US5311297A
Expired / Lapsed
US
⏱️ 0.0 years remaining
HDTV to conventional TV signal converting apparatus with non-linear level correction
Assignee: Panasonic Holdings Corp
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Filing: 1991-06-03
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Granted: 1994-05-10
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Expires: 2011-06-03
Abstract
Abstract A television signal converting apparatus receives a high definition television signal which is processed approximately linearly on the transmission and receiving sides and whose transmission only is processed non-linearly. A non-linear level correction circuit is provided, which collectively simultaneously carries out two kinds of non-linear processes, namely, a transmission inverse gamma correction and a CRT gamma correction, which are executed on the transmission side, thus precisely reproducing the signal level of a luminance signal by using a small-scale circuit.
Inventors
- 👤 Yoshio Seki
- 👤 Atsushi Ishizu
- 👤 Masaki Tokoi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:51
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/015; H04N7/0152; H04N7/01; H04N7/0125; H04N7/0135; H04N9/00; H04N9/64; H04N9/642; H04N9/67; H04N9/68; H04N9/69
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
243 words
A television signal converting apparatus for converting a high-definition television signal having a larger number of scanning lines than that of a conventional television signal into the conventional television signal, said high definition television signal having been bandwidth compressed and processed so as to have a non-linear level expansion characteristic at a transmission side and transmitted from the transmission side in the form of a band-compressed television signal, said apparatus comprising: a non-linear correction means for correcting a signal level of the transmitted band-compressed television signal based on a predetermined non-linear characteristic; a signal converting means for converting an output signal of said non-linear correction means to the conventional television signal, said signal converting means comprising an interpolation means coupled to said non-linear correction means for interpolating the band-compressed television signal to restore the high-definition television signal, and a scanning line density converting means for changing the number of scanning lines of the high-definition television signal restored by said interpolation means to the number of scanning lines of the conventional television signal; an inverse matrix means coupled to said signal converting means for producing three primary color signals from an output signal of said scanning line density converting means; and a picture display means coupled to said inverse matrix means for displaying the three primary signals; wherein said non-linear level correction means corrects for a difference between said non-linear level expansion characteristic and a non-linear electro-optic conversion characteristic of said picture display means.
Claim 2
Dependent Claim
243 words
A television signal converting apparatus for converting a high-definition television signal having a larger number of scanning lines than that of a conventional television signal into the conventional television signal, said high definition television signal having been bandwidth compressed and processed so as to have a non-linear level expansion characteristic at a transmission side and transmitted from the transmission side in the form of a band-compressed television signal, said apparatus comprising: a non-linear correction means for correcting a signal level of the transmitted band-compressed television signal based on a predetermined non-linear characteristic; a signal converting means for converting an output signal of said non-linear correction means to the conventional television signal, said signal converting means comprising an interpolation means coupled to said non-linear correction means for interpolating the band-compressed television signal to restore the high-definition television signal, and a scanning line density converting means for changing the number of scanning lines of the high-definition television signal restored by said interpolation means to the number of scanning lines of the conventional television signal; an inverse matrix means coupled to said signal converting means for producing three primary color signals from an output signal of said scanning line density converting means; and a picture display means coupled to said inverse matrix means for displaying the three primary signals; wherein said non-linear level correction means corrects for a difference between said non-linear level expansion characteristic and a non-linear electro-optic conversion characteristic of said picture display means.
Claim 3
Dependent Claim
60 words
An apparatus according to claim 1, wherein said non-linear level correction means comprises: a means for producing a predetermined correction value representing a synthesis of said non-linear electro-optic conversion characteristic of said picture display means and an inverse characteristic to said non-linear level expansion characteristic; and a means for adding said predetermined correction value to the transmitted band-compressed television signal.
Claim 4
Dependent Claim
85 words
An apparatus according to claim 1, wherein said non-linear level correction means comprises: a signal level detection means for detecting a level of the transmitted band-compressed television signal; a means responsive to a detection result of said level detection means for producing a predetermined correction value representing a synthesis of said non-linear electro-optic conversion characteristic of said picture display means and an inverse characteristic to said non-linear level expansion characteristic; and a means for adding said predetermined correction value to the transmitted band-compressed television signal.
Claim 5
Dependent Claim
251 words
A television signal converting apparatus for converting a high-definition television signal having a larger number of scanning lines than that of a conventional television signal into the conventional television signal, said high definition television signal having been bandwidth compressed and processed so as to have a non-linear level expansion characteristic at a transmission side and transmitted through a transmission path from the transmission side in the form of a band-compressed television signal, said apparatus comprising: a non-linear correction means for correcting a signal level of the transmitted band-compressed television signal based on a predetermined non-linear characteristic; a signal converting means for converting an output signal of said non-linear correction means to the conventional television signal, said signal converting means comprising an interpolation means coupled to said non-linear correction means for interpolating the band-compressed television signal to restore the high-definition television signal, and a scanning line density converting means for changing the number of scanning lines of the high-definition television signal restored by said interpolation means to the number of scanning lines of the conventional television signal; an inverse matrix means coupled to said signal converting means for producing three primary color signals from an output signal of said scanning line density converting means; and a picture display means coupled to said inverse matrix means for displaying the three primary signals; wherein said non-linear level correction means corrects a transmission gamma of the transmission path and a gamma of said picture display means at the same time by one predetermined correction value.
Claim 6
Dependent Claim
251 words
A television signal converting apparatus for converting a high-definition television signal having a larger number of scanning lines than that of a conventional television signal into the conventional television signal, said high definition television signal having been bandwidth compressed and processed so as to have a non-linear level expansion characteristic at a transmission side and transmitted through a transmission path from the transmission side in the form of a band-compressed television signal, said apparatus comprising: a non-linear correction means for correcting a signal level of the transmitted band-compressed television signal based on a predetermined non-linear characteristic; a signal converting means for converting an output signal of said non-linear correction means to the conventional television signal, said signal converting means comprising an interpolation means coupled to said non-linear correction means for interpolating the band-compressed television signal to restore the high-definition television signal, and a scanning line density converting means for changing the number of scanning lines of the high-definition television signal restored by said interpolation means to the number of scanning lines of the conventional television signal; an inverse matrix means coupled to said signal converting means for producing three primary color signals from an output signal of said scanning line density converting means; and a picture display means coupled to said inverse matrix means for displaying the three primary signals; wherein said non-linear level correction means corrects a transmission gamma of the transmission path and a gamma of said picture display means at the same time by one predetermined correction value.
Claim 7
Dependent Claim
52 words
An apparatus according to claim 4, wherein said non-linear level correction means comprises: a means for producing a predetermined correction value representing a synthesis of an inverse transmission gamma and the gamma of said picture display means; and a means for adding said predetermined correction value to the transmitted band-compressed television signal.
Claim 8
Dependent Claim
78 words
An apparatus according to claim 4, wherein said non-linear level correction means comprises: a signal level detection means for detecting a level of the transmitted band-compressed television signal; a means responsive to a detection result by said signal level detection means for producing a predetermined correction value representing a synthesis of a transmission inverse gamma and the gamma of said picture display means; and a means for adding said predetermined correction value to the transmitted band-compressed television signal.
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) | 1997-05-09 | 1997-11-08 | 1998-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-09 | 2001-11-08 | 2002-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-09 | 2005-11-08 | 2006-05-10 | $7700.00 | Window Closed / Lapsed |