# US 6,825,978 B2 · High sensitivity thermal radiation detection with an emission microscope with room temperature optics

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 6,825,978 B2
- Document ID: US6825978B2
- Status: Granted
- Kind: B2
- Application number: 10/397,914
- Filed: 2003-03-25
- Published: 2003-11-27
- Granted: 2004-11-30
- Earliest claimed: 2002-04-04
- Assignees: Hypervision, Inc.
- Inventors: Neeraj Khurana; Prasad Sabbineni; Andrew Sabersky
- Web page: https://patentgrep.com/patent/US6825978B2

## CPC

- G02B 21/0004: {specially adapted for specific applications}
- G02B 21/362: {Mechanical details, e.g. mountings for the camera or image sensor, housings (G02B21/364 takes precedence)}
- H04N 23/23: from thermal infrared radiation
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A light emission microscope includes a low temperature detector array which receives light through a room temperature projection optics system from a device under test. A cold aperture including a movable cold stop and a cryogenic filter absorbs unwanted thermal radiation emitted by the optics system. In one embodiment, a high resolution CCD camera can be used with the low temperature detector array and camera with a computer-controlled mirror providing emitted light to both cameras.

## Claims

### Claim 1

A microscope comprising:
a Low Temperature Detector array which outputs an electronic signal proportional to the thermal radiation above 1.5 μm;
Multiple Objective Lenses for imaging thermal radiation emitted by a device under test and to project an Intermediate image, different objective lenses having different magnifications;
a Projection Lens system for imaging the Intermediate image on to the detector array;
a Cold Aperture which is a limiting aperture of the system, located between the projection lens system and the detector array, the said cold aperture absorbing the unwanted thermal radiation emitted within the optical system, and the cold aperture located at a plane conjugate with the exit stop of the objective lens;
a Cold Optical Filter means which blocks unwanted wavelengths from imaging on the array;
a Processor means coupled to the low temperature detector array for removing noise and enhancing the signal; and
a Display means coupled to the processor means for displaying a thermal image of the heat emitted by the device under test.

### Claim 2 (depends on 1)

A microscope of claim 1 where the low temperature filter blocks thermal radiation above 2.2 μm.

### Claim 3 (depends on 1)

A microscope of claim 1 with a low temperature filter which passes radiation between 1.5 μm and 2.2 μm.

### Claim 4 (depends on 1)

A microscope of claim 1 where the low temperature filter block thermal radiation above 1.8 μm.

### Claim 5 (depends on 1)

A microscope of claim 1 with a low temperature filter which passes radiation between 1.5 μm and 1.8 μm.

### Claim 6 (depends on 1)

A microscope of claim 1 with movable means allowing multiple cold filters.

### Claim 7 (depends on 6)

A microscope of claim 6 where the Detector Array is sensitive to non thermal radiation (<1.3 μm).

### Claim 8 (depends on 7)

A microscope of claim 7 with through the lens illumination means for short wavelengths (<1.3 μm) allowing high resolution reflected light images, which can be superimposed on the thermal image acquired through the same objective lens.

### Claim 9 (depends on 1)

A microscope of claim 1 with movable means allowing multiple cold apertures which are optimized for each objective lens.

### Claim 10 (depends on 1, 9)

A microscope of claim 9 in which the Multiple Objective Lenses of claim 1 include a Macro Lens for obtaining a global view of the device with a high numerical aperture (>0.05), as well as Microscope Lenses which provide high magnification for viewing sub areas of the device.

### Claim 11 (depends on 10)

A microscope of claim 10 where the macro objective lenses comprises two back to back lenses with a high numerical aperture (>0.1).

### Claim 12 (depends on 11)

A microscope of claim 11 with a low temperature filter which block thermal radiation longer than 2.2 μm.

### Claim 13 (depends on 12)

A microscope of claim 12 where the low temperature filter passes radiation between 1.5 μm and 2.2 μm.

### Claim 14 (depends on 11)

A microscope of claim 11 with a movable low temperature filter which blocks radiation longer than 1.8 μm.

### Claim 15 (depends on 12)

A microscope of claim 12 with low temperature filter which passes radiation between 1.5 μm and 1.8 μm.

### Claim 16 (depends on 10)

A microscope of claim 10 with movable means allowing multiple cold filters.

### Claim 17 (depends on 16)

A microscope of claim 16 where the Detector Array is sensitive to non-thermal radiation (<1.3 μm).

### Claim 18 (depends on 17)

A microscope of claim 17 with through the lens illumination means for short wavelengths (<1.3 μm) allowing high resolution reflected light images, which can be superimposed on the thermal image acquired through the same objective lens.

### Claim 19 (depends on 10)

A microscope of claim 10 with movable means allowing multiple cold apertures which are optimized for each objective lens.