JPS6214156B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a still image transmission device having image memories on each of the transmitting side and the receiving side.

A conventional still image transmission device stores one frame of image signal obtained from a television camera in a transmitting image memory, reproduces and transmits it, stores it in a receiving image memory, reproduces it, and displays it on a monitor. be. That is, FIG. 1 is a block diagram showing a conventional still image transmission device. In the same figure,
1 is a television camera; 2 is an A/D converter that converts an image signal obtained from the television camera 1 into a digital signal; 3 is a transmission image memory that stores this digital signal; and 4 is a transmission image memory 3. A transmission line for transmitting the reproduced digital signal; 5 is a reception image memory for receiving and storing the digital signal sent via the transmission line 4; 6 is for converting the reproduced digital signal from the reception image memory 5 into analog form. D/A to convert into signal
Converter, 7 is a monitor.

Next, the operation of the still image transmission device having the above configuration will be explained.

First, an image signal obtained from a television camera 1 is converted into a digital signal by an A/D converter 2 and stored in a transmission image memory 3. The digital signal reproduced from the transmission image memory 3 is then transmitted to the transmission line 4. The digital signal sent through the transmission line 4 is then stored in the reception image memory 5.
to be memorized. The digital signal reproduced from the received image memory 5 is converted into an analog signal by a D/A converter 6 and then displayed on a monitor 7. By looking at the image displayed on the monitor 7, it was determined whether there was an error in the image memory.

However, with conventional still image transmission equipment, even if there is an error in the image displayed on the monitor, it is not possible to determine whether the error is due to the transmitting image memory or the receiving image memory, and it is difficult to measure each image memory. However, there was a drawback that errors had to be detected.

Therefore, it is an object of the present invention to easily identify whether a failure is in the transmitting image memory or the receiving image memory by utilizing the fact that failures in the transmitting image memory or receiving image memory in a still image transmission device occur in a fixed manner. The purpose of the present invention is to provide a still image transmission device that can make a decision.

In order to achieve such an object, the present invention makes the polarities of the image signals stored in the transmitting image memory and the receiving image memory opposite to each other when viewed from the receiving monitor. This system is designed so that it can be determined whether the transmitting image memory or the receiving image memory is at fault based on the error caused by the error, and will be explained in detail below using an example.

FIG. 2 is a block diagram showing an embodiment of a still image transmission device according to the present invention. In the same figure, 8
A first polarity inverter 9 inverts the polarity of the digital signal reproduced from the transmission image memory 3, and a second polarity inverter 9 inverts the polarity of the digital signal reproduced from the reception image memory 5.

Next, the operation of the still image transmission device having the above configuration will be explained.

First, an image signal obtained from the television camera 1 is converted into a digital signal by the A/D converter 2 and stored in the transmission image memory 3. The digital signal reproduced from the transmission image memory 3 is transmitted to the transmission line 4 after its polarity is inverted by the first polarity inverter 8. The digital signal sent through the transmission line 4 is stored in the received image memory 5. The polarity of the digital signal reproduced from the received image memory 5 is inverted by a second polarity inverter 9, and then converted into an analog signal by a D/A converter 6. This analog signal is then displayed on the monitor 7.
Here, since a failure in the transmission image memory 3 or the reception image memory 5 generally occurs in the direction in which the readout signal becomes non-signal, the failure occurs in the direction in which the readout signal becomes constant. Therefore, when recording in the sending image memory 3 and receiving image memory 5,
If the polarities are reversed when viewed from the image receiving monitor, when the images are reproduced on the monitor 7, the image reproduced from the faulty image memory will be displayed with reverse polarity. That is,
If one is a white dot, the other is displayed as a black dot. Therefore, by looking at this white dot or black dot on the monitor, it can be easily determined whether the transmitting image memory 3 or the receiving image memory 5 is at fault.

As described in detail above, according to the still image transmission device according to the present invention, it is possible to easily determine whether the transmitting image memory or the receiving image memory has failed by viewing the image displayed on the monitor. There is an effect that can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional still picture transmission device, and FIG. 2 is a block diagram showing an embodiment of the still picture transmission device according to the present invention. 1... Television camera, 2... A/D converter, 3... Transmission image memory, 4... Transmission line, 5
...Reception image memory, 6...D/A converter, 7...
...Monitor, 8...First polarity inverter, 9...Second polarity inverter.

Claims (1)

[Claims] 1 The image signal of one scanned frame is converted into a digital signal by an A/D converter, then stored in a transmission image memory, and the image signal obtained by reproduction is transmitted to the receiving side via a transmission line and received. In a still image transmission device that stores an image signal in a received image memory, converts the reproduced digital signal into an analog signal using a D/A converter, and displays it on a monitor, the image signal obtained by reproducing it from the transmitted image memory is A still image transmission device comprising: a first polarity inverter that inverts the polarity; and a second polarity inverter that inverts the polarity of an image signal obtained by reproducing from a received image memory.