Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
  • G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
  • G02B7/026—Mountings, adjusting means, or light-tight connections, for optical elements for lenses using retaining rings or springs

Definitions

• the invention relates to an arrangement for fixing components of an optical system, such as lenses, mounting rings, spacing disks and the like, which are enclosed by a common tube in which they are guided radially and are held elastically in the axial direction under prestress.
• a first part is generally in contact with a fixed system; the last component is a spring-loaded functional part, e.g. a rubber ring, over the edge area and fixes the parts in their position.
• a spring-loaded functional part e.g. a rubber ring
• the elastic holder is characterized in that a ring made of rubber-like material is arranged in an annular groove in the holder body; the annular groove is partially covered in the axial direction by the lens circumferential surface.
• the space between the lens and the holder body, intended for the ring, is widened outwards.
• the lens is held as an individual part between a fixed annular stop formed integrally on the frame body and the rubber ring; the pretensioning force exerted by the elastically deformed rubber ring is transmitted to the socket body via the annular stop on the one hand and via the contact surface of the rubber ring on the other hand.
• this solution only compensates for length changes and differences for one component, the lens.
• Another disadvantage is that with this holder a change in the magnitude of the pretensioning force in defined steps, as is desirable for special optical systems, is not possible since the position of the rubber ring is fixed unchangeable with the position of the groove . If no groove is provided (in the case of a frictional connection to the frame body), the pretensioning force is dependent on the friction between the rubber and the cylindrical wall of the frame body, which is influenced by numerous factors, and consequently likewise cannot be changed in a defined manner.
• DE OS 23 62 041 describes a version in which a lens or lens group is held in its version by means of a screw-in ring.
• the ring has elastic projections, which serve as an abutment for the lens group and hold it under elastic prestress.
• the magnitude of the pretensioning force can be changed here with the screw-in depth of the ring, it is disadvantageous that the thread is complex in terms of production technology and the assembly of the optical system is time-consuming.
• the object of the invention is to provide an arrangement for fixing components of an optical system in the axial direction, in which the pretensioning force with which the components are held elastically against a stop can be changed in determinable steps.
• the arrangement should be inexpensive to manufacture and easy to assemble.
• the locking elements of the mounting ring can be brought into engagement with the locking elements on the tube under the action of an axially directed force on the fastening ring, and the locking elements can be released from this engagement in the opposite direction of force action. Due to the areal distribution of the locking elements on the circumference of the fastening ring and tube, there is a large number of locking positions in the axial direction, so that the pretensioning force which the fastening ring exerts on the components to be held depends on the extent of coverage of the locking elements on mounting ring with the catch ⁇ lementen on the tube dependent. In other words: the preliminary tension increases with the path that the fastening ring is pushed towards the stop in the direction; conversely, it decreases the further the fastening ring is moved away from the stop in the locking engagement.
• the locking elements on the relevant peripheral surfaces on the fastening ring and on the tube should have a gable roof-shaped cross section.
• the angles of inclination of the roof-shaped surfaces can be different with respect to the optical axis, so that the force required for latching is different from the force required for releasing the latching connection.
• the latching elements on the fastening ring can extend radially over the entire circumference of the relevant section of the circumferential surface; independently of this, the latching elements on the tube can also extend over the entire circumference of the relevant section of the circumferential surface.
• Fig.l an optical system with two embodiment variants of the invention 2 shows an enlarged cross section of the locking elements
• Fig.l an optical system with the tube 1, the lenses 2 to 5 and a spacer ring 6 is shown.
• the lenses 2 and 3 and the intermediate ring 6 are axially lined up on one side to a f ⁇ sten, integrally formed on the tube 1 stopper 7, and are ande hand, with a releasable attachment rings 8 voltage under prestress against the Stop 7 held.
• the fastening ring 8 is made of elastic material and extends radially over the edge of the lens 2. Both the fastening ring 8 and the tube 1 each have a circumferential surface that is oriented concentrically to the optical axis and extends over the area B, Detent elements 9 and 10, which are designed as corresponding locking elements.
• the detent elements 9 are distributed in the area B ⁇ on the fastening ring 8 over the entire circumferential surface; the locking elements 10 are also distributed over the entire circumferential area in the area B 2 on the tube, as a result of which there is a large number of locking positions in the axial direction.
• the number of locking positions per unit length depends on the geometric size of the individual locking elements.
• each of the locking steps of the fastening ring 8 in the axial direction towards the stop 7 brings about a defined increase in the pretensioning force which the fastening ring 8 exerts with its inner edge on the components to be held (lens 2, spacer ring 6, lens 3).
• each locking step by which the fastening ring 8 is displaced in the axial direction away from the stop 7 means a defined reduction in the pretensioning force.
• the lenses 4 and 5 are on both sides of the mounting rings 11 and 12.
• the fastening rings 11 and 12 are also made of an elastic material and, with their inner diameters, engage radially over the edges of the lenses 4 and 5 facing them.
• the fastening rings 11 and 12 and the tube 1 each point to one another Circumferential surfaces, which are aligned concentrically to the optical axis, have latching elements which, analogous to the first embodiment variant, are designed as corresponding locking elements. These locking elements are also distributed over a large area, as a result of which there is a large number of locking positions in the axial direction. The number of locking positions per unit length is also dependent on the geometric size of the individual locking elements.
• a gradual simultaneous displacement of the two fastening rings 11, 12 in this variant causes a change in the positions of the lenses 4, 5 in the axial direction, while the prestressing force with which the lenses 4, 5 are held between the fastening rings 11, 12, remains constant. If one of the two fastening rings 11 or 12 is moved towards the other in latching steps, the increases with each latching step Prestressing by a defined amount. Conversely, the preload is reduced when one of the two fastening rings 11 or 12 is moved away from the other.
• the main advantages of the invention are that the proposed arrangement on the one hand compensates for length deviations in the axial direction, but on the other hand also an increase or decrease in the pretension and, as shown in the second embodiment variant, permits displacement of components, the Preload at the new location of the components is as great as at the previous location. There is also a series-friendly manufacturing and assembly option.
• Fig.2 locking elements are shown enlarged, which are formed with a saddle roof cross-section.
• the angles of inclination of the roof-shaped surfaces 13 and 14 are different with respect to the optical axis. Due to the lower inclination of the roof-shaped surface 13, a smaller force is required to move in the locking direction K E than to release the latching connection in the opposite direction K L , since the greater inclination of the roof-shaped surface 14 must be overcome here.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Lens Barrels (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=7796735

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• 1996
  • 1996-06-12 DE DE19623426A patent/DE19623426A1/de not_active Ceased
• 1997
  • 1997-06-05 US US09/000,412 patent/US5926326A/en not_active Expired - Fee Related
  • 1997-06-05 EP EP97929150A patent/EP0843835A1/de not_active Withdrawn
  • 1997-06-05 JP JP10501161A patent/JPH11510921A/ja active Pending
  • 1997-06-05 WO PCT/EP1997/002928 patent/WO1997048000A1/de not_active Application Discontinuation

Non-Patent Citations (1)

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