JPH04344787A - Visual telephone - Google Patents

Abstract

PURPOSE:To prevent a picture different from an actual reception picture from being displayed at talking start. CONSTITUTION:A coding picture signal from an opposite party is inputted to a picture decoding section 13 via a line interface 10 from a line and decoded and stored in a display picture memory 14. A picture data read from the display picture memory 14 is inputted to a TV signal processing section 17 via a display picture changeover switch 15, processed by a display signal and displayed on a monitor 8. While decoding by a picture decoding section 13 is finished after the start of talking, a control section 20 mutes the TV signal processing section 17 by using a control signal 34 or clears a display picture memory 14 by using a control signal 32 to attain muting, and when the display of a transmission picture or the display of a character message is set, the display picture changeover switch 15 is switched to display a transmission picture of its own station or a character message from a character generating section 16 thereby controlling the picture of the display picture memory 14 so as not to be displayed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video telephone device capable of transmitting and receiving both images and sounds.

0002

[Prior Art] Generally, in this type of video telephone device,
The transmitting side sends out an audio signal, compresses and encodes an image signal, and transmits it, and the receiving side plays back the received audio signal, decodes the received encoded image signal, stores it in the image memory, and transfers the image from the image memory. It is configured to read and display data.

Conventionally, when displaying a received image, this type of video telephone device is configured to read image data from an image memory and display it immediately after a line is established.

0004

[Problems to be Solved by the Invention] However, in the conventional videophone device described above, after the power is turned on, if the received image has not arrived or if it takes a long time to decode the received image, the line cannot be established. If the image data is immediately read out from the image memory and displayed, for example, the received image from the previous call will be read out and a different image than the actual received image will be displayed at the start of the call, giving the user a sense of discomfort. There is a point.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a video telephone device that can prevent an image different from an actual received image from being displayed at the start of a call.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a storage means for storing received images, a display means for displaying received images, and a first received image after the start of a call. The apparatus is characterized by comprising a control means for controlling the received image stored in the storage means not to be displayed on the display means until reception is completed.

[0007]

[Function] With the above configuration, the present invention prevents the display of an image different from the actual received image at the start of a call by reading out the received image from the previous call from the storage means and not displaying it at the start of the call. It can be prevented.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the video phone device according to the present invention, and FIG. 2 is a timing chart for explaining the operation of the video phone device of FIG. 1 during reception.

In FIG. 1, a transmitted image is captured by a camera 1, and an image signal captured by the camera 1 is transmitted to a TV.
The signals are processed into component signals by the signal processing unit 2 and temporarily stored in the image memory 3. The image data read from the image memory 3 is subjected to intraframe encoding and interframe encoding by the compression encoding unit 4, and is sent to the line via the line interface 10. In addition, the transmitted audio is
It is converted into an analog audio signal by the microphone 5, encoded by the audio encoder 6, and sent to the line interface 1.
0 to the line. The signal processed by the TV signal processing unit 2 is output to a display image changeover switch (SW) 15, which will be described later.

On the other hand, the encoded audio signal from the other party is sent from the line to the audio decoder 11 via the line interface 10.
is decoded into an analog audio signal and sent to speaker 1.
2 is reproduced. Further, the encoded image signal from the other party is inputted from the line to the image decoding unit 13 via the line interface 10, decoded, and sent to the display image memory 14.
is stored in The image data read out from the display image memory 14 is transferred to a display image changeover switch (SW) 15.
The signal is input to the TV signal processing unit 17 via the TV signal processing unit 17, processed into a display signal, and displayed on the monitor 18.

The character generating section 16 generates characters for displaying a message such as "receiving", and these characters are sent to the TV via a display image changeover switch (SW) 15.
The signal is input to the signal processing section 17 and processed into a display signal, which is displayed on the monitor 8.

[0012] The control unit 20 controls the entire TV telephone device, and in particular instructs the line interface 10 to start and end a call, and performs data reception, decoding completion, etc. with the image decoding unit 13. It exchanges control signals 31, controls writing and reading of display image memory 14 using control signals 32, instructs character generation section 16 to generate characters using control signals 32, and controls TV signal processing section 17. The processing is controlled by a control signal 34. The input section 21 is composed of a dial key, a hook switch, a display image switching key at the time of reception, etc., and the control section 20 performs various controls according to the operation of the input section 21.

In the above configuration, when transmitting, when the hook switch of the input section 21 is off-hook, the control section 20 switches the line interface 10 to close the line.
Then, when the dial number of the other party is entered using the dial key of the input unit 21, the line interface 10 is controlled so as to send a dial signal to the line.

Next, the reception operation of the above embodiment will be explained with reference to FIG. When a call arrives at the line interface 10 and the hook switch of the input section 21 is turned off, the line is established and a call is started. The encoded audio data is
Since the compression rate is low, it is decoded in a short time by the audio decoding section 11 and converted into audio by the speaker 12. On the other hand, when displaying the received image, if the mute state is set by the display image switching key of the input section 21, the control section 20
For example, the TV signal processing unit 17 is put into a mute state by the control signal 34.

Therefore, when the encoding time of the image on the transmitting side is long and the first received image has not arrived, or when the compression rate of the encoded image data is high and the decoding time is long, the display image memory 14 is Since image data is not displayed, for example, the received image from the previous call will not be read out and an image different from the actual received image will not be displayed at the start of the call, and therefore the user will not feel uncomfortable.

Note that until the decoding by the image decoding section 13 is completed, instead of putting the TV signal processing section 17 into the mute state by the control signal 34, the display image memory 14 is cleared by the control signal 32 and the TV signal processing section 17 is put into the mute state. Also, if the display of the transmitted image or text message is set, the transmitted image of the own station whose display image changeover switch 15 is switched or the text message from the character generator 16 may be displayed. do.

[0017]

Effects of the Invention As explained above, the present invention provides a storage means for storing the first received image, a display means for displaying the received image, and a storage means for storing the first received image. and control means for controlling the received image stored in the storage means not to be displayed by the display means during the call period, so that at the start of a call, for example, the received image from the previous call is read out from the storage means and displayed. Therefore, it is possible to prevent an image different from an actual received image from being displayed at the start of a call.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a video telephone device according to the present invention.

FIG. 2 is a timing chart for explaining the operation of the video telephone device of FIG. 1 during reception.

[Explanation of symbols]

13 Image decoding unit 14 Display image memory 15 Display image changeover switch (SW) 17 T
V signal processing section 19 Monitor 20 Control section 21 Input section

Claims (4)

[Claims] 1. A storage means for storing a received image; a display means for displaying a received image; and control means for controlling the received image not to be displayed on the display means. 2. The videophone apparatus according to claim 1, wherein the control means mutes the screen of the display means until reception of the first received image is completed after the start of the call. 3. The control means controls the transmitted image to be displayed on the display means until the reception of the first received image is completed after the start of the call. Videophone device. 4. The control means controls the display means to display a text message to that effect until the reception of the first received image is completed after the start of the call. 1. The videophone device according to 1.