DE102012215463A1 - Method for performing color balance in luminous display of vehicle components, involves operating luminous display in balanced mode, in which luminous display emits light in predetermined mixed color intermittent for limited time interval - Google Patents

Abstract

The method involves operating a luminous display (20) in a balanced mode, in which the luminous display emits light in a predetermined mixed color intermittent for a limited time interval. The light units of the luminous display emit light with same brightness or differing from group to group for generation of mixed color. The groups of the light units are activated and switched-on in sequential activation phases in the balanced mode for generation of the balanced mode-mixed colors.

Description

The invention relates to a method for performing a color balance in a luminous display, which has at least two light emitting in different colors illuminant and the light radiates in a predetermined color, which z. B. is representative of the representation of an operating state of a vehicle component and / or an operating setting for a vehicle component.

The use of colored illuminated displays for optically representing an operating state of a vehicle component or the operating setting made by an operator (default) for the vehicle component increases the ease of use. So you can z. B. by changing the color of a light indicator from blue to red or vice versa indicate in which operating mode a motor vehicle Temperierungs- or air conditioning works or should work (heating or cooling operation).

For displaying changeable mixed colors, illuminated displays are used with a plurality of (at least three differently colored) light sources (eg RGB illuminants), in particular in the form of light-emitting diodes (LEDs). The mixed colors arise by influencing the brightness of the individual bulbs, d. H. the intensities with which the lamps emit their respective light, which is achieved by a change in the current supply of the lamp. Lamps and in particular LEDs are subject to an aging process, which inevitably leads to a loss of brightness over the life of the lamp leads. Over time, therefore, the lighting means to achieve the same required brightness must be increasingly energized. Therefore, from time to time color matching is performed, which is commonly called white balance.

The object of the invention is to provide an easy to perform color (especially white) balance for a light indicator for a vehicle component.

• – die Leuchtanzeige in einem Abgleichmodus betrieben wird, in dem die Leuchtanzeige Licht intermittierend für jeweils ein begrenztes Zeitintervall, insbesondere impulsförmig, in einer vorgebbaren Mischfarbe abstrahlt, für deren Erzeugung sämtliche Leuchtmittel der Leuchtanzeige Licht mit einer für jedes Leuchtmittel einer Gruppe vorgebbaren im Wesentlichen gleichen oder gegebenenfalls von Gruppe zu Gruppe verschiedenen Helligkeit abstrahlen,
• – die Gruppen von Leuchtmitteln im Abgleichmodus zur Erzeugung der Abgleichmodus-Mischfarbe in sequentiellen Ansteuerungsphasen angesteuert und zugeschaltet werden, und
• – die Reihenfolge der Phasen der Ansteuerung und Zuschaltung der Gruppen von Leuchtmitteln für jede impulsförmige Lichtabstrahlung im Abgleichmodus insbesondere zyklisch verändert wird,
• – wobei in jedem Zyklus ein Abgleich der Helligkeit der Leuchtmittel derjenigen Gruppe erfolgt, die ihr Licht zu Beginn einer Ansteuerungsphase und damit bis zum Zuschalten der nächsten Gruppe von Leuchtmitteln alleinig abstrahlen,
• – wobei die aktuelle Helligkeit der jeweiligen zu Beginn einer Ansteuerungsphase Licht abstrahlenden Leuchtmittel mittels eines Helligkeitssensors gemessen und mit der für diese Leuchtmittel vorgegebenen Helligkeit verglichen wird und
• – wobei die Ansteuerung für jedes Leuchtmittel bei einer Helligkeitsabweichung zur Kompensation derselben angepasst wird.

To achieve this object, the invention provides a method for performing a color balance in a light display, which has at least two light emitting in different colors light source and emits the light in a predetermined color, which z. B. is representative of the representation of an operating state of a vehicle component and / or an operating setting for a vehicle component, proposed in the method

• - The light display is operated in a trim mode in which the light indicator intermittently emits light for a limited time interval, in particular pulsed, in a predetermined mixed color, for their generation all the light emitting means of the light display light with a presettable for each light source of a group substantially the same or if necessary, radiate different brightness from group to group,
• - the groups of lamps in the adjustment mode for generating the adjustment mode mixed color in sequential drive phases are driven and connected, and
• The sequence of the phases of the activation and connection of the groups of lamps for each pulse-shaped light emission in the adjustment mode is in particular cyclically changed,
• - In each cycle, an adjustment of the brightness of the lamps of that group takes place, which radiate their light at the beginning of a driving phase and thus until the next group of lamps, the sole connection,
• - Wherein the current brightness of the respective light emitting at the beginning of a driving phase light source is measured by means of a brightness sensor and compared with the predetermined brightness for these lamps, and
• - Wherein the control is adjusted for each light source at a brightness deviation to compensate for the same.

In the color balance according to the invention, the light display is operated in a balancing mode in which the light display intermittently emits their light for a limited time interval, in particular pulsed, in a predetermined mixed color, for their generation the responsible for the delivery of mixed color light illuminant of the light indicator with one emitting for each lamp of a group predetermined, substantially the same or possibly different from group to group brightness. Such a calibration mode can be carried out, for example, during a flash operation of the illuminated display, which is associated, for example, after starting the vehicle for the duration or during or during the startup of all vehicle components and in particular that component or components to which the illuminated display , is automatically activated. In principle, the adjustment mode can be carried out at the beginning or at the end of an activation of the indicator or in the meanwhile during the activation. It is also possible for the adjustment mode to be in the case of a light display that is inactive or inactive component or components assigned to the light display, for example, when the vehicle is parked, is carried out briefly.

The pulse-shaped or more generally expressed light emission for a specific time interval makes it possible to control the individual light sources or the groups of the individual light sources sequentially and temporally overlapping in order to emit light in the mixed color required for color matching (usually white balance). In this case, the light source (at least the light source of the group of light sources which is activated at the time first) is then only active in time until the next light source (or the light source of the next group to be switched on) is switched on. Within this period of time, the brightness with which the luminous means (or the luminous means of the first group) emits light can then be detected metrologically or sensory. If a deviation from the required (target) brightness is detected in this process, the current supply to the light source is readjusted (brightness adjustment). By particular cyclical change of the order in which the lighting means (or the groups of the lighting means) are driven sequentially, each light source (or the light sources of each group) can be subjected to a brightness balance.

The method according to the invention therefore starts from an asynchronous activation of the lighting means in the adjustment mode. But even moreover, the lighting means can advantageously be controlled asynchronously in order to produce the respectively required mixed color. Thus, in normal operation of the light display, the brightness control of the groups of light sources is effected by, for example, pulse width modulation, in which the fundamental frequency with which the light sources are driven differs from group to group. Here, the fundamental frequencies can each differ by at least 10% from each other. In a specific case, the fundamental frequencies for three groups of illuminants may be substantially 400 Hz for one group, substantially 500 Hz for the second group, and substantially 600 Hz for the third group.

Expediently, the illuminated display comprises the aforementioned three groups of lighting means, wherein the one group of lamps produces red light, the second group of lamps green light and the third group of lamps blue light. These RGB colors can be used to create all mixed colors. However, the bulbs may also comprise fewer or more than three groups.

The color balance in the adjustment mode is expediently carried out using white light as the adjustment mode mixed color.

The invention thus proposes to selectively change the sequence with which the differently colored illuminants or the different groups of the same color illuminants are activated, so that only one illuminant or a group of same color illuminants is driven for a certain period of time. The "first color" that is generated thus changes periodically or cyclically. Each "color" can then be subjected to a brightness balance, which can be counteracted by aging phenomena.

As light sources are particularly suitable LEDs. In principle, however, other types of lighting means, such as filament bulbs o. The like. Be used.

• – die Leuchtmittel mindestens in zwei Gruppen mit jeweils mindestens einem Leuchtmittel unterteilt werden, wobei das mindestens eine Leuchtmittel jeweils einer Gruppe Licht in einer vorgebbaren Farbe und die Leuchtmittel von Gruppe zu Gruppe Licht unterschiedlicher Farbe abstrahlen,
• – die Helligkeit, mit der die Leuchtmittel Licht abstrahlen, gesteuert wird, wobei die Helligkeitsansteuerung der Gruppen von Leuchtmitteln durch eine Pulsweitenmodulation erfolgt und die zu jeweils einer Gruppe gehörenden Leuchtmittel mit derselben Grundfrequenz und die Leuchtmittel von Gruppe zu Gruppe mit unterschiedlichen Grundfrequenzen angesteuert werden, so dass es infolge von Ansteuerungsfrequenzschwebungen wiederkehrend dazu kommt, dass die Leuchtmittel gruppenweise in unterschiedlichen Zeitintervallen leuchten, wobei die jeweilige Gruppe von allein leuchtenden Leuchtmitteln oder das jeweils allein leuchtende Leuchtmittel zyklisch wechselt,
• – die aktuelle Helligkeit der allein leuchtenden Leuchtmittel mittels eines Helligkeitssensors gemessen und mit der für diese Leuchtmittel vorgegebenen Helligkeit verglichen wird und die Ansteuerung für jedes Leuchtmittel bei einer Helligkeitsabweichung zur Kompensation derselben angepasst wird.

According to a further aspect of the invention, the above object is achieved by a method for performing a color balance in a luminous display, which has at least two light emitting in different colors and the light emits in a predetermined color, wherein the method

• The luminous means are subdivided into at least two groups each having at least one luminous means, the at least one luminous means radiating light of a predefinable color in each case of one group and the illuminants emitting light of different color from group to group,
• The brightness with which the light emitting means emit light is controlled, wherein the brightness control of the groups of light sources is effected by a pulse width modulation and the light sources belonging to one group are driven at the same fundamental frequency and the light sources are driven from group to group with different fundamental frequencies that as a result of control frequency beats, there is a recurring effect that the lighting means illuminate in groups at different time intervals, wherein the respective group cyclically changes from solely illuminating light sources or the respectively illuminating illuminant,
• - The current brightness of the only illuminating means of light is measured by means of a brightness sensor and compared with the predetermined brightness for these bulbs and the control for each light source is adjusted at a brightness deviation to compensate for the same.

In this variant of the invention, the individual groups of LEDs are brightness-controlled, by each pulse width modulation (PWM) with different (repeat) Frequencies. This leads to a so-called frequency beating. Beating is the result of the additive superposition of two oscillations, which differ only slightly in their frequency. In other words, there are thus time-recurring states in which the LEDs of each one of the groups are activated and activated. In these intervals, a brightness measurement of these LEDs can then be carried out and the LEDs are checked accordingly and readjusted, if necessary. The frequency beating is not visually significant, so goes unnoticed by the viewer. It can be provided with advantage that the different frequencies of the PWM controls of the LEDs can vary, ie the resulting beats vary, making these states even less visually appear.

The second variant of the invention described above can take place during the normal operation of the illuminated display or else in a (separate) calibration mode.

The invention will be explained in more detail with reference to an embodiment with reference to the drawing. In detail, they show:

1 schematically a block diagram for the inventive control of three different color bulbs with color balance (brightness balance of the individual bulbs) and

2 three timing diagrams to illustrate the changing sequences with which the three bulbs are driven in the adjustment mode.

1 schematically shows a drive unit 10 for a color or white balance of several in this embodiment each embodied as LEDs bulbs, the one or more red LEDs 12 , one or more green LEDs 14 and one or more blue LEDs 16 include. In the 1 represented individual LEDs 12 . 14 and 16 are therefore representative of a first group of red LEDs 12 , a second group of green LEDs 14 and a third group of blue LEDs 16 , The brightness of each of these LEDs or each set of three LEDs 12 . 14 respectively. 16 is using a brightness sensor 18 determined.

While the drive unit 10 During normal operation of the LEDs they are energized accordingly, so that a desired mixed light is set, the drive unit 10 in a trim mode, sequentially drive each set of LEDs, as shown in the timing diagrams of FIGS 2 is clarified. In a first drive interval T ₁ , at time t _{1,1, the} first red LED 12 until then at a time t _1.2, the green LED 14 is controlled. Within the interval T _{A, 1} between the times t _1,1 and t _1,2 so lit exclusively the red LED 12 whose brightness with the help of the brightness sensor 18 is determined. If the brightness deviates from a setpoint value, the current supply to the red LED becomes 12 readjusted. Following on at the time t _{1.2 takes} place connection of the green LED 14 Then at time t _1.3, the blue LED 16 switched on. Overall, this results after passing through the Absteuerungssequenz a short-term light emission through all three LEDs in a provided for color matching mixed color, which may be white, for example. Subsequently, all the LEDs are turned off, and then activated again sequentially after a certain time, but in a different order than the previous time. According to 2 Namely, at time t _2.1 , the green LED will first be illuminated 14 controlled for the interval T _{A, 2} until the time t _2,2 , to which the blue LED 16 is switched on, only lit. In this interval you can now adjust the brightness of the green LED 14 be made. At the time t is _2.3 then the red LED 12 switched on.

In a further interval T ₃ then at the beginning (time t _3.1 ), the blue LED 16 activated as the first LED, until then at time t _3.2, the second LED, in this case, the red LED 12 is switched on. Within the time interval T _{A, 3} between the times t _3.1 and t _3.2 then lit exclusively the blue LED 16 , which can be subjected to a brightness balance in this interval. As a result, in addition to the red LED 12 also the green LED 14 activated, namely at time t _3.3 .

The process described above can be performed several times; Ideally, however, a calibration mode that extends over a period in which the sequence in which the differently colored LEDs are driven is once cyclically reversed is sufficient.

In the remaining time, in which the LEDs of different color comprehensive light indicator 20 is operated, the brightnesses of the individual LEDs can be controlled, for example by pulse width modulation, to deliver the desired mixed color. In this case, it is advantageous if the fundamental frequencies at which the LEDs of different colors are operated deviate from one another, namely by at least 10%.

LIST OF REFERENCE NUMBERS

10

control unit

12

red LED

14

green LED

16

blue LED

18

brightness sensor

20

light display

T _{A, 1}

Time interval for the brightness adjustment for the LED 12

T _{A, 2}

Time interval for the brightness adjustment for the LED 14

T _{A, 3}

Time interval for the brightness adjustment for the LED 16

Claims (8)

A method for performing a color balance in a light display, which has at least two light emitting in different colors light source and the light emits in a predetermined color, which z. B. representative of the representation of an operating state of a vehicle component and / or an operating setting for a vehicle component, wherein in the method - the indicator ( 20 ) is operated in a calibration mode in which the indicator ( 20 ) Emits light intermittently for a limited time interval, in particular pulse-shaped, in a predefinable mixed color, for the generation of which all illuminants ( 12 . 14 . 16 ) of the illuminated display ( 20 ) Light with one for each light source ( 12 . 14 . 16 ) radiate a group of predeterminable essentially the same or, where appropriate, group-to-group brightness, the groups of illuminants ( 12 . 14 . 16 ) in the adjustment mode for generating the adjustment mode mixed color in sequential activation phases, and - the order of the phases of the activation and connection of the groups of lamps ( 12 . 14 . 16 ) is cyclically changed in each case for each pulse-shaped light emission in the calibration mode, wherein in each cycle a comparison of the brightness of the lamps ( 12 . 14 . 16 ) of that group whose light is at the beginning of a driving phase and thus until the next group of lamps ( 12 . 14 . 16 ) radiate solely, - wherein the current brightness of the respective illuminants radiating light at the beginning of a driving phase ( 12 . 14 . 16 ) by means of a brightness sensor ( 18 ) and with the for these lamps ( 12 . 14 . 16 ) predetermined brightness is compared and - wherein the control for each bulb ( 12 . 14 . 16 ) is adjusted at a brightness deviation to compensate for the same. Method for carrying out a color balance in a light-emitting display, which has at least two light sources radiating in different colors and which emits light in a predefinable color, wherein in the method - the light sources ( 12 . 14 . 16 ) at least in two groups, each with at least one lamp ( 12 . 14 . 16 ), wherein the at least one light source ( 12 . 14 . 16 ) each of a group of light in a predefinable color and the bulbs ( 12 . 14 . 16 ) emit light of different colors from group to group, - the brightness with which the illuminants ( 12 . 14 . 16 ) Radiate light, is controlled, wherein the brightness control of the groups of light sources ( 12 . 14 . 16 ) is carried out by a pulse width modulation and belonging to each group of lamps ( 12 . 14 . 16 ) with the same fundamental frequency and the illuminants ( 12 . 14 . 16 ) are driven from group to group with different fundamental frequencies, so that, as a result of activation frequency beats, the lighting means ( 12 . 14 . 16 ) shine in groups at different time intervals, the respective group of illuminating illuminants ( 12 . 14 . 16 ) or the only illuminating illuminant ( 12 . 14 . 16 ) cyclically changes, - the current brightness of the illuminating illuminants ( 12 . 14 . 16 ) by means of a brightness sensor ( 18 ) and with the for these lamps ( 12 . 14 . 16 ) predetermined brightness and the control for each bulb ( 12 . 14 . 16 ) is adjusted at a brightness deviation to compensate for the same. Method according to Claim 1 or 2, characterized in that the illuminated display ( 20 ) three groups of bulbs, namely red, green and blue bulbs ( 12 . 14 . 16 ) having. A method according to claim 1 optionally together with claim 3, characterized in that the color balance in the adjustment mode based on white light as adjustment mode mixed color. Method according to Claim 1, if appropriate together with Claim 3 or 4, characterized in that the brightness control of the groups of light sources ( 12 . 14 . 16 ) is carried out by a pulse width modulation, wherein the lamps belonging to each group ( 12 . 14 . 16 ) with the same fundamental frequency and the illuminants ( 12 . 14 . 16 ) are controlled from group to group with different fundamental frequencies. A method according to claim 2 or 4, characterized in that the fundamental frequencies differ by at least 10% from each other. Method according to Claim 6, characterized in that the fundamental frequencies for the three groups of light sources ( 12 . 14 . 16 ) are substantially 400 Hz, substantially 500 Hz and substantially 600 Hz. Method according to one of claims 1 to 7, characterized in that the lighting means LEDs ( 12 . 14 . 16 ) exhibit.

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