Classifications

• • 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
  • G02B27/64—Imaging systems using optical elements for stabilisation of the lateral and angular position of the image
  • G02B27/646—Imaging systems using optical elements for stabilisation of the lateral and angular position of the image compensating for small deviations, e.g. due to vibration or shake

Definitions

• the present invention refers to a stabilized-image optical in ⁇ strument, such as telescopes and cameras.
• the optics is dimensioned so that the stabilized ele- ment functions as a "reference element", i.e. the telescope image follows the turning movements of said element. If this element is stabilized, the image also appears stabilized.
• the purpose of the present invention is, among other things, to realize monocular and binocular instruments with image sta- bilization without any of the disadvantages mentioned above.
• An advantage of the invention- is that the objective is stabil ⁇ ized which has as a result that the introduction of image sta ⁇ bilization makes no further demand on the objective, compared to an unstabilized instrument; accordingly, standard objectives may be used with advantage.
• the optics may be varied in a great many different ways. Only the four reflecting surfaces needed for image reversal are necessary in the simplest construction of telescopes.
• the stabilized part has a high moment of inertia in relation to the length of the instrument.
• the pivot point can be placed both within and outside the beam of rays from the objective, which results in the greatest freedom in the choice of bearing being obtained.
• a simple type of stabilized binoculars is made possible with ⁇ out the disadvantages from which other structures of similar types have suffered up to now.
• angular deflection The angle which the telescope casing is turned at a certain moment in relation to the stabilized part is here referred to as angular deflection , when the angular deflectionequals zero, the stabilized part is in its central position.
• optical cal axis is henceforth meant the line which is defined by the optical axis of the objective lens system when the angular de ⁇ flectionequals zero.
• the stabilized part of optics constructed according to this invention has a high moment of inertia in relation to the length of the instrument, the firstmentioned simpler method of stabilization without a gyro is very suitable here.
• Figures 1 to 3 show the principle of the invention app ⁇ lied to a telescope.
• Figure 4 diagrammatically shows the use of a certain type of optical elements in a telescope.
• Figure 5 shows an element included therein.
• Figure 6 diagrammatically shows the use of a second type of optical elements and Figure 7 another type of optical elements in connection with the in ⁇ vention, and
• Figures 8 and 9 diagrammatically show the inven ⁇ tion applied to a pair of binoculars
• Figure 10 shows an al ⁇ ternative to the latter
• Figure 11 shows another alterna ⁇ tive to the application of the invention in the case of a pair of binoculars.
• the general principle of the present invention is explained in connection with Figures 1, 2 and 3 diagrammat ⁇ ically showing the invention in connection with a telescope.
• the stabilized part consists of the objective lens 1 together with the optical element 2 which may consist of any conceiv ⁇ able combination of lenses, prisms, mirrors and the like, but a requirement is that the element contains at least one re ⁇ flecting surface. It should be noted that this stabilized part is the most important one for the invention. Its form can be varied in a great many different ways and other opti ⁇ cal elements may be added, but this part is found in some form or other in all variants.
• the objective 1 and the optical element 2 are rigidly fixed to each other by an arm or bridging member 3 to which two suitab ⁇ ly dimensioned counterweights 4 and 5 may advantageously be fixed.
• a second optical element 6 is, like the ocular 9, ri- gidly fixed to the casing 7 of the telescope and is according ⁇ ly unstabilized. Light rays from an observed object first pass es the protective plane window 8 and then the objective 1, thereupon passes the elements 2 and 6 and finally the ocular 9
• the stabilized p * art is rotatably mounted, substantially with- out friction, at a pivot point 30 (not shown in Figure 1) , the exact position of which will be discussed later.
• freedom of rotation exists about all axes at right angles to the visual line but not around the latter. The function in general is best understood if Figure 2 is considered which shows the same telescope as
• FIG 4 the essential parts of a telescope are shown, where a threefold reflecting prism 10 is included, shown more in de ⁇ tail in Figure 5.
• This element has the property of reflecting the light non-rotated about the optical axis 11 like a plane mirror but translated the length E, provided that the reflect- ing planes 12, 13 and 14 are oriented such that each of them contains a line which is parallel to a line in the other planes.
• the U.S. patent No. 3 475 073 is referred to in which other alternative elements with equivalent optical properties are also shown.
• a plane mirror 15 and a roof prism 16 are included which are oriented so that the three reflecting sur ⁇ faces thereof are at right angles to each other. These sur ⁇ faces essentially form a cube corner, and henceforth the plane mirror 15 and the roof prism 16 will, accordingly, to- gether be regarded as a cube corner element 17.
• the telescope shown in Figure 4 has exactly the same fundamental construction as the one described in connection with Figures 1 and 2; the threefold reflecting ele- ment 10 in Figure 4 thus corresponds to the element 6 in Fi ⁇ gure 1, and the cube corner element 17 in Figure 4 corresponds to the element 2 in Figure 1. Consequently, in the case of di ⁇ mensioning for camera stabilization the pivot point is to be placed where the focus of the objective would have been in the absence of the unstabilized prism 10, point A.
• the light is reflected six times between objective and ocular. This may seem to be an unnecessary complexity compared, for example, to a porro system where only four reflections occur.
• image stabilization according to this invention, which is described in connection with Figure 6.
• the essential parts of a telescope are shown, containing four mirrors arranged in a well-known way for image reversal.
• the two mirrors 21 and 22 at right angles to each other are rigidly connected to the objective 1, said combination being stabilized.
• the mirrors 24 and 25 at right angles to each other are fixed to the casing (not shown) and are thus unstabilized.
• the stabilized part alone must thus be balanced around->an_ ⁇ xis j V - ⁇ — .
• the stabilized part, together with the part of the bearing which is stabilized around only one axis, corresponding to the "middle part" of a cardan ring, must be balanced about the other axis.
• the pivot axis 26, which is parallel to the in- tersecting line 28 of the unstabilized mirrors, is to be placed so that the axis 26 goes through point B
• the pivot axis 27, which is parallel to the intersecting line 29 of the sta ⁇ bilized mirrors is to be placed at point C.
• the two pivot axes 26 and 27 are thus to be placed at the distance f .
• dimensioning for camera stabilization is not suitable, other methods may be used where the disadvant ⁇ age of separate pivot axes is avoided.
• Dimensioning for tele ⁇ scope stabilization need not be brought about here by moving the pivot point or both pivot axes from the point realizing dimensioning for camera stabilization but, for example, by placing a lens (or several lenses) such that the requirement that light from an observed object first is to pass only ful ⁇ ly stabilized optics and then is to pass only unstabilized optics is not satisfied (the flat covering disc in front of the objective is neglected) .
• a ne- gative lens stabilized about one or two axes can be placed so that the light passes this lens before it passes the ocular, or the flat covering disc in front of the objective may be re- placed by a positive lens which, if desired, may form part of' the objective lens system.
• the pivot point generally can ⁇ not be placed exactly on line L.
• Still another method of realizing dimensioning for telescope stabilization in structures where the pivot point is placed for camera stabilization should be mentioned.
• This method is aimed at getting the stabilized part, by servo mechanisms or other means, to move with a certain fraction of the turning move ⁇ ments of the casing so as in this way to modify the degree of stabilization with a certain factor.
• the stabilized part consists of the two objectives 1', I 11 and the mirrors 46, 47, 52 and 53.
• This unit has a cardan mounting at the pivot point A which is placed for exact camera stabilization of» the two parts of the binoculars; consequently, the focal points of the two objectives, where they would have been without the mirrors 48, 49, 55 and ' 56, meet at the same point where the pivot point A is situated.
• the optical axes are here wholly in the same plane, the horizontal plane, before reflection occurs in the unstabi- lized mirrors.
• This part consists of an ocular together with corresponding unsta ⁇ bilized pairs of mirrors, and this combination is rotatable a- round a vertical axis placed for telescope stabilization. If the right ocular 9'- is chosen to be adjustable, this ocular and the mirrors 48 and 49 thus have to be rotatable as a unit a small angle around the vertical axis 58 ( Figure 8) which in ⁇ tersects line L and the distance of which to the pivot point A has to be as large as the focal length f , of the ocular.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Telescopes (AREA)

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• 1981
  • 1981-06-25 SE SE8103984A patent/SE426883B/sv not_active IP Right Cessation
• 1982
  • 1982-06-18 AU AU85853/82A patent/AU8585382A/en not_active Abandoned
  • 1982-06-18 US US06/474,583 patent/US4542962A/en not_active Expired - Lifetime
  • 1982-06-18 JP JP57502034A patent/JPS58501147A/ja active Granted
  • 1982-06-18 WO PCT/SE1982/000222 patent/WO1983000067A1/en active IP Right Grant
  • 1982-06-18 EP EP82901993A patent/EP0082178B1/en not_active Expired
  • 1982-06-18 DE DE8282901993T patent/DE3274768D1/de not_active Expired

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