DE2650806A1 - Microfilm reader system with revolving turret - has two lenses for high magnification of projected image - Google Patents

Abstract

A microfilm reader has a lens turret which hovers over the film plate such that it has a constant distance from the microfilm. This distance can be adjusted with precision with the help of the focussing knob if required. A horizontal plate which can move against a point is fixed to the equipment. There is a cover glass plate and lower glass plate which encases the film, and can be adjusted as a single unit. By using a handle, first or second lens mounted on the turrent can be brought into play within the optical aixs of the system. An eccentric rod parallel to the handle is housed in a block which has a focussing knob at its end. The hollow rod connected to shaft has a nut in the hollow shell which moves by rotating the shaft. This causes the turret to move up or down relative to the position of the plate.

Description

OBJECTI VREVOLVER

The invention relates to an objective nosepiece as used in reading devices for micro-plan film, especially for large enlargements.

It is state of the art that in microfilm readers with medium Magnifications two or more lenses in one, pivotable around one point Disc (revolver) are taken and alternately by rotating the disc in cover brought with the optical axis of the lighting system and projection system can be. The disadvantage of such devices is that with short focal lengths Lenses cause slight changes in the distance between the original film and the lens Already lead to blurring due to mechanical tolerances of the film carrier. Further It is known, and state of the art, that single lenses are used in plan film devices I floating "above the film, i.e. with their frame directly on top slide on the cover glass plate located over the film and so keep it constant Distance between lens and film guaranteed.

The present invention was based on the object of an objective nosepiece to create which lischwimmendil arranged over the film and its cover glass plate is.

In order to solve this problem, a swiveling device in relation to the reading device was used Plate (1) created, which extends over the pillar (3) on the cover glass plate (4) and whose fluctuations follow perpendicular to their plane. In the plate (1) the nosepiece (5), which is also over an eccentric pin (6) can be adjusted relative to the plate (1).

In picture 1 the revolving nosepiece is in the side view and top view shown. The function is as follows: A horizontal plate (1) is pivotable about the pivot point (2) opposite stored with the device. Near the end of the plate (1) a support (3) is attached, which is on the Cover glass plate (4) supports the film (7) and the under glass plate (8). The glass plates (4) and (3) with the film (7) can be moved together in their plane, whereby, if due to mechanical tolerances the plane is in relation to the device itself Height changes over the support (3) the plate (1) follows the new level and thus approximately the same distance between plates (1) and glass plate (4) guaranteed is.

A sleeve with a recess (10) is rotatably mounted in a block (9) and again in this sleeve (10) an axle (11) is also rotatably guided, at the end of which the pivot lever (12) is attached to one side and to which the other end of the ovjective revolver (5) was fixed.

The two objectives (13) and (14) are attached to the objective nosepiece (5) let in.

A latch (15) attached to the block (9) engages grooves (16) and (17) in the Lever (12), the angle between the grooves (16) and (17) being the angle corresponds to the same pivot point between the two lenses (13) and (14). By swiveling the lever (12), either the lens (14) (as shown) or the objective (13) is brought into congruence with the optical axis (18) of the system will.

An eccentric shaft (6) is mounted in the block (9) parallel to the lever (12) and carries the focus button (19) at its end. The eccentric pin (20) of the eccentric shaft (6) engages in a groove in the sleeve (10) and moves when the eccentric shaft (6) rotates axially upwards via the sleeve (11), objective nosepiece (5) and the swivel lever (12) or below relative to the plate (1).

To further explain the invention is the upper condenser lens (21) of the lighting system, as well as the one above the lens Deflection mirror (22).

L e r s e i t e

Claims (4)

PROTECTION CLAIMS 1.) Object iv revolver for micro-plan film readers with strong enlargements, especially d u d u n e c e n i n t that the revolver 15) is movable on a plate pivotable about point (2) (i) is attached. 2.) Objective nosepiece according to claim 1 d a d u r c h g e k e n n z e i c h -n e t that the pivoting plate (1) with its own weight over the support (3) sits vertically on the upper glass plate (4) and in its pivoting one possible vertical movement of this glass plate (4) follows. The glass plate (4) and (8) represent a film stage between which the film (7) is clamped. This film stage is movable in its own plane arranged. 3.) Objective nosepiece according to claim 1 and 2 d a d u r c h g e k e n n z e i c h -n e t that a sleeve (10) with its collar on a lever (12) or the turret (5) rests and thereby an axial movement on this Parts transfers. An eccentric pin (20) engages in a groove in the sleeve (10) Eccentric shaft (6). The axial movement takes place when this eccentric shaft is turned the sleeve (10) instead. 4.) Objective nosepiece according to claim 1 to 3 d a d u r c h g e k e n n z e i c h -n e t that a shaft (10) is coaxial and only movable radially within a sleeve (10) is mounted and at its end on the one hand the lever (12) with the Latching grooves (16) and (17), on the other hand, the objective nosepiece (5) with the objectives (13) and (14) attached.