Optical instrument having spring-loaded sealing element at one or both sides of an end window

1. An optical instrument, in particular an endoscope, with a hollow instrument housing for receiving optical elements, wherein a distal end and/or proximal end of the hollow instrument housing is closed in a fluid-tight manner via an end window,

wherein each end window is sealed off in a fluid-tight manner with respect to the instrument housing via at least one sealing element wherein the at least one sealing element is spring-loaded via at least one spring element in a direction of the respective end window in such a way, that the respective end window is pressed in a sealing manner against the instrument housing, and wherein the at least one spring element is configured as an independent structural part which is fixable inside the optical instrument; and

wherein at least one spring-loaded sealing element is arranged upstream and downstream of each end window in an axial direction of the instrument housing.

2. The optical instrument of claim 1 , wherein each spring-loaded sealing element is spring-loaded in the direction of the respective end window via the at least one spring element.

3. The optical instrument of claim 2 , wherein each spring element bears directly on the associated sealing element.

4. The optical instrument of claim 2 , wherein each spring element acts on the associated sealing element via at least one pressure element.

5. The optical instrument of claim 1 , wherein each spring-loaded sealing element is designed as an O-ring.

6. The optical instrument of claim 2 , wherein each spring element is designed as a spring disk or a spring sleeve.

7. The optical instrument of claim 6 , wherein each spring element is designed as a spring disk, and the spring disks are mounted at one end in a radially surrounding groove.

8. The optical instrument of claim 4 , wherein each pressure element is designed as a pressure sleeve.

9. The optical instrument of claim 1 , wherein the spring-loaded sealing elements on both sides of each end window are each spring-loaded in the direction of the respective end window via the at least one spring element.

10. The optical instrument of claim 2 , wherein the at least one spring-loaded sealing element is designed as a U-shaped seal arranged on a shoulder of the instrument housing, wherein the at least one spring element is designed as a V-shaped spring, which is arranged between the legs of the U-shaped seal.

11. The optical instrument of claim 1 , wherein each end window is designed as a cover glass and/or end lens.

12. An optical instrument, in particular an endoscope, with a hollow instrument housing for receiving optical elements, wherein an end of the hollow instrument housing is closed in a fluid-tight manner via an end window,

wherein the end window is pressed in a sealing manner against the instrument housing via at least one sealing element wherein the at least one sealing element is spring-loaded and bears directly on the end window via a spring element in a direction of the respective end window, and wherein the spring element is configured as an independent structural part which is fixable inside the optical instrument; and

wherein each spring element bears directly on the associated sealing element.

13. The optical instrument of claim 12 , wherein each spring element acts on the associated sealing element via at least one pressure element.

14. An optical instrument, in particular an endoscope, with a hollow instrument housing for receiving optical elements, wherein an end of the hollow instrument housing is closed in a fluid-tight manner via an end window;

wherein the end window includes a first side and a second side, with at least one sealing element bearing directly on each of the first side and the second side of the end window;

wherein the at least one sealing element on the first side of the end window is spring-loaded via a spring element in a direction of the respective end window in such a way, that the respective end window is pressed in a sealing manner against the instrument housing, and wherein the spring element is configured as an independent structural part which is fixable inside the optical instrument; and

wherein each spring element bears directly on the associated sealing element.

15. The optical instrument of claim 14 , wherein the at least one sealing element on the second side of the end window is spring-loaded via the spring element in the direction of the respective end window.

16. The optical instrument of claim 14 , wherein each spring element is designed as a spring disk or a spring sleeve.

17. The optical instrument of claim 14 , wherein each spring element is a cylindrical coil.