Lighting device for a vehicle and method for controlling the same

Abstract

The invention relates to a lighting device for a vehicle, comprising a housing (4) and a light lens (6) closing an opening of the housing (4); the invention relates to a lighting device having a light source unit (1), which is arranged within a housing (4) and contains a plurality of light sources (6), for generating a predetermined light distribution (3); the lighting device has a light source unit (1), and has a control unit (7) for generating a control signal (11) by means of which the light source unit (1) can be controlled, the control signal (11) being designed such that the light source unit (1) is switched off in accordance with a switching-off specification (10), and the light source unit (1) is switched off in accordance with the switching-off specification (10). In this way, at least some of the light sources (6) of the light source unit (1) are successively switched off and / or switched off in a dimming manner within the condensation protection time (tA), so that no condensation occurs on the inner side (9) of the light lens (5).

Description

Technical Field

[0001] The present invention relates to a lighting device for a vehicle, wherein the lighting device has a shell and a light lens that closes an opening of the shell; the lighting device has a light source unit that is arranged in the shell and includes multiple light sources for generating a predetermined light distribution; and the lighting device has a control unit for generating a control signal, by means of which the light source unit can be controlled.

[0002] Furthermore, the present invention relates to a method for operating a light source unit of a lighting device. Background Art

[0003] In order to avoid unwanted condensation of optical components for vehicle lighting, it is known from EP 2 014 972 B1 to provide a Peltier element as a heating element. In this way, the temperature in the interior of the housing can be kept above the dew point of the optical component.

[0004] According to EP 3 822 536 A1, an infrared radiator is integrated into the housing of a lighting device for a vehicle in order to keep the temperature in the interior of the housing at the minimum temperature required to avoid condensation.

[0005] DE 10 2019 108 312 A1 discloses a lighting device for a vehicle, in which light sources are sequentially switched on and / or off to produce a sweeping lighting effect. The sweeping lighting effect is used to produce a signal light function. Summary of the invention

[0006] It is therefore an object of the present invention to specify a lighting device and a method for operating a light source unit in such a way that undesired condensation on the inner side of an optical component of the lighting device is avoided in a simple manner.

[0007] In order to achieve the above-mentioned task, the present invention, in combination with the preamble of claim 1, is characterized in that the control signal is constructed so that the light source unit is shut down in accordance with the shut-off regulations, whereby at least a portion of the light sources of the light source unit are shut down successively and / or dimmed within the condensation protection time so that condensation does not occur on the inner side of the optical lens.

[0008] According to the present invention, the light sources of the light source unit are turned off with a delay according to the shutdown regulations so that condensation does not occur on the inner side of the light lens. Advantageously, no additional components are required to avoid condensation. Unwanted condensation is only avoided by the light source unit being turned off with a delay. The basic idea of ​​the present invention is that the light source unit or the light sources of the light source unit intelligently reduce the lighting intensity of the light source unit within the condensation protection time (shutdown time) while forming a continuous curve or a step curve, thereby avoiding condensation on the inner side of the light lens.

[0009] According to a preferred embodiment of the present invention, the condensation protection time and / or illumination intensity reduction of the light source unit are dimensioned such that the dew point temperature of the interior air is always lower than the actual temperature of the interior air of the housing within the condensation protection time.

[0010] According to a further development of the invention, the illumination intensity of the light source unit is reduced with a delay such that the temperature on the inner side of the light optic is at least 2 K, preferably 5 K, greater than the dew point temperature of the interior air. In this way, a safety margin is provided so that condensation on the light optic can still be safely avoided in the event of sudden changes in the environment.

[0011] According to a further development of the invention, the light source unit has a plurality of light sources arranged in a matrix, so that an approximately linear reduction in the lighting intensity of the light source unit can be achieved by sequentially switching off the individual light sources. If there is a linear reduction in lighting intensity over at least two hours (minimum switch-off time), condensation on the optical lens can be safely avoided.

[0012] According to an alternative embodiment of the present invention, the reduction in the illumination intensity of the light source unit can also be achieved by dimming at least some of the plurality of light sources. Advantageously, a desired switch-off curve of the illumination intensity of the light source unit can be adjusted in a simple manner.

[0013] According to a further development of the invention, the illumination intensity reduction can extend parabolically instead of linearly, so that the predetermined condensation protection time can be reduced. Since the illumination intensity of the light source unit does not drop so strongly at the beginning of the shutdown process, the temperature level of the housing interior remains relatively high in the starting area of ​​the shutdown process. Insufficient control of the interior temperature below the temperature level that occurs after the shutdown process is completed can thus be avoided.

[0014] In order to achieve the above-mentioned task, the method according to the present invention is characterized in that at least some of the light sources of the light source unit are successively turned off and / or emit light of lower illumination intensity, so that the illumination intensity of the light source unit is continuously reduced during the shut-down process until the illumination intensity reaches a zero value at the end of the shut-down process.

[0015] The particular advantage of the present invention is that by delaying the shut-off of the light source unit, the temperature level in the housing interior can be kept at such a high value that condensation of the light lens is avoided. Advantageously, only a shut-off control of the light source unit based on empirical data needs to be specified. No additional components are required.

[0016] According to a preferred embodiment of the present invention, the light source unit is turned off during a set minimum condensation protection time while its linear illumination intensity decreases. The minimum condensation protection time is preferably 2 hours, thereby avoiding such a strong temperature drop that would result in a temperature below the dew point. Advantageously, undesirable condensation can be avoided by a linear illumination intensity decrease.

[0017] According to an alternative embodiment of the present invention, the illumination intensity of the light source unit is reduced parabolically. Advantageously, in the first switch-off section, a less drastic temperature reduction of the interior is performed compared to a linear illumination intensity reduction, thereby reducing the condensation protection time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following is a more detailed description of various embodiments of the present invention with the aid of the accompanying drawings.

[0019] Figure 1 A block diagram showing a lighting device according to the present invention,

[0020] Figure 2 A diagram showing a light source unit having a plurality of light sources which can be switched off successively and the associated reduction in the luminous intensity of the light source unit,

[0021] Figure 3 A diagram showing a light source unit having a plurality of light sources dimmed simultaneously and the associated drop in the illumination intensity of the light source unit,

[0022] Figure 4 A diagram showing a light source unit with a plurality of light sources which are dimmed simultaneously, so that a parabolic drop in the lighting intensity occurs according to the diagram, and

[0023] Figure 5 At different shutdown times (condensation protection time) Figure 2 and 3The linear decrease in lighting intensity shows the temperature change curve of the interior temperature of the housing. DETAILED DESCRIPTION

[0024] The lighting device for a vehicle comprises a light source unit 1 and an optical unit 2 which is assigned to the same light source unit and contains a lens for generating a predetermined light distribution, for example, a low beam light distribution 3. The light source unit 1 and the optical unit 2 are arranged in a housing 4 of the lighting device. The opening of the housing 4 is closed or covered by a transparent optical lens 5.

[0025] The light source unit 1 has a plurality of light sources 6 , preferably LED light sources 6 , which are arranged in a matrix shape.

[0026] An actuation unit 7 is associated with the light source unit 1 , by means of which the individual light sources 6 can be switched on and / or off or switched on and / or off in a dimmed manner.

[0027] The lighting device is designed as a high-resolution headlamp having a plurality of light sources 6 in an n×m matrix. A first primary optical system (not shown) is associated with a first portion of the light sources 6. A second primary optical system (not shown) is associated with a second portion of the light sources 6. By means of a lens of the optical unit 2, a low-beam light distribution 3 is projected when the first portion of the light sources 6 is switched on, and a high-beam light distribution (not shown) is generated when the second portion of the light sources 6 is additionally switched on.

[0028] In order to avoid unwanted condensation on the inner side 9 of the light lens 5, the control unit 7 has a switch-off program 10, by means of which a control signal 11 is generated for controlled switching off of the light source 6, for example from an on state in which the low-beam light distribution 3 is generated. The control unit 7 can, for example, have a microprocessor with a program memory in which the switch-off program 10 is stored. Alternatively, the switch-off program 10 can be contained in a microcontroller as a hard-wired program.

[0029] According to the present invention Figure 2 In a first embodiment, the low-beam light distribution system 3 is switched on and arranged in n rows Z1, Z2, ... Z n And into m columns S1, S2, ...S m The light sources 6 are sequentially turned off in rows and / or columns, so that the illumination intensity B of the light source unit 1 increases from the turn-off time t A From the start time t1 until the turn-off time t A The end time t2 is reduced in a step-like manner. In each time interval Δt, the illumination intensity is reduced by the difference ΔB according to the illumination intensity of the light source 6. This results in a step-like decrease in illumination intensity B1, which extends approximately linearly. The switch-off time t AA condensation protection time is established which ensures that no condensation forms on the inner side 9 of the optical lens 5 .

[0030] exist Figure 5 The temperature inside the housing T is shown empirically in IN About the off time t A The duration of the shutdown process is shown in FIG. 1 . In this embodiment, the shutdown time t A Set the size to three hours, so that it appears Figure 5 The temperature curve K1 in the figure. Although the temperature T IN After the shutdown starts t1, the temperature suddenly drops. However, the temperature does not reach the dew point temperature T TAU , at which the condensation process will occur. Instead, the curve K1 at the dew point temperature T TAU The temperature difference Δ t =5 K, and then oscillates above this temperature value. If the light source unit 1 is switched off suddenly, with all light sources 6 being switched off simultaneously, a curve K2 will appear, which is at the same final value T END Oscillate upward, but below the dew point temperature T TAU , resulting in condensation on the optical lens 5.

[0031] Turn-off time t A The shorter the selected value, the faster the temperature curve reaches the dew point temperature T TAU In other words, the final temperature T END Insufficient control. During the two-hour shutdown time t A In the case of a curve K3, which also does not result in a dew point temperature T TAU Insufficient control of unwanted items.

[0032] According to Figure 3 In an alternative embodiment, at least some of the light sources 6 of the light source unit 1 are simultaneously controlled with a reduced illumination intensity B, so that the illumination intensity B of the light source unit 1 is linearly reduced or decreased. Instead of a step-shaped variation curve, a linear decrease B2 of the illumination intensity B is obtained. If the switch-off time t A For at least two hours, ensure that the temperature difference curve K3 is at the dew point temperature T TAU Extends above.

[0033] According to the present invention Figure 4 In another embodiment, the light sources 6 of the light source unit 1 are also switched off successively and / or controlled at the same time with a low illumination intensity B, so that the illumination intensity B3 decreases parabolically during the switch-off time t A The start time t1 and the turn-off time t A In this way, it is avoided that Figure 5 The temperature control is insufficient, so the shutdown time t A Can be shorter overall.

[0034] Reference numerals list

[0035] 1 Light source unit

[0036] 2 Optical unit

[0037] 3 Low beam distribution

[0038] 4 Housing

[0039] 5-light lens

[0040] 6 Light Source

[0041] 7 Control unit

[0042] 8 Circuit Board

[0043] 9 Inside

[0044] 10 Shutdown Procedure / Shutdown Rules

[0045] 11 Control Signals

[0046] B. Lighting intensity

[0047] B1 Lighting intensity decreases

[0048] B2 Linear Decline

[0049] B3 Lighting Intensity

[0050] K1, K2, K3 temperature curve

[0051] T A1 Start time

[0052] t A Off time

[0053] T A2 End Time

[0054] Δ tmin , Δt temperature difference

[0055] ΔB Difference

[0056] T TAU Dew point temperature

[0057] T IN Shell internal temperature

[0058] T END Terminal Value

[0059] T S temperature

[0060] Z1, Z2, ... Z n n rows (Zeit)

[0061] S1, S2, ...S m m columns

Claims

1. A lighting device for a vehicle, the lighting device comprising a housing (4) and a light lens (6) for sealing an opening of the housing (4); the lighting device comprising a light source unit (1) arranged in the housing (4) and comprising a plurality of light sources (6) for generating a predetermined light distribution (3); and the lighting device comprising a control unit (7) for generating a control signal (11), by means of which the light source unit (1) can be controlled, characterized in that: The control signal (11) is configured to cause the light source unit (1) to be turned off according to a turn-off rule (10), whereby at least a portion of the light sources (6) of the light source unit (1) are turned off during a condensation protection time (t A ) is switched off successively and / or dimmed within the optical lens (5) so that no condensation occurs on the inner side (9) of the optical lens (5).

2. The lighting device according to claim 1, characterized in that The switch-off rule (10) is configured such that the light source (6) is switched off successively and / or dimmed during a dew protection time during which the dew point temperature (T TAU ) is less than the actual internal space temperature (T IN ).

3. The lighting device according to claim 1 or 2, characterized in that: The switch-off regulation (10) is set so that the temperature (T IN ) than the dew point temperature (T TAU ) greater, more precisely at least 2 Kelvin greater, preferably at least 4 Kelvin greater.

4. The lighting device according to any one of claims 1 to 3, characterized in that The control regulations (10) are designed so that the light sources (6) of the light source unit (1) are switched off successively.

5. The lighting device according to any one of claims 1 to 3, characterized in that: The control rules (10) are configured so that at least a portion of the light sources (6) are protected from dew during the condensation protection time (t A ) during dimming with a predetermined reduced lighting intensity (B).

6. The lighting device according to any one of claims 1 to 5, characterized in that The light source (6) can be controlled so that the illumination intensity (B) of the light source unit (1) is within the dew protection time (t A ) decreases linearly or in steps.

7. The lighting device according to claim 6, characterized in that The condensation protection time (t A ) is at least two hours.

8. The lighting device according to any one of claims 1 to 5, characterized in that The light source (6) can be controlled so that the illumination intensity (B) of the light source (6) is within the dew protection time (t A ) decreases parabolically.

9. The lighting device according to any one of claims 1 to 8, characterized in that The light source (6) is in the shut-off process (t A ) at the beginning (t1) of the control so that the low-beam light distribution (3) is generated.

10. Method for operating a light source unit (1) having a plurality of light sources (6) for a vehicle according to one of claims 1 to 9, characterized in that At least a portion of the light sources (6) of the light source unit (1) are successively turned off and / or emit light with a lower illumination intensity (B), so that during the turn-off process (t A ) during which the illumination intensity (B) of the light source unit (1) is continuously reduced until the illumination intensity (B) is at the turn-off process (t A ) reaches zero at the end time (t2).

11. The method according to claim 10, characterized in that The illumination intensity (B) of the light source unit (1) is A ) during the period of time, so that the gradient of the temperature drop on the inner side (9) of the optical lens (5) and / or in the interior space of the housing (4) is small in terms of amount, so that the temperature on the inner side (9) of the optical lens (5) and / or the temperature of the interior space of the housing (T IN ) is always less than the dew point temperature (T TAU ).

12. The method according to claim 10 or 11, characterized in that The illumination intensity (B) of the light source unit (1) is at least 2 hours during the off time (t A ) decreases linearly.

13. The method according to claim 11 or 12, characterized in that The illumination intensity (B) of the light source unit (1) is at least 1 hour during the off time (t A ) descends parabolically.

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