Display device also compatible with digital broadcasts

• US 20020030759A1
• Filed: 09/12/2001
• Published: 03/14/2002
• Est. Priority Date: 09/03/1997
• Status: Active Grant

• Current Assignee: Kazuhiko Yoshizawa, Masahisa Tsukahara, Toshimitsu Watanabe, Yukimi Saiki
• Original Assignee: Kazuhiko Yoshizawa, Masahisa Tsukahara, Toshimitsu Watanabe, Yukimi Saiki
• Inventors: Tsukahara, Masahisa, Yoshizawa, Kazuhiko, Watanabe, Toshimitsu, Saiki, Yukimi
• Granted Patent: US 6,529,245 B2
• Time in Patent Office: Days
• US Class Current: 348/511
• CPC Class Codes: H04N 3/227 Centering
• CPC Class Codes: H04N 5/46 for receiving on more than one standard at will deflecting circuits of multi-standard receivers H04N3/27
• CPC Class Codes: H04N 5/68 Circuit details for cathode-ray display tubes deviation circuits H04N3/16
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229

Abstract

A digital television signal receiver includes a decoder, capable of decoding digital television signals having a plurality of different formats, which outputs video information in which image fields having mutually different numbers of scanning lines appear aperiodically when the decoder decodes a digital television signal having a specific one of the different formats; a display device which displays an image based on the video information output from the decoder; and an image controller which sets respective display start positions for the image fields having mutually different numbers of scanning lines to a same display start position in a vertical direction when the display device displays an image based on the video information output from the decoder when the decoder decodes the digital television signal having the specific format.

Claims

1. A digital television signal receiver comprising:

a decoder, capable of decoding digital television signals having a plurality of different formats, which outputs video information in which image fields having mutually different numbers of scanning lines appear aperiodically when the decoder decodes a digital television signal having a specific one of the different formats;

a display device which displays an image based on the video information output from the decoder; and

an image controller which sets respective display start positions for the image fields having mutually different numbers of scanning lines to a same display start position in a vertical direction when the display device displays an image based on the video information output from the decoder when the decoder decodes the digital television signal having the specific format.

2. A digital television signal receiver according to claim 1, wherein the display device scans the image in the vertical direction based on a vertical ramp waveform;

and

wherein the image controller includes a controlling circuit which controls one of a DC level and an amplitude of the vertical ramp waveform.

3. A digital television signal receiver according to claim 2, wherein the vertical ramp waveform includes a vertical retrace period;

and

wherein the controlling circuit includes a clamp circuit which maintains a DC level of the vertical ramp waveform during the vertical retrace period constant for each of the image fields having mutually different numbers of scanning lines.

4. A digital television signal receiver according to claim 1, wherein the display device scans the image in the vertical direction based on a vertical ramp waveform including a vertical retrace period;

and

wherein the image controller includes a voltage controlling circuit which controls a voltage of the vertical ramp waveform during the vertical retrace period.

5. A digital television signal receiver according to claim 1, further comprising a clock generating circuit which generates clocks for use in decoding the digital television signals;

and

wherein the decoder decodes the digital television signals using the clocks generated by the clock generating circuit.