Pyroelectric detector array with optical filter elements

• US 5,497,003 A
• Filed: 02/15/1995
• Issued: 03/05/1996
• Est. Priority Date: 02/15/1995
• Status: Expired due to Fees

• Current Assignee: Business Alliance Capital Corp. (Banco Santander SA)
• Original Assignee: Servo Corporation of America
• Inventors: Baliga, Shankar B., Rullman, George
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Tyler, Virgil O.
• Application Number:
  US08/389,153
• Time in Patent Office: 384 Days
• Field of Search: 250/338.3, 250/339.14, 250/339.02, 250/339.15, 250/343, 250/349, 250/DIG. 1
• US Class Current: 250/338.3
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0802 Optical filters
• CPC Class Codes: G01J 5/34 using capacitors, e.g. pyroelectric capacitors

Abstract

The apparatus is a pyroelectric detector array with an optical filter. A plurality of pyroelectric detector elements are arranged on a common substrate and an optical filter is placed immediately adjacent to the pyroelectric detector elements. The optical filter includes a plurality of filter elements, each with a preselected optical passband. The optical filter is arranged so that radiation incident on a pyroelectric detector element passes through a respective unique filter element.

Claims

1. A thermal detector comprising:

a substrate;

a plurality of pyroelectric detector elements on said substrate;

electronics on said substrate for interfacing outputs of said plurality of pyroelectric detector elements;

a plurality of optical filter elements, each of said optical filter elements having a different preselected optical passband and corresponding to one of said pyroelectric detector elements; and

means for holding said plurality of optical filter elements immediately adjacent to said pyroelectric detector elements so that incident radiation striking any one of said optical filter elements passes only through to the pyroelectric detector element in correspondence with said one optical filter element and does not pass through to any other of said pyroelectric detector elements of said plurality.

2. The thermal detector of claim 1 further including an optical filter holder which holds all of said optical filter elements and wherein said means for holding comprises a detent means for holding said optical filter holder.

3. The thermal detector of claim 1 further including an optical filter holder which holds all of said optical filter elements and wherein said means for holding comprises a clamping means for holding said optical filter holder.

4. The thermal detector of claim 1 wherein said means for holding includes a clamping means for each of said optical filter elements.

5. The thermal detector of claim 2 wherein said optical filter holder includes an infrared window.

6. The thermal detector of claim 5 wherein said infrared window is comprised of broadband anti-reflection coated germanium.

7. The thermal detector of claim 5 wherein said plurality of pyroelectric detector elements is arranged in a circular configuration.

8. The thermal detector of claim 7 wherein said plurality of pyroelectric detector elements includes eight pyroelectric detector elements.