Auto-focus system using bubble technology

• US 20060092311A1
• Filed: 11/03/2004
• Published: 05/04/2006
• Est. Priority Date: 11/03/2004
• Status: Active Grant

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Inventors: Hartlove, Jason T., Ma, Guolin
• Granted Patent: US 7,557,854 B2
• Time in Patent Office: Days
• US Class Current: 348/340
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: G02B 7/102 controlled by a microcomputer cameras with interchangeable lenses G03B17/14
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

A system and method for auto-focusing light. The system includes at least one focusing lens operable to direct light toward a focal point. The system further includes a sensor array disposed adjacent to the lens assembly such that the light through the lens assembly is directed to the sensor array near the focal point and a bubble array having a plurality of bubble generators. The bubble array supports the sensor array and the bubble generators are operable to maneuver the supported sensor array with respect to the focal point. Such a light focusing system is able to provide an auto-focus capability to a camera system that does not have a large amount of space available for a motor-driven auto-focus system. Furthermore, the bubble array is power efficient and does not require the amount of energy to operate as is required for a motor-driven auto-focus system.

Claims

1. A light-focusing system, comprising:

a lens assembly including at least one focusing lens operable to direct light toward a focal point;

a sensor array disposed adjacent to the lens assembly such that the light through the lens assembly is directed to the sensor array near the focal point; and

a bubble array having a plurality of bubble generators, the bubble array supporting the sensor array, the bubble generators operable to maneuver the supported sensor array with respect to the focal point.

2. The light-focusing system of claim 1 wherein the sensor array further comprises a complimentary metal-oxide substrate having a plurality of active pixel sensors disposed in rows and columns thereon.

3. The light-focusing system of claim 1 wherein the sensor array further comprises a charge-coupled device having a plurality of charge-sensing elements disposed in rows and columns thereon.

4. The light-focusing system of claim 1 wherein the lens assembly further comprises a zoom lens operable to adjust the focal point of the lens assembly.

5. The light-focusing system of claim 1 wherein each of the plurality of bubble generators comprises a resistor disposed below an elastic membrane such that the elastic membrane is inflated to a level proportional to a signal propagated through the resistor.

6. The light-focusing system of claim 5 wherein the signal is an electric signal.

7. The light-focusing system of claim 5 wherein the signal is a thermal signal.

8. The light-focusing system of claim 5, further comprising a processor coupled to the bubble array and operable to control each of the plurality of bubble generators by generating each of the signals that propagate through each of the resistors in each bubble generator.

9. The light-focusing system of claim 8, further comprising an auto-focus circuit operable to collect data from the sensor array, the auto-focus circuit coupled to the processor.

10. The light-focusing system of claim 9 wherein the processor is further operable to control the maneuvering of the sensor array supported by the bubble array based upon an analysis of the data collected by the auto-focus circuit.

11. The light-focusing system of claim 1 wherein the maneuvering of sensor array is based on feedback data collected from and iterative data collection procedure.

12. A method for focusing light onto a sensor array, the method comprising:

focusing light through a lens assembly toward a plurality of sensors in a sensor array, the sensor array supported by an array of bubble generators, each bubble generator having an elastic membrane operable to be inflated based upon a signal propagating through a respective bubble generator resistor;

collecting data about the focused light at the sensor array;

generating an adjustment signal based on an analysis of the collected data; and

adjusting the position of the sensor array by inflating at least one bubble generator, the at least one bubble generator inflated to a level corresponding to the adjustment signal.

13. The method of claim 12 wherein the collecting further comprises collecting data at a first vertical strip of focus sensors and collecting data at a second strip of horizontal focus sensors.

14. The method of claim 12 wherein the adjusting further comprises adjusting the position of the sensor array to be tilted with respect to an image plane of the focused light.

15. The method of claim 12, further comprising:

collecting a second set of data about the focused light at the sensor array;

generating a second adjustment signal based on an second analysis of the second set of collected data; and

adjusting the position of the sensor array by inflating or deflating at least one bubble generator, the at least one bubble generator inflated or deflated to a level corresponding to the adjustment signal.

16. The method of claim 12, further comprising storing the collected data in a memory.

17. The method of claim 12 wherein the analyzing further comprises determines a sharpness factor by comparing the incident light captured at a first sensor to the incident light captured at a second sensor.

18. The method of claim 12, further comprising storing at least a portion of the data collected in a memory.

19. A camera, comprising:

an auto-focus system including;

a lens assembly including at least one focusing lens operable to direct light toward a focal point;

a sensor array disposed adjacent to the lens assembly such that the light through the lens assembly is directed to the sensor array near the focal point; and

a bubble array having a plurality of bubble generators, the bubble array supporting the sensor array, the bubble generators operable to maneuver the supported sensor array with respect to the focal point;

a processor operable to control the auto-focus system by inflating at least one bubble generator.

20. The camera of claim 19 wherein each bubble generator further comprises a resistor disposed below an elastic membrane such that the elastic membrane is inflated proportional to a signal propagated through the resistor.

21. The camera of claim 19, further comprising an analysis circuit operable to analyze the focused light to determine a focus factor such that at least one bubble generator is inflated to a level corresponding to the determined focus factor.

22. The camera of claim 19 wherein the analysis circuit is operable to iteratively determine an optimal level of inflation based upon a repetitive analysis of the directed light.

23. The camera of claim 19 wherein the sensor array comprises a focus strip sensor array and an image capture sensor array.