Photodiode array for an optical encoder, photodiode detection system, and optical encoder
A photodiode detector array for an optical encoder includes a sequence of photodiodes having a pitch between adjacent photodiodes that alternates between a first pitch and a second pitch, the second pitch being different than the first pitch.
1. A photodiode detector array for an optical encoder, comprising:
a sequence of photodiodes having a pitch distance between adjacent photodiodes that alternates between a first pitch distance and a second pitch distance, the second pitch distance being different than the first pitch distance.
2. The photodiode detector array according to claim 1 , wherein the following equation is satisfied:
second pitch distance=first pitch distance*((3+4 i )/(2+4 i )),
representing an integer greater than or equal to 0.
3. The photodiode detector array according to claim 1 , wherein the second pitch distance is 1.5 times the first pitch distance.
4. The photodiode detector array according to claim 1 , wherein the following equation is satisfied:
second pitch distance=first pitch distance*((2+4 i )/(1+4 i )),
representing an integer greater than or equal to 0.
5. The photodiode detector array according to claim 1 , wherein the second pitch distance is 1.2 times the first pitch distance.
6. The photodiode detector array according to claim 1 , wherein the photodiode array has a plurality of channels, each channel including a first complementary photodiode and a second complementary photodiode.
7. The photodiode detector array according to claim 6 , wherein each of the first complementary photodiode and the second complementary diode repeats with a third pitch distance, the third pitch distance one of (a) alternating between 4 times the first pitch distance and 6 times the first pitch distance and (b) alternating between 5⅓ times the first pitch distance and 3⅓ times the first pitch distance.
8. The photodiode detector array according to claim 6 , wherein each of the first complementary photodiode and the second complementary photodiode repeats with a third pitch distance, the third pitch distance alternating between 5.6 times the first pitch distance and 3.2 times the first pitch distance.
9. The photodiode detector array according to claim 1 , wherein the pitch distance between adjacent photodiodes repeatedly alternates between the first pitch distance and the second pitch distance.
10. An optical encoder, comprising:
a light source;
a photodiode detector array including a sequence of photodiodes having a pitch distance between adjacent photodiodes that alternates between a first pitch distance and a second pitch distance, the second pitch distance being greater than the first pitch distance; and
a scale index member configured to direct light from the light source to the photodiodes.
11. The optical encoder according to claim 10 , wherein the scale index member is a code disk.
12. The optical encoder according to claim 10 , wherein the scale index member includes slots having a slot pitch distance, the slot pitch being twice the first pitch distance.
13. The optical encoder according to claim 10 , wherein the scale index member includes slots having a slot pitch distance, the slot pitch distance being ⅘ the first pitch distance.
14. The optical encoder according to claim 10 , wherein the photodiode array has a plurality of channels, each channel including a first complementary photodiode and a second complementary photodiode.
15. The optical encoder according to claim 10 , wherein the pitch distance between adjacent photodiodes repeatedly alternates between the first pitch distance and the second pitch distance.
16. An optical encoder, comprising:
a light source;
a photodiode detector array including a sequence of photodiodes having a pitch between adjacent photodiodes that alternates between a first pitch and a second pitch, the second pitch being greater than the first pitch; and
a scale index member configured to direct light from the light source to the photodiodes;
wherein at least one of the following equations is satisfied:
second pitch=first pitch*((3+4 i )/(2+4 i )); and (a)
second pitch=first pitch*((2+4 i )/(1+4 i )); (b)
i representing an integer greater than or equal to 0.
17. The optical encoder according to claim 10 , wherein the second pitch distance is one of (a) 1.5 times the first pitch distance, (b) alternating between 5⅓ times the first pitch distance and 3⅓ times the first pitch distance, and (c) 1.2 times the first pitch distance.
18. The optical encoder according to claim 16 , wherein the scale index member is a code disk.
19. The optical encoder according to claim 16 , wherein the scale index member includes slots having a slot pitch, the slot pitch being twice the first pitch.
20. The optical encoder according to claim 16 , wherein the scale index member includes slots having a slot pitch, the slot pitch being ⅘ the first pitch.
21. The optical encoder according to claim 16 , wherein the second pitch is one of (a) 1.5 times the first pitch, (b) alternating between 5⅓ times the first pitch and 3⅓ times the first pitch, and (c) 1.2 times the first pitch.
22. The optical encoder according to claim 16 , wherein the photodiode array has a plurality of channels, each channel including a first complementary photodiode and a second complementary photodiode.
23. The optical encoder according to claim 16 , wherein each of the first complementary photodiode and the second complementary diode repeats with a third pitch, the third pitch one of (a) alternating between 4 times the first pitch and 6 times the first pitch and (b) alternating between 5.4 times the first pitch and 3.4 times the first pitch.
24. The optical encoder according to claim 16 , wherein the pitch between adjacent photodiodes repeatedly alternates between the first pitch and the second pitch.
25. An optical encoder, comprising:
a light source;
a photodiode detector array including a sequence of photodiodes having a pitch between adjacent photodiodes that alternates between a first pitch and a second pitch, the second pitch being greater than the first pitch; and
a scale index member configured to direct light from the light source to the photodiodes;
wherein each of the first complementary photodiode and the second complementary diode repeats with a third pitch, the third pitch one of (a) alternating between 4 times the first pitch and 6 times the first pitch and (b) alternating between 5.4 times the first pitch and 3.4 times the first pitch.
26. The optical encoder according to claim 25 , wherein the scale index member is a code disk.
27. The optical encoder according to claim 25 , wherein the scale index member includes slots having a slot pitch, the slot pitch being twice the first pitch.
28. The optical encoder according to claim 25 , wherein the scale index member includes slots having a slot pitch, the slot pitch being ⅘ the first pitch.
29. The optical encoder according to claim 25 , wherein the second pitch is one of (a) 1.5 times the first pitch, (b) alternating between 5⅓ times the first pitch and 3⅓ times the first pitch, and (c) 1.2 times the first pitch.
30. The optical encoder according to claim 25 , wherein the photodiode array has a plurality of channels, each channel including a first complementary photodiode and a second complementary photodiode.
31. The optical encoder according to claim 25 , wherein the pitch between adjacent photodiodes repeatedly alternates between the first pitch and the second pitch.