JP5844088B2 - Projector headlight in which the light intensity gradient of the light / dark border is attenuated according to the purpose - Google Patents

Description

  The present invention relates to an automotive projector headlight according to the preamble of claim 1. Such an automobile headlight is known from DE 102008023551A1.

  A projector headlight generally includes at least one light source, an optical element that collects light from the light source, a light shielding plate with a light shielding plate edge, and an imaging optical system. This optical element is provided and arranged to direct the collected light toward the edge of the light shielding plate. As a result, a first light distribution pattern divided by the light shielding plate edge is generated at the light shielding plate edge, and this first light distribution pattern is imaged in the front view of the headlight by the imaging optical system. The In this case, the light shielding plate edge is imaged as a light / dark boundary between a relatively bright area and a relatively dark area in the second light distribution pattern.

  The light intensity gradient that occurs when crossing the light-dark boundary is an important parameter when planning and designing automobile headlights. If the value of the light intensity gradient is high, the contrast is strong and it is recognized as a clear light / dark boundary. On the one hand, there is a legal minimum requirement for the sharpness of the light / dark boundary that must be observed. On the other hand, a blurred light / dark boundary is more comfortable for the driver. When the contrast of the transition portion becomes small, the feeling of instability becomes less than when the contrast of the transition portion is strong, particularly when the light / dark boundary moves violently and vertically as occurs on a wavy road surface. Therefore, the fact that the contrast is small in the transition portion acts in the direction of reducing fatigue.

  In the case of the projector headlights mentioned at the beginning, the light intensity gradient at the boundary between light and dark is adjusted in various regions on the surface of the imaging optical system realized as a lens. have. Each of these regions is partitioned into periodic rasters of individual cells, each of which scatters light passing through the surface for a purpose. According to DE 102008023551A1, the proposed object allows predictable and dark adjustments of the light and dark boundaries compared to random roughening of the lens surface and periodic modification of the lens surface. .

  It is very laborious and expensive to produce the calculation and to produce a tool that can produce the calculated lens to achieve the calculation result. Against this backdrop, the problem of the present invention is to show what the projector headlight of the type mentioned at the beginning enables predictable sharpness of the light / dark boundary and adjustment for the purpose with less effort. is there.

  This problem is solved by the features of claim 1. In the projector headlight of the present invention, the light-shielding plate has a protrusion and / or a notch with one side opened at the light-shielding plate edge, and / or the light-shielding plate has a plurality of first holes separated by closed edges. Provided in the light shielding plate, these holes are spaced from the edge of the light shielding plate, and this interval is less than one fifth of the width of the light shielding plate.

  Usually, the light shielding plate edge is clearly imaged in the front field of view of the headlight as a light / dark boundary in the second light distribution pattern. For this reason, the light shielding plate edge is usually disposed so as to be located near the focal point of the imaging optical system. In addition, the light-shielding plate edge clearly separates a region that becomes a shadow of the light-shielding plate and a region that does not become a shadow of the light-shielding plate and therefore is irradiated by the second light distribution pattern.

  With the present invention, this sharp separation is weakened and blurred. Both projections make a shadow of light, but this light should contribute to illumination in a bright area below the light / dark boundary in the case of a conventional light shielding plate. On the other hand, any notch and any hole allows light to pass, which should be shielded in the case of a conventional shading plate. In other words, the light intensity in the bright area is reduced on average, and the light intensity in the originally dark area is increased on average compared to the conventional light shielding plate.

  At the same time, these protrusions protrude beyond the average transition line of the shading plate edge, while the cuts and holes are left behind this average transition line. Speaking of the position of the imaging optical system with respect to the focal point, the positions of the protrusions, cuts and holes inevitably deviate from the average transition line of the light shielding plate edge.

  Since the average transition line of the light shielding plate edge is near the focal point of the imaging optical system, when it is assumed that a clear image is formed, if the positions of the protrusions, cuts, and holes are out of position, these Imaging results in reduced sharpness. As a result, even if the second light distribution pattern is generated in the front view of the headlight, this light distribution pattern has a small sharpness and contrast at the light / dark boundary, and in that case, the details of the light shielding plate that causes the light distribution, Projections and / or cuts and / or holes are not clearly imaged. Clear imaging is undesirable.

  Although it is desired to reduce the sharpness of the light / dark boundary, in the present invention, this is obtained by the shape of the light shielding plate. Compared with the imaging optical system, the light shielding plate is a component that is relatively easy to form and manufacture. As a whole, this makes it possible to predict the sharpness of the light / dark boundary and adjust it to the purpose with less effort.

  One preferred embodiment is characterized in that the imaging optical system is a non-rotationally symmetric lens with respect to the optical axis or a non-rotationally symmetric and astigmatic lens system with respect to the optical axis. Astigmatism refers to an imaging error in which a point is imaged not as a point but generally as an elliptical surface. Such an imaging error is already caused by a light beam incident on a rotationally symmetric lens from a point located outside the optical axis, if it is relatively small. In the case of a non-rotationally symmetric lens, astigmatism usually appears more strongly. This enhances the blurring of the imaging, which in this embodiment contributes to the smearing of the shading plate edges that are hole, zigzag or wave modified. Clear imaging is undesirable.

  It is also preferred that the imaging optical system has a different focal point in the plane or direction extending along the light shielding plate edge on the optical axis than in the plane or direction extending across the light shielding plate edge. As a result, the light distribution pattern generated between the light-shielding plate edge and the imaging optical system can be imaged with clearness different in both directions. This contributes to preventing the projections, cuts, and holes that the light shielding plate has near the light shielding plate edge from being resolved when the first light distribution pattern is imaged onto the second light distribution pattern. To do.

  Another preferred embodiment is characterized in that the light shielding plate edge is located closer to one of the two focal points of the imaging optical system on the optical system than the other of the two focal points of the imaging optical system on the optical axis. To do. In other words, the light-shielding plate edge is located closer to one of the two focal points rather than being located at an equal distance from both focal points. The shading plate can basically be arranged in a horizontal position or a vertical position in the headlight or in an intermediate position between these positions. Depending on the position of the light shielding plate, it is advantageous to place the light shielding plate at one of the two focal points and closer to the other of the two focal points in order to make the resolution of protrusions, notches and holes as blurred as desired. obtain.

  It is also preferable to arrange the light shielding plate edge closer to the focal point far from the imaging optical system than the focal point not far from the imaging optical system in the optical axis direction. The advantage of this embodiment is that the protrusions, cuts, and holes in the light shielding plate are resolved with the second light distribution pattern, particularly when the light shielding plate is arranged horizontally rather than vertical in the headlight. Therefore, to make it invisible or at least not clearly visible.

  The shading plate is located in a plane that forms an angle of less than 20 °, in particular less than 10 °, more particularly 0 ° with the plane determined by the shading plate edge and the optical axis, and the shading plate is a reflective surface It is also preferable to have Due to this position and the reflective shape, the light initially shielded by the light-shielding plate is reflected by the light incident surface of the imaging optical system and refracted by the imaging optical system to brighten the second light distribution pattern. Can be put into the area. This can improve efficiency. The efficiency is defined as a quotient obtained by using light emitted from the light source as a denominator and light forming the light of the second light distribution pattern as a numerator.

  Another preferred embodiment is that the shading plate comprises a plurality of bulges and / or depressions and / or further holes in its plane, which are located further from the shading plate edge than the first hole. It is characterized by. This structure is preferably used to modify the light distribution pattern determined by the basic shape of the light shielding plate. This is because, for example, the specified numerical value of the light intensity is observed at a specific measurement point inside the originally dark region of the light distribution pattern. These measurement points located above the light / dark boundary are used, for example, to ensure a specific illumination intensity of the traffic sign (a numerical value for the overhead sign).

  It is also preferred to increase the amplitude of the notches and / or protrusions, the area and / or number and / or spacing of the first holes as the spacing from the optical axis increases. According to this embodiment, as the light / dark boundary in the second light distribution pattern, the central region is relatively clear, but the peripheral region is relatively unclear. Thereby, for example, the vertical motion of the light / dark boundary occurring on the undulating road surface appears more strongly in the central region than in the peripheral region. As a result, the driver is strongly and intuitively focused on the central area, which is desirable for reasons of driving safety.

  In the headlight according to the present invention, the light-shielding plate edge has a central region located close to the optical axis, and in this region, the light-shielding plate does not have a protrusion on the light-shielding plate edge or a notch opened on one side, and a closed peripheral edge In the case where the light shielding plate does not have the first hole divided into two, the same advantage as described above can be newly obtained or supplementarily obtained depending on the shape of the headlight.

  Another preferred embodiment contemplates providing light scattering surfaces in the form of local bulges and / or depressions on the light entrance and / or light exit surfaces of the imaging optics.

  This embodiment opens up additional degrees of freedom when designing headlights. This is because a modification of the projector system is required to reduce the sharpness desired at the light / dark boundary, but this embodiment makes it possible to divide the system into a light shielding plate and an imaging optical system. It is. This division reduces the size of modification required for each component. Therefore, in the lens, in some cases, a scattering structure distributed periodically or randomly on the lens surface is sufficient. This reduces labor and costly manufacturing processes if the scattering structures are calculated individually. At the same time, this lens reduces the sharpness of the imaging of the area structured according to the invention in the vicinity of the edge of the shading plate. This contributes to the fact that notches, protrusions, and holes in the light shielding plate are not resolved in the second light distribution pattern, or contributes to a lower resolution than in other cases, which is a desirable effect.

  Other advantages are set forth in the dependent claims, the following description and the attached drawings.

  Obviously, the features listed above, and further described below, are not limited to the combinations listed above, but other combinations or just one would also leave the scope of the present invention. Can be used without any problem.

  Embodiments of the invention are shown in the drawings and are explained in more detail in the following description. In this case, all show schematic diagrams.

1 is a projector headlight as a technical environment of the present invention. It is a light shielding plate known in the prior art. It is an Example of the light-shielding plate of the headlight by this invention. It is an example of the light distribution pattern with a light-dark boundary. Illustrates the illuminance course as it crosses the light / dark boundary of the light distribution pattern in qualitative form. Two cut surfaces of a non-rotationally symmetric astigmatism lens are shown along with their respective optical paths. The arrangement of the elements of the projector headlight according to the present invention is shown together with the light shielding plates arranged vertically. The arrangement of the elements of the projector headlight according to the present invention is shown together with the light shielding plates arranged horizontally. 3 shows another embodiment of the light shielding plate of the headlight of the present invention.

  The same reference number in different drawings indicates the same element, or at least an element with the same function.

  Specifically, FIG. 1 shows a projector headlight 10 for an automobile. The headlight includes a light source 12, an optical element 14 that collects light 15 of the light source 12, a light shielding plate 16 having a light shielding plate edge 18, and imaging optics. A system 22 is provided. The illustrated elements 12, 14, 16, and 22 are disposed along the optical axis 31 of the headlight 10. At this time, the optical element 14 converts the light 15 generated from the light source 12 into a light beam and blocks the light. Direct toward the plate edge 18. As a result, a first light distribution pattern which is in contact with the light shielding plate edge 18 and is divided by the light shielding plate edge 18 is generated.

  The imaging optical system 22 is provided and arranged so as to form an image of the first light distribution pattern as a second light distribution pattern 24 in the front field of view of the headlight 10. In this case, the light shielding plate edge 18 is imaged in the second light distribution pattern 24 as a light / dark boundary 26 between the relatively bright region 28 and the relatively dark region 30 of the second light distribution pattern 24. .

  This image formation is performed so that the light shielding plate 16 is inverted and reversed left and right and is imaged in the front field of view of the automobile. Accordingly, the brighter region 28 is located below the horizontal line when the projector headlight 10 is desired to satisfy the low beam function. By locating the darker region 30 above the horizon, the illusion of the oncoming vehicle is avoided or at least reduced. The light shielding plate edge 18 usually has an asymmetrical specification. For example, when the light shielding plate edge 18 has a portion that is lowered from the optical axis 31 by an angle of 15 °, this is imaged as an rising edge in the second light distribution pattern 24. Is done. Thereby, as is known, it is possible to sufficiently illuminate the side surface of the automobile that is not the oncoming side. For other embodiments, an angle of 0 °, or 45 °, or 90 ° is intended.

  In the case of the first embodiment, the light source 12 is an incandescent bulb or a discharge lamp. In the case of this embodiment, the optical element 14 that collects light is preferably a composite ellipsoid whose basic shape is an ellipsoid. The light source 12 is preferably arranged at one focal point of the ellipsoidal reflector. A light shielding plate edge 18 is disposed at the other focal point of the ellipsoidal reflector. Since the light emitted from the light source 12 isotropically is directed to the second focal point by the reflector 14, the first luminous intensity distribution pattern that is strongly luminous is generated at the focal point. It is delimited by the light shielding plate edge 18.

  In another embodiment, the light source 12 is a semiconductor light source or an arrangement of a plurality of semiconductor light sources. Semiconductor light sources, particularly light-emitting diodes, are usually semi-infinite radiators and differ in this respect from incandescent bulbs or discharge lamps, which can be regarded almost as light sources 12 that emit isotropically. For this reason, another condensing element 14 is used for an embodiment having a semiconductor light source as the light source 12.

  When the semiconductor light source is the light source 12, unlike the composite ellipsoidal reflector that more or less wraps the light source 12, only one reflector 14 with one side closed is required, and this reflector also wants to have an ellipsoid as its basic shape. This means that when applied to the illustration of FIG. 1, the lower half of the reflector 14 illustrated therein can also be removed.

  Unlike the half-shell reflector as the condensing optical element, use an attachment optical system made of a light guide material for the light source 12 realized as an arrangement of semiconductor light sources or a plurality of semiconductor light sources. I can do it too. This optical system takes in the light 15 of the light source 12, turns it into a light flux by refraction and internal total reflection generated inside the light guide material, and directs it toward the light shielding plate edge 18.

  The imaging optical system 22 is a condensing lens in one embodiment, and when the lens is disposed, the reflector side focal point is positioned in the region of the first light distribution pattern in contact with the light shielding plate edge 18. To. If it does so, the light-shielding plate edge 18 will be imaged in the front visual field of a motor vehicle as the clear light-dark boundary 26 in the 2nd light distribution pattern 24. FIG.

  FIG. 2 shows a light shielding plate 16 known from the prior art, which is arranged across the optical axis 31 in the headlight 10 and has a light shielding plate edge 18 extending almost smoothly as shown in FIG. Have. In this case, the light shielding plate edge 18 has a curvature as shown in FIG. This is because, in cooperation with the imaging optical system 22, a desired contour of the light / dark boundary 26 is obtained in the second light distribution pattern 24 in front of the automobile. In the case of the prior art, this smooth line is imaged as a sharp light / dark boundary 26.

  FIG. 3 shows various embodiments of the light shielding plate 32 of the headlight 10 according to the present invention. If it demonstrates individually, in the light-shielding plate 32 which FIG. 3 a shows, the light-shielding plate edge 34 has the notch 38 and the protrusion 40 which opened one side.

  As measured by the average transition line 36 of the light shielding plate edge, the protrusion 40 protrudes into a region where all light is transmitted in the case of a generally used light shielding plate as shown in FIG. That is, the projection 40 is a region located in the vicinity of the average transition line 36 of the light shielding plate edge 34 and shields light that is not shielded by the known light shielding plate 16. In contrast to this, the notch 38 that opens one side allows the light shielding plate 32 to pass through the light that should be shielded in the case of the light shielding plate 16 that is generally used.

  As a result, the light shielding plate 32 as shown in FIG. 3a reduces the light intensity in the first light distribution pattern generated in contact with the light shielding plate edge 34 above the average transition line 36, and the average transition line. Increase below 36.

  Exactly similar to the above is the object of FIG. The object of FIG. 3b differs from the object of FIG. 3a in that the protrusions 40 and the notches 38 produce a rounded peripheral edge in the case of FIG. 3b, but are linear in the case of the object of FIG. 3a. This is a point indicating a zigzag line with a sharp tip.

  Another embodiment shown in FIG. 3 c comprises a first hole 50 provided in the shading plate 32 just below the shading plate edge 34. In the light shielding plate 16 that is generally used, the light that should be shielded by the light shielding plate material passes through the light shielding plate through the holes 50 and affects the first light distribution pattern generated in the light shielding plate 32.

  All three embodiments of the light blocking plate 32 as shown in FIGS. 3a-c are characterized by the following. That is, the light shielding plate edge 34 has a central region 42 located near the optical axis 31, and in this region, the light shielding plate 32 has a projection 40 on the light shielding plate edge 34, a notch 38 that is open on one side, and There is also no first hole 50 delimited by a closed periphery in the light shielding plate 32. Therefore, in the central region 42, the light shielding plate 32 is not different from the light shielding plate 16 generally used. Therefore, in this central region, the light / dark boundary produced by the light shielding plate 32 cooperating with the commonly used components of the projector headlight 10 is different from the light / dark region produced by the projector headlight having the light shielding plate 16 used in general. There is no place.

  However, in the light distribution pattern, a difference occurs between the right and left peripheral regions of the light shielding plate edge. In these peripheral areas, the shading edge 34 has, for example, a zigzag line 46 shown in FIG. 3a or a wavy line 48 shown in FIG. 3b. Alternatively, in these peripheral regions, the first holes 50 in the light shielding plate 34 affect the first light distribution pattern. Next, this will be described in more detail with reference to FIGS. FIG. 4 shows a half of the second light distribution pattern 24 generated by the generally used light shielding plate 16 in the right half thereof. This light distribution pattern has a bright / dark boundary 26 that appears clearly in both the central region 42 and the right peripheral region.

  As compared with the above, FIG. 4 shows the light distribution pattern 24 produced by the light-shielding plate 32 in the left half of the same projector headlight as shown in FIGS. 3a, b, and c under the same conditions as those figures. . In this case, the clear bright / dark boundary 26 in other portions is blurred in the left peripheral region. This is shown by dividing the light / dark boundary 26 into three light / dark boundaries 26, 26 ', 26 ". In this case, each of the three lines 26, 26 'and 26 "corresponds to one constant illuminance. This means that the transition from light to dark appears clearly along the light / dark boundary 26 in the right half of the light distribution pattern 24, but in the left half of the light distribution pattern 24, its appearing area is slightly smaller. It is blurred over an angle.

  Self-evidently, this blurring of the light / dark boundary has been described with three isolux lines 26, 26 ', 26' ', but this is merely for the purpose of this description, in practice, It is possible to draw an arbitrary number of isolux lines by subdividing the classification of illuminance values.

  FIG. 5 shows the same relationship as above in the following way. In other words, the light intensity is represented along an angle value obtained by measuring the mixing of the light spots from the central axis, for example, the optical axis 31. In this case, the transition of the light intensity indicated by the solid line belongs to the generally used light shielding plate 16 and to the light distribution pattern 24 shown in the right part of FIG. This transition is characterized by a sharp light / dark boundary 26, and this light / dark boundary is imaged by a very steep transition of the curve 54 in the region of 0 ° with respect to the horizontal line in FIG. Unlike this very steep transition, the transition 56 shown by the dotted line has a small slope when the angle is 0 ° and in a very narrow angle range around this angle of 0 °. This means that if the light / dark boundary transitions correspondingly with a small slope, it is observed that the contrast decreases correspondingly and the sharpness decreases correspondingly.

  In the case of the projector headlight 10, the transition 56 shown by the dotted line is obtained by the following light shielding plate. That is, embodiments of these light shielding plates are shown in FIGS. 3a, 3b, and 3c, and these light shielding plates are characterized by the following. That is, the first light distribution pattern is affected outside the central region 42 in contact with the light-shielding plate edge 34 in the right and left peripheral regions of the light-shielding plate 32. In the case of a simple light shielding plate, the light reaching the shadowed area is increased, and in the case of another light shielding plate, the light reaching the area to be irradiated is decreased.

  FIG. 5 shows the above as follows. That is, the curve 56 belongs to the light-shielding plate 32 of the headlight of the present invention, and passes below the curve 54 slightly below the horizontal line, that is, where the numerical value is slightly less than 0 °. However, the curve 56 passes above the curve 54 at a numerical value above the horizontal line, ie, slightly above 0 °.

  As shown in FIG. 4, it is desired that the blur becomes stronger from the center of the light distribution pattern 24 toward the outer periphery. In FIG. 4, this blur is expressed by an increase in the interval between the isolux lines 26 ′, 26, 26 ″ from the inside toward the outside. Thereby, in the average transition line 36 of the light shielding plate edge 34, the amplitude of the notch 38 and / or the protrusion 40 and / or the area and / or the number and / or interval of the first holes 50 can be changed from the optical axis 31. As the interval increases, it increases.

  To widen and blur the light / dark boundary according to the purpose, the following is further required. That is, in connection with FIG. 3, it has been described that the region of the light shielding plate edge 34 of the light shielding plate 32 is structured by the notch 38 and / or the time 40 and / or the hole 50. When the light distribution pattern 24 is generated, it is required that it is not resolved. In other words, it is desired that the above-described structuring cannot be visually recognized by the second light distribution pattern 24. The desired effect here is supported by the astigmatism of the imaging optical system 22. Due to astigmatism, the point is generally imaged as an ellipse rather than as a point, and thus unclear.

  In order to properly design the blurring desired here, one embodiment intends to: The imaging optical system 22 is a lens 58 that is non-rotationally symmetric with respect to the optical axis 31 or a lens system that is non-rotationally symmetric and is astigmatism with respect to the optical axis. Such an embodiment is shown schematically in FIG. FIG. 6 a shows a first cross section 60 through such a non-rotationally symmetric lens 58. This cross section is cut along the optical axis 31 and in a direction crossing the light shielding plate edge 34. When the light shielding plate edge 34 is to be imaged with the second light distribution pattern 24 as a light / dark boundary located substantially horizontally, the cross section 60 becomes a vertical cross section.

  FIG. 6 b shows a second cross section 62 through the non-rotationally symmetric lens 58. This cross section is cut along the optical axis 31 and along the light shielding plate edge 34. When the light shielding plate edge 34 is to be imaged with the second light distribution pattern 24 as a light / dark boundary positioned substantially horizontally, the cross section 62 becomes a horizontal cross section. As is known, the focal length of a lens increases with less curvature.

  In the case of the object shown in FIG. 6, the lens 58 has a small curvature between the light incident surface and the light exit surface in the vertical cross section 60, and the focal length fv is particularly large accordingly. The focal length fv is an interval from the center plane of the lens 58 to the focal point 66 in FIG. The light beam 68 is a light beam that passes through the vertical cut surface corresponding to this interval.

  At the horizontal section 62, the lens 58 has a larger curvature and thus a shorter focal length fh. The focal point 64 located in the horizontal cross section is therefore closer to the lens 58 than the focal point 66 in the vertical cross section. A light ray 70 represents a light ray located in the horizontal cross section.

  The arrangement of the elements of the projector headlight of the present invention shown in FIG. 7 includes the vertically arranged light shielding plates 32 described with reference to FIG. 3 and the asymmetric lens 58 described with reference to FIG. .

  The lens 58 has an upper peripheral edge that is thicker than a lateral peripheral edge, and thus has a larger focal length in the vertical section than in the horizontal section. The light shielding plate edge 34 is preferably arranged so that one of the two focal points 66 and 64 of the lens 58 used here as the imaging optical system 22 is closer to the other focal point of the two focal points 66 and 64. Shall be. In one particularly preferred embodiment, when the light shielding plate edge 34 is disposed, the focal point 66 that is farther away from the imaging optical system 22 or the lens 58 when viewed in the direction of the optical axis 31 is used in the optical system 22. Alternatively, the light shielding plate edge is made closer to the focal point 64 which is not so far from the lens 58.

  Therefore, the light shielding plate edge 34 is located at the vertical focal point 66 of the astigmatism lens 58 in this embodiment. The horizontal focus 64 is between the focus 34 and the lens 58. In this case, the light shielding plate edge is clearly imaged in the vertical direction, but is unclearly imaged in the horizontal direction. If the horizontal focal point 64 is located at a sufficient distance from the vertical focal point 66, it is advantageous if the lens 58 is formed asymmetrically in terms of rotational symmetry. In such a case, the zigzag or corrugated shape of the shading plate 32 or shading plate edge 34 or the shape with the first hole 50 is no longer resolved. The notches 38, protrusions 40 and holes 50 are rather horizontally blurred, which is desirable in this case.

  With respect to the light source 12 and the optical element that collects the light of the light source 12, FIG. Fig. 4 illustrates an embodiment including an arrangement. These attachment optical systems 80 and 82 are made of, for example, PMMA (polymethyl methacrylate) or PC (polycarbonate) as a conductive material. Since these materials have a refractive index higher than that of air, the light beam emitted from any semiconductor light source has its aperture angle reduced from, for example, 90 ° to about 40 ° when incident on the assigned attachment optical system. This angle is related to the deviation of the peripheral ray of the diffusion cone relative to the central axis of the diffusion cone from time to time.

  The condensing action of the attachment optical system is based on the above effect. By forming the side surface as a totally reflective reflecting surface, the light beam can be made highly efficient. This is because total internal reflection is performed almost without loss, unlike reflection on a metal surface as a mirror surface.

  The total reflection side surface and the surfaces of the attachment optical systems 80 and 82 used as the light exit surface on the light shielding plate 34 side are preferably adapted to the following purposes depending on their geometry. That is, the light emitted from the semiconductor light sources 72 and 74 is converted into a luminous flux and directed toward the light shielding plate edge 34. As a result, a first light distribution pattern divided by the light shielding plate edge 34 is generated at the light shielding plate edge 34. Is the purpose.

  Then, the first light distribution pattern is imaged as a second light distribution pattern 24 in the front view of the headlight 10 by the lens 58 as the imaging optical system 22. In this case, the light shielding plate edge 34 is imaged as a light / dark boundary 26 between a relatively bright region and a relatively dark region in the second light distribution pattern 24.

  FIG. 8 shows a particularly preferred embodiment of the arrangement of the elements of the projector headlight according to the invention. Similar to the object of FIG. 7, the object of FIG. 8 also has semiconductor light sources 72, 74, 76, 78 as the light source 12, and attachment optical systems respectively assigned as condensing, luminous flux, and directing elements. 80, 82, 84, 86 are provided. It is not important in this case that the numbers of semiconductor light sources and attachment optical systems differ between the objects shown in FIGS. However, an important difference is the arrangement of the light shielding plate 32.

  In the case of the object of FIG. 7, the light shielding plate 32 is arranged perpendicular to the optical axis, particularly perpendicular to the optical axis, but FIG. 8 is arranged parallel to the optical axis 31 of the light shielding plate 32, that is, horizontally. Indicates. Therefore, FIG. 8 shows an embodiment in which the light shielding plate 32 is particularly positioned on the following surface. That is, a plane that is determined by the light shielding plate edge 34 and the optical axis 31 and a plane that forms an angle of less than 20 °, particularly a plane that forms an angle of less than 10 °, and more particularly a plane that forms an angle of 0 °.

  The present invention seeks to widen the light / dark boundary and reduce the light intensity gradient at the light / dark boundary in the peripheral region of the second light distribution pattern 24 in front of the automobile. In this case, the angular position of the light shielding plate 32 is not so important. Absent. In that case, from the request for conformity to the position, the light shielding plate of the lens 58 used as the light shielding plate edge side of the imaging optical system 22 or the light incident surface on the light shielding plate edge side of the imaging optical system 22 may be used. In some cases, it may be desirable to have a curvature similar to that of the side light incident surface. In the case of the object of FIG. 8, such a curvature is recognized. In the case of the object of FIG. 7, such a curve slightly moves the vertical outer edge of the light shielding plate 32 in the direction of the lens 58, while the central region of the light shielding plate edge 34 is the vertical cross section of the lens 58. Could be achieved by staying at the focal point 66 of

  Compared with the vertical arrangement of the light shielding plate 32 in FIG. 7, the original advantage of the arrangement of the light shielding plate 32 shown in FIG. 8 is an improvement in efficiency. In this case, efficiency refers to the proportion of the amount of light that is imaged on the light distribution pattern 24 in front of the automobile, out of the amount of light emitted from the light source 12. In the case of the object shown in FIG. 7, the amount of light inevitably stays below one optimum value. This is because the vertically arranged light shielding plate effectively shields a part of the first light distribution pattern generated at the light shielding plate edge 34.

  In the case of the object shown in FIG. 8, such shielding is certainly performed as follows. That is, the light shielding plate 32 positioned horizontally is prevented from reaching the dark region 30 desired for the light distribution pattern 24 of the light incident on the light shielding plate. However, the light shielding plate 32 positioned horizontally allows not only that but also the reflected light to be reflected toward the light incident surface of the lens 58 on the light shielding plate 32 side. In this case, it is preferable to form the lens 58 so that the light is directed to the bright area 28 of the second light distribution pattern 24 in front of the automobile by refraction.

  Accordingly, in the case of the object of FIG. 8, less light is lost than in the case of the object of FIG. This efficiency advantage of FIG. 8 can be further improved by making the surface of the light shielding plate 32 on the light exit surface side of the attachment optical systems 80, 82, 84, 86 reflective. This is preferably obtained by a metallic mirror-like coating, which has been known for decades as a reflector production process. Since light utilization becomes more efficient, the embodiment including the horizontally arranged light shielding plate 32 is particularly suitable for use with a semiconductor light source as the light source 12. This is because, even if the number of semiconductor light sources is limited, the same amount of light flux as can be expected from a discharge lamp and / or a halogen lamp can be easily obtained.

  Another advantage of the light shielding plate 32 positioned horizontally is that when the light shielding plate 32 is assembled horizontally, the lower part of the projector headlight can be used for other functions. Therefore, it is particularly advantageous to use the upper part for an additional low beam and the lower part for an additional high beam. In this case, the light-shielding plate works with either a low beam or a high beam. This also blurs the structurally recognizable separation line between the additional low beam and the additional high beam.

  One preferred embodiment is characterized in that the shading plate is movable. In this case, the light shielding plate is slid or tilted along the surface of the light shielding plate. In the embodiment shown in FIG. 7, the light shielding plate is slid downward. In the embodiment shown in FIG. 8, the light shielding plate is slid rearward. In the case of an embodiment with a tiltable light-shielding plate, the light-shielding plate is tilted about an axis that is sufficiently perpendicular to the running direction, in particular precisely perpendicular, and an axis that is sufficiently parallel to the road surface, in particular precisely parallel. Here, sufficient means that the deviation is less than 5 °. In the tilt movement, the light shielding plate edge preferably moves forward in the case of the vertical light shielding plate of FIG. 7, and the light shielding plate edge preferably moves downward in the case of the horizontal light shielding plate of FIG. In one preferred embodiment, the movement of the shading plate takes place between two final positions. In the final position slid downward or backward, or the final position tilted forward or downward, the projector headlight supports the high beam function. It is also preferred that the shading plate can be moved from time to time to one or more intermediate positions between the final positions.

  Another embodiment is that the lens 58 also scatters the microstructure, light on one or more surfaces of the lens 58, in the region of light and dark boundaries, with other optical functions such as color correction or further contrast reduction. It is characterized by satisfaction depending on the organizational structure to be achieved. To illustrate this, FIG. 6 shows the lens 58 in the following embodiment of the imaging optical system 22. In other words, the imaging optical system has a plurality of local bulges and depressions as a tissue structure 92 that scatters light on the light exit surface 90.

  FIG. 9 shows another embodiment that can be realized both when the light shielding plate 32 is arranged vertically and when it is arranged horizontally. A feature of this embodiment is that the shading plate 32 has bulges and / or depressions and / or further holes 88 in its plane, which are more than the first holes 50 used to widen the light / dark boundary in the peripheral region. Is located away from the light shielding plate edge 34. By this further hole, depression, or bulge, the shielding action of the light shielding plate 32 is locally modified according to the purpose. This gives a specific orientation to a specific light, for example a traffic sign usually in the dark area 30 of the second light distribution pattern 24, but a slight but acceptable and prescribed light intensity, and Illuminate oncoming vehicles with light intensity that does not cause dazzling. These holes, in another embodiment, include optical elements.

Claims (10)

A projector headlight (10) for an automobile, that is, a light shield having at least one light source (12), an optical element (14) collecting light (15) of the light source (12), and a light shielding plate edge (34). It has a plate (32) and an imaging optical system (22). In this case, the optical element (14) converts the collected light (15) into a luminous flux and directs it toward the light shielding plate edge (34). As a result, the light shielding plate A first light distribution pattern divided by the light-shielding plate edge (34) is generated at a position in contact with the edge (34), and this light distribution pattern is generated by the imaging optical system (22). is imaged on the front view of the projector headlamp (10) as 24), in which, the light shielding plate edge (34) is a second light distribution pattern (24), a second light distribution pattern (24) A relatively bright area (28); Comparatively imaged as dark limit (26) between the dark area (30), a projector headlight,
The shading plate (32) has a projection (40) and / or a notch (38) with one open at the shading plate edge (34) and / or the shading plate (32) is delimited by a closed periphery. A plurality of first holes (50) are held in the light shielding plate (32), and these holes are formed from the light shielding plate edge (34) and one fifth of the width (52) of the light shielding plate (32). Are also arranged with a small interval ,
The light shielding plate edge (34) has a central region (42) close to the optical axis (31), and in this central region (42), the light shielding plate (32) is a projection (40) on the light shielding plate edge (34). Neither has an incision (38) with one open, nor does it have a first hole (50) delimited by a closed rim in the shading plate ,
Projector headlight. The imaging optical system (22) is a non-rotationally symmetric lens (58) with respect to the optical axis (31) or a non-rotationally symmetric astigmatism type lens system with respect to the optical axis (31). The projector headlight according to claim 1. The imaging optical system (22) has a different focal point on the optical axis (31) on the plane extending along the light shielding plate edge (34) than in the direction extending across the light shielding plate edge. The projector headlight according to claim 2, wherein the projector headlight is characterized. The light shielding plate edge (34) is on the optical axis (31) of the imaging optical system with respect to one (66) of the focal points (64, 66) on the optical axis (31) of the imaging optical system (22). 4. Projector headlight according to claim 3, characterized in that it is located closer to the other than the other of the focal points (64). In the direction of the optical axis (31), the light shielding plate edge (34) is not far from the imaging optical system (22) with respect to the focal point (66) far from the imaging optical system (22). Projector headlight according to claim 4, characterized in that it is located closer to the focal point (64). The light shielding plate (32) intersects a plane determined by the light shielding plate edge (34) and the optical axis (31) at an angle of 0 ° or more and less than 20 °, and the light shielding plate (32) is reflective. The projector headlight according to claim 1, wherein the projector headlight has a surface. The shading plate (32) has bulges and / or depressions and / or further holes (88) in its plane, which are farther from the shading plate edge (34) than the first hole (50). The projector headlight according to claim 1, wherein the projector headlight is located . The area and / or number of notches (38) and / or protrusions (40) and / or first holes (50) in the average transition line (36) of the light shielding plate edge (34) is determined by the optical axis ( The projector headlight according to any one of claims 1 to 7 , wherein the distance from (31) increases as the distance increases. The imaging optical system (22) is characterized by having a local bulge and / or depression as a tissue structure (92) for scattering light on its light incident surface and / or light exit surface (90). The projector headlight according to any one of claims 1 to 8 . The projector headlight according to any one of claims 1 to 9, wherein the light shielding plate (32) is a movable type .

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