JP2008258038A - Lighting fixture for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a field-emission lamp type lighting fixture for a vehicle capable of acquiring a sufficient amount of light by making effective use of the emitted light from phosphor in spite of a compact size. <P>SOLUTION: In the field-emission lamp type lighting fixture 10, which emits light by making a phosphor material of a phosphor 17 excite by an electron discharged from a negative electrode 16 to a positive electrode 14, having the positive electrode 14 and negative electrode 16 arranged with each other and forming an electric field, and the phosphor 17 arranged in the electric field and made of the phosphor material, reflectors 18a and 18b are arranged at a rear side of the phosphor 17. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicular lamp, and more particularly to a field emission lamp type vehicular lamp suitable as a vehicular marker lamp, a vehicular headlamp, or the like.

  Recently, as a next-generation light source, a field emission lamp (FEL) has been proposed in which electrons emitted from an electron source collide with a fluorescent material of a phosphor and the fluorescent material is excited to emit light. A vehicle lamp as a light source has also been proposed (see, for example, Patent Document 1).

  FIG. 6 shows the structure of a field emission lamp type vehicle lamp described in Patent Document 1. As shown in FIG. A vehicle lamp 1 shown in FIG. 6 includes an anode (Anode) 4, a lossless gate electrode 5, and a space 3 formed inside a vacuum vessel 2 that has been evacuated and is in a reduced pressure state. The cathode (cathode) 6 is spaced apart. A phosphor 7 made of a fluorescent material is disposed on the surface of the anode 4 (the surface facing the cathode 6). That is, the anode 4, the gate electrode 5, the cathode 6, and the phosphor 7 are hermetically housed in the space 3 of the vacuum vessel 2 that has been decompressed.

  The cathode 6 is disposed on the rear surface of the vacuum vessel 2. The gate electrode 5 is an electrode that is disposed between the anode 4 and the cathode 6 and forms an electric field for extracting electrons between the cathode 6. A voltage is applied between the gate electrode 5 and the cathode 6 by a power source (not shown) provided outside the vacuum vessel 2, and an electric field is formed between the gate electrode 5 and the cathode 6 by this voltage. As a result, electrons e − are extracted from the cathode 6, and the electrons e − are guided to the gate electrode 5 while being accelerated.

  The anode 4 is an electrode that forms an electric field for accelerating electrons that are further accelerated from the cathode 6, and a voltage is applied between the anode 4 and the cathode 6 by the power source. When a voltage is applied between the anode 4 and the cathode 6, an electron e − drawn out from the cathode 6 and passing through the gate electrode 5 by the electric field formed between the anode 4 and the cathode 6 further flows into the anode. It will be guided while accelerating towards 4.

  The fluorescent material constituting the phosphor 7 is excited and transitions to an excited state when receiving energy of a predetermined amount or more. When the fluorescent material in the excited state returns to the ground state, the excited state and the ground state are changed. Light is emitted by emitting the difference energy as light.

  The light emitted from the phosphor 7 is radiated over approximately 360 degrees in the same direction regardless of the incident direction of electrons, and only the light traveling in the light emitting direction (front side) is light transmissive such as glass. The structure is such that it passes through the member 8 and is emitted to the outside.

Such a field emission lamp type vehicular lamp does not generate heat, has a simple optical system, can be thinned, and is less expensive than a vehicular lamp using a conventional bulb or the like. Has advantageous advantages.
JP 2006-324152 A

  As described above, the structure of the conventional vehicle lamp has a structure in which only light transmitted through the light transmissive member 8 in the emission direction out of light emitted from the light emitter 7 is radiated to the outside. . For this reason, a part of the light radiated to the side opposite to the light transmissive member 8 is absorbed by the vacuum vessel 2 and disappears, so that the light loss is large. Therefore, in order to obtain the amount of light determined by the regulations, it is necessary to make the vehicle lamp larger to compensate for the light loss, and there is a problem that the vehicle lamp becomes larger.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to effectively use light emitted from a phosphor to obtain an electric field that can provide a sufficient amount of light even if it is small. Disclosed is a discharge lamp type vehicular lamp.

  A vehicular lamp according to the present invention includes an anode and a cathode that are spaced apart from each other to form an electric field, and a phosphor made of a fluorescent material that is disposed in the electric field, and is emitted from the cathode toward the anode. The field emission lamp type vehicle lamp emits light by exciting the fluorescent material of the phosphor by the electrons, and is characterized in that a reflector is provided on the back side of the phosphor.

  According to this configuration, the light emitted from the fluorescent material toward the back side of the phosphor can be effectively utilized by reflecting the light in the light emitting direction (front side) by the reflector. In addition, the light emission range can be expanded.

  The said structure WHEREIN: The structure which arrange | positions several condensing lenses facing the said fluorescent substance is employable.

  According to this configuration, the light emitted from the phosphor can be condensed by the plurality of condensing lenses and effectively used.

  The said structure WHEREIN: The structure which provided the projection lens which has a focus in the approximate center vicinity of said several condensing lens is employable.

  According to this configuration, a light distribution pattern suitable for a vehicle lamp can be easily obtained by providing the projection lens.

  According to the present invention, the light emitted from the fluorescent material toward the back side of the phosphor that has been conventionally lost is reflected in the emission direction (front side) by the reflector and emitted from the beginning toward the emission direction. Therefore, a sufficient amount of light can be obtained and a miniaturized vehicle lamp can be realized. In addition, it is possible to increase the range of light emission and the visibility.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings. 1 and 2 show a vehicular lamp shown as an embodiment of the present invention. FIG. 1 is an external perspective view thereof, and FIG. 2 is a cross-sectional view taken along line AA of FIG. In the following description, the right and left direction right side of FIG. 2 is assumed to be the front, the left side is the rear side, the up and down direction is the top and bottom, and the direction perpendicular to the paper surface is the left and right.

  1 and 2, a vehicular lamp 10 is a field emission lamp type lamp. The front opening is sealed with a light-transmitting member 11 such as glass, and is evacuated in advance to be in a reduced pressure state. A vacuum vessel 12. In the space 13 formed inside the vacuum vessel 12, an anode 14, a lossless gate electrode 15, a cathode 16, a phosphor 17 made of a fluorescent material, and a pair of upper and lower reflectors 18a and 18b are provided. Has been placed. That is, the anode 14, the gate electrode 15, the cathode 16, the phosphor 17, and a pair of upper and lower reflectors 18 a and 18 b are hermetically housed in the decompressed space 13 of the vacuum vessel 12.

  The cathode 16 is disposed on the rear surface of the vacuum vessel 12. The gate electrode 15 is an electrode that is disposed between the anode 14 and the cathode 16 and forms an electric field for extracting electrons between the anode 16 and the cathode 16. A voltage is applied between the gate electrode 15 and the cathode 16 by a power source (not shown) provided outside the vacuum vessel 12, and an electric field is formed between the gate electrode 15 and the cathode 16 by this voltage. Then, the electrons e− are extracted from the cathode 16 and are guided while being accelerated to the gate electrode 15 side. The gate electrode 15 has a fine mesh structure, for example, and can pass electrons e − in the thickness direction of the gate electrode 15, that is, in the direction from the cathode 16 to the anode 14.

  The anode 14 is an electrode for forming an electric field for electron acceleration that further accelerates electrons extracted from the cathode 16, and a voltage is applied between the anode 14 and the cathode 16 by the power source. When a voltage is applied between the anode 14 and the cathode 16, an electron e − that is drawn from the cathode 16 and passes through the gate electrode 15 by the electric field formed between the anode 14 and the cathode 16 further flows into the anode. It will be guided while accelerating towards 14.

  The fluorescent material constituting the phosphor 17 is excited and transitions to an excited state when receiving energy of a predetermined amount or more, and when the fluorescent material in the excited state returns to the ground state, the excited state and the ground state are changed. Light is emitted by emitting the difference energy as light.

  The pair of upper and lower reflectors 18a and 18b are vertically spaced apart from each other between the phosphor 17 and the gate electrode 15 and extend in the left-right direction in a parallel state so as to surround the back surface of the phosphor 17. Arranged and provided. The pair of reflectors 18 a and 18 b emit light from the phosphor 17, reflects light traveling backward opposite to the light emitting direction to the front which is the light emitting direction, and passes through the light transmitting member 11 in the light emitting direction ( The surface facing the phosphor 17 has a concave curved surface (parabolic shape), and the surface is mirror-finished such as aluminum vapor deposition or silver paint.

  On the other hand, outside the vacuum vessel 12, a lens 19 is attached to the front surface of the vacuum vessel 12 so as to cover the entire front surface of the light transmissive member 11. A plurality of condensing lens portions 19a, 19a,. The condensing lens portions 19a, 19a,... Refract and condense the light transmitted through the light transmitting member 11 and emit the light in the light emitting direction (forward).

  Next, the operation of the vehicular lamp 10 thus configured will be described. When a voltage is applied between the anode 14 and the cathode 16 and between the cathode 16 and the gate electrode 15, electrons e − are extracted from the cathode 16, and this is accelerated by the gate electrode 15 and collides with the fluorescent material of the phosphor 17. Then, the fluorescent material is changed to the excited state, and when the fluorescent material in the excited state returns to the ground state, light is emitted by emitting the energy of the difference between the excited state and the ground state as light.

  The light emitted from the phosphor 17 is radiated approximately 360 degrees in the same direction regardless of the incident direction of the electrons, and the light traveling toward the front surface, which is the light emitting direction, is transmitted through the light transmissive member 11 and the lens. Head to 19. On the other hand, the light emitted from the phosphor 17 to the back (gate electrode 15 side) opposite to the light emitting direction is reflected by the reflecting surfaces of the reflectors 18a and 18b toward the light transmissive member 11, that is, in the light emitting direction. This light also passes through the light transmissive member 11 and travels toward the lens 19.

  In this way, each light directed toward the same lens 19 is emitted forward while being refracted and condensed by the condensing lens portions 19a, 19a. And in the structure of this Embodiment, the light which passed the condensing lens part 19a, 19a ... by the shape of reflector 18a, 18b and condensing lens part 19a, 19a ... is the optical axis of this vehicle lamp 10. The light distribution setting is such that a large amount of light gathers at a location P1 that is a predetermined distance away from the optical axis S with S as the center.

  Therefore, in the vehicular lamp 10 according to the present embodiment, the reflectors 18a and 18b are arranged so as to surround the back surface of the phosphor 17, and the light emitted to the cathode 16 side is emitted in the light emitting direction by the reflectors 18a and 18b. It is configured to be reflected toward a certain lens 19 and emitted forward. That is, the reflectors 18a and 18b are configured to reflect the light emitted from the phosphor 17 in the direction opposite to the light emission direction in the light emission direction, so that the light is emitted from the phosphor 17 to the side opposite to the light emission direction. Without wasting the light, it is possible to emit the emitted light forward by effectively emitting the light forward. In addition, it is possible to increase the range of light emission and the visibility.

  In the above embodiment, the structure using the lens 19 in which the condensing lens portions 19a, 19a,... Are arranged in a horizontal row is disclosed. However, for example, as shown in FIG. It may be an arranged structure or the like.

  In the above embodiment, the light passing through the condensing lens portions 19a, 19a,... Is centered on the optical axis S due to the shapes of the reflectors 18a, 18b and the condensing lens portions 19a, 19a,. The structure in which the light distribution is set so as to be concentrated at a location P1 that is a predetermined distance away from the upper side of the optical axis S has been disclosed. For example, as shown in FIG. The light distribution setting may be set so as to gather more at the locations P1 and P2. In FIG. 4, members denoted by the same reference numerals as those in FIGS. 1 and 2 are the same members as those in FIGS. 1 and 2. That is, the structure shown in FIG. 4 is different from the structure shown in FIGS. 1 and 2 only in the light distribution structure of the reflectors 18a and 18b, and the other configurations are the same, and thus detailed description thereof is omitted.

  The above-described vehicle lamp 10 has a structure suitable as a signal lamp such as a tail lamp, a turn signal lamp, and a stop lamp. For example, when the lamp is used as a headlamp, the structure shown in FIG. . The vehicular lamp 20 shown in FIG. 5 has the vehicular lamp 10 shown in FIG. 1 and FIG. 2 as a light source unit, and the other components are the same as those in FIG. 1 and FIG. Are denoted by the same reference numerals and redundant description is omitted.

  In FIG. 5, the vehicular lamp 20 has an example of a structure suitable as a low beam headlamp in this example, and a light source unit is provided in a lamp chamber 23 covered by a lamp body 21 and a light-transmissive lens cover 22. 24 is arranged. The light source unit 24 has the same structure as the vehicular lamp 10 shown in FIGS. 1 and 2, and is attached to the lamp body 21 via aiming mechanisms 25 and 25 that can adjust the optical axis S of the light source unit 24. ing.

  The lens cover 22 has a projection lens 22a formed by a convex lens at the center. In order to obtain a light distribution pattern suitable for use as a headlamp, the focal point of the projection lens 22a is substantially the center in the left and right and up and down directions of the condensing lens portions 19a, 19a. It is provided in the vicinity.

  In the vehicular lamp 20 configured as described above, the light emitted from the phosphor 17 and directed toward the front surface in the light emission direction is transmitted through the light transmissive member 11 toward the lens 19 and from the phosphor 17. The light emitted to the rear side (gate electrode 15 side) opposite to the light emitting direction is reflected in the light transmissive member 11 side by the reflecting surfaces of the reflectors 18a and 18b, that is, in the light emitting direction, and passes through the light transmissive member 11. The light passes through to the lens 19.

  Further, each light directed toward the lens 19 is emitted forward while being refracted and condensed by the condensing lens portions 19a, 19a, and is further emitted to the outside through the projection lens 22a to function as a headlamp.

  Therefore, in the vehicular lamp 20 according to the present embodiment, the light emitted to the cathode 16 side is reflected by the reflectors 18a and 18b to the lens 19 side and emitted forward. The light emitted from 17 to the opposite side to the light emitting direction is emitted to the front in the light emitting direction without being wasted, and the emitted light can be effectively used. Thereby, even if it is small, a bright vehicle lamp can be obtained.

  The preferred embodiments of the present invention have been described above. However, the present invention can be variously modified and changed without departing from the concept of the claims.

  For example, in the above-described embodiment, the vehicular lamp 20 has been described using the low beam headlamp as an example. However, by changing the lens cover 22, the vehicular lamp 20 may be used as a driving headlamp. is there.

1 is an external perspective view of a vehicular lamp shown as an embodiment of the present invention. It is the sectional view on the AA line of FIG. It is a perspective view which shows one modification of the lens which can be used with a vehicle lamp same as the above. It is sectional drawing of the vehicle lamp shown as other embodiment of this invention. It is sectional drawing of the vehicle lamp shown as further another embodiment of this invention. It is sectional drawing of the conventional vehicle lamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle lamp 11 Light transmissive member 12 Vacuum container 13 Space 14 Anode 15 Lossless gate electrode 16 Cathode 17 Phosphor 18a Reflector 18b Reflector 19 Lens 19a Condensing lens part 20 Vehicle lamp 21 Lamp body 22 Lens cover
22a Projection lens 23 Lamp chamber 24 Light source unit 25 Aiming mechanism S Optical axis

Claims (3)

An anode and a cathode that are spaced apart from each other to form an electric field; and a phosphor made of a fluorescent material arranged in the electric field, and the fluorescence of the phosphor by electrons emitted from the cathode toward the anode A field emission lamp type vehicle lamp in which a substance is excited and emits light,
A vehicular lamp characterized in that a reflector is provided on the back side of the phosphor. 2. The vehicular lamp according to claim 1, wherein a plurality of condensing lenses are arranged to face the phosphor. The vehicular lamp according to claim 1 or 2, wherein a projection lens having a focal point is provided in the vicinity of a substantially center of the plurality of condenser lenses.

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