JP2006040707A - Light beam irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light beam irradiation device capable of displaying various information by heightening visibility without enlarging the device. <P>SOLUTION: The light beam emitted from a laser light source 4 is split into reflection light L1 and transmission light L2 at a semi-permeable film 10a arranged on a first beam splitter 5. The transmission light is successively split into reflection light L1 and transmission light L2 same as the above by successively arranging beam splitters 6 to 9 in a travelling direction of the transmission light L2. A reflection mirror 11 is arranged under the last beam splitter 9 to reflect the light. The light beam is reflected in one direction by the respective semi-permeable films and the reflection mirrors, and deflected and irradiated outward by galvano-mirrors 13 to 18. The espective galvano-mirrors are electrically connected to a control means 19, and deflection angle is adjusted in advance. The diameter of the light beam is expanded by arranging a beam expander 20 between the light source 4 and the beam splitter 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light beam irradiation apparatus that divides a light beam and irradiates the light beam as a plurality of light beams. For example, the existence of the own vehicle is informed to others and other vehicles, or the course of the own vehicle is driven The present invention relates to a light beam irradiation apparatus used in a vehicle driving support apparatus that irradiates a light beam onto a road surface such as a road in order for a person to grasp.

Conventionally, as a vehicle driving support device that irradiates a light beam onto the road surface of a road and indicates the course and presence of the host vehicle to the driver of the host vehicle, other vehicles, pedestrians, etc. It is disclosed. This vehicle driving support apparatus includes a beam irradiator, and the beam irradiator includes a beam generator made of a semiconductor laser, a beam shaping lens, a deflection shaper, and a scan actuator. The scanning actuator is driven by a command from the beam electronic control unit to scan the light beam and irradiate it in a visible state.
The vehicle driving support apparatus has four beam irradiators, and is provided, for example, on the left and right sides of the front part of the vehicle and the left and right sides of the rear part of the vehicle. The pattern of the light beam emitted by the beam irradiator has the same optical characteristics as the light beam. The light control means mounted on the vehicle driving support device makes light having the same optical characteristics as the light beam easier to transmit than light having other optical characteristics.
According to this apparatus, when a light beam having predetermined optical characteristics is irradiated onto a road surface around a vehicle, a light beam pattern is formed on the road surface. For example, when the vehicle goes straight, this pattern is irradiated linearly forward in the traveling direction on both sides along the vehicle width, and when turning, it is irradiated in a substantially arc shape along the maximum turning width of the vehicle. Will be.
JP 2003-285658 A

However, in the above-mentioned vehicle driving support device, the light on the road surface is irradiated by scanning one light beam with the scan actuator, so the pattern on the road surface becomes a simple continuous line, and other vehicles, pedestrians, etc. The information given to will be limited. Moreover, in order to form a pattern on the road surface by scanning the light beam when the vehicle is traveling, the light beam is moved at a certain speed. Therefore, the pattern formed on the road surface increases as the scanning speed increases. There is a problem that visibility is lowered.
In this case, by providing a plurality of beam generators and individually irradiating the light beam, the information that can be displayed can be diversified and the visibility can be improved. However, since the apparatus is enlarged, it is not suitable for mounting on a vehicle or the like. It was.
In view of such circumstances, an object of the present invention is to provide a light beam irradiation apparatus that can display various information with high visibility without increasing the size of the apparatus.

The light beam irradiation apparatus according to the present invention includes a light source that irradiates a light beam, a plurality of light beam splitting units that branch the incident light beam into reflected light and transmitted light and that are arranged in the traveling direction of the transmitted light, and the light And a deflector having a variable deflection direction for deflecting each of the light beams reflected by the beam splitting means.
According to the present invention, the light beam emitted from the light source is split into reflected light and transmitted light by the first light beam splitting means, the reflected light is directed to the deflector, and the transmitted light is reflected by the second light beam splitting means. Divided into light and transmitted light, the reflected light goes to the deflector. The plurality of reflected lights are reflected in a desired direction by a deflector set in advance at a desired deflection angle, and are irradiated to the outside.
Of the plurality of light beam splitting means, the one set at the end in the traveling direction of the transmitted light may set the light beam transmittance to zero. Thus, the last light beam splitting means becomes a reflecting means for total reflection, and the light beam can be used as irradiation light without waste. According to this light beam irradiation apparatus, the light beam can be divided into a plurality of parts and individually controlled to reduce the size of the apparatus and display various information with high visibility by irradiation. For example, by irradiating the reflected light beams as light spots that are separated from each other, the visibility becomes higher than that of continuous light beams.

In the light beam irradiation apparatus of the present invention, it is preferable that the deflector is disposed in one direction with respect to the plurality of light beam splitting means.
A plurality of light beams reflected by the plurality of light beam splitting means can be irradiated in one external direction via a deflector. Thereby, a light spot pattern can be formed.
Alternatively, in the light beam irradiation apparatus of the present invention, the deflector is arranged in a plurality of directions with respect to the plurality of light beam dividing means, and the light beam dividing means arranges the reflected light in the plurality of directions. The light beams that are selectively reflected and deflected by the deflectors arranged in a plurality of directions may be emitted in different directions.
The light beam emitted from the light source is split into reflected light and transmitted light by the first light beam splitting means, and the transmitted light is sequentially split into reflected light and transmitted light by the second and subsequent light beam splitting means, The light beams respectively reflected by the plurality of light beam splitting means are selectively propagated in different directions and deflected by the deflector, so that the light beams are directed to the outside as being directed in a plurality of directions.
According to this light beam irradiation apparatus, the light beam emitted from the light source can be branched and irradiated as light beams directed in a plurality of directions, so that an effect equivalent to that provided by a single apparatus can be exhibited. .
In this case, the light beams reflected by the plurality of light beam splitting means may be alternately reflected in two directions. For example, the odd-numbered reflected light and the even-numbered reflected light can be reflected in different directions by a plurality of light beam splitting means, and each can be irradiated as a light spot pattern via a deflector.

Further, at least one of the light beams reflected by each of the plurality of light beam splitting units may be configured to reflect at an acute angle with respect to the optical axis of the light beam incident on the light beam splitting unit.
Alternatively, the light beam splitting means may be configured such that a plurality of light beams reflected in the same direction are gathered toward the deflector.
A light beam irradiating apparatus that can collect a light beam by reflecting a part or all of a plurality of reflected lights at an acute angle, and can deflect the light beam with a small deflector such as a MEMS mirror provided in a narrow region. Can be miniaturized. If all the reflected light is reflected at an acute angle, the deflector can be arranged closer to the light beam splitting means, and the light beam irradiation apparatus can be miniaturized.

The plurality of light beam splitting means may have different reflectivities, and the intensity of the light beam emitted through the deflector can be adjusted.
In particular, the plurality of light beam splitting means are preferably set so that the reflectance gradually increases in the traveling direction of the transmitted light.
The light beam emitted from the light source is divided into reflected light and transmitted light by the light beam splitting means, and the transmitted light is further divided into reflected light and transmitted light, so that the light is directed toward the traveling direction of the transmitted light beam. By setting the reflectance of the beam splitting means to gradually increase, the intensity of the plurality of light beams emitted through the deflector can be set to be nearly equal.
The light beam splitting means is arranged in N (N = 1, 2,...) In the traveling direction of the transmitted light beam, and reflected by the nth (n = 1, 2,..., N) light beam splitting means. When the rate is Rn and the transmittance is Tn, it is preferable to satisfy the following formulas (1) to (3).
0.5 / N ≦ R1 <1.5 / N (1)
Tn = 1−Rn (2)
0.7 × Rn ₋₁ / Tn ₋₁ <Rn <1.3 × Rn ₋₁ / Tn ₋₁ (3)
By controlling within the range of the above formulas (1) to (3), it is possible to divide the light beam and transmitted light emitted from the light source and balance the intensity of the emitted light for the reflected light.

The light beam splitting unit is formed by bonding a plurality of triangular prisms, and a split surface is preferably provided on the bonding surface, and the light beam is split into reflected light and transmitted light on the split surface. Therefore, the deflection direction of the reflected light can be set according to the angle of the dividing surface with respect to the light beam. By integrating the prisms together, the configuration is simplified and adjustment is facilitated.
Further, the plurality of triangular prisms may be shifted alternately and have different apex angles arranged to face each other.
By providing a split surface on the slope that forms the apex angle of each triangular prism, the direction of the reflected light can be set by directing the reflected light in one direction or alternately in two directions. At that time, by changing the size of the apex angle, the angle of the dividing surface with respect to the optical axis of incident light or transmitted light is different, and reflected light in the same direction can be collected. As a result, a plurality of deflectors can be set in a narrow range and can be miniaturized.
At this time, the length of the bonding surface may be different in the longitudinal sectional view of the light beam splitting means.
Further, the light beam splitting means may be formed by bonding parallelogram prisms, and a split surface may be provided on the bonding surface.
Further, the light beam splitting means may be a plate-like half mirror, which is less expensive than when a prism is used.

The polarizer may be connected to control means for controlling the deflected light beam to a desired deflection angle.
The attitude of the deflector may be biaxially controlled by the control means. For example, the light beam incident on the deflector is controlled to a desired deflection angle by setting the deflector so as to be rotatable about the X axis and the Y axis orthogonal to each other. be able to.
Further, it is preferable that a light beam shaping means for adjusting a light beam diameter of the light beam is disposed between the light source and the light beam splitting means.
When the light beam is emitted through the deflector, if the irradiation distance becomes long, the diameter of the light beam increases due to the influence of diffraction. The influence can be suppressed.
The light beam shaping means may be a beam expander.
In addition, the light beam transmitted through the light beam shaping means may be convergent light or divergent light. Therefore, an optical element having a power such as a lens is disposed immediately after the light beam shaping means, so that convergent light or divergent light is provided. Can be formed into light.

  According to the light beam irradiation apparatus of the present invention, since the light beam can be divided into a plurality of parts and individually controlled, various information can be displayed with high visibility by irradiation. In addition, the size of the apparatus is not increased by dividing the light beam and irradiating it.

Hereinafter, a vehicle driving support apparatus including a light beam irradiation apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.
1 to 5 show a light beam irradiation apparatus according to the first embodiment. FIG. 1 is a perspective view of a vehicle equipped with the light beam irradiation apparatus. FIG. 2 shows an optical system of the light beam irradiation apparatus. FIG. 3 is a plan view of FIG. 2, FIG. 4 is a diagram showing a beam expander, and FIG. 5 is a diagram showing the relationship between the transmittance, reflectance, and light intensity of the beam splitter.
In FIG. 1, light beam irradiation devices 2 and 2 are mounted on both sides of the upper part of the windshield in the vehicle 1. Although not shown, the light beam irradiation devices 2 and 2 are also provided on both upper sides of the rear glass in the vehicle 1.
Next, the optical system of the light beam irradiation apparatus 2 will be described with reference to FIGS.
The light beam irradiation device 2 includes, for example, a light source 4 composed of a second harmonic of a YAG laser, and a first beam splitter 5 (light beam) that splits a light beam L emitted from the light source 4 into reflected light L1 and transmitted light L2. Dividing means). Further, second, third, fourth, and fifth beam splitters 6, 7, 8, and 9 (light beam dividing means) are sequentially arranged following the first beam splitter 5 in the traveling direction of the transmitted light L2. .
Each of the beam splitters 5 to 9 has a substantially quadrangular prism shape in which the slopes (bottom surfaces) 10a and 10a of the two triangular prisms 10 and 10 are joined. On one inclined surface 10a, a semi-transmissive film 10b (divided surface) that divides the incident light beam L into reflected light L1 and transmitted light L2 is formed. The semi-transmissive film 10b is configured by applying a half mirror coating made of a dielectric multilayer film or a metal film.

A plate-like reflecting mirror 11 is disposed in the traveling direction of the light beam L2 that passes through the fifth beam splitter 9, and this transmitted light beam L2 is directed in the same direction as the reflected light L1 from the beam splitters 5-9. Reflect.
Galvano mirrors 13, 14, 15, 16, 17, and 18 (polarizers) that can be tilt-driven in arbitrary directions are provided in the traveling direction of the light beam L 1 reflected by the beam splitters 5 to 9 and the reflection mirror 11. They are provided facing each other. Each of the galvanometer mirrors 13 to 18 is electrically connected to a control circuit 19 (control means). Upon receiving a signal from the control circuit 19, the galvanometer mirrors 13 to 18 are arbitrarily arranged around, for example, two axes in the X axis direction and the Y axis direction orthogonal to each other It can be rotated at an angle.
For example, assuming that the traveling direction of the vehicle 1 is the A direction in FIG. 2, the light beam L <b> 1 reflected by the galvanometer mirrors 13 to 18 is emitted in the A direction as an irradiation beam. In the example shown in FIG. 2, the light beams L1 reflected and deflected by the galvanometer mirrors 13 to 18 travel substantially in parallel, but can also be traveled in a direction in which they are diffused or gathered by the control circuit 19. .
In the present embodiment, the semi-transmissive films 10b and the reflecting mirrors 11 of the beam splitters 5 to 9 and the galvanometer mirrors 13 to 18 are arranged substantially parallel to each other. In addition, the reflected light from each of the beam splitters 5 to 9 and the reflecting mirror 11 is arranged so as to be reflected substantially at right angles to the light beams L and L2, which are incident light, and directed toward the galvanometer mirrors 13 to 18. Has been.

A beam expander 20 (beam shaping means) for shaping the beam diameter of the light beam L emitted from the light source 4 is disposed between the light source 4 and the first beam splitter 5. A plurality of irradiation beams L1 emitted from the light beam irradiation device 2 are avoided by irradiating the laser beam from the light source 4 as it is, for example, on a road surface 30 meters ahead, because the beam diameter becomes thick due to diffraction. Therefore, the beam diameter is expanded in advance by the beam expander 20.
An example of the beam expander 20 is shown in FIG. FIG. 4A shows a beam expander 20 employed in a Galileo telescope. The light beam L transmitted through the plano-concave lens 21 and the plano-convex lens 22 is expanded in diameter from D2 to D1, and is a parallel beam. become. A similar transmission beam expander 20 is used in the Kepler telescope shown in FIG. Further, as a reflection type beam expander, as shown in FIG. 4 (c), a light beam that has been expanded and reflected by a convex mirror is reflected by a concave mirror into a parallel light beam, or as shown in FIG. 4 (d). For example, two concave mirrors are arranged to face each other to expand the beam diameter to obtain a parallel light flux.

Here, in the light beam irradiation apparatus 2, assuming that the reflection mirror 11 is a beam splitter having zero transmittance, all the arranged beam splitters 5 to 9 and 11 are N in the traveling direction of the light beam L or the transmitted light L2. (N = 1, 2,...) Are arranged. Then, assuming that the reflectance at the semi-transmissive film 10b of the n-th (n = 1, 2,..., N) beam splitter is Rn and the transmittance is Tn, the reflectance Rn and the transmittance Tn of each beam splitter are as follows. It is preferable to satisfy the formulas (1) to (3).
0.5 / N ≦ R1 <1.5 / N (1)
Tn = 1−Rn (2)
0.7 × Rn ₋₁ / Tn ₋₁ <Rn <1.3 × Rn ₋₁ / Tn ₋₁ (3)
If the reflectance Rn is within the ranges of the above formulas (1) and (3), the intensity of the plurality of reflected lights L2 can be balanced. In addition, within the range of the expression (3), it is possible to control that the beam diameter is expanded due to the influence of diffraction and the luminance of the light spot is changed. Note that the reflection mirror 11 is not included in the expression (3).

The light beam irradiation apparatus 2 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.
2 and 3, the light beam L emitted from the laser light source 4 is shaped by the beam expander 20 so that the diameter of the light beam L is a desired size. The light beam L that has passed through the beam expander 20 enters the first beam splitter 5 as a parallel beam.
In the first beam splitter 5, the light beam L is branched into the reflected light L1 and the transmitted light L2 at a preset ratio by the semi-transmissive film 10b provided on the inclined surface 10a. The reflected light beam L1 enters the first galvanometer mirror 13. Since the first galvanometer mirror 13 is set at a desired angle in the horizontal direction (X-axis direction) and the vertical direction (Y-axis direction) by the control circuit 19, the light beam L1 is reflected at a desired deflection angle to generate light. Injected outside the beam irradiation device 2. The light beam L1 is emitted in the direction A, which is the traveling direction of the vehicle 1, and is irradiated as a light spot at a desired position on the road surface.
On the other hand, the light beam L2 that has passed through the first beam splitter 5 repeats the same action in the second to fifth beam splitters 6, 7, 8, and 9, and sequentially turns into the reflected light L1 and the transmitted light L2 at a set ratio. Branch off. Then, each reflected light beam L1 is reflected at a desired reflection angle by the galvanometer mirrors 14, 15, 16, and 17, respectively, and is emitted in the direction A outside the light beam irradiating device 2, and is emitted to a desired position on the road surface. Irradiated as a spot. Further, the transmitted light transmitted through the fifth beam splitter 9 is incident on the reflection mirror 11 at an incident angle of 45 °, for example, and is totally reflected at a substantially right angle, and is reflected by the sixth galvanometer mirror 18 in the same manner as the galvanometer mirrors 13 to 17 described above. Then, the road surface is irradiated to form a light spot.
In FIG. 2, the light beam L1 reflected by the galvanometer mirrors 13 to 18 may interfere with the beam splitters 5 to 9 in the traveling direction shown in the figure, but the light beam L1 is shifted in a direction perpendicular to the paper surface. Interference can be prevented.

For example, when the vehicle 1 travels straight, the light spot group irradiated on the road surface is arranged in two straight lines at intervals similar to the vehicle width of the vehicle 1 as shown in FIG. The light spot patterns La and La are formed. The light spot pattern La formed by one light beam irradiation device 2 is formed with light spots on the road surface at predetermined intervals by the light beams L1 reflected by the beam splitters 5 to 9 and the reflection mirror 11. When the vehicle moves forward, it irradiates the front road surface from the two light beam irradiating devices 2 and 2 disposed on both sides of the windshield of the vehicle 1, and when traveling backward, the two lights disposed on both sides of the rear glass. Irradiate the rear road surface from the beam irradiation devices 2 and 2.
When the vehicle 1 turns, as shown in FIG. 1, two curved light spot patterns Lb and Lb are formed around the front of the traveling direction or in front of the vehicle 1 at the maximum turning width interval. Here, when the vehicle 1 moves forward, it irradiates the front road surface from the two light beam irradiation devices 2 and 2 disposed on both sides of the windshield, and when it moves backward, the two beams disposed on both sides of the rear glass. Irradiate the road surface behind the light beam irradiation devices 2 and 2.

Here, with respect to each of the beam splitters 5 to 9 and the reflection mirror 11 in the light beam irradiation apparatus 2 according to the present embodiment, the reflectance Rn and the transmittance Tn and the light emitted from each of the beam splitters 5 to 9 and the reflection mirror 11 (light An example of the intensity of the beam L1) is set as Example 1 as shown in Table 1 below. In this case, N = 6, where N is the total of the plurality of beam splitters including the reflection mirror 11. The reflection mirror 11 is a beam splitter having a reflectance of 100% and a transmittance of 0%.
Table 1 is represented as a graph in FIG.
The emitted light intensity indicates the intensity of each reflected light L1 when the intensity of the light beam L incident on or transmitted through each beam splitter is 1.
The settings in Table 1 below are calculated as the following equations (4) and (5).
R1 = 1 / N, (4)
Rn = Rn ₋₁ / Tn ₋₁ (5)
However, n is 1, 2, ... N.
According to the first embodiment, the intensity of all the reflected light beams L1 is 0.167, which is substantially equal. An ideal state with no light absorption is as shown in Table 1. However, in reality, there is a case where slight correction is necessary due to light absorption.

  As described above, the light beam irradiation device 2 according to the present embodiment can generate the light beam L1 branched from one light source 4 into six. In addition, the light beam L1 can be independently controlled to form a light spot having the same intensity of the light beam L1 in a desired shape at an arbitrary position. Therefore, it is possible to display various information with high visibility by irradiation, and it is suitable for mounting on the vehicle 1 because the apparatus is small. Further, the light spot patterns La and Lb formed on the road surface by the light beam irradiation device 2 are not continuous linear shapes, but form a dotted line pattern with intermittent light spots, so that the visibility is high.

In the above embodiment, when it is necessary to control the shape and size of the light spot formed by each light beam L1, the beam divergence angle of the light beam L emitted by the beam expander 20 is appropriately set. It may be controlled to.
Further, an optical element having lens power may be disposed immediately after the beam expander 20. Alternatively, an optical element having lens power is disposed between the beam expander 20 and the galvanometer mirrors 13 to 18 so as to act on each light beam, thereby controlling the light beam L1 to converged light or divergent light. You may make it do. The same effect can be obtained by these.

Next, other embodiments of the present invention will be described. The same or similar members and parts as those of the above-described embodiments are denoted by the same reference numerals, and the description thereof will be omitted.
FIG. 6 is a front view showing an optical system of the light beam irradiation apparatus 22 according to the second embodiment of the present invention. In the figure, in the optical path of the reflected light of the light beam L emitted from the light source 4, between the beam expander 20 and each galvanometer mirror 13-17, it replaces with the beam splitters 5-9 and is plate-shaped 1st thru | or 1st. Four half mirrors 23, 24, 25, and 26 are arranged as light beam splitting means. In the present embodiment, four half mirrors 23, 24, 25, 26 are arranged, and a reflection mirror 11 for reflecting the light beam L 2 is provided in front of the light beam L 2 that passes through the fourth half mirror 26. Yes. Therefore, five galvanometer mirrors 13 to 17 are also arranged.
The galvanometer mirrors 13 to 17 are connected to the control circuit 19 as in the first embodiment and can adjust the deflection angle. However, the description of the control circuit 19 is omitted in the following embodiments.
Further, in the drawing, the galvanometer mirrors 13 to 17 are gradually separated from the half mirrors 23 to 26 and the reflection mirror 11 which are opposed to the half mirrors 23 to 26 and the reflection mirror 11 arranged along the light beam L, respectively. They are sequentially arranged so as to incline so as to increase.

The light beams L1 reflected by the half mirrors 23 to 26 and the reflecting mirror 11 are reflected substantially at right angles to the galvano mirrors 13 to 17, respectively, and the light beams L1 reflected by the galvano mirrors 13 to 17 are incident. It is set to reflect at a substantially right angle to the side.
According to the optical system of the light beam irradiation apparatus 22 according to the present embodiment, each optical element is arranged in the same plane, and each light beam L1, L2 is not likely to interfere with each optical element such as a half mirror. It is comprised so that it may drive | work in the same plane.

  Since the light beam irradiation apparatus 22 according to the present embodiment employs the half mirrors 23 to 26 instead of the cubic type beam splitters 5 to 9 in addition to the effects of the first embodiment described above, the manufacturing cost is reduced. There are advantages in that it is inexpensive and light in weight. In addition, since the optical system is within the same plane, the thickness of the apparatus is further reduced and the apparatus can be further reduced in size.

Next, a third embodiment of the present invention will be described with reference to a front view of the optical system of the light beam irradiation apparatus shown in FIG.
In the light beam irradiation device 28 shown in FIG. 7, in the optical path of the light beam L emitted from the light source 4, first to fifth light beam splitting means are provided between the beam expander 20 and the galvanometer mirrors 13 to 18. Beam splitters 29 to 33 are arranged. These include a first beam splitter 29, a second beam splitter 30, a third beam splitter 31, a fourth beam splitter 32, and a fifth beam splitter 33. A half-mirror coating of a dielectric multilayer film or a metal film is applied as a semi-transmissive film 34a (divided surface) to the slope on the side where the light beam L and the transmitted light L2 emitted from the light source 4 of each beam splitter 29 to 33 are incident. Yes.
In addition, the first to fifth beam splitters 29 to 33 constitute a light splitting element 35 in which the inclined surface provided with the semi-transmissive film 34a and the inclined surface opposite to the inclined surface are sequentially joined together in a substantially linear shape. is doing. The slope facing the slope having the semi-transmissive film 34a of the rearmost fifth beam splitter 33 is a reflecting surface 34b having a transmittance of 0%.

Therefore, the light beam L that has passed through the beam expander 20 enters the light splitting element 35, and is branched into the reflected light L1 and the transmitted light L2 by the semi-transmissive film 34a provided on the incident-side slope of the first beam splitter 29. . The reflected light beam L1 is directed to the first galvanometer mirror 13, and the transmitted light beam L2 is branched into reflected light L1 and transmitted light L2 by a semi-transmissive film 34a between the first and second beam splitters 29 and 30. Similarly, the transmitted light beam L2 is sequentially branched into the reflected light L1 and the transmitted light L2 by the semi-transmissive film 34a provided on the inclined surface on the incident side of the third to fifth beam splitters 31, 32, 33. Then, the light beam L2 transmitted through the semi-transmissive film 34a on the incident-side inclined surface of the fifth beam splitter 33 is totally reflected by the reflecting surface 34b provided on the emitting-side inclined surface to become reflected light L1.
Then, the light beams L1 reflected by the beam splitters 29 to 33 are reflected by the galvanometer mirrors 13 to 18, respectively, are emitted to the outside of the device 28, and are irradiated onto the road surface as light spots.
In the example shown in FIG. 7, the incident-side semi-transmissive film 34a and the reflective surface 34b of each of the beam splitters 29 to 33 are set at an inclination angle of 45 ° with respect to the light beam L and the transmitted light L2, and each reflected light L1 is reflected substantially at right angles to the incident side light beam L and transmitted light L2.

  Since the light beam irradiation device 28 according to the present embodiment employs an integrated light splitting element 35 instead of the individually arranged beam splitters 5 to 9 in addition to the effects of the first embodiment described above, There are few means for fixing, and adjustment is easy.

In each of the above-described embodiments, the light beam L emitted from one light source 4 is split into a plurality of light beams by the light beam splitting means and reflected in one direction (for example, in the same plane) via a galvanometer mirror. 1 light spot pattern La or Lb is formed, but since at least two light spot patterns La or Lb are required to display the vehicle width of the vehicle 1, each of the two light beams The irradiation devices 2, 22, and 28 need to be arranged on the front side and the rear side.
On the other hand, in the embodiment described below, two light spot patterns La and La or Lb and Lb are formed from a light beam L emitted from one light source.

Next, a light beam irradiation apparatus according to a fourth embodiment will be described with reference to FIGS. FIG. 8 is a diagram showing a light spot pattern formed by a light beam from a light beam irradiation device of a vehicle, FIG. 9 is a front view of an optical system of the light beam irradiation device, and FIG. 10 is a graph showing characteristics of the light beam.
The vehicle 1 shown in FIG. 8 is provided with a light beam irradiation device 38 at the center inside the windshield. Although not shown, a light beam irradiation device 38 is also provided at the center of the rear rear glass.
The optical system of the light beam irradiation device 38 is shown in FIG. That is, the light beam irradiation device 38 includes the light source 4 and the beam expander 20 that performs shaping such as expanding the outer diameter of the light beam L emitted from the light source 4. An integrated light splitting element 39 for sequentially branching the light beam L into reflected light L1 and transmitted light L2 is disposed in front of the beam expander 20 in the traveling direction of the light beam L.

The light splitting element 39 is formed in a substantially linear shape by joining a plurality of substantially right-angled isosceles triangular columnar prisms having two inclined surfaces and a bottom surface when viewed from the front so that the vertical angles are arranged in a direction opposite to each other alternately. Is arranged. In the example shown in the figure, nine prisms are joined, and these are joined in order from the light source 4 side, the first beam splitter 42, the second beam splitter 43, the third beam splitter 44, the fourth beam splitter 45, and the fifth beam splitter. 46, sixth beam splitter 47, seventh beam splitter 48, eighth beam splitter 49, and ninth beam splitter 50 (light beam splitting means).
Then, one of the inclined surfaces of the adjacent triangular prism-shaped beam splitters 42 to 50, which is the inclined surface on the light source 4 side, is coated with a half mirror coating with a dielectric multilayer film or a metal film, and the semi-transmissive film 40 (dividing surface) ) Respectively. In the ninth beam splitter 50, the inclined surface facing the semi-transmissive film 40 constitutes a reflection surface 41 (divided surface) for total reflection.

Therefore, the light beam L incident on the first beam splitter 42 is divided into reflected light L1 and transmitted light L2 by the semi-transmissive film 40, and the reflected light L1 is, for example, incident light L on one side (left side in the figure). Reflected at a substantially right angle. The transmitted light L2 is divided into reflected light L1 and transmitted light L2 by the semi-transmissive film 40 of the second beam splitter 43, and the reflected light L1 is converted into, for example, transmitted light L2 on the other side (right side in the figure) opposite to one side. On the other hand, it is reflected at a substantially right angle.
In this way, in the first to ninth beam splitters 42 to 50, when the light beam L and the transmitted light L2 are divided into the reflected light L1 and the transmitted light L2 by the semi-transmissive film 40, the reflected light L1 is alternately switched to one side. Divided on the other side. Furthermore, the light beam L1 is reflected on the reflection surface 41 of the ninth beam splitter 50 on the side opposite to the light beam L1 reflected by the facing semi-transmissive film 40.
Therefore, in the example shown in the figure, the reflected light L1 from the odd-numbered semi-transmissive film 40 is reflected to one side, and the reflected light L1 from the even-numbered semi-transmissive film 40 and the reflecting surface 41 is reflected to the other side.

Galvano mirrors corresponding to the number of reflected light beams L1 are arranged on both sides of the light splitting element 39, respectively. 9, on one side (left side) of the light splitting element 39, the first, third, fifth, seventh, and ninth beam splitters 42, 44, 46, 48, and 50 are opposed to the semi-transmissive films 40, respectively. The first, third, fifth, seventh, and ninth galvanometer mirrors 52, 54, 56, 58, and 60 are provided. The light beams L1 reflected by the semi-transmissive films 40 of the first, third, fifth, seventh, and ninth beam splitters 42, 44, 46, 48, and 50 are reflected, for example, at right angles, respectively. Will be injected to the outside.
Similarly, the other side (right side) of the light splitting element 39 is opposed to the semi-transmissive films 40 and the reflecting surfaces 41 of the second, fourth, sixth, and eighth beam splitters 43, 45, 47, and 49. Second, fourth, sixth, eighth, and tenth galvanometer mirrors 53, 55, 57, 59, 61 are provided. The light beams L1 reflected by the semi-transmissive films 40 and the reflecting surfaces 41 of the second, fourth, sixth, and eighth beam splitters 43, 45, 47, and 49 are reflected, for example, at right angles, respectively, in the A direction. It will be injected outside.
Moreover, each galvanometer mirror 52, 54, 56, 58, 60 on one side is attached to the installation plate 64. The other galvanometer mirrors 53, 55, 57, 59 and 61 are attached to the installation plate 65.

Since the light beam irradiation device 38 according to the present embodiment has the above-described configuration, in FIG. 9, the light beam L emitted from the light source 4 by the laser has a desired diameter increased by the beam expander 20. It is processed. The shaped light beam L is incident on the semi-transmissive film 40 of the first beam splitter 42 of the light splitting element 39.
In the first beam splitter 42, the light is branched into reflected light L <b> 1 and transmitted light L <b> 2 at a preset ratio by the semi-transmissive film 40. The reflected light L1 enters the first galvanometer mirror 52 on one side. The light beam L2 transmitted through the first beam splitter 42 is branched into the reflected light L1 and the transmitted light L2 at a preset ratio by the semi-transmissive film 40 of the second galvanometer mirror 43, and the reflected light L1 is the second galvanometer on the other side. Incident on the mirror 53.
In this way, the transmitted light L2 sequentially repeats the same action in the third to ninth beam splitters 44 to 50, and the respective reflected light L1 is alternately reflected on one side and the other side. The light beam L2 that passes through the ninth beam splitter 50 is totally reflected by the reflecting surface 41 and travels toward the other tenth galvanometer mirror 61.

  The galvanometer mirrors 52, 54, 56, 58, and 60 on one side reflect each reflected light L1 at, for example, a substantially right angle and emit it in the A direction to form a light spot pattern on the road surface. At the same time, the galvanometer mirrors 53, 55, 57, 59, 61 on the other side reflect each reflected light L1 at, for example, a substantially right angle and emit it in the A direction to form a light spot pattern on the road surface. Therefore, the light beams L1 and L1 reflected by the galvanomirror groups on both sides are irradiated in a substantially parallel manner, and a pair of light spot patterns La and La or Lb and Lb are formed on both sides of the vehicle 1, respectively. it can.

Here, regarding the semi-transmissive film 40 and the reflective surface 41 of each of the beam splitters 42 to 50 in the light beam irradiation apparatus 38 according to the present embodiment, the reflectance Rn and the transmissivity Tn, and the semi-transmissive film 40 and the reflective surface 41 are reflected. An example of the intensity of the emitted light (reflected light L1) is set as Example 2 as shown in Table 2 below. In this case, if the total of the semi-transmissive film 40 and the reflecting surface 41 of each beam splitter 42 to 50 is N, N = 10. Table 2 is represented as a graph in FIG.
The emitted light intensity indicates the intensity of the reflected light L1 when the intensity of the light beam L or the transmitted light L2 incident on each beam splitter is 1.
The settings in Table 2 below are calculated according to the above formulas (4) and (5). Here, n is 1, 2,... N.
According to the second embodiment, in the ideal state where there is no light absorption or the like, the intensity of all the reflected light beams L1 is approximately equal to 0.1. Actually, some correction may be necessary due to light absorption and the like.

As described above, the light beam irradiation device 38 according to the present embodiment divides the reflected light L1 into a plurality of reflected lights L1 based on one light beam L, and irradiates the reflected light L1 in two directions. Can do. Therefore, since the two light spot patterns La, La or Lb, Lb formed on the front or rear of the vehicle 1 can be obtained by one light beam irradiation device 38, the structure is further increased than the above-described devices 2, 22, 28, etc. It can be done easily and the cost can be reduced.
Further, the light source 4, the beam expander 20, and the light splitting element 39 are made into one unit, and each of the five galvanometer mirrors on both sides is unitized by the installation plates 64 and 65, so that the configuration of the entire apparatus is made up of three units. It is possible to control separately, and the whole apparatus can be simplified and maintenance can be facilitated.
Further, since the plurality of reflected lights L1 and L1 on both sides of the light splitting element 39 are set in parallel, the interval between the units of the galvanometer mirrors installed on both sides may be arbitrarily set. When it is desired to separate the two light spot patterns La, La or Lb, Lb on the road surface, the deflection angles of the galvanometer mirrors 52, 54, 56, 58, 60 on both sides and 53, 55, 57, 59, 61 are provided. Without changing the distance, the unit can be moved in parallel to increase the interval between them.
In the light splitting element 39, the reflected light L1 is alternately reflected in two directions. However, the present invention is not limited to this, and the reflected light L is selectively reflected in any direction in any order. Can do.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
The light beam irradiation device 68 shown in FIG. 11 is different from the fourth embodiment in the configuration of the light splitting element 69 and the arrangement of the galvanometer mirrors on both sides thereof. In the light splitting element 69, the prism closest to the light source 4 has a trapezoidal column shape, which is referred to as a first beam splitter 70. The other prisms that follow the first beam splitter 70 are substantially isosceles prismatic prisms that are substantially isosceles triangular prisms so that the vertical angles are arranged in opposite directions in the same manner as in the fourth embodiment. They are arranged in a straight line.
In the example shown in the drawing, seven substantially isosceles triangular prisms are sequentially surface joined to the trapezoidal slope of the first beam splitter 70, and these are joined in order from the light source 4 side to the second beam splitter 71, the third beam splitter 71, and the third beam splitter 71. A beam splitter 72, a fourth beam splitter 73, a fifth beam splitter 74, a sixth beam splitter 75, a seventh beam splitter 76, and an eighth beam splitter 77 are provided. These constitute light beam splitting means. Moreover, the incident surface 70 a of the first beam splitter 70 is a surface orthogonal to the light beam L.
Further, the light splitting element 69 is formed so that the incident light beam L and the transmitted light L2 are collinear, and both side surfaces 69a and 69b are formed in a substantially trapezoidal column shape parallel to the light beam L and the transmitted light L2.

A half mirror coating is applied to one of the slopes of the adjacent beam splitters 70 to 77 which are surface-bonded, here, the slope on the light source 4 side with a dielectric multilayer film or a metal film. ). In the eighth beam splitter 77, the slope facing the semi-transmissive film 78 on which the transmitted light L <b> 2 is incident constitutes a reflective surface 79.
Therefore, the light beam L or the transmitted light L2 incident from the incident surface 70a of the first beam splitter 70 is reflected by the reflected light L1 and the transmitted light at a ratio preset by the semi-transmissive films 78 of the second to eighth beam splitters 71 to 77. Divided into L2. Moreover, the reflected light L1 reflected by the odd-numbered semi-transmissive film 78 is reflected on one side (left side), and the reflected light L1 reflected by the even-numbered semi-transmissive film 78 is reflected on the other side (right side).
Further, the apex angles θ of the second to eighth beam splitters 71 to 77 having a substantially isosceles triangular column shape are such that the reflected light L1 from the semi-transmissive film 78 provided on each inclined surface is relative to the light beam L or the transmitted light L2. Are formed to have the same acute angle θa. Therefore, the apex angle θ is preferably less than 45 °.

On one side of the light splitting element 69, a first galvano mirror 80, a third galvano mirror 82, a fifth galvano mirror 84 for reflecting four reflected lights L 1 reflected by the odd-numbered semi-transmissive film 78, Seven galvanometer mirrors 86 are provided. On the other side of the light splitting element 69, a second galvanometer mirror 81, a fourth galvanometer mirror 83, a sixth galvanometer mirror 85, a fourth galvanometer mirror 85 for reflecting the four reflected lights L 1 reflected by the even-numbered semi-transmissive film 78, Eight galvanometer mirrors 87 are provided. Each of the galvanometer mirrors 80 to 87 can rotate about two axes and can be driven to tilt at an arbitrary angle. The four galvanometer mirrors 80, 82, 84, 86 on both sides are attached to the installation plates 64, 65.
The galvanometer mirrors 80, 82, 84, 86 provided on one installation plate 64 and the galvanometer mirrors 81, 83, 85, 87 provided on the other installation plate 65 are substantially V-shaped across the light splitting element 6. It is arranged so as to be inclined. The galvanometer mirrors 80 to 87 are arranged so as to reflect the incident reflected light L1 and emit the light beam L1 in a direction in which it is diffused outward with respect to the light splitting element 69.

Since the light beam irradiation device 68 according to the present embodiment has the above-described configuration, the light beam L emitted from the light source 4 is shaped by the beam expander 20 in FIG. The light is incident from the incident surface 70a of the beam splitter 70 and is divided into the reflected light L1 and the transmitted light L2 by the semi-transmissive film 78 of the second beam splitter 71 at a preset ratio. The reflected light L1 is reflected at an acute angle θa with respect to the light beam L and travels toward the first galvanometer mirror 80 on one side.
On the other hand, the transmitted light L2 is split by the third beam splitter 72 into the reflected light L1 and the transmitted light L2 at a preset ratio by the semi-transmissive film 78. The reflected light L1 is reflected at an acute angle θa and is incident on the second galvanometer mirror 81 on the other side. Then, the transmitted light L2 is sequentially branched into the reflected light L1 and the transmitted light L2 by the semi-transmissive films 78 of the fourth to eighth beam splitters 73 to 77 by the same action. Then, the transmitted light L 2 entering the eighth beam splitter 77 is reflected by the reflecting surface 79 and enters the other eighth galvanometer mirror 87.
Therefore, the four reflected lights L1 reflected by the odd-numbered semi-transmissive film 78 are substantially parallel to each other, reflected to one side at an acute angle, and the first, third, fifth, and seventh beam splitters 80 and 82 are reflected. , 84, 86 are further reflected and emitted outward substantially in parallel. Then, one light spot pattern La (or Lb) is formed on the road surface. In addition, the four reflected lights L1 reflected by the even-numbered semi-transmissive film 78 are also substantially parallel to each other and reflected to the other side at an acute angle, so that the second, fourth, sixth, eighth beam splitters 81, 83, The light is further reflected at 85 and 87, and is emitted substantially in parallel to the outside. Then, the other light spot pattern La (or Lb) is formed on the road surface.

  As described above, according to the present embodiment, in addition to the effects of the fourth embodiment, each of the four reflected lights L1 on both sides of the light splitting element 69 is incident on the light beam L or the transmitted light L2. Since it is configured to reflect at an acute angle θa with respect to the optical axis, each of the four galvanometer mirrors on both sides can be disposed closer to the light splitting element 69 and closer to the light source 4 than the light splitting element 69. The size can be further reduced.

Next, a sixth embodiment of the present invention will be described with reference to FIG.
The light beam irradiation apparatus 90 according to the sixth embodiment has a configuration roughly similar to the light beam irradiation apparatus 68 according to the fifth embodiment, and is different between the light splitting element 91 and the galvanometer mirrors on both sides. To do.
In the light beam irradiation apparatus 90 shown in FIG. 12, the light splitting element 91 is configured by surface-joining a plurality of triangular prisms having different apex angles.
In the drawing, the first beam splitter 92 of the light splitting element 91 has a substantially right triangle shape, and has an incident surface 92 a orthogonal to the light beam L passing through the beam expander 20. Following the bottom surface of the first beam splitter 92, five substantially triangular prismatic triangular prisms are sequentially surface-joined with their apex angles α1, α2, α3, α4, and α5 facing each other. These substantially triangular prismatic triangular prisms are referred to as a second beam splitter 93, a third beam splitter 94, a fourth beam splitter 95, a fifth beam splitter 96, and a sixth beam splitter 97 in order from the light source 4 side. These constitute light beam splitting means.
In addition, as shown in FIG. 12, the second to sixth beam splitters 93 to 97 are adjacent to both sides of the two oblique sides sandwiching the apex angles α1, α2, α3, α4, and α5 of each triangle that is a columnar end surface. And the length of the hypotenuse of the other triangle. Since the apex angles α1 to α5 are different from each other, the two hypotenuses of each triangle have different lengths. Moreover, the light splitting element 91 is assumed that the optical axes of the incident light beam L and the transmitted light L2 are collinear, and both side surfaces 91a and 91b thereof are parallel to the light beam L and the transmitted light L2, and are substantially trapezoidal as a whole. It is formed in a columnar shape.

Then, a half mirror coating is formed by a dielectric multilayer film or a metal film on one of the bottom surfaces or the inclined surfaces where the adjacent beam splitters 92 to 97 are bonded to each other, here the inclined surfaces on the light source 4 side of the second to sixth beam splitters 93 to 97. These are used as semi-permeable membranes 98 (divided surfaces). Further, in the sixth beam splitter 97, the slope facing the semi-transmissive film 98 on which the transmitted light L2 is incident constitutes a reflective surface 99.
Therefore, the light beam L or the transmitted light L2 incident from the incident surface 92a of the first beam splitter 92 is reflected by the reflected light L1 and the transmitted light at a ratio set in advance by the semi-transmissive films 98 of the second to sixth beam splitters 93 to 97. Divided into L2. Moreover, the reflected light L1 reflected by the odd-numbered semi-transmissive film 98 is reflected on one side (left side), and the reflected light L1 reflected by the even-numbered semi-transmissive film 98 and the reflective surface 99 is reflected on the other side (right side). It will be.
The apex angles α1, α2, α3, α4, and α5 of the second to sixth beam splitters 93 to 97 are set so that the maximum is close to the light source 4 and gradually decreases as the distance from the light source 4 increases. . Therefore, the angles β1, β2, β3, β4, β5, and β6 of the reflected light L1 at each semi-transmissive film 98 with respect to the incident light beam L and transmitted light L2 are formed so as to gradually decrease as the distance from the light source 4 increases. Yes. Therefore, the plurality of reflected lights L1 and L1 on both sides are reflected in the gathering direction.

On one side of the light splitting element 91, there are a first galvanometer mirror 101, a third galvanometer mirror 103, and a fifth galvanometer mirror 105 for reflecting the three reflected lights L1 reflected by the odd-numbered semi-transmissive film 98, respectively. Is provided. On the other side of the light splitting element 98, the second galvanometer mirror 102, the fourth galvanometer mirror 104, and the sixth galvanometer for reflecting the three reflected lights L 1 reflected by the even-numbered semi-transmissive film 98 and the reflecting surface 99. Each of the mirrors 106 is provided. Each of the galvanometer mirrors 101 to 106 can be rotated in an arbitrary direction, and is composed of a very small movable mirror such as a MEMS mirror.
The three galvanometer mirrors 101, 103, and 105 on one side are attached to a small installation plate 108 and are arranged at a minute interval. Similarly, the other three galvanometer mirrors 102, 104, and 106 are attached to a small installation plate 109, and are arranged at a minute interval. As a result, the three reflected lights L1 and L1 reflected by the galvanometer mirrors 101, 103, 105 and 102, 104, 106 can be emitted in directions parallel to each other.
In this embodiment, by changing the reflection angles β1 to β6 of the plurality of reflected lights L1 and L1 reflected in both directions by the light splitting element 91, the galvanometer mirrors 101, 103, 105 on one side and the other side are changed. Since they can be assembled in the vicinity of the galvanometer mirrors 102, 104, and 106, small galvanometer mirrors 101 to 106 can be employed. In particular, since the reflection angles β1 and β2 of the reflected light L1 on the side close to the light source 4 are set to be relatively large and the reflection angles β3 to β6 of the reflected light L1 are sequentially set to decrease as the distance from the light source 4 increases, Each of the three reflected lights L1 can be assembled. Therefore, the installation plates 108 and 109 of the galvanometer mirrors 101, 103, 105 and 102, 104, 106 can be provided substantially symmetrically at a position close to the light source 4.

Since the light beam irradiation apparatus 90 according to the present embodiment has the above-described configuration, the light beam L incident on the light splitting element 91 from the light source 4 via the beam expander 20 is semi-transmitted by the second beam splitter 93. The film 98 is divided into reflected light L1 and transmitted light L2 at a predetermined ratio. Further, the transmitted light L2 is sequentially divided into reflected light L1 and transmitted light L2 by the semi-transmissive films 98 between the beam splitters 93 to 97 in the same manner, and each reflected light L1 is alternately reflected on one side and the other side. Is done. The transmitted light L2 is totally reflected at the reflecting surface 99.
In addition, the reflected light L1 on both sides is deflected in the direction of condensing, and is deflected by the small galvanometer mirrors 101, 103, 105 and the galvanometer mirrors 102, 104, 106, respectively, and reflected light L1, parallel to each other. L1 is emitted to the outside and forms a light spot pattern on the road surface.

  According to the present embodiment, in addition to the above-described effects, by appropriately selecting the apex angles α1 to α5 of the beam splitters 93 to 97 of the light splitting element 91, the exit angle of the reflected light L1 to be emitted can be freely set. Can be set. In particular, since the reflection angles β1 and β2 of the reflected light L1 on the side close to the light source 4 are set relatively large and the reflection angles β3 to β6 of the reflected light L1 are sequentially set smaller as the distance from the light source 4 increases, the side closer to the light source 4 The galvanometer mirrors 101 to 106 can be arranged on the apparatus 90, which is advantageous for downsizing and multi-functioning of the apparatus 90.

In each of the above-described embodiments, the number of beam splitters and the number of galvanometer mirrors can be set freely.
In the light beam irradiation device 68 according to the fifth embodiment, the configuration in which the reflected light from the light splitting element 69 is reflected at an acute reflection angle with respect to the optical axis of the incident light beam L or transmitted light L2, You may employ | adopt for the light beam irradiation apparatus which has arrange | positioned the several galvanometer mirrors 13-18 in one direction in 1st thru | or 3rd embodiment.
Similarly, the configuration in which reflected light from the light splitting element 98 of the light beam irradiation apparatus 90 according to the sixth embodiment is condensed and deflected by small galvanometer mirrors 101 to 106 such as MEMS mirrors is the first to third. You may employ | adopt for the light beam irradiation apparatus which arrange | positioned the several galvanometer mirrors 13 thru | or 18 in one direction in the embodiment.
Further, the reflection mirrors 23 to 26 in the light beam irradiation apparatus 22 according to the second embodiment may be employed in place of the light splitting elements 39, 69, 91 in the fourth to sixth embodiments. In this case, the reflection mirrors 23 to 26 may appropriately adjust the inclination angle of the light beam L or the transmitted light L2 with respect to the optical axis.
A deflecting beam splitter may be adopted as the light beam splitting means. Thus, the incident light beam or transmitted light can be divided into P wave and S wave, and one can be reflected light and the other can be transmitted light.

In each of the above-described embodiments, when the light beam irradiation device is mounted on the vehicle driving support device, when the light beam is reflected in one direction by a plurality of light beam dividing means, both sides in the windshield and the rear glass are used. However, the present invention is not limited to such a configuration, and can be attached at an arbitrary position. For example, you may employ | adopt outside vehicles, such as the front bumper vicinity and rear bumper, and a vehicle roof. If the light beam irradiation device is installed at such a position, it is possible to prevent the adverse effect that the light beam receives when passing through the windshield and rear glass.
Moreover, the light beam irradiation apparatus 2, 22, 28, 38, 68, 90 by this invention is not limited to a vehicle driving assistance apparatus, It can be used for arbitrary uses, such as for displays and for stage lighting.

It is the perspective view which used the light beam irradiation apparatus by 1st embodiment of this invention for the vehicle driving assistance apparatus. It is a front view of the optical system which shows the light beam irradiation apparatus by 1st embodiment. FIG. 3 is a plan view of FIG. 2. (A), (b), (c), (d) is a figure which shows the example of a beam expander. It is a graph which shows the reflectance in a beam splitter, the transmittance | permeability, and emitted light intensity. It is a front view of the optical system which shows the light beam irradiation apparatus by 2nd embodiment. It is a front view of the optical system which shows the light beam irradiation apparatus by 3rd embodiment. It is the perspective view which used the light beam irradiation apparatus by 4th embodiment for the vehicle driving assistance apparatus. . It is a front view of the optical system which shows the light beam irradiation apparatus by 4th embodiment. It is a graph which shows the reflectance in a beam splitter, the transmittance | permeability, and emitted light intensity. It is a front view of the optical system which shows the light beam irradiation apparatus by 5th embodiment. It is a front view of the optical system which shows the light beam irradiation apparatus by 6th Embodiment.

Explanation of symbols

2, 22, 28, 38, 68, 90 Light beam irradiation device 4 Light source 5, 6, 7, 8, 9, 29, 30, 31, 32, 33, 42, 43, 44, 45, 46, 47, 48 49, 50, 70, 71, 72, 73, 74, 75, 76, 77, 92, 93, 94, 95, 96, 97 Beam splitter (light beam splitting means)
10b, 34a, 40, 78, 98 Semi-permeable membrane (divided surface)
11 reflection mirror (light beam splitting means)
13, 14, 15, 16, 17, 18, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 80, 81, 82, 83, 84, 85, 86, 87, 101, 102, 103, 104, 105 Galvano mirror (deflector)
20 Beam expander (beam shaping means)
23, 24, 25, 26 Half mirror (light beam splitting means)
34b, 41, 79, 99 Reflecting surface (light beam splitting means)
35, 39, 69, 91 Light splitting element L1, reflected light (light beam)
L2 Transmitted light (light beam)

Claims (18)

  A light source that emits a light beam, a plurality of light beam splitting means that branches the incident light beam into reflected light and transmitted light and arranged in the traveling direction of the transmitted light, and a light beam reflected by the light beam splitting means A light beam irradiation apparatus comprising: a deflector having a variable deflection direction for deflecting each of the light beams.   The light beam irradiation apparatus according to claim 1, wherein the deflector is disposed in one direction with respect to the plurality of light beam splitting units.   The deflector is disposed in a plurality of directions with respect to the plurality of light beam splitting means, and the light beam splitting means selectively reflects reflected light to the deflector disposed in a plurality of directions, The light beam irradiation apparatus according to claim 1, wherein the light beams respectively deflected by the deflectors arranged in the plurality of directions are emitted in different directions.   4. The light beam irradiation apparatus according to claim 3, wherein the light beams reflected by the plurality of light beam splitting means are alternately reflected in two directions.   5. The structure according to claim 1, wherein at least one of the light beams reflected by the plurality of light beam splitting units is reflected at an acute angle with respect to the optical axis of the light beam incident on the light beam splitting unit. The light beam irradiation apparatus described in 1.   The light beam irradiation apparatus according to claim 1, wherein the light beam splitting unit is configured such that a plurality of light beams reflected in the same direction are gathered toward the deflector.   The light beam irradiation apparatus according to claim 1, wherein the plurality of light beam splitting units have different reflectances.   The light beam irradiation apparatus according to claim 7, wherein the plurality of light beam splitting units are set so that the reflectance gradually increases in a traveling direction of transmitted light. N light beams are arranged in the traveling direction of the transmitted light beam, and the reflectance in the n-th (n = 1, 2,..., N) light beam dividing device is Rn and the transmittance is Tn. The light beam irradiation apparatus according to claim 1, wherein the following expressions (1) to (3) are satisfied.
0.5 / N ≦ R1 <1.5 / N (1)
Tn = 1−Rn (2)
0.7 × Rn ₋₁ / Tn ₋₁ <Rn <1.3 × Rn ₋₁ / Tn ₋₁ (3)   The light beam irradiation apparatus according to claim 1, wherein the plurality of light beam splitting units are formed by bonding a plurality of triangular prisms, and a split surface is provided on the bonding surface.   The light beam irradiation apparatus according to claim 10, wherein the plurality of triangular prisms are alternately displaced and have different apex angles.   The light beam irradiation apparatus according to claim 10 or 11, wherein a length of the bonding surface is different in a longitudinal sectional view of the light beam splitting unit.   10. The light beam irradiation apparatus according to claim 1, wherein the light beam splitting unit is formed by bonding parallelogram prisms, and a split surface is provided on the bonding surface.   The light beam irradiation apparatus according to claim 1, wherein the light beam splitting unit is a plate-shaped half mirror.   15. The light beam irradiation apparatus according to claim 1, wherein the polarizer is connected to control means for controlling the deflected light beam to a desired deflection angle.   The light beam irradiation apparatus according to claim 1, wherein a light beam shaping unit that adjusts a light beam diameter of the light beam is disposed between the light source and the light beam splitting unit.   The light beam irradiation apparatus according to claim 16, wherein the light beam shaping means is a beam expander. The light beam irradiation apparatus according to claim 16 or 17, wherein the light beam transmitted through the light beam shaping means is convergent light or divergent light.

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