GB2244145A - Testing apparatus - Google Patents
Testing apparatus Download PDFInfo
- Publication number
- GB2244145A GB2244145A GB9011184A GB9011184A GB2244145A GB 2244145 A GB2244145 A GB 2244145A GB 9011184 A GB9011184 A GB 9011184A GB 9011184 A GB9011184 A GB 9011184A GB 2244145 A GB2244145 A GB 2244145A
- Authority
- GB
- United Kingdom
- Prior art keywords
- split
- collimating
- afocal
- collimated beam
- collimating means
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000003384 imaging method Methods 0.000 claims abstract description 12
- 230000005855 radiation Effects 0.000 claims description 8
- 210000001747 pupil Anatomy 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 2
- 238000011065 in-situ storage Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000001931 thermography Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B17/00—Systems with reflecting surfaces, with or without refracting elements
- G02B17/02—Catoptric systems, e.g. image erecting and reversing system
- G02B17/06—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror
- G02B17/0694—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror with variable magnification or multiple imaging planes, including multispectral systems
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
- G02B19/0004—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed
- G02B19/0009—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed having refractive surfaces only
- G02B19/0014—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed having refractive surfaces only at least one surface having optical power
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
- G02B19/0004—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed
- G02B19/0019—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
- G02B19/0033—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use
- G02B19/0047—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with a light source
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
- G02B19/0033—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use
- G02B19/009—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with infrared radiation
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
- G02B19/0033—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use
- G02B19/0095—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with ultraviolet radiation
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/30—Collimators
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Abstract
Apparatus to test the imaging capabilities of a thermal imager or other similar device by providing a test image of several incident irradiances all obtained from one source, This gives a highly accurate differential irradiance, which is determined by the system geometry and not any external control. A UV or IR source 10 is collimated via mirror 3 and reflected via mirror 4 onto a focal system comprising mirrors 6, 7 of different focal lengths or magnification to produce a narrow bright collimated beam and a broad dim collimated beam which pass through the entrance pupil 2 of the imaging device. Instead of mirrors, lenses may be used (Fig 2). <IMAGE>
Description
TESTING APPARATUS
This invention relates to testing apparatus particularly for testing and/or calibrating imaging devices, for example thermal imaging devices.
Current devices which test the accuracy with which a thermal imager measures temperature, involve the use of one or more internal sources located within the body of the thermal imager. Not only does this increase the cost of production of the thermal imager but relies on the optics remaining constant.
In other words if any of the optics is changed then the system will no longer be calibrated.
One object of the present invention is to provide a simple piece of equipment that can be used in situ and overcomes at least some of the problems described above.
According to one aspect of the present invention there is provided apparatus for testing and/or calibrating an imaging system, comprising:
first collimating means; and split afocal collimating means, wherein in use, the first collimating means collimates the radiation from a source and directs it towards the split afocal collimating means thereby producing collimated beam of variable irradiance.
Preferably the split afocal collimating means comprises two or more split collimating means of different magnification.
Advantageously each split collimating means comprises two or more collimating mirror or two or more collimating lens.
Reference will now be made, by way of example, to the accompanying drawings, in which: - Figure 1 is a diagram of a first embodiment of a test equipment according to the present invention; and
Figure 2 is a diagram of a second embodiment of a test equipment according to the present invention.
Referring to Figure 1 a test equipment shown generally at 1 may be attached to the entrance pupil 2 of an imaging system (not shown per se), to be tested. The imaging system may be a thermal imager, optical camera, UV detector or any other system that may need calibration and/or testing. The test equipment 1 comprises a concave collimating mirror, 3 and a second concave mirror 4, defining a cavity 5 through which radiation can travel.
Located within the cavity is a mirror 20, split into two sectors 6 and 7, each sector being located at opposite sides of the focal axis 8 of the cavity forming part of a split afocal system 9. In use a source of radiation 10 produces a beam of radiation 11.
The beam is directed onto collimating mirror 3 and a collimated beam 12 is generated. This collimated beam is directed to the afocal system. From the afocal system a collimated beam 13 is transmitted into the pupil 2 of the test device. The afocal system is shown having a first mirror 4 and a second mirror split into two sectors 6 and 7 each of differing focal lengths or magnification. It will be appreciated that more than two sectors of differing magnification or focal length may be used in the system if required. The result of using this system is that each sector has differing magnifying powers, resulting in a collimated beam with differing angular subtences and consequently differing irradiances for each sector.
The differing irradiance are as a result of the fact that the different sectors of the mirror 6 and 7 produce respectively a narrow bright collimated beam 13a and a broad dim collimated beam 13b. These beams appear to be of different temperatures due to their relative intensity per m2.
The differences in irradiance between each sector is a function of the respective focal lengths (or magnification of the lenses). This means that the pupil views an image with two or more different intensities depending on the number of lens sectors used.
The differences are used to calibrate or test the imaging system.
It should be noted that this device is intended to provide a radiation calibration and not a spatial calibration, ie, is not a
MRTD type calibrator.
Referring now to Figure 2, a similar system for transmission optics is shown. A beam of radiation 20 from source 10 is collimated by a first lens 21. A second lense 22, part of afocal system, then focuses the beam onto a split lens system 23. The split lens system comprises two collimating lenses 24 and 25 which produce a collimated beam 26 of variable irradiance which is used to calibrate or test the imaging system as described above.
The radiation source which is used in either system is chosen to suit the imaging system under test, and may be UV,
IR or whatever.
This test equipment may be used in situ on any imaging system at any location. NB, using different sources need different lenses and spacings.
The differential irradiance produced by the afocal system is determined by the system geometry, ie ratio of focal lengths and not on external control.
It should be noted that more than two sectors of mirrors or lenses may be used in this invention for example there may be four sectors each occupying a 900 area about the central axis of the system.
Claims (5)
1. Apparatus for testing andlor calibrating an imaging system, comprising:
first collimating means; and split afocal collimating means, wherein in use, the first collimating means collimates the radiation from a source and directs towards the split afocal collimating means thereby producing collimated beam of variable irradiance.
2. Apparatus according to Claim 1, wherein the split afocal collimating means comprising means of two or more different magnifications.
3. Apparatus according to Claim 2 wherein each split collimating means comprises two or more collimating mirrors.
4. Apparatus according to Claim 2 wherein each split collimating means comprises two or more collimating lens.
5. Apparatus for testing and/or calibrating an imaging system, substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9011184A GB2244145B (en) | 1990-05-18 | 1990-05-18 | Testing apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9011184A GB2244145B (en) | 1990-05-18 | 1990-05-18 | Testing apparatus |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9011184D0 GB9011184D0 (en) | 1990-07-04 |
| GB2244145A true GB2244145A (en) | 1991-11-20 |
| GB2244145B GB2244145B (en) | 1994-02-16 |
Family
ID=10676223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9011184A Expired - Fee Related GB2244145B (en) | 1990-05-18 | 1990-05-18 | Testing apparatus |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2244145B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2709563A1 (en) * | 1993-09-02 | 1995-03-10 | Commissariat Energie Atomique | System for focusing high-energy radiation |
| WO1995010793A1 (en) * | 1993-10-15 | 1995-04-20 | Matra Marconi Space France S.A. | Telescope for infrared or visible imaging |
| CN107942510A (en) * | 2017-12-21 | 2018-04-20 | 中国航空工业集团公司洛阳电光设备研究所 | It is a kind of based on the infrared imaging system nonuniformity correction analysis method defocused |
-
1990
- 1990-05-18 GB GB9011184A patent/GB2244145B/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2709563A1 (en) * | 1993-09-02 | 1995-03-10 | Commissariat Energie Atomique | System for focusing high-energy radiation |
| WO1995010793A1 (en) * | 1993-10-15 | 1995-04-20 | Matra Marconi Space France S.A. | Telescope for infrared or visible imaging |
| FR2711251A1 (en) * | 1993-10-15 | 1995-04-21 | Matra Marconi Space France | Telescope for infrared or visible imaging. |
| US5661610A (en) * | 1993-10-15 | 1997-08-26 | Matra Marconi Space France S.A. | Telescope for infrared or visible imaging |
| CN107942510A (en) * | 2017-12-21 | 2018-04-20 | 中国航空工业集团公司洛阳电光设备研究所 | It is a kind of based on the infrared imaging system nonuniformity correction analysis method defocused |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2244145B (en) | 1994-02-16 |
| GB9011184D0 (en) | 1990-07-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Lantz et al. | SNIFS: a wideband integral field spectrograph with microlens arrays | |
| US7787132B2 (en) | Method and arrangement for a rapid and robust chromatic confocal 3D measurement technique | |
| US7333216B2 (en) | Apparatus for wavefront detection | |
| US10245683B2 (en) | Apparatus and method for beam diagnosis on laser processing optics | |
| US5835217A (en) | Phase-shifting point diffraction interferometer | |
| US4272190A (en) | Optical measuring system | |
| CA2033194A1 (en) | Wavelength detecting apparatus | |
| US4620790A (en) | System for determining optical aberrations of a telescope optical system | |
| US4824243A (en) | Compact continuous wave wavefront sensor | |
| US6075612A (en) | Optical devices having toroidal mirrors for performing reflectance measurements | |
| Tyson et al. | LSST optical beam simulator | |
| JP2001281101A (en) | Device and method for determining refracting power by spatial resolution | |
| US6023057A (en) | Device for determining the phase errors of electromagnetic waves | |
| GB2244145A (en) | Testing apparatus | |
| Küsters et al. | SCALA upgrade: development of a light source for sub-percent calibration uncertainties | |
| Dittrich et al. | Measurement principle and arrangement for the determination of spectral channel-specific angle dependencies for multispectral resolving filter-on-chip CMOS cameras | |
| Ren et al. | Optical design of a high-order adaptive optics for the NSO Dunn Solar Telescope and the Big Bear Solar Observatory | |
| Ohtani et al. | Kyoto tridimensional spectrograph I | |
| Costa et al. | PYRAMIR: a near-infrared pyramid wavefront sensor for the Calar Alto adaptive optics system | |
| US6717676B2 (en) | Method for measuring magnification of an afocal optical system | |
| Li et al. | Telescope alignment based on the structured lighting of collimated laser beam bundles | |
| Green et al. | Interferometric validation of image-based wavefront sensing for NGST | |
| Gleckler et al. | WM Keck Observatory adaptive optics program | |
| RU2082992C1 (en) | Cosmic telescope (versions) | |
| RU2046303C1 (en) | Optical pyrometer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19940518 |