1. A discharge lamp lighting apparatus for converting a direct current into an alternating current of positive-negative symmetry and supplying power to a discharge lamp, comprising:
a first resonant circuit including a first transformer, a first capacitor connected to at least one of primary and secondary windings of the first transformer, and an output end connected to a first end of the discharge lamp;
first and second switching elements connected to ends of a DC power source and configured to pass a current through the primary winding of the first transformer and the first capacitor;
a second resonant circuit including a second transformer, a second capacitor connected to at least one of primary and secondary windings of the second transformer, and an output end connected to a second end of the discharge lamp, the second resonant circuit being configured to output an alternating current whose phase is opposite to the phase of an alternating current provided by the first resonant circuit;
third and fourth switching elements connected to the ends of the DC power source and configured to pass a current through the primary winding of the second transformer and the second capacitor;
an oscillator configured to generate a triangular signal;
a first control part configured to generate a first PWM control signal according to the triangular signal from the oscillator and an error voltage between a first reference voltage and a voltage corresponding to a first current passed through the secondary winding of the first transformer, the first PWM control signal being used to turn onoff the first and second switching elements with a phase difference of about 180 degrees and a pulse width corresponding to the first current; and
a second control part configured to turn onoff the third and fourth switching elements in synchronization with the first PWM control signal and according to the triangular signal from the oscillator and an error voltage between a second reference voltage and a voltage corresponding to a second current passed through the secondary winding of the second transformer, with a phase difference of about 180 degrees and a pulse width corresponding to the second current, wherein
PWM control operations are individually carried out to generate alternating currents of opposite phases that are applied to the ends of the discharge lamp.
2. The discharge lamp lighting apparatus of claim 1, further comprising
a start-stop circuit, a soft start circuit, an output breaking circuit, and a burst dimming triangular wave oscillator those are shared by the first and second control parts, wherein:
at the start of operation of the discharge lamp lighting apparatus, the start-stop circuit and soft start circuit carry out an operation of gradually increasing the quantity of power to be supplied to the discharge lamp and supply power to the first and second control parts;
at the stoppage of operation of the discharge lamp lighting apparatus, the start-stop circuit stops power supplied to the first and second control parts;
at a burst dimming operation of the discharge lamp lighting apparatus, the burst dimming triangular wave oscillator provides the first and second control parts with a burst dimming signal so that power is intermittently supplied to the discharge lamp; and
the output breaking circuit stops supplying power to the first and second control parts as an abnormality is detected.
3. The discharge lamp lighting apparatus of claim 2, further comprising:
a current detector configured to detect the first current passed through the secondary winding of the first transformer and the second current passed through the secondary winding of the second transformer; and
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency as the first and second currents detected by the current detector are equal to or larger than respective predetermined values, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined value.
4. The discharge lamp lighting apparatus of claim 2, further comprising:
a voltage detector configured to detect a first voltage of the secondary winding of the first transformer and a second voltage of the secondary winding of the second transformer;
a current detector configured to detect the first current and second current; and
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency as the first and second currents are equal to or larger than respective predetermined currents and the first and second voltages are lower than respective predetermined voltages, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined current or any one of the first and second voltages is equal to or larger than the corresponding predetermined voltage.
5. The discharge lamp lighting apparatus of claim 1, further comprising:
a current detector configured to detect the first current passed through the secondary winding of the first transformer and the second current passed through the secondary winding of the second transformer; and
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency as the first and second currents detected by the current detector are equal to or larger than respective predetermined values, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined value.
6. The discharge lamp lighting apparatus of claim 1, further comprising:
a voltage detector configured to detect a first voltage of the secondary winding of the first transformer and a second voltage of the secondary winding of the second transformer;
a current detector configured to detect the first current and second current; and
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency as the first and second currents are equal to or larger than respective predetermined currents and the first and second voltages are lower than respective predetermined voltages, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined current or any one of the first and second voltages is equal to or larger than the corresponding predetermined voltage.
7. A semiconductor integrated circuit for controlling a plurality of switching elements that supply power to a discharge lamp, the switching elements including first and second switching elements being connected to ends of a DC power source and passing a current through a primary winding of a first transformer and a first capacitor and third and fourth switching elements being connected to the ends of the DC power source and passing a current through a primary winding of a second transformer and a second capacitor, the semiconductor integrated circuit comprising:
an oscillator configured to generate a triangular signal;
a first control part configured to generate a first PWM control signal according to the triangular signal of the oscillator and an error voltage between a first reference voltage and a voltage corresponding to a first current passed through the secondary winding of the first transformer, the first PWM control signal being used to turn onoff the first and second switching elements with a phase difference of about 180 degrees and a pulse width corresponding to the first current; and
a second control part configured to turn onoff the third and fourth switching elements in synchronization with the first PWM control signal and according to the triangular signal of the oscillator and an error voltage between a second reference voltage and a voltage corresponding to a second current passed through the secondary winding of the second transformer, with a phase difference of substantially 180 degrees and a pulse width corresponding to the second current.
8. The semiconductor integrated circuit of claim 7, further comprising
a start-stop circuit, a soft start circuit, an output breaking circuit, and a burst dimming triangular wave oscillator those are shared by the first and second control parts, wherein:
at the start of operation of a discharge lamp lighting apparatus, the start-stop circuit and soft start circuit carry out an operation of gradually increasing the quantity of power to be supplied to the discharge lamp and supply power to the first and second control parts;
at the stoppage of operation of the discharge lamp lighting apparatus, the start-stop circuit stops power supplied to the first and second control parts;
at a burst dimming operation of the discharge lamp lighting apparatus, the burst dimming triangular wave oscillator provides the first and second control parts with a burst dimming signal so that power is intermittently supplied to the discharge lamp; and
the output breaking circuit stops supplying power to the first and second control parts as an abnormality is detected.
9. The semiconductor integrated circuit of claim 8, further comprising
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency if a first current passed through the secondary winding of the first transformer connected to a first end of the discharge lamp and a second current passed through the secondary winding of the second transformer connected to a second end of the discharge lamp are equal to or larger than respective predetermined values, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined value.
10. The semiconductor integrated circuit of claim 8, further comprising:
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency as a first current passed through the secondary winding of the first transformer connected to a first end of the discharge lamp and a second current passed through the secondary winding of the second transformer connected to a second end of the discharge lamp are equal to or larger than respective predetermined values and a first voltage of the secondary winding of the first transformer and a second voltage of the secondary winding of the second transformer are lower than respective predetermined voltages, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined value and any one of the first and second voltages is equal to or larger than the corresponding predetermined value.
11. The semiconductor integrated of claim 8, further comprising:
a first burst dimming mode circuit configured to provide the first and second control parts with burst dimming signals of the same phase, the burst dimming signals being used to intermittently supply power to the discharge lamp;
a second burst dimming mode circuit configured to provide the first and second control parts with burst dimming signals with a phase difference of 180 degrees, the burst dimming signals being used to intermittently supply power to the discharge lamp; and
a burst mode switching unit configured to switch the first and second burst dimming mode circuits from one to another according to a switching signal.
12. The semiconductor integrated circuit of claim 7, further comprising
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency if a first current passed through the secondary winding of the first transformer connected to a first end of the discharge lamp and a second current passed through the secondary winding of the second transformer connected to a second end of the discharge lamp are equal to or larger than respective predetermined values, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined value.
13. The semiconductor integrated circuit of claim 7, further comprising:
a switching unit configured to set the oscillation frequency of the oscillator at a first oscillation frequency as a first current passed through the secondary winding of the first transformer connected to a first end of the discharge lamp and a second current passed through the secondary winding of the second transformer connected to a second end of the discharge lamp are equal to or larger than respective predetermined values and a first voltage of the secondary winding of the first transformer and a second voltage of the secondary winding of the second transformer are lower than respective predetermined voltages, and set the oscillation frequency of the oscillator at a second oscillation frequency that is greater than the first oscillation frequency as any one of the first and second currents is lower than the corresponding predetermined value and any one of the first and second voltages is equal to or larger than the corresponding predetermined value.
14. The semiconductor integrated circuit of claim 7, further comprising:
a first burst dimming mode circuit configured to provide the first and second control parts with burst dimming signals of the same phase, the burst dimming signals being used to intermittently supply power to the discharge lamp;
a second burst dimming mode circuit configured to provide the first and second control parts with burst dimming signals with a phase difference of 180 degrees, the burst dimming signals being used to intermittently supply power to the discharge lamp; and
a burst mode switching unit configured to switch the first and second burst dimming mode circuits from one to another according to a switching signal.
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 method of manufacturing a seamless silicon roll having a pattern, the method comprising:
preparing a pattern roll having the same size and pattern as a silicon roll to be manufactured;
manufacturing a cast by pouring cast materials around the pattern roll and curing the cast materials;
removing the cast from the pattern roll;
forming a silicon roll by disposing the central axis of a roll in the cast, pouring liquid silicon and curing the liquid silicon; and
removing the silicon roll from the cast.
2. The method of claim 1, wherein the cast materials are selected from the group consisting of liquid- or gum-type silicon, liquid- or gum-type urethane and rubbers such as natural rubber, SBR, BR, CR, NBR and EPDM.
3. The method of claim 2, wherein the cast materials comprise 0.1 to 10% by weight of a curing agent, based on the total weight of the cast materials.
4. The method of claim 2, wherein the cast materials are solvent-free.
5. The method of claim 1, wherein the manufacturing of the cast comprises:
installing molds around the pattern roll at a constant distance, pouring cast materials into a space between the molds and the pattern roll and curing the cast materials.
6. The method of claim 1, wherein the removing of the cast from the pattern roll comprises: injecting air into a space between the pattern roll and the cast to reduce a contact area between the pattern roll and the cast and separating the cast from the pattern roll.
7. The method of claim 1, wherein the forming of the silicon roll comprises:
fitting a cast and central axis into a frame having a round frame into which the cast is fit and a hole for fitting a central axis into the center of the round frame; pouring liquid silicon; and curing the liquid silicon.
8. The method of claim 1, wherein the liquid silicon is solvent-free.
9. The method of claim 8, wherein the liquid silicon comprises 3 to 30% by weight of a curing agent, based on the total weight of the liquid silicon.
10. The method of claim 1, wherein a curing temperature of the liquid silicon is room temperature.
11. The method of claim 1, further comprising: surface-modifying an inner surface of the cast after the removing of the cast from the pattern roll.
12. The method of claim 11, wherein the surface modification is performed by at least one selected from the group consisting of plasma treatment, UV-ozone treatment and corona discharge treatment.
13. A silicon roll manufactured according to the method of claim 1, wherein the silicon roll has a seamless surface.
14. The method of claim 5, further comprising: surface-modifying an inner surface of the cast after the removing of the cast from the pattern roll.
15. The method of claim 6, further comprising: surface-modifying an inner surface of the cast after the removing of the cast from the pattern roll.
16. The method of claim 7, further comprising: surface-modifying an inner surface of the cast after the removing of the cast from the pattern roll.
17. The method of claim 14, wherein the surface modification is performed by at least one selected from the group consisting of plasma treatment, UV-ozone treatment and corona discharge treatment.
18. The method of claim 15, wherein the surface modification is performed by at least one selected from the group consisting of plasma treatment, UV-ozone treatment and corona discharge treatment.
19. The method of claim 16, wherein the surface modification is performed by at least one selected from the group consisting of plasma treatment, UV-ozone treatment and corona discharge treatment.