The present application claims priority from Japanese Patent Application No. 2014-018767 filed on Feb. 3, 2014, the entire content of which is incorporated herein by reference.
1. Field of Invention
The present disclosure relates to a vehicle lamp.
2. Related Art
Proposals exist for a vehicle lighting device that forms a desired light distribution pattern by reflecting light emitted from a light source, using a reflection direction converter disposed with plural reflection elements in a matrix formation, and passing the reflected light through a lens (see Patent Document 1). Such a vehicle lighting device can form plural shapes of light distribution pattern by controlling some of multi-arrayed reflection elements so that some of the light emitted from the light source is reflected in a direction other than toward the lens.
Patent Document 1: JP-A-9-104288
However, in the vehicle lighting device mentioned above, stray light may occur due to reflection from various components provided in the vehicle lighting device and stray light may occur due to malfunction of the reflection elements, even when the reflective state of some of the reflection elements is controlled such that some of the light emitted from the light source is reflected in a direction other than toward the lens.
Exemplary embodiments of the invention provide a vehicle lamp with little glare.
A vehicle lamp according to an exemplary embodiment of the invention comprises:
a 2D image forming device configured to form a brightness image using light emitted from a light source;
an optical projection system configured to project the brightness image forward; and
a light blocking member disposed on a path of light emitted from the light source through the 2D image forming device and onward toward the optical projection system, and configured to block at least a portion of the light.
For example, when the 2D image forming device is a transmission type device, even if ideally at least some of the configuration elements are in a state not permitting light transmission forward, sometimes light is transmitted due to insufficient opaqueness of the configuration elements or malfunction of the configuration elements. Moreover, when the 2D image forming device is a reflection type device, even if ideally at least some of the configuration elements are in a state not reflecting light forward, sometimes stray light is generated due to reflection of a cover glass covering the device, or malfunction of the reflection configuration elements. Accordingly light that should not really be transmitted, or reflected stray light, may actually be projected by the optical projection system, resulting in glare to pedestrians and other transport users, such as the vehicle in front.
The above aspect is capable of suppressing glare from occurring due to being able to block light with the light blocking member, even if light is transmitted that should not really be transmitted, or stray light occurs due to reflection.
The light blocking member may include a light blocking region configured to block light emitted from the light source. The light blocking region may be made of a material having a reflectivity of 15% or less. Thereby, glare due to reflected light occurring when light emitted from a light source is blocked in a light blocking region can be suppressed.
The vehicle lamp may further comprise a movement mechanism configured to move the light blocking member. The movement mechanism may be configured to move the light blocking member between a first position when forming a first light distribution pattern, and a second position when forming a second light distribution pattern different from the first light distribution pattern. Thereby, plural light distribution patterns can be realized.
The light blocking member may include a cutline forming portion configured to form a cutline of a low beam light distribution pattern. Thereby, a cutline of a shape not obtainable using the 2D image forming device alone can be formed.
The light blocking member may be disposed on a path of light emitted from the light source toward the 2D image forming device. Light that should not really be transmitted in the 2D image forming device and stray light due to reflection does not accordingly occur due to light blocked by the light blocking member not reaching the 2D image forming device.
The light blocking member may be disposed between the 2D image forming device and the optical projection system. Thus even suppose light that should not really be transmitted in the 2D image forming device or stray light due to reflection occurs, then such light can be prevented from reaching the optical projection system.
Various combinations of relevant configuration elements described above, and changes between expressions of the invention, such as a method, a device, a system, or the like, are also valid embodiments of the invention.
According to the exemplary embodiments of the invention, it is possible to achieve a vehicle lamp with little glare.
Detailed explanation follows regarding embodiments to implement the invention, with reference to the drawings. Similar elements in the drawing explanations are appended with the same reference numerals, and duplicate explanation thereof will be omitted as appropriate.
A vehicle lamp 10 includes a light source 12, a 2D image forming device 14 that forms a brightness image using light emitted from the light source 12, a projection lens 16 serving as an example of an optical projection system that projects the brightness image forward, and a light blocking member 18 that is disposed on the path of light emitted from the light source 12, through the 2D image forming device 14, and onward toward the projection lens 16, and blocks at least some of the light.
Various devices applied to vehicle lamps may be employed for the light source 12. Examples thereof include a light bulb, a discharge lamp, an LED, an LD, and a neon tube. A combination of plural devices may also be employed, according to application and performance demands. Depending on the device, the brightness may also be controlled by lighting on or off some elements, or performing PWM control.
The 2D image forming device 14 is a transmission type device capable of controlling the proportion of light to be transmitted. A liquid crystal panel or the like with elements disposed in a matrix formation is, for example, suitably employed therefor. The projection lens 16 projects light that has passed through the 2D image forming device 14 as a specific light distribution pattern in front of a vehicle. For example, the vehicle lamp 10 illustrated in
When the 2D image forming device 14 is a transmission type device, as described above, even if ideally at least some of the liquid crystal elements are in a state not transmitting light forward, sometimes some light is transmitted due to a small amount of light leakage in the liquid crystal elements or malfunction of the liquid crystal elements. The light blocking member 18 is accordingly moved, as illustrated in
Note that, as in the vehicle lamp 20 illustrated in
As illustrated in
The light blocking member 18 includes a light blocking region 18b blocking light emitted from the light source 12 that has been transmitted through the 2D image forming device 14. The surface of the light blocking region 18b may be made of a material having a reflectivity of 15% or less to light from the light source. Generation of glare from reflected light can thereby be suppressed when using the light blocking region to block light emitted from the light source 12 that has passed through the 2D image forming device 14.
A light blocking member 22 illustrated in
A light blocking member 24 illustrated in
The shape at the ends of each of the light blocking members described above may also be a curved shape in consideration of the field curvature of an optical projection system.
A vehicle lamp 30 includes a light source 12, a reflector 32 that reflects light so as to concentrate light emitted from the light source 12, a 2D image forming device 34 that forms a brightness image with the light reflected by the reflector 32, a projection lens 16 that projects the brightness image forward, and a light blocking member 18 disposed on the path of light emitted from the light source 12, through the 2D image forming device 34, and onward toward the projection lens 16, and blocks at least some of the light.
The 2D image forming device 34 is a reflection type device that is capable of controlling a direction in which light is reflected. Examples of devices suitably employed therefor include a reflection type liquid crystal panel disposed with liquid crystal elements in a matrix formation, and a micro electro mechanical system (MEMS) with micro minors disposed in a matrix formation. A reflection face of the 2D image forming device 34 is sometimes provided with a transparent cover to protect the liquid crystals or micro mirrors from the external environment. The projection lens 16 projects a specific light distribution pattern of light that has been reflected by the 2D image forming device 34 in front of a vehicle. For example, the vehicle lamp 30 illustrated in
When the 2D image forming device 34 is a reflection type device, as described above, even if ideally at least some of the liquid crystal elements or micro mirrors are in a state not reflecting light forward toward the projection lens, sometimes some stray light is generated due to reflection of a transparent cover covering the device or malfunction of the liquid crystal- or micro mirror-configuration elements. The light blocking member 18 is accordingly moved, as illustrated in
A reflection face 18c (see
Each of the above vehicle lamps equipped with the respective light blocking sections and 2D image forming devices is particularly favorably applied to a fog lamp or a low beam headlamp. This is because it is difficult to completely avoid unnecessary reflected light and leaking light in lamps that do not have a light blocking section, and only include a 2D image forming device, and it is accordingly difficult to satisfy the required value for contrast between illumination portions and non-illumination portions of light distribution patterns for use in fog and low beam lamps.
Each of the above vehicle lamps is, for example, a configuration suitable for use as a low beam lamp or a fog lamp with an adaptive driving beam (ADB) using a MEMS mirror array.
The invention has been described in detail and by reference to the respective embodiments and its modified examples; however, the invention is not limited to them and includes various combination or substitution of structures of the respective embodiments. Further, based on the knowledge of the person skilled in the art, it is possible to change the orders of combination or processes in each of the embodiments, or to add the modification such as design change and the like to each of the embodiments. The embodiments to which such modifications are added can be included in the scope of the invention.
Number | Date | Country | Kind |
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2014-018767 | Feb 2014 | JP | national |