Intertwined beam path
An interwoven beam path (also a chained beam path ) is used in technical optics primarily for imaging devices with an artificial light source. These devices are essentially projection devices and microscopes . The interdependence exists between the upstream lighting device and the imaging device :
- The hatches of the illumination beam path coincide with the pupils of the imaging beam path .
- The pupils of the illumination beam path coincide with the hatches of the imaging beam path.
This type of interweaving has the effect that the evenly artificially illuminated object is reproduced with maximum brightness.
Intertwined beam path in a projector, for example
Intertwined beam path of a projector :
left: illuminating beam path ( B ); right: imaging beam path ( A ).
Meaning of the other letters:
R = reflector (R)
L = light source (yellow)
K = condenser with aperture d K and the main plane of the illumination beam path H B in object distance g B
G = object to be imaged with diameter d G in object distance g A
O = objective with the main plane of the imaging beam path H A in the image distance b B
P = projection plane with a real image with the diameter d P in the image distance b A
left: illuminating beam path ( B ); right: imaging beam path ( A ).
Meaning of the other letters:
R = reflector (R)
L = light source (yellow)
K = condenser with aperture d K and the main plane of the illumination beam path H B in object distance g B
G = object to be imaged with diameter d G in object distance g A
O = objective with the main plane of the imaging beam path H A in the image distance b B
P = projection plane with a real image with the diameter d P in the image distance b A
The beam path in a projector consists of two individual beam paths:
- Imaging beam path ( A ): in the imaging system , consisting of the object to be imaged (G), an objective (O) and the upside-down, real image on a projection screen (P),
- Illumination beam path ( B ): in the illumination system , consisting of a light source (L) (advantageously additionally with a reflector (R)), the object to be imaged (G) and a condenser (K).
For an optimal projection, the two beam paths must be interwoven:
- The exit hatch of the illumination beam path coincides at location H A with the entrance pupil of the imaging beam path .
- The exit pupil of the illumination beam path at location H B approximately coincides with the entrance hatch of the imaging beam path at location G. The interweaving is the better the closer the object to be imaged (G) is to the condenser (K).
literature
- Gottfried Schröder: Technical optics . 5th edition. Vogel-Buchverlag, Würzburg 1986, ISBN 3-8023-0067-X , Chapter 6.2.1: Overview of lighting systems , pp. 113/114
Web links
Wikibooks: Digital imaging methods - dimensioning an interwoven beam path - learning and teaching materials
- Bernd Leuschner: Chained beam path (PDF; 122 kB) Laboratory for device technology, optics and sensors, Beuth University of Technology Berlin
Individual evidence
- ↑ a b Dietrich Kühlke: Opti - Basics and Applications . Harri Deutsch, Frankfurt / Main, 2011, ISBN 978-3-8171-1878-6 , p. 151
- ↑ Ludwig Bergmann , Clemens Schaefer : Textbook of Experimental Physics , Volume III: Optics , Chapter I, 12: Radiation Optics - The Eye and Some Optical Instruments . 7th edition. Verlag Walter de Gruyter, Berlin / New York 1978, pp. 158/159