What is claimed is:
1. An optical disc drive capable of recordingreproducing data tofrom an optical disc, said optical disc being either one of a first disc and a second disc, a protective layer of said first disc being thinner that that of said second disc, comprising:
a first laser diode that emits a first laser beam having a first wavelength;
a second laser diode that emits a second laser beam having a second wavelength, said second wavelength being longer than said first wavelength;
an objective lens that converges the first laser beam on said first disc, and the second laser beam on said second disc; and
a driving unit that holds and rotates said optical disc,
an optical axis of said objective lens being inclined relative to a normal to said optical disc,
a beam emitting point of said first laser diode being located at a first position, coma, which is caused when the first laser beam is converged on a data recording surface of said first disc, being minimized when said first laser beam is emitted from said first position, and
a beam emitting point of said second laser diode being located at a second position which is different from said first position, wherein coma, which is caused when the second laser beam is converged on a data recording surface of said second disc, is minimized when said second laser beam is emitted from said second position.
2. The optical disc drive according to claim 1, wherein said objective lens is configured such that coma is minimized for a hypothetical disc under a hypothetical condition, the hypothetical disc being an optical disc having a protective layer whose thickness is intermediate between that of said first disc and that of said second disc, said hypothetical condition being a condition where the optical axis of said objective lens coincides with the normal to said optical disc.
3. The optical disc drive according to claim 2,
wherein a first region is defined on said objective lens, said first region providing a numerical aperture appropriate for converging said second laser beam on said second disc,
wherein said objective lens is configured to satisfy the following condition under a hypothetical condition where the optical axis of said objective lens coincides with the normal to said optical disc:
4.0<SC1SC2<0.25,
wherein, SC1 represents an offense SC against sine condition at the peripheral portion of said first region when the said first laser beam is converged on said first disc,
wherein SC2 represents an offense SC against sine condition at the peripheral portion of said first region when said second laser beam is converged on the second disc,
the offense SC against the sine condition being defined by the formula below:
SCnH1(n sinU)f(1m)
wherein, n represents a refractive index of the beam incident side medium,
n represents a refractive index of the beam emerging side medium,
U represents an angle of the emerging beam with respect to the optical axis,
m represents a paraxial magnification,
H1 represents a ray height on a principal plane, and
f represents a focal length.
4. The optical disc drive according to claim 1,
said optical axis of said objective lens and said normal to said optical disc being included in a reference plane,
said first position and said second position being located on opposite sides with respect to a reference axis,
wherein said reference axis is an optical axis of said objective lens under a hypothetical condition where said optical axis of said objective lens and said normal to said optical disc coincide with each other, and
wherein said reference plane is a plane including said reference axis and said first and second positions.
5. The optical disc drive according to claim 4, wherein said first position and said second position are arranged such that, by arranging the optical axis of said objective lens to be inclined with respect to the normal to said optical disc, said first laser beam is converged on a side where a distance between said objective lens and said optical disc increases, and said second laser beam is converged on a side where a distance between said objective lens and said optical disc decreases.
6. The optical disc drive according to claim 5, wherein said objective lens is configured such that coma is minimized for a hypothetical disc under a hypothetical condition, the hypothetical disc being an optical disc having a protective layer whose thickness is intermediate between that of said first disc and that of said second disc, said hypothetical condition being a condition where the optical axis of said objective lens coincides with the normal to said optical disc.
7. The optical disc drive according to claim 6,
wherein a first region is defined on said objective lens, said first region providing a numerical aperture appropriate for converging said second laser beam on said second disc,
wherein said objective lens satisfies the following condition under the hypothetical condition where the optical axis of said objective lens coincides with the normal to said optical disc:
4.0<SC1SC2<0.25,
wherein, SC1 represents an offense SC against sine condition at the peripheral portion of said first region when the said first laser beam is converged on said first disc,
wherein SC2 represents an offense SC against sine condition at the peripheral portion of said first region when said second laser beam is converged on the second disc,
the offense SC against the sine condition being defined by the formula below:
SCnH1(n sinU)f(1m)
wherein, n represents a refractive index on the beam incident side medium,
n represents a refractive index on the beam emerging side medium,
U represents an angle of the emerging beam with respect to the optical axis,
m represents a paraxial magnification,
H1 represents a ray height on a principal plane, and
f represents a focal length.
8. The optical disc drive according to claim 5, further comprising a fine movement mechanism for driving said objective lens to move for focusing and tracking, said reference axis being inclined with respect to the normal to said optical disc, said objective lens being held by said fine movement mechanism such that said optical axis coincides with said reference axis.
9. The optical disc drive according to claim 8, wherein said driving unit holds said optical disc such that the data recording surface of said optical disc extends in parallel with a bottom surface of a case of said optical disc drive.
10. The optical disc drive according to claim 9, further comprising a mirror member that reflects the laser beam emitted by each of said first laser diode and said second laser diode to impinge on said objective lens, said mirror member bends said reference axis parallel to the data recording surface of said optical disc in the optical disc side.
11. The optical disc drive according to claim 10, further comprising a rough movement mechanism that drives said objective lens in a direction parallel to the data recording surface of said optical disc for seek.
12. The optical disc drive according to claim 8, wherein said driving unit holds said optical disc by inclining the data recording surface with respect to a bottom surface of a case of said optical disc drive so that said reference axis is perpendicular to a bottom surface of a case of said optical disc drive.
13. The optical disc drive according to claim 12, further comprising a mirror member that reflects the laser beam emitted by each of said first laser diode and said second laser diode to impinge on said objective lens, said mirror member bends said reference axis parallel to the data recording surface of said optical disc in the optical disc side.
14. The optical disc drive according to claim 13, further comprising a rough movement mechanism that drives said objective lens in a direction parallel to the data recording surface of said optical disc for seek.
15. The optical disc drive according to claim 5, further comprising a fine movement mechanism for driving said objective lens to move for focusing and tracking, said reference axis coinciding with the normal to said optical disc, said objective lens being held by said fine movement mechanism such that said optical axis is inclined with respect to said reference axis.
16. The optical disc drive according to claim 15, further comprising a mirror member that reflects the laser beam emitted by each of said first laser diode and said second laser diode to impinge on said objective lens, said mirror member bends said reference axis parallel to the data recording surface of said optical disc in the optical disc side.
17. The optical disc drive according to claim 16, further comprising a rough movement mechanism that drives said objective lens in a direction parallel to the data recording surface of said optical disc for seek.
18. The optical disc drive according to claim 15, wherein said driving unit holds said optical disc such that the data recording surface of said optical disc extends in parallel with a bottom surface of a case of said optical disc drive.
19. The optical disc drive according to claim 18, further comprising a mirror member that reflects the laser beam emitted by each of said first laser diode and said second laser diode to impinge on said objective lens, said mirror member bends said reference axis parallel to the data recording surface of said optical disc in the optical disc side.
20. The optical disc drive according to claim 15, further comprising a rough movement mechanism that drives said objective lens in a direction parallel to the data recording surface of said optical disc for seek.
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 treating ammonium containing water in a wastewater treatment site, the method comprising:
receiving a plurality of sensor signals, the plurality of sensor signals comprising at least one of a pH level, an alkalinity level, a specific conductivity level, and an ammonium concentration level; and
controlling flow of a gas into the wastewater treatment site to meet at least one of a target specific conductivity level, a target ammonium concentration level, a target alkalinity level, and a target pH level based on one or more of the plurality of sensor signals.
2. The method of claim 1, wherein the controlling flow of a gas to meet the at least one of the target specific conductivity level, target ammonium concentration level, target alkalinity level, and target pH level is in a continuous flow moving bed biofilm reactor in which partial nitritation and anaerobic ammonium oxidation both occur on a biofilm carrier.
3. The method of claim 1, wherein controlling flow of a gas to meet the at least one of the target specific conductivity level, target ammonium concentration level, target alkalinity level, and target pH level is in a continuous flow integrated fixed film activated sludge reactor in which partial nitritation occurs in a bulk suspended biomass fraction and anaerobic ammonium oxidation occurs on a biofilm carrier.
4. The method of claim 1, further comprising measuring at least one of the specific conductivity level, ammonium concentration level, alkalinity level, and pH level in a reactor.
5. The method of claim 1, further comprising measuring at least one of the specific conductivity level, ammonium concentration level, alkalinity level, and pH level in the effluent from a reactor.
6. The method of claim 1, wherein the gas comprises air or purified oxygen or a blend thereof.
7. The method of claim 1, further comprising controlling a gas valve position based on the at least one of the specific conductivity level, ammonium concentration level, alkalinity level, and pH level.
8. The method of claim 1, further comprising controlling a blower output based on the at least one of the specific conductivity level, ammonium concentration level, alkalinity level, and pH level.
9. The method of claim 1, further comprising controlling a gas flow rate setpoint based on the at least one of the specific conductivity level, ammonium concentration level, alkalinity level, and pH level.
10. The method of claim 9, further comprising controlling a valve position or a blower output based on a gas flow rate setpoint.
11. The method of claim 1, further comprising controlling a dissolved oxygen setpoint based on the at least one of the specific conductivity level, ammonium concentration level, alkalinity level, and pH level.
12. The method of claim 11, further comprising controlling a gas flow rate setpoint based on the dissolved oxygen setpoint.
13. The method of claim 1, further comprising decreasing the flow of gas andor a dissolved oxygen level when the specific conductivity level is lower than a specific conductivity setpoint.
14. The method of claim 1, further comprising increasing the flow of gas andor a dissolved oxygen level when the specific conductivity level is higher than a specific conductivity setpoint.
15. The method of claim 1, further comprising decreasing the flow of gas andor a dissolved oxygen level when the ammonium concentration level is lower than an ammonium concentration setpoint.
16. The method of claim 1, further comprising increasing the flow of gas andor a dissolved oxygen level when the ammonium concentration level is higher than an ammonium concentration setpoint.
17. The method of claim 1, further comprising decreasing the flow of gas andor a dissolved oxygen level when the pH level is lower than a pH setpoint.
18. The method of claim 1, further comprising increasing the flow of gas andor a dissolved oxygen level when the pH level is higher than a pH setpoint.
19. The method of claim 1, further comprising decreasing the flow of gas andor a dissolved oxygen level when the alkalinity level is lower than an alkalinity setpoint.
20. The method of claim 1, further comprising increasing the flow of gas andor a dissolved oxygen level when the alkalinity level is higher than an alkalinity setpoint.
21. The method claim 1, the controlling of flow of the gas comprising an appropriately tuned proportional, a proportional-integral, a proportional-integral-derivative, or a logic-based process.
22. The method of claim 1, further comprising measuring nitrate and ammonia in an influent and in an effluent to determine a nitrate production ratio level.
23. The method of claim 22, wherein the specific conductivity level is controlled according to a nitrate production ratio setpoint such that when the nitrate production ratio level is higher than the nitrate production ratio setpoint the specific conductivity setpoint is increased.
24. The method of claim 22, wherein the ammonium concentration level is controlled according to a nitrate production ratio setpoint such that when the nitrate production ratio level is higher than the nitrate production ratio setpoint the ammonium concentration setpoint is increased.
25. The method of claim 22, wherein the pH is controlled according to the nitrate production ratio setpoint such that when the nitrate production ratio level is higher than the nitrate production ratio setpoint the pH setpoint is increased.
26. The method of claim 22, wherein the alkalinity is controlled according to the nitrate production ratio setpoint such that when the nitrate production ratio is higher than the nitrate production ratio setpoint the alkalinity setpoint is increased.