1. An optical pickup apparatus comprising:
a photodetector including first to fourth light-receiving portions obtained by dividing the photodetector into four portions along a first direction optically corresponding to a direction orthogonal to a tracking direction and a second direction optically corresponding to the tracking direction, the photodetector configured to be irradiated with a laser light applied to a signal recording layer of an optical disc and thereafter reflected by the signal recording layer of the optical disc;
a first generating unit configured to generate a focus error signal by performing subtraction on a first addition signal obtained by adding respective signals from the first and third light-receiving portions, arranged in one diagonal direction, among the first to fourth light-receiving portions, and a second addition signal obtained by adding respective signals from the second and fourth light-receiving portions arranged in another diagonal direction among the first to fourth light-receiving portions;
a second generating unit configured to generate a tracking error signal by performing subtraction on a third addition signal obtained by adding respective signals from the first and fourth light-receiving portions arranged in the first direction, and a fourth addition signal obtained by adding respective signals from the second and third light-receiving portions arranged in the first direction;
first to fourth low-pass filters configured to allow respective signals to be input thereto from the first to fourth light-receiving portions;
a third generating unit configured to generate a first correction signal for correcting the focus error signal by performing subtraction on a fifth addition signal obtained by adding respective signals from the first and fourth low-pass filters, and a sixth addition signal obtained by adding respective signals from the second and third low-pass filters; and
a correction unit configured to correct the focus error signal based on the first correction signal.
2. The optical pickup apparatus of claim 1, wherein the correction unit
includes a first correction unit configured to multiply the first correction signal by a first correction factor for correcting a level of the first correction signal, and wherein
the correction unit is configured to correct the focus error signal based on a correction signal obtained from the first correction unit.
3. The optical pickup apparatus of claim 2, wherein
the correction unit further includes:
a fourth generating unit configured to generate a second correction signal by performing subtraction on the tracking error signal obtained from the second generating unit, and the correction signal obtained from the first correction unit; and
a second correction unit configured to multiply the second correction signal by a second correction factor for correcting a level of the second correction signal, and wherein
the correction unit is configured to correct the focus error signal based on a correction signal obtained from the second correction unit.
4. The optical pickup apparatus of claim 3, wherein
the correction unit further includes a fifth generating unit configured to generate a corrected focus error signal by performing subtraction on the focus error signal obtained from the first generating unit, and the correction signal obtained from the second correction unit.
5. The optical pickup apparatus of claim 4, wherein
the second correction signal includes a corrected tracking error 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 radiopharmaceutical heater comprising:
a heat-transfer member having a receptacle defined therein to receive a container, the heat-transfer member having a thermal conductivity greater than about 100 W(mK);
a radiation shield disposed about the heat-transfer member, wherein the radiation shield comprises lead, tungsten, tungsten-impregnated plastic, depleted uranium, or any combination thereof; and
a heating element in thermal communication with the heat-transfer member, wherein at least a portion of the heating element is located within the radiation shield.
2. The heater of claim 1, wherein an entirety of the heating element is located within the radiation shield.
3. The heater of claim 1, wherein at least a portion of the heating element is located within the heat-transfer member.
4. (canceled)
5. The heater of claim 1, further comprising:
a container having a radiopharmaceutical disposed therein, wherein the container is disposed within the receptacle defined in the heat-transfer member.
6. The heater of claim 5, wherein a clearance between the container and the portion of the heat-transfer member that defines the receptacle is no more than about 0.001 inches (0.0254 mm).
7. The heater of claim 1, wherein at least a portion of the heat-transfer member comprises aluminum.
8. (canceled)
9. The heater of claim 1, wherein the thermal conductivity of the heat-transfer member is greater than about 150 W(mK).
10-23. (canceled)
24. A radiopharmaceutical heater comprising:
a compliant heat-transfer member shaped to receive a container;
a radiation shield disposed near the compliant heat-transfer member; and
a heating element in thermal communication with the compliant heat-transfer member.
25. The heater of claim 24, wherein the compliant heat-transfer member comprises silicone, poly-tetraflouroethane, or a combination thereof.
26-27. (canceled)
28. The heater of claim 24, wherein the radiation shield comprises:
a first radiation-shield member; and
a second radiation-shield member coupled to the first radiation-shield member with two or fewer degrees of freedom of relative movement between the first radiation-shield member and the second radiation-shield member.
29. The heater of claim 28, comprising:
a shaft;
a cam affixed to the shaft;
a lever affixed to the shaft and configured to rotate the cam; and
a guide-member coupled to the first radiation-shield member, wherein the cam is configured to move the first radiation-shield member along a path defined by the guide member, and wherein the path is toward the second radiation-shield member.
30-38. (canceled)
39. The heater of claim 24, further comprising:
a spill tray disposed at least partially under the radiation shielding.
40. The heater of claim 39, wherein the spill tray comprises a slide rail.
41. (canceled)
42. The heater of claim 39, wherein the spill tray comprises an absorbent medium.
43. A radiopharmaceutical heater comprising:
a heater block having a container receptacle;
a container in the container receptacle, wherein the container has a radiopharmaceutical therein;
a member biasing the container against the heater block either directly or indirectly; and
radiation shielding disposed near the container.
44. The heater of claim 43, wherein the member biasing the container comprises a spring.
45. The heater of claim 43, wherein the heater comprises a lid, and wherein the member is biased against the container by the lid.
46. (canceled)
47. The heater of claim 43, comprising a compliant heat-transfer member disposed between the container and the heater block.
48. The heater of claim 43, comprising a button, wherein the member is biased against the container by the button.
49. The heater of claim 43, comprising a plurality of containers, wherein the heater block comprises a plurality of receptacles, and wherein a container is disposed in at least one of the receptacles.
50-55. (canceled)