Digital color television system

• US 4,015,286 A
• Filed: 01/23/1975
• Issued: 03/29/1977
• Est. Priority Date: 01/23/1975
• Status: Expired due to Term

• Current Assignee: Optical Recording Corp.
• Original Assignee: Eli S. Jacobs
• Inventors: Russell, James T.
• Primary Examiner(s): Martin, John C.
• Application Number:
  US05/543,361
• Time in Patent Office: 796 Days
• Field of Search: 358/4, 358/12, 358/13
• US Class Current: 386/216
• CPC Class Codes: H04N 9/804 involving pulse code modulation of the colour picture signal components

Abstract

A digital color television system is described in which only one chrominance component of the video color television signal is transmitted for each television line, and digital delay means is employed for delaying at least one of the two chrominance components I and Q of the color television signal so that the delayed chrominance component can be added to the transmitted television signal to produce output signals having both chrominance components. The system includes a recording apparatus for recording the digital color television signal on a record which may be an optical or magnetic record, and a playback apparatus for playing back the recorded signal to a television receiver or other utilization device. A gate means is provided in the recording apparatus for selectively transmitting a conventional digital color television signal having two chrominance components as an altered digital television signal having only one chrominance component per line which is different on alternate lines. As a result, the amount of information stored on the record is greatly reduced. In one embodiment of the system, the two chrominance components I and Q are recorded between luminance words Y with different chrominance components recorded in alternate television lines. A single digital storage means such as a shift register is used in the playback apparatus. In the other embodiment, the chrominance components are recorded at the end of each television line in the horizontal blanking region, with different chrominance components being recorded in alternate lines. This necessitates two digital storage means of the recirculating type in the playback unit, one storage means for each of the two chrominance components because both are recorded out of their proper sequence with the luminance words.

Claims

1. A digital color television system comprising:

input means for supplying a digital video color television line signal including a luminance signal component and two different chrominance signal components, said input means including a plurality of digital storage means for storing said digital line signal components so that said two chrominance components are each stored in different storage means;

gate means connected to the outputs of said plurality of storage means, and including control logic means for selectively transmitting said television line signal components through said gate means so that altered digital television line signals are produced at the output of the gate means which each include a luminance component and only one of said two chrominance components with said two chrominance components alternating in successive television line signals;

said gate means causing chrominance component words and corresponding luminance component words to be provided in the altered digital line signal at positions adjacent each other, each of said words being shorter than one television line, so that successive luminance words in the same television line are separated by the chrominance words in an alternating manner;

digital delay means for delaying the chrominance components of the altered digital television line signals to produce delayed digital chrominance components at the output of said delay means; and

output means for combining the delayed chrominance components with components of said altered line signals to produce a television line signal output including a luminance component and two different chrominance components at least one of which was obtained from an altered line signal other than that from which its luminance component was obtained.

2. A television system in accordance with claim 1 which also includes recorder means for recording the altered digital television line signals on a record, and playback means for playing back said record to transmit the recorded altered line signals through said digital delay means.

3. A television system in accordance with claim 2 in which the record is an optical digital record.

4. A television system in accordance with claim 1 in which the digital delay means delays the chrominance component a time delay greater than the duration of one luminance word.

5. A television system in accordance with claim 4 in which the time delay is at least as long as one television line.

6. A television system in accordance with claim 1 which also includes coupling means for transmitting a portion of the chrominance components of the altered line signals to the output means without passing through said delay means to provide an undelayed chrominance component which is combined with the luminance component and with a delayed chrominance component of different type than said undelayed chrominance component to form the line signal output.

7. A digital color television signal playback apparatus comprising:

an optical record having altered digital color television line signals recorded thereon each including a luminance signal component and only one chrominance signal component, with two different chrominance signal components being provided in an alternating manner in successive television line signals, said chrominance components being formed by the actual color values present in the television line signal;

said record having chrominance component words and luminance component words forming the altered line signals, recorded thereon at positions adjacent each other, each of said words being shorter than one television line, so that the successive luminance words in the same television line signal are separated by the chrominance words in an alternating manner;

playback means for playing back said record to reproduce said altered line signals;

digital delay means for delaying the chrominance components of the altered digital television line signals to produce delayed chrominance components; and

output means for combining the delayed chrominance components with components of said altered line signals to produce a television line signal output including a luminance component and two different chrominance components at least one of which was obtained from an altered line signal other than that from which its luminance component was obtained.

8. A television playback apparatus in accordance with claim 7 which also includes means for transmitting a portion of the chrominance components of the altered line signals to the output means without pasing through said delay means to provide an undelayed chrominance component which is combined with the luminance component and with a delayed chrominance component of different type, the said undelayed chrominance component to form the line signal output.

9. A digital color television system, comprising:

input means for supplying a digital video color television signal including a luminance signal component and two different chrominance signal components;

gate means for selectively transmitting said television signal so that altered digital television line signals are produced at the output of the gate means which each include a luminance component and only one of said two chrominance components with said two chrominance components alternating in successive television line signals;

digital delay means for delaying the chrominance components of the altered digital television line signals to produce delayed chrominance components, said digital delay means including first and second delay means for delaying the two different chrominance components of successive altered line signals and for transmitting the two delayed chrominance components to the output means which combines them with the luminance component to form the line signal output, each of said first and second delay means delaying only one of said two different chrominance components; and

output means for combining the delayed chrominance components with components of said altered line signals to produce a television line signal output including a luminance component and two different chrominance components at least one of which was obtained from an altered line signal other than that from which its luminance component was obtained.

10. A television system in accordance with claim 9 in which the gate means is operated to cause successive luminance words to be provided in the altered digital line signal without intervening chrominance words and successive chrominance words to be provided without intervening luminance words in said altered line signal.

11. A television system in accordance with claim 10 in which the chrominance words are provided at the end of the line signal at a time corresponding to the horizontal blanking time of the television signal.

12. A digital color television signal playback apparatus comprising:

a record having altered digital color television line signals recorded thereon each including a luminance signal component and only one chrominance signal component, with two different chrominance signal components being provided in an alternating manner in successive television line signals;

playback means for playing back said record to reproduce said altered line signals;

digital delay means for delaying the chrominance components of the altered digital television line signals to produce delayed chrominance components, said digital delay means including first and second delay means for delaying the two different chrominance components of successive altered line signals and for transmitting the two delayed chrominance components to the output means which combines them with the luminance component to formthe line signal output, each of said first and second delay means delaying only one of said two different chrominance components; and

output means for combining the delayed chrominance components with components of said altered line signals to produce a television line signal output including a luminance component and two different chrominance components at least one of which was obtained from an altered line signal other than that from which its luminance component was obtained.

13. A television playback apparatus in accordance with claim 12 in which successive luminance words of the altered digital line signal are recorded on the record without intervening chrominance words and successive chrominance words are recorded without intervening luminance words in said altered line signal.

14. A television playback apparatus in accordance with claim 13 in which the chrominance words are recorded at the end of the line signal at a time corresponding to the horizontal blanking time of the television signal.