Sony Corporation

Nippon Telegraph and Telephone Corporation

Yoshihiro Hanamoto

Satoru Maeda

Yoshio Ishigaki

Hiroshi Sahara

Ikuo Taniguchi

Yasushi Noguchi

Koichi Katagiri

Michiro Shibui

An apparatus for scrolling the display of images obtained from a plurality of data units, each having pattern signals representing a plurality of horizontal lines and a corresponding color signal includes a video display having a plurality of horizontal display lines, a first memory for storing the pattern signals formed with first addresses corresponding to the plurality of horizontal display lines and a first buffer area for temporarily storing received pattern signals, a second memory for storing the color signal formed with second addresses corresponding to the numbers of the data units and a second buffer area for temporarily storing a received color signal, the pattern signals and a corresponding color signal being stored in the first and second buffer areas, respectively. A read out system operates so that the first memory, including the first buffer area, is read out by accessing the first addresses in a pre-determined order and so that the second memory, including the second buffer area, is read out by accessing the second addresses in a pre-determined order. Also provided is a circuit for transferring the pattern signal of a horizontal line stored in the first buffer area to a corresponding address of the first memory and for transferring a corresponding color signal stored in the second buffer area to a corresponding address of the second memory, and a circuit for supplying the pattern signals and the corresponding color signal to the display tube.

Apparatus for displaying scrolling images

A signal generator circuit for a television receiver employed in a videotex or CAPTAIN system comprises a reference signal oscillator for producing a reference signal and a synchronizing signal generator for generating a horizontal synchronization signal synchronized with the reference signal. A frequency divider is responsive to the reference signal for producing a color sub-carrier signal. A phase-locked loop is responsive to the sub-carrier signal and includes a voltage-controlled oscillator. The voltage-controlled oscillator produces an output signal synchronized with the sub-carrier signal and having a series of rising edges. A rising edge of the sub-carrier signal periodically coincides with a rising edge of the signal from the voltage-controlled oscillator. A detector detects a time when a rising edge of the sub-carrier signal coincides with a rising edge of the output signal of the voltage-controlled oscillator, and a clock signal is then generated synchronized with the output signal of the voltage-controlled oscillator and having a series of falling edges. The horizontal synchronization signal generator and the clock signal generator are controlled so as to ensure that the rising edge of the horizontal synchronization signal coincides with a falling edge of the clock signal. This ensures an accurate count of the pulses for determining the horizontal position of a display by the receiver and prevents horizontal jitter in the display.

Signal generator circuit

Growing community of inventors

Hyogo, Japan

Yoshihiro Hanamoto