GB2632861A

GB2632861A - Lamp assembly

Info

Publication number: GB2632861A
Application number: GB2312964.6A
Authority: GB
Inventors: Onley Ben; Dunn John
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2023-08-25
Filing date: 2023-08-25
Publication date: 2025-02-26
Also published as: GB202312964D0

Abstract

Aspects of the present invention relate to a lamp assembly (200) for a vehicle (10), the lamp assembly comprising: a lamp assembly enclosure (302), the enclosure having an opening; a lens (312) located at the opening of the enclosure; a light source (304) in the form of a light emitting diode (LED) located within the lamp assembly enclosure and positioned behind the lens; and heat dissipation means (700, 800) configured to direct heat generated by the light source in use towards the lens.

Description

LAMP ASSEMBLY

TECHNICAL FIELD

The present disclosure relates to a lamp assembly. Aspects of the invention relate to a lamp assembly, a headlamp, a lighting system, a control system, a method for controlling a lamp assembly and a vehicle.

BACKGROUND

In cold weather ice/condensation forms on a vehicle, including on headlights and other lights on the vehicle. This ice/condensation can obscure the lamps thereby reducing their effectiveness. Vehicle users therefore need to manually remove the ice prior to commencing a journey.

It is an aim of the present invention to address one or more of the disadvantages associated with known ice/condensation removal techniques.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a lamp assembly, a headlamp, a lighting system, a control system, a method for controlling a lamp assembly and a vehicle as claimed in the appended claims According to an aspect of the present invention there is provided a lamp assembly for a vehicle, the lamp assembly comprising: a lamp assembly enclosure, the enclosure having an opening; a lens located at the opening of the enclosure; a light source in the form of a light emitting diode (LED) located within the lamp assembly enclosure and positioned behind the lens; and heat dissipation means configured to direct heat generated by the light source in use towards the lens.

The present invention provides a lamp assembly for a vehicle which incorporates heat dissipation means for directing heat generated by the light source in use towards the lens. Directing heat from the light source in this way would enable water-based obstructions on the lens, e.g. ice or misting of water vapour, to be removed, e.g. during vehicle conditioning. The heat dissipation means may comprise any suitable heat transfer device such as a heat pipe or an air duct for conveying hot air either directly from the region of the light source or from a heat sink towards the lens.

Optionally, the heat dissipation means may comprises a heat pipe. Heat pipes may comprise a sealed pipe or tube that is partially filled with a working fluid.

Optionally, the light source may be mounted on a printed circuit board, PCB, and one end of the heat pipe may be in communication with the PCB and the other end of the heat pipe may be in communication with the lens.

Optionally, the heat dissipation means may comprise an air duct and one end of the air duct may be in proximity to the light source and the other end of the air duct may be in proximity to the lens. The air duct may he comprise ducting within the lamp assembly enclosure. Alternatively, the internal surface of the lamp assembly enclosure may be used to direct air flow from a fan towards the lens.

Optionally, the light source may be mounted on a printed circuit board, the printed circuit board may be in thermal communication with a heatsink and the light assembly may comprise a fan located within the lamp assembly enclosure, the fan being configured to direct a flow of air across the heatsink and into the end of the air duct that is in proximity to the light source.

Optionally, the printed circuit board may be in communication with control system and configured to receive control signals for controlling the operation of the light source.

Optionally, the light source may be configured to operate at a first current level in normal operation and may be further configured to operate at a higher current level in response to a heating control signal from the control system.

Optionally, the printed circuit board may comprise a heating trace line and the printed circuit board may be configured to send current through the heating trace line in response to a heating control signal from the control system.

Optionally, the heating trace line may cornpnses a resistor.

Optionally, the lens may comprise heat conductive elements.

Optionally, the heat conductive elements may be in the form of etal pathways n a surface of the lens.

According to another aspect of the present invention there is provided a headlamp comprising the lamp assembly of the above aspect of the present invention.

According to a further aspect of the present invention there is provided a lighting system for a vehicle comprising the lamp assembly of the above aspect of the present invention and a control system for controlling the lamp assembly.

According to a still further aspect of the present invention there is provided a vehicle comprising the lamp assembly of the above aspect of the present invention.

According to an example useful for understanding the present invention there is provided a control system for controlling a lamp assembly of a vehicle, the control system comprising one or more processors collectively configured to: receive sensor data from a vehicle sensor; determine the presence of a water-based obstruction on a lens of the lamp assembly in dependence on the received sensor data; generate a heating control signal to control the lamp assembly to increase heat generated within the lamp assembly that is transmitted to the lens; output the heating control signal to the lamp assembly.

The present example useful for understanding the present invention provides a control system for controllino the lamp assembly of a vehicle to increase the level of heat that is transmitted to the lens of the lamp assembly in the event the control system determines the presence of a water-based obstruction, such as ice build up or misting of water vapour, on the lens of the lamp assembly (depending on the nature of the received sensor data, determining the presence of a water-based obstruction may comprise observing the presence of a water-based obstruction, e.g. if image data from a camera with a field of view covering the lens is used, or may comprise inferring or predicting that a water-based obstruction is present, e.g. if temperature/humidity is used). The control system may be configured to redirect heat from the light source towards the lens (e.g. by turning on or redirecting the airflow from a fan within the lamp assembly) and/or to control the light source to generate more heat (e.g. by increasing the current through the light source compared to a normal operating current range) and/or pass current through additional electrical components within the lamp assembly.

Optionally, the lamp assembly may comprise at least two headlamps, the control system being configured to turn on each vehicle headlamp individually and to determine whether each headlamp is obscured.

Optionally, where the vehicle comprises a plurality of lamp assemblies, the control system may be configured to output the heating control signal to each lamp assembly if the presence of a water-based obstruction has been determined on one or more of the plurality of lamp assemblies. In this way all lights and lamp assemblies on the vehicle may be switched to a defrost mode even if the control system has determined that only one lamp is affected by a water-based obstruction.

Optionally, where the vehicle comprises a plurality of lamp assemblies, the control system may be configured to output the heating control signal to each lamp assembly for which the presence of a water-based obstruction has been determined. In this way the control system may control each lamp assembly independently such that only those lamp assemblies that are impacted by a water-based obstruction will be placed into a defrost mode.

Optionally, the vehicle may comprise a camera with a field of view that encompasses the lamp assembly and the sensor data may comprise image data from the camera, the control system being configured to run an image recognition process to identify the presence of a water-based obstruction on the lamp assembly.

Optionally, the sensor data may comprise temperature and humidity data and the control system may be configured to predict the presence of the water-based obstruction on the lamp assembly in dependence on the received temperature and humidity data.

Optionally, the heating control signal may comprise a control signal configured to send a current through a trace circuit of a printed circuit board within the lamp assembly in order to generate heat.

Optionally, the lamp assembly may comprise multiple light sources and the heating control signal may comprise a control signal to turn on all light sources simultaneously to increase heat generation within the lamp assembly.

Optionally, the heating control signal may comprise a control signal to increase forward current through the or each light source in the lamp assembly.

Optionally, the control system may be configured to generate the heating control signal during vehicle preconditioning.

Optionally, the heating control signal may comprise a control signal for a fan within the lamp assembly.

According to another example useful for understanding the present invention there is provided a system comprising the control system (10) of the above example useful for understanding the present invention and a lamp assembly of a vehicle.

The example useful for understanding the present invention extends to a vehicle comprising the above system or the above control system.

According to a further example useful for understanding the present invention there is provided method for controlling a lamp assembly of a vehicle, the method comprising: receiving sensor data from a vehicle sensor; determining the presence of a water-based obstruction on a lens of the lamp assembly in dependence on the received sensor data; generating a heating control signal to control the lamp assembly to increase heat generated by a light source within the lamp assembly that is transmitted to the lens; outputting the heating control signal to the lamp assembly.

The example useful for understanding the present invention extends to computer readable instructions which, when executed by a computer, are arranged to perform the above method for controlling a lamp assembly of a vehicle.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination.

That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a vehicle in accordance with an embodiment of the present invention; Figure 2 shows a light assembly for a vehicle; Figure 3 shows a schematic of a known light assembly for a vehicle; Figure 4 shows a schematic of a light assembly for a vehicle in accordance with an embodiment of the present invention; Figure 5 shows a control system in accordance with an embodiment of the present invention for controlling a light assembly; Figure 6 shows a method of controlling the control system of Figure 5 in accordance with an embodiment of the present invention; Figure 7 shows a schematic of a light assembly for a vehicle in accordance with an embodiment of the present invention; Figure 8 shows a schematic of a light assembly for a vehicle in accordance with an embodiment of the present invention; and Figure 9 shows a current-voltage plot for a light source used in accordance with an embodiment of the invention.

DETAILED DESCRIPTION

A vehicle 10 in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figure 1.

With reference to Figure 1, the vehicle 10 comprises a control system 100 (described in more detail with reference to Figure 5) and a lamp assembly 200. The control system 100 is in communication with a vehicle sensor 130.

Referring to Figure 2, a lamp assembly in the form of a headlamp assembly 200 is shown that includes a transparent lens cover 202. The lens cover 202 covers several headlamps, such as high beam headlamp 203 and low beam headlamp 205. A first lens 207 is positioned in front of the high beam headlamp 203, and a second lens 209 is positioned in front of the low beam headlamp 205, to focus and/or directionally refract light from their respective headlamps. The light sources for the headlamps within the headlamp assembly 200 are in the form of a light emitting diode (LED) light.

It will be understood that each LED light within the headlamps may include one or more LEDs along with any reflecting and/or refracting features needed to focus, collimate or defocus the light from the LED(s) so that it moves in the desired direction with the desired dispersion characteristics.

In this embodiment, the lamp assembly is for a headlamp, but in other embodiments may be for an indicator, fog light, taillight or any other light of the type used in vehicle lamp assemblies.

Figure 3 is a schematic representation of a known lamp assembly. The lamp assembly 200 comprises a lamp assembly enclosure 302 which encloses an LED light source 304 which is mounted on a printed circuit board (PCB) 306. A heatsink 308 is also mounted on the PCB 306 along with a fan 310. The lamp assembly enclosure has an opening at one end within which is mounted a lens 312.

In use, the LED light source 304 emits light 314 towards the lens 312 and an output beam of light 316 then leaves the lamp assembly 200. The heatsink 308 and fan 310 operate to circulate air 318 in order to dissipate heat from the lamp assembly 200.

Figure 4 is a schematic representation of lamp assembly in accordance with an embodiment of the present invention. Like features between Figures 3 and 4 are denoted by like reference numerals.

In the lamp assembly 200 of Figure 4, one or more vent holes 400 are present to provide an airflow path from the fan side of the PCB 306 to the light source side of the PCB. Such one or more vent holes 400 may either separate the PCB 306 from the lamp assembly enclosure 302 or may comprise a through hole through the PCB 306 itself In use, the light source 304 is switched on and generates light 314 and also waste heat energy. The heat energy is removed from the PCB 306 by the heatsink 308 and the air surrounding the heatsink is heated. The fan 310 is driven, in response to a control signal 155 that is received from the control system 100 at the PCB 306, to direct this now heated air 402 from the heat sink 308 towards the vent hole(s) 400 and subsequently towards the lens 312. Heat energy is then dissipated through the lens 312. In the event that the lens 312 is obscured with a water based obstruction such as ice or condensed water vapour then the heat from the light source either melts the ice or causes the condensed water vapour to evaporate from the lens 312. It is noted that the lens 312 may additionally be covered by a lens cover. It is further noted that, compared to Figure 3, the control signal 155 may be operative to reverse the fan direction such that the direction that hot air 402 is driven is reversed (cf air flow direction 318 in Figure 3 versus air flow direction 402 in Figure 4).

Figure 5 shows the control system 100 for the vehicle 10 according to an embodiment of the present invention. The control system 100 comprises one or more controllers 110.

The control system 100 is configured to receive vehicle sensor data 135 from a vehicle sensor 130 and determine the presence of a water-based obstruction on a lens of the lamp assembly 200. The control system may then output the control signal 155 to control the lamp assembly 200 to direct heat generated by a light source within the lamp assembly towards the lens.

The control system 100 as illustrated in Figure 5 comprises one controller 110, although it will be appreciated that this is merely illustrative. The controller 110 comprises processing means 120 and memory means 125.

The processing means 120 may be one or more electronic processing device 120 which operably executes computer-readable instructions. The memory means 125 may be one or more memory device 125. The memory means 125 is electrically coupled to the processing means 120. The memory means 125 is configured to store instructions, and the processing means 120 is configured to access the memory means 125 and execute the instructions stored thereon.

The controller 110 comprises an input means 140 and an output means 150. The input means 140 may comprise an electrical input of the controller 110. The output means 150 may comprise an electrical output of the controller 110. The input 140 is arranged to receive a vehicle sensor signal 165 from a vehicle sensor.

The vehicle sensor signal 165 is an electrical signal which is indicative of the vehicle sensor data 135. The output 150 is arranged to output a heating control signal 155 for controlling the lamp assembly 200 to direct heat generated by a light source towards the lens.

Figure 6 illustrates a method 600 of controlling a lamp assembly 200 of a vehicle 10 according to an embodiment of the invention. The method 600 may be performed by the control system 100 illustrated in Figure 5 with the lamp assembly 200 of Figure 4. In particular, the memory 130 may comprise computer-readable instructions which, when executed by the processor 120, perform the method 600 according to an embodiment of the invention.

It is noted that the control system 100 of Figure 5 and method 600 of Figure 6 may also be used with the lamp assemblies described in Figures 7 and 8 below.

Turning to Figure 6 again, the control system receives, at 602, sensor data 135 from a vehicle sensor. In 604, the control system 100 is configured to determine the presence of a water-based obstruction on a lens of the lamp assembly 200 in dependence on the received sensor data 135. In 606, the control system 100 is configured to generate a heating control signal 155 which, in the event that the presence of a water-based obstruction on a lens of the lamp assembly 200 is determined in step 604, controls the lamp assembly 200 to direct heat generated by a heat source (e.g. the light source 304) within the lamp assembly towards the lens. This may comprise controlling a fan 310 to blow hot air in a different direction (e.g. to switch the direction of air circulation from that shown in Figure 3 to that shown in Figure 4) It may instead or also comprise controlling the fan in a light assembly comprising a heat pipe to equalise the internal light assembly temperature with the heat pipe (which would lower the light source temperature by increasing the light assembly enclosure temperature). It may also or instead comprise controlling the fan to direct air towards an air duct (as shown in Figure 8). The control signal 155 may also control the lamp assembly to generate more heat, e.g. by passing current through a trace line on the PCB 306 or through an electronic component, such as a resistor.

The vehicle sensor 130 may comprise any vehicle sensor that outputs sensor data 135 that may be used to determine if a water-based obstruction is covering or partially covering the lens of a lamp assembly 200.

For example, the vehicle sensor 130 may comprise a camera with a field of view that encompasses the lamp assembly and the sensor data 135 comprises image data from the camera. The camera may be located within the light assembly enclosure 302 or may be located elsewhere on the vehicle (for example, a parking camera with an appropriate field of view may be used to identify water-based obstructions on the light assemblies 200 of the vehicle. Where the vehicle sensor 130 comprises a camera, the control system 100 may be configured to run an image recognition process to identify the presence of a water-based obstruction on the lamp assembly 200.

Alternatively, the vehicle sensor 130 may comprise a temperature and humidity sensor and the sensor data 135 comprises temperature and humidity data and the control system is configured to predict the presence of a water-based obstruction on the lens assembly in dependence on the received temperature and humidity data.

Alternatively, the vehicle sensor 130 may comprise a temperature probe disposed on the lens and the sensor data 135 may comprise temperature data. The processing means 120 may be arranged to output a control signal 155 to apply a known power to heat the lens and may monitor the temperature of the probe. The presence of water on the lens may be determined by the temperature probe having a higher thermal mass than expected due to the presence of a water based obstruction. Additionally, as the temperature probe reaches 0 degrees Celsius the latent heat of fusion associated with melting ice on the lens will cause warming of the temperature probe to stall.

Alternatively, the vehicle sensor 130 may comprise a first light sensor in the light assembly outside of the light path. The light sensor may be located in a well within the enclosure 302 such that under normal circumstances it receives zero light. When the lens is obscured by a water-based obstruction light will be back scattered into the light well and be detected by the sensor. Upon receiving a signal from the light sensor the processing means 120 may be configured to output the control signal 155. A second sensor may optionally be located outside the lens to enable the processing means 120 to determine if the vehicle has been parked near a reflective surface. This would enable the processing means to distinguish between external reflections to the light sensor and internal reflections due to backscattering.

Where the vehicle 10 comprises multiple light assemblies 200, the control signal 155 may be configured to control all light assembles in such a way as to direct heat generated by their light sources towards their respective lenses even if the received sensor data only indicates a single light assembly 200 is obscured by a water based obstruction. Similarly, where there are multiple light sources within a particular light assembly 200 the control signal may be configured to control all light sources to generate additional waste heat even if the received sensor data only indicates a single light assembly 200 is obscured by a water based obstruction.

Alternatively, the control signal may be configured to control each light assembly 200 independently, e.g. only light assemblies that are obscured by a water based obstruction may be controlled to direct heat generated by their light sources towards their respective lenses.

Figure 7 is a schematic representation of lamp assembly 200 in accordance with an embodiment of the present invention. Like features between Figures 3, 4 and 7 are denoted by like reference numerals.

The lamp assembly 200 of Figure 7 does not comprise a fan as shown in the embodiment of Figure 4. The lamp assembly 200 shown in Figure 7 instead comprises a heat pipe 700, a first end 702 of which is in contact with the PCB 306 and a second end 704 of which terminates in the vicinity of the lens 312.

In use, heat generated by the PCB 306 and/or the light source 304 is conveyed along the heat pipe 700 and is dissipated from the lamp assembly 200 through the lens 312.

To aid heat transfer through the lens 312, the lens comprises heat conductive elements 706 on the surface thereof, e.g. metal pathways that facilitate the conduction of heat from the second end 704 of the heat pipe 700 through the lens 312 to the outside environment. Although not shown in Figures 4 and 8 it is to be appreciated that the heat conductive elements 706 may be associated with any of the lamp assembles 200 in accordance with embodiments of the present invention.

The control signal 155 that is sent from the control system 100 to the lamp assembly 200 is represented by the arrow entering the lamp assembly 200 from the top and then connecting to the PCB 306.

The control signal 155 may control the light source 304 to generate additional heat during a defrost function on the vehicle 10. The control signal 155 may also control the PCB 306 to send electrical current through an electrical component 708 (such as a trace line on the PCB or a separate component like a resistor) to generate additional heat that may be utilised during a defrost function on the vehicle. Although not shown in Figure 4 it is to be appreciated that the electrical component 708 may be associated with any of the lamp assembles 200 in accordance with embodiments of the present invention.

Figure 8 is a schematic representation of lamp assembly 200 in accordance with an embodiment of the present invention. Like features between Figures 3, 4, 7 and 8 are denoted by like reference numerals.

The lamp assembly 200 of Figure 8 comprises a fan 310 that is controlled by the incoming control signal 155 from the control system 100 to direct hot air from the heat sink 308 through an air duct 800 on one wall of the enclosure 302. Ducted hot air 802 passes through the air duct 800. As the hot air passes over the enclosure-side surface of the lens 312 in region 804, heat energy is transferred to the lens and then through the lens 312 where it is dissipated to the outside environment. Cool air 806 circulates back to the fan 310 through air duct 801. Figure 8 may represent either a horizontal or vertical cross section of the lamp assembly depending on the particular lamp assembly configuration. In the event that Figure 8 represents the vertical cross section of the lamp assembly then it is noted that the fan is configured to direct the hot air flow in a direction that additionally supports a thermosyphoning effect.

The lamp assembly of Figure 8 additionally comprises the component 708 as described in relation to Figure 7.

Figure 9 shows a current versus voltage plot for an LED light source 304. Two voltage-current profiles are shown, the first profile 902 shows an operating temperature of 25 degrees Celsius and the second profiles 904 shows an operating temperature of 50 degrees Celsius. As described above, the control system 100 is configured to control the light assembly 200 via the control signal 155. In the event that the light assembly 200 is controlled in this manner then additional heat will be generated that may be used during a defrost or demisting cycle to remove water-based obstructions from the lens of one or more light assemblies on the vehicle.

It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

CLAIMS1. A lamp assembly for a vehicle, the lamp assembly comprising: a lamp assembly enclosure, the enclosure having an opening; a lens located at the opening of the enclosure; a light source in the form of a light emitting diode (LED) located within the lamp assembly enclosure and positioned behind the lens; and heat dissipation means configured to direct heat generated by the light source in use towards the lens 2. A lamp assembly as claimed in Claim 1, wherein the heat dissipation means comprises a heat sink in contact with the light source and a fan directing air over or through the heat sink.3. A lamp assembly as claimed in Claim 1 or claim 2, wherein the heat dissipation means comprises a heat pipe.4. A lamp assembly as claimed in Claim 2, wherein the light source is mounted on a printed circuit board, PCB, and one end of the heat pipe is in communication with the PCB and the other end of the heat pipe is in communication with the lens.5. A lamp assembly as claimed in Claim 1 or claim 2, wherein the heat dissipation means comprises an air duct and one end of the air duct is in proximity to the light source and the other end of the air duct is in proximity to the lens.6. A lamp assembly as claimed in Claim 5 when dependent on claim 2, wherein the light source is mounted on a printed circuit board, the printed circuit board being in thermai communication with the heatsink, the fan being configured to direct a flow of air across the heatsink and into or out of the end of the air duct that is in proximity to the light source.7. A lamp assembly as claimed in any preceding claim, wherein the light source is in communication with a control system and configured to receive control signals for controlling the operation of the light source.8. A lamp assembly as claimed in Claim 7, wherein the light source is configured to operate at a first current level in normal operation and is further configured to operate at a higher current level in response to a heating control signal from the control system.9. A lamp assembly as claimed in any of Claims 4 or 6 or claim 7 or 8 when dependent on claim 4 or 6, wherein the printed circuit board comprises a heating trace line, the printed circuit board being configured to send current through the heating trace line in response to a heating control signal from the control system, optionally wherein the heating trace line comprises a resistor.10. A lamp assembly as claimed n any preceding claim wherein the lens comprises heat conductive eleme ts 11. A lamp assembly as claimed in Claim 10, wherein the heat conductive elements are in the form of metal pathways on a surface of the lens.12. A headlamp for a vehicle comprising the assembly of any of Claims 1 to 11.13. A lighting system for a vehicle comprising the lamp assembly of any one of Claims 1 to 11 and a control system for controlling the lamp assembly 14. A vehicle comprising the lamp assembly of any of Claims 1 toll.