JPH01117489A - Stational picture visual telepone communication system - Google Patents

Abstract

PURPOSE: To minimize call interruption time by directly transmitting/receiving still picture data without executing handshaking in the case of sending specific standardized still picture data. CONSTITUTION: When a simple procedure switch 19 is turned on, a CPU 11 automatically selects a previously determined 96×96 pixel mode, a telecamera 14 supplies one picture to a picture memory 16 and the CPU 11 switches a mode from a talking mode to a picture mode. A sheet of picture information stored in the memory 16 is sent to the receiving side from a telephone line terminal 8 through a picture transmission system. Immediately after the completion of transmission, the picture mode is retured to the talking mode and the system is returned to a general talking state. Thus handshaking can be omitted by turning on the switch 19. Consequently a still picture can be transmitted within a short time and call interruption time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a still image videophone communication system, and particularly to an improvement in a transmission/reception/borrowing connection system during still image data communication.

[Prior Art] There is a demand for a videophone that transmits audio and images simultaneously using a telephone communication line, but in reality, current telephone communication lines cannot continuously transmit dynamic images that require a huge amount of data. Since it is difficult to send and receive a still image to the other party during a call, still image videophones are being put into practical use.

This still image videophone allows you to
The i-4 function is to temporarily interrupt this call and send a desired still image, such as the speaker's face, a photo screen or a picture depending on the content of the call, or the like.

Therefore, with such a still image videophone, it is possible to send and receive images over a telephone line, which was previously impossible, and the amount of data processing is limited because only one still image is sent each time. This had the advantage of making it possible to put videophones into practical use easily.

[Problems to be solved by the invention] However, in the conventional still image videophone communication system,
Since the systems of the telephones used at both the transmitting and receiving terminals are not necessarily the same, it is necessary to confirm the system types of the transmitting and receiving terminals each time transmission and reception are performed.

This kind of system type confirmation is performed by so-called handshaking, in which only headers (information) including ID data are exchanged in advance to confirm compatibility between devices at both ends before sending and receiving the necessary image data. was.

FIG. 5 shows a conventional still image videophone communication system, in which videophones at both ends are connected by an exchange and a call is made.

During this call, the telephone line (occasionally, the call is interrupted and switched to still image communication).

In conventional communication systems, an I
A header containing the D code is sent. Then, the receiving side confirms the sent ID code, and then returns an ID code indicating the system type of the receiving end.

Therefore, the video telephone on the transmitting side checks the ID code returned in this way and after determining that the system types at both ends match, it starts transmitting the predetermined image data. The sending and returning of the ID code in FIG. 5 indicates a handshake, and in the past, such an
Only the header containing the D code is used for handshaking.

The system type indicates, for example, the capability of the transmitter/receiver phone, that is, the pixel size of the transmitter/receiver screen, etc.
These pixels are 48X48.64X64.96X96.
It is divided into several types such as 128x128 drawings.

Therefore, if the number of pixels differs between the sending and receiving ends, a situation arises in which precious still image data cannot be sent to the receiving end, and in the past, handshaking by sending only the header containing the ID code and sending it back was not practical. was always required before sending and receiving image data.

Therefore, the conventional system has the drawback that the handshake requires a large amount of time, resulting in a long call interruption time.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide an improved still image videophone communication system that can shorten the communication time of still image data, that is, the call interruption time. It is in.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for directly transmitting and receiving still image data without handshaking when specific standardized still image data is sent. Features.

[Operation] Therefore, according to the present invention, during a call, predetermined still image data enters data communication immediately without performing a preliminary handshake, and as a result, the communication time of the still image data, that is, the call interruption time, is shortened. This makes it possible to use still image videophone communication most effectively.

[Example] Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows a schematic configuration of one of the transmitting and receiving ends of a still picture video telephone device to which the present invention is applied.

In the figure, a handset (1), a microphone (2), and a speaker (3) are connected to an audio input/output circuit (4).
Audio input/output during a call is controlled. This audio signal is then transferred to the analog circuit (5) and the matrix switch (
6) Then, it is sent to the telephone line connection terminal (8) via the telephone interface circuit (7), and similarly, the voice signal from the other party is sent to the handset (
1) or the speaker (3).

On the other hand, when communicating still image data, the keypad (
9) to send an image, the human output boat (1
0), the CPU (11) detects this and sends the image data to the modulation/demodulation circuit (13) according to a program stored in advance in the program memory (12).

After modulating this image data into an analog signal, it is sent to the telephone line from the telephone line connection terminal (8) via the matrix switch (6).

The image data from the communication partner passes through a path opposite to the above-mentioned signal path, and the CPU (11) checks the returned code and performs other checks. The image data is then captured by a television camera (14
), this image signal is quantized by the image controller (15), stored in the image memory 16, and sequentially derived and displayed on the display (17).
According to the command U (11), the image is output from the image memory to the telephone line connection terminal (8).

Further, when image data is input from the communication partner, the matrix switch (6) switches the received signal from the telephone interface circuit (7) from the analog circuit (5) to the modulation/demodulation circuit (13) according to the received carrier signal.

After the received 7R signal is demodulated by the modulation/demodulation circuit (13), the CPU (11) stores the data in the image memory (16), and the image controller (15) sequentially derives the self-image data and the other party's image data. Display (17
).

Note that when the transmission and reception of images is completed, the modulation/demodulation circuit (13)
The carrier signal from the matrix switch (
6) connects the telephone interface circuit (7) and analog circuit (5) to restore voice communication.

In the device of this embodiment, the keypad (9) includes a transmission switch (18) and a simple procedure switch (19), and communication is performed using the transmission switch (18) through normal handshake.
), and handshake-free communication, which is a feature of the present invention, is performed by turning on the simple procedure switch (19).

FIG. 1 shows an outline of the communication system according to the present invention, and unlike the conventional example shown in FIG. 5 described above, image data is transmitted without handshaking during a call using a telephone line.

Therefore, according to the present invention, it is possible to significantly reduce call interruptions due to image data transmission during a call.

FIG. 3 shows an example of image data suitable for the present invention, and this image data is shown in FIG.
an image data frame formed from one screen worth of electrical image data captured from 14) as a serial signal;
This image data frame is preceded by a header frame provided at its head. In the embodiment, the image data in FIG. 1 is sent as data in which the header frame and image data frame in FIG. 3 are concatenated, and on the receiving side, preparations for image creation are made using the header frame sent in advance.

As shown in FIG. 3, the header frame includes a data amount command L1 of image data to be sent, a pixel capacity M1 to be sent, frame information F including a handshake omission command if necessary, an ID extension command, and an error check bit. FC3, and in normal cases, the header information is almost the same as the ID command for confirming the sending/receiving time when handshaking is performed, but as mentioned above, the signal F containing the handshake omission command in the header frame is It is characterized by including.

Of course, in the present invention, any command may be used as the handshake omitting command in the header frame, but in reality, a bit command with handshake omitted is included in the header frame preceding the image data frame. It is preferable that

Furthermore, in the present invention, the handshake omission command within the header frame does not necessarily need to be added, and in this case, the header frame and image data frame can be directly subjected to image processing on the receiving side.

FIG. 4 shows the specific operation of the communication system according to the present invention, and in FIG. This switching is executed, and image transmission during a call is commanded by switching the transmission switch (18).

In FIG. 4, the telephone line is normally in a talking state, and during this talking, the switching of the transmission switch (18) is monitored. 11 - When it becomes necessary to transmit image data, the transmission switch is turned on, and the system in the embodiment determines whether this transmission command is normal communication with handshake or communication without handshake. Let's do it.

Generally, a handshake is performed to confirm the sending and receiving end due to differences in pixels and other system types between the sending and receiving sides, but in certain cases, it is possible to omit this handshaking. Become.

In the embodiment, such a handshake omitted state can be omitted, for example, for a transmission mode in which the pixels are 96×96, and in the embodiment as well, the handshake omitted state can be omitted for a transmission mode in which the pixels are 96×96.
When 6 is selected, the simple procedure switch (19) in the keypad (9) is turned on, and handshake omitted communication is started.

The 96x96 pixel mode is the mode that most commonly used still image videophones have, and as a result, data communication is possible without handshaking in most cases during this specific save transmission. The present invention focuses on this point and uses a common communication mode that is easy to standardize.
6, communication without handshake is performed.

When the simple procedure switch (19) is in the OFF state, communication with handshaking similar to the conventional one shown in FIG. 5 is performed, but on the other hand, when the switch (19) is turned on, If so, a predetermined image is first selected. In the example, this image shows a pixel 96x96 mode, and in the example, the CPU
(11) automatically selects this pixel 96×96 mode.

When preparations on the sending side are completed in this way, the television camera (14) supplies one screen to the image memory (16), and the CPU (11) switches from the call mode to the image mode.

The image information stored in the image memory (16) passes through the above-mentioned image transmission system to the telephone line terminal (8).
) is sent to the receiving side. This image communication is constantly monitored until its end, and as soon as the transmission ends, the image mode returns to the talk mode, and then returns to the intra-diameter talk mode.

As described above, according to the present invention, handshaking is omitted by turning on the simple procedure switch, and as a result, still images can be transmitted in an extremely short time.
This has the effect of reducing call interruption time.

And, according to the invention, such a handshake omission mode is implemented in accordance with a particular embodiment of pixel 96
mode, so most terminal telephones can receive this without handshaking, ensuring both reliable data communication and shortened communication time.

Of course, in the present invention, the common mode is pixel 96X
96, but also any particular system type common to the terminal telephones.

In the above-described embodiment, the command to omit the handshake is issued by a simple procedure switch, but in the present invention, when a preselected specific system type for handshake saving is selected, the command to omit the handshake is automatically issued. can be configured to perform handshake-skip mode communication, thereby omitting the shortcut switch and
The configuration and operation can be simplified.

[Effects] As described above, according to the present invention, handshaking can be omitted in a specific system type transmission mode, and the transmission time and call interruption time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a schematic configuration of a communication method according to the present invention, FIG. 2 is a block circuit diagram of a still image videophone device in which the communication method of the present invention is used, and FIG. 3 is an image suitable for the present invention. FIG. 4 is a flowchart showing the communication method of the present invention, and FIG. 5 is an explanatory diagram of the conventional communication method including handshake. In the figure, (9) is a keypad,
(18) indicates a transmission switch, and (19) indicates a simple procedure switch. Agent Patent Attorney Masuo Oiwa (and 2 others) Figure 1 #1 Female Figure 3 Figure 4

Claims (1)

[Claims] (1) In a still image videophone communication system that uses a telephone communication line to send and receive desired still images during a call, for certain system types, still image data is transmitted without handshaking between sending and receiving. A still image videophone communication method characterized in that communication is started.