JP2009245600A - Projector type headlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a following problem: in a conventional projector type headlight, although a hole for passing light reflected by the lower half of a reflecting surface is provided in the vicinity of a shade in order to read an overhead sign, this hole also passes light from the upper half of the reflecting surface, and therefore, an eaves must be provided at the upper end of the shade forming a brightness and darkness boundary line, precise processing is required, and the processing is difficult. <P>SOLUTION: An overhead sign-reflecting surface is provided in part of the upper half of a reflecting surface, and a direction converting reflecting surface to direct light from the overhead sign-reflecting surface to a prescribed direction is provided in the front of the shade. Accordingly, no hole is required in the shade for forming a light distribution, no precise processing is required, and a structure is simplified. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to the light distribution characteristics of a projector-type headlamp, and more specifically, for example, a projector-type display panel which is called an overhead sign and is displayed directly above a route. The present invention relates to a configuration for making reading easier by changing the configuration of the headlamp.

  FIG. 7 shows an example of the configuration of a conventional projector-type headlamp 90 of this type, and the upper half of the elliptical reflecting surface 92 of light from the light source 91 originally placed at the first focal point F1. The shade 93 that shields the lower half portion of the elliptical reflecting surface 92 is installed in the vicinity of the second focal point, utilizing the characteristic that the light reflected at the second focal point F2 is focused. Therefore, all light from the lower half of the elliptical reflecting surface 92 is shielded by the shade 93.

  Further, for example, the focal point of the projection lens 94 formed as an aspheric lens is also set at or near the shade 93, so that the light reaching the projection lens 94 has a lower chord half shielded by the shade. After being projected through the projection lens 94, the top, bottom, left and right are reversed, so that the irradiation light is a semicircular shape of an upper chord and does not contain any upward light.

  Therefore, since it becomes difficult to read signs, guide plates (overhead signs), etc. provided on the lane, an opening 93a having an appropriate shape is provided near the upper end of the shade 93 in order to solve this point. It is possible to read the above overhead sign, assuming that a part of the light reflected by the lower half of the elliptical reflecting surface 92 reaches the projection lens 94 and irradiates the upward light UL.

In this case, the light reflected by the upper half of the elliptical reflecting surface 92 also reaches the opening 93a, and the shape of the light distribution characteristic may be distorted. Therefore, the upper end of the shade 93 faces the light source 91. A light shielding plate 93b is provided in a bowl shape extending obliquely downward.
JP 2003-297117 A

  However, although the above-described configuration certainly improves the readability of the overhead sign, the position of the opening 93a provided in the shade 93 and the elliptical reflecting surface 92 that allows light to enter the opening 93a. The reflection position from the light source, the positions of the light source 91 and the light shielding plate 93b, and the like are related to each other, and the amount of upward light and the irradiation direction are restricted.

  In particular, in recent years, in Japan, there is a requirement for a prescribed light amount in the upward direction of 0.5 ° and the right direction of 1.5 °, and it is required that the overhead sign can be read from a distance. If a considerable accuracy cannot be guaranteed, there is a problem that there is a high possibility that the problem of dazzling on the oncoming vehicle will occur.

  The present invention provides a projector-type vehicle headlamp comprising a light source, an elliptical reflector, a shade, and a projection lens as a specific means for solving the above-described conventional problems. The portion is provided with a reflection surface for overhead sign distribution that reflects light toward the front of the shade, and the light from the reflection surface for overhead sign reaches the front of the shade from the reflection surface for overhead sign. A reflection surface for overhead sign direction conversion that reflects light in the direction of the projection lens as substantially horizontal is provided, and the shade is formed of two plate-like members, and in the region that forms the light distribution shape on the shoulder side, The two sheets are closely formed as curved surfaces that match the focal curve of the projection lens, and form a light distribution shape on the opposite lane side. Then, the problem is solved by providing a projector-type headlamp, wherein each of the shades is provided at an appropriate interval with respect to the focal curve of the projection lens. .

  According to the present invention, an overhead sign light direction reflecting surface is provided in a part of the upper half of the elliptical reflector, and the light from the overhead sign light distribution reflecting surface is reflected in front of the shade. In addition to forming a light distribution shape for an overhead sign for short distance with these, a illuminance that irradiates light in an appropriate position of the shade at 0.5 U on the opposite lane and in the 1.5H direction By providing an increase hole to form a light distribution for an overhead sign for a long distance, the overhead sign can be easily read from a long distance or a short distance.

  Next, the present invention will be described in detail based on the embodiments shown in the drawings. FIG. 1 is a cross-sectional view of a projector type headlamp 1 according to the present invention. The projector type headlamp 1 has a light source 2 which is a discharge arc of a metal halide discharge lamp, for example, aligned with a first focus. A shade 4 for shielding light reflected mainly by the lower half of the elliptical reflective surface 3 is provided in the vicinity of the second focal point of the elliptical reflective surface 3. The light arranged in the desired shape in 4 is projected in the irradiation direction by the projection lens 5 to obtain the light distribution characteristic, which is almost the same as the configuration of the conventional projector type headlamp.

  Here, in the projector type headlamp 1 of the present invention, an overhead sign light distribution reflection surface 3a is provided in a part of the upper half of the elliptical reflection surface 3, and this overhead sign light distribution reflection surface is provided. 3a is provided, and the position where this overhead sign light distribution reflecting surface 3a is provided is in front of the light source 2, and the light from the light source is in front of the shade 4 as will be described in detail later. It is supposed to reflect toward the.

  Incidentally, the shape of the reflecting surface of the overhead sign light distribution reflecting surface 3a has a relatively large arc in the direction orthogonal to the optical axis Z of the projector type headlamp 1 of the present invention, and is in the parallel direction. Is a concave mirror having an arc smaller than the above-described orthogonal direction, and focuses the cross-sectional shape of the reflected light into, for example, an ellipse or an ellipse.

  The light path of the reflected light from the overhead sign light distribution reflecting surface 3a and the position where the light emitted from the light source 2 in the front direction is blocked by the shade 4 is in the overhead sign direction. A conversion reflecting surface 3 b is provided, and reflects light from the overhead sign light distribution reflecting surface 3 a toward the projection lens 5.

  What is shown in FIG. 2 is an example of the shape of the light distribution characteristic D2 obtained by the reflection surface 3a for overhead sign light distribution, the reflection surface 3b for overhead sign direction conversion, and the projection lens 5. The reflection surface shape of the reflection surface 3a for overhead sign light distribution or the reflection surface 3b for overhead sign direction conversion is appropriate, so that the light distribution toward at least the opposite lane is warped upward at both ends. It is preferable to keep it.

  3 and 4 show a second characteristic configuration point of the projector-type headlamp 1 according to the present invention. In the present invention, the shade 4 has two thin plates, that is, light sources. Formed by a combination of a main shade 4a disposed on the side and a subshade 4b disposed on the projection lens side. Further, when the projector type headlamp 1 is viewed from above, it is asymmetric with respect to the optical axis Z. It is said that the shape.

  First, the curve LF in FIG. 3 shows the curvature of field of the projection lens 5, and the focal point of the projection lens 5 exists along this curve LF. Therefore, if the shade 4 is formed along the curve LF, a sharp light / dark boundary line is projected on the irradiation light. In the present invention, on the road shoulder side, both the main shade 4a and the subshade 4b are formed along the curve LF. FIG. 4 is a front view of the shade 4 as viewed from the projection lens 5 side.

  In the present invention, on the opposite lane side, the main shade 4a and the subshade 4b are formed so as to have an appropriate distance from the field curvature LF. By doing so, particularly in the vicinity of the optical axis Z, the projection lens 5 is out of focus (so-called out-of-focus) with respect to the main shade 4a and the subshade 4b, and the light / dark boundary The sharpness of the line is lost, and at the same time the brightness of this part is dimmed. Therefore, the on-coming vehicle is not focused and the light having the same directionality does not reach, and the feeling of dazzling for the driver of the on-coming vehicle is also reduced. (See DB section in Fig. 6)

  In the present invention, in addition to the above, an illuminance increasing hole 4c is provided in the vicinity of the optical axis Z of the main shade 4a, and a part of the light transmitted through the illuminance increasing hole 4c is blocked by the sub shade 4b. However, a part of the transmitted light is incident on the end of the projection lens, and the position of (0.5U / 1.5R: in the case of a vehicle for left-hand traffic) is shown in FIG. The light distribution D3 to be irradiated is used.

  Here, by providing the illuminance increasing hole 4c, for example, it is possible to check the oncoming lane in a state where no dazzling occurs, or to check an overhead sign in the distance, and the practicality is remarkably improved. In the Japanese standard, the illuminance at the position (0.5 U / 1.5 R) is defined.

  The main shade 4a and the subshade 4b formed as described above are integrated by an appropriate means such as spot welding after being processed into a predetermined shape. During the use of the projector headlamp 1, the main shade 4a and the sub shade 4b are prevented from moving between each other.

  6 shows the light distribution characteristic D1 of the projector-type headlamp 1 described above. In the shade 4, the main shade 4a and the secondary shade 4b are used, and the light and dark boundary line is formed on the road shoulder side. The oncoming lane side has a light distribution that gently changes the brightness of the oncoming lane, while avoiding excessive dazzling of pedestrians. To reduce the dazzling that occurs.

  In addition, the illuminance increasing hole 4c is provided in the shade 4a to irradiate light in the direction of (0.5U / 1.5R), making it easy to check oncoming vehicles, visually check and read the overhead sign in the distance, This makes it easy to operate the system and also satisfies domestic standards.

  In the configuration of the present invention, if the shade 4 and the overhead sign direction changing reflecting surface 3b are integrated, the shade 4 is moved downward when traveling on a suburb or a mountain road. By doing so, there is no substantial obstacle to the optical path of the light emitted from the light source 2 and reflected on the elliptical reflecting surface 3, and for example, it is possible to switch to the traveling beam by a simple mechanism such as a solenoid.

  At this time, particularly on the opposite lane side, the shade 4 is displaced from the field curvature LF, and the road surface that is darkly irradiated in a so-called defocused state is irradiated with direct light by switching. Therefore, the switching effect becomes clear and the visibility in the oncoming lane direction is improved.

It is sectional drawing which shows the structure of the projector type headlamp which concerns on this invention. It is explanatory drawing which shows the 1st overhead sign light distribution shape of the projector type headlamp which concerns on this invention. It is a top view which shows the shade part of the projector type headlamp which concerns on this invention. It is a front view of a shade part similarly. It is explanatory drawing which shows the 2nd overhead sign light distribution shape of the projector type headlamp which concerns on this invention. It is explanatory drawing which shows the shape of the total light distribution of the projector type headlamp which concerns on this invention. It is sectional drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projector type headlamp 2 ... Light source 3 ... Elliptic reflection surface 3a ... Reflection surface for overhead sign light distribution 3b ... Reflection surface 4 for overhead sign direction conversion ... Shade 4
4a ... Main shade 4b ... Sub shade 4c ... Illuminance increase hole 5 ... Projection lens

Claims (3)

In a projector type vehicle headlamp comprising a light source, an elliptical reflector, a shade, and a projection lens,
An overhead sign light distribution reflecting surface that reflects light toward the front of the shade is provided in a part of the upper half of the elliptical reflector, and the light from the reflecting surface for the overhead sign reaches the front of the shade. Is provided with a reflecting surface for changing the direction of overhead sign that reflects light from the reflecting surface for overhead sign in a substantially horizontal direction toward the projection lens,
The shade is formed by two plate-like members, and in the region where the light distribution shape on the shoulder side is formed, the two sheets are closely formed as a curved surface matching the focal curve of the projection lens, and the opposite lane The projector-type headlamp is characterized in that each shade is provided at an appropriate interval with respect to the focal curve of the projection lens in a region where the light distribution shape on the side is formed.   The shade on the light source side is provided with an illuminance increasing hole for irradiating light in the direction of 0.5 U and 1.5 H (R, L) on the opposite lane side when projection is performed by the projection lens. The projector type headlamp according to claim 1.   3. The projector type headlamp according to claim 1, wherein the two shades are movable, and a traveling beam and a passing beam can be switched.

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