Systems for communication in a rotary joint. In one example, a communication system includes a stator, a rotor, a plurality of optical receivers circumferentially disposed at a first radius of one of the stator and the rotor, a plurality of optical transmitters circumferentially disposed at a second radius of the other of the stator and the rotor, each optical transmitter of the plurality configured to transmit a data signal to a corresponding optical receiver of the plurality of optical receivers, and a plurality of optical elements, individual optical elements having one of a first size and a second size, wherein individual optical elements are interposed between each optical transmitter of the plurality of optical transmitters and each optical receiver of the plurality of optical receivers and arranged so as to alternate between the first size and the second size along one of the first radius and the second radius.

This invention minimizes the needed space for a changer device for optical elements which can be mounted in front or in the back or on either fork side of telescopes. It implements a design whose profile is circular and centrosymmetric and gravitanionally neutral in respect to the path of light of the surrounding optical devices as well as an optimized mechanical depth. This is achieved by moving the centrosymmetrically arranged optical elements individually into the optical path i.e. the central opening of the changing device in contrary to prior art designs wherein the optical elements are mounted on a revolving disk whose axis of rotation is not congruent with the optical axis. The invention minimizes the obstructing area and shape of the changing device as well as the gravitational stress on surrounding structures by incorporating a design with minimal space requirements.

This invention minimizes the needed space for a changer device for optical elements which can be mounted in front or in the back or on either fork side of telescopes. It implements a design whose profile is circular and centrosymmetric and gravitanionally neutral in respect to the path of light of the surrounding optical devices as well as an optimized mechanical depth. This is achieved by moving the centrosymmetrically arranged optical elements individually into the optical path i.e. the central opening of the changing device in contrary to prior art designs wherein the optical elements are mounted on a revolving disk whose axis of rotation is not congruent with the optical axis. The invention minimizes the obstructing area and shape of the changing device as well as the gravitational stress on surrounding structures by incorporating a design with minimal space requirements.

A lens module including a base, a lens, a front cover, a first shielding plate set, a second shielding plate set, and a gasket is provided. The lens is disposed on the base. The front cover is rotatably disposed above the base and the lens, and the front cover has a first through hole. Each of the first shielding plate set and the second shielding plate set is pivoted on the base. The second shielding plate set and the first shielding plate set interfere with each other. The gasket is fixed in the first through hole and coupled to the second shielding plate set. The gasket has a second through hole. When the base and the front cover rotate relative to each other, the gasket rotates with the front cover and drives the first shielding plate set and the second shielding plate set to limitedly swing.

A lens module including a base, a lens, a front cover, a first shielding plate set, a second shielding plate set, and a gasket is provided. The lens is disposed on the base. The front cover is rotatably disposed above the base and the lens, and the front cover has a first through hole. Each of the first shielding plate set and the second shielding plate set is pivoted on the base. The second shielding plate set and the first shielding plate set interfere with each other. The gasket is fixed in the first through hole and coupled to the second shielding plate set. The gasket has a second through hole. When the base and the front cover rotate relative to each other, the gasket rotates with the front cover and drives the first shielding plate set and the second shielding plate set to limitedly swing.

A projection lens is separated by a second mirror into a first optical system that is disposed so as to be closer to an image forming panel and a second optical system that includes the second mirror and is disposed so as to be closer to a screen which is a projection surface. The second optical system is held rotatably around a second optical axis with respect to the first optical system by a first rotation mechanism. A rotation angle of the second optical system with respect to the first optical system is detected by a first sensor. A tilt angle of the projected image on the projection surface by the rotation angle is obtained by a tilt correction section, and the display position of the image to be displayed on the image forming panel is corrected according to the tilt angle.

A periscope includes an object window 4, a first reflector 5, a second reflector 6; and an intermediate port between the first reflector 5 and the second reflector 6. The first reflector 5 is arranged to reflect light from the object window 4 towards the second reflector 6 through the intermediate port. The second reflector 6 is selectively movable between a first position of use in which the second reflector 6 reflects light from the first reflector 5 towards a viewing position and a second position of use in which the second reflector 6 closes the intermediate port.

A periscope includes an object window 4, a first reflector 5, a second reflector 6; and an intermediate port between the first reflector 5 and the second reflector 6. The first reflector 5 is arranged to reflect light from the object window 4 towards the second reflector 6 through the intermediate port. The second reflector 6 is selectively movable between a first position of use in which the second reflector 6 reflects light from the first reflector 5 towards a viewing position and a second position of use in which the second reflector 6 closes the intermediate port.

Systems for communication in a rotary joint. In one example, a communication system includes a stator, a rotor, a plurality of optical receivers circumferentially disposed at a first radius of one of the stator and the rotor, a plurality of optical transmitters circumferentially disposed at a second radius of the other of the stator and the rotor, each optical transmitter of the plurality configured to transmit a data signal to a corresponding optical receiver of the plurality of optical receivers, and a plurality of optical elements, individual optical elements having one of a first size and a second size, wherein individual optical elements are interposed between each optical transmitter of the plurality of optical transmitters and each optical receiver of the plurality of optical receivers and arranged so as to alternate between the first size and the second size along one of the first radius and the second radius.

Systems for communication in a rotary joint. In one example, a communication system includes a stator, a rotor, a plurality of optical receivers circumferentially disposed at a first radius of one of the stator and the rotor, a plurality of optical transmitters circumferentially disposed at a second radius of the other of the stator and the rotor, each optical transmitter of the plurality configured to transmit a data signal to a corresponding optical receiver of the plurality of optical receivers, and a plurality of optical elements, individual optical elements having one of a first size and a second size, wherein individual optical elements are interposed between each optical transmitter of the plurality of optical transmitters and each optical receiver of the plurality of optical receivers and arranged so as to alternate between the first size and the second size along one of the first radius and the second radius.