Lamp unit

Abstract

To provide a multi-function lamp unit that can be made smaller without increasing the number or types of light emitting elements. [Solution] This lamp unit includes a light source section 5 that emits light, and a light guide 4 that has an incident surface 45 onto which the light emitted from the light source section 5 is incident, and an exit surface from which the incident light is guided inside and exits. The light source section 5 includes a light-emitting element 51 that emits light of a predetermined color from its light-emitting surface, and further includes wavelength conversion means 6 that changes the wavelength of the light emitted from the light-emitting element 51 into a plurality of different wavelengths. When the lamp unit is turned on, the wavelength conversion means 6 is controlled to change the color of the light incident on the incident surface 45. A multi-functional lamp unit that lights up with a plurality of colored lights can be configured using a small number of light-emitting elements.

Description

[Technical Field]

[0001] The present invention relates to a lamp unit suitable for use in vehicles such as automobiles. [Background technology]

[0002] Vehicle lighting fixtures have been provided that include lamp units using light guides to enhance the design effect of the lighting fixtures. Patent Document 1 discloses a lamp unit in which light from a light source enters one end surface of a light guide made of a light-transmitting member in the shape of a plate, and the light exits from the other end surface of the light guide. With this lamp unit, the other end surface of the light guide becomes a linear light-emitting surface, enhancing the design effect when the lamp is lit.

[0003] In a lamp unit using a light guide, a plurality of light sources with different light emission colors are provided, and by switching the light emitted by these light sources, a lamp unit that emits light of different colors can be configured. In Patent Document 1, by switching between light sources of different colors, the lamp unit functions as a clearance lamp that emits white light or a turn signal lamp that emits amber light, and is configured as a multi-function lamp unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-51950 Summary of the Invention [Problem to be solved by the invention]

[0005] In a multi-function lamp unit using such a light guide, multiple light-emitting elements with different emission colors are arranged on the light guide's incident surface, and the light emitted from each light-emitting element must be incident on the light guide under equivalent conditions. Therefore, an increase in the number and types of light-emitting elements is unavoidable, and the light guide's incident surface must be designed with a unique shape or area to accommodate the increased number of light-emitting elements. A uniquely shaped incident surface makes it difficult to manufacture the light guide and to properly guide the light from the light-emitting elements into the light guide. Furthermore, increasing the area of ​​the light guide's incident surface results in an increase in the size of the light guide or lamp unit.

[0006] An object of the present invention is to provide a multi-function lamp unit that can be configured compactly without increasing the number and types of light sources such as light-emitting elements. [Means for solving the problem]

[0007] The lamp unit of the present invention is a lamp unit comprising a light source section that emits light, and a light guide that has an incident surface onto which the light emitted from the light source section is incident and an exit surface from which the incident light is guided inside and emitted, the light source section comprising a light-emitting element that emits light of a predetermined color from its light-emitting surface, and further comprising wavelength conversion means that changes the wavelength of the light emitted from the light-emitting element into a plurality of different wavelengths, and when the lamp unit is turned on, the wavelength conversion means is controlled to change the color of the light incident on the incident surface.

[0008] In the present invention, the wavelength conversion means includes a plurality of phosphor layers that emit fluorescence of different wavelengths in response to light emitted from the light-emitting element, and is controlled so that the light emitted from the light-emitting element is incident on one of the phosphor layers and the light emitted from the phosphor layer is incident on the incident surface. For example, the wavelength conversion means is moved and controlled by an actuator so that the light emitted from the light-emitting element is selectively incident on the plurality of phosphor layers.

[0009] In the present invention, preferably, the wavelength conversion means is configured such that a plurality of phosphor layers are formed as a single plate-shaped phosphor plate, and the actuator moves the phosphor plate in the plate surface direction to control the movement so that one of the plurality of phosphor layers is positioned opposite the light-emitting surface of the light-emitting element. In this case, the phosphor plate includes a frame having a plurality of window frame portions, and the phosphor layers are formed inside the plurality of window frame portions. Also, the inner edge surface of the window frame portion is inclined so that the window frame internal dimension decreases from the light-emitting element side toward the light-guiding body side. Alternatively, a lens portion that converges light is disposed on the light-emitting surface of the light-emitting element, the light-emitting element side of the phosphor layer, or the light-guiding body side of the phosphor layer. [Effects of the Invention]

[0010] According to the present invention, the wavelength of light emitted from a light-emitting element that emits light of a predetermined color can be changed into a plurality of different wavelengths by the wavelength conversion means, and the wavelength conversion means can be controlled when the lamp unit is turned on to change the color of light incident on the incident surface of the light guide. This makes it possible to reduce the number and types of light-emitting elements in a multi-function lamp unit that uses a light guide to light up with different color lights, thereby enabling the construction of a compact lamp unit with fewer parts. Obtained. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an external perspective view of an automobile equipped with a front lamp including a lamp unit according to the present invention. [Figure 2] FIG. [Figure 3] Horizontal cross section of the front lamp. [Figure 4] FIG. [Figure 5] (a) is a horizontal cross-sectional view of the light source unit, and (b) is a schematic side view of the light source unit as seen from the incident surface side. [Figure 6] FIG. 3 is an enlarged cross-sectional view of a part of a light source unit and a wavelength conversion unit. [Figure 7] FIG. 10 is an enlarged cross-sectional view of a part of a light source unit and a wavelength conversion unit of Modification 1. [Figure 8]FIG. 10 is an enlarged cross-sectional view of a part of a light source unit and a wavelength conversion unit of Modification 2. [Figure 9] FIG. 11 is an enlarged cross-sectional view of a part of a light source unit and a wavelength conversion unit of Modification 3. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a front view of an embodiment in which a lamp unit of the present invention is applied to a front lamp FL of an automobile CAR. The automobile CAR is equipped with a left front lamp L-FL and a right front lamp R-FL. Fig. 1 shows an enlarged view of the left front lamp L-FL with a portion cut away, but since the right front lamp R-FL has a symmetrical configuration, the following description of the front lamp FL will be limited to the left front lamp L-FL.

[0013] The front lamp FL has a lamp housing 100 disposed at the front of the body of the automobile CAR, and a head lamp unit 1 and an auxiliary lamp unit 2 are disposed within this lamp housing 100. The lamp housing 100 is composed of a lamp body 101 with an opening facing the side from the front of the automobile, and a colorless, transparent, and translucent cover 102 attached to this opening. Note that, hereinafter, the up-down and left-right directions are directions based on Figure 1, and the front-to-rear direction is defined as the direction of the front lamp FL facing forward of the automobile CAR.

[0014] The headlamp unit 1 is composed of three lamp units 11-13 arranged in the left-right direction in the lower region of the lamp housing 100, with the two outer lamp units 11, 12 in the vehicle width direction configured as low beam lamp units and the inner lamp unit 13 in the vehicle width direction configured as a high beam lamp unit. These low beam lamp units 11, 12 and high beam lamp unit 13 are configured as projector-type lamp units equipped with, for example, a light source, a projection lens, a reflector, etc., and are configured to irradiate light in a required light distribution pattern toward the front of the automobile CAR. This headlamp unit 1 is not particularly relevant to the present invention, so a detailed description thereof will be omitted.

[0015] The auxiliary lamp unit 2 is disposed within the lamp housing 100 across the upper region of the headlamp unit 1, and is configured as a multi-function lamp unit that functions as a clearance lamp or daytime running lamp that lights up with white light, or as a turn signal lamp that flashes with amber light. This auxiliary lamp unit 2 (hereinafter referred to as the multi-function lamp unit 2) is a lamp unit that has a light guide, and details of which will be described later.

[0016] An extension 3 that also functions as a pseudo-reflector to enhance the design effect is disposed within the lamp housing 100, and the headlamp unit 1 is disposed facing an opening provided in the extension 3. The multifunction lamp unit 2 is disposed in the upper region on the front side of the extension 3, and both ends in the length direction, i.e., the ends facing outward and inward in the vehicle width direction, are covered and hidden by the extension 3 as will be described later.

[0017] FIG. 2 is a schematic exploded perspective view of the main parts of the front lamp FL, and FIG. 3 is a horizontal cross-sectional view thereof. As described above, the headlamp unit 1 and the multifunction lamp unit 2 are housed within the housing 100 together with the extension 3. The multifunction lamp unit 2 includes a narrow, plate-like light guide 4 that extends linearly (in a line) in the left-right direction along the upper side of the headlamp unit 1. The light guide 4 is disposed along the front surface of the extension 3, and portions of both ends 41, 42 in the vehicle width direction extend to the rear side of the extension 3 through openings 31, 32 provided in the extension 3. The light guide 4 is fixed to the lamp body 101 by support brackets 43, 44 that are integral with both ends 41, 42. These ends 41, 42 and the support brackets 43, 44 are covered by the extension 3 and are not exposed from the outside through the translucent cover 102 of the front lamp FL.

[0018] The light guide 4 is formed in a rod-like shape with a predetermined cross-sectional shape. Of its two end portions 41, 42, the end portion 41 facing outward in the vehicle width direction extends to the rear side of the extension 3 as described above. The end surface 45 of the end portion 41 of the light guide 4 is formed as a flat surface with a required area, and this end surface 45 is configured as a light incident surface into which light from the light source unit 5, described below, is incident. Although not shown, of the front and rear side surfaces of the light guide 4 along the longitudinal direction, the rear side surface facing the extension 4 has minute reflective steps with a required cross-sectional shape, such as a hemispherical or pyramidal shape, formed in a required pattern arrangement. These minute reflective steps configure the rear side surface as a light reflecting surface that internally reflects light. In addition, the front side surface facing the front side is a flat surface or has refracting steps formed to diverge or diffuse light. This front side surface is configured as a light emitting surface that emits light reflected by the light reflecting surface from the light guide 4, i.e., as the light emitting surface of the multifunction lamp unit 2.

[0019] 2 and 3, the light source unit 5 is supported by the lamp body 101 on the rear side of the extension 3 so as to face one end 41 of the light guide 4. That is, the light source unit 5 is attached to a mounting hole 103 provided in the lamp body 101 at a position on the rear side of the extension 3 so as to face an end face 45 of the one end 41 that is configured as the light incident surface of the light guide 4.

[0020] 4, the light source unit 5 includes a heat sink 50 supported by the lamp body 101, and a light source substrate 52 having LEDs (light emitting diodes) 51 mounted thereon as a light source is attached to the heat sink 50. A plurality of LEDs 51 (three in this example) are surface-mounted on the light source substrate 52 and aligned vertically at a required interval, with the light-emitting surface of each LED 51 facing the light incident surface 45 of the light guide 4. The three LEDs 51 are configured to emit blue light, and are configured to emit the emitted light from their light-emitting surfaces toward the light incident surface 45.

[0021] Furthermore, a wavelength conversion unit 6 is attached to the light source unit 5, which converts the wavelength of light emitted from each LED 51 and emits the converted light onto the light incident surface 45. The wavelength conversion unit 6 includes a phosphor plate 61 having a phosphor layer that converts the wavelength of light, and an actuator 62 that moves the phosphor plate 61 back and forth in the directions of the double-headed arrows in Figure 4 to change its position. That is, by driving the actuator 62 to move the phosphor plate 61 between two positions, the light emitted from each LED 51 is converted into light of a different wavelength by the wavelength conversion unit 6 and is incident on the light incident surface 45.

[0022] The phosphor plate 61 is formed of a frame having two window frame portions 63, 64 in a horizontal direction perpendicular to the vertical direction in which the three LEDs 51 are arranged. A white phosphor layer 6w is formed in one window frame portion 63, and an amber phosphor layer 6u is formed in the other window frame portion 64. That is, the surrounding side surfaces of the white phosphor layer 6w and the amber phosphor layer 6u are covered by the window frame portions 63, 64. The white phosphor layer 6w emits yellow fluorescence when blue light from the LEDs 51 is incident thereon, and these colored lights are mixed to produce white light. The amber phosphor layer 6u emits near-red fluorescence when blue light from the LEDs 51 is incident thereon, and these colored lights are mixed to produce amber light. The white phosphor layer 6w and the amber phosphor layer 6u are made of inorganic sintered bodies obtained by sintering phosphor powders, for example. The white phosphor layer 6w uses YAG, and the amber phosphor layer 6u uses SiAlON.

[0023] 5(a) is a horizontal cross-sectional view of the light source unit 5, and FIG. 5(b) is a schematic side view of the light source unit as seen from the light incidence surface 45 side. The phosphor plate 61 is supported by an actuator 62 in a position between the light source substrate 52 and the light guide 4, that is, in a position between the light-emitting surfaces of the three LEDs 51 and the light incidence surface 45 of the light guide 4. The actuator 62 is configured as a solenoid, and includes a frame 65 incorporating a fixed iron core comprising a solenoid coil, and a movable iron core, i.e., a plunger 66, which moves back and forth between two positions by controlling the supply of current to the solenoid coil. The frame 65 is attached to the heat sink 50, and the phosphor plate 61 is attached to the plunger 66.

[0024] The plunger 66 is moved in its axial direction, that is, in the horizontal direction perpendicular to the vertical direction in which the three LEDs 51 mounted on the light source substrate 52 are arranged. When the plunger 66 is moved, the phosphor plate 61 is moved integrally therewith, and the positions of the white phosphor layer 6w and the amber phosphor layer 6u of the phosphor plate 61 relative to the LEDs 51 are switched. Here, when the plunger 66 is in the retracted position, the white phosphor layer 6w is located in front of the light-emitting surfaces of the three LEDs 51. When the plunger 66 is in the advanced position, the amber phosphor layer 6u is located in front of the light-emitting surfaces of the three LEDs 51.

[0025] Therefore, in the light source unit 5, by supplying power to the three LEDs 51 via the light source substrate 52, each LED 51 emits blue light from its light-emitting surface. Furthermore, by driving the solenoid 62 to move the plunger 66 back and forth, either the white phosphor layer 6w or the amber phosphor layer 6u faces the LED 51, as shown by the arrows in FIGS. 5(a) and 5(b). Therefore, the blue light emitted from the LED 51 passes through either the white phosphor layer 6w or the amber phosphor layer 6u of the phosphor plate 61, where it is wavelength-converted to white light or amber light. This wavelength-converted white light or amber light is incident on the light incident surface 45 of the light guide 4.

[0026] According to the multifunction lamp unit 2 configured as described above, when the unit is turned on as a clearance lamp or a daytime running lamp, the LEDs 51 are made to emit light and the solenoid 62 of the wavelength conversion unit 6 is simultaneously driven to control the plunger 66 to the retracted position. As a result, the white phosphor layer 6w of the phosphor plate 61 is positioned opposite the light-emitting surface of the LEDs 51, and the blue light emitted from the emitted LEDs 51 is transmitted through the white phosphor layer 6w, where it is wavelength-converted to white light, and then enters the light incident surface 45 of the light guide 4.

[0027] The white light incident on the light guide 4 from the light incident surface 45 is guided longitudinally (left and right) inside the light guide 4, is internally reflected by minute reflective steps on the light reflecting surface (rear surface), and is emitted from the light emitting surface (front surface) facing the front of the lamp. Therefore, the multifunction lamp unit 2 emits white light and functions as a clearance lamp or daytime running lamp.

[0028] When the multifunction lamp unit 2 functions as a turn signal lamp, the LED 51 is caused to flash and the solenoid 62 is simultaneously driven to control the plunger 66 to the advanced position. As a result, the amber phosphor layer 6u of the phosphor plate 61 is positioned opposite the light emitting surface of the LED 51, and the blue light emitted from the emitted LED 51 is transmitted through the amber phosphor layer 6u, where it is wavelength converted into amber light, which is incident on the light incident surface 45 of the light guide 4.

[0029] The amber light incident on the light guide 4 from the light incident surface 45 is internally reflected by the light reflecting surface (rear surface) while being guided longitudinally inside the light guide 4, and is emitted from the light emitting surface (front surface), just like white light. Therefore, the multifunction lamp unit 2 functions as a turn signal lamp that flashes amber light.

[0030] In this embodiment, three LEDs 51 are provided to light the multifunction lamp unit 2 at the required luminous intensity (brightness) when it is turned on, but the number of LEDs 51 can be changed appropriately depending on the luminous intensity required for the multifunction lamp unit 2. For example, it may be one LED. Furthermore, the LED 51 is not limited to an individual chip-type LED, but may be an integrated LED in which multiple LEDs are integrally formed.

[0031] Furthermore, the white phosphor layer 6w and the amber phosphor layer 6u of the phosphor plate 61 may be formed as sintered bodies as in the embodiment, or may be formed by dispersing a large number of phosphor particles in a colorless resin material.

[0032] In this way, even when the same LED 51 is used as a light source, the multifunction lamp unit 2 can function as both a lamp unit that lights up with white light and a lamp unit that lights up (flashes) with different amber colors. Therefore, the multifunction lamp unit does not need to include multiple LEDs that emit different colors of light corresponding to the number of functions (types of functions), preventing an increase in the number of LEDs. This reduces the number of components constituting the light source unit, i.e., the number of LEDs. Furthermore, the configuration of the light source unit, particularly the light source board on which the LEDs are mounted, can be made smaller than when LEDs that emit different colors of light corresponding to the number of functions are included. Furthermore, the area of ​​the light incident surface of the light guide, onto which light emitted from the LEDs is incident, does not need to increase in accordance with the number of LEDs, which is advantageous for miniaturizing the light guide.

[0033] Furthermore, in the phosphor plate 61 of this embodiment, the white phosphor layer 6w and the amber phosphor layer 6u are arranged in a horizontal direction perpendicular to the vertical direction of the three arranged LEDs 51. Therefore, when switching between the phosphor layers 6w and 6u for the LEDs 51, the phosphor plate 61 can be moved in the horizontal direction of the LEDs 51 by the solenoid 62. This makes it possible to reduce the size of the solenoid 62 for moving the phosphor plate 61. This also applies when an actuator with a configuration other than a solenoid is used, making it possible to reduce the size of the light source unit or multifunction lamp unit.

[0034] 6, which shows an enlarged view of a portion of the light source unit 5 and the wavelength conversion unit 6, the inner edge surfaces of the window frame portions 63, 64 constituting the white phosphor layer 6w and the amber phosphor layer 6u of the phosphor plate 61 may be configured to be inclined in the plate thickness direction of the phosphor plate 61. That is, in each of the window frame portions 63, 64, the inner dimension on the LED 51 side is larger than the inner dimension on the light guide 4 side.

[0035] With this configuration, light incident on the peripheral region of the phosphor layer 6w (here, a white phosphor layer) from the LED 51 is reflected by the inner edge surface of the window frame 63, which is inclined in the plate thickness direction. Because the inner edge surface is inclined so that the inner dimension is smaller toward the light guide 4 side than toward the LED 51 side, the light reflected by the inner edge surface is reflected toward the center of the phosphor layer 6w. This converges the light emitted from the LED 51 and transmitted through the phosphor layer 6w, reducing the amount of light that deviates beyond the incident surface 45 of the light guide 4 and increasing the amount of light that enters the incident surface 45. This improves the utilization efficiency of the light emitted from the LED 51, i.e., the proportion of the light emitted from the LED 51 that is used to illuminate the multifunction lamp unit 2. The same applies to the other window frame 64.

[0036] As described above, there are modified examples 1 to 3 of the configuration of the light source unit 5 and the wavelength conversion unit 6 for increasing the light utilization efficiency of the LED 51. FIG. 7 is a schematic diagram of modified example 1 of the light source unit 5 and the wavelength conversion unit 6. Modified example 1 is an example in which the light source unit 5 is modified, and is configured such that at least the light-emitting surface of the LED 51 is covered with a light-transmitting member such as a transparent resin, in other words, a light-transmitting member 71 having a required optical refractive index. This light-transmitting member is configured as a spherical or aspherical lens unit with a required radius of curvature relative to the light-emitting surface of the LED 51. It is preferable that this lens unit 71 is formed so that its focal position is located near the light-emitting surface of the LED 51.

[0037] According to the first modification, blue light emitted from the light-emitting surface of the LED 51 toward a required angular range is converged by the lens portion 71 to form a nearly parallel beam of light which is incident on the phosphor layer 6w of the phosphor plate 61, undergoes wavelength conversion, and is incident on the incident surface 45 of the light guide 4. Therefore, most of the light emitted from the LED 51 can be wavelength-converted in the phosphor layer 6w, and most of the wavelength-converted light can be made to enter the light guide 4, improving the light utilization efficiency and allowing the lamp unit to function as a bright lighting unit.

[0038] FIG. 8 is a schematic diagram of a second modification of the light source unit 5 and the wavelength conversion unit 6. The second modification is a modification of the wavelength conversion unit 6, and is configured such that a lens unit 72 is formed on the surface of the phosphor plate 61, in this case, the surface facing the incident surface 45 of the light guide 4, using a light-transmitting member having a required optical refractive index, such as a transparent resin. Similar to the first modification, the lens unit 72 is configured as a spherical or aspherical lens unit with a required radius of curvature. Although not shown in FIG. 8, the lens unit 72 is formed on the surface of each of the two phosphor layers 6w, 6u of the phosphor plate, and is positioned so that the lens unit 72 faces the LED 51 when the phosphor layers 6w, 6u are positioned facing the LED 51 by the solenoid 62.

[0039] According to the second modification, when the phosphor layers 6w, 6u of the phosphor plate 61 are positioned facing the LEDs 51, the lens portions 72 of the phosphor layers 6w, 6u are positioned facing the LEDs 51, respectively. Therefore, blue light emitted from the light-emitting surface of the LEDs 51 toward a required angular range is transmitted through the phosphor layers 6w, 6u to be converted into white light or amber light, and then transmitted through the lens portions 72 to be incident on the incident surface 45 of the light guide 4. Therefore, the light emitted from the LEDs 51 and wavelength-converted by the phosphor layers 6w, 6u is converged by the lens portions 72 and incident on the incident surface 45. This allows most of the wavelength-converted light emitted from the LEDs 45 to be incident on the light guide 4, improving light utilization efficiency and enabling the lamp unit to provide bright lighting.

[0040] 9 is a schematic configuration diagram of a third modification of the light source unit 5 and the wavelength conversion unit 6. Similar to the second modification, the third modification is a modification of the wavelength conversion unit 6, and here, a lens unit 73 is formed on the back surface of the phosphor plate 61, i.e., the surface facing the LED 51. In the third modification, similar to the second modification, although not shown, the lens unit 73 is formed on each of the two phosphor layers 6w, 6u of the phosphor plate 61, and when the phosphor layers 6w, 6u are positioned to face the LED 51 by the solenoid 62, the lens unit 73 is also formed in a position facing the LED 51.

[0041] According to the third modification, the light emitted from the LED 51 is converged by the lens portion 73 and incident on the phosphor layers 6w, 6u, and the light that has undergone wavelength conversion in the phosphor layers 6w, 6u is incident on the incident surface 45 of the light guide 4. The lens portion 73 in the third modification has the same function as the lens portion 71 in the first modification. This allows most of the light emitted from the LED 51 to be incident on the light guide 4, improving the light utilization efficiency and enabling the lamp unit to function as a bright lighting unit.

[0042] In the above embodiments, the actuator is configured as a solenoid, but as long as it is possible to move the phosphor plate in the plate surface direction and change the positions of the multiple phosphor layers, the actuator may be configured in other ways, such as an electrostatic actuator or a fluid actuator.

[0043] In addition, although the embodiment is configured as a multi-function lamp unit that lights up in white and amber, it may also be configured as a multi-function lamp unit that lights up in colors other than these colors. Furthermore, a phosphor plate may be provided with phosphor layers that convert light into three or more different colors, and these phosphor layers may be configured to be switched between three levels by an actuator. In this case, it is configured as a multi-function lamp unit that lights up in three different colors. [Explanation of symbols]

[0044] 1 Headlamp unit 2 Auxiliary lamp unit (multi-function lamp unit) 3 Extensions 4 Light guide 5 Light source section 6 Wavelength conversion section 6w white phosphor layer 6u amber phosphor layer, 45 Incidence plane 51 LED 52 Light source board 61 Phosphor plate 62 Solenoid (actuator) 63,64 Window frame 66 Plunger 71, 72, 73 Lens section

Claims

1. A lamp unit comprising a light source section that emits light, and a light guide having an incident surface onto which the light emitted from the light source section is incident and an exit surface from which the incident light is guided inside and emitted, wherein the light source section comprises a light-emitting element that emits light of a predetermined color from its light-emitting surface, and further comprises wavelength conversion means that changes the wavelength of the light emitted from the light-emitting element into a plurality of different wavelengths, and when the lamp unit is turned on, the wavelength conversion means is controlled to change the color of the light incident on the incident surface.

2. The lamp unit described in claim 1, wherein the wavelength conversion means comprises a plurality of phosphor layers that each emit fluorescence of a different wavelength in response to the light emitted from the light-emitting element, and is controlled so that the light emitted from the light-emitting element is incident on one of the phosphor layers and the light emitted from the phosphor layer is incident on the incident surface.

3. 2. The lamp unit according to claim 1, wherein the wavelength conversion means is controlled by an actuator so that the light emitted from the light emitting element is selectively incident on the plurality of phosphor layers.

4. The lamp unit described in claim 1, wherein the wavelength conversion means is formed as a phosphor plate in the form of a single plate-like phosphor layer, and the actuator moves the phosphor plate in the direction of the plate surface to control the movement so that one of the plurality of phosphor layers is positioned opposite the light-emitting surface of the light-emitting element.

5. The lamp unit according to claim 4, wherein the phosphor plate comprises a frame body having a plurality of window frame portions, the phosphor layer is formed inside the plurality of window frame portions, and the frame body covers the sides of the phosphor layer.

6. 6. The lamp unit according to claim 5, wherein an inner edge surface of the window frame is inclined so that an inner dimension of the window frame decreases from the light emitting element side toward the light guide side.

7. 5. The lamp unit according to claim 4, wherein a lens portion for converging emitted light is disposed on a light emitting surface of said light emitting element.

8. 5. The lamp unit according to claim 4, wherein a lens portion for converging light incident on or emitted from said phosphor layer is disposed on said light emitting element side or said light guide side of said phosphor layer.

9. 5. The lamp unit according to claim 4, wherein the plurality of phosphor layers include a phosphor layer that converts light emitted from the light emitting element into at least white light and chromatic light.

10. 10. The lamp unit according to claim 1, which is configured as a multi-function lamp unit that is mounted on a vehicle and lights up with a plurality of different color lights.

Images