JPH0771272B2 - Still image videophone - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a still image videophone device capable of transferring a still image during a call, and more particularly to a configuration capable of transferring bit data such as character information.

[Prior Art] With recent advances in semiconductor technology and digital image processing technology, videophones that transmit and receive still images through analog telephone lines have become a reality.

As an example of such a still image videophone device, the one shown in the October 1986 issue of Foreign Communication Technology will be described with reference to FIGS. 6 to 8.

In the figure, (1) is a telephone line, (2) is a monitor TV displaying a self image and a partner image, (3) is a TV camera, (4) is a handset for a call, and (5) is selection such as dialing. Numeric keypad for signal input, (6)
Is a send button for instructing the other party to send a still image, (7) is a telephone interface section for connecting to the line, (8) is a communication circuit including an amplifier for calling, and (9) is still image data. A modulation / demodulation unit that performs modulation and demodulation for placing on the telephone line, (10) a switch unit that switches signal connection with the line between the communication circuit (8) and the modulation / demodulation unit (9), and (11) a television for transmission. An image storage unit that stores images captured by the camera (3) as still image data and also stores still image data from a communication partner, and (12) is a television camera (3).
A / D conversion of the video signal from is converted to still image data, and the signal from the image storage section (11) is D / A converted to a video signal, as well as the creation of synchronization signals, writing / reading processing of image storage, etc. An image control processor unit (13) is a central processing unit composed of a microcomputer and including a ROM and a RAM.

Next, the operation of this device will be described. Pick up the handset (4), dial with the ten-key (5), connect the telephone line with the other party, and establish communication. At this time, the switch unit (10) is in a voice communication state, that is, a call state. Therefore, the signal of the telephone line (1) is transmitted and received via the communication circuit (8). An image taken by the television camera (3) is displayed on the right side of the screen of the monitor television (2) via the image control processor (12).

When sending a still image to the other party in this state, the send button (6) is pressed. Then, the depression of the send button is detected by the central processing unit (13). The central processing unit (13) drives the image control processor (12) to store the image data from the camera (3) for one field in the image storage unit (11). Further, pixel data is sequentially taken out from the image storage section (11) and a signal is given to the modulation / demodulation section (9). The switch section (10) is switched to the modulation / demodulation section (9) side by pressing the transmission button, and the modulated signal is transmitted to the telephone line (1). When the transmission of the pixel data for one field is completed, the central processing unit (13) switches the switch unit (10) to the original call side.

Next, the still image reception from the other party is demodulated by the modulation / demodulation unit (9), sequentially stored in the image storage unit (11) via the image control processor, and displayed on the left side of the screen of the monitor television (2). .

The image data in this conventional example is modulated into an image signal as follows. In other words, in the example shown in FIG. 8, the phase is the sin curve type first phase and this is 1
There is a −sin type second phase having a phase difference of 80 degrees, and each phase is formed by signals having a plurality of amplitudes. And
The signal of one cycle having a specific phase and a specific amplitude is associated with a specific color. In this example, each phase has 8 cycles, and there are 16 cycles in total. The maximum amplitude signal “15” of the first phase corresponds to white and the maximum amplitude signal “0” of the second phase corresponds to black. And the intermediate signals "14" to "1"
There is a gray corresponding to each lightness.

[Problems to be Solved by the Invention] In such a conventional still image videophone apparatus, a voice call and a still image transmission / reception at an appropriate timing can be performed. However, it did not have the function of sending and receiving bit data such as character information. For this reason, there is a problem that another independent and large-scale device is required to transmit and receive the bit data.

The present invention has been made to solve the above problems, and by maximizing the use of the still image data transmission / reception function, it is very effective to add characters with a simple configuration. It is an object of the present invention to provide a still image videophone device that can also send and receive bit data such as information.

[Means for Solving Problems] A still image videophone device according to the present invention interrupts a call during a call and performs amplitude and phase modulation on image data obtained by a video camera for each predetermined pixel. , Generating an image data signal including information of three or more gradations for each pixel,
In a still image videophone device that transmits the generated image data signal to the other party through a telephone line, bit data that consists of binary data for each bit and that specifies character data such as character data by a plurality of bits is input. And a signal obtained by continuing a plurality of signals of two gradations selected in advance from the image data signals of three gradations or more, respectively corresponding to the binary value of each bit of the bit data.
Means for generating a bit signal from input bit data, and transmitting the bit signal using a signal in which a plurality of image data signals are continued.

[Operation] During a call, an image obtained by the television camera is modulated into an image data signal and transmitted. The image data signal sent from the other party is demodulated into image data and displayed on the monitor television.

Here, this device can also send and receive bit data. That is, the bit data is modulated into an appropriate signal selected from the above image data signals and transmitted as a bit signal. For this reason, the bit data can be modulated by the same modulation means as the image data, and the overall configuration is very simple, and the bit data is transmitted and received. Furthermore, since the bit signal is a continuation of a plurality of pixel data signals, reliable transmission / reception of bit data is achieved.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, (1) to (12) are the same constituent elements as those of the conventional still image videophone device shown in FIGS. 6 and 7, and the description thereof will be omitted.

The central processing unit (14) has the same function as the central processing unit (13) in the conventional example, but this central processing unit (14)
Also has a character generator function. That is, bit data of "0" and "1" and character data such as character information can be converted.
(15) is a character data transmission key for instructing transmission of character data, and (16) is a full keyboard for inputting character data.

Then, character data such as character information is performed from the full keyboard (16), and the input character data is transmitted by pressing the character data transmission key 15.

Here, the modulation / demodulation of character data in the central processing unit (14) and the modulation / demodulation unit (9) in this embodiment will be described.

First, the bit data “1” and “0” correspond to the signals in FIG. 8, respectively. As shown in FIG.
"1" corresponds to a signal in which the maximum amplitude signal of the first phase continues for 3 cycles, and "bit 0" corresponds to a signal in which the maximum amplitude signal of the second phase continues for 3 cycles.

Then, in the central processing unit (14) according to the flowchart of FIG. 4, the bit data is made to correspond to the bit signal, and this bit signal is output from the modulation / demodulation unit (9).

When entering characters such as text information from the full keyboard (16), enable the full keyboard (16). It should be noted that this may be linked to the picking up of the handset (4), or a switch may be provided separately. When the key of the full keyboard (16) is depressed, the code corresponding to this key is supplied to the central processing unit (14). The central processing unit (14) stores this code in a built-in memory, converts it into a display character which is, for example, a character, and displays it on the screen of the monitor television (2).

When this input work is repeated and the input work from the full keyboard (16) is completed, the character data transmission key (1
5) Press. A central processing unit (14) converts the input character data (character data in this case) into bit data. For example, one character is converted into 4-bit serial data. Then, the central processing unit (14) sends an instruction to transfer the bit data of "0" and "1" to the bit signal as described above to the modulation / demodulation unit (9), and the modulation / demodulation unit (9) outputs this bit signal. Is output. That is, if the bit data is "1", the fifteenth signal in FIG. 3 (a signal meaning "white" in the case of an image signal) is output, and if the bit data is "0", the third signal is output. The 0th signal in the figure (a signal meaning "black" in the case of an image signal) is output. Then, this is sequentially repeated for the input character data, and the character data is output as a bit signal. This bit signal is transmitted to the other party through the telephone line (1) as in the case of transmitting the image signal.

Next, the operation when a signal for the character data, that is, a bit signal is sent will be described with reference to FIG.

The bit signal sent through the telephone line (1) is demodulated by the modulation / demodulation unit (9) and taken in as data by the central processing unit (14). The central processing unit (14) determines whether the signal is the signal with the maximum amplitude of the first phase (15th signal) or the signal with the maximum amplitude of the second phase (0th signal). If three or more bits are included, it is determined that the bit data is "1" or "0".

Then, the central processing unit (14) converts the bit data into character data, stores it in the built-in memory, outputs it to the monitor television (2), and displays it here.

As described above, in the still picture videophone apparatus of this embodiment, the bit data is made to correspond to the image signal of FIG. 8 as shown in FIG. Therefore, the signal transmission / reception mechanism can also be used, and the overall configuration can be simplified. Further, since the signal having the maximum amplitude is used, the certainty of signal determination is high. Further, the bit signal is transmitted as three consecutive signals as shown in FIG. 3, and the receiving side determines whether two of the three signals can be confirmed. Therefore, even if one signal cannot be confirmed due to noise or the like, accurate determination can be performed, and overall reliability of signal transmission / reception is extremely high.

[Effects of the Invention] As described above, according to the present invention, since the bit data corresponds to the continuous signal selected from the image signals, the still image videophone is simple in its overall structure. In, effective bit data communication can be performed.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of a still picture videophone apparatus according to the present invention, FIG. 2 is a block diagram showing a circuit of the embodiment, and FIG. 3 is bit data and bit signals of the embodiment. FIG. 4 is a waveform diagram showing a procedure of bit data transmission, FIG. 5 is a flowchart diagram showing a procedure of bit data reception, and FIG. 6 is an example of a conventional still image videophone device. FIG. 7 is a schematic front view, FIG. 7 is a block diagram showing the circuit of the conventional example, and FIG. 8 is a waveform diagram for explaining correspondence of signals at the time of modulating image data. (1) is a telephone line, (2) is a monitor TV, (3) is a TV camera, (6) is a send button, (9) is a modulator / demodulator,
(14) is a central processing unit, (15) is a character data transmission key, and (16) is a full keyboard. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Lawrence DeEmmons, USA 95945 Rat Valley Snake Road, Grass Valley City, CA 15351 (72) Inventor James Scott McRae, USA 95949 Grass Valley City, Dugans Road, California 17095

Claims (2)

[Claims] 1. A call is interrupted during a call, and image data obtained by a television camera is amplitude- and phase-modulated for each predetermined pixel, and an image data signal including information of three or more gradations is provided for each pixel. In a still image videophone device that generates and transmits the generated image data signal to the other party through a telephone line, bit data that consists of binary data for each bit and that specifies character data such as character data by multiple bits And a signal obtained by continuing a plurality of signals of two gradations selected in advance from the image data signals of three or more gradations are input corresponding to the binary value of each bit of the bit data. Means for generating a bit signal from incoming bit data, and transmitting the bit signal using a signal in which a plurality of image data signals are continued. Still image videophone device to be collected. 2. The apparatus according to claim 1, wherein the image data signals of two gradations corresponding to each bit of the bit data are signals of maximum amplitude of two kinds of phases. Still picture videophone device.