Patent US4468313A successfully refreshed from Google Patents.
Patent US5384516A successfully refreshed from Google Patents.
US5384516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information processing apparatus including a control circuit for controlling a liquid crystal display illumination based on whether illuminatio power is being supplied from an AC power source or from a battery
Assignee: Hitachi Microcomputer System Ltd
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Filing: 1992-11-02
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Granted: 1995-01-24
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Expires: 2012-11-02
Abstract
Abstract An information processing apparatus employs a liquid crystal display and a fluorescent lamp for backlighting the screen of the liquid crystal display. A lighting circuit for supplying alternating current lighting power to the fluorescent lamp receives input power from either a commercial alternating current power source or from a direct current battery. The level of the lighting power supplied to the fluorescent lamp is determined based upon a determination of whether the input power is being supplied from the commercial power source or from the battery.
Inventors
- 👤 Kenji Kawabata
- 👤 Soichiro Ogawa
- 👤 Susumu Iijima
- 👤 Kunio Seki
- 👤 Hirotaka Mochizuki
- 👤 Makoto Goto
- 👤 Ryuichi Ikeda
- 👤 Motohiro Sugino
- 👤 Kenichi Onda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:20
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/36; H05B41/38; H05B41/39; H05B41/392; H05B41/3921; H05B41/3925; G; G06; G06F; G06F3/00; G06F3/14; G06F3/147; G06F1/00; G06F1/26; G06F1/32; H05B41/26; H05B41/28; H05B41/282; H05B41/285; H05B41/2851; H05B41/2853; Y; Y02; Y02B; Y02B20/00
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
182 words
An information processing apparatus employing a liquid crystal display, comprising: a fluorescent lamp for backlighting a liquid crystal display screen; a lighting circuit for supplying ac lighting power to the fluorescent lamp; first power supply means for supplying input power to the lighting circuit from a commercial ac power source; second power supply means for supplying input power to the lighting circuit from a dc battery when the lighting circuit is not being supplied with the input power from the first power supply means; detection means for detecting whether the input power of the lighting circuit is being supplied from the first power supply means or from the second power supply means; and control means for controlling the level of the lighting power supplied to the fluorescent lamp in response to a detection signal outputted by the detection means, the level of the lighting power being larger when the input power of the lighting circuit is being supplied from the first power supply means than when the input power of the lighting circuit is being supplied from the second power supply means.
Claim 2
Dependent Claim
182 words
An information processing apparatus employing a liquid crystal display, comprising: a fluorescent lamp for backlighting a liquid crystal display screen; a lighting circuit for supplying ac lighting power to the fluorescent lamp; first power supply means for supplying input power to the lighting circuit from a commercial ac power source; second power supply means for supplying input power to the lighting circuit from a dc battery when the lighting circuit is not being supplied with the input power from the first power supply means; detection means for detecting whether the input power of the lighting circuit is being supplied from the first power supply means or from the second power supply means; and control means for controlling the level of the lighting power supplied to the fluorescent lamp in response to a detection signal outputted by the detection means, the level of the lighting power being larger when the input power of the lighting circuit is being supplied from the first power supply means than when the input power of the lighting circuit is being supplied from the second power supply means.
Claim 3
Dependent Claim
57 words
An information processing apparatus according to claim 1, further comprising: a liquid crystal display; and an information processing unit having a keyboard, internal semiconductor electronic circuits and a lid unit joined to the information processing unit; wherein the liquid crystal display, the fluorescent lamp, the lighting circuit and the control means are provided in the lid unit.
Claim 4
Dependent Claim
17 words
An information processing apparatus according to claim 1, further comprising a rechargeable battery as the dc battery.
Claim 5
Dependent Claim
41 words
An information processing apparatus according to claim 1, wherein the first power supply means comprises rectifier means for rectifying the input power from the commercial ac power source, and for outputting dc output power to be supplied to the lighting circuit.
Claim 6
Dependent Claim
40 words
An information processing apparatus according to claim 4, further comprising: a rechargeable battery as the dc battery; wherein the first power supply means further comprises means for charging the dc battery with the dc output power of the rectifier means.
Claim 7
Dependent Claim
101 words
An information processing apparatus according to claim 1, wherein the detection means comprises means for comparing the input voltage of the lighting circuit with a predetermined reference voltage, means for outputting a first detection signal which shows that the lighting circuit is being supplied from the first power supply means when the input voltage of the lighting circuit is higher than the reference voltage, and means for outputting a second detection signal which shows that the lighting circuit is being supplied from the second power supply means when the input voltage of the lighting circuit is lower than the reference voltage.
Claim 8
Dependent Claim
77 words
An information processing apparatus according to claim 6, wherein the control means comprises means for decreasing the frequency of the lighting power supplied to the fluorescent lamp to a first frequency level when the first detection signal is outputted, and means for increasing the frequency of the lighting power supplied to the fluorescent lamp to a second frequency level when the second detection signal is outputted, said second frequency level being greater than said first frequency level.
Claim 9
Dependent Claim
84 words
An information processing apparatus according to claim 1, further comprising means for detecting an increase of the input voltage of the lighting circuit beyond a predetermined upper limit and for detecting a decrease of the input voltage of the lighting circuit below a predetermined lower limit, and means for stopping operation of the lighting circuit when the input voltage increases beyond the predetermined upper limit and for stopping the operation of the lighting circuit when the input voltage decreases below the predetermined lower limit.
Claim 10
Dependent Claim
43 words
An information processing apparatus according to claim 8, further comprising means for restarting the operation of the lighting circuit when the input voltage of the lighting circuit is restored into a range defined by the predetermined upper limit and the predetermined lower limit.
Claim 11
Dependent Claim
47 words
An information processing apparatus according to claim 1, further comprising: means for detecting the input current flowing into the lighting circuit; and means for stopping operation of the lighting circuit upon an increase of the input current flowing into the lighting circuit beyond a predetermined current value.
Claim 12
Dependent Claim
37 words
An information processing apparatus according to claim 10, further comprising means for restarting the operation of the lighting circuit when a predetermined time interval has been passed after the operation of the lighting circuit has been stopped.
Claim 13
Dependent Claim
154 words
An information processing apparatus employing a liquid crystal display device, comprising: a fluorescent lamp for backlighting the screen of the liquid crystal display device; a lighting circuit for supplying ac lighting power to the fluorescent lamp; power supply means for selectively supplying input power to the lighting circuit from one of a commercial ac power source and a dc battery; detection means for detecting whether the input power of the lighting circuit is being supplied from the commercial ac power source or from the dc battery; and control means for controlling the level of the lighting power supplied to the fluorescent lamp in response to a detection signal outputted from the detection means, the level of the lighting power being larger when the input power of the lighting circuit is being supplied from the commercial ac power source than when the input power of the lighting circuit is being supplied from the dc battery.
Claim 14
Dependent Claim
154 words
An information processing apparatus employing a liquid crystal display device, comprising: a fluorescent lamp for backlighting the screen of the liquid crystal display device; a lighting circuit for supplying ac lighting power to the fluorescent lamp; power supply means for selectively supplying input power to the lighting circuit from one of a commercial ac power source and a dc battery; detection means for detecting whether the input power of the lighting circuit is being supplied from the commercial ac power source or from the dc battery; and control means for controlling the level of the lighting power supplied to the fluorescent lamp in response to a detection signal outputted from the detection means, the level of the lighting power being larger when the input power of the lighting circuit is being supplied from the commercial ac power source than when the input power of the lighting circuit is being supplied from the dc battery.
Claim 15
Dependent Claim
17 words
An information processing apparatus according to claim 12, further comprising a rechargeable battery as the dc battery.
Claim 16
Dependent Claim
99 words
An information processing apparatus according to claim 12, wherein the detection means comprises means for comparing the input voltage of the lighting circuit with a predetermined reference voltage, means for outputting a first detection signal which shows that the lighting circuit is being supplied from the commercial ac power source when the input voltage of the lighting circuit is higher than the reference voltage, and means for outputting a second detection signal which shows that the lighting circuit is being supplied from the dc battery when the input voltage of the lighting circuit is lower than the reference voltage.
Claim 17
Dependent Claim
77 words
An information processing apparatus according to claim 14, wherein the control means comprises means for lowering the frequency of the lighting power supplied to the fluorescent lamp to a first frequency level when the first detection signal is outputted, and means for increasing the frequency of the lighting power supplied to the fluorescent lamp to a second frequency level when the second detection signal is outputted, the second frequency level being greater than the first frequency level.
Claim 18
Dependent Claim
84 words
An information processing apparatus according to claim 12, further comprising means for detecting an increase of the input voltage of the lighting circuit beyond a predetermined upper limit and for detecting a decrease of the input voltage of the lighting circuit below a predetermined lower limit, and means for stopping operation of the lighting circuit when the input voltage increases beyond the predetermined upper limit and for stopping the operation of the lighting circuit when the input voltage decreases below the predetermined lower limit.
Claim 19
Dependent Claim
43 words
An information processing apparatus according to claim 16, further comprising means for restarting the operation of the lighting circuit when the input voltage of the lighting circuit is restored into a range defined by the predetermined upper limit and the predetermined lower limit.
Claim 20
Dependent Claim
47 words
An information processing apparatus according to claim 12, further comprising: means for detecting the input current flowing into the lighting circuit; and means for stopping operation of the lighting circuit upon an increase of the input current flowing into the lighting circuit beyond a predetermined current value.
Claim 21
Dependent Claim
37 words
An information processing apparatus according to claim 18, further comprising means for restarting the operation of the lighting circuit when a predetermined time interval has been passed after the operation of the lighting circuit has been stopped.
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) | 1998-01-23 | 1998-07-25 | 1999-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-23 | 2002-07-25 | 2003-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-23 | 2006-07-25 | 2007-01-24 | $7700.00 | Window Closed / Lapsed |