Abstract An apparatus for transmitting and receiving an image signal in use of a telephone line, comprising an image signal processing section including a central processing unit (6) for controlling the whole operation of the apparatus, an A/D converter (2) for converting an image signal outputted from a camera (1) into a digital signal and a memory (3) for storing the digital signal from the A/D convertor and reading out the stored digital data under a control of the central processing unit, an image signal transmitting section for converting the digital data outputted from the image signal processing unit into a sinusoidal wave signal of a predetermined frequency corresponding to the digital data and transmitting the sinusoidal wave signal of the predeteimined frequency to a telephone line interface circuit (12), and an image signal receiving section for counting a frequency of a sinusoidal wave signal received through the telephone line interface circuit, converting the counted. value into an origianl image signal and displaying the image signal on a monitor (19). The present apparatus is capable of transmitting and receiving much information of image data at high speed.
An apparatus for transmitting and receiving an image signal in use of a telephone line, comprising : image signal processing means including a central processing unit (6) for controlling the whole operation of the apparatus, an A/D converter (2) for converting an image signal outputted from a camera (1) into a digital signal, and a memory (3) for storing the digital signal from said A/D converter (2) and reading out the stored digital data under control of said central processing unit (6) ; image signal transmitting means for converting the digital data outputted from said image signal processing means into a sinusoidal wave signal of a predetermined frequency corresponding to the digital data and transmitting the sinusoidal wave signal of the predetermined frequency to a telephone line interface circuit (20) ; and image signal receiving means for counting a frequency of a sinusoidal wave signal received through said telephone line interface circuit, converting the counted value into an original image signal and displaying the image signal on a monitor (19).
Claim 2
Dependent Claim
116 words
An apparatus for transmitting and receiving an image signal in use of a telephone line, as set forth in Claim 1, wherein said image signal transmitting means includes ; first oscillating means (9) for generating a predetermined frequency of oscillation signal ; first frequency-dividing means (8) for frequency-dividing said oscillation signal from said first oscillating means ; data/frequency converting means (7) for converting the digital data from said memory into the predetermined frequency of sinusoidal wave signal in response to the frequency-divided signal from said first frequency-dividing means ; and amplifying means (10) for amplifying an output signal from said data/frequency converting means (7) and sending the amplified signal to said telephone line interface circuit (20).
Claim 3
Dependent Claim
86 words
An apparatus for transmitting and receiving an image signal in use of a telephone line, as set forth in Claim 2, wherein said data/frequency converting means (7) includes : second programmable frequency-dividing means (50) for converting the digital data from said memory (3) into a predetermined frequency of square wave signal in response to the frequency-divided signal from said first frequency-dividing means ; and square wave/sinusoidal wave converting means (51) for converting an output signal from said second programmable frequency-dividing means into the sinusoidal wave signal.
Claim 4
Dependent Claim
163 words
An apparatus for transmitting and receiving an image signal in use of a telephone line, as set forth in Claim 1, 2 or 3, wherein said image signal receiving means includes : receiving amplifying means (13) for amplifying the sinusoidal wave signal received through said telephone line interface circuit (12) ; zero-point detecting means (14) for detecting a zero-point of an output signal from said receiving amplifying means to output a square wave signal ; second oscillating means (16) for generating a predetermined frequency of oscillation signal ; frequency counting means for counting a frequency of an output signal from said zero-point detecting means in response to said oscillation signal from said second oscillating means ; frequency/data converting means (17) for converting an output signal from said frequency counting means into original digital data ; and D/A converting means (18) for converting an output signal from said frequency/data converting means into an analog signal and displaying the analog signal on said monitor (19).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.