Optical: systems and elements – Mirror – Plural mirrors or reflecting surfaces
Patent
1991-12-06
1994-09-13
Henry, Jon W.
Optical: systems and elements
Mirror
Plural mirrors or reflecting surfaces
359900, 359858, G02B 510
Patent
active
053474015
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to a reflecting telescope with a tube and a primary mirror located therein, the focal point of the primary mirror being located outside the tube, as well as to a process for the production thereof.
BACKGROUND OF THE INVENTION
Reflecting telescopes are known, in which the optical axis of the primary mirror is parallel to the tube or the light incidence direction. The adaptive optics with the reflecting mirror are located in the focal point in the light incidence area, which leads to shading.
In addition, Wilhelm Herschel discloses a reflecting telescope, whose rotationally symmetrical primary mirror is sloped with respect to the light incidence direction in such a way that the focal point is located outside the tube, so that the adaptive optics can be positioned outside the incidence of light. However, as a result of the mirror slope the light paths differ, which leads to astigmnatic image distortions. Thus, a correcting plate ,must be used for compensating the different light paths.
SUMMARY AND OBJECTS OF THE INVENTION
The problem of the present invention solves, is to provide a reflecting telescope of the aforementioned type, in which the effective radiation incidence area is kept free from optical functional elements, such as e.g. the reflecting mirror with its mounting and the like, but the focal point can still be sufficiently specifically fixed to ensure that no correcting optics are required.
This problem is solved in that the surface of the primary mirror is shaped as a pitch circular surface of a hypothetical, rotationally symmetrical large mirror, whose optical axis is positioned alongside the pitch circular surface and is parallel to the light incidence direction.
Thus, the invention is based on the idea that a hypothetical, rotationally symmetrical large mirror, which cannot be manufactured as a result of its dimensions, has a focal point located in the optical axis, which is free from astigmatic distortions and the like. However, this focal point is not only decisive for the complete large mirror surface, but also for all partial surfaces. Thus, on restricting to a partial surface of the large mirror displaced with respect to the optical axis and which can be obtained as a result of the proportions, then the associated focal point must be located outside the light incidence tube without this leading to optical disadvantages.
Thus, for example, a circular partial surface according to the invention positioned alongside the optical axis has the same intensity distribution of the incident radiation energy in the focal point as a rotationally symmetrical, polished, circular mirror with the same diameter, whose focal length corresponds to that of the inventive partial surface. This means that for an incidence bundle of beams it is completely unimportant whether it strikes a rotationally symmetrical, polished primary mirror, whose optical axis is identical to the rotational axis of symmetry, or a partial surface located alongside the optical axis, whose diffraction aperture considered in the light radiation incidence direction is identical with the diffraction aperture of the rotationally symmetrical, polished mirror. All that is important is the length of the light path to the focal point, so as to occur there in an in-phase manner. This condition is fulfilled with the partial surface according to the invention. It is a surface cutout of the large mirror and therefore images in completely distortion-free manner.
The invention has the advantage that with respect to the adaptive optics and the associated functional elements, no constructional limitations exist, because they are located outside the light/radiation incidence area and therefore neither cause shading, nor project into the reflection field. As the focus of the primary mirror is kept free or undergoes no restriction in its action, a completely lossless light concentration in the focus of the primary mirror is possible.
Fundamentally the primary mirror can be constructed as a monolith. Howev
REFERENCES:
patent: 1428935 (1922-09-01), Bell
patent: 3502387 (1970-03-01), Hudley
patent: 3507547 (1970-04-01), Thomas
patent: 3588270 (1971-06-01), Wells
patent: 4902102 (1990-02-01), Breidenthal
patent: 4928435 (1990-05-01), Masaki et al.
patent: 4974368 (1990-12-01), Miyamoto et al.
patent: 4993190 (1991-02-01), Hiyoshi et al.
R. E. Sladky et al., "Fabrication of Off-Axis Parabolic Mirrors", Optical Eng., vol. 17, No. 6, pp. 588-594, Nov.-Dec. 1978.
Henry Jon W.
Hugenell Hermann
Karl Friedrich Angstenberger
LandOfFree
Reflecting telescope and its production process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reflecting telescope and its production process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reflecting telescope and its production process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1124489