EP0501718A1
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EP
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Colour television camera apparatus and colour television signal generating methods
Assignee: Sony Corp
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Filing: 1992-02-24
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Granted: —
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Expires: 2012-02-24
Abstract
Abstract In a colour television camera apparatus, a 2fs-rate luminance signal and fs-rate chrominance signals are selectively generated by a matrix circuit (8), in conformity with a plurality of standard systems, from 2fs-rate three-colour image pick-up signals generated by an image signal pick-up unit (3, 4). The fs-rate chrominance signals are modulated by a modulating circuit (12) into fs-rate modulated chrominance signals which are converted by a rate converter (13) into 2fs-rate modulated chrominance signals. The 2fs-rate luminance signals and the 2fs-rate modulated chrominance signals are combined by an adder (14) into 2fs-rate digital composite video signals which are converted by a D/A converter (15) into analogue composite video signals. In this manner, analogue composite video signals, in which the bandwidth of the luminance signals has been enhanced up to the sampling frequency fs, may be selectively output in conformity with a plurality of standard systems.
Inventors
- 👤 Kazuyoshi c/o Patents Division Miyamoto
- 👤 Takashi C/O Patents Division Asaida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:18
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/77; H04N25/00; H04N25/40; H04N25/44; H04N25/447; H03; H03M; H03M1/00; H03M1/12; H03M1/66; H04N11/00; H04N11/06; H04N11/12; H04N11/14; H04N11/16; H04N23/00; H04N23/10; H04N9/64; H04N9/67; H10; H10F; H10F39/00; H10F39/10; H10F39/12; H04N2209/00; H04N2209/04; H04N2209/041; H04N2209/042; H04N2209/045; H04N2209/046; H04N2209/048; H04N2209/049
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
189 words
A colour television camera apparatus comprising: image signal generating means (6, 7) for generating digital three-colour image signals at 2fs-rate (where fs≃4f sc , and f sc is the sampling clock rate); luminance signal generating means (8) for selectively generating a digital luminance signal at 2fs-rate for a plurality of video standard systems from the digital three-colour image signals; chrominance signal generating means (8) for selectively generating a digital chrominance signal at fs-rate for the plurality of video standard systems from the digital three-colour image signals; modulating means (12) for modulating said fs-rate digital chrominance signals; rate converting means (13) for converting modulated chrominance signals from said modulating means (12) into 2fs-rate signals, said rate converting means (13) including filter means having a plurality of transfer functions, said transfer function being selected according to the selected video standard system; composite video signal generating means (14) for generating a digital composite video signal at 2fs-rate according to the 2fs-rate digital luminance signal and the 2fs-rate modulated chrominance signal from the rate converting means; and digital-to-analogue converting means (15) for converting said 2fs-rate digital composite video signal into an analogue signal.
Claim 2
Dependent Claim
66 words
A colour television camera apparatus according to claim 1 wherein said image signal generating means (6, 7) comprises three CCD image sensors (4), analogue-to-digital converting means (6) for converting output signals from said three CCD image sensors (4) into digital image signals, and interpolating means (7) for generating the digital three-colour image signal at 2fs-rate by interpolating the digital image signals from said analogue-to-digital converting means.
Claim 3
Dependent Claim
24 words
A colour television camera apparatus according to claim 1 wherein said plurality of video standard systems are the NTSC system and the PAL system.
Claim 4
Dependent Claim
21 words
A colour television camera apparatus according to claim 1 further comprising an output terminal (21) for outputting the 2fs-rate luminance signal.
Claim 5
Dependent Claim
43 words
A colour television camera apparatus according to claim 3 wherein said PAL system comprises a first PAL system having a 908f H (where f H is the horizontal scanning frequency) clock rate, and a second PAL system having a 944f H clock rate.
Claim 6
Dependent Claim
40 words
A colour television camera apparatus according to claim 1 wherein said chrominance signal generating means (8) has down-sampling means having a filter having a zero point at least at the frequency fs, for generating the fs rate digital chrominance signals.
Claim 7
Dependent Claim
170 words
A colour television camera apparatus according to claim 3 further comprising first low-pass filter means (10) connected to a first chrominance output terminal of the chrominance signal generating means (8) for filtering an output signal from the first chrominance output terminal, said first low-pass filter means (10) having a transfer function given by: H₁₀(z) = 1 2⁸ (z⁻²+2z⁻¹+1)²(z⁻⁴+2z⁻²+1) (-z⁻⁶+2z⁻⁴+2z⁻³+z⁻²-1) second low-pass filter means (11) connected to a second chrominance output terminal of the chrominance signal generating means (8) for filtering an output signal from the second chrominance output terminal, said second low-pass filter means (11) having a transfer given by: H 11Q (z) = 1 2¹¹ (z⁻³+1) (z⁻¹+1) (3z⁻⁴+2z⁻²+3) (z⁻²+2z⁻¹+1) (z⁻⁴+2z⁻²+1) (-z⁻⁸+2z⁻⁵+2z⁻⁴+z⁻³-1) and H 11U (z) = 1 2⁸ (z⁻²+2z⁻¹+1)²(z⁻⁴+2z⁻²+1) (-z⁻⁶+2z⁻⁴+2z⁻³+z⁻²-1) said transfer function H 11Q (z) is selected when the NTSC mode is selected, said transfer function H 11U (z) is selected when the PAL mode is selected, and the output signal of the first and second low-pass filter means (10, 11) is supplied to the modulating means (12).
Claim 8
Dependent Claim
82 words
A colour television camera apparatus according to claim 5 wherein said plurality of transfer functions are: H 13A (z) = 1 2⁶ (-11z⁻⁶+33z⁻⁴+64z⁻³+33z⁻²-11) H 13B (z) = 1 2³ (-3z⁻⁶+2z⁻⁴+8z⁻³+2z⁻²-3) and H 13C (z) = 1 2⁵ (-9z⁻⁶+12z⁻⁴+32z⁻³+12z⁻²-9), said transfer function H 13A (z) is selected when the NTSC mode is selected, said transfer function H 13B (z) is selected when the first PAL mode is selected, said transfer function H 13C (z) is selected when the second PAL mode is selected.
Claim 9
Dependent Claim
132 words
A colour television signal generating method, said method comprising: generating digital three-colour image signals at 2fs-rate (where fs≃4f sc , and f sc is the sampling clock rate); selectively generating a digital luminance signal at 2fs-rate for a plurality of video standard systems from the digital three-colour image signals; selectively generating a digital chrominance signal at fs-rate for the plurality of video standard systems from the digital three-colour image signals; modulating said fs-rate digital chrominance signals; converting the modulated chrominance signals into 2fs-rate signals by filtering the demodulated chrominance signal using selected transfer functions according to the selected video standard system; generating digital composite video signal at 2fs-rate from the 2fs-rate digital luminance signal and the 2fs-rate modulated chrominance signal; and converting said 2fs-rate digital composite video signal into an analogue signal.
Claim 10
Dependent Claim
25 words
A colour television signal generating method according to claim 9 wherein said plurality of video standard systems are the NTSC system and the PAL system.
References Cited (Backward Citations)
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