JPH09266571A - Image transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit the image signals of plural cameras or high-resolution image signals while using ordinary band width of one channel of image signals by selectively sending the outputs of plural video cameras. SOLUTION: The output of a camera designated signal superimposing circuit 6 is transmitted from a transmitter 7 to a receiver 8. Then, a video memory 11 is made to correspond to a camera 1, a video memory 13 is made to correspond to a camera 2, and a video memory 15 is made to correspond to a camera 3. The memories 11, 13 and 15 update stored contents only when a storage command is received. Besides, the contents of the respective video memories are always read out according to the scan patterns of cameras, converted to video signals and outputted. The output of the memory 11 is inputted to a display device 12 and displayed, the output of the memory 13 is inputted to a display device 14 and displayed and the output of the memory 15 is inputted to a display device 16 and displayed respectively as images. As a result, images for three video cameras can be alternately transmitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave image transmission device for application to a remote monitoring system or the like.

[0002]

2. Description of the Related Art FIG. 11 shows a conventional image transmission device, in which 38 is a video camera, 7 is a transmitter, 8 is a receiver, and 3 is a receiver.
9 is a display device. The image signal obtained by the video camera 38 enters the transmitter 7. There, it is converted into a radio wave for transmission and transmitted to the receiver 8. The receiver 8 extracts an image signal from the received radio wave and sends it to the display device 39. The display device 39 displays the input image signal. Since the conventional image transmission apparatus is configured in this way, it can transmit only the image signal of one camera at a time.

[0003]

On the other hand, in order to perform more effective surveillance, there is an increasing demand for a system equipped with a plurality of video cameras such as an infrared video camera in addition to the conventional visible video camera. Going on,
There has been a demand for transmitting image signals from a plurality of cameras. In addition, there is an increasing number of cases where a video camera to be used has a higher resolution than conventional popular products such as a high-definition video camera.

However, not only in Japan but also in many countries, there are almost no unused frequency bands, and it is very difficult for a user to obtain a license to use a new frequency band.

A normal image transmission device is designed to transmit 30 screens per second in order to make the motion of an image look smooth. However, it is not always necessary to transmit the entire screen at this rate for monitoring purposes. In many cases, it is safe to thin the screen for transmission. Therefore, an image transmission device capable of transmitting image signals of a plurality of cameras and a high resolution image signal of a high definition video camera or the like is realized by using a frequency band having a bandwidth of a normal image signal channel. The purpose is to

[0006]

According to a first aspect of the present invention, there is provided an image transmission apparatus comprising a plurality of cameras which operate in synchronization, means for designating which camera is selected in synchronization with the cameras, and image signals of the designated cameras. Means for selecting and outputting, a means for superimposing a signal designating the currently selected camera on the selected image signal, and a transmission for transmitting an image signal on which a signal indicating the currently selected camera is superimposed Machine,
A means for receiving the output of the transmitter, a means for detecting a signal indicating the currently selected camera from the received image signal, the same number of video memories as the cameras, and a video corresponding to the currently selected camera. Means for generating a command signal for designating a memory and storing image data being received is provided.

Further, the image transmission apparatus of the second invention comprises a plurality of cameras operating in synchronization, a first camera designating means for designating which camera is selected in synchronization with the cameras, and the first camera designating means. A first timer circuit for initializing at a predetermined time, means for selecting and outputting an image signal of a designated camera, a transmitter for transmitting the selected image signal,
Determines the means for receiving the output of the transmitter, the same number of video memories as the cameras, the second camera designation means for designating which camera to select in synchronization with the received image signal, and the second camera designation means. A second timer circuit that initializes at a designated time is provided.

An image transmitting apparatus of a third invention is a high resolution video camera, a first memory for storing an image output by the high resolution video camera, and an image signal output by the high resolution camera, which is converted into digital data. Memory writing circuit for writing in the memory, a sync signal generating circuit for generating the same sync signal as that of a camera having a normal resolution, and a memory reading area determined based on the sync signal generated by the sync signal generating circuit. A region designating circuit for receiving the synchronizing signal generated by the synchronizing signal generating circuit, reading data in a region designated by the region designing circuit from a memory during an effective scanning period, converting the data into an analog signal, and superimposing the synchronizing signal; Of the memory reading circuit, generates an image pattern corresponding to the designated area output from the area designating circuit, and outputs it to the first memory reading circuit. Area designating signal superimposing circuit for superimposing and outputting in the blanking period of the output signal of the output circuit, a transmitter for transmitting the output of the area designating signal superimposing circuit, a receiver for receiving the output of the transmitter, and a receiver for the receiver. An area designating signal detection circuit that detects an image pattern corresponding to the area designating signal from the output, converts the image pattern into an area designating signal and outputs the area designating signal, receives the area designating signal, and stores the image in a corresponding area of the second memory. A second memory writing circuit that converts the image signal output from the receiver into digital data and writes the digital signal, and a second memory reading circuit that reads the contents of the second memory according to the scanning pattern of the high resolution camera and converts the contents into an analog signal. Equipped with.

The image transmission apparatus of the fourth invention is a high resolution video camera, a first memory for storing an image output by the high resolution video camera, and an image signal output by the high resolution camera as digital data. A first memory writing circuit for converting and writing to the memory, a sync signal generating circuit for generating the same sync signal as a camera having a normal resolution, and a read area of the memory based on the sync signal generated by the sync signal generating circuit. The first reset type area designation circuit that determines
A first timer circuit that measures time and initializes the first reset-type area designating circuit at a predetermined time, receives a synchronization signal generated by the synchronization signal generating circuit, and operates the area designating circuit during an effective scanning period. A first memory read circuit that reads data in a specified area from the memory and converts the data into an analog signal and superimposes the synchronization signal, a transmitter that transmits the output of the memory read circuit, and receives the output of the transmitter Receiver, sync signal separation circuit for separating sync signal from output of the receiver, second reset type area designation circuit, second timer for initializing the second reset type area designation circuit at a predetermined time The circuit, the second memory, and the area designating signal output from the second reset-type area designating circuit are received, and the image signal output from the receiver is digitized in the corresponding area of the second memory. According scan pattern of the second memory write circuit and the high-resolution video camera is written to convert the data read out the contents of the second memory comprises a second memory read circuit for converting the analog signal.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. 1 is a block diagram showing a first embodiment of the present invention, in which 1 is a first video camera, 2 is a second video camera, 3 is a third video camera, 4 is a camera designation circuit, 5 Is an image signal selection circuit, 6 is a camera designation signal superposition circuit, 7 is a transmitter, 8 is a receiver, 9 is a camera designation signal detection circuit, 10 is a decoding circuit, 11 is a first video memory, and 12 is a first video memory. A display device, 13 is a second video memory, 14 is a second display device, 15 is a third video memory, and 16 is a third display device.

The first video camera 1, the second video camera 2 and the third video camera 3 are, for example, NTSC (N
national Television Standard
An ordinary image signal such as the rdCommittee method is output.

In a normal image signal, a blanking period in which no image information is included is inserted following an effective period in which image information for one scanning line is sent. In addition, in a normal image signal, an image signal for each scanning line is sequentially sent from the upper part of the screen to the lower part. When the image information for one screen is sent, the image corresponding to the upper scanning line of the screen is again displayed. The operation of sending information is repeated. The blanking period inserted between the screens is longer than the normal blanking period. Further, the synchronization signal is a signal having a pulse having a time width shorter than this in the blanking period. Further, since the pulse inserted between the screens has a different pattern from that inserted during the normal blanking period, the sync signal is inspected to detect the scan line switching time and the screen switching time. be able to.

The second video camera 2 and the third video camera 3 receive the synchronization signal output from the first video camera 1 and operate in synchronization with it. The camera designating circuit 4 receives the synchronizing signal of the first video camera 1 and sends a signal designating the first camera 1, the second video camera 2 and the third video camera 3 to the screen and the next screen. The output is sequentially switched in the period between. The image signal selection circuit 5 receives the output of the camera designation circuit 4 and outputs a corresponding image signal. The camera designation signal superimposing circuit 6
First, an image pattern corresponding to the camera designation signal is generated. The image pattern may be composed of a series of patterns including a white pattern and a black pattern. For example, the first camera 1 has two continuous white patterns, the second camera 2 has a set of a white pattern and a black pattern, The third camera 3
May be represented by two continuous black patterns.
By superimposing this pattern on the blanking period of the image signal, the camera designation information can be inserted without damaging the original image signal. The camera designation signal superimposing circuit 6 superimposes the camera designation signal on the input image signal and outputs the superposed signal.

The signal output from the camera designation signal superimposing circuit 6 enters a transmitter 7, which converts the signal into a radio wave and transmits it to a receiver 8. The receiver 8 converts the received radio wave into the original signal and outputs it. Camera designation signal detection circuit 9
Receives the output of the receiver 8, detects the image pattern superimposed in the blanking period, converts the image pattern into a camera designation signal, and outputs the signal. The decoding circuit 10 receives the camera designation signal and issues an image storage command to the video memory corresponding to the designated camera. In the case of this embodiment, the first camera 1 has a first video memory 11, the second camera 2 has a second video memory 13 and the third camera 3.
Corresponds to the third video memory 15.
The contents stored in the first video memory 11, the second video memory 13, and the third video memory 15 are updated only when a storage command is received. Further, these video memories are constructed so that the contents thereof are always read according to the scanning pattern of the camera, converted into a video signal and outputted. The output of the first video memory 11 is input to the first display device 12 and displayed as an image. The output of the second video memory 13 is input to the second display device 14 and displayed as an image. The output of the third video memory 15 is input to the third display device 16 and displayed as an image. FIG. 5 is a timing chart showing the operation of this embodiment described above, and shows the correspondence between the output of each video camera and the output of each video memory. Further, FIG. 6 is a timing diagram showing a situation in which the camera designation signal is superimposed.
The part which designates the said 1st video camera, the said 2nd video camera, and the said 3rd video camera which are superimposed on a vertical blanking period is shown.

Since this embodiment is constructed as described above, an image for three video cameras is alternately transmitted by using a transmitter and a receiver which have an ordinary image signal one channel transmission capacity. it can. In this case, the update rate of the image displayed on each display device is one third of the original image update rate of the video camera.

Embodiment 2 2 is a configuration diagram showing a second embodiment of the present invention, in which 17 is a first timer circuit, 18 is a first reset type camera designating circuit, and 19 is a circuit.
Is a sync signal separation circuit, 20 is a second reset type camera designation circuit, and 21 is a second timer circuit.

The first timer circuit 17 measures the time and initializes the first reset type camera designating circuit 18 at the determined time. As a method for the first timer circuit 17 to measure the time, for example, a time signal by short wave broadcasting is used. When initialized, the first reset type camera designating circuit 18 designates the first video camera 1 first. After that, the designated cameras are switched in the order of the second video camera 2 and the third video camera 3 as in the first embodiment. The image signal switching circuit 5, the transmitter 7, and the receiver 8 operate in the same manner as in the first embodiment. The sync signal detection circuit 19 receives the output of the receiver 8, detects the sync signal included in the image signal, and outputs it to the second reset type camera designation circuit 20. The second timer circuit 21 measures the time and measures the time.
The second reset type camera designating circuit 20 is initialized at the same time as 7. The second reset type camera designation circuit 20
Operates in the same manner as the first reset type camera designating circuit 18, and when initialized, first the first video camera 1
Then, the designated camera is switched in the order of the second video camera 2 and the third video camera 3 in the same manner. The decoding circuit 10, the first video memory 11, the second video memory 13, the third video memory 15, the first display device 12, the second display device 14, and the third display device 16 are the same as those in the first embodiment. Works the same as. FIG. 7 is a timing chart showing the operation of this embodiment described above, and shows the correspondence between the output of each video camera and the output of each video memory.

Since this example is constructed as described above, the display image is updated at the same rate as in the first embodiment.

Embodiment 3 3 is a block diagram showing a third embodiment of the present invention, in which 22 is a high resolution video camera, 23 is a first memory, 24 is a first memory writing circuit, 25 is a synchronizing signal generating circuit, 26 is a first area specifying circuit, 27 is a first memory reading circuit, 28 is an area specifying signal superimposing circuit, 29 is an area specifying signal detecting circuit, 30 is a second memory writing circuit, 31 is a second memory. , 32 is a second memory reading circuit, and 33 is a high resolution display device.

The high resolution video camera 22 is, for example, an HD
TV (High Definition Television)
The image signal of high definition such as the sine system is output.

The first memory 23 stores the image output from the high resolution video camera 22. The first memory writing circuit 24 receives the high-definition image signal output from the high-resolution video camera 22, digitizes it, and writes it in the first memory 23. The sync signal generation circuit 25 generates the same sync signal as that of a normal resolution camera. The area designating circuit 26 determines the reading area of the image stored in the first memory 23 based on the sync signal generated by the sync signal generating circuit 25. First memory reading circuit 27
Receives the synchronizing signal generated by the synchronizing signal generating circuit 25 and the area designating signal output by the area designating circuit 26, reads the image data of the designated area from the first memory 23, and outputs the analog data of the effective scanning period. While converting to a signal,
The sync signal is superimposed and output as a normal video signal. The area designating signal superimposing circuit 28 includes the area designating circuit 2
An image pattern corresponding to the designated area data output by 6 is generated, and the image pattern is superimposed and output during the blanking period of the output video signal of the first memory reading circuit 27. The transmitter 7 and the receiver 8 operate similarly to the first embodiment.

The area designation signal detection circuit 29 receives the output of the receiver 8, detects the image pattern superimposed in the blanking period, converts it into an area designation signal, and outputs it.
The second memory writing circuit 30 receives the area designating signal and converts the image signal output from the receiver into digital data and writes it in the corresponding area of the second memory 31. The second memory 31 is a memory having the same resolution (number of pixels) as that of the high resolution video camera 22. The second memory reading circuit 32 reads all the image data from the second memory 31 and converts it into a video signal equivalent to the output video signal of the high resolution video camera 22. The high resolution display device is, for example, an HDTV monitor and receives an output of the second memory reading circuit 32 to display an image with high definition. FIG. 8 is a diagram showing the regions of the output image of the high-resolution camera designated by the region designation circuit, and showing the positions of the regions 1 to 4 on the screen. FIG. 9 is a timing chart showing the operation of this embodiment described above, and shows the correspondence between the transmission timing of each area and the video memory output.

Since this embodiment is configured as described above, the partial update rate (for each divided area) of the image displayed on the display device is lower than the original update rate of the image of the high resolution video camera. However, it is possible to transmit images from a high resolution video camera by using a transmitter and a receiver that have only the transmission capability for one normal image signal channel.

Embodiment 4 4 is a configuration diagram showing a fourth embodiment of the present invention. In the figure, 34 is a first reset type area designation circuit and 35 is a second reset type area designation circuit.

The first timer circuit 17 operates in the same manner as in the second embodiment, measures the time, and initializes the first reset type area designation circuit 34 at the determined time. When the first reset type area designation circuit 34 is initialized, it is a determined area in the high resolution image (for example, the 1/4 screen area at the upper left corner).
Is specified. Thereafter, for example, the designated area is switched in the order of the upper right quarter screen area, the lower left quarter screen area, and the lower right quarter screen area. The transmitter 7 and the receiver 8 operate similarly to the first embodiment. Sync signal detection circuit 19
Receives the output of the receiver 8 and detects the synchronizing signal included in the image signal, and outputs it to the second reset type area designating circuit 35. The second timer circuit 21 measures the time and initializes the second reset type area designation circuit 35 at the same time as the first timer circuit 17. The second reset-type area designating circuit 35 operates similarly to the first reset-type area designating circuit 34, and sequentially switches the area designation based on the synchronization signal after initialization. The second memory writing circuit, the second memory 31, the second memory reading circuit 32 and the high resolution display device 33 operate in the same manner as in the third embodiment. FIG. 10 is a timing chart showing the operation of this embodiment described above, and shows the correspondence between the transmission timing of each area and the video memory output.

Since this embodiment is constructed as described above, the display image is updated as in the third embodiment.

[0027]

According to the first aspect of the present invention, instead of transmitting all the images of a plurality of video cameras in perfect real time (1/30 seconds), the images of a large number of video cameras are time-sequentially multiplexed and are normally used. It becomes possible to transmit the television signal in one wireless transmission band, and it is possible to easily construct a simultaneous monitoring system by wireless transmission of images from a large number of cameras.

According to the second invention, the same effect as that of the first invention is obtained, and the camera designating signal superimposing circuit and the camera designating signal detecting circuit are not required, so that the apparatus can be simplified.

According to the third invention, instead of transmitting the image of the high-resolution video camera in completely real time (1/30 seconds), the image of the high-resolution video camera is time-sequentially multiplexed for each area and the normal resolution is obtained. It becomes possible to transmit in one wave of the wireless transmission band of the television signal, and the monitoring system by wireless transmission of the image of the high resolution video camera can be easily constructed.

According to the fourth invention, the same effect as that of the third invention is obtained, and the camera designating signal superimposing circuit and the camera designating signal detecting circuit are not required, so that the apparatus can be simplified.

[Brief description of drawings]

FIG. 1 is a first embodiment of an image transmission device according to the present invention.
FIG.

FIG. 2 is a second embodiment of the image transmission device according to the present invention.
FIG.

FIG. 3 is a third embodiment of the image transmission device according to the present invention.
FIG.

FIG. 4 is a fourth embodiment of the image transmission device according to the present invention.
FIG.

FIG. 5 is a diagram showing an operation timing according to the first embodiment.

FIG. 6 is a diagram showing a camera designation signal according to the first embodiment.

FIG. 7 is a diagram showing an operation timing according to the second embodiment.

FIG. 8 is a diagram showing an area set in an output image of the high resolution camera according to the third embodiment.

FIG. 9 is a diagram showing the operation timing of the third embodiment.

FIG. 10 is a diagram showing operation timing in the fourth embodiment.

FIG. 11 is a diagram showing a conventional image transmission device.

[Explanation of symbols]

1 first video camera, 2 second video camera, 3
Third video camera, 4 camera designation circuit, 5 image signal selection circuit, 6 camera designation signal superposition circuit, 7 transmitter, 8 receiver, 9 camera designation signal detection circuit, 10
Decoding circuit, 11 first video memory, 12 first display device, 13 second video memory, 14 second display device, 15 third video memory, 16 third display device, 17 first timer Circuit, 18 First reset type camera designation circuit, 19 Sync signal detection circuit, 20
Second reset type camera designating circuit, 21 Second timer circuit, 22 High resolution video camera, 23 First memory, 24 First memory writing circuit, 25 Sync signal generating circuit, 26 First area designating circuit , 27 first memory read circuit, 28 area designation signal superposition circuit, 29 area designation signal detection circuit, 30 second memory write circuit, 31
Second memory, 32 Second memory reading circuit, 33 High resolution display device, 34 First reset type area designation circuit, 35 Second reset type area designation circuit.

Claims (4)

[Claims] 1. A first video camera, one or more video cameras that receive a synchronization signal output from the first video camera, and output an image signal at the same timing as the first video camera, the video A camera designating circuit for generating a signal designating one of the cameras and switching the camera designating signal based on a synchronization signal output from the first video camera, and each video camera receiving the output of the camera designating circuit Image signal selecting circuit for selecting and outputting one of the image signals output from the image specifying circuit, and generating an image pattern corresponding to the output of the camera specifying circuit on a one-to-one basis and outputting the image pattern to the image signal selecting circuit. A camera designation signal superimposing circuit for superimposing and outputting in a ranking period, a transmitter for transmitting a signal output by the camera designation signal superimposing circuit,
A receiver for receiving a signal output by the transmitter, a camera designation signal detection circuit for receiving a signal output by the receiver, detecting an image pattern superimposed in a blanking period, and outputting a camera designation signal, the receiver The same number of video memories as the video camera, which stores and reproduces the image signal output by the camera, receives the output of the camera designation signal detection circuit, selects one video memory corresponding to the camera designation signal, and issues an image storage command. An image transmission device comprising a decoding circuit and a display device for displaying an image in each of the video memories. 2. A first video camera, one or more video cameras that receive a synchronization signal output from the first video camera and output an image signal at the same timing as the first video camera, and the video. A first reset-type camera designation for generating a signal designating one of the cameras and switching the camera designation signal based on the synchronization signal output from the first video camera and the output of the first timer circuit. Circuit, a first timer circuit that measures time and initializes the reset type camera designation circuit at a fixed time, one of the image signals output from each video camera in response to the output of the reset type camera designation circuit An image signal selection circuit for selecting and outputting, a transmitter for transmitting a signal output by the image signal selection circuit, a receiver for receiving a signal output by the transmitter, and a second A timer circuit, a sync signal separation circuit for separating a sync signal from an image signal output from the receiver, a second reset-type camera designation circuit initialized by the sync signal and a second timer circuit, and an output of the receiver The same number of video memories as the above-mentioned video cameras, which stores and reproduces the image signals, receives one output from the second reset type camera designation circuit, selects one of the video memories corresponding to the camera designation signals, and stores the images. An image transmission device comprising: a decoding circuit for issuing a command; and a display device for displaying an image in each of the video memories. 3. A high-resolution video camera, a first memory for storing an image output by the high-resolution video camera, a first memory for converting an image signal output by the high-resolution video camera into digital data, and writing the digital data in the memory. One memory writing circuit, a sync signal generating circuit that generates the same sync signal as a normal resolution camera, an area designating circuit that determines a read area of the memory based on the sync signal generated by the sync signal generating circuit, and the sync Receiving a synchronizing signal generated by the signal generating circuit and a region designating signal output by the region designating circuit, reading data of a region designated in the effective scanning period from the memory, converting the data into an analog signal, and superimposing the synchronizing signal. One memory reading circuit, generating an image pattern representing a designated area output from the area designating circuit, and reading the image pattern from the first memory reading circuit. From the output of the area designation signal superimposing circuit that outputs the output of the area designation signal superimposing circuit, the receiver that receives the output of the transmitter, the area designating signal superimposing circuit that superimposes and outputs the blanking period of the output signal of the circuit An area designation signal detection circuit that detects an image pattern corresponding to the area designation signal, converts the image pattern into an area designation signal, and outputs the area designation signal, a second memory,
A second memory writing circuit which receives an area designation signal and converts the image signal output from the receiver into digital data and writes the image signal in a corresponding area of the second memory according to a scanning pattern of the high resolution video camera. An image transmission device comprising a second memory readout circuit for reading out the contents of a second memory and converting it into an analog signal, and a high resolution display device for displaying a high definition image of the high resolution video camera. . 4. A high-resolution video camera, a first memory for storing an image output by the high-resolution video camera, a first memory for converting an image signal output by the high-resolution video camera into digital data, and writing the digital data in the memory. One memory writing circuit, a sync signal generating circuit for generating the same sync signal as a camera having a normal resolution, and a first reset-type area for determining a read area of the memory based on the sync signal generated by the sync signal generating circuit. A designated circuit, a first timer circuit that measures time and initializes the first reset-type area designation circuit at a determined time, a synchronization signal generated by the synchronization signal generation circuit, and the reset-type area designation circuit. Upon receiving the area designation signal to be output, the data of the area designated in the effective scanning period is read from the memory and converted into an analog signal, and the synchronization signal is output. A first memory read circuit that is superposed,
A transmitter for transmitting the output of the memory read circuit, a receiver for receiving the output of the transmitter, a sync signal separation circuit for separating a sync signal from the output of the receiver, a second reset type area designation circuit, the second A second timer circuit for initializing the reset type area designation circuit at a predetermined time, a second memory, and a second memory circuit for receiving the area designation signal output from the second reset type area designation circuit. A second memory writing circuit that converts the image signal output from the receiver into digital data and writes it in a corresponding area, and reads the content of the second memory according to the scanning pattern of the high resolution video camera and converts it into an analog signal. An image transmission device comprising: a second memory readout circuit for controlling the high resolution video camera; and a high resolution display device for displaying a high definition image of the high resolution video camera.