JP5880951B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a vehicular headlamp, and more particularly to a vehicular headlamp capable of speeding up awareness in peripheral vision in a dark environment during night driving.

  Conventionally, in the field of vehicle headlamps, it has been required to improve the brightness so that it can be driven at night as well as in the daytime. To meet this demand, high luminous flux light sources such as halogen lamps and HID lamps are used. Various headlamps have been proposed to improve brightness (luminance, luminous flux, luminous efficiency, etc.) such as by improving the optical system (see, for example, Patent Document 1).

  In consideration of the characteristics of the human eye, which is more sensitive to blue light than red light in a dark environment during night driving, as shown in FIGS. 29 (a) and 29 (b), during night driving, From the viewpoint of improving visibility, the front area A1 is irradiated with light having a greater amount of blue component light than the red component light, and light having a greater amount of red component light is centered in the area A1 from the viewpoint of enhancing the color and shape recognition. A headlamp has also been proposed that irradiates a nearby area A2 (and an area A3 above a horizontal plane by a predetermined angle) (see, for example, Patent Document 2).

JP 2007-59162 A JP 2008-204727 A

  However, heretofore, it has not been known at all how blue light affects the perception of peripheral vision in a dark environment during night driving.

  30A is an explanatory diagram of the driver's central vision and peripheral vision, FIG. 30B is a diagram for explaining the relationship between the driver's central vision, peripheral vision, cones, rods, etc., FIG. FIG. 6 is a flowchart for explaining a flow until the driver recognizes an object (such as a pedestrian or an obstacle) existing in the peripheral vision.

  A driver who is gazing at a distant place (for example, see the three circles in FIG. 30A and the arrow in FIG. 30B) recognizes objects (pedestrians, obstacles, etc.) existing in the peripheral vision. When the flow up to this is examined in detail, as shown in FIG. 31, the driver first notices the object with peripheral vision (housing) (step S1: Yes), and then turns his eyes in that direction (step S1). S2) After that, the object (color, shape, etc.) is recognized by the central view (cone) (step S3). When it is not noticed by peripheral vision (case) (step S1: No), it is overlooked (step S4). That is, in order to recognize an object existing in the peripheral visual field, it is important to notice first, and unless it is noticed, the target object existing in the peripheral visual field cannot be recognized.

  Especially in dark environments when driving at night, there are many situations that require awareness of peripheral vision (= body = dark vision sensitivity) (for example, turning left and right at an intersection, branching, changing lanes, lane keeping) It is important to speed up awareness in peripheral vision. For example, in front of the vehicle as viewed from the driver, the light from the vehicle headlamp is not sufficiently irradiated, so that the object present in the peripheral visual field is not noticeable. In addition, the wider the road width, the worse the awareness in front of the vehicle.

  Cones and rods are distributed on the retina of the human eye. FIG. 32 is a table that summarizes the characteristics of peripheral vision and central vision. As shown in FIG. 32, cones and rods are greatly different in the location, number, function, role, and activity environment in which they are distributed. A rod cell is a cell for detecting an object such as a moving object to which a line of sight should be directed, and is distributed around the visual field (peripheral vision). Rod cells work in dark environments (dark vision). On the other hand, pyramidal cells are cells for judging detailed information and identifying and recognizing objects, and are distributed at the center of the visual field (central vision). Cone cells work in a bright environment (photopic vision). In other words, the human eye feels light from a bright place to a dark place as both photoreceptor cells (cones and rods) complement each other.

  The environment during night driving is not as bright as daytime (not photopic). In addition, the front lamp irradiates the front, so it is not dark (not a dark place). That is, the environment during night driving is a state of twilight vision between the photopic vision and the scotopic vision (a state where both the cone and the rod are activated). The adaptation illuminance is about 1 [lx].

  FIG. 33 shows the relative luminous sensitivity V (λ) in photopic vision and the specific luminous sensitivity V ′ (λ) in scotopic vision. The visual sensitivity changes from photopic vision to scotopic vision through twilight vision. It represents that the peak of the curve shifts to the short wavelength side. This peak shift occurs due to the difference in spectral sensitivity between the cone and the rod.

  The inventors of the present application have conducted studies in consideration of the visual characteristics of the human eye, and as a result, if the energy component on the short wavelength side (blue light) is increased in a dark environment during night driving, We thought that somatic cells could be stimulated efficiently, and it would be possible to speed up awareness in peripheral vision.

  As a result of various experiments and repeated examinations, in the dark environment during night driving, as the short wavelength side energy component (blue light) increases, the perception in peripheral vision becomes faster (reaction) Based on this finding, the present invention has been completed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicular headlamp that can speed up awareness in peripheral vision in a dark environment during night driving.

In order to solve the above problems, the invention described in claim 1 is a white light source including a first light emitting unit using a semiconductor light emitting element and a second light emitting unit using the semiconductor light emitting element, a reflective surface, and / or Or a vehicle headlamp comprising an optical system that includes a lens, irradiates light from the white light source forward, and forms a predetermined light distribution pattern on a virtual vertical screen facing the front of the vehicle. The distance between the central point of the first light emitting unit or the first condensing point of the irradiation light from the first light emitting unit and the focal point of the optical system is D1, and the central point of the second light emitting unit or the second light emission. When the distance between the second condensing point of the irradiation light from the unit and the focal point of the optical system is D2, there is a relationship of D1 <D2, and the predetermined light distribution pattern is forward through the optical system. A first light distribution pattern formed by the light emitted from the first light emitting unit; A second light distribution pattern formed in a state of being superimposed on the first light distribution pattern by light irradiated forward as light spreading to one side in the horizontal direction via the optical system, and at least A light / dark boundary on one end side in the horizontal direction of the second light distribution pattern is located outside a light / dark boundary on one end side in the horizontal direction of the first light distribution pattern, and the second light emission. parts, the S / P ratio than the first light-emitting portion is rather high, the white light source, a ceramic substrate, an outer frame surrounding an edge on the ceramic substrate, and a recess surrounded by the outer frame, gallium nitride At least two semiconductor light-emitting elements made of a system semiconductor, the two semiconductor light-emitting elements are disposed in the recess, and a separation wall is disposed between the two semiconductor light-emitting elements. One half of the semiconductor light emitting devices The body light emitting element is covered with a phosphor containing layer to constitute the first light emitting part, and the other semiconductor light emitting element of the two semiconductor light emitting elements is covered with a phosphor containing layer and the second light emitting part. characterized in that it constitutes a.

According to the first aspect of the present invention, the light from the second light emitting unit having a higher S / P ratio than the first light emitting unit is blurred using the difference in the degree of coincidence between the focal point of the optical system and each light emitting unit. By making the irradiation area wider than the light from the first light emitting part, outside of the light / dark boundary on one end side in the horizontal direction of the first light distribution pattern formed by the light from the first light emitting part (vehicle The front peripheral region) can be irradiated with light from the second light emitting unit having a higher S / P ratio than the first light emitting unit. As a result, it is possible to configure a vehicle headlamp that can speed up awareness in peripheral vision in a dark environment during night driving .

  When the central region is irradiated with light emitted from a light source having the same S / P ratio as that of the second light emitting unit, which has a higher S / P ratio than the first light emitting unit, a feeling of glare (glare) is given to the oncoming vehicle.

  According to the first aspect of the present invention, the center region is irradiated with light emitted from the first light emitting unit having an S / P ratio lower than that of the second light emitting unit. Compared to the case where the light emitted from the light source having the P ratio is applied to the central region, it is possible to suppress the oncoming vehicle from being dazzled (glare).

  As described above, according to the first aspect of the present invention, it is possible to suppress the oncoming vehicle from being dazzled (glare) and to be noticed in peripheral vision in a dark environment during night driving. Can be accelerated.

  The invention according to claim 2 is the invention according to claim 1, wherein the S / P ratio of the first light emitting part is less than 2.0, and the S / P ratio of the second light emitting part is 2.0. It is characterized by the above.

  According to the invention described in claim 2, by using the difference in the degree of coincidence between the focal point of the optical system and each light emitting part, the light from the second light emitting part having an S / P ratio of 2.0 or more is blurred, One end in the horizontal direction of the first light distribution pattern formed by the light from the first light emitting unit by making the irradiation area wider than the light from the first light emitting unit having an S / P ratio of less than 2.0 It becomes possible to irradiate the outside (peripheral area in front of the vehicle) with the light from the second light emitting unit having an S / P ratio of 2.0 or more from the light / dark boundary on the part side. As a result, it becomes possible to speed up awareness in peripheral vision in a dark environment during night driving.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the optical system includes a reflecting surface of a paraboloidal system whose focal point is set at or near the first light emitting unit, The distance between the central point of the first light emitting unit and the focal point of the reflecting surface of the rotary paraboloid system, which is the focal point of the optical system, is D1, and the central point of the second light emitting unit and the focal point of the optical system. When the distance from the focal point of the reflecting surface of the paraboloidal system is D2, there is a relationship of D1 <D2.

  According to the third aspect of the present invention, it is possible to configure a reflector type (reflective type) vehicle headlamp capable of speeding up the awareness of peripheral vision in a dark environment during night driving. .

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the optical system includes a projection lens, a first focal point set at or near the first light emitting unit, and a second focal point The projection lens, which includes a rear ellipsoidal reflecting surface set at or near the rear focal point of the projection lens, and is the first condensing point of the irradiation light from the first light emitting unit and the focal point of the optical system When the distance from the rear focal point is D1, and the distance between the second focal point of the irradiation light from the second light emitting unit and the rear focal point of the projection lens, which is the focal point of the optical system, is D2. , D1 <D2.

  According to the fourth aspect of the present invention, it is possible to configure a projector-type vehicle headlamp capable of speeding up the awareness of peripheral vision in a dark environment during night driving.

  According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the optical system includes a projection lens having a rear focal point set at or near the first light emitting unit, and the first light emission. The distance between the central point of the projection unit and the rear focal point of the projection lens that is the focal point of the optical system is D1, and the central point of the second light emitting unit and the rear focal point of the projection lens that is the focal point of the optical system When the distance of D2 is D2, there is a relationship of D1 <D2.

  According to the fifth aspect of the present invention, it is possible to configure a direct projection type (direct-lighting type) vehicle headlamp capable of speeding up the awareness of peripheral vision in a dark environment during night driving. Become.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the concave portion is divided into two concave portions by the separation wall, and the one semiconductor light emitting element is one of the two concave portions. The other semiconductor light emitting device is disposed in the other of the two recesses, and the one semiconductor light emitting device and the other semiconductor light emitting device are located between the separation walls. It is characterized by being adjacent to each other.

According to the sixth aspect of the present invention, it is possible to configure a vehicle headlamp capable of speeding up the awareness of peripheral vision in a dark environment during night driving.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the concave portion includes a central concave portion surrounded by the inner frame by an inner frame serving as the separation wall disposed inside the outer frame. And an annular recess surrounded by the inner frame and the outer frame, the one semiconductor light emitting element is disposed in the central recess, and the other semiconductor light emitting element is the annular recess. It is arranged inside.

According to the seventh aspect of the present invention, it is possible to configure a vehicle headlamp capable of speeding up awareness in peripheral vision in a dark environment during night driving.

  As described above, according to the present invention, it is possible to provide a vehicular headlamp that can speed up awareness in peripheral vision in a dark environment during night driving.

It is a block diagram of the apparatus used for Experiment 1. FIG. 6 is a graph showing the S / P ratio of the light source used in Experiment 1. It is a spectral distribution of each light source used in Experiment 1. (A) Configuration example of light source having S / P ratio of 2.0 or more, (b) Configuration example (modification example) of light source having S / P ratio of 2.0 or more. It is a spectral distribution of LED5500K (new1) used for Experiment 1. FIG. It is a spectral distribution of LED5500K (new2) used for Experiment 1. FIG. It is an example of the spectral distribution of a light source with high awareness in peripheral vision predicted from the shape of visibility. It is the graph which plotted the measurement result (average value) of Experiment 2 on the coordinate system of S / P ratio on a horizontal axis and reaction time RT and an overlook rate on a vertical axis. The horizontal axis is an S / P ratio, and the vertical axis is a graph in which the measurement results of Experiment 2 (the average value of the reaction time RT and the average value of the miss rate) are drawn in the coordinate system of the reaction time RT and the miss rate. It is a figure for demonstrating the environment where the experiment 2 was performed. It is a figure for demonstrating the environment where the experiment 3 was performed. (A) The horizontal axis is the S / P ratio, the vertical axis is the coordinate system of the evaluation scale, and the evaluation value (average value) of Japanese in Experiment 3 is plotted. (B) The horizontal axis is the S / P ratio, the vertical axis. It is the graph which plotted the evaluation value (average value) of the American of Experiment 3 on the coordinate system whose axis is the evaluation scale. It is a block diagram of the apparatus used for the experiment 4. FIG. It is the graph which plotted the measurement result (average value) of Experiment 4 in the coordinate system of a horizontal axis on S / P ratio and a vertical axis | shaft on a feeling of brightness. It is the graph which plotted the measurement result (average value) of Experiment 5 in the coordinate system of the horizontal direction distance from the vehicle center in the left-right direction, and the vertical axis in the front distance from the vehicle front. It is the graph which plotted the measurement result (average value) of Experiment 5 in the coordinate system of the horizontal direction from the vehicle center in the left-right direction and the vertical axis in the illuminance. It is an example of a light distribution pattern (screen light distribution) that is noticed faster in peripheral vision. It is an example of a light distribution pattern (road surface light distribution) that is noticed faster in peripheral vision. It is an example of the light distribution pattern (driver | operator's viewpoint) which notices quickly by peripheral vision. It is the figure which measured the driver | operator's eyes | visual_axis position (eye point). It is a figure for demonstrating relationships, such as central vision, peripheral vision, a cone, and a rod. It is a figure for demonstrating that it becomes possible to accelerate | stimulate the recognition with respect to objects, such as a pedestrian who exists in a peripheral visual field, at the time of the right turn (or at the time of a left turn) in an intersection in the dark environment at the time of night driving. (A) A predetermined light distribution pattern PL (screen arrangement) that is formed by light irradiated forward from a vehicle lamp unit 44L, which will be described later, disposed on the “left side” of the front portion of the vehicle and that is quickly noticed in peripheral vision. (B) is a cross-sectional view of the vehicle lamp unit 44L disposed on the “left side” of the front portion of the vehicle, cut along a horizontal plane including its optical axis. (A) A predetermined light distribution pattern PR (screen distribution) that is formed by light emitted forward from a vehicle lamp unit 44R, which will be described later, disposed on the “right side” of the front portion of the vehicle and that is quickly noticed in peripheral vision. (B) is a cross-sectional view of the vehicle lamp unit 44R disposed on the “right side” of the front portion of the vehicle, cut along a horizontal plane including the optical axis thereof. FIG. 26A is a front view of a white light source used for forming predetermined light distribution patterns PL and PR that are quickly noticed in peripheral vision, and FIG. 25B is a cross-sectional view taken along line AA in FIG. (A) (b) It is an example of light emission parts 24a and 24b using a laser light source as semiconductor light emitting element 18a. (A) A cross-sectional view of the vehicle lamp unit 48L (or 48R) disposed on the left side (or right side) of the front portion of the vehicle, cut along a vertical plane including its optical axis, (b) the left side of the front portion of the vehicle (or It is sectional drawing which cut | disconnected the vehicle lamp unit 54L (or 54R) arrange | positioned on the right side at the perpendicular | vertical surface containing the optical axis. (A) is a front view of a white light source used to form the light distribution patterns PL and PR that are quickly noticed in peripheral vision, (b) a cross-sectional view taken along line AA in FIG. It is BB sectional drawing of 28 (a). It is an example of the light distribution pattern (screen light distribution) of the conventional vehicle headlamp, (a) The light distribution pattern (road surface light distribution) of the conventional vehicle headlamp. (A) It is explanatory drawing of a driver | operator's central vision and peripheral vision, (b) It is a figure for demonstrating the relationship of a driver | operator's central vision, peripheral vision, a cone, a rod, etc. It is a flowchart for demonstrating the flow until a driver | operator recognizes the target object (pedestrian, obstacle, etc.) which exists in a peripheral visual field. It is the table | surface which summarized and contrasted the characteristics of peripheral vision and central vision. Specific luminous sensitivity V (λ) in photopic vision and specific luminous sensitivity V ′ (λ) in dark vision.

  Hereinafter, a vehicle headlamp according to an embodiment of the present invention will be described with reference to the drawings.

  The inventors of the present application have examined the visual characteristics of the human eye, and as a result, if the energy component on the short wavelength side (blue light) is increased in a dark environment during night driving, We thought that cells could be stimulated efficiently, and it would be possible to speed up awareness in peripheral vision.

  As a result of various experiments and repeated examinations, in the dark environment during night driving, as the short wavelength side energy component (blue light) increases, the perception in peripheral vision becomes faster (reaction) Based on this finding, the present invention has been completed.

  First, Experiments 1 to 5 performed by the inventors of the present application will be described.

  In the following experiment, the S / P ratio was used as an index representing the ratio of the energy component (blue color light) on the short wavelength side. The S / P ratio is expressed by the following equation. However, S (λ) is the spectrum of the light source, V (λ) is the specific luminous sensitivity in photopic vision, and V ′ (λ) is the specific luminous sensitivity in dark vision.

  The S / P ratio is obtained by measuring a spectrum of light emitted from a light source to be measured using a known measuring device (for example, a spectral radiance meter) and calculating using the above equation.

  Conventionally, in a vehicle headlamp, a light source having an S / P ratio of 2.0 or higher has not been used, and light from a light source having an S / P ratio of 2.0 or higher is detected in a dark environment during night driving. It has not been known at all how it affects the visual perception (= rod = scotopic sensitivity).

  Table 1 below shows the S / P ratio of a light source of a general vehicle headlamp measured by the inventors of the present application. A light source having a higher S / P ratio indicates that there are more energy components on the short wavelength side (light of blue color).

  Each light source in Table 1 is a light source used as a light source for a vehicle headlamp that is actually mounted on a commercially available vehicle. Referring to Table 1, it can be seen that the S / P ratio of the light source of a general vehicle headlamp is about 1.5 to 1.8.

  Halogen bulbs and HID bulbs are difficult to change the S / P ratio due to their structures, and the S / P ratios are approximately 1.46 and 1.75 shown in Table 1, respectively.

  Each LED in Table 1 is a white LED having a structure in which a blue LED element and a yellow phosphor such as YAG are combined. The white LED of this structure is adjusted in the concentration of the yellow phosphor so that the emission color meets the white range on the CIE chromaticity diagram specified by the law and looks natural to the driver's eyes. ing. In addition, the white range on the CIE chromaticity diagram specified by law is the coordinate value (0.31,0.28), (0.44, 0.38), (0.50, 0.38), (0.50, 0.44), (0.455, 0.44), ( It is the range surrounded by the straight line connecting 0.31,0.35).

  When the S / P ratio is less than 1.5, it is difficult for the white LED having the above structure to satisfy the white range on the CIE chromaticity diagram defined by law. Therefore, the lower limit of the S / P ratio is around 1.5. On the other hand, if the S / P ratio is up to about 2 (about 1.95), it is possible to satisfy the white range on the CIE chromaticity diagram specified by the law, but the S / P ratio is 1.8. If it approaches 2 and the yellow light is reduced, it becomes a bluish light and looks unnatural to the driver's eyes. Further, when the S / P ratio exceeds 1.8 and approaches 2, the efficiency decreases (the luminous flux decreases), and the brightness required for the light source of the vehicle headlamp cannot be secured. Therefore, the upper limit of the S / P ratio of the white LED having the above structure is about 1.8 from the viewpoint of constructing a highly efficient vehicle headlamp that looks natural to the driver's eyes.

  As described above, the S / P ratio of the light source of a general vehicle headlamp is conventionally about 1.5 to 1.8, and a light source having an S / P ratio of 2.0 or more is not used. Knowing how light from a light source with an S / P ratio of 2.0 or higher affects the awareness of peripheral vision (= enclosure = dark vision sensitivity) in a dark environment during night driving It was not done.

[Experiment 1]
The inventors of the present application have noticed that the S / P ratio (especially S / P ratio of 2.0 or more) is noticed in peripheral vision (= enclosure = dark vision sensitivity) in a dark environment during night driving. The following experiment was conducted in order to confirm the influence.

  FIG. 1 is a configuration diagram of the apparatus used in Experiment 1, and FIG. 2 is a graph showing the S / P ratio of the light source used in Experiment 1.

  In the experiment, an apparatus having the configuration shown in FIG. 1 was used, and a total of seven light sources having different correlated color temperatures and different S / P ratios as shown in Table 2 and FIG.

  FIG. 3 shows the spectral distribution of each light source used in Experiment 1. TH represents a halogen bulb, and HID represents a HID bulb. A number (for example, 4500K) attached to the side of the LED represents the correlated color temperature.

  LED4500K, LED5500K, and LED6500K are white LEDs with a combination of blue LED elements and yellow phosphors, and the correlated color temperature and S / P ratio are adjusted as shown in Table 2 by adjusting the concentration of yellow phosphors. did.

  FIG. 4A is a structural example of a light source (LED5500K (new1), LED5500K (new2)) having an S / P ratio of 2.0 or more.

  As shown in FIG. 4A, the LEDs 5500K (new1) and LED5500K (new2) are white LEDs having a structure in which a blue LED element B, a red LED element R, and a green phosphor G are combined. The S / P ratio was adjusted as shown in Table 2 by adjusting the green light to increase green light. The green phosphor G covers the blue LED element B and the red LED element R, and is excited by the blue light emitted from the blue LED element B to emit green light. When green light increases, the emission color becomes blue-green, which deviates from the white range on the CIE chromaticity diagram defined by law. Therefore, by adjusting the output by adding the red LED element R, the emission color was adjusted to be within the white range on the CIE chromaticity diagram defined by the law.

  The LED 5500K (new1) and the LED 5500K (new2) were adjusted so that the spectral distribution had a shape close to the spectral distribution of the light source that is predicted to be highly noticeable in peripheral vision.

  FIG. 5 shows the spectral distribution of the LED 5500K (new1), and FIG. 6 shows the spectral distribution of the LED 5500K (new2). FIG. 7 is an example of a spectral distribution of a light source with high awareness in peripheral vision predicted from the shape of visibility. According to the light source shown in FIG. 7, the green phosphor excited by blue light from the blue LED element (see numeral 1 in FIG. 7) and blue light from the blue LED element (see numeral 1 in FIG. 7). The white light is realized by the green light (see circle numeral 2 in FIG. 7) and the red light from the red LED element (see circle numeral 3 in FIG. 7). According to the spectral distribution shown in FIG. 7, the circle number 2 in FIG. 7 matches the visibility curve, so that it is possible to feel the brightness efficiently.

  5 and 6, the spectral distributions of the LEDs 5500K (new1) and the LED 5500K (new2) have a shape close to the spectral distribution of the light source predicted to be highly noticeable in the peripheral vision shown in FIG. I understand.

  The experiment was performed according to the following procedure. First, as shown in FIG. 1, while the subject is gazing at the display (in which hiragana is displayed) installed at a position 2 m in front and reading the displayed characters, the left (or right) with respect to the front. Randomly presented gray color materials irradiated by light sources adjusted to constant luminance (1, 0.1, 0.01 [cd / m2]) at 30 °, 45 °, 60 °, and 75 ° positions. .

  The time from when the light source is turned on (after white light is presented) until the subject who notices the presentation light (the reflected light from the gray color material) presses the button at hand (reaction time RT) Was measured. The above was measured for each light source.

  Note that the brightness setting values of the light source used in the experiment are 1, 0.1, and 0.01 [cd / m2], and the background brightness is 1 [cd / m2]. There are 4 subjects under 45 years old and 4 people over 45 years old.

  As a result of analyzing the measurement results, the inventors of the present application have found that the reaction rate decreases as the S / P ratio increases at the age of 45 years or older, and the miss rate decreases, that is, the S / P ratio at the age of 45 years or older. It has been found that as the P ratio increases, awareness in peripheral vision becomes faster.

  8 and 9 show the measurement results. FIG. 8 is a graph in which the measurement result (average value) is plotted in the coordinate system of the S / P ratio on the horizontal axis and the reaction time RT and the miss rate on the vertical axis. Note that the miss rate is the rate at which 2 seconds or more have passed since the subject noticed the presentation light after turning on the light source. The numbers in FIG. 8 are the coefficient of determination for each data group. FIG. 9 is a graph in which the measurement result (average value of reaction time RT, average value of miss rate) is drawn in the coordinate system of the S / P ratio on the horizontal axis and the reaction time RT and the miss rate on the vertical axis.

  Referring to FIG. 8, the reaction rate decreases as the S / P ratio increases to 2.0 or more at the age of 45 years or older, and the miss rate decreases, that is, the S / P ratio is 2 at the age of 45 years or older. It can be seen that the perception in peripheral vision becomes faster as the value increases to 0 or more.

  Based on this knowledge, light emitted from a light source having a S / P ratio of 2.0 or more is irradiated to the peripheral area in front of the vehicle, thereby speeding up awareness in peripheral vision in a dark environment during night driving. It becomes possible to configure a vehicular headlamp (the reaction speed RT is shortened and the miss rate is reduced). Under the age of 45 years, even when the S / P ratio increases, the reaction time and the miss rate are almost flat, and no correlation is seen between the two.

  Also, referring to FIG. 8, it can be seen from the correlation between the S / P ratio and the miss rate that the difference in awareness due to age is eliminated when the S / P ratio is 2.5 (or 2.5 or more).

  Based on this knowledge, light emitted from a light source with a S / P ratio of 2.5 (or more than 2.5) is irradiated on the surrounding area in front of the vehicle, so that it depends on age in a dark environment during night driving. It is possible to configure a vehicle headlamp that has no noticeable difference.

  In addition, comparing LED 5500K (new1) and LED5500K (new2) in FIG. 9 with other light sources, LED5500K (new1) and LED5500K (new2) have a reaction time RT under 45 years old and a reaction time RT over 45 years old. (And the difference between the missed rate under 45 years old and the missed rate above 45 years old) is small.

  In addition, comparing LED 5500K (new1) and LED5500K (new2) in FIG. 9 with other light sources, LED5500K (new1) and LED5500K (new2) have a short reaction time RT of 45 years or older and a low oversight rate. I understand.

[Experiment 2]
The inventors of the present application have noticed that the S / P ratio (especially an S / P ratio of 2.0 or more) is noticed in peripheral vision (= enclosure = dark vision sensitivity) in a dark environment during actual night driving. The following experiment was conducted in order to confirm the influence.

  FIG. 10 is a diagram for explaining the environment in which Experiment 2 was performed.

  In the experiment, as shown in FIG. 10, assuming a vehicle turning right at the intersection, the vehicle V was stopped in the intersection. And the pedestrian M was located in front of the pedestrian crossing in the advancing direction of the vehicle V which turns right at the intersection (the blind spot position of the driver D). A total of three light sources having different S / P ratios (S / P ratios: 1.5, 2.0, and 2.5) were used as light sources for the vehicle headlamp.

  A light source having an S / P ratio of 1.5 and 2.0 is a white LED having a structure in which a blue LED element and a yellow phosphor are combined. By adjusting the concentration of the yellow phosphor, the S / P ratio is set to 1. Adjusted to 5, 2.0.

  The light source having an S / P ratio of 2.5 is a white LED having a structure in which a blue LED element, a red LED element, and a green phosphor are combined. By adjusting the concentration of the green phosphor, the S / P ratio is set to 2. Adjusted to 5.

  The experiment was performed according to the following procedure. The time until the driver D notices the pedestrian M after the pedestrian M starts walking from the front of the pedestrian crossing to the opposite side was measured. The above was measured for each light source. There are 4 subjects under 45 years old and 4 people over 45 years old.

  The measurement results are shown in Table 3 below.

  Referring to Table 3, it can be seen that the walking distance until the pedestrian is noticed becomes shorter as the S / P ratio increases, both under 45 and above 45.

  For example, when a light source with an S / P ratio of 1.5 and a light source with an S / P ratio of 2.5 are compared with a light source with an S / P ratio of 2.5, the light source with an S / P ratio of 2.5 may notice 26 cm faster. I understand. Assuming that the walking speed is 50 cm / second, a light source with an S / P ratio of 2.5 will be noticed 26/50 = 0.52 seconds faster. If the vehicle speed is assumed to be 1 m / s, the light source with an S / P ratio of 2.5 is stopped 52 cm before the pedestrian.

  Similarly, when comparing a light source with an S / P ratio of 1.5 and a light source with an S / P ratio of 2.0, the light source with an S / P ratio of 2.0 notices 13 cm faster for those under 45 years old. I understand. Assuming that the walking speed is 50 cm / second, a light source with an S / P ratio of 2.0 will be noticed 13/50 = 0.26 seconds faster. If the vehicle speed is assumed to be 1 m / s, the S / P ratio 2.0 light source will stop 26 cm before the pedestrian.

  On the other hand, when comparing a light source with an S / P ratio of 1.5 and a light source with an S / P ratio of 2.5 for a 45 year old or older, the light source with an S / P ratio of 2.5 may notice 30 cm faster. I understand. Assuming that the walking speed is 50 cm / second, a light source with an S / P ratio of 2.5 will be noticed 30/50 = 0.6 seconds faster. If the vehicle speed is assumed to be 1 m / s, the light source with an S / P ratio of 2.5 is stopped 60 cm before the pedestrian.

  Similarly, when comparing a light source with an S / P ratio of 1.5 and a light source with an S / P ratio of 2.0 for a 45 year old or older, the light source with an S / P ratio of 2.0 notices 14 cm faster. I understand. Assuming that the walking speed is 50 cm / second, a light source with an S / P ratio of 2.0 will be noticed 14/50 = 0.28 seconds faster. Assuming that the vehicle speed is 1 m / s, the S / P ratio 2.0 light source is stopped 28 cm before the pedestrian.

  As described above, in the dark environment during actual night driving, the walking distance (until the pedestrian is noticed) as the S / P ratio increases, regardless of whether it is under 45 or older. It has been confirmed that the number of seconds) becomes shorter and the vehicle can stop before the pedestrian, that is, as the S / P ratio increases, the perception in the peripheral vision becomes faster.

  The following Table 4 is a table summarizing the reaction time RT and overlook rate of 45 years or older for halogen bulbs, HID bulbs, and white LEDs. The light source having an S / P ratio of 2.5 is a white LED having a structure in which a blue LED element, a red LED element, and a green phosphor are combined. By adjusting the concentration of the green phosphor, the S / P ratio is set to 2. Adjusted to 5. There are 4 subjects under 45 years old and 4 people over 45 years old.

  Comparing halogen light bulbs with S / P ratio 2.5 light sources, S / P ratio 2.5 light sources with a S / P ratio of 2.5 shorten reaction time RT by 0.12 seconds and overlook rate decreased by 8% I understand that Also, referring to Table 4, the reaction time RT of a light source having an S / P ratio of 2.5 is 0.79 seconds, which is a generally known reaction time during vehicle operation (determined as dangerous). It can be seen that the time from 0.7 to 0.9 seconds is sufficiently satisfied.

[Experiment 3]
Conventionally, it has not been known at all how the S / P ratio affects the appearance of the label color.

  The inventors of the present application conducted the following experiment in order to confirm how the S / P ratio affects the appearance of the marker color in a dark environment during night driving.

  FIG. 11 is a diagram for explaining an environment in which Experiment 3 was performed.

  In the experiment, as shown in FIG. 11, a five-color color chart S (a typical five-color chart used for signs, that is, a color chart including white, red, green, blue, and yellow) 50 m ahead of the stopped vehicle V. Arranged. A total of five light sources having different S / P ratios shown in Table 5 below were used as light sources for the vehicle headlamp.

  LED4500K, LED5500K, and LED6500K are white LEDs with a structure combining a blue LED element and a yellow phosphor, and the correlated color temperature and S / P ratio are adjusted as shown in Table 5 by adjusting the concentration of the yellow phosphor. did.

  The experiment was performed according to the following procedure. Irradiation with 5 color charts (white, red, green, blue, yellow) (illuminance: about 10 [lx]), subjective evaluation scale (3: how to see when illuminated with HID bulb, : Evaluate the appearance of the five-color color chart by using the following:: Visibility between 2: 1 and 3: 5: Clear clarity, 4: 3 and 5 did. The above was evaluated for each light source. The subjects were 16 Japanese and 43 Americans.

  As a result of analyzing the evaluation results, the inventors of the present application found that a light source with a high S / P ratio clearly appears regardless of race, and a light source with a high S / P ratio (especially the S / P ratio is 1.8 or more light sources) have found that white, blue and green are clear.

  FIG. 12A and FIG. 12B show the evaluation results. FIG. 12A is a graph in which the horizontal axis represents the S / P ratio, and the vertical axis represents the evaluation value (average value) of the Japanese in the coordinate system of the evaluation scale. FIG. The ratio and the vertical axis are graphs in which American evaluation values (average values) are plotted in the coordinate system of the evaluation scale.

  Referring to FIGS. 12 (a) and 12 (b), the evaluation value for the light source having a high S / P ratio is higher than the standard 3, and the light source having a high S / P ratio can be clearly seen regardless of race. It can also be seen that a light source having a high S / P ratio (particularly a light source having an S / P ratio of 1.8 or more) makes white, blue and green clear.

  Based on this knowledge, by irradiating the sign with light emitted from a light source with an S / P ratio of 1.8 or more, the sign can be clearly seen in a dark environment during night driving. An illumination lamp can be configured.

[Experiment 4]
Conventionally, it has not been known at all how the S / P ratio affects the feeling of brightness (luminance difference between the reference light source and the test light source).

  The inventors of the present application conducted the following experiment in order to confirm how the S / P ratio affects the feeling of brightness in a dark environment during night driving.

  FIG. 13 is a block diagram of the apparatus used in Experiment 4.

  In the experiment, an apparatus having the configuration shown in FIG. 13 was used, and a total of three white LEDs having different correlated color temperatures and S / P ratios shown in Table 6 below were used as test light sources.

  LED3800K, LED5300K, and LED5800K are white LEDs with a combination of blue LED elements and yellow phosphors, and the correlated color temperature and S / P ratio are adjusted as shown in Table 6 by adjusting the concentration of yellow phosphors. did.

  The experiment was performed according to the following procedure. Look at the test light source with one eye and the reference light source with the other eye, and have the subject adjust the current value of the test light source so that the test light source has the same brightness as the reference light source. The spectral radiance of the light source was measured and the luminance difference between the reference light source and the test light source was calculated. The above was measured for each test light source and reference light source. There are 16 subjects.

  As a result of analyzing the measurement results, the inventors of the present application have found that the brightness of white LEDs increases as the S / P ratio increases.

  In FIG. 14, the horizontal axis represents the S / P ratio, and the vertical axis represents the brightness difference between the reference light source and the test light source as a measurement result in the coordinate system of the brightness difference when the brightness of the reference light source and the test light source are felt to be the same. It is the graph which plotted (average value).

  Referring to FIG. 14, the luminance difference is negative. This indicates that the test light source obtains the same brightness with a lower luminance value than the reference light source. Therefore, as shown in FIG. 14, the graph decreases to the right as the S / P ratio increases. As the S / P ratio of white LEDs increases, the feeling of brightness (brightness difference between the reference light source and the test light source) increases, and the white LEDs are about 13 to 26% for halogen bulbs and about 13% for HID bulbs. It can be seen that the brightness feeling of 3 to 17% (luminance difference between the reference light source and the test light source) increases.

[Experiment 5]
The inventors of the present application conducted the following experiment in order to confirm how the S / P ratio affects the feeling of brightness in a dark environment during actual night driving.

  In the experiment, a total of three light sources having different correlated color temperatures and different S / P ratios shown in Table 8 below were used as light sources for the vehicle headlamp.

  LED 4500K and LED 5500K are LEDs having a structure in which a blue LED element and a yellow phosphor are combined. By adjusting the concentration of the yellow phosphor, the correlated color temperature and the S / P ratio are adjusted as shown in Table 8. .

  The experiment was performed according to the following procedure. Irradiate the area in front of the vehicle (the area on the road surface in front of the vehicle in the own lane) with the same light distribution pattern, and report the area where the driver (subject) feels the brightest. It was measured. The above was measured for each light source. There are 5 subjects.

  As a result of analyzing the measurement results, the inventors of the present application do not widen the range in which the brightness is felt even if the illuminance increases, and the range in which the brightness is felt increases as the S / P ratio increases. It has been found that the brightness feeling of the area correlates with the S / P ratio, not the illuminance, and it is possible to increase the brightness feeling of the area in front of the vehicle by increasing the S / P ratio instead of the illuminance.

  15 and 16 show the measurement results. FIG. 15 is a graph in which measurement results (average values) are plotted in a coordinate system in which the horizontal axis is the distance in the left-right direction from the vehicle center and the vertical axis is the front distance from the front of the vehicle. FIG. 16 is a graph in which measurement results (average values) are plotted in a coordinate system in which the horizontal axis is the distance in the left-right direction from the vehicle center and the vertical axis is illuminance.

  Referring to FIGS. 15 and 16, the LED 5500K having a high S / P ratio has a wide range in which the LED 5500K feels brighter than other light sources, and the illuminance is equal or less than that. It can be seen that the range illuminated by the LED 5500K having a high P ratio is wider than the other light sources. That is, the feeling of brightness in the front area of the vehicle correlates with the S / P ratio, not the illuminance, and it becomes possible to increase the feeling of brightness in the front area of the vehicle by increasing the S / P ratio instead of the illuminance. I understand that.

  Based on this knowledge, the vehicle emits light emitted from a light source having an S / P ratio of 2.0 or more to the front front area of the vehicle without increasing the illuminance in a dark environment during night driving. It becomes possible to enhance the brightness of the front front area (area on the road surface in front of the vehicle in the own lane).

[Light distribution pattern example 1 for quicker perception in peripheral vision]
The inventors of the present application examined a light distribution pattern that is quickly noticed in peripheral vision based on the knowledge obtained from each of the experiments 1-5.

  Hereinafter, a light distribution pattern example 1 that the inventors noticed in peripheral vision, which has been studied, will be described.

  FIG. 17 is an example of a light distribution pattern (screen light distribution) that is noticed quickly in peripheral vision, FIG. 18 is an example of a light distribution pattern (road surface light distribution) that is quickly noticed in peripheral vision, and FIG. It is an example of the light distribution pattern (driver | operator's viewpoint) which notices quickly.

  A light distribution pattern P shown in FIG. 17 is a light distribution pattern formed on a virtual vertical screen (disposed approximately 25 m ahead from the front of the vehicle) facing the front of the vehicle. The central region A1 and the peripheral region A2 , An intermediate area A3 and a front area A4. Each of the areas A1 to A4 is arranged at the position shown in FIG. 18 on the road surface, and is arranged at the position shown in FIG. 19 from the viewpoint of the driver.

  The center area A1 is an area corresponding to the central visual field (cone) of the driver who is gazing at a distant place (for example, the vanishing point).

  In this embodiment, as the center area A1, as shown in FIG. 17, a high light intensity area (referred to as a hot zone) including an intersection of a horizontal line and a vertical line on the virtual vertical screen, for example, on the virtual vertical screen Surrounded by a straight line connecting the left 5 ° up 2 ° position, the left 5 ° down 2 ° position, the right 5 ° down 2 ° position, the right 5 ° up 2 ° position, and the left 5 ° up 2 ° position. Selected areas.

  The reason why the central area A1 is set to 5 ° to the left and right is that the driver's line-of-sight position (eye point) is concentrated in a range of 5 ° to the left and right. FIG. 20 is a diagram in which the driver's line-of-sight position (eye point) is measured, and each black dot in FIG. 20 represents the line-of-sight position of the driver during driving. Referring to FIG. 20, it can be seen that the black spots are concentrated in the range of 5 ° to the left and the driver's line-of-sight position (eye point) is concentrated in the range of 5 ° to the left and right.

  The reason why the central area A1 is set to 2 ° in the vertical direction is to mainly satisfy the brightness required by the law and form a light distribution with high distant visibility.

The center area A1 may be an area corresponding to the center visual field (cone) of the driver who is gazing at a distant place (for example, the vanishing point). It is not limited to the 2 ° region.

  The light source that irradiates the central region A1 is a light source having a lower S / P ratio than the light source that irradiates the peripheral region A2 (in this embodiment, a light source having an S / P ratio of 2.0 is exemplified) (in this embodiment). And a light source having an S / P ratio of 1.5). The reason is that if the central area A1 is irradiated with light emitted from a light source having the same S / P ratio as the light source that irradiates the peripheral area A2 (for example, a light source having an S / P ratio of 2.0), the oncoming vehicle is dazzled. This is to suppress a feeling of glare.

  The center area A1 is arranged on the road surface in an area 5 ° to the left and right with respect to the reference axis AX extending in the vehicle front-rear direction as shown in FIG. 18, and at the position shown in FIG. .

  As described above, the light source (in this embodiment, the S / P ratio is lower) than the light source that irradiates the peripheral area A2 (in this embodiment, a light source having an S / P ratio of 2.0 is exemplified). By irradiating the center area A1 in front of the vehicle with light emitted from a light source of 1.5), it is possible to suppress the oncoming vehicle from being dazzled (glare).

  The peripheral area A2 is an area corresponding to the peripheral visual field (housing) of the driver who is gazing at a distant place (for example, the vanishing point).

  In this embodiment, as the peripheral area A2, as shown in FIG. 17, both the left and right sides of the central area A1 on the virtual vertical screen, for example, a position 15 ° above 6 ° to the right and 6 ° above 80 ° to the right on the virtual vertical screen. Right region A2R surrounded by a straight line connecting a position of °, a position of 80 ° down to the right, 14 ° down to the right, 15 ° down to the right, 14 ° down to the right, and 15 ° up to the right. Select left region A2L surrounded by straight line connecting 6 ° position, left 80 ° up 6 ° position, left 80 ° down 14 ° position, left 15 ° down 14 °, left 15 ° up 6 ° position did.

  The reason why the right region A2R is set to the right 15 ° to the right 80 ° is that many rods are distributed in the range of 15 ° or more on the left and right, and this is stimulated. The reason why the left region A2L is set to 15 ° to 80 ° left is also the same. Referring to FIG. 21, it can be seen that the casings are widely distributed in a range of 15 ° or more on the left and right. FIG. 21 is a diagram for explaining the relationship between central vision, peripheral vision, cones, rods, and the like.

  The reason why the right region A2R is in the range of 6 ° to 14 ° is mainly to illuminate an object such as a pedestrian during a right turn at an intersection. The reason why the left region A2L is in the range of 6 ° to 14 ° is the same.

The peripheral area A2 may be an area corresponding to the peripheral visual field (enclosure) of the driver who is gazing at a distant place (for example, the vanishing point). It is not limited to the region of 80 ° (left 15 ° to left 80 °), upper 6 ° to lower 14 °.

  The light source that irradiates the peripheral area A2 is a light source having an S / P ratio of 2.0 or more (in the present embodiment, a light source having an S / P ratio of 2.0 is exemplified). The reason why the light source has an S / P ratio of 2.0 or higher is that as the S / P ratio increases to 2.0 or higher, the perception in peripheral vision becomes faster (the reaction speed becomes shorter and the missed rate decreases). (See Experiment 1 and Experiment 2) to speed up awareness in peripheral vision in a dark environment during night driving (reduce the reaction rate and reduce the miss rate).

  The peripheral area A2 is arranged on the road surface in an area of 15 ° right to 80 ° and 15 ° left to 80 ° left with respect to the reference axis AX extending in the vehicle longitudinal direction as shown in FIG. From the point of view, they are arranged at the positions shown in FIG.

  As described above, the light emitted from the light source having an S / P ratio of 2.0 or more is irradiated on the peripheral area A2 (A2R, A2L) in front of the vehicle, for example, in a dark environment during night driving. As shown in FIG. 22, it becomes possible to speed up the awareness of an object such as a pedestrian M present in the peripheral visual field at the time of a right turn (or a left turn) at an intersection.

  The intermediate area A3 is an area that covers an area through which a sign that moves relatively during traveling passes.

  In the present embodiment, as shown in FIG. 17, as the intermediate area A3, between the central area A1 and the peripheral area A2, for example, a position of 5 ° above the right 5 ° on the virtual vertical screen, 5 ° below the right Right region A3R surrounded by a straight line connecting a position of 1 °, a position of 15 ° to the right and a position of 2 ° to the right, a position of 15 ° to the right and a position of 3 ° to the right, and a position of 5 ° to the right and 5 ° to the right. A straight line connecting the left 15 ° up 3 ° position, the left 15 ° down 2 ° position, the left 5 ° down 1 ° position, the left 5 ° up 0.5 ° position, and the left 15 ° up 3 ° position The left region A3L surrounded by is selected.

  The reason for arranging the two areas of the right area A3R and the left area A3L is to illuminate the signs installed on both sides of the road.

  The reason why the trapezoidal shape in which the vertical width of the right region A3R is increased from the center toward the outside (from the right 5 ° to the right 15 °) is that the apparent height changes from low to high during traveling. This is to illuminate only the sign. The reason for making the left region A3L trapezoidal shape whose vertical width increases as it goes outward from the center (from 5 ° to 15 ° to the left) is also the same.

  The intermediate area A3 is not limited to the trapezoidal shape as long as it covers an area through which a sign that moves relatively during traveling passes from the viewpoint of the driver. For example, the intermediate area A3 may have a rectangular shape including the trapezoidal shape.

  The light source that irradiates the intermediate area A3 is a light source having an S / P ratio of 1.8 or more (in this embodiment, a light source having an S / P ratio of 1.8 is exemplified). The reason why the light source having an S / P ratio of 1.8 or more is that a light source having a high S / P ratio (particularly a light source having an S / P ratio of 1.8 or more) clearly shows white, blue, and green. This is because signs (particularly white, blue, and green) can be clearly seen in a dark environment during night driving based on (Experiment 3).

  The intermediate area A3 is arranged on the road surface in areas of 5 ° to right 15 ° and 5 ° to left 15 ° with respect to the reference axis AX extending in the vehicle longitudinal direction as shown in FIG. From the point of view, they are arranged at the positions shown in FIG.

  As described above, by irradiating light emitted from a light source having an S / P ratio of 1.8 or more to the intermediate area A3 (A3R, A3L) in front of the vehicle, a sign ( In particular, white, blue and green) can be clearly seen.

  The front area A4 is an area that covers a front area in front of the vehicle (an area on the road surface in front of the vehicle in the own lane).

  In the present embodiment, as the front area A4, as shown in FIG. 17, it is below the horizontal line on the virtual vertical screen (in front of the driver's lane from the viewpoint of the driver), for example, 9.4 ° to the left on the virtual vertical screen A region surrounded by a straight line connecting a position of 3 °, a position of 17 ° to the left and 8 ° to the bottom, a position of 16.7 ° to the bottom and 8 ° to the right, and a position of 3 ° to the bottom of 8.3 ° to the right was selected.

  The reason why the front area A4 has a trapezoidal shape with its width expanding as it goes vertically downward on the virtual vertical screen (from 3 degrees below to 8 degrees below) is to illuminate only the area on the road surface in front of the vehicle in the own lane (See FIG. 19).

  The foreground area A4 may be an area that covers an area in front of the vehicle (area on the road surface in front of the vehicle in the own lane), and is not limited to the trapezoidal shape. For example, the front area A4 may have a rectangular shape including the trapezoidal shape.

  The light source that irradiates the front area A4 is a light source having the same S / P ratio as 2.0 in the peripheral area A3 (in this embodiment, a light source having an S / P ratio of 2.0 is exemplified). The reason why the light source has an S / P ratio of 2.0 or more is that the brightness feeling in the front area of the vehicle correlates with the S / P ratio, not the illuminance, and the vehicle is increased by increasing the S / P ratio instead of the illuminance. Based on the knowledge that it is possible to increase the brightness of the front front area (see Experiments 4 and 5), the front front area of the vehicle is increased by increasing the S / P ratio instead of the illuminance in a dark environment during night driving. This is to increase the feeling of brightness.

  The front area A4 is arranged on the road surface in an area 5 to 15 m ahead of the vehicle and 3.5 m wide as shown in FIG. 18, and at the position shown in FIG. 19 from the viewpoint of the driver.

  As described above, by irradiating the front area A4 in front of the vehicle with light emitted from a light source having an S / P ratio of 2.0 or more, the vehicle does not increase in illuminance in a dark environment during night driving. It becomes possible to enhance the brightness of the front front area (area on the road surface in front of the vehicle in the own lane).

[Light distribution pattern example 2 for quicker perception in peripheral vision]
Hereinafter, a light distribution pattern example 2 in which the inventors will notice faster in peripheral vision will be described.

  FIG. 23A shows a predetermined light distribution pattern PL that is formed by light irradiated forward from a vehicle lamp unit 44L, which will be described later, disposed on the “left side” of the front portion of the vehicle, and that is quickly noticed in peripheral vision. It is an example of the elements on larger scale of (screen light distribution). FIG. 24A shows a predetermined light distribution pattern PR that is formed by light irradiated forward from a vehicle lamp unit 44R, which will be described later, disposed on the “right side” of the front portion of the vehicle, and that is quickly noticed in peripheral vision. It is an example of the elements on larger scale of (screen light distribution).

  The predetermined light distribution pattern PL and the predetermined light distribution pattern PR are symmetrical and have substantially the same shape. For this reason, hereinafter, the description will focus on the predetermined light distribution pattern PL, and description of the predetermined light distribution pattern PR will be omitted.

  A predetermined light distribution pattern PL shown in FIG. 23A is a light distribution pattern formed on a virtual vertical screen (disposed approximately 25 m ahead from the front of the vehicle) facing the front of the vehicle, and the central region A5L. The peripheral area A6L is included.

  The central area A5L is an area corresponding to the central visual field (cone) of the driver who is gazing at a distant place (for example, the vanishing point). For example, the central area A1 and the intermediate area A3 shown in FIG. Area).

  The light source that irradiates the center region A5L is a light source (S / P ratio is less than 2.0) that has a lower S / P ratio than the light source that irradiates the peripheral region A6L (S / P ratio is 2.0 or more). The reason is that when the center area A5L is irradiated with light emitted from a light source having the same S / P ratio as the light source that irradiates the peripheral area A6L (S / P ratio is 2.0 or more), the oncoming vehicle is dazzled ( This is to prevent glare).

  As described above, the light emitted from the light source (S / P ratio is less than 2.0) having a lower S / P ratio than the light source (S / P ratio is 2.0 or more) irradiating the peripheral area A6L is forward of the vehicle. By irradiating the center area A5L, it is possible to suppress the oncoming vehicle from being dazzled (glare).

  The peripheral area A6L is an area corresponding to the peripheral visual field (enclosure) of the driver who is gazing at a distant place (for example, the vanishing point), for example, the peripheral area A2L (or an area corresponding thereto) shown in FIG. is there.

  The light source that irradiates the peripheral area A6L is a light source having an S / P ratio of 2.0 or more. The reason why the light source has an S / P ratio of 2.0 or higher is that as the S / P ratio increases to 2.0 or higher, the perception in peripheral vision becomes faster (the reaction speed becomes shorter and the missed rate decreases). (See Experiment 1 and Experiment 2) to speed up awareness in peripheral vision in a dark environment during night driving (reduce the reaction rate and reduce the miss rate).

  As described above, by irradiating the peripheral area A6L in front of the vehicle with light emitted from a light source having an S / P ratio of 2.0 or more, as shown in FIG. 22, for example, in a dark environment during night driving. When turning right at the intersection (or when turning left), it becomes possible to speed up the awareness of the pedestrian M or the like existing in the peripheral visual field.

[Configuration example 1 of white light source]
Next, a configuration example 1 of a white light source used for forming the predetermined light distribution patterns PL and PR (see FIGS. 23A and 24A) that are noticed quickly in peripheral vision will be described.

  FIG. 25A is a front view of a white light source used to form predetermined light distribution patterns PL and PR (see FIGS. 23A and 24A) that are quickly noticed in peripheral vision. (B) is AA sectional drawing of Fig.25 (a).

  As shown in FIGS. 25A and 25B, the white light source 10 includes a first light emitting unit 24a using the semiconductor light emitting element 18a and a second light emitting unit 24b using the semiconductor light emitting element 18b. Contains.

  The white light source 10 includes a ceramic substrate 12 (for example, co-fired ceramic), an outer frame 14 that surrounds an edge on the ceramic substrate 12, a recess 16 that is surrounded by the ceramic substrate 12 and the outer frame 14, and at least two semiconductor light emitting elements. 18a, 18b and the like.

  The semiconductor light emitting elements 18a and 18b are light emitting diodes made of, for example, a gallium nitride based semiconductor, and are disposed in the recess 16 (upper surface of the ceramic substrate 12).

  A separation wall 20 is disposed between the semiconductor light emitting element 18a and the semiconductor light emitting element 18b. The recess 16 is divided into two recesses 16 a and 16 b by the separation wall 20. The semiconductor light emitting element 18a is disposed in one recess 16a (the upper surface of the ceramic substrate 12), and the semiconductor light emitting element 18b is disposed in the other recess 16b (the upper surface of the ceramic substrate 12). The semiconductor light emitting element 18a and the semiconductor light emitting element 18b are adjacent to each other with the separation wall 20 interposed therebetween. The height of the separation wall 20 is higher than the outer frame 14 by increasing the number of cera layers from the outer frame 14 in order to prevent light leakage. The reason why the separation wall 20 is made higher than the outer frame 14 is that the mold resin rises above the outer frame 14 due to surface tension even when the mold resin in a fluid state, for example, the wavelength conversion member 22a is filled in the recess 16a. However, it is possible to reduce light leaking to the other concave portion 16b side. Moreover, since the separation wall 20 is provided on the same ceramic substrate 12, the white light source 10 and the vehicle lamp unit can be reduced in size, which is preferable.

  The semiconductor light emitting element 18a (for example, a blue LED element) is covered with a wavelength conversion member 22a (for example, a phosphor-containing layer (yellow phosphor)) filled in the recess 16a, and the first light emitting section 24a (white LED light source). ).

  The wavelength conversion member 22a is a mixture of light excited by light from the semiconductor light emitting element 18a (for example, yellow light) and light from the semiconductor light emitting element 18a that transmits the wavelength conversion member 22a (for example, blue light). Emits white light.

  The first light emitting unit 24a adjusts the concentration of the wavelength conversion member 22a (for example, a yellow phosphor) so that the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, and the S / P The ratio is adjusted to less than 2.0 (for example, 1.5).

  The first light emitting unit 24a that irradiates the central region A5L has a lower S / P ratio (S / P ratio of 2) than the second light emitting unit 24b that irradiates the peripheral region A6L (S / P ratio is 2.0 or more). Less than 0). The reason for this is that if the central region A5L is irradiated with light having the same S / P ratio as that of the second light emitting unit 24b that irradiates the peripheral region A6L, the oncoming vehicle is given a glare (glare). Because.

  The S / P ratio of the first light emitting unit 24a is desirably 1.5 or more. The reason is that if the S / P ratio is less than 1.5, it is difficult to satisfy the white range on the CIE chromaticity diagram defined by the law.

  The first light emitting unit 24a may be a light source that has a light emission color that satisfies the white range on the CIE chromaticity diagram specified by law and has an S / P ratio of less than 2.0. It is not limited to the white LED light source of the structure which combined the containing layer (yellow fluorescent substance).

  For example, as shown in FIG. 4B, the first light emitting unit 24a may be a white LED light source having a structure in which a blue LED element B and a phosphor-containing layer (green and red phosphor GR) are combined. .

  The first light emitting unit 24a may be a white LED light source having a structure in which a red LED element, a green LED element, and a blue LED element are combined, or an ultraviolet or near ultraviolet LED element and a phosphor-containing layer (RGB phosphor). ) May be a white LED light source having a structure. Even in the white LED light source having these structures, by adjusting the concentration or the like of the wavelength conversion member 22a (for example, phosphor), the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, And it is possible to comprise the light source whose S / P ratio is less than 2.0.

  The first light emitting unit 24a is not limited to a white LED light source as long as the light emission color satisfies the white range on the CIE chromaticity diagram stipulated by law and the S / P ratio is less than 2.0. .

  For example, the first light emitting unit 24a absorbs a laser light source (for example, a laser diode (blue laser diode)) and a wavelength conversion member 22a (for example, laser light from the laser light source, converts the wavelength, and outputs light in a predetermined wavelength range. And a white laser light source having a structure in combination with a wavelength converting member such as a yellow phosphor that emits light. By using a laser light source as the semiconductor light emitting element 18a, it is possible to configure the first light emitting unit 24a having a small light emission area (closer to a point light source) and high brightness as compared with the case where a light emitting diode is used as the semiconductor light emitting element 18a. It becomes.

  FIG. 26A and FIG. 26B are examples of the first light emitting unit 24a using a laser light source as the semiconductor light emitting element 18a.

  FIG. 26A shows a first light emitting unit having a structure in which a semiconductor light emitting element 18a (laser light source) is disposed at a position separated from the wavelength converting member 22a, and the condenser lens 11 and the wavelength converting member 22a are disposed in front of the semiconductor light emitting element 18a. This is an example of 24a (white laser light source). In FIG. 26B, a semiconductor light emitting element 18a (laser light source) is disposed at a position spaced from the wavelength conversion member 22a, and a condensing lens 13 and a light guide 15 (for example, an optical fiber including a core and a cladding) are disposed in front of the semiconductor light emitting element 18a. ) Of the first light emitting unit 24a (white laser light source) having a structure in which the wavelength conversion member 22a is disposed on the light exit surface 15b of the light guide 15.

  The semiconductor light emitting element 18b is covered with a wavelength conversion member 22b filled in the recess 16b to form a second light emitting unit 24b (white LED light source).

  For example, the semiconductor light emitting element 18b is a blue LED element B and a red LED element R shown in FIG. 4A, and the wavelength conversion member 22b is a green phosphor G shown in FIG. The green phosphor G is excited by the blue light emitted from the blue LED element B and emits green light. When green light increases, the emission color becomes blue-green, which deviates from the white range on the CIE chromaticity diagram defined by law. Therefore, by adjusting the output by adding the red LED element R, the emission color is adjusted to be within the white range on the CIE chromaticity diagram defined by the law.

  The second light emitting unit 24b adjusts the concentration of the wavelength conversion member 22a (for example, a green phosphor) so that the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, and the S / P The ratio is adjusted to 2.0 or more (for example, 2.0).

  The 2nd light emission part 24b which irradiates peripheral region A6L is a light source whose S / P ratio is 2.0 or more. The reason is that as the S / P ratio increases to 2.0 or higher, the perception in peripheral vision becomes faster (the reaction speed becomes shorter and the miss rate decreases) (see Experiment 1 and Experiment 2). This is based on speeding up the awareness of peripheral vision in a dark environment during night driving (reducing the reaction speed and reducing the missed rate).

  The S / P ratio of the second light emitting unit is desirably 3.0 or less. The reason is that when the S / P ratio exceeds 3.0, it is difficult to satisfy the white range on the CIE chromaticity diagram defined by the law.

  From the correlation between the S / P ratio and the missed rate, based on the knowledge that the S / P ratio is 2.5 (or 2.5 or more) and there is no difference in awareness due to age (see Experiment 1), S / P By irradiating the surrounding area with light emitted from a light source with a P ratio of 2.5 or 2.5 to 3.0, there is no difference in awareness due to age in a dark environment during night driving. An illumination lamp can be configured.

  The second light emitting unit 24b only needs to be a light source whose light emission color satisfies the white range on the CIE chromaticity diagram defined by the law and has an S / P ratio of 2.0 or more. It is not limited to a white LED light source having a structure in which the LED element R and the phosphor-containing layer (green phosphor G) are combined.

  For example, as shown in FIG. 4B, the second light emitting unit 24b may be a white LED light source having a structure in which a blue LED element B and a wavelength conversion member 22b (green and red phosphor GR) are combined. .

  The second light emitting unit 24b may be a white LED light source having a structure in which a red LED element, a green LED element, and a blue LED element are combined, or an ultraviolet or near ultraviolet LED element and a phosphor-containing layer (RGB phosphor). ) May be a white LED light source having a structure. Even in the white LED light source having these structures, by adjusting the concentration or the like of the wavelength conversion member 22b (for example, phosphor), the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, In addition, a light source having an S / P ratio of 2.0 or more can be configured.

  The second light emitting unit 24b is not limited to a white LED light source as long as the light emission color satisfies the white range on the CIE chromaticity diagram specified by law and the S / P ratio is 2.0 or more. .

  For example, the second light emitting unit 24b absorbs laser light from a laser light source (for example, a laser diode (blue laser diode)) and a wavelength conversion member 22b (for example, a laser light source, converts the wavelength, and emits light in a predetermined wavelength range. And a white laser light source having a structure in combination with a wavelength converting member such as a yellow phosphor that emits light. By using a laser light source as the semiconductor light emitting element 18b, it is possible to configure the second light emitting portion 24b having a small light emission area (closer to a point light source) and high brightness compared to the case where a light emitting diode is used as the semiconductor light emitting element 18b. It becomes.

  FIG. 26A and FIG. 26B are examples of the second light emitting unit 24b using a laser light source as the semiconductor light emitting element 18b.

  FIG. 26A shows a second light emitting unit having a structure in which the semiconductor light emitting element 18b (laser light source) is disposed at a position spaced from the wavelength converting member 22b, and the condenser lens 13 and the wavelength converting member 22b are disposed in front of the semiconductor light emitting element 18b. This is an example of 24b (white laser light source). In FIG. 26B, a semiconductor light emitting element 18b (laser light source) is disposed at a position spaced from the wavelength conversion member 22b, and a condensing lens 13 and a light guide 15 (for example, an optical fiber including a core and a cladding) are disposed in front of the semiconductor light emitting element 18b. ) Of the second light emitting unit 24b (white laser light source) having a structure in which the wavelength conversion member 22b is disposed on the light exit surface 15b of the light guide 15.

[Vehicle headlamp configuration example 1]
Next, a reflector-type (reflection-type) lamp unit will be described as a configuration example of a vehicle lamp unit using the white light source 10 having the above configuration.

  FIG. 23B is a cross-sectional view of the vehicle lamp unit 44L disposed on the “left side” of the front portion of the vehicle, taken along a horizontal plane including the optical axis thereof. FIG. 24B is a cross-sectional view of the vehicle lamp unit 44R disposed on the “right side” of the front portion of the vehicle, cut along a horizontal plane including the optical axis thereof.

  As shown in FIGS. 23 (b) and 24 (b), the vehicle lamp units 44L and 44R of the present embodiment are arranged on both the left and right sides of the front surface of a vehicle such as an automobile to constitute a vehicle headlamp. ing. A known aiming mechanism (not shown) is connected to the vehicle lamp units 44L and 44R so that the optical axis can be adjusted.

  The vehicular lamp unit 44L disposed on the left side of the front portion of the vehicle and the vehicular lamp unit 44R disposed on the right side of the front portion of the vehicle are substantially symmetrical and have the same configuration. For this reason, the following description will focus on the vehicle lamp unit 44L disposed on the left side of the vehicle front, and the description of the vehicle lamp unit 44R disposed on the right side of the vehicle front will be omitted.

  As shown in FIG. 23B, the vehicular lamp unit 44L is a reflector-type (reflective) lamp unit, and is a paraboloid such as a paraboloid of revolution (a paraboloid of revolution or a similar free-form surface). System reflecting surface) 46L, white light source 10 and the like.

When the reflecting surface 46L is a single reflecting surface, the first light emitting unit 24a is disposed at or near the focal point F _46L (corresponding to the focal point of the optical system of the present invention) of the reflecting surface 46L. On the other hand, when the reflecting surface 46L is a plurality of reflecting surfaces, the first light emitting unit 24a is disposed at or near the focal point of each reflecting surface.

  Here, the focal point is not only the focal point when the focal point is clear like the focal point of the rotating paraboloid, but also the focal point of the rotating paraboloid even if it has no clear focal point like the free-form surface. The point that can be regarded as the focal point is called the focal point (also referred to as the reference point (optical center) in optical design). For example, when parallel light is irradiated onto the reflecting surface 46L from the front surface of the reflecting surface 46L, the center position where light is most collected is set as a focal point (the same applies in the present embodiment).

In the second light emitting unit 24b, the light / dark boundary on one end side (left side) of the second light distribution pattern PLb is outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. It is arranged at a position spaced from the focal point F _46L (corresponding to the focal point of the optical system of the present invention) of the reflecting surface 46L so as to be positioned.

That is, the distance between the focal point _{F 46L} of the reflecting surface 46L and the center point of the first light emitting portion 24a (corresponding to a focus of the optical system of the present invention) and Dl, the focal point of the reflecting surface 46L and the center point of the second light emitting unit 24b When the distance to F _46L (corresponding to the focal point of the optical system of the present invention) is D2, there is a relationship of D1 <D2.

  In the vehicle lamp unit 44L having the above-described configuration (the same applies to the vehicle lamp unit 44R), the light emitted from the first light emitting unit 24a is reflected by the reflecting surface 46L and irradiated forward. As a result, the first light distribution pattern PLa that irradiates the central region A5L is formed on a virtual vertical screen (disposed approximately 25 m ahead from the front of the vehicle) facing the front of the vehicle (FIG. 23A). reference).

On the other hand, the light emitted from the second light emitting unit 24b is reflected forward by the reflection surface 46L and spreads forward as one side (front left side) in the horizontal direction with respect to the optical axis AX _46L of the reflection surface 46L. Is done. Why the light emitted from the second light emitting unit 24b is irradiated to the front as light spreading on one side of the horizontal direction (front left side) with respect to the optical axis AX _46L of the reflecting surface 46L, the second light emitting unit 24b There is because is disposed at a position spaced apart from the focal point _{F 46L} of the reflecting surface 46L (Dl <D2).

  Thereby, the second light distribution pattern PLb is formed on the virtual vertical screen in a state of being superimposed on the first light distribution pattern PLa.

Since the second light emitting portion 24b is disposed at a position spaced from the focal point _{F 46L} of the reflecting surface 46L (Dl <D2), dark boundary of one end side of the horizontal direction of the second light distribution pattern PLb (left) Is located outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. That is, the second light distribution pattern PLb extends to the left from the left edge (left light / dark boundary) of the first light distribution pattern PLa, and is above and below the left edge (left light / dark boundary) of the first light distribution pattern PLa. And a light distribution pattern for irradiating the peripheral area A6L (see FIG. 23A).

As described above, since the semiconductor light emitting element 18a and the semiconductor light emitting element 18b are adjacent to each other with the separation wall 20 interposed therebetween (see FIGS. 25A and 25B), the light emitting surface 10a has Causes color unevenness. For example, near the blue semiconductor light emitting elements 18a and 18b, blue is strong, and when away from the blue semiconductor light emitting elements 18a and 18b, yellow which is a light component including a complementary color of blue is strong. In addition, since the side wall of the outer frame 14 becomes a reflection surface in the vicinity of the outer frame 14, the blue light component emitted from the blue semiconductor light emitting elements 18a and 18b increases, and the blue color becomes stronger only in the vicinity of the outer frame 14, resulting in color unevenness. Cheap. However, since the color unevenness side is away from the focal point F _{46L, a} blurred light distribution pattern (light distribution pattern in which the influence of the color unevenness is improved) is obtained.

  The vehicle lamp unit 44L (same for the vehicle lamp unit 44R) is optically adjusted by a known aiming mechanism (not shown) so as to irradiate the central area A5L and the peripheral area A6L.

As described above, according to the vehicle lamp unit 44L of this embodiment (the same applies to the vehicle lamp unit 44R), the focal point F _46L of the reflecting surface _46L (corresponding to the focal point of the optical system of the present invention) and each light emitting unit Using the difference in the degree of coincidence with 24a and 24b, light from the second light emitting unit 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting unit 24a is blurred. By making the irradiation area wider than the light from the light emitting part 24a, the light-dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa formed by the light from the first light emitting part 24a The outside (the peripheral area A6L in front of the vehicle) can be irradiated with light from the second light emitting unit 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting unit 24a. (See FIG. 23 (a)). As a result, it becomes possible to speed up awareness in peripheral vision in a dark environment during night driving.

  When the central region A5 is irradiated with light emitted from a light source having the same S / P ratio as that of the second light emitting part 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting part 24a, This will give the car a feeling of glare.

  According to the vehicle lamp unit 44L of the present embodiment (the same applies to the vehicle lamp unit 44R), the first light emitting unit 24a (S / P ratio is less than 2.0) having a lower S / P ratio than the second light emitting unit 24b. Since the center area A5L is irradiated with the light emitted from the center area A5L, compared to the case where the center area A5L is irradiated with the light emitted from the light source having the same S / P ratio as the second light emitting unit 24b, the oncoming vehicle is dazzled. It is possible to suppress the feeling of glare.

  As described above, according to the vehicle lamp unit 44L of the present embodiment (the same applies to the vehicle lamp unit 44R), it is possible to suppress the oncoming vehicle from being dazzled (glare) and to be operated at night. It becomes possible to speed up the awareness of peripheral vision in the dark environment of time.

[Vehicle headlamp configuration example 2]
Next, a projector-type lamp unit will be described as a configuration example of a vehicle lamp unit using the white light source 10 having the above configuration.

  FIG. 27A is a cross-sectional view of the vehicle lamp unit 48L (or 48R) disposed on the left side (or right side) of the front portion of the vehicle, cut along a vertical plane including its optical axis.

  The vehicular lamp unit 48 of the present embodiment is disposed on both the left and right sides of the front surface of a vehicle such as an automobile to constitute a vehicular headlamp. A known aiming mechanism (not shown) is connected to the vehicle lamp unit 48 so that the optical axis can be adjusted.

  The vehicle lamp unit 48L disposed on the left side of the vehicle front portion and the vehicle lamp unit 48R disposed on the right side of the vehicle front portion have substantially the same configuration. For this reason, the following description will focus on the vehicle lamp unit 48L disposed on the left side of the vehicle front, and the description of the vehicle lamp unit 48R disposed on the right side of the vehicle front will be omitted.

  As shown in FIG. 27A, the vehicle lamp unit 48L is a projector-type lamp unit, and includes a projection lens 50, a white light source 10, a spheroid reflection surface 52, and the like.

The projection lens 50 is disposed on an optical axis AX ₄₈ that is held by a lens holder (not shown) or the like and extends in the vehicle front-rear direction.

  The projection lens 50 is, for example, a planoconvex aspherical projection lens having a convex front surface and a flat rear surface.

White light source 10, while the light emitting surface 10a faces upward, it is disposed at the rear side and the optical axis AX ₄₈ near side focal point F ₅₀ of the projection lens 50.

The first light emitting unit 24a is disposed on the first focal point F1 ₅₂ of the reflecting surface ₅₂ or in the vicinity thereof.

In the second light emitting unit 24b, the light / dark boundary on one end side (left side) of the second light distribution pattern PLb is outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. The reflecting surface 52 is disposed at a position spaced from the first focal point F _< b> 1 ₅₂ so as to be positioned.

Reflecting surface 52, a first focal point _{F1 52} is set to the first vicinity of the light emitting portion 24a of the white light source 10, the reflection of the spheroid system second focal point _{F2 52} is set at the back focal _{F 50} near the rear of the projection lens 50 A surface (spheroid surface or similar free-form surface).

  The reflecting surface 52 extends from the side of the white light source 10 (the side of the vehicle rear side in FIG. 27A) toward the projection lens 50 so that light emitted upward from the white light source 10 is incident. The white light source 10 is covered above.

As described above, since the first light emitting unit 24a is disposed substantially coincident with the first focal point F1 ₅₂ , the light from the first light emitting unit 24a reflected by the reflecting surface 52 is behind the projection lens 50. The light is condensed at a focal point F ₅₀ (corresponding to the focal point of the optical system of the present invention).

Further, since the second light emitting unit 24b is disposed at a position separated from the first focal point F1 ₅₂ , the light from the second light emitting unit 24b reflected by the reflecting surface 52 is the rear focal point F50 of the projection lens _50. The light is condensed at a position (corresponding to the condensing point of the second light emitting unit of the present invention) separated from (corresponding to the focal point of the optical system of the present invention).

In other words, the condensing point of the irradiation light from the first light emitting unit 24a (corresponding to the first condensing point of the present invention) and the rear focal point F ₅₀ of the projection lens ₅₀ (corresponding to the focal point of the optical system of the present invention). The distance is Dl, and the condensing point of the irradiation light from the second light emitting unit 24b (corresponding to the second condensing point of the present invention) and the rear focal point F ₅₀ of the projection lens ₅₀ (corresponding to the focal point of the optical system of the present invention). ), The relationship is Dl <D2.

In the vehicular lamp unit 48L having the above-described configuration (the same applies to the vehicular lamp unit 48R), the light emitted from the first light emitting unit 24a is reflected by the reflecting surface 52 and is the rear focal point F ₅₀ (this) of the projection lens 50. After being condensed at the focal point of the optical system of the invention, the light is transmitted through the projection lens 50 and irradiated forward. As a result, the first light distribution pattern PLa that irradiates the central region A5 is formed on a virtual vertical screen (disposed approximately 25 m ahead from the front of the vehicle) facing the front of the vehicle (FIG. 23A). reference).

On the other hand, the light emitted from the second light emitting unit 24b is reflected by the reflecting surface 52 and separated from the rear focal point F50 (corresponding to the focal point of the optical system of the present invention) of the projection lens ₅₀ (the first of the present invention). after condensing the corresponding) to the focal point of the second light-emitting unit, passes through the projection lens 50 and is irradiated forward as light spreading on one side of the horizontal direction (front left side) with respect to the optical axis AX ₄₈ . The reason why the light emitted from the second light emitting unit 24b is irradiated forward as light spreading on one side (front left side) in the horizontal direction with respect to the optical axis AX ₄₈ is that the second light emitting unit 24b is projected to the projection lens 50. This is because it is disposed at a position separated from the rear focal point F ₅₀ (corresponding to the focal point of the optical system of the present invention) (Dl <D2).

  Thereby, the second light distribution pattern PLb is formed on the virtual vertical screen in a state of being superimposed on the first light distribution pattern PLa.

Focus F ₅₀ of the second light emitting portion 24b is a projection lens 50 for being disposed at a position spaced from _{(corresponding} to the focus of the optical system of the present invention) (Dl <D2), the horizontal direction of the second light distribution pattern PLb The light / dark boundary on one end side (left side) is located outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. That is, the second light distribution pattern PLb extends to the left from the left edge (left light / dark boundary) of the first light distribution pattern PLa, and is above and below the left edge (left light / dark boundary) of the first light distribution pattern PLa. And a light distribution pattern for irradiating the peripheral area A6L (see FIG. 23A).

As described above, since the semiconductor light emitting element 18a and the semiconductor light emitting element 18b are adjacent to each other with the separation wall 20 interposed therebetween (see FIGS. 25A and 25B), the light emitting surface 10a has Color unevenness occurs (the blue color is strong near the semiconductor light emitting elements 18a and 18b, and the yellow color is strong when separated from the semiconductor light emitting elements 18a and 18b). However, the light distribution pattern blurred because color unevenness side away from the focal point F ₅₂ of the reflecting surface 52 _(rear focal point F ₅₀ of the projection lens _50).

  The vehicle lamp unit 48L (same for the vehicle lamp unit 48R) is optically adjusted by a known aiming mechanism (not shown) so as to irradiate the central area A5L and the peripheral area A6L.

As described above, according to the vehicle lamp unit 48L of the present embodiment (the same applies to the vehicle lamp unit 48R), the focal point F ₅₀ of the projection lens ₅₀ (corresponding to the focal point of the optical system of the present invention) and each light emitting unit Using the difference in coincidence with the light condensing points of the light from 24a, 24b, the second light emitting unit 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting unit 24a. One end side in the horizontal direction of the first light distribution pattern PLa formed by the light from the first light emitting unit 24a by blurring the light and making the irradiation area wider than the light from the first light emitting unit 24a Light from the second light emitting part 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting part 24a outside the (left side) light / dark boundary (peripheral area A6L in front of the vehicle). Irradiation is possible (see FIG. 23A). As a result, it becomes possible to speed up awareness in peripheral vision in a dark environment during night driving.

  When the central region A5 is irradiated with light emitted from a light source having the same S / P ratio as that of the second light emitting part 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting part 24a, This will give the car a feeling of glare.

  According to the vehicle lamp unit 48L of the present embodiment (the same applies to the vehicle lamp unit 48R), the first light emitting unit 24a (S / P ratio is less than 2.0) having an S / P ratio lower than that of the second light emitting unit 24b. Since the center area A5L is irradiated with the light emitted from the center area A5L, compared to the case where the center area A5L is irradiated with the light emitted from the light source having the same S / P ratio as the second light emitting unit 24b, the oncoming vehicle is dazzled. It is possible to suppress the feeling of glare.

  As described above, according to the vehicular lamp unit 48L of the present embodiment (the same applies to the vehicular lamp unit 48R), it is possible to suppress the oncoming vehicle from being dazzled (glare), and to drive at night. It becomes possible to speed up the awareness of peripheral vision in the dark environment of time.

[Configuration example 3 of vehicle headlamp]
Next, as a configuration example of a vehicle lamp unit using the white light source 10 having the above configuration, a direct projection type (direct-light type) lamp unit will be described.

  FIG. 27B is a cross-sectional view of the vehicle lamp unit 54L (or 54R) disposed on the left side (or right side) of the front portion of the vehicle, cut along a vertical plane including the optical axis thereof.

  The vehicular lamp unit 54 of the present embodiment is disposed on both the left and right sides of the front surface of a vehicle such as an automobile to constitute a vehicular headlamp. A known aiming mechanism (not shown) is connected to the vehicular lamp unit 54 so that the optical axis can be adjusted.

  The vehicle lamp unit 54L disposed on the left side of the front portion of the vehicle and the vehicle lamp unit 54R disposed on the right side of the front portion of the vehicle have substantially the same configuration. Therefore, the following description will focus on the vehicle lamp unit 54L disposed on the left side of the vehicle front, and the description of the vehicle lamp unit 54R disposed on the right side of the vehicle front will be omitted.

  As shown in FIG. 27B, the vehicle lamp unit 54L is a direct projection (direct-light) lamp unit, and includes a projection lens 56, a white light source 10, and the like.

The projection lens 56 is held on a lens holder (not shown) or the like and is disposed on an optical axis AX ₅₄ that extends in the vehicle front-rear direction.

  The projection lens 56 is, for example, a planoconvex aspherical projection lens having a convex front surface and a flat rear surface.

The white light source 10 is disposed on the optical axis AX ₅₄ with its light emitting surface 10a facing the projection lens 56.

The first light emitting unit 24a is disposed at or near the focal point F ₅₆ of the projection lens 56 (corresponding to the focal point of the optical system of the present invention).

In the second light emitting unit 24b, the light / dark boundary on one end side (left side) of the second light distribution pattern PLb is outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. The projection lens 56 is disposed so as to be positioned away from the focal point F ₅₆ (corresponding to the focal point of the optical system of the present invention).

That is, the distance between the focal point F ₅₆ of the projection lens 56 and the center point of the first light emitting portion 24a _{(corresponding} to a focus of the optical system of the present invention) and Dl, focal point of the projection lens 56 and the center point of the second light emitting unit 24b When the distance to F ₅₆ (corresponding to the focal point of the optical system of the present invention) is D2, there is a relationship of D1 <D2.

  In the vehicle lamp unit 54L having the above-described configuration (the same applies to the vehicle lamp unit 54R), the light emitted from the first light emitting unit 24a passes through the projection lens 56 and is irradiated forward. As a result, the first light distribution pattern PLa that irradiates the central region A5L is formed on a virtual vertical screen (disposed approximately 25 m ahead from the front of the vehicle) facing the front of the vehicle (FIG. 23A). reference).

On the other hand, the light emitted from the second light emitting unit 24 b passes through the projection lens 56 and is irradiated forward as light spreading on one side (front left side) in the horizontal direction with respect to the optical axis AX ₅₄ . The reason why the light emitted from the second light emitting unit 24b is irradiated forward as light spreading to one side (front left side) in the horizontal direction with respect to the optical axis AX ₅₄ is that the second light emitting unit 24b is projected to the projection lens 56. This is because it is arranged at a position away from the rear focal point F ₅₆ (corresponding to the focal point of the optical system of the present invention) (Dl <D2).

  Thereby, the second light distribution pattern PLb is formed on the virtual vertical screen in a state of being superimposed on the first light distribution pattern PLa.

The second light emitting portion 24b is disposed at a position spaced from the rear focal point F ₅₆ of the projection lens 56 _{(corresponding} to the focus of the optical system of the present invention) (Dl <D2) for the horizontal of the second light distribution pattern PLb The light / dark boundary on one end side (left side) in the direction is located outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. That is, the second light distribution pattern PLb extends to the left from the left edge (left light / dark boundary) of the first light distribution pattern PLa, and is above and below the left edge (left light / dark boundary) of the first light distribution pattern PLa. And a light distribution pattern for irradiating the peripheral area A6L (see FIG. 23A).

As described above, since the semiconductor light emitting element 18a and the semiconductor light emitting element 18b are adjacent to each other with the separation wall 20 interposed therebetween (see FIGS. 25A and 25B), the light emitting surface 10a has Color unevenness occurs (the blue color is strong near the semiconductor light emitting elements 18a and 18b, and the yellow color is strong when separated from the semiconductor light emitting elements 18a and 18b). However, the light distribution pattern blurred because color unevenness side away from the side focal point F ₅₆ of the projection lens 56.

  The vehicle lamp unit 54L (same for the vehicle lamp unit 54R) is optically adjusted by a known aiming mechanism (not shown) so as to irradiate the central area A5L and the peripheral area A6L.

As described above, according to the vehicular lamp unit 54L of the present embodiment (also the vehicular lamp unit 54R), the rear focal point F ₅₆ (corresponding to the focal point of the optical system of the present invention) of the projection lens 56 and each Using the difference in the degree of coincidence with the light emitting units 24a and 24b, the light from the second light emitting unit 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting unit 24a is blurred, By making the irradiation area wider than the light from the first light emitting part 24a, the brightness of one end side (left side) in the horizontal direction of the first light distribution pattern PLa formed by the light from the first light emitting part 24a It is possible to irradiate the outside (peripheral area A6L in front of the vehicle) with light from the second light emitting unit 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting unit 24a. (See FIG. 23A). As a result, it becomes possible to speed up awareness in peripheral vision in a dark environment during night driving.

  When the central region A5 is irradiated with light emitted from a light source having the same S / P ratio as that of the second light emitting part 24b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting part 24a, This will give the car a feeling of glare.

  According to the vehicle lamp unit 54L of the present embodiment (the same applies to the vehicle lamp unit 54R), the first light emitting unit 24a (S / P ratio is less than 2.0) having a lower S / P ratio than the second light emitting unit 24b. Since the center area A5L is irradiated with the light emitted from the center area A5L, compared to the case where the center area A5L is irradiated with the light emitted from the light source having the same S / P ratio as the second light emitting unit 24b, the oncoming vehicle is dazzled. It is possible to suppress the feeling of glare.

  As described above, according to the vehicular lamp unit 54L of the present embodiment (the same applies to the vehicular lamp unit 54R), it is possible to suppress the oncoming vehicle from being dazzled (glare) and to be operated at night. It becomes possible to speed up the awareness of peripheral vision in the dark environment of time.

[Configuration example 2 of white light source]
Next, a configuration example 2 of the white light source used for forming the light distribution patterns PL and PR (see FIG. 23A and FIG. 24A) that are quickly noticed in peripheral vision will be described.

  FIG. 28A is a front view of a white light source used to form the light distribution patterns PL and PR (see FIGS. 23A and 24A) that are quickly noticed in peripheral vision. FIG. 28B is a sectional view taken along line AA in FIG. 28A, and FIG. 28C is a sectional view taken along line BB in FIG.

  As shown in FIGS. 28A to 28C, the white light source 26 includes a first light emitting unit 42a using a semiconductor light emitting element 38a, and a second light emitting unit 42b using semiconductor light emitting elements 38b to 38e. 42e.

  The white light source 26 includes a ceramic substrate 28 (for example, a co-fired ceramic), an outer frame 30 surrounding an edge on the ceramic substrate 28, an inner frame 32 as a separation wall disposed inside the outer frame 30, the ceramic substrate 28, A rectangular annular recess 34 surrounded by the outer frame 30 and the inner frame 32, a central recess 36 surrounded by the ceramic substrate 28 and the inner frame 32, at least five semiconductor light emitting elements 38a to 38e, and the like are included.

  The semiconductor light emitting element 38 a is a light emitting diode made of, for example, a gallium nitride semiconductor, and is disposed in the central recess 36 (upper surface of the ceramic substrate 28) and is surrounded by the central recess 36.

  The remaining four semiconductor light emitting elements 38b to 38e are light emitting diodes made of, for example, a gallium nitride semiconductor, and are disposed in the rectangular annular recess 34 (on the upper surface of the ceramic substrate 28) so as to surround the semiconductor light emitting element 38a. The height of the inner frame 32 as a separation wall is higher than that of the outer frame 30 by increasing the number of cera layers from that of the outer frame 30 in order to prevent light leakage.

  The semiconductor light emitting element 38a (for example, a blue LED element) is covered with a wavelength conversion member 40a (for example, a phosphor-containing layer (yellow phosphor)) filled in the central recess 36, and the first light emitting unit 42a (white LED). Light source).

  The wavelength conversion member 40a is a mixture of light excited by light from the semiconductor light emitting element 38a (for example, yellow light) and light from the semiconductor light emitting element 38a that is transmitted through the wavelength conversion member 40a (for example, blue light). Emits white light.

  The first light emitting unit 42a adjusts the concentration of the wavelength conversion member 40a (for example, a yellow phosphor) so that the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, and the S / P The ratio is adjusted to less than 2.0 (for example, 1.5).

  The first light emitting unit 42a that irradiates the central region A5L has a lower S / P ratio (S / P ratio of 2) than the second light emitting unit 42b (S / P ratio is 2.0 or more) that irradiates the peripheral region A6L. Less than 0). The reason is that if the central area A5L is irradiated with light having the same S / P ratio as the second light emitting unit 42b that irradiates the peripheral area A6L, the oncoming vehicle is given a glare (glare), which is suppressed. Because.

  The S / P ratio of the first light emitting unit 42a is desirably 1.5 or more. The reason is that if the S / P ratio is less than 1.5, it is difficult to satisfy the white range on the CIE chromaticity diagram defined by the law.

  The first light emitting unit 42a may be a light source whose emission color satisfies the white range on the CIE chromaticity diagram specified by law and has an S / P ratio of less than 2.0. It is not limited to the white LED light source of the structure which combined the containing layer (yellow fluorescent substance).

  For example, the first light emitting unit 42a may be a white LED light source having a structure in which a blue LED element B and a phosphor-containing layer (green and red phosphor GR) are combined, as shown in FIG. 4B. .

  The first light emitting unit 42a may be a white LED light source having a structure in which a red LED element, a green LED element, and a blue LED element are combined, or an ultraviolet or near ultraviolet LED element and a phosphor-containing layer (RGB phosphor). ) May be a white LED light source having a structure. Even in the white LED light source having these structures, by adjusting the concentration or the like of the wavelength conversion member 40a (for example, phosphor), the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, And it is possible to comprise the light source whose S / P ratio is less than 2.0.

  The first light emitting unit 42a is not limited to a white LED light source as long as the light emission color satisfies the white range on the CIE chromaticity diagram stipulated by law and the S / P ratio is less than 2.0. .

  For example, the first light emitting unit 42a absorbs laser light from a laser light source (for example, a laser diode (blue laser diode)) and a wavelength conversion member 40a (for example, a laser light source, converts the wavelength, and emits light in a predetermined wavelength range. And a white laser light source having a structure in combination with a wavelength converting member such as a yellow phosphor that emits light (see FIGS. 26A and 26B). By using a laser light source as the semiconductor light emitting element 38a, it is possible to configure the first light emitting portion 42a having a small light emission area (closer to a point light source) and high brightness as compared with the case where a light emitting diode is used as the semiconductor light emitting element 38a. It becomes.

  The remaining four semiconductor light emitting elements 38b to 38e are covered with a wavelength conversion member 40b filled in the rectangular annular recess 34 to constitute second light emitting parts 42b to 42e (white LED light sources).

  For example, the semiconductor light emitting elements 38b to 38e are the blue LED element B and the red LED element R shown in FIG. 4A, and the wavelength conversion member 40b is the green phosphor G shown in FIG. The green phosphor G is excited by the blue light emitted from the blue LED element B and emits green light. When green light increases, the emission color becomes blue-green, which deviates from the white range on the CIE chromaticity diagram defined by law. Therefore, by adjusting the output by adding the red LED element R, the emission color is adjusted to be within the white range on the CIE chromaticity diagram defined by the law.

  The second light emitting units 42b to 42e adjust the concentration of the wavelength conversion member 40b (for example, a green phosphor) so that the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, and S / P ratio is adjusted to 2.0 or more (for example, 2.0).

  The second light emitting unit (for example, the second light emitting unit 42b) that irradiates the peripheral region A6L is a light source having an S / P ratio of 2.0 or more. The reason is that as the S / P ratio increases to 2.0 or higher, the perception in peripheral vision becomes faster (the reaction speed becomes shorter and the miss rate decreases) (see Experiment 1 and Experiment 2). This is based on speeding up the awareness of peripheral vision in a dark environment during night driving (reducing the reaction speed and reducing the missed rate).

  The S / P ratio of the second light emitting unit is desirably 3.0 or less. The reason is that when the S / P ratio exceeds 3.0, it is difficult to satisfy the white range on the CIE chromaticity diagram defined by the law.

  From the correlation between the S / P ratio and the missed rate, based on the knowledge that the S / P ratio is 2.5 (or 2.5 or more) and there is no difference in awareness due to age (see Experiment 1), S / P By irradiating the surrounding area with light emitted from a light source with a P ratio of 2.5 or 2.5 to 3.0, there is no difference in awareness due to age in a dark environment during night driving. An illumination lamp can be configured.

  The second light emitting units 42b to 42e may be any light source that satisfies the white range on the CIE chromaticity diagram defined by the law and that has an S / P ratio of 2.0 or more. The white LED light source having a structure in which the red LED element R and the phosphor-containing layer (green phosphor G) are combined is not limited.

  For example, as shown in FIG. 4B, the second light emitting units 42b to 42e are white LED light sources having a structure in which a blue LED element B and a phosphor-containing layer 22b (green and red phosphor GR) are combined. May be.

  The second light emitting units 42b to 42e may be white LED light sources having a structure in which a red LED element, a green LED element, and a blue LED element are combined, or an ultraviolet or near ultraviolet LED element and a phosphor-containing layer (RGB It may be a white LED light source having a structure in combination with a phosphor. Even in the white LED light source of these structures, by adjusting the concentration of the wavelength conversion member 40b (for example, phosphor), the emission color satisfies the white range on the CIE chromaticity diagram defined by the law, In addition, a light source having an S / P ratio of 2.0 or more can be configured.

  The second light emitting units 42b to 42e may be any light source that has a light emission color that satisfies the white range on the CIE chromaticity diagram defined by law and that has an S / P ratio of 2.0 or more. It is not limited.

  For example, the second light emitting units 42b to 42e are configured to absorb a laser light source (for example, a laser diode (blue laser diode)) and a wavelength conversion member 40b (for example, a laser light from the laser light source, and convert the wavelength to a predetermined wavelength range). And a white laser light source having a structure in combination with a wavelength conversion member such as a yellow phosphor that emits the light (see FIGS. 26A and 26B). By using laser light sources as the semiconductor light emitting elements 38b to 38e, the light emitting areas are smaller (closer to the point light sources) and the second light emitting parts 42b to 42e have higher luminance than when using light emitting diodes as the semiconductor light emitting elements 38b to 38e. Can be configured.

[Vehicle headlamp configuration example 4]
Next, reflector-type (reflection-type) vehicle lamp units 44L ′ and 44R ′ will be described as a configuration example of a vehicle lamp unit using the white light source 26 having the above-described configuration.

  The vehicle lamp units 44L ′ and 44R ′ of the configuration example 4 are different from the vehicle lamp unit 44L of the configuration example 1 in that the white light source 26 is used instead of the white light source 10. Other than that, it is the structure similar to the vehicle lamp units 44L and 44R of the said structural example 1. FIG. Hereinafter, the difference from the vehicle lamp unit 44L of the configuration example 1 will be mainly described, and the same components as those of the vehicle lamp unit 44L and 44R of the configuration example 1 will be denoted by the same reference numerals and the description thereof will be given. Omitted.

  FIG. 23B is a cross-sectional view of the vehicle lamp unit 44L ′ arranged on the “left side” of the front portion of the vehicle, cut along a horizontal plane including the optical axis thereof.

As shown in FIG. 23B, when the reflecting surface 46L is a single reflecting surface, the first light emitting unit 42a is located at or near the focal point F _46L of the reflecting surface _46L (corresponding to the focal point of the optical system of the present invention). Be placed. On the other hand, when the reflecting surface 46L is a plurality of reflecting surfaces, the first light emitting unit 42a is disposed at or near the focal point of each reflecting surface.

In the second light emitting unit 42b, the light / dark boundary on one end side (left side) of the second light distribution pattern PLb is outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. It is arranged at a position spaced from the focal point F _46L (corresponding to the focal point of the optical system of the present invention) of the reflecting surface 46L so as to be positioned.

That is, the distance between the focal point _{F 46L} of the reflecting surface 46L and the center point of the first light emitting portion 24a (corresponding to a focus of the optical system of the present invention) and Dl, the focal point of the reflecting surface 46L and the center point of the second light emitting unit 24b When the distance to F _46L (corresponding to the focal point of the optical system of the present invention) is D2, there is a relationship of D1 <D2.

  In the vehicle lamp unit 44L having the above-described configuration, the light emitted from the first light emitting unit 42a is reflected by the reflecting surface 46L and irradiated forward. As a result, the first light distribution pattern PLa that irradiates the central region A5L is formed on a virtual vertical screen (disposed approximately 25 m ahead from the front of the vehicle) facing the front of the vehicle (FIG. 23A). reference).

On the other hand, the light emitted from the second light emitting unit 42b is reflected forward by the reflection surface 46L and spreads forward as one side (front left side) in the horizontal direction with respect to the optical axis AX _46L of the reflection surface 46L. Is done. Why the light emitted from the second light emitting unit 42b is irradiated to the front as light spreading on one side of the horizontal direction (front left side) with respect to the optical axis AX _46L of the reflecting surface 46L, the second light emitting unit 42b There is because being arranged at a position separated from the focus F _46L of the reflecting surface 46L _{(corresponding} to the focus of the optical system of the present invention) (Dl <D2).

  Thereby, the second light distribution pattern PLb is formed on the virtual vertical screen in a state of being superimposed on the first light distribution pattern PLa.

The second light emitting portion 24b is disposed at a position spaced from the focal point _{F 46L} of the reflecting surface 46L (corresponding to the focus of the optical system of the present invention) (Dl <D2) for, in the horizontal direction of the second light distribution pattern PLb The light / dark boundary on one end side (left side) is located outside the light / dark boundary on one end side (left side) in the horizontal direction of the first light distribution pattern PLa. That is, the second light distribution pattern PLb extends to the left from the left edge (left light / dark boundary) of the first light distribution pattern PLa, and is above and below the left edge (left light / dark boundary) of the first light distribution pattern PLa. And a light distribution pattern for irradiating the peripheral area A6L (see FIG. 23A).

  The vehicular lamp unit 44L ′ is optically adjusted by a known aiming mechanism (not shown) so as to irradiate the central area A5L and the peripheral area A6L.

  FIG. 24B is a cross-sectional view of the vehicle lamp unit 44R ′ disposed on the “right side” of the front portion of the vehicle, cut along a horizontal plane including its optical axis.

As shown in FIG. 24B, when the reflecting surface 46R is a single reflecting surface, the first light emitting unit 42a is located at or near the focal point F _46R of the reflecting surface _46R (corresponding to the focal point of the optical system of the present invention). Be placed. On the other hand, when the reflecting surface 46R is a plurality of reflecting surfaces, the first light emitting unit 42a is disposed at or near the focal point of each reflecting surface.

In the second light emitting unit 42c, the light / dark boundary on one end side (right side) of the second light distribution pattern PLb is outside the light / dark boundary on one end side (right side) in the horizontal direction of the first light distribution pattern PLa. It is arranged at a position spaced from the focal point F _46R (corresponding to the focal point of the optical system of the present invention) of the reflecting surface 46R so as to be positioned.

That is, the distance between the focal point _{F 46R} of the central point and the reflective surface 46R of the first light emitting portion 42a (corresponding to a focus of the optical system of the present invention) and Dl, the focal point of the reflecting surface 46R and the central point of the second light emitting portion 42c When the distance to F _46R (corresponding to the focal point of the optical system of the present invention) is D2, there is a relationship of D1 <D2.

  In the vehicle lamp unit 44R having the above-described configuration, the light emitted from the first light emitting unit 42a is reflected by the reflecting surface 46R and irradiated forward. As a result, the first light distribution pattern PRa that irradiates the central region A5R is formed on a virtual vertical screen (disposed approximately 25 m forward from the front of the vehicle) facing the front of the vehicle (FIG. 24A). reference).

On the other hand, the light emitted from the second light emitting unit 42c is reflected forward by the reflective surface 46R and spreads forward as light that spreads to one side (front right side) in the horizontal direction with respect to the optical axis AX _46R of the reflective surface 46R. Is done. Why the light emitted from the second light emitting portion 42c is radiated forward as light spreading on one side of the horizontal direction (front right side) with respect to the optical axis AX _46R of the reflecting surface 46R, the second light emitting portion 42c This is because it is disposed at a position away from the focal point F _46R (corresponding to the focal point of the optical system of the present invention) of the reflecting surface 46R (Dl <D2).

  Thereby, the second light distribution pattern PRb is formed on the virtual vertical screen in a state of being superimposed on the first light distribution pattern PRa.

Since the second light emitting unit 42b is disposed at a position separated from the focal point F _46R (corresponding to the focal point of the optical system of the present invention) of the reflecting surface 46R (Dl <D2), the second light distribution pattern PRb in the horizontal direction is arranged. The light / dark boundary on one end side (right side) is located outside the light / dark boundary on one end side (right side) in the horizontal direction of the first light distribution pattern PRa. That is, the second light distribution pattern PRb extends rightward from the right edge (right light-dark boundary) of the first light distribution pattern PRa, and is above and below the right edge (right light-dark boundary) of the first light distribution pattern PRa. And a light distribution pattern that irradiates the peripheral area A6R (see FIG. 23B).

  The vehicular lamp unit 44R ′ is optically adjusted by a known aiming mechanism (not shown) so as to irradiate the central area A5R and the peripheral area A6R.

As described above, according to the vehicle lamp unit 44L ′ of this embodiment (the same applies to the vehicle lamp unit 44R ′), the focal point F _46L of the reflecting surface _46L (corresponding to the focal point of the optical system of the present invention) and each Using the difference in the degree of coincidence with the light emitting units 42a, 42b, etc., the light from the second light emitting unit 42b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting unit 42a is blurred. By making the irradiation area wider than the light from the first light-emitting portion 42a, the one light-emitting pattern PLa formed by the light from the first light-emitting portion 42a on the one end side (left side) in the horizontal direction. Irradiation outside the light / dark boundary (peripheral region A6L in front of the vehicle) with light from the second light emitting unit 42b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting unit 42a. This is possible (see FIG. 23A). As a result, it becomes possible to speed up awareness in peripheral vision in a dark environment during night driving.

  When the central region A5 is irradiated with light emitted from a light source having the same S / P ratio as the second light emitting part 42b (S / P ratio is 2.0 or more) having a higher S / P ratio than the first light emitting part 42a, the opposite This will give the car a feeling of glare.

  According to the vehicle lamp unit 44L ′ of the present embodiment (the same applies to the vehicle lamp unit 44R ′), the first light emitting unit 42a (S / P ratio is 2.0) having a lower S / P ratio than the second light emitting unit 42b. Since the center region A5L is irradiated with the light emitted from the light source from the lower light source), the oncoming vehicle is compared with the case where the center region A5L is irradiated with the light emitted from the light source having the same S / P ratio as the second light emitting unit 42b. It is possible to suppress the appearance of glare.

  As described above, according to the vehicular lamp unit 44L ′ (same for the vehicular lamp unit 44R ′) of the present embodiment, it is possible to suppress the oncoming vehicle from being dazzled (glare), and It becomes possible to speed up the awareness of peripheral vision in a dark environment when driving at night.

  As described above, in the reflector type (reflection type) vehicle lamp units 44L and 44R, the white light source 26 is used in place of the white light source 10, thereby configuring the reflector type (reflection type) vehicle lamp units 44L 'and 44R'. However, in the projector-type vehicle lamp units 48L and 48R and the direct projection type (direct-light type) vehicle lamp units 54L and 54R, the white light source 26 is used instead of the white light source 10. The projector-type vehicle lamp units 48L ′ and 48R ′ and the direct projection type (direct-light type) vehicle lamp units 54L ′ and 54R ′ can be configured.

  In these projector-type vehicle lamp units 48L ′, 48R ′ and direct projection type (direct-light type) vehicle lamp units 54L ′, 54R ′, it is also possible to suppress the glare from the oncoming vehicle. This is possible, and it becomes possible to speed up awareness in peripheral vision in a dark environment during night driving.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  DESCRIPTION OF SYMBOLS 10 ... White light source, 10a ... Light-emitting surface, 11 ... Condensing lens, 12 ... Ceramic substrate, 13 ... Condensing lens, 14 ... Outer frame, 15 ... Light guide, 15a ... Light-incident surface, 15b ... Light-emitting surface, 16 ... Recessed portion, 18a, 18b ... semiconductor light emitting element, 20 ... separation wall, 22a, 22b ... wavelength conversion member, 24a ... first light emitting portion, 24b ... second light emitting portion, 26 ... white light source, 28 ... ceramic substrate, 30 ... outside Frame, 32 ... inner frame, 34 ... rectangular annular recess, 36 ... central recess, 38a ... first semiconductor light emitting element, 38b-38e ... second semiconductor light emitting element, 40a, 40b ... wavelength conversion member, 42a ... first light emitting part , 42b to 42e ... second light emitting unit, 44L, 44R ... vehicle lamp unit (reflector type), 46L, 46R ... reflective surface, 48L, 48R ... vehicle lamp unit, 50 ... projection lens, 52 ... reflective surface, 4L, 54R ... vehicle lighting unit, 56 ... projection lens

Claims (7)

A white light source including a first light emitting unit using a semiconductor light emitting element and a second light emitting unit using a semiconductor light emitting element, a reflective surface and / or a lens, and irradiating light from the white light source forward In a vehicle headlamp provided with an optical system that forms a predetermined light distribution pattern on a virtual vertical screen facing the front of the vehicle,
The distance between the central point of the first light emitting unit or the first condensing point of the irradiation light from the first light emitting unit and the focal point of the optical system is D1, and the central point of the second light emitting unit or the second light emission. When the distance between the second condensing point of the irradiation light from the part and the focal point of the optical system is D2, there is a relationship of D1 <D2.
The predetermined light distribution pattern includes a first light distribution pattern formed by light from the first light emitting unit irradiated forward through the optical system, and a horizontal direction through the optical system. A second light distribution pattern formed in a state of being superimposed on the first light distribution pattern by light irradiated forward as spreading light, and at least one of the horizontal directions of the second light distribution pattern The light-dark boundary on the end side is located outside the light-dark boundary on one end side in the horizontal direction of the first light distribution pattern,
The second light emitting portion, the S / P ratio than the first light-emitting portion is rather high,
The white light source includes a ceramic substrate, an outer frame surrounding an edge on the ceramic substrate, a recess surrounded by the outer frame, and at least two semiconductor light-emitting elements made of a gallium nitride semiconductor,
The two semiconductor light emitting elements are disposed in the recess,
A separation wall is disposed between the two semiconductor light emitting elements,
One of the two semiconductor light emitting elements is covered with a phosphor-containing layer to constitute the first light emitting unit,
2. The vehicle headlamp according to claim 1, wherein the other semiconductor light emitting element of the two semiconductor light emitting elements is covered with a phosphor-containing layer to constitute the second light emitting unit . The S / P ratio of the first light emitting unit is less than 2.0,
The vehicle headlamp according to claim 1, wherein the second light emitting unit has an S / P ratio of 2.0 or more. The optical system includes a rotating paraboloidal reflecting surface whose focal point is set at or near the first light emitting unit,
The distance between the central point of the first light emitting unit and the focal point of the reflecting surface of the rotary paraboloid system, which is the focal point of the optical system, is D1, and the central point of the second light emitting unit and the focal point of the optical system. 3. The vehicle headlamp according to claim 1, wherein a relationship of D <b> 1 <D <b> 2 is established, where D <b> 2 is a distance from the focal point of the reflecting surface of the rotary paraboloidal system. The optical system includes a projection lens, and a spheroidal reflecting surface in which a first focal point is set at or near the first light emitting unit, and a second focal point is set at or near the rear focal point of the projection lens. Including
A distance between the first focal point of the irradiation light from the first light emitting unit and the rear focal point of the projection lens, which is the focal point of the optical system, is D1, and the second collection of irradiation light from the second light emitting unit. The vehicle front according to claim 1 or 2, wherein a relationship of D1 <D2 is established, where D2 is a distance between a light spot and a rear focal point of the projection lens which is a focal point of the optical system. Lighting. The optical system includes a projection lens whose rear focal point is set at or near the first light emitting unit,
The distance between the central point of the first light emitting unit and the rear focal point of the projection lens, which is the focal point of the optical system, is D1, and the distance between the central point of the second light emitting unit and the focal point of the optical system is 3. The vehicle headlamp according to claim 1, wherein a relationship of D <b> 1 <D <b> 2 is established when a distance from the rear focal point is D <b> 2. The recess is divided into two recesses by the separation wall,
The one semiconductor light emitting element is disposed in one of the two recesses,
The other semiconductor light emitting element is disposed in the other concave portion of the two concave portions ,
The vehicle headlamp according to claim 1 , wherein the one semiconductor light emitting element and the other semiconductor light emitting element are adjacent to each other with the separation wall interposed therebetween. The recess includes an inner frame as the separation wall disposed inside the outer frame, a central recess surrounded by the inner frame, and an annular recess surrounded by the inner frame and the outer frame. Is divided,
The one semiconductor light emitting element is disposed in the central recess,
The vehicular headlamp according to claim 1 , wherein the other semiconductor light emitting element is disposed in the annular recess.