Focal length extender for telescopic imaging systems

Abstract

The invention describes a focal length extender for a telescopic imaging system with interchangeable viewing eyepieces, including a cylindrical housing, which has a first and a second stop plane which are perpendicular to its cylinder axis in the direction of the light with associated connecting elements to the telescope body and for interchangeable viewing eyepieces and in which the housing has a relay lens arranged between the first stop plane and the second stop plane, wherein the relay lens is divided in two and consists of a first positive, neutral or negative lens element and a further negative lens element, wherein between the first and the further lens element, a beam splitter surface is arranged downstream at an angle to the optical axis of the imaging system and the first and further lens element together with the distance therebetween has an overall negative refractive power.

Claims

1. A focal length extender for a telescopic imaging system with interchangeable viewing eyepieces, the focal length extender comprising: a cylindrical housing, which has a first and a second stop plane, the first and the second stop plane being perpendicular to an axis of the cylindrical housing in the direction of a light, with associated connecting elements to a telescope body and to interchangeable viewing eyepieces; and two relay lenses arranged between the first stop plane and the second stop plane, wherein the two relay lenses consist of a first positive, neutral or negative lens element and a further negative lens element, the two lens elements being positioned on a same axis, between the first and the further lens elements, a beam splitter surface is arranged downstream at an angle to an optical axis of the imaging system, the first and the further lens elements together with the distance therebetween have an overall negative refractive power, the two relay lenses being immovable relative to the cylindrical housing, and the focal length extender obtaining the same imaging characteristics for the interchangeable viewing eyepieces.

2. The extender according to claim 1, wherein the front- and rear-side beam splitter surface in the direction of light is connected to a beam splitter element with optically transparent prisms with light entry and light exit surfaces standing perpendicular to the optical axis.

3. The extender according to claim 1, wherein the beam splitter surface has a freely formed curvature.

4. The extender according to claim 1, wherein optical deflection and/or imaging elements with an electric imaging sensor with a processor in their imaging plane are arranged in the light beam which is reflected from the beam splitter surface after entry into the extender and which emerges from the beam splitter element.

5. The extender according to claim 4, wherein the optical deflection and/or imaging elements and the imaging sensor with processor are arranged within the housing.

6. The extender according to claim 4, wherein the processor is connected with a data transmission interface.

7. The extender according to claim 6, further comprising a display configured to illustrate the image recorded from the imaging sensor, wherein the display is arranged inside or outside the housing, and the display is controllable via the interface.

8. The extender according to claim 7, wherein a screen within the housing can be observed via the rear-side beam splitter surface.

9. The extender according to claim 7, wherein external communication data can be displayed via the interface on the display arranged within the housing.

10. The extender according to claim 1, wherein the housing of the extender or an intermediary lens barrel of the extender containing the beam splitter, the imaging optic and the imaging sensor is arranged in a manner which is rotatable about the optical axis of the two relay lenses with respect to an eyepiece view.

11. The extender according to claim 1, wherein the viewing eyepiece contains a prism or lens inversion system.

12. The extender according to claim 1, wherein the telescopic imaging system is a photo lens.

13. The extender according to claim 1, wherein the two lens elements are fixedly mounted with a beam splitter interposed therebetween.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the extender optic for a photo lens, and

(2) FIG. 2 shows the extender optic for a telescope lens.

DETAILED DESCRIPTION OF THE DRAWINGS

(3) The extender optic illustrated in FIG. 1 shows the optical axis 1 of an imaging beam path coming from a photo lens, not shown, and extending to an eyepiece module, also not shown. The image beams are partially reflected by a beam splitter surface 2 arranged at an angle to the optical axis 1. The beam splitter surface 2 is inserted in a prism system constructed from two prisms 3, 4. The prism surface 5 is mirrored and directs the decoupled imaging beams 6 via the imaging lenses 7 to a camera sensor 8.

(4) On the light entry side, a first lens element 9 of the relay lens is attached to the prism 3. On the light exit side, a further lens element 10 of the relay lens is placed on the prism 4. Both lens elements 9, 10 together have a negative refractive power.

(5) In the exemplary embodiment shown in FIG. 2, which is suitable for a telescope lens, parts identical to those in FIG. 1 are provided with the same reference characters. Here, the first lens element 11 of the relay lens arranged on the light entry side has a positive refractive power. The further lens element 10 in turn has a negative refractive power.

(6) The housing which encloses the extender optic and its stop surfaces are not shown. The design must be adapted to the existing photo lens or telescope lens and operated by an experienced engineer in accordance with his expertise in the art. This also applies to the arrangement of suitable image processors, interfaces and displays.

(7) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

LIST OF REFERENCE CHARACTERS

(8) 1 optical axis 2 beam splitter surface 3, 4 prisms 5 mirrored prism surface 6 decoupled imaging beam 7 imaging lenses 8 camera sensor 9; 11 first lens element relay lens 10 further lens element relay lens