JP4676506B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a structure of a vehicle headlamp of a variable light distribution type.

In recent years, a system (AFS: Adaptive Front lighting System) that optimally controls the light distribution of a vehicle headlamp according to the traveling state of the vehicle has been proposed (for example, see Patent Documents 1 and 2). Patent Document 1 discloses a technique for swinging the light irradiation direction of a projector lamp to the left and right based on information on a steering angle, a vehicle speed, and a vehicle height. This projector lamp has a sleeve, a reflector, a lens, and a light source integrated. It is pivotally supported by being sandwiched between an upper plate and a lower plate of the bracket. It is something that swings. With such a structure, it is possible to swing the light irradiation direction from side to side.
JP 2004-224066 A JP-A-2005-347128

  However, in the conventional vehicle headlamp, since it is necessary to prepare a large actuator for swinging the entire projector lamp to the left and right, there is a problem that the size and weight of the vehicle headlamp are increased. . In addition, the conventional vehicle headlamp can move the light irradiation range left and right by swinging the irradiation direction left and right, but it does not change the shape of the light distribution pattern, so the light irradiation range is arbitrary It cannot be widened or narrowed.

  Then, in view of the said subject, this invention aims at providing the small vehicle headlamp which can change the shape of a light distribution pattern.

  A vehicle headlamp according to the present invention includes a light emitting unit, a rod integrator device that equalizes an illuminance distribution of light emitted from the light emitting unit, and a projection lens that projects light emitted from the rod integrator device. The rod integrator device is a cylindrical structure in which a plurality of light reflecting plates are combined in a cylindrical shape, and an opening at a front end portion of the cylindrical structure is disposed so as to face the projection lens. And a rod portion having a movable structure on at least one of the plurality of light reflecting plates so as to deform the shape of the opening at the front end, and a drive source for moving the light reflecting plate having the movable structure.

  According to the said structure, the opening shape of the front-end part of a cylindrical structure can be deform | transformed with the light reflection board and drive source which have a movable structure. Since the opening shape of the front end portion of the cylindrical structure is reflected in the shape of the light distribution pattern, the shape of the light distribution pattern can be changed with the deformation of the opening shape of the front end portion. In addition, according to the above configuration, the shape of the light distribution pattern can be changed simply by moving the light reflecting plate that constitutes the rod portion. Therefore, a small driving source is required compared to the conventional technology in which the entire projector lamp is swung left and right. Therefore, it is possible to reduce the size of the vehicle headlamp.

  The best mode for carrying out the present invention will be described in detail with reference to the drawings.

  1A and 1B are diagrams showing an arrangement relationship of main components included in a vehicle headlamp according to an embodiment of the present invention. FIG. 1A is a perspective view, FIG. 1B is a front view, and FIG. FIG.

  The vehicle headlamp 10 includes a housing 11, a base 12, a white LED 13, a rod integrator device 14, and a projection lens 15 as main components. Reference numerals 16, 17, 18, and 19 written in (b) represent contour lines of the housing 11, the white LED 13, the rod integrator device 14, and the projection lens 15, respectively.

  The housing 11 accommodates a projector lamp including a base 12, a white LED 13, a rod integrator device 14 and a projection lens 15. The base 12 fixes the white LED 13 and the rod integrator device 14 and also functions as a heat sink. The white LED 13 is obtained by covering a light emitting surface of a blue LED with a member containing a yellow phosphor. The rod integrator device 14 is of a so-called hollow type, and uniformizes the illuminance distribution of light by multiple reflection of light on the inner surface of the rod portion which is a cylindrical structure. The white LED 13 is disposed in the cylinder at the rear end of the cylindrical structure, and the projection lens 15 is disposed so as to face the opening at the front end of the cylindrical structure. The light emitted from the white LED 13 has a uniform illuminance distribution in the rod portion and is projected to the outside through the projection lens 15.

  FIG. 2 is a diagram showing the configuration of the rod integrator device according to the embodiment of the present invention.

  The rod part which is a cylindrical structure is comprised from the lower board 21, the upper board 22, the right side board 23, and the left side board 24 as a light reflection board. The lower plate 21 and the upper plate 22 are arranged to face each other in the up-down direction, and the right side plate 23 and the left side plate 24 are arranged to face each other in the left-right direction. The left and right side plates 23 and 24 are disposed in the gap between the lower plate 21 and the upper plate 22 so that the lower end surface and the upper end surface thereof are in contact with the upper surface of the lower plate 21 and the lower surface of the upper plate 22, respectively. Further, a light shielding plate 32 for forming a light distribution pattern of a passing beam is disposed on the front edge of the lower plate 21.

  The lower plate 21, the upper plate 22, the right side plate 23, and the left side plate 24 are all formed on the inner surface of the cylindrical structure so as to reflect light efficiently. The reflecting surface can be realized by, for example, forming a dielectric multilayer film or a metal thin film on the main surface of the base material of the light reflecting plate, or making the light reflecting plate itself made of metal such as stainless steel or aluminum. .

  The lower plate 21, the upper plate 22, the right side plate 23 and the left side plate 24 are held as a cylindrical structure by a holding member 28. The holding member 28 fixes the stators of the motors 29, 30, and 31 via the housing cases 25, 26, and 27. The rear edges of the right side plate 23, the left side plate 24 and the lower plate 21 are connected to the rotors of the motors 29, 30 and 31. With this configuration, the lower plate 21, the right side plate 23, and the left side plate 24 are pivotally supported by the holding member 28 so that the front end edge is a free end and the rear end edge is a fixed end. Since the width of the lower plate 21 and the upper plate 22 in the left-right direction is wider than the width between the rear edges of the right plate 23 and the left plate 24, even if the left and right side plates 23, 24 are swung. The lower end surface and the upper end surface of the lower plate 21 can be kept in contact with the upper surface of the lower plate 21 and the lower surface of the upper plate 22.

  The right side plate 23 is composed of a face material 23a fixed in the up-down direction and a face material 23b slidable in the up-down direction. The face material 23b is lowered by its own weight, and is raised by the pressing force of the lower plate 21. With this configuration, even if the lower plate 21 is swung, it is possible to maintain a state in which the lower end surface of the right plate 23 is in contact with the upper surface of the lower plate 21. The left side plate 24 has the same configuration.

  Specific dimensions of the internal space of the rod portion are a width of 0.5 mm to 30 mm in the left-right direction, a height of 0.5 mm to 10 mm in the vertical direction, and a depth of 1 mm to 100 mm in the front-rear direction. From the viewpoint of uniform illuminance distribution, the depth dimension is preferably about 2 to 10 times the shorter dimension of the width and height.

  With such a configuration, it is possible to realize deformation of the shape of the opening 33 at the front end portion of the rod portion which is a cylindrical structure. An example of operation when the shape of the opening 33 at the front end of the rod part is deformed and a change in the shape of the light distribution pattern when the shape of the opening 33 at the front end of the rod part is deformed are shown below.

  FIG. 3 is a diagram for explaining a standard state of the rod portion, in which (a) is a top view and (b) is a front view. In the standard state, the lower plate 21 and the upper plate 22 are parallel, and the right side plate 23 and the left side plate 24 are parallel. 4A and 4B are diagrams for explaining a displacement state in which the left and right side plates of the rod portion are moved. FIG. 4A is a top view, FIG. 4B is a front view, and FIG. 4C is a side view. The right side plate 23 swings around the support shaft 23 s by the rotational drive of the motor 29. Similarly, the left side plate 24 swings around the support shaft 24 s by the rotational drive of the motor 30. As a result, the shape of the opening 33 at the front end of the rod portion is deformed in the left-right direction. In this example, both the right side plate 23 and the left side plate 24 are swayed, but only one of them can be swayed, or the amount of displacement of the swaying can be made different between right and left. FIG. 5 is a view for explaining a displacement state in which the lower plate of the rod portion is moved, (a) is a front view, and (b) is a side view. The lower plate 21 swings around the support shaft 21 s by the rotational drive of the motor 31. Guide grooves 24c and 24e are formed in the face material 24a constituting the left side plate 24, and engaging portions 24d and 24f that engage with the guide grooves are formed in the face material 24b. The same applies to the right side plate 23. The face material 23 b of the right side plate 23 and the face material 24 b of the left side plate 24 are lowered by their own weight in conjunction with the swing of the lower plate 21. As a result, the shape of the opening 33 at the front end portion of the rod portion is deformed downward.

  FIGS. 6A and 6B are diagrams for explaining a change in the shape of the light distribution pattern due to the wobbling of the lower plate of the rod portion. FIG. 6A shows the light distribution pattern in the standard state, and FIG. 6B shows the lower plate lowered. The light distribution pattern is shown. In the optical system of the present embodiment, a center-point symmetric relationship is established between the shape of the opening 33 of the rod portion and the shape of the light distribution pattern 41. Therefore, the shape of the lower edge of the opening 33 of the rod part is reflected in the shape of the upper edge 42 of the light distribution pattern 41. As shown in the drawing, the upper edge of the light distribution pattern 41 can be raised by lowering the lower plate 21 of the rod portion.

  FIG. 7 is a diagram for explaining the change in shape of the light distribution pattern due to the wobbling of the left and right side plates of the rod portion. FIG. 7A shows the light distribution pattern when the left side plate 24 is swung to the left. ) Shows the light distribution pattern in the standard state, and (c) shows the light distribution pattern when the right side plate 23 is swung to the right. For the same reason as described above, the shapes of the right edge and the left edge of the opening 33 of the rod portion are reflected in the shapes of the left edge and the right edge of the light distribution pattern 41, respectively. As shown in the figure, the right end edge 43 of the light distribution pattern 41 can be swung to the right by swinging the left side plate 24 to the left, and the left end edge 44 of the light distribution pattern 41 can be swung to the right by swinging the right side plate 23 to the right. Can swing left.

  FIG. 8 is a graph showing the results of the effect confirmation test of the rod integrator device according to the embodiment of the present invention. The curve 51 was obtained by irradiating light using a rod portion corresponding to the standard state and measuring the illuminance at each point in the horizontal direction. Curve 52 is obtained by irradiating light using a rod portion corresponding to a displacement state in which only the left side plate is swung to the left without moving the right side plate 23 from the standard position, and measuring the illuminance at each point in the horizontal direction. Obtained. According to this, it is understood that the position of the right edge can be moved to the right while maintaining the position of the left edge of the light distribution pattern by shaking only the left side plate to the left (reference numeral 53). If the left side plate is moved to the left, the peak of illuminance decreases (reference numeral 54), but the decrease in the peak of illuminance can be suppressed by increasing the current flowing through the white LED.

  FIG. 9 is a diagram illustrating a configuration for realizing AFS.

  The control unit 66 acquires the steering information and the speed information via the external interface 65, and determines the current flowing through the white LED 13 and the rotation angles of the motors 29, 30, and 31 based on these information. The lighting circuit 61 causes a current corresponding to the data input from the control unit 66 to flow through the white LED 13. The drivers 62, 63, and 64 rotate the motors 29, 30, and 31 by an angle corresponding to the data input from the control unit 66. With this configuration, AFS can be realized.

As mentioned above, although the vehicle headlamp which concerns on this invention was demonstrated based on embodiment, this invention is not limited to these embodiment. For example, the following modifications can be considered.
(1) In the embodiment, a motor is employed as a drive source of the light reflecting plate having a movable structure, but the present invention is not limited to this. For example, a piezoelectric actuator may be employed as the drive source. FIG. 10, FIG. 11 and FIG. 12 show an operation example when a piezoelectric actuator is employed as a drive source. 10, FIG. 11 and FIG. 12 correspond to FIG. 3, FIG. 4, and FIG. Is different. Since the movable range of the piezoelectric actuator currently on the market is about 0.5 mm at the maximum, it can be used sufficiently.

Further, the same driving method as that of the MEMS mirror can be adopted. In this case, a movable electrode is provided in the vicinity of the free end of the light reflecting plate having a movable structure, and a fixed electrode is provided on the holding member that holds the light reflecting plate so as to face the movable electrode. This can be realized by providing a unit for applying an arbitrary voltage between them.
(2) In the embodiment, the light shielding plate 32 is disposed at the front edge of the lower plate 21 in order to obtain the light distribution pattern of the passing beam. However, the present invention is not limited to this. For example, when a separate light shielding plate is provided between the rod integrator device and the projection lens, the rod integrator device does not require a light shielding plate (see FIG. 13). Moreover, it is good also as obtaining the light distribution pattern of a passing beam by giving a level | step difference to the lower board 21 (refer FIG. 14).
(3) In the embodiment, the light shielding plate 32 is fixed to the front edge of the lower plate 21, but the present invention is not limited to this. For example, the light shielding plate 32 may be provided with a movable structure to switch between the passing beam and the traveling beam. 15A and 15B are diagrams showing an operation example of the rod integrator device when the light shielding plate has a movable structure, in which FIG. 15A is a front view of a passing beam state, FIG. 15B is a side view of a passing beam state, and FIG. ) Is a light distribution pattern in a passing beam state, (d) is a front view in the traveling beam state, (e) is a side view in the traveling beam state, and (f) is a light distribution pattern in the traveling beam state. The support shaft 32 s of the light shielding plate 32 is connected to the rotor of the motor 34, and the stator of the motor 34 is fixed to the front end edge of the lower plate 21. The motor 34 moves the shading plate 32 up and down in a standing posture and a recumbent posture around the support shaft 32s. With such a configuration, it is possible to provide a step on the upper edge 42 of the light distribution pattern 41 with a single vehicle headlamp, or to flatten the upper edge 45 of the light distribution pattern 41.
(4) In the embodiment, the three light reflecting plates of the lower plate 21, the right side plate 23, and the left side plate 24 are provided with a movable structure. However, the present invention is not limited to this, and the movable structure is provided only on the lower plate 21. Alternatively, only two of the right side plate 23 and the left side plate 24 may have a movable structure, or all of the lower plate 21, the upper plate 22, the right side plate 23, and the left side plate 24 may have a movable structure.
(5) In the embodiment, white light is obtained by a combination of a blue LED and a yellow phosphor. However, the present invention is not limited to this, and the purpose is to improve the color temperature freedom, improve the color rendering, or increase the light emission efficiency. It is also possible to use a combination of a blue LED and a phosphor emitting yellow and red light, or a combination of an ultraviolet LED and each phosphor emitting three primary colors (red, green, blue), and a fluorescent light emitting orange. The body may be included in the combination to obtain white light. Further, as the light emitting part, a visible light LED having a single spectrum shape such as red, orange, yellow, green, and blue may be combined to obtain an arbitrary emission color, and a phosphor having an arbitrary emission spectrum and its phosphor An arbitrary emission color may be obtained by combining the excitation LED and the visible light LED.
(6) In the embodiment, a white LED, which is one of semiconductor light emitting elements, is employed as the light emitting unit. An HID lamp or the like may be employed. However, when a semiconductor light emitting element is adopted, it can greatly contribute to miniaturization of a vehicle headlamp.
(7) In the embodiment, the support shaft of the light reflection plate is connected to the rotor of the motor, but this may be directly connected or indirectly via a power transmission mechanism such as a gear or a belt. It is good also as being connected to.
(8) In the embodiment, the cylindrical structure is a square cylindrical shape, but may be a polygonal cylindrical shape or a semicylindrical shape.

  The present invention can be used for, for example, a headlight for an automobile.

It is a figure which shows the arrangement | positioning relationship of the main structures contained in the vehicle headlamp which concerns on embodiment of this invention, (a) is a perspective view, (b) is a front view, (c) is a side view. The figure which shows the structure of the rod integrator apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the standard state of a rod part, (a) is a top view, (b) is a front view It is a figure for demonstrating the displacement state which moved the right-and-left side board of the rod part, (a) is a top view, (b) is a front view, (c) is a side view. It is a figure for demonstrating the displacement state which moved the lower board of the rod part, (a) is a front view, (b) is a side view. It is a figure for demonstrating the shape change of the light distribution pattern by the rocking | fluctuation of the lower board of a rod part, (a) is a light distribution pattern in a standard state, (b) is a light distribution pattern when a lower board is lowered | hung It is a figure for demonstrating the shape change of the light distribution pattern by the swaying of the right-and-left side board of a rod part, (a) is a light distribution pattern when the left board 24 is shaken to the left, (b) is the distribution in a standard state. (C) Light distribution pattern when the right side plate 23 is shaken to the right The graph which shows the result of the effect confirmation test of the rod integrator apparatus which concerns on embodiment of this invention The figure which shows the structure for implement | achieving AFS It is a figure for demonstrating the standard state of a rod part, (a) is a top view, (b) is a front view It is a figure for demonstrating the displacement state which moved the right-and-left side board of the rod part, (a) is a top view, (b) is a front view, (c) is a side view. It is a figure for demonstrating the displacement state which moved the lower board of the rod part, (a) is a front view, (b) is a side view. The figure which shows the structure of the rod integrator apparatus which concerns on embodiment of this invention. The figure which shows the structure of the rod integrator apparatus which concerns on embodiment of this invention. It is a figure which shows the operation example of a rod integrator apparatus when a light-shielding plate has a movable structure, (a) is a front view of a passing beam state, (b) is a side view of a passing beam state, and (c) is a passing beam. (D) is a front view of the traveling beam state, (e) is a side view of the traveling beam state, and (f) is a light distribution pattern of the traveling beam state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Headlamp for vehicles 11 Housing 12 Base 13 White LED
DESCRIPTION OF SYMBOLS 14 Rod integrator apparatus 15 Projection lens 21 Lower plate 22 Upper plate 23 Right side plate 24 Left side plate 25, 26, 27 Storage case 28 Holding member 29, 30, 31, 34 Motor 32 Light-shielding plate 33 The rod part which is a cylindrical structure Front end opening 61 Lighting circuit 62, 63, 64 Driver 65 External interface 66 Control unit 71, 72, 73 Piezoelectric actuator

Claims (11)

A light emitting unit, a rod integrator device that equalizes the illuminance distribution of the light emitted from the light emitting unit, and a projection lens that projects the light emitted from the rod integrator device,
The rod integrator device is
A cylindrical structure in which a plurality of light reflecting plates are combined in a cylindrical shape, and the opening at the front end of the cylindrical structure is disposed so as to face the projection lens, and the opening at the front end is A rod portion having a movable structure in at least one of the plurality of light reflecting plates so as to deform the shape;
A vehicle headlamp, comprising: a drive source that moves the light reflector having the movable structure. The rod portion includes a holding member that holds the plurality of light reflecting plates, and the light reflecting plate having the movable structure has an edge corresponding to a front end portion of the cylindrical structure as a free end, and the cylindrical shape. The vehicle headlamp according to claim 1, wherein an end edge corresponding to a rear end portion of the structure is pivotally supported by the holding member so as to be swingable. The cylindrical structure is composed of upper and lower light reflecting plates facing in the vertical direction, and left and right light reflecting plates facing in the left and right direction provided in a gap between the upper and lower light reflecting plates. 3. The vehicle according to claim 2, wherein the reflector has the movable structure, and a width in the left-right direction of the upper and lower light reflectors is wider than a width between fixed ends of the left and right light reflectors. Headlight. The lower light reflecting plate has the movable structure, and the left and right light reflecting plates have a structure that can extend and contract in the vertical direction in conjunction with the lower light reflecting plate. 4. A vehicle headlamp according to 3. 5. The vehicle according to claim 4, wherein each of the left and right light reflecting plates is configured by superimposing a plurality of face materials, and extends and contracts in a vertical direction when the plurality of face materials slide relative to each other. Headlight. The cylindrical structure is composed of upper and lower light reflecting plates facing in the vertical direction, and left and right light reflecting plates facing in the left and right direction provided in a gap between the upper and lower light reflecting plates. A light-shielding plate for providing a step at a lower end edge of the opening of the front end portion of the cylindrical structure is provided at an edge corresponding to the front end portion of the cylindrical structure in the light reflecting plate. The vehicle headlamp according to claim 1. The vehicle headlamp according to claim 6, wherein the light shielding plate has a movable structure, and the rod integrator device further includes a drive source that moves the light shielding plate having the movable structure. The cylindrical structure is composed of upper and lower light reflecting plates facing in the vertical direction, and left and right light reflecting plates facing in the left and right direction provided in a gap between the upper and lower light reflecting plates. The vehicular headlamp according to claim 1, wherein the light reflecting plate is bent at a substantially center when viewed from an opening at a front end portion of the cylindrical structure, and has a step on the left and right of the center. . The vehicle headlamp according to claim 1, wherein the drive source is a motor or a piezoelectric actuator. A movable electrode is provided on the light reflecting plate having the movable structure, and a fixed electrode is provided on the holding member that holds the light reflecting plate so as to face the movable electrode. An arbitrary voltage is provided between the movable electrode and the fixed electrode. The vehicle headlamp according to claim 1, further comprising a unit that applies The vehicle headlamp according to claim 1, wherein the light emitting unit is a semiconductor light emitting element.

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