1-14. (canceled)
15. A method, comprising determining an amount of a first current from an amount of a charge stored in a first capacitor.
16. The method of claim 15, wherein determining comprises:
charging the first capacitor with the first current; and
measuring the amount of the charge stored in the first capacitor as a result of the charging.
17. The method of claim 16, wherein determining further comprises determining an amount of charging time, and charging comprises charging the first capacitor for the charging time.
18. The method of claim 17, wherein determining further comprises disconnecting the first capacitor from the first current at an expiration of the charging time.
19. The method of claim 16, wherein determining further comprises:
charging a second capacitor with a second current;
comparing a voltage across the second capacitor with a reference voltage; and
disconnecting the first capacitor from the first current responsive to the voltage across the second capacitor reaching the reference voltage,
wherein measuring is performed while the first capacitor is disconnected from the first current.
20. The method of claim 19, wherein determining further comprises fully discharging the second capacitor prior to charging the second capacitor.
21. The method of claim 16, wherein determining further comprises converting the measured amount of the charge stored in the first capacitor into a multi-bit digital value.
22. The method of claim 16, wherein determining further comprises fully discharging the first capacitor.
23. An apparatus for determining an amount of a first current, the apparatus comprising:
a first capacitor;
a first switch;
a control unit configured to control the first switch to selectively connect and disconnect the first capacitor from a first current; and
a measurement unit configured to measure a charge across the first capacitor after the first capacitor is disconnected from the first current and to generate an output signal based on the measured charge.
24. The apparatus of claim 23, wherein the measurement unit comprises an amplifier having a pair of inputs connected across the capaciator.
25. The apparatus of claim 23, further comprising:
a second capacitor; and
a second switch, wherein the control unit is further configured to control the second switch to selectively connect and disconnect the second capacitor from the second current, and to control the first switch to disconnect the first capacitor from the first current depending upon a voltage formed across the second capacitor.
26. The apparatus of claim 25, further comprising a comparator configured to compare the voltage across the second capacitor with a reference voltage, wherein the control unit is further configured to control the first switch responsive to an output of the comparator.
27. The apparatus of claim 26, wherein the control unit is further configured to control the first switch to disconnect the first capacitor from the first current responsive to the output of the comparator indicating that the voltage across the second capacitor has reached the reference voltage.
28. The apparatus of claim 23, further comprising an analog-to-digital converter configured to convert the output signal to a multi-bit digital signal.
29. The apparatus of claim 23, wherein the control unit is further configured to fully discharge the first capacitor.
30. An apparatus, comprising:
a reference timer circuit configured to generate a first signal indicating an expiration of a time period; and
a sense circuit comprising a first capacitor and configured to sense, responsive to the first signal, a charge stored in the first capacitor, and to generate a second signal representing the sensed charge.
31. The apparatus of claim 30, further comprising an amplifier configured to amplifier the second signal.
32. The apparatus of claim 30, wherein the sense circuit comprises:
a second capacitor; and
a comparator having a first input connected to the capacitor and a second input connected to a reference voltage, wherein the comparator is configured to generate the second signal.
33. The apparatus of claim 30, further comprising:
a first switch in series with the first capacitor; and
a second switch connected across the first capacitor.
34. The apparatus of claim 33, further comprising a control circuit configured to control the first and second switches in accordance with the first signal.
35. The apparatus of claim 34, wherein the control circuit is further configured to control the first and second switches so that only one of the first and second switches conducts at any given time.
36. An apparatus for determining an amount of a current, comprising:
means for determining a time period;
means for charging a capacitor with a current for the time period; and
means for sensing a charge across the capacitor at an end of the time period.
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 solid-state imaging device comprising:
a plurality of light-receiving elements each of which photoelectrically converts incident light; and
a plurality of dispersive elements disposed on a light-incident side of the light-receiving elements,
wherein each of the dispersive elements includes:
a first light transmissive film material; and
a second light transmissive film material with a property of having a refractive index that is lower than a refractive index of the first light transmissive film material in a first wavelength range of the incident light and higher than the refractive index of the first light transmissive film material in a second wavelength range of the incident light, the second wavelength range being longer in wavelength than the first wavelength range, and
a volume occupation ratio of the first light transmissive film material in the each of the dispersive elements increases from one end of the each of the dispersive elements towards an other end of the each of the dispersive elements in a direction parallel to a light-receiving surface of the light-receiving elements, while a volume occupation ratio of the second light transmissive film material in the each of the dispersive elements increases from the other end towards the one end in the direction, the other end being opposite the one end.
2. The solid-state imaging device according to claim 1,
wherein the dispersive elements include a first dispersive element and a second dispersive element which are adjacent to each other in the direction, and
the first dispersive element and the second dispersive element are arranged to cause (a) a set of the first light transmissive film material and the second light transmissive film material in the first dispersive element and (b) a set of the first light transmissive film material and the second light transmissive film material in the second dispersive element adjacent to the first dispersive element are symmetric with respect to a boundary between the first dispersive element and the second dispersive element, the boundary being a plane including a normal of the light-receiving surface.
3. The solid-state imaging device according to claim 1,
wherein as a wavelength of the incident light is longer, the refractive index of the first light transmissive film material decreases.
4. The solid-state imaging device according to claim 1,
wherein the first light transmissive film material is stacked on a light-incident side of the second light transmissive film material.
5. The solid-state imaging device according to claim 1,
wherein the second light transmissive film material is stacked on a light-incident side of the first light transmissive film material.
6. The solid-state imaging device according to claim 1,
wherein each of the dispersive elements includes a plurality of divided portions each having a width shorter than a wavelength of the incident light, and
the divided portions include:
a first portion comprising the first light transmissive film material; and
a second portion comprising the second light transmissive film material.
7. The solid-state imaging device according to claim 1,
wherein each of the dispersive elements has a substantially rectangular shape when viewed from a normal direction of the light-receiving surface, and
the solid-state imaging device further comprises a microlens disposed for a corresponding one of the dispersive elements, the microlens having a substantially elliptical shape when viewed from the normal direction,
wherein the microlens has a longest diameter equal to a length of a first side of the corresponding one of the dispersive elements, and a shortest diameter equal to a length of a second side of the corresponding one of the dispersive elements, and
the first side is perpendicular to the second side.
8. The solid-state imaging device according to claim 1,
wherein each of the dispersive elements has a substantially rectangular shape when viewed from a normal direction of the light-receiving surface, and
the solid-state imaging device further comprises a microlens disposed for a corresponding one of the dispersive elements, the microlens having a substantially rectangular shape when viewed from the normal direction.
9. The solid-state imaging device according to claim 1,
wherein the refractive index of the first light transmissive film material is equal to the refractive index of the second light transmissive film material at a wavelength within a range from 490 nm to 580 nm of a wavelength of the incident light.
10. The solid-state imaging device according to claim 1,
wherein the first light transmissive film material comprises indium tin oxide (ITO), and
the second light transmissive film material comprises aluminum oxide (Al2O3).