Projector

• US 20090027628A1
• Filed: 07/23/2008
• Published: 01/29/2009
• Est. Priority Date: 07/24/2007
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: Okamoto, Tomoyuki, Hosoi, Yoshito, HOSHINO, Hidetaka
• Granted Patent: US 7,959,304 B2
• Time in Patent Office: Days
• US Class Current: 353/70
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066

Abstract

An image by means of a projection light is projected without any distortion both onto a surface approximately parallel to an installation surface, and onto a surface approximately perpendicular to the installation surface.

In a case in which reflecting surfaces are held in a horizontal condition, and a reflecting surface of a reflecting mirror on which a projection light falls is formed into a planar surface, individual light rays fall on positions on a table surface. As these positions are evenly spaced, an image projected onto the table surface becomes a non-distorted image. On the other hand, in a case in which the surfaces are held in an inclined condition, and a surface on which the projection light falls is formed into a curved surface, individual light rays caused to emerge from a light modulation device at even intervals fall on a wall surface. Incidence positions of the individual light rays being evenly spaced, an image projected onto the wall surface becomes the non-distorted image.

Claims

1. A projector which projects an image by means of a projection light onto a surface approximately parallel, or a surface approximately perpendicular, to an installation surface, comprising:

a first reflecting surface which reflects the projection light toward the approximately parallel surface;

a second reflecting surface which reflects the projection light toward the approximately perpendicular surface; and

a reflecting surface switching section which can switchably place the first reflecting surface and the second reflecting surface in an optical path of the projection light.

2. The projector according to claim 1, wherein

shapes of the first reflecting surface and the second reflecting surface are different.

3. The projector according to claim 1, wherein

at least one of the first reflecting surface and the second reflecting surface is an aspherical surface or a free-form surface.

4. The projector according to claim 1, wherein

one of the first reflecting surface and the second reflecting surface is a planar surface.

5. The projector according to claim 1, further comprising:

an image inversion section which inverts the image by means of the projection light by switching between a case of placing the first reflecting surface in the optical path of the projection light and a case of placing the second reflecting surface in the optical path of the projection light.

6. The projector according to claim 1, wherein

the reflecting surface switching section has a reflecting mirror, having the first reflecting surface and the second reflecting surface, removably attached thereto.

7. The projector according to claim 1, further comprising:

a protective section which protects a reflection surface, among the first reflecting surface and the second reflecting surface, which is not placed in the optical path of the projection light.

8. The projector according to claim 1, wherein

the second reflecting surface is formed on the other side of the first reflecting surface, and the reflecting surface switching section is attached in such a way as to rotatably switch between the first reflecting surface and the second reflecting surface.