A projection lens includes a lens barrel that accommodates an optical system from which light incident from the housing exits, and that has a first rotary tube that rotates around an optical axis and a first fixed tube at which the first rotary tube is rotatably mounted; and a first conduction portion for performing electrical conduction, the first conduction portion having a fixed electrode that is provided at the first fixed tube and a rotary electrode that is provided at the first rotary tube and that rotates as a result of rotating the first rotary tube, the rotary electrode being disposed at a position that faces the fixed electrode and contacting the fixed electrode at least at a rotation position that has been preset.

A projection lens includes a lens barrel that accommodates an optical system from which light incident from the housing exits, and that has a first rotary tube that rotates around an optical axis and a first fixed tube at which the first rotary tube is rotatably mounted; and a first conduction portion for performing electrical conduction, the first conduction portion having a fixed electrode that is provided at the first fixed tube and a rotary electrode that is provided at the first rotary tube and that rotates as a result of rotating the first rotary tube, the rotary electrode being disposed at a position that faces the fixed electrode and contacting the fixed electrode at least at a rotation position that has been preset.

An image projection device is disclosed having a body defining an aperture that includes a slide frame receiving slot that is transverse to the aperture and a magnifying lens positioned in alignment with the aperture at the front of the body. The image projection device can be attached to a mobile device and uses the camera flash of the mobile device to provide the light source to illuminate a slide transparency. The mobile device can identify a particular slide transparency through information encoded on the slide frame in order to coordinate audio or video output with the projected slide.

An image projection device is disclosed having a body defining an aperture that includes a slide frame receiving slot that is transverse to the aperture and a magnifying lens positioned in alignment with the aperture at the front of the body. The image projection device can be attached to a mobile device and uses the camera flash of the mobile device to provide the light source to illuminate a slide transparency. The mobile device can identify a particular slide transparency through information encoded on the slide frame in order to coordinate audio or video output with the projected slide.

A kit for creating a flat folding projection device is provided and includes a lens and a sheet defining at least a first, second, third and fourth panels, each panel separated from the other panels by at least one fold. A hole is positioned in the first panel, the hole defining an edge. A cut is positioned in the first panel adjacent to the hole such that the first panel on either side of the cut can be separated to create a space configured to receive and hold the lens therein. Further includes is one of: a light source, a translucent sheet or a light source and a translucent sheet. An envelope contains the foregoing such that a thickness of the envelope is less than inches.

A kit for creating a flat folding projection device is provided and includes a lens and a sheet defining at least a first, second, third and fourth panels, each panel separated from the other panels by at least one fold. A hole is positioned in the first panel, the hole defining an edge. A cut is positioned in the first panel adjacent to the hole such that the first panel on either side of the cut can be separated to create a space configured to receive and hold the lens therein. Further includes is one of: a light source, a translucent sheet or a light source and a translucent sheet. An envelope contains the foregoing such that a thickness of the envelope is less than inches.

Disclosed is a projector (1), comprising a projector body (10) with a lens (12), and a light reflection assembly (20) for adjusting a projecting direction of the lens (12). The light reflection assembly (20) comprises a reflective mirror (23), and the light reflection assembly (20) is provided to be rotatably connected with the projector body (10). During the rotation, a mirror face of the reflective mirror (23) always faces towards the lens (12), so that the reflective mirror (23) adjusts the angle of the projecting direction between the mirror face and the lens (12) with the rotation of the light reflection assembly (20), so as to adjust the projecting location of the lens (12) by means of the rotation of the reflective mirror (23), such that the projecting direction can be changed without moving the projector (1).

Disclosed is a projector (1), comprising a projector body (10) with a lens (12), and a light reflection assembly (20) for adjusting a projecting direction of the lens (12). The light reflection assembly (20) comprises a reflective mirror (23), and the light reflection assembly (20) is provided to be rotatably connected with the projector body (10). During the rotation, a mirror face of the reflective mirror (23) always faces towards the lens (12), so that the reflective mirror (23) adjusts the angle of the projecting direction between the mirror face and the lens (12) with the rotation of the light reflection assembly (20), so as to adjust the projecting location of the lens (12) by means of the rotation of the reflective mirror (23), such that the projecting direction can be changed without moving the projector (1).

A portable display screen that can be broken down into components for easy transport and storage, while also being relatively easy to assemble into a self-supporting display screen with a flat surface without distracting wrinkles or other defects.

A portable display screen that can be broken down into components for easy transport and storage, while also being relatively easy to assemble into a self-supporting display screen with a flat surface without distracting wrinkles or other defects.