We claim:
1. A multi-pole, conductive liquid-based switch device, comprising:
a passage, the passage being elongate and having a length;
a first cavity and a second cavity;
at least four electrodes disposed along the length of the passage;
channels, one fewer in number than the electrodes, extending from the passage and interleaved with the electrodes along the length of the passage, the channels being numbered in order from an end of the passage, odd-numbered ones of the channels extending to the first cavity, even-numbered ones of the channels extending to the second cavity;
non-conductive fluid located the cavities; and
conductive liquid located in the passage.
2. The switch device of claim 1, additionally comprising means for selectively heating the non-conductive fluid in each of the cavities.
3. The switch device of claim 1, additionally comprising a ground plane in adjacent the passage and the electrodes.
4. The switch device of claim 3, in which the passage and the electrodes are structured to constitute at least part of a transmission line.
5. The switch device of claim 1, in which:
the electrodes number no more than four and are ordinally numbered from the end of the passage;
the switch device additionally comprises:
an electrical attenuator connected between a first and a fourth of the electrodes, and
signal connectors electrically connected to a second and a third of the electrodes.
6. The switch device of claim 1, in which:
the electrodes number no more than five and are ordinally numbered from the end of the passage;
the switch device additionally comprises:
a ground connection to a first and a fifth of the electrodes,
a signal connection of a first type electrically connected to a third of the electrodes, and
a signal connection of a second type electrically connected to each of a second of the electrodes and a fourth of the electrodes.
7. The switch device of claim 6, in which the ground connection to the first and fifth electrodes includes a termination resistor.
8. The switch device of claim 1, additionally comprising a latching structure associated with each one of the channels.
9. The switch device of claim 8, in which each latching structure includes energy barriers that hold apart free surfaces of the conductive liquid.
10. The switch device of claim 9, in which each energy barrier includes a high surface energy portion at one of the channels and a low surface energy portion between the one of the channels and an adjacent one of the electrodes, a free surface of the conductive liquid having a higher surface energy in the high surface energy portion than in the low surface energy.
11. The switch device of claim 10, in which the electrodes are of a material having a higher wettability with respect to the conductive liquid than the passage and provide the low surface energy portion.
12. The switch device of claim 1, in which:
the channels each have a length; and
the channels have smaller cross-sectional dimensions than the passage over at least part of their length.
13. The switch device of claim 12, additionally comprising means for selectively heating the non-conductive fluid in each of the cavities.
14. The switch device of claim 12, additionally comprising a ground plane adjacent the passage and the electrodes.
15. The switch device of claim 14, in which the passage and the electrodes are structured to constitute at least part of a transmission line.
16. The switch device of claim 12, in which:
the electrodes number no more than four and are ordinally numbered from the end of the passage;
the switch device additionally comprises:
an electrical attenuator connected between a first and a fourth of the electrodes, and
signal connectors electrically connected to a second and a third of the electrodes.
17. The switch device of claim 12, in which:
the electrodes number no more than five and are ordinally numbered from the end of the passage;
the switch device additionally comprises:
a ground connection to a first and a fifth of the electrodes,
a signal connection of a first type electrically connected to a third of the electrodes, and
signal connection of a second type electrically connected to each of a second of the electrodes and a fourth of the electrodes.
18. The switch device of claim 17, in which the ground connection to the first and fifth electrodes includes a termination resistor.
19. The switch device of claim 12, additionally comprising a latching structure associated with each one of the channels.
20. The switch device of claim 19, in which each latching structure includes energy barriers that hold apart free surfaces of the conductive liquid.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A driving device for a discharge lamp, comprising:
an alternating current supply section configured to supply two electrodes of the discharge lamp with an alternating current, the alternating current comprising a plurality of modulation periods with each modulation period including a highest frequency term and a lowest frequency term; and
a frequency switching section configured to vary a frequency of the alternating current supplied by the alternating current supply section non-monotonically between the highest frequency term and the lowest frequency term of the modulation period in response to a predetermined condition being satisfied.
2. The driving device according to claim 1, further including
a memory in which a predetermined reference value is stored and
wherein
the two electrodes are supplied with a predetermined electrical power,
the predetermined condition is based on a lamp voltage between the two electrodes, and
the frequency switching section varies the frequency non-monotonically in response to the lamp voltage exceeding the reference value.
3. The driving device according to claim 2, wherein
a predetermined upper threshold value that is larger than the reference value is stored in the memory,
the each modulation period includes a plurality of terms including the highest frequency term, the lowest frequency term and at least one intermediate frequency term between the highest frequency term and the lowest frequency term,
the variation in the frequency between the two temporally consecutive terms in the modulation period when the frequency switching section varies the frequency in response to the lamp voltage exceeding the upper threshold value is larger than the variation in the frequency between the two temporally consecutive terms in the modulation period when the frequency switching section varies the frequency in response to the lamp voltage falling below the threshold voltage.
4. The driving device according to claim 2, wherein the difference in the frequency between the highest frequency term and the lowest frequency term in the modulation period increases as the lamp voltage increases.
5. The driving device according to claim 2, wherein the frequency of the alternating current in the modulation period is varied monitonically when the lamp voltage falls below the reference value.
6. The driving device according to claim 2, wherein
a predetermined lower threshold value that is lower than the reference value is stored in the memory,
the variation in the frequency between the highest frequency term and the lowest frequency term in the modulation period when the frequency switching section varies the frequency in response to the lamp voltage underrunning the lower threshold value is narrower than the variation in the frequency between the highest frequency term and the lower frequency term in the modulation period when the frequency switching section varies the frequency in response to the lamp voltage exceeding the lower threshold value.
7. The driving device according to claim 6, wherein the frequency in the highest frequency term when the lamp voltage underruns the lower threshold value is adjusted lower than the frequency in the highest frequency term when the lamp voltage exceeds the lower threshold value.
8. The driving device according to claim 6, wherein the frequency in the lowest frequency term in the modulation period when the lamp voltage underruns the lower threshold value is adjusted higher than the frequency in the lowest frequency term in the modulation period when the lamp voltage exceeds the lower threshold value.
9. The driving device according to claim 1, wherein the predetermined condition is based on a deterioration state of the discharge lamp, and the frequency switching section varies the frequency non-monotonically in response to a deterioration of the discharge lamp.
10. The driving device according to claim 1, wherein each modulation period is comprised of a plurality of switching periods having non-rectangular waveforms, each switching period having at least one anode period and one cathode period and an absolute value of the alternating current for a posterior end of each of the anode periods and cathode periods is larger than an absolute value of an average alternating current for each of the anode periods and cathode periods, respectively.
11. A driving device for a discharge lamp, comprising:
an alternating current supply section configured to supply two electrodes of the discharge lamp with an alternating current having a frequency, the alternating current comprising a plurality of modulation periods with each modulation period including a plurality of terms; and
a frequency switching section configured to vary the frequency of the alternating current supplied by the alternating current supply section,
wherein the frequency switching section varies, in response to a predetermined condition being satisfied, the frequency of the modulation periods such that the variation in the frequency between two temporally consecutive terms in the modulation period is larger than the variation in the frequency between two temporally consecutive terms in the modulation period when the predetermined condition fails to be satisfied.
12. A light source device comprising:
a discharge lamp;
an alternating current supply section configured to supply two electrodes of the discharge lamp with an alternating current to light the discharge lamp, the alternating current comprising a plurality of modulation periods with each modulation period including a highest frequency term and a lowest frequency term; and
a frequency switching section configured to vary a frequency of the alternating current supplied by the alternating current supply section non-monotonically between the highest frequency term and the lowest frequency term in response to a predetermined condition being satisfied.
13. An image display apparatus comprising:
a discharge lamp as alight source configured to display an image;
an alternating current supply section configured to supply two electrodes of the discharge lamp with an alternating current to light the discharge lamp, the alternating current comprising a plurality of modulation periods with each modulation period including a highest frequency term and a lowest frequency term; and
a frequency switching section configured to vary a frequency of the alternating current supplied by the alternating current supply section non-monotonically between the highest frequency term and the lowest frequency term in response to a predetermined condition being satisfied.
14. A driving method for a discharge lamp comprising:
supplying an alternating current to two electrodes of the discharge lamp, the alternating current comprising a plurality of modulation periods with each modulation period including a highest frequency term and a lowest frequency term; and
varying the frequency of the alternating current non-monotonically between the highest frequency term and the lowest frequency term of the modulation periods in response to a predetermined condition being satisfied.