1. A laser diode module multi-layer board comprising:
a light emittingreceiving unit mounting area for mounting thereon a light emittingreceiving unit component including a semiconductor laser diode for generating light irradiated to a storage medium, and a light receiving element for receiving reflected light from the storage medium; and
a laser diode protection component mounting area for mounting thereon a laser diode protection component for protecting said semiconductor laser diode from electric damages.
2. A laser diode module multi-layer board according to claim 1, wherein:
said board contains at least some of circuit elements of a high-frequency superposing circuit for superposing a high-frequency current on a current for driving said semiconductor laser diode, and at least some of circuit elements of an anti-EMC circuit for reducing electromagnetic noise produced from said high-frequency superposing circuit.
3. A laser diode module multi-layer board according to claim 2, further comprising a coil mounting area for mounting thereon a coil which forms part of said anti-EMC circuit, wherein:
said anti-EMC circuit comprises a capacitor incorporated in said board, and
said capacitor is arranged at a position substantially beneath said coil mounting area.
4. A laser diode module multi-layer board according to claim 1, further comprising a heat dissipating via hole extending through said laser diode module multi-layer board and formed in an area in which said light emittingreceiving unit component is mounted, for dissipating heat produced from said semiconductor laser diode to the opposite surface side of said board to the board surface on which said light emittingreceiving unit mounting area is defined.
5. A laser diode module multi-layer board according to claim 1, further comprising a connection pattern for a flexible printed circuit board, wherein:
said light emittingreceiving unit mounting area is defined on one surface of said laser diode module multi-layer board, and
said connection pattern for a flexible printed circuit board is defined on the other surface of said laser diode module multi-layer board.
6. A laser diode module multi-layer board according to claim 5, wherein said connection pattern for a flexible printed circuit board is formed in arrangement along an edge of said laser diode module multi-layer board.
7. A laser diode module multi-layer board according to claim 6, further comprising a heat dissipating via hole extending through said laser diode module multi-layer board and formed in an area in which said light emittingreceiving unit component is mounted, for dissipating heat produced from said semiconductor laser diode to the opposite surface side of said board to the board surface on which said light emittingreceiving unit mounting area is defined,
wherein said connection pattern for a flexible printed circuit board is disposed on each of both sides of the area in which said heat dissipation via hole is formed.
8. A laser diode module multi-layer board according to claim 1, further comprising an active element mounting area for mounting thereon a semiconductor active element which forms part of a high-frequency superposing circuit for superposing a high-frequency current on a current for driving said semiconductor laser diode, wherein:
said light emittingreceiving unit mounting area is defined on one surface of said laser diode module multi-layer board, and
said active element mounting area is defined on the other surface of said laser diode module multi-layer board.
9. A laser diode module multi-layer board according to claim 8, further comprising a reference potential layer disposed between said light emittingreceiving unit mounting area and said active element mounting area.
10. A laser diode module multi-layer board according to claim 9, wherein said board comprises two or more of said reference potential layers.
11. A laser diode module comprising:
a light emittingreceiving unit component including a semiconductor laser diode for generating light irradiated to a storage medium, and a light receiving element for receiving light reflected from the storage medium; and
a laser diode protection component for protecting said semiconductor laser diode from electric damages,
said light emittingreceiving unit component and said laser diode protection component being integrated in a single module.
12. A laser diode module according to claim 11, wherein:
said semiconductor laser diode is a single-mode semiconductor laser diode, and
said module further comprises a high-frequency superposing circuit integrated therein for superposing a high-frequency current on a current for driving said single-mode semiconductor laser diode.
13. A laser diode module according to claim 12, further comprising an anti-EMC circuit integrated therein for reducing electromagnetic noise produced from said high-frequency superposing circuit.
14. A laser diode module according to claim 13, wherein:
said light emittingreceiving unit component is mounted on a surface of a multi-layer board, and
at least one of circuit elements making up one or both of said high frequency superposing circuit and said anti-EMC circuit are incorporated in said multi-layer board.
15. A laser diode module according to claim 13, wherein:
said light emittingreceiving unit component is mounted on a surface of a multi-layer board,
said anti-EMC circuit includes a coil and a capacitor,
said coil is mounted on the surface of said multi-layer board, and
said capacitor is incorporated in said multi-layer board and arranged at a position substantially beneath said coil.
16. A laser diode module according to claim 14, wherein:
said laser diode module multi-layer board includes a heat dissipating via hole extending therethrough and formed in an area in which said light emittingreceiving unit component is mounted, for dissipating heat produced from said semiconductor laser diode to the opposite surface side of said board to the board surface on which said light emittingreceiving unit component is mounted.
17. A laser diode module according to claim 14, further comprising a connection pattern for a flexible printed circuit board, wherein:
said light emittingreceiving unit component is mounted on one surface of said multi-layer board, and
said connection pattern for a flexible printed circuit board is disposed on the other surface of said multi-layer board.
18. A laser diode module according to claim 17, wherein:
said connection pattern for a flexible printed circuit board is formed in arrangement along an edge of said multi-layer board.
19. A laser diode module according to claim 18, wherein:
said laser diode module multi-layer board includes a heat dissipating via hole extending therethrough and formed in an area in which said light emittingreceiving unit component is mounted, for dissipating heat produced from said semiconductor laser diode to the opposite surface side of said board to the board surface on which said light emittingreceiving unit component is mounted, and
said connection pattern for a flexible printed circuit board is arranged on each of both sides of the area in which said heat dissipation via hole is formed.
20. A laser diode module according to claim 14, wherein:
said semiconductor laser diode is a single-mode semiconductor laser diode,
said module further comprises a high-frequency superposing circuit integrated therein for superposing a high-frequency current on a current for driving said single-mode semiconductor laser diode,
said light emittingreceiving unit component is mounted on one surface of said multi-layer board, and
a semiconductor active element included in said high-frequency superposing circuit is mounted on the other surface of said multi-layer board.
21. A laser diode module according to claim 20, further comprising a reference potential layer disposed between said light emittingreceiving unit component and said semiconductor active element.
22. A laser diode module according to claim 21, wherein:
said module comprises two or more of said reference potential layers.
23. A laser diode module according to claim 11, further comprising an IC, integrated therein, capable of controlling a reproduced signal outputted from said light emittingreceiving unit component, or a reproduced signal and a recording signal outputtedinputted tofrom said light emittingreceiving unit component.
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. An computed tomography method using a radiation detector (204) and a radiation source (202), both mounted on a support, the support rotatable around a rotational axis (214); the method comprising:
a) laterally displacing the radiation detector (204) from a position with centered detector geometry with a centered transverse field of view to a first offset position (212);
b) emitting first radiation by the radiation source (202), detecting the first radiation by the radiation detector (204) and acquiring projection data indicative of the first radiation;
c) rotating the support around the rotational axis (214) by 180\xb0;
d) emitting second radiation by the radiation source (202), detecting the second radiation by the radiation detector (204) and acquiring projection data indicative of the second radiation;
e) laterally displacing the radiation detector (204) from the first offset position to a second offset position (226), with opposite direction and double length of the first displacement (a);
f) emitting third radiation by the radiation source (202), detecting the third radiation by the radiation detector (204) and acquiring projection data indicative of the third radiation;
g) rotating the support around the rotational axis (214) by 180\xb0;
h) emitting fourth radiation by the radiation source (202), detecting the fourth radiation by the radiation detector (204) and acquiring projection data indicative of the fourth radiation.
2. The method of claim 1, wherein the detector (204) is a flat panel detector.
3. The method of claim 1, wherein the displacement takes place in a direction parallel to the detector plane.
4. The method according to claim 1, wherein the detector (204) includes a transition region (224) in which the detector generate redundant projection data.
5. The method according to claim 1, wherein the radiation source (202) is shifted according to the displacement of the radiation detector (204).
6. The method according to one of the claims 1 to 5, wherein the rotational axis (214) is the center of the transverse field of view (218).
7. The method according to claim 1, wherein the source (202) emits a radiation beam having a generally fan shaped transverse cross section, the cross section includes first and second outermost rays (242, 244), and the outermost rays intersect the detector (204) at different angles of incidence
8. The method according to claim 1, wherein a focal spot path from the source (202) to the detector (204) keeps a non-zero distance to the rotational axis (214) during first, second, third, and forth emitting and detecting of radiation.
9. The method according to claim 1, wherein the displacement distance from the position with centered detector geometry to the first position and to the second position is less than one half of the detector width (220) in the direction of the displacement (228).
10. The method according to claim 1, comprising the step
using opposing views to reconstruct a 3D imaging data volume.
11. An imaging system for acquiring projection images of a physical object, the system comprising:
a radiation source (202) that generates X-rays;
a radiation detector (204) for detecting rays of radiation originating from the radiation source;
a support that rotatably supports the source and the detector around a rotational axis (214);
wherein the radiation detector (204) is configured to be laterally displaced from a position with centered detector geometry with a centered transverse field of view (FOV) to a first offset position (212) and from the first offset position to a second offset position (226), with opposite direction and double length of the first displacement (a).
12. The imaging system of claim 11, wherein the source is configured to be adjusted from a centered source position according to the detector displacement.
13. A control device configured to actuating means for laterally displacing a radiation detector (204) from a position with centered detector geometry with a centered transverse field of view (FOV) to a first offset position (212) and from the first offset position to a second offset position (226), with opposite direction and double length of the first displacement (a).
14. A computer readable medium having stored thereon computer-executable instructions enabling a computer to carry out a method using a radiation detector (204) and a radiation source (202), both mounted on a support, the support rotatable around a rotational axis (214); the method comprising steps in the following order:
a) laterally displacing the radiation detector (204) from a position with centered detector geometry with a centered transverse field of view to a first offset position (212);
b) emitting first radiation by the radiation source (202), detecting the first radiation by the radiation detector (204) and acquiring projection data indicative of the first radiation;
c) rotating the support around the rotational axis (214) by 180\xb0;
d) emitting second radiation by the radiation source (202), detecting the second radiation by the radiation detector (204) and acquiring projection data indicative of the second radiation;
e) laterally displacing the radiation detector (204) from the first offset position to a second offset position (226), with opposite direction and double length of the first displacement (a);
f) emitting third radiation by the radiation source (202), detecting the third radiation by the radiation detector (204) and acquiring projection data indicative of the third radiation;
g) rotating the support around the rotational axis (214) by 180\xb0;
h) emitting fourth radiation by the radiation source (202), detecting the fourth radiation by the radiation detector (204) and acquiring projection data indicative of the fourth radiation.
15. A computer program element configured and arranged to control when executed on a computer a method using a radiation detector (204) and a radiation source (202), both mounted on a support, the support rotatable around a rotational axis (214); the method comprising steps in the following order:
a) displacing the radiation detector (204) from a position with centered detector geometry with a centered transverse field of view to a first offset position (212);
b) emitting first radiation by the radiation source (202), detecting the first radiation by the radiation detector (204) and acquiring projection data indicative of the first radiation;
c) rotating the support around the rotational axis (214) by 180\xb0;
d) emitting second radiation by the radiation source (202), detecting the second radiation by the radiation detector (204) and acquiring projection data indicative of the second radiation;
e) displacing the radiation detector (204) from the first offset position to a second offset position (226), with opposite direction and double length of the first displacement (a);
f) emitting third radiation by the radiation source (202), detecting the third radiation by the radiation detector (204) and acquiring projection data indicative of the third radiation;
g) rotating the support around the rotational axis (214) by 180\xb0;
h) emitting fourth radiation by the radiation source (202), detecting the fourth radiation by the radiation detector (204) and acquiring projection data indicative of the fourth radiation.