Microcontroller-based imaging system utilizing a CMOS image sensor array

• US 7,990,544 B2
• Filed: 05/22/2009
• Issued: 08/02/2011
• Est. Priority Date: 05/27/2008
• Status: Expired due to Fees

• Current Assignee: Trent University
• Original Assignee: Trent University
• Inventors: Ugray, Matthew David Roberts, Philippson, Jeffrey Nicholas, Shiell, Ralph Charles
• Primary Examiner(s): Connolly; Patrick J
• Application Number:
  US12/453,834
• Publication Number:
  US 20090296104A1
• Time in Patent Office: 802 Days
• Field of Search: 356/454, 356/480, 356/519
• US Class Current: 356/519
• CPC Class Codes: G01J 1/4257 applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam monitoring arrangements for lasers in general H01S3/0014
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G01J 3/2803 using photoelectric array detector

Abstract

Described herein is a an optical sensing unit, the optical sensing unit including a one-dimensional array of sensor locations, each sensor location being responsive to an incident optical signal to generate a local analog intensity value representative of the intensity of the optical signal at the sensor location, the sensing unit including a digital interface to deliver a local digital intensity value corresponding to the local analog intensity value, a first microcontroller function in communication with the digital interface for sequentially collecting local digital intensity values to form a group of digital intensity values corresponding to an intensity variation across the array over a predetermined sensing period, a second microcontroller function cooperating with the first microcontroller function to receive the group of digital intensity values for transfer to an output device.

Claims

1. An imaging system comprising an optical sensing unit, with a plurality of sensor locations, each sensor location being responsive to an incident optical signal to generate a local analog intensity value representative of the intensity of the optical signal at the sensor location, the sensing unit including a digital interface to deliver a local digital intensity value corresponding to the local analog intensity value, a first microcontroller function in communication with the digital interface for sequentially collecting local digital intensity values to form a group of digital intensity values corresponding to an intensity variation across the array over a predetermined sensing period, a second microcontroller function cooperating with the first microcontroller function to receive the group of digital intensity values for transfer to an output device.

2. A system as defined in claim 1, the plurality of sensor locations being oriented in a one dimensional array.

3. A system as defined in claim 1, the output device including a display unit or a data storage unit.

4. A system as defined in claim 3, the data storage unit including a computer or a storage device.

5. A system as defined in claim 3, the display unit including a liquid crystal display.

6. A system as defined in claim 5, the liquid crystal display having a plurality of rows and columns, a driver function to scan the display grid progressively by row, each row corresponding to a sensor location or consecutive group of sensor locations, to display a marker on each row at a position corresponding to the intensity of the optical signal at the sensor location or consecutive group of sensor locations, the liquid crystal display being oriented to display the intensity values as a horizontal trace.

7. A system as defined in claim 1, the first and second microcontroller functions being provided by corresponding first and second microcontroller units.

8. A system as defined in claim 7, further comprising a data transfer bus between the first and second microcontroller units.

9. A system as defined in claim 8, the data transfer bus utilizing a transfer synchronization protocol.

10. A system as defined in claim 9, the transfer synchronization protocol being implemented using a first signal line and a second signal line, the protocol including a first mode in which the second microcontroller is a receiver and sets the first signal line to logic-high indicating a request for data, a second mode in which the first microcontroller is a sender and places data on the data transfer bus, the sender setting the second signal line to logic-high indicating that data has been placed on the data transfer bus, the receiver reading data from the data transfer bus, the receiver setting the first signal line to logic-low indicating that data has been received, the sender setting the second signal line to logic-low to ensure that the same data value is not retransferred on the next request from the receiver.

11. A system as defined in claim 10, the image sensing unit and the microcontrollers being configured to transfer instructions for changing system parameters.

12. A system as defined in claim 8, the first and second microcontroller units operating on independent clock frequencies.

13. A system as defined in claim 8, the first and second microcontroller units operating on a common clock frequency or otherwise dependent clock frequencies.

14. A system as defined in claim 8, the first and second microcontroller units operating at the same voltage, that voltage defining the logic-high level for exchanging data between the optical sensing unit and the first microcontroller, exchanging data between the two microcontroller units on the data transfer bus, and exchanging data between the second microcontroller unit and an output device.

15. A system as defined in claim 8, the first microcontroller unit operating at a voltage determined by the requirements of the optical sensing unit, the second microcontroller unit operating at a voltage determined by the requirements of the output device, the data transfer bus including digital logic signals at both voltages utilizing the wide input voltage ranges of the microcontrollers.

16. A system as defined in claim 1, the optical sensing unit having a sensitivity that is adjusted by a user according to a power level of the incident optical signal.

17. A system as defined in claim 16, the optical sensing unit having a plurality of configuration registers including window height and row start for windowing, and shutter width for pixel integration time, the registers being adjusted according to measured characteristics of the incident optical signal, the registers being accessible to the user.

18. An imaging system as defined in claim 1, further comprising a dispersive device positioned at an upstream location relative to the optical sensing unit, on an optical path to receive an incident light beam, the optical sensing unit being positioned at a downstream location to receive an incident optical interference pattern from the dispersive device thereon, the optical sensing unit being oriented to register intensity values with positions corresponding to different wavelengths present or absent in the incident light beam, the digital intensity values collected by the first microcontroller function representative of the intensity variation across the sensor locations corresponding to the wavelength content of the light beam within a particular range of wavelengths.

19. An imaging system as defined in claim 18, the dispersive device including a transmissive or reflective diffraction grating, or a prism, or a Fabry-Perot or Fizeau interferometer.

20. A method of imaging an optical signal, comprising providing a plurality of sensor locations, each sensor location being responsive to an incident optical signal to generate a local analog intensity value representative of the intensity of the optical signal at the sensor location, providing a digital interface to deliver a local digital intensity value corresponding to the local analog intensity value, providing a first microcontroller in communication with the digital interface, configuring the first microcontroller to sequentially collect local digital intensity values to form a group of digital intensity values corresponding to an intensity variation across the array over a predetermined sensing period, providing a second microcontroller to receive the group of digital intensity values, and configuring the second microcontroller to transfer to the group of digital intensity values to an output device.