ARRANGEMENT FOR THE CHANGE OF THE FOCUS OF AN OPTICAL SYSTEM

The invention concerns an arrangement for the change of the Breunpunktes of an optical system along a Hauptmeri i LV while maintaining the focus along in addition the senkrechten the Hauptmeridians with two toward the Z-axis of the system unverschiebbaren Zylinderlinse and a Zylinderlinse adjustable between these lenses arranged toward the optics “chen axle. The US-PS Nr.3, 669.530 describes an arrangement for the change of the cylindrical Brechkraft in a Optometer, whereby for the change of the Brechkraft two Zylinderlinsen are present. This arrangement requires however at least two separated movable segments, i.e. two Zylinderlinsen or a Zyliuderllnse and a target. The US-PS Nr.3, 664.631 describes a Optometer with several Zylinderlinsen, which are adjustable along the Z-axis. In the Fig.2, which is regarded as the most interesting, the middle Zylinderlinse of a system with three ZylinderHnsen is independently innerhMb the adjustable system movable. Now during the initially mentioned arrangement it is suggested according to invention that the cylinder axle of the adjustable Zylinderlinse stands on the cylinder axles of the unverschiebbaren Zylinderlinsen perpendicularly, which are combined Brechkraft of the two unverschiebbaren Zylinderlinsen for instance equal to the Brechkraft the adjustable Zylinderlinse and that the system on a Böhmen, formed by the three Zylinderlinsen, is stored, which is swivelling around the Z-axis of the system. The invention ird now on the basis the designs more near described. Fig.1 is a side view of a preferential execution form of the invention, partly on average, Fig.2 is a plan view on a cut along the line ii-ll the Fig.1, Fig.3 is a diagram of the information signal, which is produced by a Wandier in the arrangement, Fig.4 is a side view of a second execution form in the cut and Fig.5 is partly a side view of this second execution form. In accordance with Fig.1 the arrangement has a framework with a lower frame part --1-- and an upper frame part --2--. The upper frame part --2-- carries an outside race --4-- and ball bearings --5-- carry over an internal race --7-- swivelling an upper lens mounting plate --6--. The lower frame part --1-- carries an outside race --8-- and ball bearings --9-- carry in cooperation with the outside race --8-- over an internal race --11-- a lower lens mounting plate --10--. The “upper lens mounting plate --6-- and the lower lens mounting plate --10-- are by bars --12-- connected, in order to specify a firm distance and to connect the lens mounting plates for simultaneous twist. By camps --14-- is a carriage --13-- verse blowable on the bars --12-- arranged. The Yätnehmer --16-- a cheek --15-- is workmoderate with a screw pillar --17-- in interference. The screw pillar --17-- becomes by an engine --18-- into one of the two directions rotates, so that the carriage --13-- alternatively along the bars --12-- one moves. An engine --19-- rotated over a belt --20-- and a wheel --21-- the optical arrangement, in order to stop the situation of the Hauptmeridiane so alternatively. The descriptive arrangement carries two Zylinderlinsen --28, 29--, which exhibit a combined Brechkraft in one main level. The cylindrical Brechkraft of the Zylinderlinse --30-- is equal the combined cylindrical Brechkraft of the lenses --28, 29-- in a Hauptmeridian nodal to the Hauptmeridian of the lenses --28, 29--. The focus in the Hauptmeridian of the Zylinderlinse --30-- becomes by movement of the Schät ens --13-- along the waves --12. - changed. The reference situation --22-- that situation of the Zyllnderlinse shows --30--, with which the focus is alike in both Hauptmeridianen. Moves the Zy] iuderlinse --30-- from this reference situation --22--, then the focus is continuously changed along the Hauptmeridians. It is often desired to lead back an element into both directions along a course into a reference situation. In the Fig.l is the reference situation --22-- a selected situation, into which one the lens --30-- frequently to lead back wants. With the cheek --15-- is a cover plate --23-- connected, those into a groove --27-- the carriage --13-- intervenes. The Ahdeckblende --23-- extends parallel to the direction of motion of the carriage --13-- along the bars --12--. A source of light, e.g. an IR transmitter --25--, is on a carrier --26-- planned, that the movement of the Ahdeckblende --23-- neighbouring is. The carrier --26-- arranges on the opposite side of the movement close course of the cover plate --23-- a Wandier --24-- on. Of the IR transmitter --25-- delivered jet becomes by the cover plate --23-- blocked, if itself the Zylinderlinse --30-- above the reference situation --22--finds. Is Nr.352435 the Zylinderlinse --30-- below the reference situation --22--, then produces for the wall! it --24-- a signal, which is caused by the unhindered light-beam bundle. Fig.3 shows a diagram by the wall! it --24-- produced signal as a function of the situation of the Zylinderlinse --30--. Is the Zylinderlinse --30-- above the reference situation --22-- and the control becomes --31-- operated, around the Zylinderlinse --30-- into the reference situation to lead back, then the control arranges that the engine --18-- see the counterclockwise twistedly, there the light-beam bundle by the cover plate --23-- is blocked, to the Wand/er --24-- Light of the light queue --25-- receives. The borrowing change arranges then in the control --31--that the engine --18-- one continues. Is the Zylinderlinse --30-- below the reference situation --22-- and the control becomes --31-- operated, around the Zylinderlinse --30-- into the reference situation to lead back, then the presence of a signal of the Wand/er causes --24-- in the control --31--that the engine --18-- .im clockwise direction turns, whereby the Zylinderllnse --30-- against the reference situation --22-- one moves. As soon as the borrowing luminous beam by the cover plate --23-- , holds the control is interrupted --31-- the engine --18-- on. A manipulation of the control --31-- the Zylinderlinse brings --30-- of each situation of the t5 of carriage --13-- along that blowing --12-- into the reference situation --22-- back. In accordance with the Fig.4 and 5 has the lower frame part --101-- an outside race --108--, that over a ball bearing --109-- an optical arrangement --103-- carries, which a lower cylinder mounting plate --110-- by means of a surface serving as internal race --111-- holds. The upper Rahmenteü --102-- the opposite end of the optical arrangement carries --103-- by means of an outside race --104-- in the cooperation with a ball bearing --i05-- and the upper lens mounting plate --106-- becomes from a surface working as internal race --107-- held. The upper lens mounting plate --106-- is with the lower lens mounting plate --110-- by a cylinder --112-- connected, between the lens mounting plates and a simultaneous twist maintains an even distance effectuation. A carriage --113-- is in the cylinder --112-- adjustably arranged. A cheek --115-- is with a ring --ll4-- in interference, that over slots --120-- with the carriage --113-- is connected. Becomes the optical arrangement --103-- rotated, then the groove steps --119-- in the ring --114-- with the tap --116-- in interference, whereby the carriage --113-- in the cylinder --112-- one shifts, if the cheek --115-- by the Sehraubspindel --117-- one moves. The screw jack --117-- becomes by the engine --118-- into one of the two directions rotates.