CROSS-REFERENCE TO THE RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2020-0112262, filed on Sep. 3, 2020, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a lighting device configured for controlling a light radiation direction and having a simple structure for controlling the light radiation direction.

Description of Related Art

In general, a vehicle is provided with various types of lighting devices to facilitate recognition of objects present near the vehicle when traveling in a dimly lit environment and to notify other vehicles or pedestrians of the traveling state of the vehicle. Among the vehicle lighting devices, headlamps, also called headlights, are configured to illuminate the area in front of the vehicle.

Because headlamps are fixedly mounted to the front side of a vehicle, the headlamps may dazzle drivers of other vehicles or pedestrians or may be incapable of appropriately radiating light toward the area in front of the subject vehicle, thus failing to illuminate the field of view of the driver of the subject vehicle, depending on the driving conditions (e.g., change in the vehicle posture), road conditions, and ambient conditions.

Therefore, a configuration for aiming an optical module is applied to headlamps. However, due to a trend of reduction in the size of an external lamp, it is difficult to aim an optical module in a small or slim lamp. An actuator is required to aim an optical module. However, because an actuator is relatively large, space for mounting the actuator needs to be secured. Furthermore, in the case in which a plurality of optical modules is provided, each of the optical modules requires an individual actuator, and thus it is difficult to make headlamps small or slim.

The information included in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and may not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a lighting device configured for controlling a light radiation direction and having a simple structure for controlling the light radiation direction thereof, reducing the overall volume thereof when a plurality of lamp modules is applied thereto.

In accordance with various aspects of the present invention, the above and other objects may be accomplished by the provision of a lighting device configured for controlling a light radiation direction thereof, the lighting device including a housing provided with a light source configured to radiate light, a lens unit provided in the housing to be changeable in position thereof and configured to concentrate light generated from the light source, a length-variable unit mounted to the housing to be connected to the lens unit and configured such that the length thereof is changed in a response to application of electricity thereto in the direction in which the position of the lens unit is configured for being changed to change the position of the lens unit, and a controller configured to control a light radiation direction of the lens unit by setting the voltage of electricity to be applied to the length-variable unit so that the length of the length-variable unit is changed according to the set voltage and the position of the lens unit is changed according to the change in the length of the length-variable unit.

The housing may include a through-hole formed at a position of the housing corresponding to the lens unit. The lens unit may include a condensing lens portion formed to concentrate the light incident thereon from the light source and a sliding portion extending from the periphery of the condensing lens portion to be slidably inserted into the through-hole.

The length-variable unit may be mounted outside the housing, and may be connected to the sliding portion of the lens unit so that the sliding portion moves through the through-hole according to the change in the length of the length-variable unit.

The through-hole may include an upper through-hole formed in the housing at a position above the condensing lens portion of the lens unit and a lower through-hole formed in the housing at a position below the condensing lens portion of the lens unit. The sliding portion may include an upper sliding portion extending from an upper portion of the condensing lens portion to be inserted into the upper through-hole and a lower sliding portion extending from a lower portion of the condensing lens portion to be inserted into the lower through-hole.

The lighting device may further include an elastic restoring unit having elastic restoring force to return the lens unit, having been moved by the length-variable unit, to the original position of the lens unit. One of the upper sliding portion and the lower sliding portion of the lens unit may be connected to the length-variable unit, and the remaining one of the upper sliding portion and the lower sliding portion may be connected to the elastic restoring unit.

The length-variable unit may include a first length-variable unit and a second length-variable unit configured to change in length in different directions from each other upon application of electricity thereto. The first length-variable unit and the second length-variable unit may be respectively connected to the upper sliding portion and the lower sliding portion of the lens unit.

The length-variable unit may include a support portion configured to be bendable and connected to the lens unit and a piezoelectric portion attached to the support portion and configured to be changeable in length upon receiving of the electricity to cause the support portion to bend.

The lighting device may further include a light distribution lens mounted in the housing so that the light that has passed through the lens unit is incident thereon and is radiated in a set direction therethrough.

The housing may be provided with a moving shaft vertically penetrating the housing in an upward-downward direction to be movable. The light distribution lens may be connected to the moving shaft to be tilted according to the change in the position of the moving shaft.

The housing may be further provided with a light-distribution-control length-variable unit connected to the moving shaft.

The controller may receive vehicle posture information according to movement of a vehicle and may control the length-variable unit to move the lens unit upwards or downwards based on the posture of the vehicle according to movement of the vehicle in the upward-downward direction thereof.

The controller may receive vehicle travel information on the travel state of a vehicle and may control the length-variable unit to move the lens unit upwards or downwards according to the traveling speed of the vehicle.

The controller may receive temperature information and may control the length-variable unit based on pre-stored data on the influence of temperature on the length-variable unit to compensate for a change in the length of the length-variable unit caused by the temperature.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

