Video display apparatus with scan conversion and reversion and a video display method using scan conversion and reversion

• US 6,429,899 B1
• Filed: 07/13/1999
• Issued: 08/06/2002
• Est. Priority Date: 07/16/1998
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fujita, Masaaki, Okumura, Naoji, Miyata, Minoru, Tanaka, Kazuto, Okamoto, Satoshi, Terai, Katsumi, Nio, Yutaka
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US09/351,847
• Time in Patent Office: 1,120 Days
• Field of Search: 348/448, 348/458, 348/441, 348/553, 348/578, 348/206, 348/459, 348/806
• US Class Current: 348/443
• CPC Class Codes: G09G 1/165 Details of a display terminal using a CRT, the details relating to the control arrangement of the display terminal and to the interfaces thereto details suitable for both CRT and flat panel G09G5/003; specific for a flat panel G09G3/2092
• CPC Class Codes: G09G 1/167 Details of the interface to the display terminal specific for a CRT details suitable for both CRT and flat panel G09G5/006, specific for a flat panel G09G3/2096
• CPC Class Codes: G09G 2310/0229 De-interlacing
• CPC Class Codes: H04N 3/30 otherwise than with constant velocity or otherwise than in pattern formed by unidirectional, straight, substantially horizontal or vertical lines
• CPC Class Codes: H04N 7/01 Conversion of standards , e.g. involving analogue television standards or digital television standards processed at pixel level
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229
• CPC Class Codes: H04N 7/0125 one of the standards being a high definition standard

Abstract

A video signal of an interlaced scanning system having 525 scanning lines and a vertical scanning frequency of 60 Hz is converted to a video signal having 1050 scanning lines and a vertical scanning frequency of 120 Hz, for displaying an image by bidirectional scanning. A vertical synchronizing signal is subjected to offset processing by a ¼ horizontal scanning period when an odd field is started, thereby keeping interlaced relation between odd and even fields. The vertical synchronizing signal is subjected to offset processing by a ½ horizontal scanning period every frame, so that the scanning direction for each scanning line is reversed every frame.

Claims

1. A video display apparatus comprising:

a conversion circuit receiving a first video signal of an interlaced scanning system or a progressive scanning system including a first number of scanning lines in each frame and having a first vertical scanning frequency and converting said first video signal to a second video signal of a progressive scanning system including a second number of scanning lines in each frame and having a second vertical scanning frequency, wherein said second vertical scanning frequency is equal to said first vertical scanning frequency;

a scanning line reversion circuit alternately reversing the time base of said second video signal output from said conversion circuit every scanning line and outputting processed said second video signal as a third video signal; and

a display part displaying said third video signal output from said scanning line reversion circuit by bidirectional scanning in synchronization with a vertical synchronizing signal and a horizontal synchronizing signal after conversion by said conversion circuit.

2. A video display apparatus comprising:

a conversion circuit receiving a first video signal of an interlaced scanning system or a progressive scanning system including a first number of scanning lines in each frame and having a first vertical scanning frequency and converting said first video signal to a second video signal of a progressive scanning system including a second number of scanning lines in each frame and having a second vertical scanning frequency, wherein said second vertical scanning frequency is even times said first vertical scanning frequency;

a scanning line reversion circuit alternately reversing the time base of said second video signal output from said conversion circuit every scanning line and outputting processed said second video signal as a third video signal;

a display part displaying said third video signal output from said scanning line reversion circuit by bidirectional scanning in synchronization with a vertical synchronizing signal and a horizontal synchronizing signal after conversion by said conversion circuit; and

a second offset circuit displacing said vertical synchronizing signal so that a plurality of fields included in each frame keep interlaced relation.

3. The video display apparatus in accordance with claim 2, wherein

said second vertical scanning frequency is twice said first vertical scanning frequency, and

said second offset circuit displaces said vertical synchronizing signal by a second offset time every other field of each frame.

4. The video display apparatus in accordance with claim 3, wherein

said second offset time is {fraction (1/4+L )} a horizontal scanning period.

5. A video display apparatus comprising:

a conversion circuit receiving a first video signal of an interlaced scanning system or a progressive scanning system including a first number of scanning lines in each frame and having a first vertical scanning frequency and converting said first video signal to a second video signal of a progressive scanning system including a second number of scanning lines in each frame and having a second vertical scanning frequency, wherein said first video signal is of an interlaced scanning system, said first number is an odd number, said first vertical scanning frequency is even times said second vertical scanning frequency, and each frame includes a plurality of fields;

a scanning line reversion circuit alternately reversing the time base of said second video signal output from said conversion circuit every scanning line and outputting processed said second video signal as a third video signal;

a display part displaying said third video signal output from said scanning line reversion circuit by bidirectional scanning in synchronization with a vertical synchronizing signal and a horizontal synchronizing signal after conversion by said conversion circuit; and

a third offset circuit displacing said vertical synchronizing signal so that said plurality of fields of each frame keep interlaced relation.

6. A video display method comprising steps of:

receiving a first video signal of an interlaced scanning system or a progressive scanning system including a first number of scanning lines in each frame and having a first vertical scanning frequency and converting said first video signal to a second video signal of a progressive scanning system including a second number of scanning lines in each frame and having a second vertical scanning frequency, wherein said second vertical scanning frequency is equal to said first vertical scanning frequency;

alternately reversing the time base of said second video signal every scanning line and outputting processed said second video signal as a third video signal; and

displaying said third video signal by bidirectional scanning in synchronization with a vertical synchronizing signal and a horizontal synchronizing signal after conversion.

7. A video display method comprising steps of:

receiving a first video signal of an interlaced scanning system or a progressive scanning system including a first number of scanning lines in each frame and having a first vertical scanning frequency and converting said first video signal to a second video signal of a progressive scanning system including a second number of scanning lines in each frame and having a second vertical scanning frequency, wherein said second vertical scanning frequency is even times said first vertical scanning frequency;

alternately reversing the time base of said second video signal every scanning line and outputting processed said second video signal as a third video signal;

displaying said third video signal by bidirectional scanning in synchronization with a vertical synchronizing signal and a horizontal synchronizing signal after conversion; and

displacing said vertical synchronizing signal so that a plurality of fields included in each frame keep interlaced relation.

8. The video display method in accordance with claim 7, wherein

said second vertical scanning frequency is twice said first vertical scanning frequency, and

said step of displacing said vertical synchronizing signal includes a step of displacing said vertical synchronizing signal by a second offset time every other field of each frame.

9. The video display method in accordance with claim 8, wherein

said second offset time is {fraction (1/4+L )} a horizontal scanning period.

10. A video display method comprising steps of:

receiving a first video signal of an interlaced scanning system or a progressive scanning system including a first number of scanning lines in each frame and having a first vertical scanning frequency and converting said first video signal to a second video signal of a progressive scanning system including a second number of scanning lines in each frame and having a second vertical scanning frequency, wherein said first video signal is of an interlaced scanning system, said first number is an odd number, said first vertical scanning frequency is even times said second vertical scanning frequency, and each frame includes a plurality of fields;

alternately reversing the time base of said second video signal every scanning line and outputting processed said second video signal as a third video signal;

displaying said third video signal by bidirectional scanning in synchronization with a vertical synchronizing signal and a horizontal synchronizing signal after conversion; and

displacing said vertical synchronizing signal so that said plurality of fields of