WO2016170837A1 - Vehicular headlight - Google Patents

Abstract

The objective of the present invention is to provide a vehicular headlight allowing light distribution to be designed with a high degree of freedom and maintained safely even when a semiconductor laser is used as a light emitting element. This vehicular headlight is equipped with: a light emitting element emitting coherent light; a light projection optical system whereby light from a light radiation region, formed by the light from the light emitting element, is projected to form a lighting region having a defined shape; and a deflection pattern generation means for conversion into an outgoing luminous flux having a defined light distribution for long-range lighting. The deflection pattern generation means is configured in such a manner that: the light entry portion thereof is constituted by being divided into multiple deflection function regions; when each of the incoming beams entering the light entry portion is deflected and sent out, the direction of the deflection is dependent on the entry position of the light beam in the light entry portion; and each of the deflection function regions illuminates a wide region within the entire light distribution region in which the light is distributed.

Description

Automotive headlamp

The present invention relates to an in-vehicle headlamp using a light emitting element such as a semiconductor laser.

Traditional light source lamps such as halogen lamps have long been used as the light source for in-vehicle headlamps, but HID lamps such as long-lived metal halide lamps, and in recent years, even longer and more efficient LEDs Also came to be used.
In this way, the light source element itself has evolved with the aim of extending the life and efficiency, but the control of the headlamp luminous flux is mainly to switch between so-called high beam and low beam (passing headlight). It was.

Recently, however, research aimed at realizing a headlamp with improved light utilization efficiency by using a light emitting element of a solid-state laser such as a semiconductor laser has been conducted, and many proposals have been made.
For example, Japanese Patent Laid-Open No. 2013-084530 proposes a method of generating a headlamp light beam by deflecting and scanning a laser beam using a piezoelectric actuator, and a cut line that is an upper limit in the case of a low beam. In order to realize the above, control that is arbitrarily generated from on / off control of the laser light source is described.
However, in the case of this technique, since a desired light distribution is obtained by two-dimensional deflection scanning, the degree of freedom in changing the dynamic light distribution condition may be high, but it is emitted as a headlamp light beam. Because the instantaneous and instantaneous illumination laser beam is in the form of a thin beam, special measures are required to ensure the safety of human eyes such as pedestrians, but this is an unsolved problem There is.

Japanese Patent Application Laid-Open No. 2013-125893 discloses a two-dimensional galvanometer (or polygon mirror) that generates white laser light generated by mixing three primary colors of R, G, and B to improve visibility. Is used to generate a headlamp light beam having a desired light distribution by performing deflection scanning using the.
For example, there are proposals to increase the bluishness of the illumination light on the shoulder of the road, reduce the color temperature when driving for a long time, when the driver is elderly, or illuminate pedestrians with a prominent color. included. However, similarly in this technique, since the laser light emitted as the headlamp light beam has a thin beam shape, there is a problem that the above-described measures for ensuring safety are unsolved.

On the other hand, Japanese Patent Application Laid-Open No. 2012-146621 describes a method in which a hologram is illuminated with a semiconductor laser and a diffracted light generates a headlamp light beam having a desired light distribution.
For this purpose, a hologram that can be selected from a plurality of different holograms according to the rotation stop position, or a liquid crystal prism that changes the direction of the illumination light according to the applied voltage, and switches the light distribution between the high beam and the low beam depending on the voltage. Proposals for things are included.
In the case of this technology, the laser light emitted as the headlamp luminous flux is not in the form of a thin beam unlike the above-mentioned ones, so the danger to human eyes is low, but the headlamp luminous flux is human The possibility of causing danger in direct shooting at a close distance is not excluded depending on the distance when the eyes are directly irradiated.

Therefore, Japanese Patent Laid-Open No. 2012-006493 provides a detection unit that can detect the presence of a person using an infrared sensor, an ultrasonic sensor, a millimeter wave radar, a visible light camera, etc., and detects a person. In such a case, there has been proposed a technique for avoiding danger to human eyes by controlling to reduce or stop the laser output of the headlamp.
However, providing such a detection unit increases the cost of the system, and if there is a detection delay or failure, a dangerous state is maintained, so safety is sufficient. I can't say there is.

JP2013-084530A JP 2013-125893 A JP 2012-146621 A JP 2012-006493 A

A problem to be solved by the present invention is to provide an in-vehicle headlamp that can maintain safety even when a semiconductor laser is used as a light emitting element and can design a light distribution with a high degree of freedom. There is.

The in-vehicle headlamp according to the first aspect of the present invention includes a light emitting element (Sc) that emits coherent light,
A power feeding circuit (Ps) for driving the light emitting element (Sc);
Light projection having a light emission region (Gs) formed by light from the light emitting element (Sc) and projecting the light from the light emission region (Gs) to form a prescribed shape illumination region (Gu) An optical system (Eu);
Installed in the vicinity of the illumination area (Gu), each incident light beam incident on it is deflected and emitted, and converted into an emitted light beam (Bmo) having a prescribed light distribution that illuminates a distant area. A vehicle-mounted headlamp comprising a deflection pattern generating means (Fm) for
The deflection pattern generating means (Fm) is configured such that the light incident portion (Pmi) is divided into a large number of deflection function regions (R1, R2,...) And is incident on the light incident portion (Pmi). When each of the incident light beams is deflected and emitted, the direction of deflection to be applied is configured to depend on the incident position of the light beam in the light incident portion (Pmi), and the deflection function area (R1, R1). Each of R2,... Illuminates a wide area of the entire area where the light distribution of the light distribution described above is performed.

The in-vehicle headlamp according to the second aspect of the present invention forms a light beam deflected by one of the deflection function regions (R1, R2,...) At the closest position where the presence of human eyes is assumed. The light power incident on each of the deflection function regions (R1, R2,...) So that the illuminance to be reduced is below a level that can be protected from eye damage by the avoidance action that a person naturally performs against exposure to dazzling light. Is specified.

In the vehicle headlamp according to the third aspect of the present invention, the size of the deflection function area (R1, R2,...) In the direction corresponding to the longitudinal direction of the emitted light is equal to the light distribution described above. The following value Aymin = 4λ / Θy calculated by the angular width Θy in the longitudinal radians and the wavelength λ of the emitted light of the light emitting element (Sc)
It is the above, It is characterized by the above.

According to a fourth aspect of the present invention, the in-vehicle headlamp has an arrangement resolution distance of the deflection function areas (R1, R2,...), An angular resolution Ψ in radians of a typical human eye, and the light emitting element. The next value calculated by the wavelength λ of the emitted light of (Sc) Cmin = λ / Ψ
It is the above, It is characterized by the above.

The on-vehicle headlamp according to a fifth aspect of the present invention is characterized in that the arrangement is modulated so as to give a disturbance to the periodicity of the arrangement of the deflection function areas (R1, R2,...). It is.

According to a sixth aspect of the present invention, there is provided the in-vehicle headlamp according to the present invention, in order to realize that the deflection direction given depends on the incident position of the light beam in the light incident part (Pmi). The means (Fm) is constituted by a light reflecting surface whose normal direction changes depending on the position.

According to a seventh aspect of the present invention, there is provided the in-vehicle headlamp according to the present invention, in order to realize that the direction of the deflection given depends on the incident position of the light beam in the light incident portion (Pmi). The means (Fm) is constituted by a photorefractive medium whose thickness or refractive index changes depending on the position.

According to an eighth aspect of the present invention, there is provided an in-vehicle headlamp that generates the deflection pattern in order to realize that the direction of deflection given depends on the incident position of the light beam at the light incident portion (Pmi). The means (Fm) is constituted by a diffraction grating having an interference fringe whose phase changes depending on the position.

The on-vehicle headlamp according to the ninth aspect of the present invention comprises a plurality of deflection pattern generation means (Fm, Fm ′,...) Having different light distributions. The relative positional relationship between the deflection pattern generation means (Fm, Fm ′,...) And the illumination area (Gu) can be changed so that the illumination area (Gu) is positioned. .

A vehicle headlamp according to a tenth aspect of the present invention includes a plurality of deflection pattern generating means (Fm, Fm ′,...) Having different light distributions arranged close to each other, and the deflection pattern generating means ( Fm, Fm ′,...) And the illumination area (Gu) are two intermediate positions adjacent to each other in the deflection pattern generation means. It is characterized in that a light distribution is formed by adding the light distribution formed by each of the deflection pattern generating means alone.

The on-vehicle headlamp according to the eleventh aspect of the present invention further includes an integrated control circuit (Ux) that controls the power feeding circuit (Ps) to determine the input power to the light emitting element (Sc), The integrated control circuit (Ux) recognizes the relative positional relationship between the deflection pattern generation means (Fm, Fm ′,...) And the illumination area (Gu), and the deflection pattern generation means (Fm, Fm ′,. ..) And the illumination region (Gu), the feeding circuit (Ps) is controlled so as to change the input power to the light emitting element (Sc) according to the relative positional relationship. .

Even when a semiconductor laser is used as a light emitting element, safety can be maintained, and an in-vehicle headlamp that can design a light distribution with a high degree of freedom can be provided.

The block diagram which simplifies and shows the vehicle-mounted headlamp of this invention is represented. The conceptual diagram which simplifies and shows a part of vehicle-mounted headlamp of this invention is represented. The conceptual diagram which simplifies and shows a part of vehicle-mounted headlamp of this invention is represented. The schematic diagram which simplifies and shows a part of vehicle-mounted headlamp of this invention is represented. The schematic diagram which simplifies and shows a part of vehicle-mounted headlamp of this invention is represented. The schematic diagram which simplifies and shows a part of vehicle-mounted headlamp of this invention is represented. The schematic diagram which simplifies and shows a part of vehicle-mounted headlamp of this invention is represented. The schematic of the concept relevant to the technique of the vehicle-mounted headlamp of this invention is represented.

In the description of the present invention, regarding the term conjugate, as a general term in the field of geometric optics, for example, when A and B are conjugate, it has an imaging function such as a lens based on at least paraxial theory. It means that A is imaged on B or B is imaged on A by the action of the optical element.
At this time, A and B are images, and it is a matter of course that isolated point images are included as targets, and a set of a plurality of point images and a spread image in which point images are continuously distributed are also targets. include.

Here, a point image or an image point (that is, an image) is a general term in the field of geometric optics, in which light is actually radiated from that point, the light converges toward that point, and the screen is A bright spot appears when placed, the light seems to converge toward that point (but the point is inside the optical system and the screen cannot be placed), the light is emitted from that point (However, the point is inside the optical system and the screen cannot be placed), and no distinction is made. At this time, blurring occurs due to aberrations or defocusing in imaging, Ignore the phenomenon of disappearing from an ideal point or diffraction limited image.

In addition, a light emitting area is a space or surface that emits light or is irradiated with light, and may include the above-mentioned image. Similarly, light is actually emitted from that area. , The light converges toward the area and the screen is placed to show a bright area, and the light appears to converge toward the area (but the area is inside the optical system This includes and does not distinguish between things that cannot be screened) and light that appears to be emitted from that area (but that area is inside the optical system and cannot be screened).
Furthermore, a radiation surface element refers to an image point constituting a light radiation area or a small light radiation area.

In the case where the light emitting element (Sc) is a semiconductor laser, if there is one semiconductor laser, the light emitting region (Gs) may be considered as just one point light source, and usually it is the optical system. It may be placed on the optical axis and arranged in a direction in which the central ray of the diverging direction distribution of the diverging light from the semiconductor laser coincides with the optical axis.
However, in the case of a light source that a plurality of semiconductor lasers have, or a light source in which radiating surface elements are continuously distributed within a finite area, a design that takes into account the entrance pupil, exit pupil, and chief ray of the optical system is necessary. The following describes such a situation.

Taking an ordinary camera lens as an example, an aperture stop usually exists inside the lens, but when looking at the lens from the side where the light enters, the image of the aperture stop that can be seen through the lens is seen from the entrance pupil and the side where the light exits. When viewing the lens, the image of the aperture stop that can be seen through the lens is called the chief ray when it comes to the center of the exit pupil, entrance pupil, or emerges from the center of the exit pupil (usually the meridian ray).
In a broad sense, rays other than the principal ray are called peripheral rays.
However, in an optical system that handles light having directivity such as a laser, there is often no aperture stop because there is no need to cut out a light beam by the aperture stop, and in that case, depending on the presence form of light in the optical system, They are defined.

Normally, the central ray of the light direction distribution in the luminous flux from the radiation surface element is the principal ray, and there is an entrance pupil at the position where the principal ray incident on the optical system or its extension intersects the optical axis. The exit pupil is considered to be at a position where the exiting principal ray or its extension intersects the optical axis.
However, to be exact, there may be a case where the chief ray and the optical axis defined in this way do not intersect due to, for example, an adjustment error and are only in a twisted position.
However, since this phenomenon is irrelevant in nature and is barren to the discussion, in the following, it is assumed that such a phenomenon does not occur or the principal ray and the optical axis are closest to each other Let's consider it to be crossing in position.
Further, when attention is paid to two adjacent partial optical systems A and B in the optical system, and B is adjacent immediately after A, (the output image of A becomes the input image of B) Similarly, the exit pupil of A becomes the entrance pupil of B, and the entrance and exit pupils of the partial optical system arbitrarily defined in the optical system are all images (if there is an aperture stop). However, if they do not need to be distinguished, the entrance pupil and the exit pupil are simply referred to as pupils.

In the description and drawings of the present invention, the optical axis of the optical system is referred to as the z-axis. However, if the optical axis is bent by the reflecting mirror, the direction in which the light beam along the original z-axis is reflected and travels is also determined. It is called the z axis and does not take a new coordinate axis.
In the drawings such as FIG. 2, the x axis and the y axis are indicated as axes perpendicular to the z axis for convenience.

First, referring to FIG. 1 which is a block diagram showing a simplified vehicle headlamp according to the present invention, and FIGS. 2 and 3 which are conceptual diagrams showing a part of the vehicle headlamp according to the present invention in a simplified manner. An embodiment for carrying out the present invention will be described.
In FIG. 1, for example, when the light emitting element (Sc) is an edge emitting semiconductor laser, the diverging light emitting portion existing on the surface of the semiconductor chip housed in the semiconductor laser package is substantially a dot. It can be treated as a light source and can be used as a light emission region (Gs).
Also, when the light emitting element (Sc) is a surface emitting semiconductor laser, the light emitting surface can be the light emitting region (Gs).

FIG. 2 shows a state where the light emission region (Gs) is composed of a plurality of or distributed radiation surface elements (Ks, Ks ′,...).
Focusing on the radiation surface element (Ks), as indicated by the outermost peripheral rays (Lms1, Lms2), the radiation surface element (Ks) is within a conical angle region defined by the bottom surface (Ci). The principal ray (Lps) for the luminous flux from this radiation surface element is defined as the central ray of this luminous flux distribution.
In general terms, the principal rays (Lps, Lps ′,...) Have an angle with respect to the z-axis, which is the optical axis of the optical system, and accordingly, it is considered that a pupil exists at a point (Qs) that intersects the optical axis. .

FIG. 3 shows a state in which the light emission region (Gs) is constituted by the light exit ends of the two optical fibers (Ef1, Ef2), that is, the core on the light exit end side.
Naturally, the light emitting element exists at the light incident end opposite to the light emitting end in each of the optical fibers (Ef1, Ef2), and the light from the light emitting element is injected into each light incident end using a lens or the like. The
In this case, the radiation surface elements (Ks, Ks ′,...) May be considered to be distributed substantially uniformly at the light exit ends of the optical fibers (Ef1, Ef2). , Ks ′,...) Emit light with an apex angle in a conical angular region in which peripheral rays are distributed, which is determined by the structure of the fiber.
Further, principal rays (Lps, Lps ′,...) Of light beams emitted from the radiation surface elements (Ks, Ks ′,...) Are parallel to the fiber axis, and the optical fibers (Ef1, Ef2) are bundled. The optical axis of the optical system is arranged in parallel to the z axis.
Thus, when the chief rays (Lps, Lps ′,...) Are parallel to the optical axis of the optical system, the pupil is considered to be at infinity.
In this case, the light emitting end itself of the optical fibers (Ef1, Ef2) may be regarded as the radiation surface elements (Ks, Ks ′,...).
As described above, in the present invention, the light emission region (Gs) may be a point light source or a light emitting element itself that is a distributed light source, or may be a light guided from the light emitting element. The light may be emitted by being illuminated with light from the light emitting element.

A light projection optical system (Eu) including a lens or the like receives an input of the light beam (Bs) from the light emission region (Gs), and in the vicinity of the deflection pattern generation means (Fm) at the subsequent stage, Are arranged to form.
However, the light emission region (Gs) and the illumination region (Gu) do not have to be conjugate. The deflection pattern generation means (Fm) deflects and emits each incident light beam of the light beam (Bs) input from the light projection optical system (Eu) to the light incident portion (Pmi), The emitted light beam (Bmo) is output from the light emitting part (Pmo).

Here, the deflection pattern generation means (Fm) is configured such that the direction of deflection given depends on the incident position of the light beam in the light incident portion (Pmi).
Accordingly, by defining the dependency when the direction of the deflection given is dependent on the incident position of the light beam at the light incident part (Pmi), the state of change in the exit direction of the exit beam (Bmo), That is, it is possible to create a light distribution with respect to a distant place with a high degree of freedom.
Incidentally, the light emitting part (Pmo) does not necessarily exist as a part different from the light incident part (Pmi), and the light incident part (Pmi) is not necessarily present as the light emitting part (Pmo), as will be described later. It may also serve as

As a characteristic structure of the in-vehicle headlamp according to the present invention, as shown in FIG. 4, the deflection pattern generation means (Fm) has a light incident portion (Pmi) having a large number of deflection function regions (R1, R2, (...) is divided.
This will be described with reference to FIG. 4 which is a schematic diagram showing a part of the vehicle headlamp of the present invention in a simplified manner.
If the light emitting element (Sc) in the drawing is a semiconductor laser that emits light in an active region that can be regarded as a point light source, this active region becomes a light emitting region (Gs).
On the other hand, the light projection optical system (Eu) is constituted by a cylindrical lens in the figure, and thereby, the light beam (Bs) from the light emission region (Gs) is spread at different angles, that is, in the x-axis direction. Without changing the divergence angle, it is converted into a light beam (Bu) with a reduced divergence angle in the y-axis direction, and the non-conjugated illumination area (Gu) is converted into the light emission area (Gs) by the deflection pattern generation means (Fm). It is drawn so as to be formed in the vicinity of the light incident part (Pmi), here on the light incident part (Pmi).

As described above, the direction of deflection given to the incident light beam by the deflection pattern generating means (Fm) depends on the incident position of the light beam in the light incident part (Pmi).
In this case, the dependence characteristic on the incident position is designed so that a predetermined light distribution for illuminating a distant place is realized by the entire light beam (Bu) forming the illumination region (Gu). As described above, the deflection pattern generation means (Fm) is configured such that the light incident portion (Pmi) is divided into a large number of deflection function regions (R1, R2,...), And the deflection function. Each of the regions (R1, R2,...) Is designed to illuminate a wide region of the entire region where the light distribution of the light distribution described above is performed.

In FIG. 4, the light projection optical system (Eu) is exemplified by a single cylindrical lens, but the light projection optical system (Eu) is configured by a combination lens with a spherical lens. Alternatively, it may be constituted by a molded aspheric lens or a curved mirror.

Even in conventional in-vehicle headlamps using halogen lamps, HID lamps, and LEDs as light sources, the concave reflecting mirror on the back and the transparent cover on the front are divided into a plurality of areas, and the reflecting of the concave reflecting mirror that depends on the position of the light beam. Realization of a desired light distribution has been performed by giving the characteristics and the refractive characteristics (lens characteristics) of the transparent cover to each of the divided regions.
However, in the case of the conventional technique just described, the reflection characteristics and the refraction characteristics are designed so that each divided region forms a specific part of the entire light distribution.
For example, the rightmost divided area is in charge of illumination of the rightmost area of the distant light distribution.

On the other hand, in each of the divided deflection function areas (R1, R2,...) In the vehicle headlamp according to the present invention, one of the entire areas where the light distribution described above is performed. A difference is that a function of illuminating a wide area is provided, and a large number of such deflection functional areas are gathered to realize a prescribed light distribution.
Here, one of the reasons why each of the deflection function areas (R1, R2,...) Illuminates a wide area of the area instead of illuminating the entire area where the light distribution is performed. When it is necessary to provide non-uniform brightness in the light distribution, the deflection pattern generation means (Fm) is set so that the darker the portion, the smaller the number of the deflection function regions that illuminate that portion. The design provides the possibility of realizing such a non-uniform light distribution.

The reason why a coherent light beam such as a laser beam may pose a danger to the human eye is that when the light beam directly hits the eye, the area of the light-collecting region formed on the retina is very small. This is because there is a possibility that the optical power density becomes excessive and causes a failure.

In the above-described conventional in-vehicle headlamp, it may be possible to realize the headlamp even if the light source is replaced with a semiconductor laser, for example. In the case of a laser headlamp), as described above, since one divided region of the concave reflecting mirror or the transparent cover is configured to form a specific part of the entire light distribution, The output light beam retains a beam characteristic with strong directivity that reaches far.
Therefore, when it hits the human eye directly, there can be the above-mentioned danger, and this danger is naturally high when it hits nearby, and decreases as it goes farther, but it decreases because of its beam nature. The way is slow with increasing distance.

On the other hand, in the case of the vehicle headlamp according to the present invention, each of the deflection function areas (R1, R2,...) Illuminates a wide area of the entire area where the light distribution of the light distribution described above is performed. Therefore, each output light beam has a strong divergent property and a weak directional beam property as compared with a conventional projector-use laser headlamp, and therefore the power density decreases rapidly as it goes further.
When the output light beam of this in-vehicle headlamp hits the human eye directly, the power from each of the deflection function areas decreases, but the number of the deflection function areas where light enters the pupil (iris diaphragm) is reversed. To increase.
Therefore, if it becomes far beyond a certain level, even if it is a conventional projector-use laser headlamp or the headlamp of the present invention, if it achieves the same distant light distribution, the total power entering the pupil is The same is true, because the distant light distribution achieved is the same).
However, in the case of the headlamp of the present invention, the condensing region formed on the retina is always formed as an aggregate of a plurality of spots, and the optical power is concentrated at one point. It is impossible and safe.

Conversely, if the distance of the eye is closer to the headlamp, the power of light entering the pupil increases in both the conventional projector-use laser headlamp and the headlamp of the present invention, but the conventional projector-use laser In the case of a headlamp, the optical power concentrated on one condensing region formed on the retina simply increases.
On the other hand, in the case of the headlamp according to the present invention, the individual optical power of a plurality of spots constituting the light collection region formed on the retina is increased, and the distance between the spots is set so that The safety is high because it goes away from the proximity of the lighting.

From the viewpoint of improving safety, it is apparent that it is advantageous to reduce the optical power of each spot. For this purpose, the deflection function regions (R1, R2, R2) of the deflection pattern generation means (Fm) are used. It can be readily understood that the number of divisions into (...) should be as large as possible.
For example, assuming that the size of the in-vehicle headlamp of the present invention viewed from the front is 300 mm in the horizontal direction × 100 mm in the vertical direction, the size of the deflection pattern generating means (Fm) is the dimension of the lamp. Assuming that the size of the deflection functional area (R1, R2,...) Is 10 mm × 5 mm, the number of divisions of the deflection pattern generation means (Fm) is 150. It becomes.

Furthermore, from the viewpoint of safety just described, each of the deflection function areas (R1, R2,...) Illuminates a wide area in the entire area where the light distribution of the light distribution described above is performed. In order to provide the possibility of realizing the above-described non-uniform light distribution, it is advantageous that the width when designing is as wide as possible except for the portion discounted from the entire area where the light distribution is performed. Therefore, it should be designed to be at least 40%, preferably 60% or more, and preferably 70% or more with respect to the entire region where light distribution is performed.
In addition, it is desirable to design so that light is delivered from substantially all of the deflection function regions (R1, R2,...) To a portion with the highest illuminance in the light distribution to be formed.

As can be easily understood from what has been described so far, it is clear that the vehicle-mounted headlamp of the present invention and the conventional projector-use laser headlamp have a difference in design philosophy and form. The heightened safety provided by the differences is conspicuous.

Here, in-vehicle headlamps according to the present invention and conventional non-headlight in-vehicle lamps (hereinafter referred to as conventional in-vehicle lamps) such as a vehicle width lamp (position lamp), a tail lamp (tail lamp), and a brake lamp (stop lamp). The relationship with non-headlights for lighting) will be supplemented.
In these conventional in-vehicle non-headlights, the lamp cover is configured as an assembly of a large number of lenses, and each lens functions to convert a light source light beam into a similar divergent light beam. And the deflection function area (R1, R2,...) In the present invention are completely different in operation and purpose.
The above-mentioned conventional vehicle-mounted non-headlamp lamp is intended for information display, and the divergent property is given to make it visible from a wide angle range, not for illumination, The reason for the lens assembly is to improve the visibility by adding a specific glare.

On the other hand, in the case of the in-vehicle headlamp according to the present invention, as described above, although the divergent property is strong and the directional beam property is weak, it is compared with the conventional projector-use laser headlamp. Therefore, the directivity capable of realizing the light distribution required for the headlamp is naturally maintained.
In other words, the present invention can be said to be a technique for reducing dangerous coherency while maintaining the directivity as the in-vehicle headlamp of the present invention. The design philosophy is different from the light.

The danger when the emitted light beam (Bmo) of the headlamp directly hits the human eye is higher as the distance between the headlamp and the eye is shorter. In the case of the headlamp of the present invention, As described above, the individual optical power of a plurality of spots constituting the condensing region formed on the retina increases, and the distance between the spots conflicts with the proximity of the distance between the eye and the headlamp. Therefore, it can be understood that the safety considerations should be considered for the optical power on the retina of one spot.
For this purpose, in each of the deflection function regions (R1, R2,...), The deflection function region in which the area integral of the optical power density irradiated by the light beam (Bu) in the region is maximized is the headlight. Pay attention to the luminous flux output from the lamp.

Then, the illuminance formed by the focused light beam at the closest position where the presence of the human eye is assumed should not exceed the danger level for the human eye.
Regarding the setting of this danger level, for example, it is not necessary to consider the extreme situation where the headlamp is continuously looked into at the closest position where the presence of the human eye is assumed, and exposure to dazzling light However, it may be set at a level that can be protected from eye damage by avoidance behavior that a person naturally performs.
The protection by human avoidance behavior just described is described in JIS C 6802.

The illuminance formed by the light beam deflected by one of the deflection function regions (R1, R2,...) Correlates with the area integral in the deflection function region of the optical power density irradiated by the light beam (Bu). Here, in order to simplify the discussion, a case will be described in which the size of the illumination area (Gu) is predetermined and the area of the deflection function area is defined in order to regulate the above-described illuminance.
The first of the specific methods of designing the headlamp of the present invention so as not to exceed the above-mentioned danger level is the first from the light emitting part (Pmo) to the nearest position where the presence of human eyes is assumed. Assuming that the structure for regulating the distance is predetermined, the area of the deflection function area (R1, R2,...) Is defined so as not to exceed the above-mentioned danger level.
In this case, paying attention to the deflection function region located at the highest illuminance in the illumination region (Gu), the area is determined, and the other illumination regions (Gu) have the same area. Alternatively, the area of the illumination area (Gu) located at a place where the illuminance is high in the illumination area (Gu) is small, and conversely, the place where the illuminance is low in the illumination area (Gu). The area of the illumination area (Gu) located in the area may be increased.

The second way of design is that the area of each of the deflection function regions (R1, R2,...) Is predetermined, and from the light emitting part (Pmo) to the nearest position where the presence of human eyes is assumed. The structure that regulates the distance is defined so as not to exceed the above-mentioned danger level.
In this case, paying attention to the deflection function region where the area integral of the optical power density irradiated by the light beam (Bu) is maximized, the output light beam from the light emission part (Pmo) is human- The distance to the nearest position where the presence of the eye is assumed may be determined, and the above-described regulation structure may be defined so that the other deflection function areas have the same distance, or the optical power described above. The distance may be large for the deflection function area having a large area integral of density, and the distance may be small for the deflection function area having a small area integral of optical power density.

Here, the structure that regulates the distance from the light emitting part (Pmo) to the closest position where the presence of human eyes is assumed is, for example, a transparent glass or plastic that surrounds the light emitting part (Pmo) In the case where the distance is large for the deflection functional region having a large area integral of the optical power density, and the distance is small for the deflection functional region having a small area integral of the optical power density. This can be realized by forming the protective cover with a curved surface.

In the headlamp design of the present invention described so far, paying attention to the optical power incident on one of the deflection function areas, which correlates with the illuminance formed by one of the deflection function areas, A method for ensuring eye safety was described.
At that time, the area of the deflection function area was considered. Since attention is paid to the area integration of the optical power density, it is 1 of the deflection function area with respect to the entire area of the deflection function area (R1, R2,...). The ratio of the individual areas was important, and the conclusion was the same even if the whole area was kept in a similar shape and expanded or reduced.
However, since the headlamp is also an optical device that handles light as electromagnetic waves, it is necessary to pay attention to physical restrictions when designing the headlamp.

For example, ECE R112, which is a standard relating to the light distribution of an in-vehicle headlamp, stipulates that the vertical angle width Θy of Zone I in the low beam light distribution region is 3 degrees. It is understood that it is necessary to have a degree of freedom in which the light distribution can be designed with an angular resolution finer than at least the angular width Θy.

Now, assuming that each of the deflection function areas (R1, R2,...) Is rectangular, for example, one of the deflection function areas (R1, R2,...) That has been irradiated with the light beam (Bu) When attention is paid to the situation where the light distribution is formed at a distance, it is understood that this corresponds to Fraunhofer diffraction formed when the light beam is cut out by a rectangular aperture.
Naturally, a phase distribution can exist in one of the deflection function areas (R1, R2,...) In the headlamp of the present invention, but it is possible to widen the distribution in the distance due to the presence of this. However, if we focus on the limitations of reducing the distribution, it is defined by the size of a simple rectangular aperture where there is no phase distribution.
By the way, “to make the phase distribution exist” as described above is a superordinate concept of operations that cause refraction by a lens, reflection by a curved mirror, diffraction by a non-uniform diffraction grating such as a hologram, etc. Pointed to.

As a preparation for considering the rectangular aperture, a slit whose structure is simplified to one dimension will be described.
When one slit having a width A in the y-axis direction, that is, a single slit extending infinitely in the x-axis direction, is illuminated with a parallel light beam (plane wave) traveling in the z-axis direction with a wavelength λ, the slit is formed by this slit. The power density distribution pattern u (θ) normalized by the central peak value of Fraunhofer diffraction is expressed by the following formula (Formula 1):
u (θ) = [sinc (πAθ / λ)] ^ 2
It is expressed as
Where θ is the angle formed by the direction of the observation point of the power density distribution viewed from the position of the single slit and the z axis, the symbol ^ 2 represents the square operation, and the function sinc is the following equation (Equation 2)
sincφ = sinφ / φ
Represents the sink function defined in.
The specific shape of the u (θ) is as shown in FIG. 8 which is a schematic diagram of the concept related to the in-vehicle headlamp technology of the present invention. A large number of sub-patterns (small local maxima) are arranged on both sides, and a zero value of the distribution can be made for each angle β = λ / A.
The Fraunhofer diffraction pattern having a rectangular opening that is desired to be obtained is obtained by multiplying the single slit diffraction pattern extending in the x-axis direction and the single slit diffraction pattern extending in the y-axis direction orthogonal thereto.
(Reference: Jiro Koyama / Hiroshi Nishihara “Lightwave Electronics”, published on May 15, 1978, Corona, formula (3.53))

Therefore, in order to provide the necessary resolution, the maximum limit of the diffraction pattern size that can be considered to be smaller than Θy including the necessary margin with respect to the vertical angular width Θy of the light distribution desired to be realized is shown in FIG. It is preferable to take the condition that the limit angle width 4β is equal to Θy.
This is because, for example, when the limit angle width is 2β so that the maximum limit of the diffraction pattern size is the size of the main pattern, the maximum of the sub-patterns on both sides is directly outside Θy. This is because it protrudes.
Therefore, the above condition 4β = 4λ / Ay ≦ Θy
The following formula derived from (Formula 3)
Ay ≥ 4λ / Θy
The dimension Ay that defines the diffraction pattern in the vertical direction of the deflection function region may be determined so that the above condition is satisfied (where Θy is in radians).

In the above, the case where each of the deflection function regions (R1, R2,...) Is a rectangle has been considered. However, in the case of a shape other than a rectangle, for example, a triangle, a hexagon, a circle, etc. Although the Fraunhofer diffraction pattern is generated, it is not interesting here about the exact shape of the diffraction pattern, and it is only necessary that the angular size can be approximately defined by the size of the deflection function region. Regardless of the specific shape of the functional area, it is only necessary to handle the above-mentioned conditions, assuming that Ay is a dimension that defines the vertical diffraction pattern of the deflection functional area.
In addition, the size of the deflection function area (R1, R2,...) In the direction corresponding to the lateral direction has not been mentioned so far, but the size in this direction may be neglected. However, in the case of in-vehicle headlamps, the distribution of light distribution to be realized is wide in the horizontal direction, so the restriction on the size of the deflection function area is loose, so the vertical condition should be given priority. Represents.

As a specific value of the condition for Ay, for example, when Θy is 3 degrees which is the angular width of Zone I of the above-mentioned ECE R112, the above-described Expression 3 is calculated.
When λ is 640 nm (R color), Ay ≧ 49 μm,
When λ is 524 nm (G color), Ay ≧ 40 μm,
When λ is 465 nm (B color), Ay ≧ 36 μm
It becomes.

Furthermore, since the headlamp is also an optical device that handles coherent light, it is necessary to pay attention to restrictions on light interference when designing the headlamp.
Now, assuming that each of the deflection function areas (R1, R2,...) Is a rectangle of the same size, output light beams from the N deflection function areas arranged in the x-axis or y-axis direction among them. Think about Fraunhofer diffraction.

In order to simplify the discussion, similarly to the above, the structure is simplified to one dimension, and N slits having a width A as an alternative to the deflection function region are arranged in the arrangement period C. I will think about it.
When this slit row is illuminated with a parallel light beam (plane wave) traveling in the z-axis direction of wavelength λ, the power density distribution pattern p (θ) normalized by the central peak value of Fraunhofer diffraction formed by this slit is The following formula (Formula 4)
p (θ) = [sinc (πAθ / λ)] ^ 2 · F (θ)
It is expressed as
Here, F (θ) is the following formula (Formula 5)
F (θ) = [sin (NπCθ / λ) / sin (πCθ / λ)] ^ 2
This function is expressed by the following equation (Equation 6).
θp = λ / C
A function exhibiting a pulse-train-like pattern that repeats at an angular period calculated in (1), and represents interference fringes in a broad sense.
Then, it is multiplied by the sync function of the same form as the above-mentioned equation 2 to produce p (θ).
Therefore, the power density distribution pattern p (θ) of Equation 4 described above may be a pattern in which the power density distribution pattern u (θ) by the single slit of Equation 1 is divided by a large number of dark lines of interference fringes. I understand.
(Reference: Jiro Koyama and Hiroshi Nishihara “Lightwave Electronics”, published on May 15, 1978, Corona, formula (3.73))

However, in order to apply the consideration regarding the slit row just described to the arrangement of the deflection function regions (R1, R2,...) Of the headlamp, some understanding correction is required.
As shown in FIG. 4, the deflection function areas (R1, R2,...) Are densely arranged and may have the same size and arrangement period, and may block light like a slit. Does not exist.
In response to this, if the width C of the slits constituting the slit row and the period C are made the same, it is no longer a slit row but a blank space.
Therefore, the sinc function appearing in p (θ) of the above-described equation 4 is understood as a (common) Fraunhofer diffraction pattern formed by the phase distribution generated by each of the deflection function regions (R1, R2,...). In addition, it should be understood that the arrangement period C may be equal to the dimension A of the deflection function region.

Further, since the deflection function areas (R1, R2,...) Are not arranged one-dimensionally like a slit row but are arranged two-dimensionally, the entire deflection function areas (R1, R2,...) The Fraunhofer diffraction pattern formed by the emitted light beam (Bmo) from is not a one-dimensional interference fringe but a two-dimensional interference pattern.
Therefore, the arrangement periods θpx and θpy of the interference pattern in the x-axis and y-axis directions are expressed by the following equations θpx = λ / Cx, θpy = λ / Cy
It is expressed as

In the case of the in-vehicle headlamp according to the present invention, if the interference pattern considered here is clearly superimposed in the light distribution, this is not preferable as the headlamp.
However, if the arrangement period of the interference pattern is about the same as or smaller than the angular resolution Ψ of a typical human eye, it will be invisible to the driver and there will be virtually no interference pattern. Become equivalent.
That is, for the arrangement repetition distance C of the deflection function regions (R1, R2,...) That do not distinguish the directions (the x-axis and y-axis directions are combined),
C ≧ λ / Ψ
The deflection functional region (R1, R2,...) May be determined so as to satisfy the above condition (where Ψ is a radian unit).

At this time, as a specific value of the angular resolution Ψ of a typical human eye, it is preferable to set it to 1 minute (1/60 degrees).
Incidentally, the visual acuity is expressed by the reciprocal of the angular resolution expressed in units of minutes, and the above value of 1 minute corresponds to the angular resolution of a person with visual acuity 1.
In addition, when the specific value of the condition for C 1 is given, for example, when the above equation 7 is calculated for the case where Ψ is 1 minute as described above,
When λ is 640 nm (R color), C ≧ 2.2 mm,
When λ is 524 nm (G color), C ≧ 1.8 mm,
When λ is 465 nm (B color), C ≧ 1.6 mm
It becomes.

Here, the meaning of the description “arrangement repetition distance” relating to the arrangement of the deflection function areas (R1, R2,...) Will be supplemented.
This includes the term “repetition”, but this does not require that the alignment of the deflection functional areas (R1, R2,...) Is strictly periodic, and the deflection having the same function. It means the spatial arrangement frequency when a large number of functional areas are arranged with spatial repetition.
Therefore, if the repetition of the arrangement is strictly periodic, the arrangement repetition distance is synonymous with the period.

If it is assumed that the deflection function area is a rectangle and the deflection pattern generation means (Fm) is configured by arranging the deflection function area vertically and horizontally without any gaps, the dimensions of the deflection function area are arranged and the repetition distance.
At this time, the size of the deflection function region is not uniform, and may be small, for example, near the center of the light incident portion (Pmi), and may increase toward the outside in the x-axis or y-axis direction.
Note that the average value of the dimensions of the deflection function area in the x-axis or y-axis direction may be used as the value of the arrangement repetition distance in such a case.

Further, when the average value of the dimensions of the deflection function area is different between the x-axis direction and the y-axis direction, the smaller value may be taken.
The reason for this is that, as apparent from Equation 7, the smaller the arrangement repetition distance, the larger (coarse) the interference pattern arrangement angle, and the easier it is to visually recognize (the conditions are worse). This is because it is reasonable to take the value of.

Also, the deflection function area is not rectangular and the arrangement direction is not 90 degrees apart (x-axis and y-axis directions), for example, the deflection function area is a triangle or hexagon, and the arrangement direction is 60 degrees. The distance may be a direction away from each other. In such a case as well, the value of the repetitive distance may be taken in the direction in which the alignment angle of the interference pattern is the largest.

Considering the limit where N appears infinite in Equation 5 above, it becomes a diffraction grating. For example, in the case of a diffraction grating used in a spectroscopic device, the better the periodicity, the more repeated pulses in Equation 6 above. Since the width is narrow and clear, the spectral resolution is improved and it is said to be a good diffraction grating.
As described above, in the case of the in-vehicle headlamp according to the present invention, if the interference pattern is clearly superimposed in the light distribution, this is not preferable as the headlamp. It can be seen that if the conditions of the diffraction grating for the device are reversed and the periodicity is deteriorated, the interference pattern becomes unclear and the quality as the headlamp for in-vehicle use is improved.
That is, the arrangement may be modulated so as to give a disturbance to the periodicity of the arrangement of the deflection function regions (R1, R2,...). For example, random disturbance modulation is preferable.

The deflection pattern generation means (Fm) described so far is for deflecting and emitting each incident light beam incident on the light incident portion (Pmi). Is dependent on the incident position of the light beam in the light incident portion (Pmi), and the dependency, that is, the distribution in the light incident portion (Pmi) with respect to the direction of deflection given is the desired distribution. It must be designed to be

The deflection pattern generating means (Fm) capable of realizing this is preferably constituted by an optical element having a light reflecting surface whose normal line direction changes depending on the position in the light incident portion (Pmi). .
At the time of production, low-cost methods such as press molding of metal plates and reflection film coating on plastic injection molded products can be used.
In the case of the deflection pattern generating means (Fm), the light incident part (Pmi) also serves as the light emitting part (Pmo).

The deflection pattern generating means (Fm) is preferably constituted by an optical element having a photorefractive medium whose thickness or refractive index changes depending on the position in the light incident part (Pmi).
In this case, in the case of a photorefractive medium having a variable thickness, the deflection pattern generating means (Fm) includes a light incident side refracting surface (Pmi) and a light emitting portion (Pmo). It is a lens in a broad sense having a certain light exit side refractive surface.
For example, if the refracting surface on the light exit side is a flat surface, the refracting surface on the light incident side is a curved surface, and the normal direction of this curved surface changes depending on the position at the light incident portion (Pmi). What is necessary is just to comprise as a curved surface.
For production, a low-cost method such as plastic injection molding can be used.

Further, it is preferable that the deflection pattern generating means (Fm) is constituted by a diffraction grating having an interference fringe whose phase changes depending on the position in the light incident portion (Pmi), that is, a hologram.
At this time, the type of the diffraction grating is preferably a phase type with high diffraction efficiency, that is, a refractive index modulation type, and more preferably a volume type diffraction grating.
The diffraction grating may be a transmissive type in which diffracted light is output from the back side of the light incident surface, or a reflective type in which the diffracted light is output from the light incident surface.
In addition, since the function of the diffraction grating is sensitive to the light wavelength, it is difficult to produce a high diffraction efficiency even when white light mixed with R, G, B (red, green, and blue) is incident. There is a case.
In order to avoid this problem, the deflection pattern generation means (Fm) is formed separately for each of R, G, and B, and the illumination area (Gu) is separated for each of R, G, and B. It is preferable to irradiate the diffraction grating for each color separately (hereinafter referred to as a color separation diffraction grating illumination method) and deflect the light to generate an emitted light beam (Bmo). .

Next, a description will be given with reference to FIG. 5 which is a schematic diagram showing a part of the vehicle headlamp of the present invention in a simplified manner.
In the figure, a plurality of deflection pattern generating means (Fm, Fm ′, Fm ″,...) Having different light distributions are integrally configured so as to occupy different positions in the light incident part (Pmi). It is drawn.
For example, the deflection pattern generation means (Fm, Fm ′, Fm ″,...) Is based on a planar base material, and the light reflecting surface region where the normal direction changes, or the thickness or refractive index described above. Or a diffraction grating region having an interference fringe whose phase changes as described above (in the case of a photorefractive medium whose reflection surface or thickness changes, irregularities are formed).
Then, one of the deflection pattern generation means is selected from the deflection pattern generation means (Fm, Fm ′, Fm ″,...), And the illumination pattern (Gu) is positioned in the vicinity thereof. The relative positional relationship between the generation means (Fm, Fm ′, Fm ″,...) And the illumination area (Gu) can be changed.
In order to change the relative positional relationship between the deflection pattern generation means (Fm, Fm ′, Fm ″,...) And the illumination area (Gu), for example, a deflection pattern generation means moving mechanism (not shown) And the deflection pattern generating means (Fm, Fm ′, Fm ″,...) May be translated in the direction of the arrow (A).

Alternatively, this figure is interpreted as a development of a prismatic surface or a cylindrical surface, and the prismatic surface or the cylindrical surface has a central axis parallel to the horizontal direction of the figure, and the prismatic surface or You may comprise so that a cylindrical surface may be rotated and the above-mentioned light reflective surface area | region or photorefractive medium area | region and diffraction grating area | region built in the base material may be selected.
Further, a planar base material is formed into a disk shape (not shown), and can be rotated around an axis perpendicular to the base material surface. You may comprise so that a photorefractive medium area | region and a diffraction grating area | region may be selected.

Here, as an example of a change in the relative positional relationship between the deflection pattern generation means (Fm, Fm ′, Fm ″,...) And the illumination area (Gu), the deflection pattern generation means moving mechanism is The configuration for moving the deflection pattern generation means (Fm, Fm ′, Fm ″,...) Has been described. Conversely, the light projection is performed with the deflection pattern generation means (Fm, Fm ′, Fm ″,...) Fixed. The optical system (Eu) and the preceding optical system are moved, or the deflection pattern generation means (Fm, Fm ′, Fm ″,...) And the light projection optical system (Eu) and Both of the preceding optical systems may be fixed, and a movable mirror may be inserted between them, and the deflection pattern generating means moving mechanism may be configured to change the angle and position of the movable mirror.

As described above, by selecting the plurality of deflection pattern generation means (Fm, Fm ′, Fm ″,...) Having different light distributions and irradiating the light beam (Bu), the high beam distribution is achieved. It can be realized by switching light distribution, low beam light distribution, or other light distribution.

In the in-vehicle headlamp of the present invention described with reference to FIG. 5, any one of the plurality of deflection pattern generating means (Fm, Fm ′, Fm ″,...) Having different light distributions is selected and operated. It was.
Further improving this, the deflection pattern generating means (Fm, Fm ′, Fm ″,...) Are arranged close to each other so that there is substantially no gap between them. As shown in FIG. 6, which is a schematic diagram showing a part of the illumination lamp, a setting in which the illumination region (Gu) is located at an intermediate position between two adjacent ones of the deflection pattern generation means. It is preferable to configure the deflection pattern generating means moving mechanism so as to be possible.
In this way, it is possible to form an intermediate light distribution with respect to the light distribution formed by each of the two deflection pattern generation units.

Now, paying attention to the deflection pattern generation means (Fm) and the deflection pattern generation means (Fm ′), the center line of the illumination area (Gu) is the center line (Lc) of the deflection pattern generation means (Fm). When it is above, in the first light distribution state in which the light distribution of the deflection pattern generation means (Fm) is 100%, the center line of the illumination area (Gu) is the center of the deflection pattern generation means (Fm ′). When it is on the center line (Lc ′), the second light distribution state is realized in which the light distribution of the deflection pattern generation means (Fm ′) is 100%.
And the synthetic | combination ratio of an above described 1st light distribution state and a 2nd light distribution state is continuously adjusted with the distance (d) from the said center line (Lc) of the center line of the said illumination area | region (Gu). The light distribution state can be set.

By utilizing this function, for example, an intermediate light distribution between the low beam distribution and the high beam distribution can be realized without increasing the number of deflection pattern generation means, or the low beam distribution can be realized. It is also possible to gradually switch from a light distribution to a high beam light distribution.

The in-vehicle headlamp of the present invention having the function described with reference to FIG. 5 or FIG. 6 has a light quantity of the emitted light beam (Bmo) according to the selected / set light distribution state. It is preferable to provide a function that enables setting.
In order to realize this, an integrated control circuit (Ux) that controls the power supply circuit (Ps) to determine the input power to the light emitting element (Sc) is provided, and the integrated control circuit (Ux) Recognizing the relative positional relationship between the generating means (Fm, Fm ′, Fm ″,...) And the illumination area (Gu), the power input to the light emitting element (Sc) is set according to the recognition information. What is necessary is just to comprise so that the said electric power feeding circuit (Ps) may be controlled.

By doing so, for example, when switching to a light distribution with a wide illumination range such as a high beam, it is possible to avoid a phenomenon such as insufficient short-distance illuminance.

Here, the integrated control circuit (Ux) may control the deflection pattern generating means moving mechanism based on the recognition information, or conversely, the light distribution state set by the deflection pattern generating means moving mechanism. May be read and recognized by the integrated control circuit (Ux).

In FIG. 4 referred to above, for the sake of simplicity, the light emitting element (Sc) is used as a light source. However, in order to obtain a practical in-vehicle headlamp, an emitted light beam of white light is used. It is necessary to realize.
In addition to the white light generated by providing a coherent light source of the three primary colors R, G, and B as will be described later, for example, the phosphor is excited by using a semiconductor laser that emits B-color coherent light. The original B color that is not converted to incoherent light, which is mixed with the incoherent light mixed with the color or incoherent light having the Y (yellow) peak spectrum when mixed. The present invention can also be applied to white light obtained by mixing components and these incoherent lights.
When only some of the colors are coherent, the area condition of the deflection function region (R1, R2,...) Based on the viewpoint of protection from the above-described eye damage, or the above-described typical As for the condition of Equation 7 based on the comparison between the angular resolution Ψ of a human eye and the arrangement period of interference patterns, it is sufficient to satisfy only the color in which the light is coherent.

FIG. 7 is a schematic diagram showing a part of the vehicle headlamp according to the present invention in a simplified manner with respect to an embodiment in which white light is generated by providing a coherent light source of three primary colors of R, G, and B in the following. The description will be given with reference.
The light emitting elements (Sc1, Sc1 ′,..., Sc2, Sc2 ′,...) Built in the element light sources (U1, U2,...) Respectively provided corresponding to the R, G, B wavelength bands are Driven by driver circuits (P1, P1 ′,..., P2, P2 ′,...) Of the power feeding circuit (Ps) to emit light.
For each of the light emitting elements (Sc1, Sc1 ′,..., Sc2, Sc2 ′,...), Here, for example, the semiconductor laser or the radiated light of the semiconductor laser is used as a harmonic generation / optical parametric effect or the like. A light source that performs wavelength conversion using a non-linear optical phenomenon, and a plurality of such coherent light sources are connected in series, in parallel, or in series-parallel, and so on. , P1 ′,..., P2, P2 ′,.

In addition, the driver circuits (P1, P1 ′,...) Here are DC / DC converters configured by a circuit of a method such as a step-down chopper or a step-up chopper, which is fed by a direct current power source (not shown). It is assumed that specified power can be input to the light emitting elements (Sc1, Sc1 ′,...).
The integrated control circuit (Ux) is provided for each driver circuit (P1, P1 ′,..., P2, P2 ′,...) Via driver circuit control signals (J1, J1 ′,..., J2, J2 ′,...). Each of the light emitting elements (Sc1, Sc1 ′,..., Sc2, Sc2 ′,...) Can be supplied with specified power and controlled individually.
Further, the integrated control circuit (Ux) controls the deflection pattern generation means moving mechanism (Ms) via the position designation signal (Jm), and sets the position of the deflection pattern generation means (Fm).

The light emitted from the light emitting elements (Sc1, Sc1 ′,..., Sc2, Sc2 ′,...) For each of the R, G, and B wavelength bands of the element light sources (U1, U2,. The light is condensed on the incident end (Ei1, Ei2,...) Of the optical fiber (Ef1, Ef2,...) By the condensing optical system (Ec1, Ec2,...) And propagates through the core of the optical fiber (Ef1, Ef2,. Thus, the light is emitted from the emission end (Eo1, Eo2,...).
Align the exit ends of the optical fibers (Ef1, Ef2,...) So that the exit ends (Eo1, Eo2,...) Are located on the same plane and bundle the exit ends of the optical fibers (Ef1, Ef2,...). Thus, the light emission region (Gs) can be realized.
The radiated light from the exit ends (Eo1, Eo2,...) Are combined to form one output light beam and output as the light beam (Bs). For example, the light projection optical system (FIG. 4) It enters an optical system consisting of Eu) and subsequent parts.

Here, the light of each color of R, G, and B is described as being transmitted by the three optical fibers (Ef1, Ef2,...), But this may be transmitted by one optical fiber. Good.
However, when realizing the above-described color separation diffraction grating illumination system, light of each color R, G, B is transmitted through the three optical fibers (Ef1, Ef2,...) And then the optical fiber (Ef1). , Ef2,...) Need not be bundled.

A few supplements regarding the optical system design.
As is generally known in the lens design field, an optical system consisting of a single lens is structurally converted to an optical system consisting of a combination of multiple lenses having the same function, or the reverse structural conversion is performed. In particular, in the former structural transformation, even if the focal length of the target optical system is the same, the input principal point position and the output principal point position can be set to convenient positions, or an afocal system is introduced. To achieve functions that are physically unrealizable with a single lens, or to reduce aberrations by distributing the lens power to multiple lenses. .

The present invention can be used in an industry for designing and manufacturing an on-vehicle headlamp using a light emitting element such as a semiconductor laser.

A arrow Bmo exiting light beam Bs light beam Bu light beam Ci bottom surface d distance Ec1 condensing optical system Ec2 condensing optical system Ef1 optical fiber Ei2 incident end Ei2 incident end Eo1 exit end Eo2 exit end Eu light projection optical system Fm deflection pattern generation Means Fm 'Deflection pattern generation means Fm "Deflection pattern generation means Gs Light emission area Gu Illumination area J1 Driver circuit control signal J1' Driver circuit control signal J2 Driver circuit control signal J2 'Driver circuit control signal Jm Position designation signal Ks Radiation surface element Ks' Radiation surface element Lc Center line Lc 'Center line Lms1 Peripheral ray Lms2 Peripheral ray Lps Main ray Lps' Main ray Mps Deflection pattern generating means moving mechanism P1 Driver circuit P1' Driver circuit P2 Driver circuit P2 'Driver circuit Pm i light incident part Pmo light emitting part Ps feeding circuit Qs point R1 deflection functional area R2 deflection functional area Sc light emitting element Sc1 light emitting element Sc1 ′ light emitting element Sc2 light emitting element Sc2 ′ light emitting element U1 element light source U2 element light source Ux integrated control circuit

Claims (11)

1. A light emitting element (Sc) that emits coherent light;
   A power feeding circuit (Ps) for driving the light emitting element (Sc);
   Light projection having a light emission region (Gs) formed by light from the light emitting element (Sc) and projecting the light from the light emission region (Gs) to form a prescribed shape illumination region (Gu) An optical system (Eu);
   Installed in the vicinity of the illumination area (Gu), each incident light beam incident on it is deflected and emitted, and converted into an emitted light beam (Bmo) having a prescribed light distribution that illuminates a distant area. A vehicle-mounted headlamp comprising a deflection pattern generating means (Fm) for
   The deflection pattern generating means (Fm) is configured such that the light incident portion (Pmi) is divided into a large number of deflection function regions (R1, R2,...) And is incident on the light incident portion (Pmi). When each of the incident light beams is deflected and emitted, the direction of deflection to be applied is configured to depend on the incident position of the light beam in the light incident portion (Pmi), and the deflection function area (R1, R1). R2, ...) each illuminates a wide area of the entire area where the light distribution of the light distribution described above is performed.
2. The illuminance formed by the light beam deflected by one of the deflection function areas (R1, R2,...) At the closest position where the presence of the human eye is assumed is natural for a human to be exposed to dazzling light exposure. The optical power incident on each of the deflection function regions (R1, R2,...) Is defined so as to be less than or equal to a level that can be protected from eye damage by the avoidance action to be performed. Automotive headlamp.
3. The size of the deflection functional region (R1, R2,...) In the direction corresponding to the vertical direction of the emitted light is such that the angle distribution Θy in the radians in the vertical direction of the light distribution described above and the light emitting element ( The following value calculated by the wavelength λ of the radiated light of Sc): Aymin = 4λ / Θy
   It is the above, The vehicle-mounted headlamp of Claim 1 characterized by the above-mentioned.
4. Next, the alignment repetition distance of the deflection functional regions (R1, R2,...) Is calculated by the angular resolution Ψ in radians of a typical human eye and the wavelength λ of the emitted light of the light emitting element (Sc). Value of Cmin = λ / Ψ
   It is the above, The vehicle-mounted headlamp of Claim 1 characterized by the above-mentioned.
5. The in-vehicle headlamp according to claim 1, wherein the arrangement is modulated so as to give a disturbance to the arrangement periodicity of the deflection function areas (R1, R2, ...).
6. In order to realize that the above-described deflection direction depends on the incident position of the light beam at the light incident portion (Pmi), the deflection pattern generation means (Fm) has a normal direction depending on the position. The in-vehicle headlamp according to claim 1, comprising a light reflecting surface that changes.
7. In order to realize that the above-described deflection direction depends on the incident position of the light beam at the light incident portion (Pmi), the deflection pattern generation means (Fm) has a thickness or a refraction depending on the position. The in-vehicle headlamp according to claim 1, wherein the headlamp is configured by a photorefractive medium whose rate changes.
8. In order to realize that the above-described deflection direction depends on the incident position of the light beam at the light incident portion (Pmi), the deflection pattern generating means (Fm) changes its phase depending on the position. The in-vehicle headlamp according to claim 1, comprising a diffraction grating having interference fringes.
9. The deflection pattern generation means includes a plurality of deflection pattern generation means (Fm, Fm ′,...) Having different light distributions, and selects any one so that the illumination area (Gu) is positioned in the vicinity thereof. The in-vehicle headlamp according to claim 1, wherein a relative positional relationship between (Fm, Fm ', ...) and the illumination area (Gu) can be changed.
10. A plurality of the deflection pattern generation means (Fm, Fm ′,...) Having different light distributions are arranged close to each other, and the deflection pattern generation means (Fm, Fm ′,...) And the illumination area (Gu) Is the intermediate position between two adjacent ones of the deflection pattern generation means, the light distribution distribution formed by each of the two deflection pattern generation means is independent. The in-vehicle headlamp according to claim 9, wherein a combined light distribution is formed.
11. It further includes an integrated control circuit (Ux) that controls the power feeding circuit (Ps) to determine the input power to the light emitting element (Sc), and the integrated control circuit (Ux) includes the deflection pattern generation means (Fm, Fm ′,...) And the illumination area (Gu) are recognized, and the relative position between the deflection pattern generating means (Fm, Fm ′,...) And the illumination area (Gu) is recognized. The in-vehicle headlamp according to claim 9 or 10, wherein the power feeding circuit (Ps) is controlled so as to change an input power to the light emitting element (Sc) according to a relationship.

Images