Patent US3798357A successfully refreshed from Google Patents.
US3798357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording and reproducing system
Assignee: Sony Corp
•
Filing: 1972-11-30
•
Granted: 1974-03-19
•
Expires: 1992-11-30
Abstract
Abstract In a system in which at least the chrominance components of composite color television signals are recorded during alternate line intervals and omitted during the remaining line intervals to form a checkerboard array on the recording medium and are recreated by combining reproduced chrominance components with delayed replicas, additional phase inversion circuits are provided to recreate PAL signals. The red color difference components of PAL composite signals are modulated on the color subcarrier in one phase on alternate lines and the opposite phase during the remaining lines. The inversion circuits include circuits for generating two conversion frequencies of such values that one of them reconverts alternate line intervals to have one phase condition and the other reconverts the remaining line intervals to have the opposite phase condition, thus recreating a PAL signal.
Inventors
- 👤 H Narahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:36
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/80; H04N9/86
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
246 words
A system for reproducing PAL composite color television signals from a magnetic recording in which alternate line intervals of at least frequency converted chrominance signals are recorded, said system comprising: A. means to generate a first signal having a frequency equal to the sum of the PAL television color subcarrier frequency and the subcarrier frequency of the frequency-converted signal; B. means to generate a second signal having a frequency equal to the difference between the PAL television color subcarrier frequency and the subcarrier frequency of the frequency converted signal; C. a first chrominance channel comprising: 1. a first frequency reconverter, 2. means to apply said frequency converted signal and said first signal to said first frequency reconverter, and 3. means to select from the output of said fIrst reconverter a first reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency: D. a second chrominance channel comprising: 1. a second frequency reconverter, 2. means to apply said frequency converted signal and said second signal to said second frequency reconverter, and 3. means to select from the output of said second reconverter a second reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency; E. means connected to one of said channels to delay one of said chrominance signals one line interval; and F. means to combine, alternately, one line interval of said first reconverted chrominance signal and one line interval of said second reconverted chrominance signal.
Claim 2
Independent Claim
246 words
A system for reproducing PAL composite color television signals from a magnetic recording in which alternate line intervals of at least frequency converted chrominance signals are recorded, said system comprising: A. means to generate a first signal having a frequency equal to the sum of the PAL television color subcarrier frequency and the subcarrier frequency of the frequency-converted signal; B. means to generate a second signal having a frequency equal to the difference between the PAL television color subcarrier frequency and the subcarrier frequency of the frequency converted signal; C. a first chrominance channel comprising: 1. a first frequency reconverter, 2. means to apply said frequency converted signal and said first signal to said first frequency reconverter, and 3. means to select from the output of said fIrst reconverter a first reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency: D. a second chrominance channel comprising: 1. a second frequency reconverter, 2. means to apply said frequency converted signal and said second signal to said second frequency reconverter, and 3. means to select from the output of said second reconverter a second reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency; E. means connected to one of said channels to delay one of said chrominance signals one line interval; and F. means to combine, alternately, one line interval of said first reconverted chrominance signal and one line interval of said second reconverted chrominance signal.
Claim 3
Dependent Claim
17 words
means to apply said frequency converted signal and said first signal to said first frequency reconverter, and
Claim 4
Dependent Claim
17 words
means to apply said frequency converted signal and said first signal to said first frequency reconverter, and
Claim 5
Dependent Claim
17 words
means to apply said frequency converted signal and said second signal to said second frequency reconverter, and
Claim 6
Dependent Claim
17 words
means to apply said frequency converted signal and said second signal to said second frequency reconverter, and
Claim 7
Dependent Claim
29 words
The system of claim 1 in which said delay means is connected between said means to select the reconverted chrominance signal in that channel and said means to combine.
Claim 8
Dependent Claim
70 words
means to select from the output of said second reconverter a second reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency; E. means connected to one of said channels to delay one of said chrominance signals one line interval; and F. means to combine, alternately, one line interval of said first reconverted chrominance signal and one line interval of said second reconverted chrominance signal.
Claim 9
Dependent Claim
70 words
means to select from the output of said second reconverter a second reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency; E. means connected to one of said channels to delay one of said chrominance signals one line interval; and F. means to combine, alternately, one line interval of said first reconverted chrominance signal and one line interval of said second reconverted chrominance signal.
Claim 10
Dependent Claim
45 words
The system of claim 1 comprising, in addition: A. means to reproduce, from said magnetic recording, the luminance portion of said color television signals; and B. means to combine said luminance portion with said alternate line intervals of said first and second reconverted chrominance signals.
Claim 11
Dependent Claim
33 words
means to select from the output of said fIrst reconverter a first reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency: D. a second chrominance channel comprising:
Claim 12
Dependent Claim
33 words
means to select from the output of said fIrst reconverter a first reconverted chrominance signal having a subcarrier frequency equal to the PAL television color subcarrier frequency: D. a second chrominance channel comprising:
Claim 13
Dependent Claim
65 words
The system of claim 1 in which said means to combine comprises: A. a first input terminal connected to said first channel; B. a second input terminal connected to said first channel; C. an output terminal; and D. means to connect said first and second input terminals to receive, alternately, said first and second reconverted chrominance signals applied to said first and second input terminals.
Claim 14
Dependent Claim
26 words
The system of claim 4 in which said means to combine comprises single-pole-double-throw switching means, and said means to connect said first and second input terminals.
Claim 15
Dependent Claim
60 words
The system of claim 5 comprising, in addition: A. detecting means to detect the presence of chrominance channel; and B. means controlled by said detecting means to control said switching means to connect said output terminal to said first and second input terminals during alternate line intervals corresponding to the intervals during which frequency reconverted chrominance signals are applied thereto.
Claim 16
Dependent Claim
52 words
The system of claim 6 in which said detecting means comprises: A. a burst gate connected to one of said channels; and B. gate pulse generating means synchronized by horizontal synchronizing signals of said composite signal to allow said burst gate to pass only burst signals from said one of said channels.
Claim 17
Dependent Claim
20 words
The system of claim 7 in which said burst gate is connected to the other channel from said delay means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |