Patent US5019749A successfully refreshed from Google Patents.
US5019749A
Expired / Lapsed
US
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Back-light device for a video display apparatus
Assignee: Seiko Epson Corp
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Filing: 1989-05-03
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Granted: 1991-05-28
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Expires: 2009-05-03
Abstract
Abstract A back-light device increases the level of luminance produced by a fluorescent lamp at low and high ambient temperatures by increasing the ballast capacitance at these temperatures. The ballast capacitor can include one or more capacitors made from ceramic or the like. The back-light device can be used with different types of video display apparatuses which employ a transmission-type video display plate.
Inventors
- 👤 Norio Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:45
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2821; H05B41/36; H05B41/38; H05B41/39; H05B41/392; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 64
Claim 1
Independent Claim
77 words
A back-light device, comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures which are between about -20° C. and +10° C.; and ballast means for controlling the level of luminance produced by the light source means and which is characterized by a capacitance-ambient temperature curve having a substantially negative slope at temperatures between about -20° C. and +10° C.
Claim 2
Dependent Claim
77 words
A back-light device, comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures which are between about -20° C. and +10° C.; and ballast means for controlling the level of luminance produced by the light source means and which is characterized by a capacitance-ambient temperature curve having a substantially negative slope at temperatures between about -20° C. and +10° C.
Claim 3
Dependent Claim
15 words
The back-light device of claim 1, wherein the light source means is a fluorescent lamp.
Claim 4
Dependent Claim
14 words
The back-light device of claim 2, wherein the fluorescent lamp is a cold-cathode type.
Claim 5
Dependent Claim
14 words
The back-light device of claim 2, wherein the fluorescent lamp is a hot-cathode type.
Claim 6
Dependent Claim
19 words
The back-light device of claim 1, wherein the ballast means and light source means are electrically connected in series.
Claim 7
Dependent Claim
21 words
The back-light device of claim 1, further including transformer means for producing an alternating current to power the light source means.
Claim 8
Dependent Claim
21 words
The back-light device of claim 5, further including transformer means for producing an alternating current to power the light source means.
Claim 9
Dependent Claim
21 words
The back-light device of claim 7, wherein the transformer means includes a winding electrically connected in series with the ballast means.
Claim 10
Dependent Claim
16 words
The back-light device of claim 6, further including a push-pull oscillator for driving the transformer means.
Claim 11
Dependent Claim
16 words
The back-light device of claim 8, further including a push-pull oscillator for driving the transformer means.
Claim 12
Dependent Claim
75 words
A back-light device, comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures between -20° C. and +10° C.; and ballast means for controlling the level of luminance produced by the light source means and which is characterized by a impedance-ambient temperature curve having a substantially positive slope at temperatures which are between -20° C. and +10° C.
Claim 13
Dependent Claim
75 words
A back-light device, comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures between -20° C. and +10° C.; and ballast means for controlling the level of luminance produced by the light source means and which is characterized by a impedance-ambient temperature curve having a substantially positive slope at temperatures which are between -20° C. and +10° C.
Claim 14
Dependent Claim
15 words
The back-light device of claim 11, wherein the light source means is a fluorescent lamp.
Claim 15
Dependent Claim
14 words
The back-light device of claim 12, wherein the fluorescent lamp is a cold-cathode type.
Claim 16
Dependent Claim
14 words
The back-light device of claim 12, wherein the fluorescent lamp is a hot-cathode type.
Claim 17
Dependent Claim
13 words
The back-light device of claim 11, wherein the ballast means is a thermistor.
Claim 18
Dependent Claim
13 words
The back-light device of claim 11, wherein the ballast means is an inductor.
Claim 19
Dependent Claim
19 words
The back-light device of claim 11, wherein the ballast means and light source means are electrically connected in series.
Claim 20
Dependent Claim
19 words
The back-light device of claim 12, wherein the ballast means and light source means are electrically connected in series.
Claim 21
Dependent Claim
21 words
The back-light device of claim 11, further including transformer means for producing an alternating current to power the light source means.
Claim 22
Dependent Claim
21 words
The back-light device of claim 17, further including transformer means for producing an alternating current to power the light source means.
Claim 23
Dependent Claim
21 words
The back-light device of claim 20, wherein the transformer means includes a winding electrically connected in series with the ballast means.
Claim 24
Dependent Claim
16 words
The back-light device of claim 21, further including a push-pull oscillator for driving the transformer means.
Claim 25
Dependent Claim
16 words
The back-light device of claim 1, wherein the ballast means includes at least one ceramic capacitor.
Claim 26
Dependent Claim
19 words
The back-light device of claim 1, wherein the ballast means includes more than one capacitor electrically connected in parallel.
Claim 27
Dependent Claim
19 words
The back-light device of claim 1, wherein the ballast means includes more than one capacitor electrically connected in series.
Claim 28
Dependent Claim
15 words
The back-light device of claim 24, wherein at least one capacitor is a ceramic capacitor.
Claim 29
Dependent Claim
15 words
The back-light device of claim 25, wherein at least one capacitor is a ceramic capacitor.
Claim 30
Dependent Claim
99 words
A video display apparatus including back-light device, said apparatus comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures between about -20° C. and +10° C.; ballast means for controlling the level of luminance produced by the light source means and which is characterized by a capacitance-ambient temperature curve having a substantially negative slope at temperatures which are between about -20° C. and +10° C.; and display means lit by the luminance of said light source means for display of an image.
Claim 31
Dependent Claim
99 words
A video display apparatus including back-light device, said apparatus comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures between about -20° C. and +10° C.; ballast means for controlling the level of luminance produced by the light source means and which is characterized by a capacitance-ambient temperature curve having a substantially negative slope at temperatures which are between about -20° C. and +10° C.; and display means lit by the luminance of said light source means for display of an image.
Claim 32
Dependent Claim
16 words
The video display apparatus of claim 28, wherein the light source means is a fluorescent lamp.
Claim 33
Dependent Claim
15 words
The video display apparatus of claim 29, wherein the fluorescent lamp is a cold-cathode type.
Claim 34
Dependent Claim
15 words
The video display apparatus of claim 29, wherein the fluorescent lamp is a hot-cathode type.
Claim 35
Dependent Claim
20 words
The video display apparatus of claim 28, wherein the ballast means and light source means are electrically connected in series.
Claim 36
Dependent Claim
22 words
The video display apparatus of claim 28, further including transformer means for producing an alternating current to power the light source means.
Claim 37
Dependent Claim
22 words
The video display apparatus of claim 33, further including transformer means for producing an alternating current to power the light source means.
Claim 38
Dependent Claim
22 words
The video display apparatus of claim 34, wherein the transformer means includes a winding electrically connected in series with the ballast means.
Claim 39
Dependent Claim
17 words
The video display apparatus of claim 33, further including a push-pull oscillator for driving the transformer means.
Claim 40
Dependent Claim
17 words
The video display apparatus of claim 35, further including a push-pull oscillator for driving the transformer means.
Claim 41
Dependent Claim
98 words
A video display apparatus including a back-light device, said apparatus comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures between about -20° C. and +10° C.; ballast means for controlling the level of luminance produced by the light source means and which is characterized by an impedance-ambient temperature curve having a substantially positive slope at temperatures between about -20° C. and +10° C.; and display means lit by the luminance of said light source means for display of an image.
Claim 42
Dependent Claim
98 words
A video display apparatus including a back-light device, said apparatus comprising: light source means for producing a varying level of luminance and which is characterized by a luminance-ambient temperature curve having a substantially positive slope at temperatures between about -20° C. and +10° C.; ballast means for controlling the level of luminance produced by the light source means and which is characterized by an impedance-ambient temperature curve having a substantially positive slope at temperatures between about -20° C. and +10° C.; and display means lit by the luminance of said light source means for display of an image.
Claim 43
Dependent Claim
16 words
The video display apparatus of claim 38, wherein the light source means is a fluorescent lamp.
Claim 44
Dependent Claim
15 words
The video display apparatus of claim 39, wherein the fluorescent lamp is a cold-cathode type.
Claim 45
Dependent Claim
15 words
The video display apparatus of claim 39, wherein the fluorescent lamp is a hot-cathode type.
Claim 46
Dependent Claim
14 words
The video display apparatus of claim 38, wherein the ballast means is a thermistor.
Claim 47
Dependent Claim
14 words
The video display apparatus of claim 38, wherein the ballast means is an inductor.
Claim 48
Dependent Claim
20 words
The video display apparatus of claim 38, wherein the ballast means and light source means are electrically connected in series.
Claim 49
Dependent Claim
20 words
The video display apparatus of claim 39, wherein the ballast means and light source means are electrically connected in series.
Claim 50
Dependent Claim
22 words
The video display apparatus of claim 38, further including transformer means for producing an alternating current to power the light source means.
Claim 51
Dependent Claim
22 words
The video display apparatus of claim 44, further including transformer means for producing an alternating current to power the light source means.
Claim 52
Dependent Claim
22 words
The video display apparatus of claim 47, wherein the transformer means includes a winding electrically connected in series with the ballast means.
Claim 53
Dependent Claim
17 words
The video display apparatus of claim 48, further including a push-pull oscillator for driving the transformer means.
Claim 54
Dependent Claim
17 words
The video display apparatus of claim 28, wherein the ballast means includes at least one ceramic capacitor.
Claim 55
Dependent Claim
20 words
The video display apparatus of claim 28, wherein the ballast means includes more than one capacitor electrically connected in parallel.
Claim 56
Dependent Claim
20 words
The video display apparatus of claim 28, wherein the ballast means includes more than one capacitor electrically connected in series.
Claim 57
Dependent Claim
16 words
The video display apparatus of claim 51, wherein at least one capacitor is a ceramic capacitor.
Claim 58
Dependent Claim
16 words
The video display apparatus of claim 52, wherein at least one capacitor is a ceramic capacitor.
Claim 59
Dependent Claim
27 words
The back-light device of claim 1, wherein the capacitance-ambient temperature curve is further characterized by a substantially zero slope for ambient temperatures between about 40° C.-60° C.
Claim 60
Dependent Claim
26 words
The back-light device of claim 1, wherein the capacitance-ambient temperature curve is further characterized by a substantially positive slope for ambient temperatures between 40° C.-60° C.
Claim 61
Dependent Claim
24 words
The video-display apparatus of claim 28, wherein the display means includes a transmission-type video display plate which is illuminated by the light source means.
Claim 62
Dependent Claim
24 words
The video-display apparatus of claim 38, wherein the display means includes a transmission-type video display plate which is illuminated by the light source means.
Claim 63
Independent Claim
99 words
A method of illuminating the rear of a transmission-type video display plate of a video display apparatus comprising: varying the level of luminance directed toward the plate and produced by a fluorescent lamp based on the ambient temperature wherein the lamp is characterized by a luminance-ambient temperature curve having a positive slope between about -20° C. and +10° C.; and controlling the variations in luminance based on a ballast changing the flow of current supplied to the lamp wherein said ballast is characterized by a capacitance-ambient temperature curve having a negative slope between about -20° C. and +10° C.
Claim 64
Independent Claim
99 words
A method of illuminating the rear of a transmission-type video display plate of a video display apparatus comprising: varying the level of luminance directed toward the plate and produced by a fluorescent lamp based on the ambient temperature wherein the lamp is characterized by a luminance-ambient temperature curve having a positive slope between about -20° C. and +10° C.; and controlling the variations in luminance based on a ballast changing the flow of current supplied to the lamp wherein said ballast is characterized by a capacitance-ambient temperature curve having a negative slope between about -20° C. and +10° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-27 | 1994-11-26 | 1995-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-27 | 1998-11-26 | 1999-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-27 | 2002-11-26 | 2003-05-28 | $7700.00 | Window Closed / Lapsed |