JPH01117490A - Stational picture visual telephone transmission system - Google Patents

Abstract

PURPOSE: To control required response time by setting up required response waiting time data in an ID code at the time of handshaking and delaying succeeding response processing only for time corresponding to the received response waiting time. CONSTITUTION: Response waiting time data T corresponding to initial eight bits which are idle data at conventional handshaking are generated in an ID code at the time of handshaking. Namely the ID code of the opposite party is received at the time of handshaking, response waiting time data T are read out, and after judging the waiting time, starts the counting of waiting time. After the lapse of the waiting time, corresponding response processing such as the sending of an ID code or picture data is executed. Since unnecessary waiting time can be cut out and the response sending of the opposite party can be delayed only for required time when a receiving system is not established yet, accurate picture transmission can be attained.

Description

[Detailed Description of the Invention] [Industrial Application Fields] The present invention relates to a still image videophone transmission system, in particular, a still image image signal captured by a camera installed in a telephone set, which is modulated into an audio band signal. The present invention relates to an improvement in a still image videophone transmission system in which the image signal is sent to a telephone line, and the image signal supplied from the telephone line is demodulated and visualized on a display.

[Prior Art] Hereinafter, a simple still picture videophone using a conventional still picture videophone transmission system will be explained based on the drawings.

Figure m4 is a circuit configuration diagram of a simple still image video telephone set shown in, for example, the October 1986 issue of Foreign Communication Technology.

In the figure, (1) is a handset, (2) is a microphone, (3) is an audio input/output circuit, (4) is an analog circuit, (
5) is a matrix switch, (6) is a telephone interface circuit, (7) is a telephone line connection terminal, (8) is a speaker, (9) is a keypad, (10) is an input/output board, (1)
1) is the CPU, (12) is the program memory, (13)
is a modulation/demodulation circuit, (14) is a television camera, (15) is an image controller, (16) is an image memory, (17)
is the display. Further, FIG. 4 is a sequence diagram showing an image transmission procedure of the video telephone.

Next, the operation of audio and image signal transmission in the conventional video telephone will be explained with reference to FIGS. 4 and 5. In Figure 4, voice calls are made using the handset (1) or the microphone (2).
) to audio input/output circuit (3), analog circuit (4), matrix switch (5), telephone interface circuit (
6) and is sent to the telephone line connection terminal (7). Further, an audio signal from the other party is reproduced by the handset (1) or the speaker (8) via a path opposite to the above-mentioned signal path.

On the other hand, when transmitting an image signal, a handshake as shown in FIG. 5 is performed and a still image is transmitted.

In other words, identification code data (hereinafter referred to as ID code) indicating the capability of the device is sent to confirm whether the communication partner is a videophone with the same data format, and after confirming that the ID code has been returned from the other party, image data is transmitted. Send.

Here, FIG. 6(a) shows the ID code at the time of handshake, and FIG. 6(b) shows the ID code at the time of image data transmission.
Code is shown.

As shown in FIG. 6(a), I during handshake
The first 8 bits of the D code are 0 data, followed by machine data (M) indicating the function of the telephone, frame type data (F) indicating the frame type such as the number of pixels of the frame to be transmitted, and ID extension indicating that the ID code follows. code data and
It consists of frame check sequence data (FCS).

Furthermore, as shown in Figure 6(b), the ID code when transmitting image data includes length data (L) indicating the amount of data per line, which is generated in the first 8 bits, and frame type data (F). The frame type of image data that is actually transmitted is generated based on the consistency of the functions of both devices that perform transmission and reception, and the data configurations in both ID codes are the same.

Therefore, in FIG. 4, when the keypad (9) is used to instruct image transmission, the input/output port (10)
The PU (11) detects this and stores the program memory (1
2) sends the ID code to the modulation/demodulation circuit (13) according to a program stored in advance. After modulating this ID code into an analog signal, a matrix switch (
5) from the telephone line connection terminal (7). The ID code from the communication partner passes through a path opposite to the above signal path, and the CPU (11) confirms the code. During this time, the image captured by the television camera (14) is quantized by the image controller (15), stored in the image memory (16), sequentially derived and displayed on the display (17), and then processed by the CPU.
In response to the command (11), the image is output from the image memory (16) to the telephone line connection terminal (7).

Also, when an ID code or image data is input from the other party, the matrix switch (5) uses the carrier signal received to send the destination to the telephone interface circuit (6).
The received signal from the analog circuit (4) is transferred from the modulation/demodulation circuit (
Switch to 13).

After the received signal is demodulated by the modulation/demodulation circuit (13), the CPU (11) returns the ID code or stores the data in the image memory (16), and the image controller (15) sends the self-image data and the other party's image data. are sequentially derived and displayed on the display (17).

Note that when the transmission and reception of images is completed and the carrier signal from the modulation/demodulation circuit (13) disappears, the matrix switch (5
) is the telephone interface circuit (6) and the analog circuit (4).
) to restore voice calls.

The conventional ID code or image data response is
As shown in FIG. 5, this is done after waiting for one second after receiving the other party's ID code.

In other words, conventional videophones are configured to match the impedance of the line and the telephone when an image transmission instruction is input, so one second of response waiting time is required in order to accurately receive data. , and the response was automatically delayed for 1 second.

[Problems to be solved by the invention] Since this method is performed in a manner better than the conventional still image videophone transmission method, a waiting time of 1 second is unnecessary when transmitting with a model that does not perform impedance matching. There was a problem.

Another problem is that there are cases where a waiting time of one second or more is required, such as when the reception system is not ready.

This invention was made to solve the above-mentioned problems, and it generates a code specifying a desired response waiting time in the ID code at the time of handshake, and responds for a time corresponding to the received response waiting time. The purpose of the present invention is to obtain a still image videophone transmission system that can delay the transmission of images.

[Means for Solving the Problems] In order to achieve the above object, the still image videophone transmission system according to the present invention generates a code specifying a desired response waiting time in the ID code at the time of handshake, Received ID
The present invention is characterized in that the response to ID code transmission, image data transmission, etc. is delayed by a time corresponding to the code response waiting time.

[Function] According to the still image videophone transmission system of the present invention, it is possible to eliminate the unnecessary waiting time of the conventional method, and at the same time, when the reception system is not ready, it is possible to delay sending a response from the other party by the necessary time. Therefore, accurate image transmission can be performed.

[Embodiment] Hereinafter, an embodiment of the still picture videophone transmission system according to the present invention will be described with reference to the drawings.

Figure 1 shows I during handshake according to the method of the present invention.
This is a configuration diagram of the D code, and as shown in the figure, in this embodiment, response waiting time data (T) is generated in the first 8 bits, which were empty data during the conventional handshake.

At this time, for compatibility with the conventional model, the response waiting time data (T) is set to be 1 second when "oooooooo".

Next, processing of waiting time will be explained based on FIG.

First, during handshake, the other party's ID code is received and response waiting time data (T) is read.

Then, the waiting time is determined from the read response waiting time data (T) and counting of the waiting time is started.

After the waiting time has elapsed, corresponding response processing such as sending an ID code or image data is performed.

Therefore, a sequence diagram showing the image transmission procedure of the still picture video telephone according to this embodiment is shown in FIG.

FIG. 3(a) shows the response waiting time data (T
) shows the case when T-0, and FIG. 3(b) shows the case when the response waiting time data (T) of both electric transmitters is T-5.

Therefore, according to this embodiment, response waiting time data (T) is generated in the first 8 bits that are empty data during conventional handshaking, so the response waiting time instruction can be set using the same specifications as the conventional ID code. It has the effect of being able to.

Further, in this embodiment, the response waiting time data (T) is '
ooooooooo", it is set to 1 second, and when an ID code is received from a conventional model, the response processing is delayed by 1 second, so it is compatible with the conventional model.

[Effects of the Invention] As explained above, according to the still image videophone transmission system according to the present invention, desired response waiting time data is set in the ID code at the time of handshake, and data corresponding to the received response waiting time is set. Since the next response process is delayed by the amount of time, it is possible to control the response time to the required time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of an ID code according to an embodiment of the static 11-picture videophone transmission system according to the present invention, FIG. 2 is a flowchart of waiting time processing according to the embodiment of FIG. 1, and FIG. FIG. 1 is a sequence diagram showing the image transmission procedure of the still image video phone according to the embodiment; FIG. 4 is a configuration diagram of the conventional still image video phone; FIG. 5 is a sequence diagram showing the image transmission procedure of the still image video phone; FIG. 6 is a diagram showing the structure of an ID code according to an embodiment of the conventional still picture videophone transmission system. In the figure, (7) is a telephone line terminal, (13) is a modem circuit, (17) is a display, (18) is a carrier detection circuit, (19) is a line changeover switch, (20) is a telephone connection terminal, and (11) is a telephone line terminal. ) is the CPU. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Patent attorney Masuo Oiwa (and 2 others) Figure 1 Figure 2 Figure 3 oo NF Figure 5 Video phone Switchboard Video phone Figure 6

Claims (1)

[Claims] (1) Prior to still image transmission, identification code data indicating the phone's functions, such as the number of divided pixels per still image frame, is sent and received to check the compatibility of the phone's own device's functions with those of the other party's device. In a still image videophone transmission method that transmits and receives still images via a telephone line, the method includes a handshake step for determining whether or not to transmit still images, and generates desired response waiting time data in the identification code data. and, during the handshake step, the sending of response data such as identification code data or still image data is delayed by a time corresponding to response waiting time data in the received partner identification code data. Telephone transmission method.