WO2013149887A1

WO2013149887A1 - Light sensor for an illumination device, an illumination system comprising at least one light sensor and a method for adjusting brightness of an illumination system comprising at least one light sensor

Info

Publication number: WO2013149887A1
Application number: PCT/EP2013/056405
Authority: WO
Inventors: Axel Pilz; Lars Bornemann
Original assignee: Osram Gmbh
Priority date: 2012-04-03
Filing date: 2013-03-26
Publication date: 2013-10-10
Also published as: DE102012205475A1

Abstract

The invention relates to a light sensor (101) for an illumination device (113), an illumination system comprising at least one light sensor (101) and a method for adjusting brightness of an illumination system comprising at least one light sensor (101). These enable the light sensor (101) to be adapted to a distance (115) from a remote floor or another remote region (114) to be illuminated, including, in particular, hall floors with ceilings greater than 5m in height.

Description

description

Light sensor for a lighting device, a

Lighting system comprising at least one light sensor and a method for adjusting a brightness of a lighting system comprising at least one light sensor

The invention relates to a light sensor for a

Lighting device, a lighting system comprising at least one light sensor and a method for

Adjusting a brightness of a lighting system comprising at least one light sensor.

In lighting systems with daylight-dependent control light sensors are used, which measure light, the light is composed of artificial and natural light and is reflected by a reference surface. In this case, the resulting luminance is detected by the light sensor and a proportion of artificial lighting illumination regulated so that the luminance remains as constant as possible.

To keep a control deviation low, a

Light sensor selected in each case

Luminance range provides sufficient resolution and does not saturate. As a rule, outputted analog values of a photosensitive element, e.g. a photo-transistor or a photo-diode or a

Photoresistor, digitized via an analog / digital converter (A / D converter) and fed to an evaluation unit. If a large luminance range is to be covered, a correspondingly high-resolution A / D converter is required. In general, the A / D converter is part of a periphery of a microprocessor, which serves as an evaluation unit.

Standard microprocessors are cost-limited A / D converters with a limited and thus often low

Resolution ready. Therefore, the adjustment of the

Work area of the light sensor by a corresponding Dimensioning of an amplifier circuit on the

Analog side. The light sensors are factory-optimized for a specific work area. Because of a

Sensor measured luminance square with one

Mounting height of the light sensor relative to a lighted and monitored reference surface decreases and very much depends on the remission rate of the reference surface, a light sensor that has been developed for normal room heights of 3 m to 4 m ceiling height, e.g. not used in halls with beam heights of 10 m and more. Of the

Remission degree corresponds to a ratio of the remitted luminance of the reference surface compared to a pure white surface. This has the disadvantage that warehouses but ceiling heights of sometimes significantly more than 4 m have. However, the existing light sensors are not suitable for use in rooms with a distance to an illuminated area or an illuminated area of more than 4 m. Another problem arises when a floor is light gray, for example, but has different and possibly changing colors and textures, which can happen, for example, when a shelf is filled or emptied. Different reflections lead to different evaluations of a sensor. Regulations that are used in known light sensors for offices, are also not suitable for such scenarios, as they occur in particular in warehouses. The object of the invention is to avoid the above-mentioned disadvantages and in particular a light sensor for a lighting device, a

Lighting system comprising at least one such

Light sensor and a method for setting a

Brightness of a lighting system comprising at least one light sensor indicate, which is an insert of the

Light sensor at a greater distance from a lighted Allow surface while doing a reliable

Allow light control.

This object is achieved according to the features of the independent claims. Further developments of the invention will become apparent from the dependent claims.

To solve the problem, a light sensor for a

Lighting device proposed, the

Sensitivity of the light sensor in dependence on local conditions of the light sensor is adjustable.

Thus, a light sensor with adjustable working range is provided. It is therefore not necessary to adapt a light sensor for different work areas and to configure individually in advance. Instead, such a trained light sensor can be used, wherein at the specific application area a

Adjustment at the light sensor itself on site

can be made.

A lighting device can in particular be formed from a single light source and a single light sensor. But they can also be realized

Lighting devices with one or more

Light sensors in conjunction with one or more

Lamps or lamps to illuminate a room or a surface. The light sensor or the light sensors serve to suit the light source or lamps

to control, so that they deliver the required luminous flux. The local conditions of the light sensor are to be understood as meaning, in particular, a relation of the light sensor to an illuminated area or an illuminated area, the illumination of which can be adjusted or regulated via a signal output by the light sensor. The local conditions in this case relate in particular to a distance of the light sensor and, where appropriate, of Illuminants of the illumination device to a surface which reflects light in the direction of the light sensor.

A development is that the light sensor is equipped with an amplifier, the sensitivity of the amplifier depending on the local conditions is adjustable.

For example, if a photosensitive element of the light sensor is a very low and conventional one

Applications to low signal levels or current or

Voltage level outputs, this can thus by a

appropriate adjustment of the sensitivity of the

Amplifier be compensated. The amplifier provides e.g. at its output a signal ready, an adaptation of the

Light sensor to its local conditions

considered .

Another development is that the sensitivity of the amplifier by means of an active measurement of a

Reflection is determinable or changed.

An embodiment for active measurement consists e.g. in that the light sensor has an active measuring device by means of which the reflection can be determined. In particular, according to a development of such an embodiment, the active measuring device waves in non-visible

Spectral range and / or waves in the visible

Emission and detection of the spectral range for the determination of the reflection. Such embodiments allow

in particular also an automated adjustment of the

Light sensor itself to its current local

Conditions. In particular, it is a continuing education that the

Sensitivity of the amplifier by means of a

Input means can be specified. For example, the sensitivity of the amplifier can be adjusted using a variable resistor (potentiometer). Such a configuration allows manual adjustment and allows a simple

Structure compared to automatically detecting the ambient conditions sensing arrangements.

Also, it is a continuing education that the local

Conditions include a remission degree, a room height and / or a mounting height of the light sensor.

The light sensor is therefore also in particular

A variety of storage and manufacturing halls in a simple manner mountable, since the light sensor allows adaptation to the individual conditions of the environment. It is therefore not necessary to procure and install previously individually configured light sensors for the specific room conditions.

Furthermore, it is a development that the light sensor is adjustable by an adjustable optics.

Instead of an adjustment of an amplifier or

In addition, optical components of the

Adjusted light sensor to allow easy adjustment of the light sensor to different environmental conditions. As part of an additional training, the

Light sensor, a photosensitive element and based on the optics, a distance between a lens and the photosensitive member is adjustable.

This can be achieved, for example, by a mechanism which comprises the lens, the photosensitive element or both components adjusted relative to each other to adjust the distance between them according to local conditions.

A next development is that based on, in particular depending on the change in the distance between the lens and the photosensitive element, the sensitivity of the light sensor is adjustable.

For example, by a mechanical change of the distance, the sensitivity of the above-mentioned amplifier can also be influenced, in that by changing the distance, e.g. at the same time also an adjustable one

Resistance is changed accordingly. An embodiment is that the distance between the lens and the photosensitive element is variable based on the adjustment of the sensitivity of the light sensor. For example, manually or automatically, e.g. by means of a servomotor, the distance between lens and

be changed photosensitive element, the change depending on the setting of the

Sensitivity of the light sensor, e.g. based on a setting by the active measuring device.

The above object is also achieved by a lighting system comprising at least one such

Light sensor and at least one lamp, wherein the

Lighting is controlled depending on a signal from the light sensor.

Such a lighting system thus provides coordinated components in the form of the at least one

Light sensor and the at least one lamp ready, the components due to the thus configured

Light sensor in different rooms and halls can be used. It is therefore a very variable lighting system.

The above object is also achieved by a method for adjusting a brightness of a

Lighting system comprising at least one light sensor, wherein in the method, the sensitivity of the

Light sensor is adjusted depending on local conditions of the light sensor and wherein in the

Method is controlled at least one lamp of the lighting system according to the setting of the light sensor.

Depending on the configuration, this may be a simple control or even a complex control system. In particular, such a method may require manual adjustment steps, such as

For example, adjusting the sensitivity of the

Light sensor by a mounting person, whereupon the

Activation of at least one lamp is done automatically. Furthermore, a fully automatic system can be realized in which the sensitivity of the light sensor adjusts itself and optionally continuously

adapts to changing environmental conditions.

Uniformly allow such a light sensor for a lighting device, such a lighting system and such a method adjustment of a brightness of a lighting system of one or more lights by means of the light sensor depending on the daylight if necessary and from a distance of

Light sensor to a remote area, in particular a distant hall floor, which is to be illuminated. Different versions of a light sensor can be realized, each for different

Fields of application can be optimized. Exemplified Here are two solutions, with a first concerning an adjustment of the amplification factor. According to a second described solution, the optics of the light sensor are adapted. In particular, a combination of these solutions with each other or with even further solutions can be realized.

Embodiments of the invention are illustrated and explained below with reference to the drawings.

It shows:

Fig.l schematically components of a lighting system with a light sensor whose sensitivity is adjustable.

Fig.l shows a light sensor 101, at the base or base 102, a photosensitive element 103 is arranged. The base 102 may be, for example, a part of a housing and / or a circuit board or another receptacle for other components.

On the front side of the photosensitive element 103, the light sensor 101 has a lens 105, which may likewise be fixedly mounted on the base 102 or in a housing of the light sensor 101. Front in the lens 105th

incident light 104 is directed to a focal point 107 by the condensed lens 105 as collimated light 106. A distance 121 of the lens 105 from the photosensitive element 103 is preferably selected such that the collimated light 106 covers an active area of the photosensitive element 103 as well as possible.

A signal dependent on the incidence of light

Photosensitive member 103, in particular a current or voltage level of the photosensitive member 103 is via corresponding lines an amplifier 109th an exemplary electronics 108 supplied. The

Electronics 108 is preferably also arranged on or in the base 102 of the light sensor 101. An output signal of the amplifier 109 is passed to an evaluation unit 110, which evaluates the intensity of the light to a

To produce or provide output signal.

Based on the output signal of the light sensor 101 and the evaluation unit 110 may be an example sketched

Illuminant 111 as a light source

Lighting device 113 are controlled. from

Illuminant 111 emitted light 112 falls in the direction of the area which is monitored by the light sensor 101. From an illuminated area or an irradiated space area 114, the light 112 is reflected as the incident light 104 or as a portion thereof. If the intensity of the incident light 104 changes due to aging of the illuminant 111 or a change in environmental conditions, such as e.g. a contamination of the illuminated area, this is detected by the light sensor 101, so that the evaluation unit 110 the

Lamp operating device 123 controls accordingly.

To a mounting height 115 as exemplary local

Condition for adjusting the sensitivity of

To determine the light sensor 101, the amplifier 109 can be set appropriately. A setting of the

Amplifier 109 is done for example by means of a manually operated input means 122 in the manner of a

Potentiometer, which is arranged on the light sensor 101. Through the potentiometer, for example, the

Sensitivity of the amplifier 109 to be changed.

The required gain can also be automatic

be determined by optionally an active measuring device 116 connected to the light sensor 101 or in the

Be integrated light sensor 101. The example shown active measuring device 116 has a

Light source on, in particular in the non-visible

Spectrum waves 117 emitted in the direction of

illuminating surface 114. The waves 117 are reflected at the surface 114 and the portion of the reflection 118 which is transmitted through the lens 105 into the photosensitive

Element 103 occurs, can be evaluated by the evaluation unit 110. In particular, a differentiation and separate evaluation based on the knowledge of

Wavelength or a unique modulation frequency or a superimposed sensor-specific signal of

emitted wave 117 take place. Because of the ratio between emitted and reflected light resulting from the distance 115 and the reflectance of the surface 114, the gain optimized for the control function of the sensor can be determined.

According to a further optional embodiment, an adjustment of the light sensor 101 is also by a

Adjustment of an adjustable optics 119 feasible.

Illustrated by way of example is the photosensitive element 103 once with solid lines and once with

dashed lines. The photosensitive element 103 with solid lines is located at a further distance 121 from the lens 105 than in the dashed line position. A shift in the

photosensitive element 103 along the optical axis 120, which passes through the lens 105 causes a

Displacement of the photosensitive element 103 relative to the focal point 107. At the same time, this results in an adaptation of the photosensitive element 103 to a mounting height 115 of the light sensor 101 and the reflectance of the surface 114th

Thus, according to an exemplary embodiment, incident light 104 is focused via the converging lens 105. The photosensitive element 103 can be displaced along the optical axis 120 of the lens. This can be at the same time set the distance to the focal point 107. For high mounting heights or at low reflectance, the photosensitive element 103 is close to the

Focus. At high reflectance or low

Mounting heights 115 are the lens 105 and the

photosensitive element 103 accordingly

arranged apart from each other. About a combination of amplifier 109 and evaluation unit 110 is a

corresponding control signal issued. In an alternative embodiment, the

Amplification factor of the amplifier 109 and the position of the photosensitive member 103, e.g. about the

Set input means 122 (e.g., trim potentiometer). By a corresponding mechanical coupling, the two adjustment options can be coupled together.

According to the present solution can thus be the

Amplification factor of the analog amplifier 109 downstream of the photosensitive element 103 to the local conditions, e.g. the mounting height 115 and / or the

Remission grade, adjust.

Alternatively, this adjustment can also be made by the adjustable optical system 119 by moving the photosensitive element 103 into or out of the focal point 107 of the lens 105. This can be achieved by changing the distance 121 of the lens 105 to the photosensitive element 103.

In an alternative embodiment, the two

Mechanisms be interconnected. This can e.g.

be achieved in that the adjustment of the optics 103 simultaneously acts on a potentiometer, which in turn affects the gain of the amplifier 109. The setting can be simplified, for example, by using a knob or the like. carried out, which is provided with two meter scales. An inner meter scale is used for setting the mounting height at high Reflection factor, which corresponds to a bright reference surface, and an outer meter scale is used for setting with low reflection factor, which corresponds to a dark reference surface. The

In this case, the reference surface is in particular a section of a hall floor to be illuminated or of another area 114 spaced from the illumination device 113 and the light sensor 101. In the further developed variant, the light sensor 101 can independently determine the reflection properties by actively emitting light and measuring the reflected luminance. To differentiate from surrounding

Lighting or daylight, the actively emitted light can be modulated with a characteristic frequency. The active measurement of the reflection properties can additionally be used to prevent interference

short-term changes in the reflection properties

automatically detect and compensate, if e.g. a vehicle is parked on the reference surface.

By adjusting the amplification factor or the distance 121 to the focal point 107, a light sensor 101 can be offered, which is universal for different mounting heights or surfaces with different

Use reflective properties. Subsequent adaptation e.g. with increasing pollution of the

Reference surface is possible at any time, whereby the active measurement can be used to make this adjustment automatically.

In particular, the reflective surface 114 may be configured as a reference surface or as a reference region. LIST OF REFERENCE NUMBERS

101 light sensor

102 socket or base

103 photosensitive element

104 incident light

105 lens

106 bundled light

107 focus

108 electronics

109 amplifiers

110 evaluation unit

111 bulbs

112 light

113 lighting device

114 illuminated area or illuminated

reflective surface

115 mounting height

116 active measuring device

117 emitted waves

118 reflection

119 adjustable optics

120 optical axis

121 distance lens to photosensitive element 122 input means

123 light bulb operating device

Claims

Light sensor (101) for a lighting device (113),

- Wherein the sensitivity of the light sensor (101), depending on local conditions of the

Light sensor (101) is adjustable.

A light sensor (101) according to claim 1, comprising

Amplifier (109), where the sensitivity of the

Amplifier (109) depending on the local

Conditions is adjustable.

A light sensor (101) according to claim 2, wherein the

Sensitivity of the amplifier (109) by means of an active measurement of a reflection (118) can be determined.

Light sensor (101) according to one of claims 2 or 3, wherein the sensitivity of the amplifier (109) can be predetermined by means of an input means.

Light sensor (101) according to one of the preceding

Claims in which the local conditions

- a degree of remission,

- a room height and / or

- one mounting height (115)

of the light sensor (101).

Light sensor (101) according to one of the preceding

Claims in which the light sensor (101) is adjustable by means of an adjustable optical system (119).

A light sensor (101) according to claim 6, wherein said

Light sensor (101) has a photosensitive element (103) and on the basis of the optics (119), a distance (121) between a lens (105) and the photosensitive element (103) is adjustable. A light sensor (101) according to any one of claims 7, wherein the sensitivity of the light sensor (101) is adjustable based on the change in the distance (121) between the lens (105) and the photosensitive member (103).

The light sensor (101) according to any one of claims 7 or 8, wherein the distance (121) between the lens (105) and the photosensitive member (103) is changeable by adjusting the sensitivity of the light sensor (101).

Lighting system comprising at least one

Light sensor (101) according to one of the preceding

Claims and at least one illumination device (113), wherein the illumination device (113) is driven by a signal of the light sensor (101).

Method for setting a brightness of a

Lighting system comprising at least one

Light sensor (101),

in which the sensitivity of the light sensor (101) is set as a function of local conditions of the light sensor (101),

- In which at least one light source (111) of the

Lighting system according to the setting of the light sensor (101) is driven.