1. A gate driving circuit for a driving target device operable with a DC power source, comprising:
a reactor having a set inductance;
a variable current carrying path which switches a current carrying path among the driving target device, the DC power source and the reactor to perform an operation in one of plural operation modes including at least a hold mode in which a gate of the driving target device is directly connected to a positive electrode or a negative electrode of the DC power source to hold the driving target device in an ON state or an OFF state, a preparation mode in which the ON state or the OFF state of the driving target device held in the hold mode is held and a closed loop for causing the reactor current to flow through the reactor from a positive electrode side terminal to a negative electrode side terminal is formed between the DC power source and the reactor, and an execution mode in which a closed loop for causing a gate current having a magnitude equal to a reactor current to flow in or to flow out is formed between the reactor and parasitic capacitance of the gate of the driving target device, the variable current carrying path including a backflow path for causing the reactor current flowing through the reactor to flow back to the DC power source when a gate voltage of the driving target device deviates from a preset allowable voltage range; and
a drive control part which sets the operation mode of the variable current carrying path to the hold mode and holds the ON state or the OFF state of the driving target device, and further switches the operation mode in sequence of the preparation mode and the execution mode, and realizes turn-on or turn-off of the driving target device.
2. The gate driving circuit according to claim 1, wherein the DC power source and the driving target device are connected so that a potential of one of the positive electrode and the negative electrode of the DC power source becomes a reference potential to a gate potential of the driving target device.
3. The gate driving circuit according to claim 1, wherein the DC power source and the driving target device are connected so that an intermediate potential between the positive electrode and the negative electrode of the DC power source becomes a reference potential to a gate potential of the driving target device.
4. The gate driving circuit according to claim 1, further comprising:
a load detection unit to detect a magnitude of a load driven by the driving target device,
wherein the drive control part sets a magnitude of the reactor current made to flow in the preparation mode in accordance with a detection result in the load detection unit.
5. The gate driving circuit according to claim 1, further comprising:
a current detection unit to detect the reactor current,
wherein the drive control part continues the execution mode until a magnitude of the reactor current detected by the current detection unit becomes zero.
6. The gate driving circuit according to claim 1, wherein the drive control unit causes a continuation time of the execution mode to have a fixed length.
7. The gate driving circuit according to claim 1, wherein the variable current carrying path includes:
a first switch to interrupt a current carrying path from the positive electrode side terminal as one end of the reactor to the positive electrode of the DC power source;
a second switch to interrupt a current carrying path from the negative electrode side terminal as the other end of the reactor to the negative electrode of the DC power source;
a third switch to interrupt a current carrying path from the positive electrode side terminal of the reactor to the gate of the driving target device;
a fourth switch to interrupt a current carrying path from the negative electrode side terminal of the reactor to the gate of the driving target device;
a first diode whose anode is connected to the negative electrode side terminal of the reactor and whose cathode is connected to the positive electrode of the DC power source; and
a second diode whose cathode is connected to the positive electrode side terminal of the reactor and whose anode is connected to the negative electrode of the DC power source.
8. The gate driving circuit according to claim 7, wherein:
the drive control part turns on the first and the third switches and turns off the second and the fourth switches, in the hold mode to hold the driving target device in the ON state;
the drive control part turns off the first and the third switches and turns on the second and the fourth switches, in the hold mode to hold the driving target device in the OFF state;
the drive control part turns on both the first and the second switches in the preparation mode, while holding the third and the fourth switches in the hold mode; and
the drive control part turns off both the first and the second switches from a state of the preparation mode in the execution mode.
9. The gate driving circuit according to claim 8, wherein the third and the fourth switches are bidirectional switches.
10. The gate driving circuit according to claim 9, wherein the bidirectional switch includes a pair of series-connected transistors having reverse-biased diodes, and the reverse-biased diodes are directed in opposite directions to each other.
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 cycloolefin transparent resin composition comprising:
a metal salt rosinate; and
a noncrystalline polyolefin resin including a cycloolefin component as a copolymer component;
wherein the noncrystalline polyolefin is included as a main component;
wherein the metal salt rosinate is a metal salt of one or more members selected from the group consisting of compounds represented by general formulae (I), (II), (Ill), and (IV);
wherein the metal salt rosinate is present in a content equal to or more than 0.1 parts by mass and equal to or less than 5 parts by mass on a basis of 100 parts by mass of the noncrystalline polyolefin resin;
wherein the metal salt comprises one or more members selected from the group consisting of an alkali metal salt, an alkaline earth metal salt, a Group 12 metal salt, and combinations thereof;
wherein the composition displays prevention of clouding generated by exposure to high temperature and high humidity atmosphere.
2. The cycloolefin transparent resin composition according to claim 1, wherein the alkali metal salt comprises at least one of a sodium salt or a potassium salt.
3. The cycloolefin transparent resin composition according to claim 1, wherein the alkaline earth metal salt comprises at least one of a calcium salt or a magnesium salt.
4. The cycloolefin transparent resin composition according to claim 1, wherein the Group 12 metal salt comprises a zinc salt.
5. The cycloolefin transparent resin composition according to claim 1, wherein the noncrystalline polyolefin resin is a copolymer including:
(A) an \u03b1-olefin component having 2 to 20 carbons; and
(B) a cycloolefin component represented by general formula (V)
wherein R1-R12 may independently be the same or different, and are each selected from the group consisting of hydrogen atom, halogen atom, and hydrocarbon radical,
R9 and Rl0, R11 and R12 may be combined to form a divalent hydrocarbon radical,
R9 and R10, R11 and R12 may form a ring by joining each other;
n represents 0 or a positive integer, and
when n is two, or more, R5-R8 may be the same or different, independently, for each repeating unit.
6. The cycloolefin transparent resin composition according to claim 1, wherein the composition forms a molded article and has a light transmittance measured at a wavelength of 500-750 nm with a 2 mm light path length of 90% or more.
7. The cycloolefin transparent resin composition according to claim 1, wherein the composition forms a molded article and has a light transmittance measured at a wavelength of 400-750 nm with a 2mm light path length of 80% or more.
8. An optical material comprising the cycloolefin transparent resin composition according to claim 1.
9. An optical element obtained by molding the cycloolefin transparent resin composition according to claim 1.
10. An optical element according to claim 9, wherein the optical elements are any one of a lens, a light guide plate, or a diffraction grating.
11. A method comprising:
contacting a resin composition with an antihazing agent to form a noncrystalline resin mixture, the resin composition including: a noncrystalline cycloolefin resin which includes a cyclic olefin component as a copolymer component; the antihazing agent including a metal salt rosinate;
forming the noncrystalline resin mixture into a molded article, wherein transparency of the molded article is maintained;
wherein the metal salt rosinate is a metal salt of one or more members selected from the group consisting of compounds represented by general formulae (I), (II), (Ill), and (IV);
wherein the metal salt rosinate is present in a content equal to or more than 0.1 parts by mass and equal to or less than 5 parts by mass on a basis of 100 parts by mass of the noncrystalline cycloolefin resin;
wherein the metal salt comprises one or more members selected from the group consisting of an alkali metal salt, an alkaline earth metal salt, a Group 12 metal salt, and combinations thereof;
wherein the noncrystalline resin mixture displays prevention of clouding generated by exposure to high temperature and high humidity atmosphere.
12. The method according to claim 11, wherein the alkali metal salt includes at least one of a sodium salt or a potassium salt, the alkaline earth metal salt includes at least one of a calcium salt or a magnesium salt, wherein the Group 12 metal salt includes a zinc salt.
13. The method according to claim 11, wherein the noncrystalline cycloolefin resin is a copolymer including:
(A) an \u03b1-olefin component having 2 to 20 carbons; and
(B) a cycloolefin component represented by general formula (V)
wherein R1-R12 may independently be the same or different, and are each selected from the group consisting of hydrogen atom, halogen atom, and hydrocarbon radical,
R9 and R10, R11 and R12 may be combined to form a divalent hydrocarbon radical,
R9 and R10, R11 and R12 may form a ring by joining each other;
n represents 0 or a positive integer, and
when n is two or more, R5-R8 may be the same or different, independently, for each repeating unit.
14. The method according to claim 11, wherein the molded article is selected from the group consisting of lenses, light guide paths, and diffraction gratings, having a light transmittance measured at a wavelength of 400-750 nm with a 2mm light path length of 80% or more.