Image transmission system
First Claim
1. A video phone comprising:
- input means for sequentially entering image data;
digitizing means for digitizing said input image data into digital image data;
memory means for sequentially storing said digital image data;
image signal producing means for producing an output image signal based on said digital image data sequentially read out from said memory means;
display means for sequentially displaying an image described by said output image signal;
compression and expansion means for compressing said digital image data read out from said memory means into compressed image data in an image transmitting mode and for expanding compressed image data into digital image data in an image receiving mode;
telephone means having telephone functions for transmitting and receiving a call;
line control means coupled to a public analog telephone line for selectively coupling one of said compression and expansion means and said telephone means to said public analog telephone line, said line control means including modem means for modulating said compressed image data from said compression and expansion means into a voice frequency signal in the image transmitting mode and for demodulating a voice frequency signal received through said public analog telephone line into compressed image data in the image receiving mode; and
control means for controlling at least said memory means and said compression and expansion means,said control means having means for freezing the image displayed on said display means at an arbitrary time by stopping the sequential storage of said digital image data into said memory means so that said compressed image data related to a frozen image is read out from said memory means and supplied simultaneously to said image signal producing means and said compression and expansion means in the image transmitting mode,said control means controlling said memory means and said compression and expansion means in the image receiving mode so that said compressed image data related to said voice frequency signal received through said public analog telephone line is first stored in said memory means and read out therefrom to be expanded in said compression and expansion means into digital image data which is then stored in said memory means, said digital image data being read out from said memory means to be supplied to said image signal producing means.
1 Assignment
0 Petitions
Accused Products
Abstract
A video phone comprising an input device for entering input image data to be transmitted, a circuit for digitizing the input image data into digital image data, a memory for storing the digital image data, a first circuit for producing an output image signal based on the digital image data from the memory, a display device for displaying an image of the output image signal, a second circuit for compressing the digital image data from the memory into compressed image data, a telephone part having telephone functions, a line control circuit coupled to a public analog telephone line for selectively coupling the second circuit and the telephone part to the public analog telephone line, and a control device. The control device controls at least the memory and the second circuit so that the compressed image data related to the input image data is read out from the memory and supplied simultaneously to the first and second circuits in an image transmitting mode and the compressed image data related to a voice frequency signal received through the public analog telephone line is stored in the memory and read out therefrom to be supplied to the first circuit in an image receiving mode.
-
Citations
18 Claims
-
1. A video phone comprising:
-
input means for sequentially entering image data; digitizing means for digitizing said input image data into digital image data; memory means for sequentially storing said digital image data; image signal producing means for producing an output image signal based on said digital image data sequentially read out from said memory means; display means for sequentially displaying an image described by said output image signal; compression and expansion means for compressing said digital image data read out from said memory means into compressed image data in an image transmitting mode and for expanding compressed image data into digital image data in an image receiving mode; telephone means having telephone functions for transmitting and receiving a call; line control means coupled to a public analog telephone line for selectively coupling one of said compression and expansion means and said telephone means to said public analog telephone line, said line control means including modem means for modulating said compressed image data from said compression and expansion means into a voice frequency signal in the image transmitting mode and for demodulating a voice frequency signal received through said public analog telephone line into compressed image data in the image receiving mode; and control means for controlling at least said memory means and said compression and expansion means, said control means having means for freezing the image displayed on said display means at an arbitrary time by stopping the sequential storage of said digital image data into said memory means so that said compressed image data related to a frozen image is read out from said memory means and supplied simultaneously to said image signal producing means and said compression and expansion means in the image transmitting mode, said control means controlling said memory means and said compression and expansion means in the image receiving mode so that said compressed image data related to said voice frequency signal received through said public analog telephone line is first stored in said memory means and read out therefrom to be expanded in said compression and expansion means into digital image data which is then stored in said memory means, said digital image data being read out from said memory means to be supplied to said image signal producing means. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
2. A video phone comprising:
-
input means for sequentially entering image data; digitizing means for digitizing said input image data into digital image data, said digitizing means comprising means for producing three kinds of digital primary color signals as said digital image data; memory means for sequentially storing said digital image data; image signal producing means for producing an output image signal based on said digital image data sequentially read out from said memory means; display means for sequentially displaying an image described by said output image signal; compression and expansion means for compressing said digital image data read out from said memory means into compressed image data in an image transmitting mode and for expanding compressed image data into digital image data in an image receiving mode, said compression and expansion means comprising a compression part and an expansion part; telephone means having telephone functions for transmitting and receiving a call; line control means coupled to a public analog telephone line for selectively coupling one of said compression and expansion means and said telephone means to said public analog telephone line, said line control means including modem means for modulating said compressed image data from said compression and expansion means into a voice frequency signal in the image transmitting mode and for demodulating a voice frequency signal received through said public analog telephone line into compressed image data in the image receiving mode; and control means for controlling at least said memory means and said compression and expansion means, said control means having means for freezing the image displayed on said display means at an arbitrary time by stopping the sequential storage of said digital image data into said memory means so that said compressed image data related to a frozen image is read out from said memory means and supplied simultaneously to said image signal producing means and said compression and expansion means in the image transmitting mode, said control means controlling said compression and expansion means and said memory means in the image receiving mode so that said compressed image data related to said voice frequency signal received through said public analog telephone line is expanded into digital image data in said compression and expansion means and stored in said memory means and read out therefrom to be supplied to said image signal producing means, said compression part comprising first converting means for converting said digital primary color signals into a digital luminance signal and two kinds of digital color difference signals, a first modulator for modulating the digital luminance signal into a modulated digital luminance signal, and a second modulator for independently modulating the two kinds of digital color difference signals into two kinds of modulated digital color difference signals, said second modulator modulating at least one of the two kinds of digital color difference signals according to a second modulation system which is different from a first modulation system which is used by said first modulator, said expansion part comprising a first demodulator for demodulating said modulated digital luminance signal into said digital luminance signal, a second demodulator for demodulating said two kinds of modulated digital color difference signals into said two kinds of digital color difference signals, and second converting means for converting said digital luminance signal and said two kinds of digital color difference signals into three kinds of reproduced digital primary color signals.
-
-
13. A video phone comprising:
-
input means for sequentially entering image data; digitizing means for digitizing said input image data into digital image data; memory means for sequentially storing said digital image data; image signal producing means for producing an output image signal based on said digital image data sequentially read out from said memory means; display means for sequentially displaying an image described by said output image signal; compression and expansion means for compressing said digital image data read out from said memory means into compressed image data in an image transmitting mode and for expanding compressed image data into digital image data in an image receiving mode; telephone means having telephone functions for transmitting and receiving a call; line control means coupled to a public analog telephone line for selectively coupling one of said compression and expansion means and said telephone means to said public analog telephone line, said line control means including modem means for modulating said compressed image data from said compression and expansion means into a voice frequency signal in the image transmitting mode and for demodulating a voice frequency signal received through said public analog telephone line into compressed image data in the image receiving mode; control means for controlling at least said memory means and said compression and expansion means; and enabling and disabling means for enabling and disabling a monitoring of an image displayed on said display means, said control means having means for freezing the image displayed on said display means at an arbitrary time by stopping the sequential storage of said digital image data into said memory means so that said compressed image data related to a frozen image is read out from said memory means and supplied simultaneously to said image signal producing means and said compression and expansion means in the image transmitting mode, said control means controlling said compression and expansion means and said memory means in the image receiving mode so that said compressed image data related to said voice frequency signal received through said public analog telephone line is expanded into digital image data in said compression and expansion means and stored in said memory means and read out therefrom to be supplied to said image signal producing means, said enabling and disabling means comprising means for electrically enabling and disabling the display of the image on said display by controlling said line control means. - View Dependent Claims (14, 15, 16, 17, 18)
-
Specification