System and method for detecting a position of a movable element

• US 7,518,100 B2
• Filed: 05/08/2006
• Issued: 04/14/2009
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• Current Assignee: Phaedrus, LLC
• Original Assignee: Phaedrus, LLC
• Inventors: Engstrand, Bradley
• Primary Examiner(s): Luu; Thanh X
• Application Number:
  US11/430,161
• Publication Number:
  US 20070075228A1
• Time in Patent Office: 1,072 Days
• Field of Search: 250/231.1, 91/1, 92/5.R
• US Class Current: 250/231.1
• CPC Class Codes: G01D 5/28 with deflection of beams of light, e.g. for direct optical indication G01D5/40 takes precedence; mechanical adjustment G01D5/264
• CPC Class Codes: G01D 5/34 the beams of light being detected by photocells

Abstract

A system and a method detect a position of a movable element within the interior of the compartment via a light source and/or a light sensor. The light sensor is connected to a platform and/or to a film for detecting an intensity of a light within the interior of the compartment. The film, a bottom surface of an end cap and/or a surface of the movable element and/or the compartment attenuate light within the interior of the compartment and/or within an interior of the end cap. The intensity of the light detectable by the light sensor corresponds to the position of the movable element within the interior of the compartment. The position of the movable element within the interior of the compartment is detected by the light sensor via the intensity of the light detectable by the light sensor. The film, the platform, the bottom surface of the end cap and/or the surface of the movable element and/or of the compartment minimize diffraction of the light within the interior of the compartment and/or within the interior of the end cap.

Claims

1. A system for detecting a position of a movable element wherein the movable element has a surface, the system comprising:

a compartment having a body defining an interior wherein the body has an interior surface and a length defined between a first end and a second end of the compartment wherein the movable element moves within the interior of the compartment between the first end and the second end of the compartment;

a cap having bottom surface and walls defining an interior of the cap wherein the walls are connected to the bottom surface wherein the cap is connected to the first end of the compartment wherein the interior of the compartment is adjacent to the interior of the cap;

a film connected to the walls of the cap wherein the film encloses the interior of the cap wherein the film diffuses light emitted into the interior of the compartment; and

a sensor connected to the cap wherein the sensor is adjacent to the first end of the compartment wherein the sensor detects an intensity of the light within the interior of the compartment which is attenuated by the interior surface of the compartment or by the surface of the movable element wherein the intensity of the light within the interior of the compartment corresponds to the position of the movable element within the interior of the compartment.

2. The system of claim 1 wherein the film is made from glass or plastic.

3. The system of claim 1 further comprising:

a light source connected to the cap wherein the light source projects the light into the interior of the compartment.

4. The system of claim 1 further comprising:

a platform attached to the walls of the cap wherein the platform connects the sensor to the cap.

5. The system of claim 1 further comprising:

a coating on the interior surface of the compartment wherein the coating attenuates the light emitted into the interior of the compartment.

6. The system of claim 1 further comprising:

a microprocessor connected to the sensor wherein the microprocessor is in communication with the sensor.

7. The system of claim 1 further comprising:

a coating on the surface of the movable element wherein the coating attenuates the light emitted within the interior of the compartment.

8. The system of claim 1 wherein the sensor is attached to the bottom surface of the cap wherein the sensor detects an intensity of light within the interior of the cap.

9. A system for detecting a position of a movable element, the system comprising:

a compartment having a body defining an interior wherein the body has an interior surface and a length defined between a first end and a second end of the compartment;

a cap having a bottom surface and walls defining an interior of the cap wherein the walls are connected to the bottom surface wherein the cap is connected to the first end of the compartment;

a light source connected to the cap wherein the light source transmits light into the interior of the cap and the interior of the compartment wherein the interior surface of the compartment attenuates the light within the interior of the compartment;

a film connected to the walls of the cap wherein the film separates the interior of the cap and the interior of the compartment wherein the film diffuses light transmitted into the interior of the cap and the interior of the compartment; and

a sensor connected to the walls of the cap wherein the sensor detects an intensity of the light within the interior of the cap or the interior of the compartment wherein the intensity of the light corresponds to the light attenuated by the interior surface of the compartment wherein the light attenuated by the interior surface of the compartment corresponds to the position of the movable element.

10. The system of claim 9 wherein the film is made from glass or plastic.

11. The system of claim 9 further comprising:

a platform attached to the walls of the cap wherein the platform is located between the interior of the cap and the film.

12. The system of claim 9 further comprising:

a coating on the movable element wherein the coating attenuates the light within the interior of the compartment.

13. The system of claim 9 wherein the sensor is attached to the film wherein the sensor is located within the interior of the compartment.

14. The system of claim 9 further comprising:

a coating on the interior surface of the compartment wherein the coating attenuates the light within the interior of the compartment.

15. A method for detecting a position of a movable element, the method comprising the steps of:

providing a compartment having a body defining an interior wherein the body has an interior surface and a length defined between a first end and a second end;

positioning a movable element within the interior of the compartment wherein the movable element moves within the interior of the compartment between the first end and the second end of the compartment;

connecting a film to the first end of the compartment wherein the film encloses the interior of the compartment wherein the film diffuses light emitted from the first end of the compartment into the interior of the compartment; and

detecting an intensity of the light within the interior of the compartment wherein the intensity of the light corresponds to an amount of the light attenuated by the interior surface of the compartment and the movable element wherein the amount of light attenuated corresponds to the position of the movable element within the interior of the compartment.

16. The method of claim 15 further comprising the step of:

connecting a cap to the first end of the compartment wherein the cap has an interior which is separated from the interior of the compartment via the film.

17. The method of claim 15 further comprising the step of:

moving the movable element from the first position to a second position with respect to the interior of the compartment.

18. The method of claim 15 further comprising the step of:

connecting a light source to the first end of the compartment wherein the light source emits the light into the interior of the compartment via the film.

19. The method of claim 15 further comprising the step of:

attaching a platform to the first end of the compartment wherein the film is located between the interior of the compartment and the platform.

20. The method of claim 15 further comprising the step of:

forming a surface on the movable element wherein the surface attenuates the light within the interior of the compartment.