JP2022139856A - Lighting device and vehicular lamp fitting - Google Patents

Abstract

To provide a lighting device which can prevent deformation and discoloration of a lens from being caused by heat generated by a light source.SOLUTION: A lighting device includes: a light source 2; a lens 3 disposed in front of the light source 2; and a lens moving mechanism 4 for moving the lens 3 in an anteroposterior direction relative to the light source 2. The lens moving mechanism 4 has a thermal expansion member 8 disposed between the light source 2 and the lens 3. The lens 3 is moved forward when the thermal expansion member 8 expands in response to heat generated by the light source 2. The lens 3 is moved backward when the thermal expansion member 8 contracts.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lighting device and a vehicle lamp.

2. Description of the Related Art In recent years, lighting devices including vehicle lamps have increasingly adopted LEDs as light sources as light-emitting diodes (LEDs) have become brighter and less expensive. LEDs have the advantages of long life and low power consumption. On the other hand, when the temperature rises, the luminous efficiency is lowered and the life is shortened, so the allowable rated temperature is determined.

Some lighting devices have a function (temperature derating function) for suppressing the temperature rise due to the heat generated by the light source (for example, see Patent Document 1 below). Specifically, the temperature of the light source is detected by a thermistor so that the temperature of the light source does not exceed the rated temperature. It is

In addition, the temperature derating function also prevents the temperature of the electronic parts in the lighting circuit from exceeding the rated temperature due to the heat generated by the light source, and prevents deformation and discoloration of the resin parts such as the lens placed in front of the light source. .

JP 2016-091730 A

By the way, the conventional lighting device requires a large number of electronic components for performing the above-described derating control, which is one of the factors that increase the cost. Also, if an electrical problem occurs, it is fatal for derating control.

For this reason, there is a possibility that the lens arranged in front of the light source will be deformed or discolored due to the temperature rise of the light source. Therefore, it is desired to prevent deformation and discoloration of the lens due to the heat generated by the light source, regardless of the derating control described above.

SUMMARY OF THE INVENTION The present invention has been proposed in view of such conventional circumstances. The purpose is to provide lighting fixtures for

In order to achieve the above object, the present invention provides the following means.
[1] a light source;
a lens positioned in front of the light source;
a lens moving mechanism for moving the lens in the front-rear direction with respect to the light source;
The lens moving mechanism has a thermal expansion member arranged between the light source and the lens,
moving the lens forward when the thermal expansion member expands according to the heat emitted by the light source, and moving the lens backward when the thermal expansion member contracts; A lighting device characterized by:
[2] The lighting device according to [1], wherein the thermal expansion member comprises a ring-shaped elastic bag in which gas is sealed.
[3] The lens moving mechanism includes a ring-shaped fixed member surrounding the light source, and a ring-shaped moving member attached so as to be movable in the front-rear direction with respect to the fixed member while holding the lens. has
The lighting device according to [1] or [2], wherein the thermal expansion member is arranged in a state of being sandwiched between the fixed member and the movable member.
[4] comprising a substrate on which the light source is arranged;
The illumination device according to [3], wherein the fixing member is attached to the substrate.
[5] A vehicle lamp comprising the lighting device according to any one of [1] to [4].

As described above, according to the present invention, it is possible to provide a lighting device capable of preventing deformation and discoloration of a lens due to heat generation of a light source, and a vehicle lamp equipped with such a lighting device. be.

1 is a perspective view showing the configuration of a vehicle lamp provided with a lighting device according to an embodiment of the present invention; FIG. It is an exploded perspective view showing composition of a lighting installation. It is a see-through|perspective side view which shows the structure of an illuminating device. It is the perspective view which looked at the lens moving mechanism from the back. It is the perspective view which looked at the lens moving mechanism from the front. It is a cross-sectional perspective view which shows the structure of a lens moving mechanism.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As an embodiment of the present invention, a vehicle lamp 100 including the lighting device 1 shown in FIGS. 1 to 6, for example, will be described.

1 is a perspective view showing the configuration of a vehicle lamp 100 including the lighting device 1. FIG. FIG. 2 is an exploded perspective view showing the configuration of the lighting device 1. As shown in FIG. FIG. 3 is a see-through side view showing the configuration of the illumination device 1. As shown in FIG. FIG. 4 is a perspective view of the lens moving mechanism 4 as seen from the rear. FIG. 5 is a perspective view of the lens moving mechanism 4 as seen from the front. FIG. 6 is a cross-sectional perspective view showing the configuration of the lens moving mechanism 4. As shown in FIG.

In the drawings shown below, an XYZ orthogonal coordinate system is set, the X-axis direction is the front-rear direction of the lighting device 1 (vehicle lamp 100), the Y-axis direction is the left-right direction of the lighting device 1 (vehicle lamp 100), The Z-axis direction is shown as the vertical direction of the lighting device 1 (vehicle lamp 100). Depending on the form of the lighting device 1 (vehicle lamp 100), the front-rear direction, left-right direction, and vertical direction in an actual vehicle may differ. 100) is set for convenience.

The lighting device 1 of the present embodiment is a vehicle lamp 100 mounted on a vehicle, for example, a vehicle headlamp (headlamp) that emits illumination light toward the front of the vehicle (+X-axis direction). applied.

Specifically, as shown in FIGS. 1 and 2, the illumination device 1 includes a light source 2, a lens 3 arranged in front of the light source 2, and a lens for moving the lens 3 in the front-rear direction with respect to the light source 2. A moving mechanism 4 is provided.

The light source 2 consists of a light emitting diode (LED) that emits white light (hereinafter simply referred to as "light"). The light source 2 is mounted on one surface (the front surface in this embodiment) of a circuit board 5 on which a drive circuit for driving the LEDs is provided. Further, the circuit board 5 is arranged with one surface facing forward (+X-axis side) of the vehicle. As a result, the light source 2 emits light toward the front of the vehicle (+X axis side).

The circuit board 5 is provided with a drive circuit for driving the LEDs described above. The mounting board and the circuit board may be electrically connected via a wiring cord called a harness to protect the drive circuit from the heat generated by the LED.

The lens 3 is made of a light transmissive member that guides the light emitted from the light source 2 . For the light-transmissive member, a material having a higher refractive index than air, such as transparent resin such as polycarbonate or acrylic, or glass, can be used.

In this embodiment, a cylindrical lens 3 is illustrated, but the shape of the lens 3 is not particularly limited. For example, a convex lens that projects light emitted from the light source 2 forward. etc., can be changed as appropriate.

As shown in FIGS. 3 to 6, the lens moving mechanism 4 includes a ring-shaped fixed member 6 attached to the circuit board 5 and a ring-shaped moving member attached to the fixed member 6 so as to be movable in the front-rear direction. It has a member 7 and a thermal expansion member 8 arranged between the light source 2 and the lens 3 .

The fixing member 6 includes a substantially cylindrical inner cylinder portion 6a located on the inner peripheral side, a substantially cylindrical outer cylinder portion 6b located on the outer peripheral side, and a plurality of (in this embodiment, 4) wall portions 6c.

The plurality of wall portions 6c are arranged side by side at equal intervals in the circumferential direction of the fixing member 6, and connect the inner cylinder portion 6a and the outer cylinder portion 6b in a covered state. Further, on the back side of the fixing member 6, a plurality of (four in the present embodiment) grooves 6d are provided by notching in the radial direction between the walls 6c adjacent to each other.

On the other hand, the circuit board 5 is provided with a plurality of (four in this embodiment) fixing holes 5a into which the plurality of wall portions 6c are fitted. The plurality of fixing holes 5a have shapes corresponding to the plurality of wall portions 6c and are arranged side by side at equal intervals in the circumferential direction around the light source 2 .

The fixing member 6 is attached to the front side of the circuit board 5 while surrounding the light source 2 by fitting a plurality of walls 6c into the plurality of fixing holes 5a.

The moving member 7 includes a substantially cylindrical inner cylinder portion 7a located on the inner peripheral side, a substantially cylindrical outer cylinder portion 7b located on the outer peripheral side, and a plurality of (in this embodiment, 4) wall portions 7c.

The plurality of wall portions 7c are arranged side by side at equal intervals in the circumferential direction of the moving member 7, and radially connect the inner cylinder portion 7a and the outer cylinder portion 7b. In order to reduce the weight of the moving member 7, each wall portion 7c is provided with a hole portion 7d.

The moving member 7 is inserted between the inner cylinder portion 6a and the outer cylinder portion 6b from the front side of the fixing member 6, and is attached to the fixing member 6 so as to be movable in the front-rear direction. In addition, the inner cylindrical portion 7a of the moving member 7 holds the periphery of the lens 3 on the rear end side.

The thermal expansion member 8 is made of a ring-shaped elastic bag containing gas (air in this embodiment). The thermal expansion member 8 is inserted between the inner cylindrical portion 7a and the outer cylindrical portion 7b from the rear side of the moving member 7, thereby providing a space between the wall portion 6c of the fixed member 6 and the wall portion 7c of the moving member 7. placed in a state of being sandwiched between

In the illumination device 1 of the present embodiment having the configuration described above, the thermal expansion member 8 is heated by the heat emitted by the light source 2 when the light source 2 is turned on. At this time, in the lens moving mechanism 4, the thermal expansion member 8 expands between the fixed member 6 and the moving member 7, and the moving member 7 pressed by the expanded thermal expansion member 8 moves forward. do. Thereby, in the illumination device 1 of the present embodiment, the lens 3 can be moved forward with respect to the light source 2 .

On the other hand, since the lens 3 moved forward is separated from the light source 2, heating of the thermal expansion member 8 by the heat generated by the light source 2 is suppressed, and the thermal expansion member 8 is cooled. At this time, in the lens moving mechanism 4, the thermal expansion member 8 shrinks between the fixed member 6 and the moving member 7, so that the moving member 7 moves rearward together with the thermal expansion member 8 that has contracted. Thereby, in the illumination device 1 of the present embodiment, the lens 3 can be moved rearward with respect to the light source 2 .

As described above, in the illumination device 1 of the present embodiment, when the thermal expansion member 8 expands in response to the heat emitted by the light source 2, the lens 3 is moved forward, and the thermal expansion member 8 When contracted, it is possible to move the lens 3 backwards.

Therefore, in the illumination device 1 of the present embodiment, it is possible to prevent deformation and discoloration of the lens 3 due to heat generation of the light source 2 without depending on conventional derating control. In addition, since electronic components for performing derating control are not required, cost reduction is possible.

It should be noted that the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.
For example, although the thermal expansion member 8 is configured to contain air as a gas, it may be configured to contain a gas having a higher coefficient of thermal expansion than air. Alternatively, instead of gas, a liquid such as oil may be enclosed. Furthermore, it is also possible to use a bimetal or the like as the thermal expansion member 8 .

In the above-described embodiment, the present invention is applied to a vehicle headlamp (headlamp). Instead, it is also possible to apply the present invention to a rear vehicle lamp such as a rear combination lamp.

Further, the vehicular lamp to which the present invention is applied is not limited to the vehicle headlamp (headlamp) described above, and may be, for example, a tail lamp (tail lamp), a width lamp (position lamp), an auxiliary headlamp ( Sub head lamp), front (rear) fog lamp (fog lamp), daytime lighting (daytime running) lamp, lid lamp, brake lamp (stop lamp), back lamp, direction indicator (winker lamp), etc. The present invention can be widely applied to lighting fixtures.

Further, for the light source 2, a light-emitting element such as a laser diode (LD) can be used in addition to the above-described LED. Further, the color of the light emitted by the light-emitting element is not limited to the white light described above, and can be appropriately changed to red light, orange light, or the like, depending on the application of the light source.

Furthermore, although the lighting device to which the present invention is applied is suitably used for the above-described vehicle lamp, it is not necessarily limited to the one applied to the vehicle lamp. That is, the present invention can be applied to general lighting devices such as residential lighting devices, projector lighting devices, and the like.

DESCRIPTION OF SYMBOLS 1... Lighting apparatus 2... Light source 3... Lens 4... Lens moving mechanism 5... Circuit board 6... Fixed member 7... Moving member 8... Thermal expansion member 100... Vehicle lamp

Claims (5)

a light source;
a lens positioned in front of the light source;
a lens moving mechanism for moving the lens in the front-rear direction with respect to the light source;
The lens moving mechanism has a thermal expansion member arranged between the light source and the lens,
moving the lens forward when the thermal expansion member expands according to the heat emitted by the light source, and moving the lens backward when the thermal expansion member contracts; A lighting device characterized by: 2. The lighting device according to claim 1, wherein the thermal expansion member comprises a ring-shaped elastic bag filled with gas. The lens moving mechanism has a ring-shaped fixed member surrounding the light source, and a ring-shaped moving member attached so as to be movable in the front-rear direction with respect to the fixed member while holding the lens. ,
3. The lighting device according to claim 1, wherein the thermal expansion member is sandwiched between the fixed member and the movable member. A substrate on which the light source is arranged,
4. The lighting device according to claim 3, wherein the fixing member is attached to the substrate. A vehicle lamp comprising the lighting device according to any one of claims 1 to 4.

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