver is applied to, for example, a home VTR and a television, the VTR and the television can be easily connected wirelessly, and the VTR or the television can be arranged at an optimum free place where operation is easy. Becomes

[0020]

According to the first aspect of the present invention, the transmitter and the receiver based on spread spectrum communication each have a dedicated function circuit separately formed as a unit, and have only a single use. An image transmission / reception transceiver with a simple configuration and low cost can be achieved.

According to the second aspect of the present invention, high-speed transfer is possible, and a synthesizer for the converter may be a general synthesizer used in a TV tuner. Are for SS modulation and S respectively
There is a characteristic that the circuit can be simplified by using only a dedicated circuit for S demodulation.

According to the third aspect of the present invention, the transmitter and the receiver for the correction signal are of such a size that they handle weak radio waves, so that the transmitter and the receiver respectively have a simple configuration. Further, since the weak radio waves are non-directional, the arrangement positions of the transceivers are not limited.

According to the fourth aspect of the present invention, the transmitter and the receiver for the correction signal use infrared rays, and the light emission and reception of the infrared rays can be made of simple components including only diodes, and can be configured simply and inexpensively. .

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an SS transceiver according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram of an SS transmitter according to one embodiment of the present invention.

FIG. 3 is a circuit block diagram of an SS receiver according to one embodiment of the present invention.

FIG. 4 is a circuit block diagram showing a modified example of the SS transmitter shown in FIG. 2;

FIG. 5 is a circuit block diagram showing a modified example of the SS transmitter shown in FIG. 3;

FIG. 6 is a unit circuit block diagram of a conventional SS transceiver.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 VTR 2,34 Memory 3 SS modulation part 4 SS modulation IC 5,6,11,24,30,31 Mixer 7,10,26,32 VCO (Voltage control transmitter) 9,13,22 Filter 15,36 Microcomputer 16 Control signal receiver 17 Infrared receiver 20 SS transmitter 29 SS demodulator 37 Control signal transmitter 39 Infrared transmitter 40 SS receiver

Claims (4)

[Claims] An image transmitting / receiving apparatus for image transmission by spread spectrum communication, comprising: a transmitter in which at least an SS modulator, a mixer and a filter are formed in one unit, and at least a filter, a converter and an SS demodulator in one unit. And a receiver formed in the unit and receiving a transmission signal from the transmitter. 2. The SS modulation section and the SS demodulation section have a DS / S
2. The image transmission / reception transceiver according to claim 1, wherein the transmission / reception apparatus is an S system. 3. The apparatus of claim 1, further comprising the step of: confirming whether the information transmitted from the transmitter to the receiver is correct or not, and when the error is confirmed, transmitting a correction control signal by a weak radio wave to the transmitter. A weak radio wave transmitter for transmitting to the transmitter, and a weak radio wave receiver on the transmitter side for receiving the correction control signal from the weak radio wave transmitter. Item 3. A transceiver for image transmission according to Item 2. 4. The apparatus of claim 1, further comprising the step of: confirming whether the information transmitted from the transmitter to the receiver is correct or not, and transmitting a correction control signal to the transmitter by infrared when the error is confirmed. 3. An infrared transmitter for transmitting, and an infrared receiver on the transmitter side for receiving the correction control signal from the infrared transmitter. Transceiver for image transmission.