Vehicular lamp

• US 7,775,697 B2
• Filed: 03/09/2009
• Issued: 08/17/2010
• Est. Priority Date: 03/10/2008
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Hirano, Junichi, Natsume, Kazunori
• Primary Examiner(s): Choi; Jacob Y
• Application Number:
  US12/400,466
• Publication Number:
  US 20090225562A1
• Time in Patent Office: 526 Days
• Field of Search: 362/551, 362/556, 362/555, 362/554, 362/540, 362/541, 362/542, 362/544, 362/509, 362/498, 362/499, 362/511
• US Class Current: 362/511
• CPC Class Codes: F21S 43/239 plate-shaped
• CPC Class Codes: F21S 43/245 emitting light from one or more of its major surfaces
• CPC Class Codes: F21S 43/249 with two or more light sources being coupled into the light guide
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide

Abstract

A vehicular lamp includes a light source positioned inside a lamp chamber. The lamp chamber is formed from a lamp body fixed to a vehicle body and a front cover that covers a front open portion thereof. The vehicular lamp includes a light guide that includes a side end surface to which light emitted from the light source is incident on one side thereof; a light-emitting surface that emits the light that is incident from the side end surface in a predetermined direction; and a reflective back surface that has a reflecting portion that faces the light-emitting surface. The light guide made from translucent material that is positioned on one side inside the light chamber following along with the shape of the lamp front cover. A plurality of stippling steps that have a generally conical shape are provided on the reflective back surface of the light guide. A central axis that passes through an apex angle of every stippling step slants toward the predetermined emission direction of the light with respect to a virtual vertical line perpendicular to the reflective back surface.

Claims

1. A vehicular lamp comprising:

a lamp body having an open portion;

a lamp front cover that covers the open portion so as to form a lamp chamber;

a light source disposed inside the lamp chamber;

a light guide disposed inside the lamp chamber and positioned on one side inside the lamp chamber following along with a shape of the lamp front cover,

the light guide comprising;

a side end surface to which light emitted from the light source is incident on one side thereof;

a light-emitting surface that emits the light that is incident from the side end surface in a predetermined direction;

a reflective back surface comprising a reflecting portion facing the light-emitting surface; and

a plurality of stippling steps having a generally conical shape disposed on the reflective back surface,

wherein a central axis that passes through an apex angle of every stippling step slants toward the predetermined emission direction of the light with respect to a virtual vertical line perpendicular to the reflective back surface.

2. The vehicular lamp according to claim 1,

wherein an introduction width of the light guide, which introduces the emitted light that is incident from the side end surface, is set to 90% or more of a thickness dimension of the light guide,

wherein the thickness dimension of the light guide is a distance between the light-emitting surface and the reflective back surface, minus height dimensions of the stippling steps.

3. The vehicular lamp according to claim 1, wherein the light guide has a tapered shape such that a distance between the light-emitting surface and the reflective back surface becomes gradually more narrow from the side end surface on the light source side toward the other end side.

4. The vehicular lamp according to claim 1, wherein placement density of the stippling steps increases in proportion to a distance from the side end surface.

5. The vehicular lamp according to claim 2, wherein the light guide has a tapered shape such that a distance between the light-emitting surface and the reflective back surface becomes gradually more narrow from the side end surface on the light source side toward the other end side.

6. The vehicular lamp according to claim 2, wherein placement density of the stippling steps increases in proportion to a distance from the side end surface.

7. The vehicular lamp according to claim 3, wherein placement density of the stippling steps increases in proportion to a distance from the side end surface.

8. A vehicular lamp comprising:

a light source positioned inside a lamp chamber,

wherein the lamp chamber is formed from;

a lamp body fixed to a vehicle body, and

a front cover that covers a front open portion thereof;

a light guide that includes a side end surface to which light emitted from the light source is incident on one side thereof;

a light-emitting surface that emits the light that is incident from the side end surface in a predetermined direction; and

a reflective back surface that has a reflecting portion that faces the light-emitting surface,

wherein the light guide is made from translucent material,

wherein the light guide is positioned on one side inside the lamp chamber following along with a shape of the lamp front cover,

wherein a plurality of stippling steps that have a generally conical shape are provided on the reflective back surface of the light guide, and

wherein a central axis that passes through an apex angle of every stippling step slants toward the predetermined emission direction of the light with respect to a virtual vertical line perpendicular to the reflective back surface.

9. The vehicular lamp according to claim 8,

wherein an introduction width of the light guide, which introduces the emitted light that is incident from the side end surface, is set to 90% or more of a thickness dimension of the light guide,

wherein the thickness dimension of the light guide is a distance between the light-emitting surface and the reflective back surface, minus height dimensions of the stippling steps.

10. The vehicular lamp according to claim 8, wherein the light guide has a tapered shape such that a distance between the light-emitting surface and the reflective back surface becomes gradually more narrow from the side end surface on the light source side toward the other end side.

11. The vehicular lamp according to claim 8, wherein placement density of the stippling steps increases in proportion to a distance from the side end surface.

12. The vehicular lamp according to claim 9, wherein the light guide has a tapered shape such that a distance between the light-emitting surface and the reflective back surface becomes gradually more narrow from the side end surface on the light source side toward the other end side.

13. The vehicular lamp according to claim 9, wherein placement density of the stippling steps increases in proportion to a distance from the side end surface.

14. The vehicular lamp according to claim 10, wherein placement density of the stippling steps increases in proportion to a distance from the side end surface.