Patent US6028398A successfully refreshed from Google Patents.
US6028398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer
Assignee: Panasonic Photo and Lighting Co Ltd
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Filing: 1996-08-15
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Granted: 2000-02-22
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Expires: 2016-08-15
Abstract
Abstract An AC driving signal of a frequency in the vicinity of the resonance frequency of a piezoelectric transformer is generated by a variable oscillation circuit and the waveform of the output signal of the variable oscillation circuit is shaped so as to be substantially sinusoidal by a waveform shaping circuit and the output of the waveform shaping circuit is subjected by a driving circuit to current amplification or voltage amplification so as to be amplified to a level sufficient for driving the piezoelectric transformer and the output of the driving circuit is subjected to current limitation, and then input to the piezoelectric transformer and the output signal of the transformer is applied to a cold cathode fluorescent lamp so that the cold cathode fluorescent lamp is lit and even if the impedance of the cold cathode fluorescent lamp decreases, the piezoelectric transformer cannot supply a large current.
Inventors
- 👤 Osamu Kawasaki
- 👤 Hiroshi Iwata
- 👤 Kazuou Murata
- 👤 Hiroshi Makino
- 👤 Wataru Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:39
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2821; H05B41/2822; Y; Y10; Y10S; Y10S315/00; Y10S315/05; Y10S315/07
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
88 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode and an output electrode are disposed on a piezoelectric element; and a cold cathode fluorescent lamp, wherein a resistor having a value sufficient to suppress fluctuation of said alternating-current driving signal is connected in series between an output of said amplifying circuit and said input electrode of said piezoelectric transformer.
Claim 2
Dependent Claim
88 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode and an output electrode are disposed on a piezoelectric element; and a cold cathode fluorescent lamp, wherein a resistor having a value sufficient to suppress fluctuation of said alternating-current driving signal is connected in series between an output of said amplifying circuit and said input electrode of said piezoelectric transformer.
Claim 3
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 1, wherein the resistor has a value of about 5% to 20% of an input impedance of said piezoelectric transformer.
Claim 4
Dependent Claim
135 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer which an input electrode and an output electrode are disposed on a piezoelectric element; and a cold cathode fluorescent lamp, wherein said driving circuit comprises a current amplifying circuit and a step-up transformer, and a resistor or an inductance is connected in series between an output terminal of said step-up transformer and the input electrode, said resistor or said inductance having an impedance of about 5% to 20% of an input impedance of said piezoelectric transformer to suppress fluctuation of said alternating-current driving signal said capacitor having a capacitance value that is balanced to an output capacitance value of said piezoelectric transformer.
Claim 5
Dependent Claim
135 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer which an input electrode and an output electrode are disposed on a piezoelectric element; and a cold cathode fluorescent lamp, wherein said driving circuit comprises a current amplifying circuit and a step-up transformer, and a resistor or an inductance is connected in series between an output terminal of said step-up transformer and the input electrode, said resistor or said inductance having an impedance of about 5% to 20% of an input impedance of said piezoelectric transformer to suppress fluctuation of said alternating-current driving signal said capacitor having a capacitance value that is balanced to an output capacitance value of said piezoelectric transformer.
Claim 6
Dependent Claim
91 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an two input electrode and an two output electrode are disposed on a piezoelectric element; and a cold cathode fluorescent lamp, wherein a capacitor is connected in series to a ground side of said cold cathode fluorescent lamp, said capacitor having a capacitance value that is balanced to an output capacitance value of said piezoelectric transformer.
Claim 7
Dependent Claim
91 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an two input electrode and an two output electrode are disposed on a piezoelectric element; and a cold cathode fluorescent lamp, wherein a capacitor is connected in series to a ground side of said cold cathode fluorescent lamp, said capacitor having a capacitance value that is balanced to an output capacitance value of said piezoelectric transformer.
Claim 8
Dependent Claim
38 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 4, wherein the capacitor has a value which is about 0.2 to 2 times as large as an output capacitance of said piezoelectric transformer.
Claim 9
Dependent Claim
103 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which two input electrodes and two output electrodes are disposed on a rectangular plate of a piezoelectric element; and a cold cathode fluorescent lamp, wherein (a) said input electrodes are polarized in a thickness direction of said rectangular plate and said output electrodes are polarized in a longitudinal direction of said rectangular plate; and (b) said output electrodes are connected to said cold cathode fluorescent lamp providing balanced outputs.
Claim 10
Dependent Claim
103 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which two input electrodes and two output electrodes are disposed on a rectangular plate of a piezoelectric element; and a cold cathode fluorescent lamp, wherein (a) said input electrodes are polarized in a thickness direction of said rectangular plate and said output electrodes are polarized in a longitudinal direction of said rectangular plate; and (b) said output electrodes are connected to said cold cathode fluorescent lamp providing balanced outputs.
Claim 11
Dependent Claim
42 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 6, wherein balanced outputs are taken out from both ends by longitudinally oscillating said piezoelectric transformer, and said cold cathode fluorescent lamp is connected to said balanced outputs.
Claim 12
Dependent Claim
42 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 6, wherein balanced outputs are taken out from one end by longitudinally oscillating said piezoelectric transformer, and said cold cathode fluorescent lamp is connected to said balanced outputs.
Claim 13
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 1, wherein said cold cathode fluorescent lamp driving apparatus is used in a liquid crystal display device to provide backlight.
Claim 14
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 2, wherein said cold cathode fluorescent lamp driving apparatus is used in a liquid crystal display device to provide backlight.
Claim 15
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 2, wherein said cold cathode fluorescent lamp driving apparatus is used in a liquid crystal display device to provide backlight.
Claim 16
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 3, wherein said cold cathode fluorescent lamp driving apparatus is used in a liquid crystal display device to provide backlight.
Claim 17
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 4, wherein said cold cathode fluorescent lamp driving apparatus is used in a liquid crystal display device to provide backlights.
Claim 18
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 5, wherein said cold cathode fluorescent lamp driving apparatus is used in a liquid crystal display device to provide backlight.
Claim 19
Dependent Claim
34 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer according to claim 6, wherein said cold cathode fluorescent lamp driving apparatus is used in a liquid crystal display device to provide backlight.
Claim 20
Dependent Claim
68 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode and an output electrode are disposed on a piezoelectric element; a cold cathode fluorescent lamp, and a pulsation suppression means for suppressing pulsation in the driving signal free of feedback.
Claim 21
Dependent Claim
68 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising: an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode and an output electrode are disposed on a piezoelectric element; a cold cathode fluorescent lamp, and a pulsation suppression means for suppressing pulsation in the driving signal free of feedback.
Claim 22
Dependent Claim
98 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode, an output electrode and a grounded electrode are disposed on a piezoelectric element; said input electrode coupled to said driving circuit for receiving said alternating-current driving signal; a cold cathode fluorescent lamp connected in series between said output electrode and said grounded electrode; and means for pulsation suppression free of feedback placed between said driving circuit and said grounded electrode.
Claim 23
Dependent Claim
98 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode, an output electrode and a grounded electrode are disposed on a piezoelectric element; said input electrode coupled to said driving circuit for receiving said alternating-current driving signal; a cold cathode fluorescent lamp connected in series between said output electrode and said grounded electrode; and means for pulsation suppression free of feedback placed between said driving circuit and said grounded electrode.
Claim 24
Dependent Claim
100 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode, an output electrode and a grounded electrode are disposed on a piezoelectric element; said input electrode coupled to said driving circuit for receiving said alternating-current driving signal; a cold cathode fluorescent lamp connected in series between said output electrode and said grounded electrode; and means for pulsation suppression being a resistor placed in series between said driving circuit and said input electrode.
Claim 25
Dependent Claim
100 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode, an output electrode and a grounded electrode are disposed on a piezoelectric element; said input electrode coupled to said driving circuit for receiving said alternating-current driving signal; a cold cathode fluorescent lamp connected in series between said output electrode and said grounded electrode; and means for pulsation suppression being a resistor placed in series between said driving circuit and said input electrode.
Claim 26
Dependent Claim
100 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode, an output electrode and a grounded electrode are disposed on a piezoelectric element; said input electrode coupled to said driving circuit for receiving said alternating-current driving signal; a cold cathode fluorescent lamp connected in series between said output electrode and said grounded electrode; and means for pulsation suppression being a resistor placed in series between said output electrode and said fluorescent lamp.
Claim 27
Dependent Claim
100 words
A cold cathode fluorescent lamp driving apparatus using a piezoelectric transformer, comprising an oscillation circuit which generates an alternating-current driving signal; a driving circuit which amplifies said alternating-current driving signal; a piezoelectric transformer in which an input electrode, an output electrode and a grounded electrode are disposed on a piezoelectric element; said input electrode coupled to said driving circuit for receiving said alternating-current driving signal; a cold cathode fluorescent lamp connected in series between said output electrode and said grounded electrode; and means for pulsation suppression being a resistor placed in series between said output electrode and said fluorescent lamp.
Claim 28
Dependent Claim
31 words
The cold cathode fluorescent lamp driving apparatus according to claim 17 wherein said means for pulsation suppression is a capacitor placed in series between said fluorescent lamp and said grounded electrode.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2003-02-21 | 2003-08-23 | 2004-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-02-21 | 2007-08-23 | 2008-02-22 | $3760.00 | Window Closed / Lapsed |
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