Method and device for controlling the light emission of a rear light of a vehicle

A method and device for controlling a light emission of a rear lamp of a vehicle. The rear lamp includes optical components having emission surfaces having at least three partial emission surfaces. At least a first and a second light function can be produced by the light emission of the emission surfaces. After a switchover process from the first to the second light function, the first partial emission surface, which emits light for the first light function, emits no light, the second partial emission surface, which emits light for the first light function, continues to emit light, and the third partial emission surface, which emits no light for the first light function, emits light.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method for controlling a light emission of a rear light of a vehicle, whereby the rear light comprises optical components having emitting surfaces with at least three partial emitting surfaces and whereby at least a first and a second light function can be generated via the light emission of the emitting surfaces. Further, the invention relates to a device for controlling the light emission of a rear light of a vehicle.

Description of the Background Art

A problem arises in the redesigning of vehicles that because of the desired aerodynamics and the desired design, the installation space conditions for lighting equipment, particularly for rear lights, headlights, and reflectors, are very limited dimensionally. The signal effect of a light, however, is determined by the size of the emitting surface and by the light density. Furthermore, the vehicle lighting equipment contributes greatly to the vehicle design. The design of the lighting equipment is often intended to give the vehicle a characteristic appearance that is easy to recognize. Further, the problem arises that the cost of the production of the lights is to be as low as possible.

DE 196 05 813 A1 discloses an indicator lamp array that provides signals dependent on the vehicle's operating state. In this case, additional light emitting areas, which light up at a specific braking strength, are mounted on the back of the vehicle at increasingly greater distances to the ground.

DE 100 05 499 A1 describes a device for indicating different levels of the braking force for vehicles of all types. In this case, the illuminated area is the larger, the greater the braking force.

Furthermore, WO 2009/093788 A1 discloses a brake light, which allows the driver of a following vehicle to recognize the degree of speed reduction of the preceding vehicle according to the magnitude of the braking force. Horizontal rows of light sources are turned on as the brake light as the braking force increases.

In addition, DE 10 2006 046 170 A1 describes a light unit with light sources in a matrix-like arrangement. The light surface area of the light unit can be changed in this case by the turning on and off of rows of the light source matrix.

EP 0 813 996 B1, which corresponds to U.S. Pat. No. 6,100,799, describes a method for indicating the braking strength or deceleration of a vehicle. In this case, the main illumination points of a lit area assigned to a brake light move apart as the braking strength increases.

Further, DE 198 45 679 A1 discloses a lighting system for motor vehicles with at least one brake light, whereby the brake light provides different light signals depending on the braking strength.

DE 20 12 484 A1 describes a braking device formed as a multi-stage braking system. The brake light of the braking device is divided into three chambers. First one, then two, and finally three chambers are illuminated with an increasing brightness.

Finally, DE 35 16 118 A1 describes a device for indicating braking with a plurality of brake lights, arranged next to one another. These are turned on increasingly depending on the brake actuation force exerted on a pressure sensor.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a method and a device that enable a high signal effect of a rear light of a vehicle, whereby the vehicle's installation space is optimally utilized.

The method of the invention provides in an exemplary embodiment that after a switchover process from the first to the second light function, the first partial emitting surface, which emits light for the first light function, no longer emits light, the second light emitting surface, which emits light for the first light function, continues to emit light, and the third partial emitting surface, which does not emit light for the first light function, emits light. The signal effect is advantageously increased by the method of the invention in that part of a first light function is turned off and a partial emitting surface, not illuminated during the first light function, is illuminated. As a result, on the one hand, a switchover to a second light function receives more attention subconsciously. On the other hand, an association can be created between the two light functions, because a partial emitting surface is illuminated in both light functions.

The partial emitting surfaces can be formed, for example, in the shape of lines, whereby the lines of the first and second partial emitting surfaces are perpendicular to the third partial emitting surface. As a result, a special design can be imparted to the rear light. The emitting surfaces can merge thereby. They can also be arranged separated from one another, therefore not in contact with one another. Advantageously the vehicle is then provided with a high recognition value.

Substantially horizontal light lines can be produced by the first and second partial emitting surface. Substantially, a vertical light line is then produced by the third partial emitting surface. This can, e.g., include a plurality of light sources being arranged next to one another or below one another and horizontal or vertical light lines being produced in this way. The term ‘substantially’ can convey that the light lines need not run completely horizontally or vertically. Sections of the horizontal lines can also run diagonally or vertically, and sections of the vertical lines can run diagonally or horizontally. This as well results in a high vehicle recognition value because of a unique design. The signal effect is also especially high because a change in the shape of the illuminated emitting surfaces is especially striking by a 90° change in direction. In particular at least the horizontal light lines produced by the first partial emitting surface are produced by lower emitting surfaces, arranged next to one another, and/or the vertical light line of the third partial emitting surface is produced by lower emitting surfaces, arranged below one another. A plurality of lower emitting surfaces can also be arranged, whereby at least two emitting surfaces of the plurality of emitting surfaces can form the first, second, and/or third partial emitting surface. For example, the emitting surfaces are arranged in the shape of a matrix in rows and columns. Vertical light lines can then be produced by the light emission from columns of the emitting surfaces arranged in a matrix shape and horizontal light lines from rows of the emitting surfaces arranged in a matrix shape. Advantageously, a plurality of signatures for various vehicle functions can be generated in a simple manner by any combinations of emitting surfaces.

In an embodiment of the method of the invention, the first partial emitting surface can be produced by a first set of lower emitting surfaces and the third partial emitting surface can be produced by a second set of lower emitting surfaces. In this regard, at least one lower emitting surface is a subset of the first and second set of lower emitting surfaces. This means that the first and second partial emitting surface can be produced at least partially by the same lower emitting surfaces. Lower emitting surfaces that belong to only one of the two sets are then turned on or off during the switchover process.

Three light lines can be produced by at least one part of the second partial emitting surface, whereby the three light lines can be arranged such that the at least one part of the second partial emitting surface produces a u-shaped light emission. In this regard, the orientation of the u-shape can be arbitrary. The u-shape can be open at the top, bottom, on the side, or a combination of at the top, bottom, or on the side. In this case, the u-shaped light emission enables a high vehicle recognition value.

According to an embodiment of the method of the invention, the switchover process is carried out as a function of a signal, and the intensity of the light emission by the second partial emitting surface is increased as a function of the signal, whereby the intensity of the light emission is precisely as great as the intensity of the light emission by the third partial emitting surface. This combines a possible change in the shape of the illuminated emitting surfaces with an increased intensity of the light emission. This results advantageously in an especially high signal effect.

The signal can be assigned, for example, to a vehicle deceleration caused by a braking action, whereby the first light function is a taillight function and the second light function a braking light function.

According to an embodiment of the method of the invention, the third partial emitting surface can comprise at least two lower emitting surfaces. Furthermore, the second light function can be divided into two levels as a function of the signal. When the first level is reached, the second light function is generated by the second partial emitting surface and the first lower emitting surface of the third partial emitting surface. When the second level is reached, the second light function can be generated in addition by the second lower emitting surface of the third partial emitting surface, so that the second light function is generated jointly by the second partial emitting surface and the first and second lower emitting surface of the third partial emitting surface. This has the result that the signal effect of the brake light is divided into different danger levels. Depending on the braking strength, drivers of following vehicles can assess how great the danger is due to which the braking has occurred. They can advantageously quickly assess whether the braking action is a normal braking action or emergency braking and act accordingly.

The second light function can be divided into three levels as a function of the deceleration, whereby when the third level is reached the optical components are controlled such that a pulsating light is emitted by the second partial emitting surface and by the first and second lower emitting surface of the third partial emitting surface and/or a hazard warning light function of the vehicle is turned on. It is assured in this embodiment that upon emergency braking, the brake light has an especially high signal effect.

The invention relates furthermore to a device for controlling a rear light of a vehicle, whereby the rear light comprises optical components having emitting surfaces with at least three partial emitting surfaces and whereby at least a first and a second light function can be generated by means of the light emission of the emitting surfaces. The device comprises a control device by means of which the light emission by the partial emitting surfaces can be controlled. The device is characterized in that the optical components can be controlled by means of the control device such that after a switchover process from the first to the second light function, the first partial emitting surface, which emits light for the first light function, no longer emits light, the second partial light emitting surface, which emits light for the first light function, continues to emit light, and the third partial emitting surface, which does not emit light for the first light function, emits light. The device is designed in particular to carry out the method of the invention and therefore has all the advantages of the method.

According to one embodiment of the device of the invention, the optical components comprise light emitting diodes (LEDs). In comparison with conventionally employed light sources such as, for example, incandescent lamps, LEDs have a longer lifetime and a better energy efficiency, which is reflected in reduced maintenance costs. In addition, the use of LEDs in the brake light is especially advantageous, because they respond more quickly than conventionally used light sources. The following road users are therefore alerted more quickly to a situation that requires a braking reaction.

The invention relates furthermore to a vehicle having a device of this type.

DETAILED DESCRIPTION

An exemplary embodiment of device1of the invention is described with reference toFIG. 1.

Device1of the invention comprises two rear lights2, which in turn comprise a plurality of optical components5and8. Optical components5and8comprise optical fibers5and LEDs8. LEDs8couple light into optical fibers5. The decoupling surfaces of optical fibers5function as emitting surfaces6of rear lights2. Emitting surface6is divided into three partial emitting surfaces6.1,6.2, and6.3. Optical components5are arranged furthermore so that partial emitting surfaces6.1and6.2of optical fibers5.1and5.2emit light as horizontal lines. Partial emitting surface6.3, in contrast, is arranged so that it emits light as a vertical line. Partial emitting surfaces6.1and6.2are therefore perpendicular to partial emitting surface6.3. Partial emitting surfaces6.1,6.2, and6.3further are arranged separately from one another; therefore they are not in contact.

Rear light2generates as a first light function a taillight function and as the second light function a brake light function. The taillight function in this case is generated by optical components5.1,8.1,5.2, and8.2. The brake light function is generated by optical components5.2,8.2,5.3, and8.3. The free area below partial emitting surface6.1can be occupied by other light functions. For example, a turn signal or a rear fog light can be mounted there.

Furthermore, device1comprises a signal generating device4. This is a brake pedal in the specific exemplary embodiment. When brake pedal4is actuated, a signal is generated which brings about a switchover process from a taillight function to a brake light function. Brake pedal4is connected via a control device3to rear lights2. Optical components8of rear lights2are therefore controlled by control device3as a function of the signal generated via brake pedal4.

FIG. 2shows a vehicle7with a device1of the invention from the rear view. It becomes clear here that device1of the invention allows a special design of rear light2.

FIG. 3ashows a slightly modified embodiment of rear light2. In this case, partial emitting surface6.3is again divided into two lower emitting surfaces6.4and6.5arranged separately from one another.

A first exemplary embodiment of the method of the invention is described with reference toFIGS. 3 and 4. In this regard, for the first exemplary embodiment the two lower emitting surfaces are seen as a partial emitting surface6.3. The hatching inFIGS. 3a, 3b, and 3cindicates illuminated partial emitting surfaces6. The denser hatching inFIGS. 3band 3cdenotes a greater light intensity.

At the start of process10in process step11, partial emitting surfaces6.1and6.2are illuminated as the taillight function of vehicle7, as shown inFIG. 3a.

If the driver of vehicle7steps on brake pedal4, then a signal is generated in step12. In step13, the signal generated in step12is sent to control device3, which in step14then in turn controls optical components8of rear lights2. In the case of method10, LED8.1, which couples light into optical fiber5.1, is turned off. Partial emitting surface6.1, which originally had generated a part of the taillight function, accordingly no longer emits light outwardly. At the same time, LED8.3, which couples light into optical fibers5.3, is turned on. In so doing, the intensity of LED8.3is set higher than the intensity of LEDs8.1and8.2, when they provide a taillight function. The intensity of LED8.2, which couples light into optical fiber5.2, is increased simultaneously. As a result, partial emitting surface6.2is illuminated more brightly as part of the brake light function than as part of the taillight function. The signature of rear light2in the case of an activated brake light is shown inFIG. 3bor3c.

If the driver of vehicle7removes his foot from brake pedal4, the starting light distribution ofFIG. 3ais restored and the process begins again in step11.

Method10represents the simplest variant of the method of the invention.

Another exemplary embodiment of the method of the invention will be described with reference toFIGS. 3 and 5. In this case, this involves a three-level brake light.

Step21here is equivalent to step11of method10.

In step22stepping on brake pedal4generates a signal, which is associated with the deceleration of vehicle7. In this case, two deceleration values are established at which a next brake light level is turned on. In this regard, the first level is assigned a first deceleration value, for example, the value of 3 m/s2. Level one is then active until this deceleration value is exceeded. Then level two is activated, which is likewise assigned a deceleration value that is higher than the first deceleration value, for example, the value of 6 m/s2. Level two in turn is active until the second deceleration value is exceeded. Then level three is activated. The deceleration values at which the different levels are to be activated are stored in control device3. Control device3controls the various LEDs8by means of pulse width modulation.

The deceleration of vehicle7is detected in step23. In step24control device3compares the detected deceleration value with the stored deceleration value.

In step25, control device3controls LEDs8such that LED8.1is turned off, whereas LED8.4is turned on. In this case, the intensity of LED8.4is adjusted such that it is greater than the intensity of LEDs8.1and8.2during operation of the taillight function. Furthermore, the intensity of LED8.2is increased to the value of LED8.4. The signature of rear light2in this step can be seen inFIG. 3b.

After step25, depending on the driver's behavior the method is continued either with step21or with step26.

If the braking action is only a light, short braking, i.e., the driver takes his foot again off the brake, then vehicle7no longer experiences a deceleration caused by the braking force. The taillight function from step21is restored. As a result, a driver of a following vehicle is signaled that the reason for the instituted braking action no longer exists.

If the driver of vehicle7during the braking action steps more heavily on brake pedal4, so that the deceleration value is between 3 m/s2and 6 m/s2, in step26in addition to LEDs8.2and8.4, LED8.5is turned on in the same intensity as LEDs8.2and8.4. As a result, the signal effect of the brake light is greater than at a deceleration value below 3 m/s2.

The method after step26depending on the behavior of the driver of vehicle7can continue either with step28, step21, or step27.

If the driver of vehicle7reduces the pressure on brake pedal4, therefore in fact deceleration being continued, the deceleration value declines again below 3 m/s2. In step28the same brake signature is then produced as in step25. Therefore LED8.5is turned off, so that light is no longer emitted by lower emitting surface6.5of optical fiber5.5. Therefore, as in step25the signature of the brake light is generated still only by partial emitting surface6.2and lower emitting surface6.4.

If the driver of vehicle7completely removes the pressure from brake pedal4, thus vehicle7no longer experiences any deceleration. Therefore, the taillight function from step21is restored and thus the method is started from the beginning.

Step27is begun when the driver of vehicle7steps so firmly on brake pedal4that the deceleration value rises above the value of 6 m/s2. This is the case, e.g., in an emergency braking. LEDs8.2,8.4, and8.5, which are turned on in step27, are then controlled such that they give off a pulsating light emission. A signal effect is especially great as a result. Alternatively or in addition, the flashing light function of vehicle7can be turned on.

After step27the method can continue either with step21or step29depending on the behavior of the driver of vehicle7.

Step21is started when the driver of vehicle7removes his foot from the brake pedal4and thus vehicle7experiences no further deceleration due to the braking force. The taillight function is turned on again.

Step29is started when the driver of vehicle7reduces the pressure on brake pedal4, until the deceleration value again falls below the value of 6 m/s2. The pulsating light emission of LEDs8.2,8.4, and8.5is turned off. If necessary, the hazard warning light function is also turned off. Either step28or step21now follows step29.

If the detected deceleration value even at the beginning of the braking action is above the first deceleration value, step25of method20is skipped, and the signature inFIG. 3cis activated immediately.

If an emergency braking occurs at the beginning, the detected deceleration value even at the beginning of the braking action will therefore be above the second deceleration value. Then steps25and26of method20are skipped and a pulsating light emission is activated immediately.

A method of the invention naturally can also comprise only two levels. Level three of the method can be omitted, e.g., so that no pulsating light emission is activated during emergency braking. Alternatively, step25of method20can also be omitted in general.

Alternatively, partial emitting surface6.3can also be divided into more than two lower emitting surfaces, for example, into three lower emitting surfaces. Thus, for example, in level1a middle lower emitting surface and in the second level a right and left lower emitting surface together with the second partial emitting surface can then generate the second light function.

Another embodiment of rear light2is explained with reference toFIGS. 6aand6b.

In this case, the decoupling surfaces of optical fibers5again serve as emitting surface9of rear light2.

Rear light2is formed in two parts. The first part15.1is arranged, for example, on a movable part of the rear of a vehicle, for example, a trunk lid or a tailgate, and the second part15.2on a nonmovable part, for example, directly next to the trunk lid or tailgate.

The first part15.1comprises a plurality of partial emitting surfaces9.1to9.3, which are illuminated, for example, by LEDs (not shown), as explained in the previous examples.

Partial emitting surface9.2is formed thereby such that it forms a u-shape in first part15.1and a line in part15.2. The u-shape again comprises two substantially horizontal sections, running parallel to one another, and a substantially vertical section, running slightly diagonally from bottom to top, which connects the two sections running substantially horizontal to one another. The u-shape is therefore open to the side.

Partial emitting surface9.1in both parts15.1and15.2forms a substantially horizontal broad stripe. Said stripe can be formed, for example, by a plurality of lower emitting surfaces9.1′ and9.13′ arranged above one another. Partial emitting surface9.3is formed by lower emitting surfaces9.3′ and9.13′. They form a vertical stripe.

The two parts15.1and15.2of rear light2are operated simultaneously, so that rear light2generates the signatures of rear light2as shown inFIGS. 6aand6b.

A signature of a taillight function is shown inFIG. 6a. In this case, light is emitted outwardly via partial emitting surfaces9.1and9.2. Partial emitting surface9.3is not illuminated during operation of the taillight function. Partial emitting surface9.1furthermore comprises lower emitting surfaces9.1′ and9.13′.

If the brake pedal activates a switchover process from the taillight function to the brake light function, a signature is generated, as shown inFIG. 6b. Lower emitting surfaces9.1′ of partial emitting surface9.1no longer emit any light. Lower emitting surfaces9.13′ continue to emit light, because they are also assigned to partial emitting surface9.3. Moreover, lower emitting surfaces9.3′ emit light. The light intensity of lower emitting surfaces9.13′ and partial emitting surface9.2can then be adjusted to the light intensity of the additionally connected lower emitting surfaces9.3′.

The brake light function is provided jointly by partial emitting surfaces9.2and9.3.

Another embodiment of rear light2in the case of different light functions is explained with reference toFIGS. 7ato7c.

In this case, decoupling surfaces of optical fibers5again serve as emitting surface16of rear light2.

Rear light2is made as two parts, as in the embodiment ofFIGS. 6aand 6b. The first part15.1is again arranged on a movable part of the rear of the vehicle, whereas part15.2is arranged on an unmovable part of the rear of the vehicle.

Partial emitting surfaces16.1,16.2, and16.3emit light in first part15.1and in second part15.2of rear light2.

Partial emitting surface16.2is again formed u-shaped in first part15.1and as a line in second part15.2.

A plurality of lower emitting surfaces16′ are arranged in first part15.1and second part15.2of rear light2. These are arranged in eight rows and four columns slightly offset to one another. Partial emitting surfaces16.2and16.3can then be generated by any combinations of light-emitting lower emitting surfaces16′.

In addition, two partial emitting surfaces16.4are arranged in second part15.2of rear light2. These then emit light when a rear fog light function is turned on.

FIG. 7ashows a taillight function that can be generated by rear light2. The signature of the taillight function is generated, for example, in that partial emitting surface16.2emits light. Partial emitting surface16.1is generated in that lower emitting surfaces16′ of rows three and four in both parts15.1and15.2of rear light2emit light.

The signature of the taillight accordingly in first part15.1has a u-shape, formed by partial emitting surface16.2and two horizontal light lines, which are produced by partial emitting surface16.1.

If a switchover process from the taillight function to the brake light function is brought about in response to the brake pedal, a signature is generated, as it is shown inFIG. 7b. Partial emitting surface16.2continues to emit light. In this case, the light intensity with which partial emitting surface16.2emits light can be adjusted according to the described method.

In first part15.1of rear light2, the two horizontal light lines, produced by partial emitting surface16.2, are no longer produced. Instead, partial emitting surface16.3emits light. Partial emitting surface16.3in first part15.1of rear light2includes lower emitting surfaces16′ of the first and second column from the left. Two light stripes running slightly diagonally from top to bottom are formed. Moreover, partial emitting surface16.3, as in the previous example, is produced partially by the same lower emitting surfaces16′ as partial emitting surface16.1.

In second part15.2of rear light2as well, the two horizontal light lines are no longer produced. Instead, partial emitting surface16.3emits light. Partial emitting surface16.3of second part15.2includes lower emitting surfaces16′ of only the first column from the left.

Alternatively, the signature of rear light2can also correspond to the signature shown inFIG. 7c. This signature corresponds to a combination of signatures of the taillight function and brake light function ofFIGS. 7aand 7b. The taillight function is thereby not completely turned off. Rather, the signature of the taillight function from second part15.2of rear light2, as it is shown inFIG. 7a, is retained. First part15.1of rear light2has the signature of the brake light function, as it is shown in first part15.1of rear light2inFIG. 7b. In this case, the light intensities of partial emitting surfaces16.1and16.2of the taillight function can be changed in turn.

If the rear fog light function is turned on, partial emitting surfaces16.4as well emit light. This is also shown inFIG. 7c.

In the present example, not all lower emitting surfaces16′ installed in the rear light are used for generating the signatures. These unused lower emitting surfaces16′ can be used, for example, for other light functions. Alternatively, rear light2can have lower emitting surfaces16′ in the quantity and arrangement necessary for generating the desired signatures. For the example ofFIGS. 7ato 7c, this means that the rear light has only lower emitting surfaces16′, which are involved in generating the signature of the taillight function shown inFIG. 7a, the signature of the brake light function shown inFIG. 7b, or the combination of taillight and brake light functions and the rear fog light function ofFIG. 7c.