Separate type photoelectric switch

• US 6,646,251 B1
• Filed: 07/17/2000
• Issued: 11/11/2003
• Est. Priority Date: 03/22/2000
• Status: Expired due to Fees

• Current Assignee: Keyence Corporation (Keyence)
• Original Assignee: Keyence Corporation (Keyence)
• Inventors: Okamoto, Yasuhiro
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): ABDULSELAM, ABBAS I
• Application Number:
  US09/617,861
• Time in Patent Office: 1,212 Days
• Field of Search: 345/46, 345/52, 345/51, 345/156, 250/221, 250/239, 250/22.1, 340/691.6, 235/462.24, 235/462.25, 235/462.2
• US Class Current: 250/221
• CPC Class Codes: G01V 8/12 using one transmitter and one receiver

Abstract

A tolerance-level display portion 12 is provided in a casing 11 of a head 1 of a photoelectric switch. A light reception signal output from the head 1 is transmitted through a cable 31b of a main body 2. The casing 21 of the main body 2 contains a received light amount display portion 22, a tolerance-level display portion 24, adjust switches 28 and setting switches 29. The CPU in the main body 2 calculates a ratio of a light reception signal to a threshold value to obtain a tolerance level, and applies a control signal corresponding to the obtained tolerance level to a variable power supply circuit. The variable power supply circuit applies a variable voltage, which is dependent on the control signal, through a cable 31a to the head 1. The tolerance-level display portion 12 of the head 1 displays a tolerance level on the basis of the variable voltage by turning on the tolerance-level display LEDs 12a, 12b and 12c.

Claims

1. A separate type photoelectric switch which detects an object in a detection area, said separate type photoelectric switch comprising:

a head having a light receiver which receives a light from said detection area and outputs a light reception signal based on the received light; and

a main body located separately from said head and having a processor which detects the object in said detection area on the basis of the light reception signal,

wherein said head includes an indicator which displays information regarding the detection of the object executed by said processor.

2. The separate type photoelectric switch according to claim 1, wherein said processor comprises:

a generator for producing a process signal based on the light reception signal;

a setting unit for setting a reference value ; and

a detecting unit for detecting the object in said detection area by comparing the process signal with the reference value.

3. The separate type photoelectric switch according to claim 2, wherein said processor further comprises a calculator which calculates a relative value of the process signal to the reference value, and said indicator displays a tolerance level based on the relative value.

4. The separate type photoelectric switch according to claim 3, wherein said main body further comprises a display unit for displaying at least one of the process signal, the reference value, and the tolerance level.

5. The separate type photoelectric switch according to claim 3, wherein said main body further comprises a power supply circuit which supplies said head with a power voltage for driving said head, the power voltage being a voltage representative of the relative value calculated by said calculator, and said indicator displays the tolerance level on the basis of the voltage supplied from said main body.

6. The separate type photoelectric switch according to claim 4, wherein said main body further comprises a first display for displaying the reference value comprising a plurality of digit numbers, and an adjustable switch for adjusting the reference value displayed on said first display.

7. The separate type photoelectric switch according to claim 6, wherein said main body further comprises a second display for displaying the relative value calculated by said calculator as a ratio of the process signal to the reference value.

8. The separate type photoelectric switch according to claim 6, wherein said main body further comprises a third display for displaying the process signal comprising a plurality of digit numbers.

9. The separate type photoelectric switch according to claim 6, wherein said processing means further comprises a second display for displaying the relative value calculated by said calculating means as a ratio of the process signal to the reference value.

10. The separate type photoelectric switch according to claim 6, wherein said processing means further comprises a third display for displaying the process signal comprising a plurality of digit numbers.

11. The separate type photoelectric switch according to claim 1, wherein said main body further comprises a power supply circuit which supplies said head with a power voltage for driving said head, the power voltage being a voltage representative of the information regarding the detection of the presence of the object, and said indicator displays the information on the basis of the voltage supplied from said main body.

12. The separate type photoelectric switch according to claim 1, wherein said head further comprises a light projector projecting a light to said detection area.

13. The separate type photoelectric switch according to claim 1, wherein said indicator displays the information in terms of a numerical value.

14. The separate type photoelectric switch according to claim 5, further comprising:

a signal line through which said main body receives the light reception signal output from said light receiver of said head; and

a power line through which said power supply circuit provides the power voltage to said head.

15. A separate type photoelectric switch which detects an object in a detection area, said separate type photoelectric switch comprising:

a head having a light projector which projects a light to said detection area, and a light receiver which receives the light from said detection area and outputs a light reception signal based on the received light;

a main body being formed separately from said head and having a processor which detects the object in said detection area on the basis of the light reception signal; and

a power supply circuit for supplying said head with a power voltage for driving said head, the power voltage being a voltage representative of information on an operation of said head,

wherein said head includes an operating portion for performing a predetermined operation in accordance with the information represented by the voltage supplied from said main body.

16. The separate type photoelectric switch according to claim 15, wherein the information on the operation of said head includes information regarding the detection of the presence of said object executed by said processor, and said operating portion includes an indicator displaying the information on the basis of the voltage supplied from said main body.

17. The separate type photoelectric switch according to claim 16, wherein said indicator displays the information in terms of a numerical value.

18. The separate type photoelectric switch according to claim 15, wherein the information on the operation of said head includes information on the gain of said light receiver, and said operating portion includes a gain select unit for changing the gain of said light receiver on the basis of the voltage supplied from said main body.

19. The separate type photoelectric switch according to claim 15, wherein the information on the operation of said head includes information on the amount of light emitted by said light projector, and said operating portion includes a light-emitting amount select unit for changing the light emitting amount emitted by said light projector on the basis of the voltage supplied from said main body.

20. The separate type photoelectric switch according to claim 15, further comprising:

a signal line through which said main body receives the light reception signal output from said light receiver of said head; and

a power line through which said power supply circuit provides the power voltage to said head.

21. A separate type photoelectric switch which detects an object in a detection area, said separate type photoelectric switch comprising:

light receiving means for receiving light from said detection area and outputting a light reception signal based on the received light; and

processing means separate from said light receiving means for detecting the object in said detection area on the basis of the light reception signal,

wherein said light receiving means includes an indicating means for displaying information regarding the detection of the object executed by said processing means.

22. The separate type photoelectric switch according to claim 21, wherein said processing means comprises:

a generator means for producing a process signal based on the light reception signal;

a setting means for setting a reference value; and

a detecting means for detecting an object in said detection area by comparing the process signal with the reference value.

23. The separate type photoelectric switch according to claim 22, wherein said processing means further comprises a calculating means for calculating a relative value of the process signal to the reference value, and said indicating means displays a tolerance level based on the relative value.

24. The separate type photoelectric switch according to claim 23, wherein said processing means further comprises a display means for displaying at least one of the process signal, the reference value, and the tolerance level.

25. The separate type photoelectric switch according to claim 23, wherein said processing means further comprises a power supply means for supplying said light receiving means with a power voltage for driving said light receiving means, the power voltage being a voltage representative of the relative value calculated by said calculating means, and said indicating means displays the tolerance level on the basis of the voltage supplied from said processing means.

26. The separate type photoelectric switch according to claim 24, wherein said processing means further comprises a first display for displaying the reference value comprising a plurality of digit numbers, and adjustable switching means for adjusting the reference value displayed on said first display.

27. The separate type photoelectric switch according to claim 21, wherein said processing means further comprises a power supply means which supplies said light receiving means with a power voltage for driving said light receiving means, the power voltage being a voltage representative of the information regarding the detection of the presence of the object, and said indicating means displays the information on the basis of the voltage supplied from said processing means.

28. The separate type photoelectric switch according to claim 21, wherein said light receiving means further comprises a light projecting means for projecting a light to said detection area.

29. The separate type photoelectric switch according to claim 21, wherein said indicating means displays the information in terms of a numerical value.

30. The separate type photoelectric switch according to claim 25, further comprising:

a signal line through which said processing means receives the light reception signal output from said light receiving means; and

a power line through which said power supply means provides the power voltage to said light receiving means.

31. A separate type photoelectric switch which detects an object in a detection area, said separate type photoelectric switch comprising:

a head having a light projecting means for projecting a light to said detection area, and a light receiving means for receiving the light from said detection area and outputting a light reception signal based on the received light;

a main body being formed separately from said head and having a processing means which detects the object in said detection area on the basis of the light reception signal; and

a power supply means for supplying said head with a power voltage for driving said head, the power voltage being a voltage representative of information on an operation of said head; and

wherein said head includes an operating means for performing a predetermined operation in accordance with the information represented by the voltage supplied from said main body.

32. The separate type photoelectric switch according to claim 31, wherein the information on the operation of said head includes information regarding the detection of the presence of said object executed by said processing means, and said operating means includes an indicating means for displaying the information on the basis of the voltage supplied from said main body.

33. The separate type photoelectric switch according to claim 32, wherein said indicating means displays the information in terms of a numerical value.

34. The separate type photoelectric switch according to claim 31, wherein the information on the operation of said head includes information on the gain of said light receiving means, and said operating means includes a gain select unit for changing the gain of said light receiving means on the basis of the voltage supplied from said main body.

35. The separate type photoelectric switch according to claim 31, wherein the information on the operation of said head includes information on the amount of light emitted by said light projecting means, and said operating means includes a light emitting amount select unit for changing the light emitting amount emitted by said light projecting means on the basis of the voltage supplied from said main body.

36. The separate type photoelectric switch according to claim 31, further comprising:

a signal line through which said main body receives the light reception signal output from said light receiving means of said head; and

a power line through which said power supply means provides the power voltage to said head.

37. A separate type photoelectric switch which detects an object in a detection area, said separate type photoelectric switch comprising:

a head having a light receiver which receives a light from said detection area and outputs a light reception signal based on the received light; and

a main body located separately from said head and having a processor which detects the object in said detection area on the basis of the light reception signal,

wherein said head includes an indicator which displays information regarding the detection of the object executed by said processor and wherein said head is in signal communication with said main body.

38. The separate type photoelectric switch of claim 37, wherein said head is in signal communication with said main body through a cable.

39. The separate type photoelectric switch of claim 38, wherein said cable is a fiber optic cable.