Luminaire unit
By setting a mirror surface and optimizing the position of the emission surface in the light guide of the luminaire unit, the problems of low beam utilization and high cost are solved, and efficient formation of low beam and high beam light distribution patterns and brightness enhancement are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KOITO MFG CO LTD
- Filing Date
- 2021-12-02
- Publication Date
- 2026-05-15
AI Technical Summary
Existing lighting units suffer from reduced beam utilization and insufficient brightness when forming low beam and high beam patterns through a single light guide component, and the large number of light guide components leads to high costs.
The light guide structure includes a first emission surface and a second emission surface. The second emission surface is displaced to the lower side of the first emission surface, and a mirror surface is provided on the connecting surface. The light is reflected by the mirror surface to improve the beam utilization and reduce the number of light guide components.
It achieves the ability to appropriately form low-beam and high-beam light distribution patterns while reducing costs, effectively suppressing light guide melting loss, and improving the uniformity and brightness of light distribution.
Smart Images
Figure CN116601427B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a lamp unit equipped with a projection lens. Background Technology
[0002] Previously, it was known that a lamp unit was configured to project light from a light source through a projection lens onto the front of the unit.
[0003] In Patent Document 1, the structure of such a lamp unit is described as follows: a light guide is disposed between the light source and the projection lens to guide the light emitted from the light source into the projection lens.
[0004] The lighting unit described in Patent Document 1 has the following structure: as its light source, it includes: a first light source for forming a low beam light distribution pattern; and a second light source for forming a high beam light distribution pattern by illuminating simultaneously with the first light source. Furthermore, as its light guide, it includes: a first light guide for guiding light emitted from the first light source; and a second light guide for guiding light emitted from the second light source.
[0005] In the lighting unit described in Patent Document 1, the lower edge shape of the emission surface of the first light guide is used to form a cutoff line for a light distribution pattern for low beams. At this time, a portion of the light from the first light source incident on the first light guide is totally reflected at its lower surface.
[0006] Existing technical documents
[0007] Patent Document 1: Japanese Patent Publication No. 2017-199660
[0008] In such a lighting unit, if the light guide is made of a single component, the number of parts in the lighting unit can be reduced, thereby reducing the cost of the lighting unit.
[0009] At this time, as a light guide, it has: a first emitting surface for emitting light for a low beam light distribution pattern; and a second emitting surface for emitting light for an additional light distribution pattern added to the low beam light distribution pattern when forming a high beam light distribution pattern. Based on the above structure, if the second emitting surface is formed relative to the first emitting surface at a position displaced to the rear of the unit, the lower edge of the first emitting surface can be used to form a cutoff line for the low beam light distribution pattern.
[0010] On the other hand, with this structure, a connecting surface is formed in the light guide that extends from the lower edge of the first emission surface to the upper edge of the second emission surface behind the unit. However, light from the second light source that exits from the second emission surface and reaches the connecting surface is re-intruded into the light guide through this connecting surface, thus reducing the beam utilization relative to the emitted light from the second light source. Furthermore, the brightness of the additional light distribution pattern is reduced, so a light distribution pattern for high beams cannot be formed with the desired luminous intensity distribution. Summary of the Invention
[0011] In light of this, the present invention aims to provide a lighting unit that, in which a projection lens is provided, can appropriately form a low beam light distribution pattern and a high beam light distribution pattern, respectively, while reducing costs by reducing the number of its components.
[0012] This invention achieves the above objective by studying the structure of the light guide disposed between the light source and the projection lens.
[0013] That is, the lamp unit of the present invention is configured to project light from a light source toward the front of the unit via a projection lens, and the lamp unit is characterized in that...
[0014] A light guide is disposed between the light source and the projection lens. The light guide is configured to guide the light emitted from the light source and direct the emitted light into the projection lens.
[0015] The light source comprises: a first light source for forming a low-beam light distribution pattern; and a second light source for forming a high-beam light distribution pattern by simultaneously illuminating the first light source.
[0016] The light guide includes: a first emission surface for emitting light for the low beam light distribution pattern; and a second emission surface for emitting light for an additional light distribution pattern added to the low beam light distribution pattern when forming the high beam light distribution pattern.
[0017] The second injection surface is formed below the first injection surface at a position displaced relative to the first injection surface toward the rear of the unit.
[0018] The light guide has a connecting surface that extends from the lower edge of the first emission surface toward the rear of the unit to the upper edge of the second emission surface.
[0019] A mirrored surface is provided on the connecting surface.
[0020] The specific configuration and surface shape of the aforementioned "connecting surface" are not particularly limited as long as it extends from the lower edge of the first injection surface to the rear of the unit and to the upper edge of the second injection surface.
[0021] The aforementioned "mirror surface" can be set on the entire area of the connecting surface, or it can be set on only a part of its area.
[0022] The specific structure of the aforementioned "mirror surface" is not particularly limited. For example, it can be a mirror surface formed by vacuum evaporation of aluminum or by pasting aluminum foil.
[0023] The lighting unit of the present invention is a structure that illuminates light from a light source in front of the unit through a projection lens. However, a light guide is disposed between the light source and the projection lens. The light guide is configured to guide the light emitted from the light source and cause it to enter the projection lens. Therefore, the incident light to the projection lens is controlled by the light guide, thereby forming a light distribution pattern of the desired shape.
[0024] Specifically, the light source comprises: a first light source for forming a low beam light distribution pattern; and a second light source for forming a high beam light distribution pattern by illuminating simultaneously with the first light source. Furthermore, the light guide comprises: a first emitting surface for emitting light for the low beam light distribution pattern; and a second emitting surface for emitting light for an additional light distribution pattern added to the low beam light distribution pattern when forming the high beam light distribution pattern, thus enabling selective formation of both the low beam light distribution pattern and the high beam light distribution pattern.
[0025] At this time, the second emission surface of the light guide is displaced on the side below the first emission surface relative to the rear side of the unit, so that the cutoff line of the light distribution pattern for low beam can be formed through the shape of the lower edge of the first emission surface.
[0026] Based on this, the light guide has a connecting surface that extends from the lower edge of the first emission surface to the rear of the unit and to the upper edge of the second emission surface. A mirror surface is provided on the connecting surface, so the following effects can be achieved.
[0027] That is, if the light from the second light source that is emitted from the second emission surface and reaches the connecting surface is incident on the light guide again from the connecting surface, the beam utilization rate relative to the emitted light from the second light source is reduced, thereby reducing the brightness of the additional light distribution pattern, and thus the light distribution pattern for high beam cannot be formed with the desired luminous intensity distribution.
[0028] However, in this invention, a mirror surface is provided on the connecting surface of the light guide, so as to prevent or suppress light from the second light source that has been emitted from the second emission surface and reached the connecting surface from the connecting surface from re-entering the light guide, thereby enabling the formation of a high beam light distribution pattern with a desired light intensity distribution.
[0029] Moreover, since the light guide is made of a single component, the aforementioned effects can be achieved while reducing costs by reducing the number of components in the lamp unit.
[0030] Therefore, according to the present invention, in a lamp unit equipped with a projection lens, cost reduction is achieved by reducing the number of its components, and a light distribution pattern for low beam and a light distribution pattern for high beam can be appropriately formed respectively.
[0031] In the above structure, if the area near the rear focal point of the projection lens is configured as a light transmission part, which is the connecting surface of the light guide, the following effects can be obtained.
[0032] That is, in a light guide, the area near the focal point on the rear side of the projection lens can sometimes become very hot due to the focused sunlight or other light entering through the projection lens from outside the lamp unit. In this case, depending on the material of the light guide, it is prone to melting. If a mirrored surface is provided throughout the entire area of the light guide's connection surface, heat is more likely to remain near the focal point of the light guide, making melting more likely.
[0033] In contrast, if the area near the rear focal point of the projection lens in the connecting surface of the light guide is configured as a light transmission part, then a portion of the sunlight and other light incident on the area near the focal point of the light guide can be emitted into the lower space without being reflected by the connecting surface. This makes it difficult for heat to remain in the area near the focal point, thus effectively suppressing the occurrence of melting.
[0034] In the above structure, if the area near the front edge of the connecting surface of the light guide is configured as a light transmission part, the following effects can be achieved.
[0035] That is, light emitted from the second emitting surface and reaching the region near the front edge of the connecting surface is re-intruded into the light guide through the light transmission portion in the region near the front edge, and is emitted towards the front of the unit from the region near the lower edge of the first emitting surface. Furthermore, this emitted light is projected towards the front of the unit via a projection lens, forming an additional light distribution pattern in which its lower edge partially overlaps with the region near the cutoff line of the low beam light distribution pattern. Therefore, the high beam light distribution pattern can be formed as a substantially uniform light distribution pattern in which the low beam light distribution pattern and the additional light distribution pattern are smoothly connected.
[0036] In the above structure, if the front-to-back width of the area near the front edge is set to a value of 1 / 3 or less relative to the front-to-back width of the connecting surface, a more preferred light distribution pattern for high beams can be formed.
[0037] In the above structure, in the case where the light guide is made of a resin component, the area near its focal point is prone to melting due to sunlight or other light incident from outside the lamp unit via the projection lens. Therefore, it is particularly effective to make the area near the rear focal point of the projection lens in the connecting surface into a light transmission part.
[0038] In the above structure, furthermore, based on the structure having multiple first light sources, if the light guide has a structure having multiple incident parts for incident on each of the multiple first light sources, then a light distribution pattern for low beam can be easily formed in a desired shape. Attached Figure Description
[0039] Figure 1 This is a side sectional view showing a vehicle lamp equipped with a lamp unit according to one embodiment of the present invention.
[0040] Figure 2 yes Figure 1 View from direction II.
[0041] Figure 3 This is a side sectional view of the aforementioned lighting unit, representing a single component.
[0042] Figure 4 yes Figure 3 Sectional view along line IV-IV.
[0043] Figure 5 yes Figure 3 VV-line sectional view.
[0044] Figure 6 yes Figure 3 Sectional view along line VI-VI.
[0045] Figure 7 This is an exploded perspective view of the aforementioned lighting unit as seen from a diagonal front.
[0046] Figure 8 This is an exploded perspective view of the aforementioned lighting unit, viewed from a slightly rearward angle.
[0047] Figure 9 yes Figure 3 Detailed diagram of the main parts.
[0048] Figure 10 yes Figure 9 Detailed diagram of the X-section.
[0049] Figure 11 (a) is Figure 10 The sectional view along line XIa-XIa, (b), (c) and (d) are the same as (a) as the first, second and third variations of the above-described embodiments.
[0050] Figure 12 It is a diagram showing the light distribution pattern formed by the illumination light from the aforementioned luminaire unit.
[0051] Figure 13 This represents the second variation of the above. Figure 9 Same diagram.
[0052] Figure 14 yes Figure 13 Detailed diagram of part XIV.
[0053] Figure 15 This indicates the function of the second variation mentioned above. Figure 12 Same diagram. Detailed Implementation
[0054] The embodiments of the present invention will now be described with reference to the accompanying drawings.
[0055] Figure 1 This is a side sectional view showing a vehicle lamp 100 equipped with a lamp unit 10 according to one embodiment of the present invention. Furthermore, Figure 2 yes Figure 1 View from direction II.
[0056] In these diagrams, the direction represented by X is "front of the element," the direction represented by Y is the "left direction" (or "right direction" in the main view of the element) orthogonal to "front of the element," and the direction represented by Z is the "up direction." The same applies to other diagrams.
[0057] The vehicle lamp 100 is a headlight installed at the front end of the vehicle, and its structure is as follows: In the lamp housing formed by the lamp body 102 and the light-transmitting cover 104, the lamp unit 10 is housed in a state in which its optical axis is adjusted in a manner that is approximately consistent with the front-rear direction (i.e. the front-rear direction of the unit) with the front-rear direction of the vehicle.
[0058] The luminaire unit 10 is a projection type luminaire unit, and its structure is as follows: by directing light from the light source 20 through the projection lens 30 to illuminate the front of the unit, a low beam light distribution pattern and a high beam light distribution pattern can be formed (this will be explained later).
[0059] The projection lens 30 has an optical axis Ax extending in the front-rear direction of the unit, and forms the above-mentioned light distribution pattern by reversing the projection image formed on its rear focal plane.
[0060] A light guide 40 is disposed between the projection lens 30 and the light source 20 disposed behind it, configured to guide the light emitted from the light source 20 into the projection lens 30. The aforementioned projection image is formed in the light guide 40.
[0061] Figure 3 This is a side sectional view showing the lighting unit 10 as a single piece. Furthermore, Figure 4 yes Figure 3 Sectional view along line IV-IV, Figure 5 yes Figure 3 VV-line sectional view, Figure 6 yes Figure 3A sectional view along line VI-VI. Furthermore... Figure 7 This is an exploded perspective view of the lighting unit 10 as viewed from a diagonal front. Figure 8 This is an exploded perspective view of the lighting unit 10 viewed from the rear.
[0062] As shown in these figures, the projection lens 30 is a biconvex aspherical lens with an outer peripheral flange 32, and is made of colorless and transparent acrylic resin. The projection lens 30 is supported by a lens holder 50 at its outer peripheral flange 32.
[0063] The lens support 50 is a cylindrical member extending in the front-back direction of the unit, made of opaque polycarbonate resin, with an annular lens support portion 52 formed at its front end.
[0064] The projection lens 30 is fixed to the lens support 50 by laser welding while its outer peripheral flange 32 is pressed against the lens support 52 of the lens holder 50 from the front side of the unit.
[0065] At this time, by engaging the positioning holes 32a and positioning grooves 32b formed on the upper and lower parts of the outer peripheral flange portion 32 of the projection lens 30 with the upper and lower pair of positioning pins 52a and 52b formed on the lens support portion 52 of the lens holder 50, the projection lens 30 is positioned relative to the lens holder 50 in a direction orthogonal to the front-back direction of the unit.
[0066] The light source 20 consists of four light-emitting elements 22A, 22B, 22C, and 22D mounted on a common substrate 24. The four light-emitting elements 22A to 22D are all white light-emitting diodes with a rectangular light-emitting surface that is laterally elongated, and are arranged with their light-emitting surfaces facing the front of the unit.
[0067] Three of the four light-emitting elements 22A to 22D, namely 22A to 22C, are lit when forming the low beam light distribution pattern, and the remaining light-emitting element 22D is lit additionally when forming the high beam light distribution pattern.
[0068] Three light-emitting elements 22A to 22C are positioned directly above the optical axis Ax of the projection lens 30 and at a certain distance to the left and right, while light-emitting element 22D is positioned directly below the optical axis Ax.
[0069] The substrate 24 is supported by the lens holder 50 in a state in which it is configured to extend along a vertical plane orthogonal to the optical axis Ax of the projection lens 30 (this will be explained later).
[0070] A connector 26 is mounted at the lower center of the front surface of the substrate 24. The connector 26 is electrically connected to four light-emitting elements 22A to 22D via a conductive pattern (not shown). Power is supplied to the four light-emitting elements 22A to 22D by mounting a power-side connector (not shown) on the connector 26.
[0071] The light guide 40 is made of colorless and transparent polycarbonate resin components.
[0072] The light guide 40 includes: a first emission surface 42A for emitting light for a low beam light distribution pattern; and a second emission surface 42B for emitting light for an additional light distribution pattern added to the low beam light distribution pattern when forming a high beam light distribution pattern.
[0073] The first emission surface 42A is located on the upper part of the front surface of the light guide 40, and is formed to extend along the rear focal plane of the projection lens 30. For example... Figure 7 As shown, the first injection surface 42A has a generally rectangular shape with chamfered upper corners on both sides. Furthermore, as... Figure 2 , Figure 3 As shown, the lower edge 42Aa of the first emission surface 42A is formed near the rear focal point F of the projection lens 30 and extends horizontally with different heights on the left and right sides.
[0074] The second emission surface 42B is located at the lower part of the front surface of the light guide 40, at a position a certain distance away from the rear focal plane of the projection lens 30 on the rear side of the unit, and is formed to extend along a plane that is slightly inclined backward relative to a vertical plane orthogonal to the optical axis Ax of the projection lens 30. The second emission surface 42B is located directly below the optical axis Ax and has a generally laterally elongated elliptical shape that is lacking in the upper part.
[0075] The light guide 40 includes a block portion 42 that extends rearward toward the unit while generally maintaining the external shape of the first emission surface 42A. The lower surface of this block portion 42 is formed into a connecting surface 42C that extends horizontally from the lower edge 42Aa of the first emission surface 42A toward the upper edge 42Ba of the second emission surface 42B. Furthermore, a mirror portion 42C1 (described later) is provided on this connecting surface 42C.
[0076] Furthermore, the light guide 40 includes four incident portions 44A, 44B, 44C, and 44D for incidenting emitted light from each of the four light-emitting elements 22A, 22B, 22C, and 22D. Three of the incident portions 44A to 44C are configured to be located in front of each of the three light-emitting elements 22A to 22C and behind the block portion 42. The remaining incident portion 44D is configured to be located in front of the light-emitting element 22D and behind the second emission surface 42B.
[0077] The three incident portions 44A to 44C are configured such that, after light emitted from each of the three light-emitting elements 22A to 22C is incident, it is either directly reflected or totally reflected and then guided into the block portion 42. The block portion 42 is configured to guide the incident light from the three incident portions 44A to 44C to the first emission surface 42A. At this time, the light reaching the connecting surface 42C is totally reflected at the connecting surface 42C and then guided to the first emission surface 42A. The incident portion 44D is configured such that, after light emitted from the light-emitting element 22D is incident, it is either directly reflected or totally reflected and then guided to the second emission surface 42B.
[0078] like Figure 1 As shown, light from the light-emitting element 22B, incident on the light guide 40 from the incident portion 44B located directly above the optical axis Ax, is emitted from the first emission surface 42A toward the projection lens 30, illuminating the front of the unit as generally downward light from the projection lens 30. The same applies to light from the light-emitting elements 22A and 22C incident on the light guide 40 from the incident portions 44A and 44C located on the right and left sides. Conversely, light from the light-emitting element 22D incident on the light guide 40 from the incident portion 44D is emitted from the second emission surface 42B toward the projection lens 30, illuminating the front of the unit as generally upward light from the projection lens 30.
[0079] like Figure 7 , Figure 8 As shown, in the light guide 40, an outer peripheral flange 46 extending along a vertical plane orthogonal to the optical axis Ax is formed on the upper part and the left and right sides of the rear end portion of the block portion 42. Furthermore, when the light guide 40 is housed within the internal space of the lens holder 50, its outer peripheral flange 46 is supported by the lens holder 50.
[0080] A light guide support portion 54 is formed in the lens holder 50, extending along the outer peripheral flange portion 46 of the light guide 40.
[0081] Furthermore, the light guide 40 is fixed to the lens holder 50 by laser welding while its outer peripheral flange 46 presses against the rear surface of the light guide support portion 54 of the lens holder 50 from the rear side of the unit.
[0082] At this time, by engaging the pair of left and right positioning holes 46a formed on the outer peripheral flange portion 46 of the light guide 40 with the pair of left and right positioning pins 54a formed on the light guide support portion 54 of the lens bracket 50, the light guide 40 is positioned relative to the lens bracket 50 in a direction orthogonal to the front-back direction of the unit.
[0083] The lighting unit 10 includes a metal (e.g., aluminum) heat sink 70 for dissipating heat generated by the four light-emitting elements 22A, 22B, 22C, and 22D.
[0084] The heat sink 70 includes a main body 72 extending along a vertical plane orthogonal to the optical axis Ax of the projection lens 30, and a plurality of heat sink fins 74 extending from the main body 72 toward the rear of the unit along the vertical plane. Furthermore, the heat sink 70 is supported together with the substrate 24 by the lens bracket 50 in a state where the front surface of its main body 72 is in contact with the rear surface of the substrate 24.
[0085] The lens holder 50 supports the substrate 24 and the heat sink 70 by mechanical fastening. Specifically, the substrate 24 and the heat sink 70 are fixed to the lens holder 50 at their left and right locations by screws.
[0086] A pair of screw fastening protrusions 56 are formed on the left and right sides of the lens holder 50, and a pair of screw through holes 24a and 72a are formed on the main body 72 of the substrate 24 and the heat sink 70, respectively, for the screws 76 used for common fastening to pass through.
[0087] In the lens holder 50, stepped positioning pins 58 extending rearward toward the unit are formed at three locations: the upper central end and the lower left and right ends. Furthermore, in the substrate 24, positioning holes 24b are formed at three locations: the upper central end and the lower left and right ends. The small-diameter front end 58a of each stepped positioning pin 58 is inserted into the positioning hole 24b of the substrate 24, and the substrate 24 abuts against the front flat end 58b of each stepped positioning pin 58, thereby positioning the substrate 24 relative to the lens holder 50 in the front-rear direction and in the direction orthogonal to it.
[0088] A reinforcing rib 60 is formed on the upper wall of the lens holder 50, and the reinforcing rib 60 is formed in a generally U-shape so as to be connected to the base end of the step-shaped positioning pin 58.
[0089] Furthermore, a pair of left and right positioning portions 62 are formed on the lens bracket 50 for positioning the heat sink 70 in a direction orthogonal to the front-back direction of the unit. These positioning portions 62 are formed to extend toward the rear of the unit in a shape that wraps around the upper and lower end faces of the main body 72 near the left and right end faces of the heat sink 70.
[0090] Furthermore, L-shaped cutouts 62a are formed at the upper and lower ends of the pair of left and right positioning portions 62. Thus, when the substrate 24 and the heat sink 70 are fixed to the lens bracket 50, the substrate 24 abuts against the cutouts 62a at the four locations to position its unit in the front-back direction.
[0091] Figure 9 yes Figure 3 Detailed diagrams of the main components. In addition... Figure 10 yes Figure 9 Detailed diagram of the X-section. Furthermore... Figure 11 (a) is Figure 10 Sectional view along line XIa-XIa.
[0092] like Figure 11 As shown in (a), a mirror surface 42C1 is provided on the lower surface of the connecting surface 42C of the constituent block portion 42 in the light guide 40 and throughout its entire area. This mirror surface 42C1 is formed by vacuum evaporation of aluminum or the like on the surface of the connecting surface 42C.
[0093] like Figure 9 , Figure 10 As shown, most of the light from the light-emitting element 22B that enters the light guide 40 from the incident portion 44B located directly above the optical axis Ax directly reaches the first emission surface 42A and is emitted towards the projection lens 30 as light oriented obliquely downward from the first emission surface 42A. However, a portion of the light reaches the first emission surface 42A after total internal reflection at the connecting surface 42C and is emitted towards the projection lens 30 as light oriented obliquely upward from the first emission surface 42A.
[0094] On the other hand, the light from the light-emitting element 22D that enters the light guide 40 from the incident portion 44D, after exiting from the second exit surface 42B towards the projection lens 30, most of the light directly reaches the projection lens 30, but a portion of the light reaches the connecting surface 42C. At this time, assuming that the connecting surface 42C does not have a mirror surface 42C1, as shown by the double-dotted line in the figure, the light reaching the connecting surface 42C, after re-entering the block portion 42 from the connecting surface 42C, exits from the first exit surface 42A as upward-facing light in a direction away from the projection lens 30. However, in reality, since the connecting surface 42C1 is provided throughout its entire area, the light reaching the connecting surface 42C is reflected by the mirror surface 42C1 and reaches the projection lens 30 as downward-facing light.
[0095] Figure 12 It is a perspective view showing the light distribution pattern formed on an imaginary vertical screen positioned 25m in front of the vehicle by light illuminating from the lamp unit 10 of the vehicle lamp 100 towards the front of the unit. Figure 12 (a) is a diagram showing the light distribution pattern (PL) for low beam. Figure 12(b) is a diagram representing the high beam pattern PH1.
[0096] like Figure 12 As shown in (a), the low beam distribution pattern PL is a left-aligned low beam distribution pattern with cutoff lines CL1 and CL2 at its upper edge, which have different heights on the left and right sides. These cutoff lines CL1 and CL2 extend horizontally with different heights on the left and right sides, bounded by the VV line (which passes through the vanishing point of HV in the vertical direction of the luminaire). The portion on the opposite lane side, closer to the right of the VV line, forms the lower cutoff line CL1, and the portion on the lane side, closer to the left of the VV line, forms the upper cutoff line CL2, which rises from the lower cutoff line CL1 via an inclined section. In the low beam distribution pattern PL, the inflection point E, which is the intersection of the lower cutoff line CL1 and the VV line, is located approximately 0.5 to 0.6° below HV.
[0097] The low beam uses a light distribution pattern PL, which is formed into a composite light distribution pattern of three light distribution patterns PA, PB, and PC.
[0098] Each light distribution pattern PA, PB, and PC is a reverse projection image of a projection image formed on the first emission surface 42A of the light guide 40 using the emitted light from each of the light-emitting elements 22A, 22B, and 22C. Furthermore, the near beam light distribution pattern PL, which is formed as a composite light distribution pattern of these patterns, is formed with a shape that approximately corresponds to the shape of the first emission surface 42A of the light guide 40.
[0099] At this time, the light guide 40 is configured such that its first emission surface 42A is located on the rear focal surface of the projection lens 30, so the near beam light distribution pattern PL clearly forms the cutoff lines CL1 and CL2.
[0100] like Figure 12 As shown in (b), the high beam pattern PH1 is supplemented with an additional beam pattern PD1 that extends above the cutoff lines CL1 and CL2, relative to the low beam pattern PL.
[0101] The additional light distribution pattern PD1 is formed as a reversed projection image of the projection image formed on the rear focal plane of the projection lens 30 using light emitted from the light-emitting element 22D emitted from the second emission surface 42B of the light guide 40. At this time, the upper position of the projection image is defined by the lower edge 42Aa of the first emission surface 42A, so the lower position of the additional light distribution pattern PD1 is defined by the cutoff lines CL1 and CL2. Therefore, the high beam light distribution pattern PH1 becomes a pattern in which the low beam light distribution pattern PL and the additional light distribution pattern PD1 are seamlessly connected.
[0102] Next, the function of this embodiment will be explained.
[0103] The lighting unit 10 of this embodiment is a structure that illuminates the light from the light source 20 in front of the unit through the projection lens 30. However, it is configured such that a light guide 40 is disposed between the light source 20 and the projection lens 30 to guide the light emitted from the light source 20 into the projection lens 30. Therefore, the incident light into the projection lens 30 is controlled by the light guide 40, thereby forming a light distribution pattern of the desired shape.
[0104] Specifically, the light source 20 includes: three light-emitting elements 22A, 22B, and 22C (first light source) for forming a low beam light distribution pattern PL; and a light-emitting element 22D (second light source) for forming a high beam light distribution pattern PH1 by simultaneously illuminating these light-emitting elements 22A to 22C. In addition, the light guide 40 includes: a first emission surface 42A for emitting light for the low beam light distribution pattern PL; and a second emission surface 42B for emitting light for an additional light distribution pattern PD1 added to the low beam light distribution pattern PL when forming the high beam light distribution pattern PH1. Therefore, it is possible to selectively form the low beam light distribution pattern PL and the high beam light distribution pattern PH1.
[0105] At this time, because the second emission surface 42B of the light guide 40 is displaced to the rear side of the unit relative to the first emission surface 42A on the lower side of the first emission surface 42A, the cutoff lines CL1 and CL2 of the low beam light distribution pattern PL can be formed by utilizing the shape of the lower edge 42Aa of the first emission surface 42A.
[0106] Based on this, the light guide 40 has a connecting surface 42C extending from the lower edge 42Aa of the first emission surface 42A to the rear of the unit and to the upper edge 42Ba of the second emission surface 42B. Since a mirror surface 42C1 is provided on the connecting surface 42C, the following effects can be achieved.
[0107] That is, if the light emitted from the light-emitting element 22D that is emitted from the second emission surface 42B and reaches the connecting surface 42C is re-intruded into the light guide 40 from the connecting surface 42C, the beam utilization rate relative to the emitted light from the light-emitting element 22D is reduced, thereby reducing the brightness of the additional light distribution pattern PD1. Therefore, the high beam light distribution pattern PH1 cannot be formed with the desired light intensity distribution.
[0108] However, in this embodiment, a mirrored surface 42C1 is provided over the entire area of the connecting surface 42C of the light guide 40. This prevents light emitted from the light-emitting element 22D that has exited from the second emitting surface 42B and reached the connecting surface 42C from re-entering the light guide 40 through the connecting surface 42C. Furthermore, by reflecting the light from the light-emitting element 22D that reaches the connecting surface 42C through the mirrored surface 42C1, it can be used as light to form an additional light distribution pattern PD1, thereby enabling the formation of a high-beam light distribution pattern PH1 with a desired luminous intensity distribution.
[0109] Moreover, since the light guide 40 is composed of a single component, the aforementioned effects can be achieved by reducing the cost through the reduction of the number of components in the lamp unit 10.
[0110] Therefore, according to this embodiment, in the lamp unit 10 equipped with the projection lens 30, cost reduction is achieved by reducing the number of its components, and a low beam light distribution pattern PL and a high beam light distribution pattern PH1 can be appropriately formed respectively.
[0111] Furthermore, in the lamp unit 10 of this embodiment, the first light source for forming the low beam light distribution pattern PL includes three light-emitting elements 22A, 22B, and 22C, and the light guide 40 includes three incident portions 44A to 44C for incident light emitted from each of the three light-emitting elements 22A, 22B, and 22C. Therefore, the low beam light distribution pattern PL can be formed clearly in the desired shape.
[0112] In the above embodiments, the light guide 40 is described as being made of a colorless and transparent polycarbonate resin component, but it may also be made of a colorless and transparent acrylic resin component or a colorless and transparent glass component, etc.
[0113] In the above embodiment, the light guide 40 is described as having a mirror surface 42C1 provided throughout the entire area of its connecting surface 42C, but it may also have a structure with areas where the mirror surface 42C1 is not provided.
[0114] In the above embodiment, it is described that all four light-emitting elements 22A to 22D have a rectangular light-emitting surface with a horizontal length. However, they may also have a structure with other shapes (such as a square or a rectangle with a vertical length).
[0115] In the above embodiment, the first light source is described as consisting of three light-emitting elements 22A, 22B, and 22C, and the second light source is described as consisting of one light-emitting element 22D. However, the number of the first and second light sources can also be set to a number different from that in the above embodiment.
[0116] Next, variations of the above-described embodiments will be described.
[0117] First, a first variation of the above-described embodiment will be explained.
[0118] Figure 11 (b) represents the essential part of the lighting unit in this variation. Figure 11 The same diagram as (a).
[0119] like Figure 11 As shown in (b), the basic structure of this modified example is the same as that of the above embodiment, but a part of the structure of the light guide 140 is different from that of the above embodiment.
[0120] That is, the light guide 140 in this modified example also has a structure in which a mirror surface 142C1 is provided on the connecting surface 142C of the lower surface of the block portion 142. However, the difference from the above embodiment is that a part of the connecting surface 142C is configured as a light transmission portion 142C2.
[0121] Specifically, in the connecting surface 142C, located at the projection lens 30 (refer to...) Figure 1 The area near the rear focal point F of the light transmission section is configured as a transparent surface light transmission section 142C2 without a mirror surface 142C1 (i.e. without vacuum evaporation of aluminum, etc.).
[0122] The light-transmitting section 142C2 is configured as a semi-circular region with radius R centered on the rear focal point F of the projection lens 30 when viewed from above. In this case, the value of radius R is set to less than 1 / 3 (for example, about 1 / 10 to 1 / 4) of the front-to-back width D of the connecting surface 142C (i.e., the width from the lower edge 142Aa of the first emission surface 142A to the upper edge 142Ba of the second emission surface 142B). Specifically, it is preferable to set this radius R to approximately 4 to 10 mm.
[0123] By adopting the structure of this modified example, the following effects can be achieved.
[0124] That is, in the block portion 142 of the light guide 140, the area near the focal point F on the rear side of the projection lens 30 sometimes becomes hot due to the focusing of sunlight and other light incident from outside the lamp unit via the projection lens 30.
[0125] In this modified example, the light guide 140 is made of resin, which makes it prone to melting due to the focusing effect of sunlight, etc. In this case, if it is assumed that a mirror surface 142C is provided in the entire area of the connecting surface 142C of the light guide 140, heat is easily trapped near the focal point of the light guide 140, and melting is more likely to occur.
[0126] However, in this modified example, since the area near the rear focal point F of the projection lens 30 in the connecting surface 142C of the light guide 140 is configured as a light transmission section 142C2, a portion of sunlight and other light incident on the area near the focal point of the block portion 142 of the light guide 140 is prevented from being reflected by the connecting surface 142C and emitted into the downward space. Furthermore, this prevents heat from accumulating near the focal point, thus effectively suppressing melting.
[0127] In the first modified example described above, the light transmission section 142C2 is set as a semi-circular region, but it can also be set as a region with a shape other than that.
[0128] Next, a second variation of the above-described embodiment will be described.
[0129] Figure 13 This indicates that the lighting unit 210 in this modified example is connected to... Figure 9 The same diagram, Figure 14 yes Figure 13 Detailed diagram of section XIV. Furthermore... Figure 11 (c) is Figure 14 XIc-XIc line sectional view (i.e., with Figure 11 (a) is the same as the figure.
[0130] like Figure 13 , Figure 14 As shown, the basic structure of this modified example is the same as that of the above embodiment, but a part of the structure of the light guide 240 is different from that of the above embodiment.
[0131] That is, the light guide 240 in this modified example also has a structure in which a transparent mirror surface 242C1 is provided on the connecting surface 242C of the lower surface constituting its block portion 242. However, the difference from the above embodiment is that the area near the front edge of the connecting surface 242C is configured as a light transmission portion 242C2.
[0132] Specifically, such as Figure 11 As shown in (c), the strip-shaped region of the connecting surface 242C with a certain front-to-back width from the lower edge 242Aa of the first emission surface 242A is configured as a transparent light-transmitting part 242C2 without a mirror surface 242C1 (i.e., without vacuum evaporation of aluminum, etc.).
[0133] The front-to-back width D1 of the light-transmitting section 242C2 is set to less than 1 / 3 (for example, about 1 / 10 to 1 / 4) relative to the front-to-back width D of the connecting surface 242C (i.e., the width from the lower edge 242Aa of the first emission surface 242A to the upper edge 242Ba of the second emission surface 242B). In this case, the specific value of the front-to-back width D1 is preferably set to a value of about 4 to 10 mm.
[0134] Figure 15 This refers to the light distribution pattern formed by the illumination light from the luminaire unit 210 of this modification. Figure 12 Same diagram.
[0135] Figure 15 The low beam distribution pattern PL shown in (a) is the same as in the above embodiment, but... Figure 15 The high beam pattern PH2 shown in (b) is different from that in the above embodiment.
[0136] That is, the high beam light distribution pattern PH2 is supplemented with an additional light distribution pattern PD2 relative to the low beam light distribution pattern PL. However, the additional light distribution pattern PD2 is formed in a state where its lower edge PD2a partially overlaps with the area near the cutoff lines CL1 and CL2 in the low beam light distribution pattern PL.
[0137] This is because the light emitted from the second emission surface 242B of the light guide 240 and reaching the area near the front edge of the connecting surface 242C is again incident on the light guide 240 from the light transmission portion 242C2 in the area near the front edge, and is emitted from the area near the lower edge of its first emission surface 242A toward the front of the unit, thereby slightly extending the projected image on the rear focal plane of the projection lens 30 upward.
[0138] By adopting the structure of this modified example, the following effects can be achieved.
[0139] In the lamp unit 210 of this modified example, the additional light distribution pattern PD2 can be formed in a state where its lower edge PD2a partially overlaps with the area near the cutoff lines CL1 and CL2 in the low beam light distribution pattern PL. Therefore, the high beam light distribution pattern PH2 can be formed into a generally uniform light distribution pattern in which the low beam light distribution pattern PL and the additional light distribution pattern PD2 are smoothly connected.
[0140] At this time, since the front-to-back width D2 of the light transmission portion 242C2 is set to a value of 1 / 3 or less relative to the front-to-back width D of the connecting surface 242C, the light guide 240 of this modified example can form a high beam light distribution pattern PH2 with a more preferred light intensity distribution.
[0141] Furthermore, in this modified example, since the connecting surface 242C of the light guide 240 is also configured as a light transmission portion 242C2 in the area near the rear focal point F of the projection lens 30, a portion of sunlight and other light incident on the area near the focal point of the block portion 242 of the light guide 240 can be emitted downward into the space without reflection at the connecting surface 242C. Moreover, this makes it difficult for heat to remain near the focal point, thus effectively suppressing the occurrence of melting.
[0142] In the second modified example described above, it is explained that the light transmission portion 242C2 of the connecting surface 242C is configured as a strip-shaped region with a certain front-to-back width D1 starting from the lower edge 242Aa of the first emission surface 242A. However, in addition to this, for example, the following structure may also be adopted: configured as a strip-shaped region with a front-to-back width that varies according to the left-to-right position of the light transmission portion 242C2, or configured as a strip-shaped region with a certain front-to-back width, with the position slightly away from the lower edge 242Aa of the first emission surface 242A towards the rear of the unit as the front edge.
[0143] Next, a third variation of the above-described embodiment will be described.
[0144] Figure 11 (d) represents the essential part of the lighting unit in this variation. Figure 11 The same diagram as (a).
[0145] like Figure 11 As shown in (d), the basic structure of this modified example is the same as that of the second modified example described above, but a part of the structure of the light transmission part 342C2 is different from that of the second modified example described above.
[0146] That is, in this modified example, the area near the front edge of the connecting surface 342C of the lower surface of the block portion 342 of the light guide 340 is also configured as a light transmission portion 342C2. However, the difference from the second modified example is that the light transmission portion 342C2 is not made of a transparent surface but is made of a semi-transparent surface.
[0147] In this modified example, the light-transmitting section 342C2 is designed as a strip-shaped region with the same shape as the light-transmitting section 242C2 in the second modified example, but with a structure in which aluminum is partially vapor-deposited in the strip-shaped region. Thus, the light-transmitting section 342C2 is configured to reflect a certain proportion of the light reaching the connecting surface 342C instead of transmitting it all.
[0148] Specifically, the reflectivity of the mirror portion 342C1 is set to a value of 90% or more, while the reflectivity of the light-transmitting portion 342C2 is set to a value of 50% or less (for example, a value of about 30 to 40%).
[0149] By adopting the structure of this modified example, the following effects can be achieved.
[0150] That is, the additional light distribution pattern formed by the illumination light from the luminaire unit of this modification is relative to... Figure 15 The supplementary light distribution pattern PD2 shown has a slightly reduced brightness in the area near the cutoff lines CL1 and CL2 at its lower edge PD2a, but a correspondingly increased brightness in the area near the cutoff lines CL1 and CL2. Therefore, as a light distribution pattern for high beams, it can maintain a generally uniform light distribution pattern that is smoothly connected to the low beam light distribution pattern PL, and the supplementary light distribution pattern, while providing superior distance visibility compared to the high beam light distribution pattern PH2.
[0151] Furthermore, the numerical values used as specifications in the above embodiments and their variations are just one example, and of course they can be appropriately set to different values.
[0152] Furthermore, the present invention is not limited to the structures described in the above embodiments and their variations, and various other modified structures may also be used.
[0153] This international application claims priority based on Japanese Patent Application No. 2020-207632, filed on December 15, 2020, the entire contents of which are incorporated herein by reference.
[0154] The above description of specific embodiments of the present invention is for illustrative purposes only. It is not intended to be exhaustive or to limit the invention to the methods described herein. It will be apparent to those skilled in the art that various modifications and alterations can be made based on the above description.
[0155] Explanation of reference numerals in the attached figures
[0156] 10, 210 Lighting Units
[0157] 20 Light Sources
[0158] 22A, 22B, and 22C light-emitting elements (first light source)
[0159] 22D light-emitting element (second light source)
[0160] 24 substrates
[0161] 24a and 72a screw through holes
[0162] 24b, 32a, 46a positioning holes
[0163] 26 connectors
[0164] 30 projection lens
[0165] 32. Outer peripheral flange
[0166] 32b positioning slot
[0167] 40, 140, 240, 340 light guides
[0168] Blocks 42, 142, 242, and 342
[0169] 42A, 142A, 242A First Ejection Surface
[0170] The lower edge of 42Aa, 142Aa, and 242Aa
[0171] 42B and 142B second injection surfaces
[0172] The upper edge of 42Ba and 142Ba
[0173] 42C, 142C, 242C, 342C connection surfaces
[0174] 42C1, 142C1, 242C1, 342C1 mirrored surfaces
[0175] 44A, 44B, 44C, 44D Entrance Sections
[0176] 46. Outer peripheral flange
[0177] 50 Lens Holder
[0178] 52 Lens support section
[0179] 52a, 52b, 54a locating pins
[0180] 54 Light guide support
[0181] 56. Screw fastening protrusion
[0182] 58. Locating pin with step
[0183] 58a Small diameter front end
[0184] 58b Front end planar section
[0185] 60 Reinforcing Ribs
[0186] 62 Positioning Department
[0187] 62a Incision site
[0188] 70 Radiator
[0189] 72 Main body
[0190] 74 Heatsink
[0191] 76 screws
[0192] 100 Vehicle lights
[0193] 102 Lamp Body
[0194] 104 Light-transmitting cover
[0195] 142C2, 242C2, 342C2 light transmission section
[0196] Ax optical axis
[0197] CL1 lower segment cutoff line
[0198] CL2 upper segment cutoff line
[0199] D Front and rear width of the connecting surface
[0200] D1 Front and rear width of the light transmission section
[0201] E Inflection Point
[0202] F Rear Focus
[0203] PA, PB, PC photometric patterns
[0204] Additional light distribution patterns for PD1 and PD2
[0205] PD2a lower edge
[0206] PH1 and PH2 high beam light distribution patterns
[0207] PL low beam beam pattern
[0208] R is the radius of the light-transmitting part.
Claims
1. A lighting unit configured to project light from a light source through a projection lens toward the front of the unit, characterized in that, A light guide is disposed between the light source and the projection lens. The light guide is configured to guide the light emitted from the light source and direct the emitted light into the projection lens. The light source comprises: a first light source for forming a low-beam light distribution pattern; and a second light source for forming a high-beam light distribution pattern by simultaneously illuminating the first light source. The light guide includes: a first emission surface for emitting light for the low beam light distribution pattern; and a second emission surface for emitting light for an additional light distribution pattern added to the low beam light distribution pattern when forming the high beam light distribution pattern. The second injection surface is formed below the first injection surface at a position displaced relative to the first injection surface toward the rear of the unit. The light guide has a connecting surface that extends from the lower edge of the first emission surface toward the rear of the unit to the upper edge of the second emission surface. A mirrored surface is provided on the connecting surface. In the connecting surface, the area near the front edge of the connecting surface is configured as a light-transmitting portion. The front-to-back width of the area near the front edge is set to less than 1 / 3 of the front-to-back width of the connecting surface.
2. The lighting unit according to claim 1, characterized in that, The area of the connecting surface located near the rear focal point of the projection lens constitutes the light transmission section.
3. The lighting unit according to claim 1 or 2, characterized in that, The light guide is made of resin components.
4. The lighting unit according to claim 1 or 2, characterized in that, Equipped with multiple first light sources, The light guide has a plurality of incident portions for incidenting emitted light from each of the plurality of first light sources.