JP2006294380A - Projector-type head lamp for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector-type head lamp in which illumination light efficiency is improved by increasing a quantity of light nearby a cut line of a light distribution pattern. <P>SOLUTION: In the projector-type head lamp 10 for an automobile, a shade 17 having a top face part 17a is provided in a lighting fixture between a bulb 11 and a projection lens 12, a flat face is formed on the top face part 17a to face an optical axis O connecting the bulb 11 with the projection lens 12, and a light reflection treated film is formed on the flat face on the side nearer to the bulb 11 rather than the position of the focus F1 of the projection lens 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement in a projector-type headlamp for an automobile that shields a light beam that is unnecessary in terms of light distribution characteristics with a shade.

  2. Description of the Related Art Conventionally, a projector type headlamp for an automobile is known in which a shade (light shielding plate) 3 is provided in a lamp between a bulb 1 and a projection lens (convex lens) 2 as shown in FIG. It has been.

  This type of shade 3 has a top surface portion 4 which is a flat surface, and a light reflection treatment film 5 is formed on the top surface portion 4. The light beam P emitted from the bulb 1, reflected by the elliptical mirror reflecting surface 6 and traveling downward is reflected by the light reflection processing film 5 and converted into an upward light beam.

According to this type of projector-type headlamp for an automobile, the visibility of a road sign existing at a position higher than the height position of the projector-type headlamp can be improved (for example, see Patent Document 1).
Japanese Utility Model Publication No. 05-66806

  However, in this type of conventional projector-type headlamp for an automobile, the light reflection processing film 5 is provided including the focal position F of the projection lens 2, so that it is closer to the projection lens 2 than the focal position F. The light flux P reflected by the light reflection processing film portion 5a spreads outside the cut line of the light distribution pattern, causing glare and hindering improvement in illumination efficiency. In FIG. 1, reference numeral 5b denotes a light reflection processing film portion closer to the bulb 1 than the focal length F.

  The present invention has been made in view of the above circumstances, and its object is to increase the amount of illumination light in the vicinity of the cut line of the light distribution pattern, and thus for an automobile that can be expected to improve the illumination light rate. It is to provide a projector type headlamp.

  According to a first aspect of the present invention, there is provided a projector-type headlamp for an automobile, wherein a lamp having a top surface portion is provided in a lamp between the bulb and the projection lens, and the bulb and the projection lens are provided on the top surface portion. In the projector-type headlamp in which a flat surface facing the optical axis to be connected is formed, a light reflection processing film is formed on the flat surface closer to the bulb than the focal position of the projection lens. To do.

  According to a second aspect of the present invention, there is provided a projector-type headlamp for an automobile according to a second aspect of the present invention, wherein the shade is rotatable so as to switch a light distribution characteristic between a low beam and a high beam. An inclined surface facing the lens and inclined downward from the flat surface is formed, and a light reflection treatment film is formed on the inclined surface.

  According to a third aspect of the present invention, there is provided an automotive projector-type headlamp having an inclination angle with respect to the flat surface larger than a straight line connecting a lower end of the projection lens and the focal point.

  According to the projector type headlamp for an automobile according to claim 1, since the light reflection processing film is provided on the bulb side with respect to the focal point of the projection lens, the light is emitted from the bulb and reflected by the reflecting surface of the ellipsoidal mirror or the like. Thus, the downward light beam can be converted into an upward light beam and concentrated near the cut line of the light distribution pattern, and an improvement in the illumination light rate can be expected.

  According to the projector-type headlamp for an automobile according to claim 2, since the low beam and the high beam can be switched, the light quantity at the time of the high beam can be increased.

  According to the projector-type headlamp for an automobile according to claim 3, the light beam reflected by the ellipsoidal mirror reflecting surface or the like and directed downward from the lower end of the projection lens at the time of the low beam can be reflected at the time of the high beam and converted into the upward light beam. Thus, effective use of the illumination light beam can be achieved.

  Embodiments of a projector type headlamp according to the present invention will be described below with reference to the drawings.

(Example 1)
FIG. 2 is a cross-sectional view of a projector-type headlamp 10 according to the present invention. The projector-type headlamp 10 is provided with a bulb 11 and a projection lens 12 spaced apart in the direction in which the optical axis O extends. A shade (light shielding plate) 13 is provided in the lamp of the headlamp 10. The bulb 11 is attached to the housing 14, the inner surface of the housing 14 is an ellipsoidal mirror reflecting surface 15, and a reference numeral 11 a is a light emitting portion of the bulb 11.

  Here, the shade 13 is composed of a pair of plate bodies 16 and 17 provided at intervals in the direction in which the optical axis O extends. Flat surfaces 16a and 17a of the plates 16 and 17 are formed with flat surfaces facing the optical axis O connecting the bulb 11 and the projection lens 12 as shown in an enlarged view in FIG.

  The top surface portion 16a is provided on the projection lens 12 side with respect to the focal point F1 of the projection lens 12, and the top surface portion 17a is provided on the bulb 11 side with respect to the focal point F1 of the projection lens 12. A low reflection treatment film is formed on the top surface portion 16a by black coating, and a high reflection treatment film as a light reflection treatment film is formed on the top surface portion 17a by an aluminum vapor deposition treatment.

  Since there is no light reflection processing film at the focal point F1 of the projection lens 12, the degree of freedom of the assembling is guaranteed when the shade 13 is assembled into the lamp.

  According to the projector type headlamp 10, since the high reflection processing film exists behind the focal point F 1 of the projection lens 12, the light flux P 1 emitted from the light emitting portion 11 a of the bulb 11 and directed downward by the elliptic mirror reflecting surface 15. Is reflected by the high reflection processing film of the top surface portion 17a, becomes an upward reflected light beam P1 ′, and is condensed by the projection lens 12, so that the cut line Q ′ on the upper side of the light distribution pattern Q, as shown in FIG. Since the reflected light P1 ′ reflected by the highly reflective treatment film is collected on the lower portion Q ″, the illumination efficiency can be improved.

  The low reflection treatment film on the top surface portion 16a plays a role of mitigating a sudden light amount change at the boundary portion of the cut line Q 'on the upper side of the light distribution pattern Q.

Reference symbol P1 ″ indicates a light beam that is directed downward without being shaded by the shade 13.
(Example 2)
In the second embodiment, the shade 13 is composed of a single plate 18 as shown in an enlarged view in FIG. 5, and a flat surface extending in the optical axis direction is formed on the top surface portion 18 a of the plate 18. A low reflection treatment film 18a ′ made of black paint or the like is formed on the portion from the projection lens 12, and a high reflection treatment film 18a ″ is formed on the portion of the flat surface from the bulb 11. The surface portion 18a extends from the end edge 19a from the projection lens 12 along the optical axis direction to the bulb 11 side beyond the focal point F1.

  According to the projector type headlamp 10, the reflected light P1 ′ reflected by the high reflection processing film is condensed on the inner portion Q ″ of the cut line Q ′ portion on the upper surface side of the light distribution pattern Q as in the first embodiment. Therefore, the illumination efficiency can be improved.

Further, since the low reflection treatment film 18a ′ is formed beyond the focal point F1 of the projection lens 12, the degree of freedom of the assembling is also ensured when the shade 13 is assembled into the lamp.
(Example 3)
6 to 11 are explanatory views of a third embodiment of the projector-type headlamp 10 according to the present invention. In the lamp, a shaft 19 is provided as shown in FIGS. 6 and 7, and the shade 20 is in a low beam state. In order to enable switching of the light distribution characteristics between the high beam and the high beam, the shaft 19 is rotatably provided.

  A rod 22 of a solenoid 21 is connected to one end portion of the shade 20, and a top surface portion 20 a is provided to the other end portion of the shade 20. The shade 20 is rotated about the shaft 19 by the reciprocating movement of the rod 22, and the top surface portion 20a faces the flat surface 20a ′ extending in the horizontal direction and the projection lens 12 and is flat as shown in FIG. An inclined surface 20a ″ that is inclined downward from the surface 20a ′ is formed.

  The flat surface 20a ′ and the inclined surface 20a ″ are formed with a highly reflective treatment film such as aluminum vapor deposition. The inclination angle θ1 of the inclined surface 20a ″ with respect to the flat surface 20a ′ is a projection lens at the time of low beam as shown in FIG. 12 is larger than the angle θ2 formed by the straight line L connecting the lower end 12a and the focal point F1 with respect to the flat surface 20a ′. The bending line K between the flat surface 20a 'and the inclined surface 20a "is located on the bulb 11 side with respect to the focal point F1.

  According to the projector-type headlamp 10 according to the third embodiment, at the time of a low beam, the light beam P2 emitted from the bulb 11 and reflected by the elliptic mirror reflecting surface 15 and going downward is reflected by the flat surface 20a ′ and heads upward. Since this light beam is converted into a light beam and condensed by the projection lens 12, as shown in FIG. 10, it is flat on the lower portion G ″ of the cut line G ′ above the light distribution characteristic G as in the first embodiment. The reflected light P2 (see FIG. 6) reflected in the upward direction by the surface 20a ′ is collected.

  Further, when the high beam is used, the shade 20 is rotated with the shaft 19 as a fulcrum, and the light beam directed downward from the lower end of the projection lens 12 is reflected by the inclined surface 20a ″ in the upward direction during the low beam. As shown in FIG. 5, the reflected light beam P2 ″ reflected by the inclined surface 20a ″ and going upward is condensed by the projection lens 12, so that the cut line G ′ can be blurred at the time of the traveling beam.

  According to the third embodiment, the light flux P3 that is directed downward from the lower end 12a of the projection lens 12 can be reflected upward using the inclined surface 20a ″ at the time of the high beam, and can be used effectively. be able to.

  Further, since the rotation of the valve 11 during high beam can be reduced, the movable mechanism can be reduced in size.

It is sectional drawing which shows the outline | summary of the projector-type headlamp for the conventional motor vehicles. It is sectional drawing which shows the outline | summary of the projector type headlamp concerning Example 1 of this invention. It is an enlarged view of the shade part shown in FIG. It is a figure which shows the light distribution characteristic of the projector type headlamp shown in FIG. It is the elements on larger scale of the shade of the projector type headlamp concerning Example 2 of this invention. It is sectional drawing which shows the outline | summary of the projector type headlamp concerning Example 3 of this invention, Comprising: It is a figure which shows the state at the time of a low beam. It is sectional drawing which shows the outline | summary of the projector type headlamp concerning Example 3 of this invention, Comprising: It is a figure which shows the state at the time of a high beam. It is the elements on larger scale of the top | upper surface part of the shade shown to FIG. 6, FIG. It is explanatory drawing for demonstrating the angle which the flat surface and inclined surface shown in FIG. 7 make. It is explanatory drawing of the light distribution characteristic of the projector type headlamp shown in FIG. It is explanatory drawing of the light distribution characteristic of the projector type headlamp shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Projector type headlamp 11 ... Bulb 12 ... Projection lens 17 ... Shade 17a ... Top surface part F1 ... Focus

Claims (3)

  In the projector-type headlamp in which a shade having a top surface portion is provided in the lamp between the bulb and the projection lens, and a flat surface facing the optical axis connecting the bulb and the projection lens is formed on the top surface portion. A projector-type headlamp for an automobile, wherein a light reflection treatment film is formed on the flat surface closer to the bulb than the focal position of the projection lens.   The shade can be rotated to switch light distribution characteristics between a low beam and a high beam, and an inclined surface that faces the projection lens and is inclined downward from the flat surface is formed on the top surface portion. The projector-type headlamp for an automobile according to claim 1, wherein a light reflection treatment film is formed on the inclined surface.   The projector-type headlamp for an automobile according to claim 2, wherein an inclination angle with respect to the flat surface is larger than a straight line connecting a lower end of the projection lens and the focal point.

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