Illuminating apparatus

• US 20030147244A1
• Filed: 01/30/2003
• Published: 08/07/2003
• Est. Priority Date: 02/05/2002
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tenmyo, Yoshiharu
• Granted Patent: US 6,974,236 B2
• Time in Patent Office: Days
• US Class Current: 362/339
• CPC Class Codes: F21V 5/045 the lens having discontinuous faces, e.g. Fresnel lenses
• CPC Class Codes: F21V 7/0091 using total internal reflection

Abstract

This specification discloses an illuminating apparatus having a light source and an optical unit disposed forwardly on the object side of the light source, the optical unit being provided with an incidence surface on which light from the light source is incident, a light emergence surface provided with a Fresnel lens, and a side reflecting surface for totally reflecting the light incident on the incidence surface toward the Fresnel lens, wherein the light totally reflected by the side reflecting surface is refracted by the Fresnel lens and efficiently irradiates the object.

Claims

1. An illuminating apparatus comprising:

a light source; and

an optical unit disposed forwardly on the object side of the light source;

the optical unit being provided with an incidence surface on which light from the light source is incident, a light emergence surface provided with a Fresnel lens, and a side reflecting surface for totally reflecting the light incident on the incidence surface toward the Fresnel lens;

wherein the light totally reflected by the side reflecting surface is refracted by the Fresnel lens and emerges toward the object side thereof.

2. An illuminating apparatus according to claim 1, wherein the angle formed between an edge surface of the Fresnel lens which is near to the optical axis of the optical unit and that optical axis is greater away from the optical axis.

3. An illuminating apparatus according to claim 1, further comprising a reflecting member disposed on a side of the light source which is opposed to the optical unit for reflecting the light from the light source to the optical unit side.

4. An illuminating apparatus according to claim 1, wherein the light source is a light emitting tube, and the vertical angle of the Fresnel lens is formed along a direction perpendicular to the lengthwise direction of the light emitting tube.

5. An illuminating apparatus comprising:

a light source;

an optical unit disposed forwardly on the object side of the light source;

the optical unit being provided with an incidence surface on which light from the light source is incident, a reflecting surface for totally reflecting some of the light incident from the incidence surface, and a light emergence surface; and

a reflecting member disposed on a side of the light source which is opposed to the optical unit for reflecting the light from the light source to the optical unit side;

wherein the inclination of a tangent on the reflecting surface on the light emergence surface side of the optical unit with respect to the optical axis of the optical member or the inclination of a tangent on the reflecting member on the incidence surface side with respect to the optical axis of the optical member gradually increases toward the direction of travel of the light.

6. An illuminating apparatus comprising:

a light source;

an optical unit disposed forwardly on the object side of the light source;

the optical unit being provided with an incidence surface on which light from the light source is incident, a reflecting surface for totally reflecting some of the light incident from the incidence surface, and a light emergence surface; and

a reflecting member disposed on a side of the light source which is opposed to the optical unit for reflecting the light from the light source to the optical unit side;

wherein the opening diameter of the reflecting member on the incidence surface side gradually increases toward the direction of travel of the light.

7. An illuminating apparatus comprising:

a light source; and

an optical unit disposed forwardly on the object side of the light source;

the optical unit being provided with an incidence surface on which light from the light source is incident, a reflecting surface for totally reflecting some of the light incident from the incidence surface, and a light emergence surface;

wherein a diffusing portion is formed on at least a portion of the reflecting surface.