Abstract
A light fixture system comprising a light fixture comprising light sources arranged in groups, wherein each group comprises one or more light sources, and a controller, wherein the controller is arranged to control the groups so that each of the groups is repeatedly switched on and off, wherein at a first point in time some groups are switched on and others are switched off, at a second point in time some of the groups which were switched on at the first point in time are switched off, and some of the groups which were switched off at the first point in time is switched on, and at a third point in time some of the groups which were switched on at the second point in time are switched off, and some of the groups which were switched off at the second point in time are switched on.
Claims
1. A light fixture system comprising: a light fixture comprising: a plurality of light sources arranged in a plurality of groups, wherein each group comprises one or more light sources, and a controller, wherein according to at least one setting of the light fixture, the controller is arranged to control the plurality of groups so that each of the groups is repeatedly switched on and off, wherein: at a first point in time, one or more groups are switched on, and other one or more groups are switched off, at a second point in time, one or more of the groups which were switched on at the first point in time are switched off, and one or more of the groups which were switched off at the first point in time are switched on, and at a third point in time, one or more of the groups which were switched on at the second point in time are switched off, and one or more of the groups which were switched off at the second point in time are switched on, and wherein a period of time between the first point in time and the third point in time is equal to or less than 1/10 s.
2. The light fixture system of claim 1, wherein a period of time between the first point in time and the third point in time is equal to or less than 1/50 s.
3. The light fixture system of claim 1, wherein each of the one or more groups which are switched on at the first point in time, the one or more groups which are switched on at the second point in time, and the one or more groups which are switched on at the third point in time, is unique.
4. The light fixture system of claim 1, wherein a moving average of an intensity of one or more of the groups is substantially constant within a period of time spanning 10 seconds or more, wherein the moving average is based on a sample period equal to or less than 1 second.
5. The light fixture system of claim 1, wherein a moving average of a total intensity of all of the groups is substantially constant within a period of time spanning 10 seconds or more, wherein the moving average is based on a sample period equal to or less than 1 second.
6. The light fixture system of claim 1, wherein according to the at least one setting, one or more of the groups which are switched on during at least one of the first point in time, the second point in time, or the third point in time, have a variable intensity, and are switched on at an intensity being less than 50% of a maximum intensity.
7. The light fixture system of claim 1, wherein according to the at least one setting, one or more of the groups which are switched on during at least one of the first point in time, the second point in time, or the third point in time, have a variable intensity, and are switched on at an intensity being a minimum intensity.
8. The light fixture system of claim 1, wherein according to the at least one setting, at any time, at least one group is switched off.
9. The light fixture system of claim 1, wherein according to the at least one setting, multiple groups within the plurality of groups are each controlled according to a periodic scheme.
10. The light fixture system of claim 9, wherein groups within the plurality of groups, which are each controlled according to a periodic scheme, are out-of-phase with each other.
11. The light fixture system of claim 9, wherein groups within the plurality of groups, which are each controlled according to a periodic scheme, are having periods of a same length.
12. The light fixture system of claim 9, wherein groups within the plurality of groups, which are each controlled according to a periodic scheme, are having identical functions with respect to each other.
13. The light fixture system of claim 1, wherein an intensity of each group of light sources is controlled via pulse-width modulation.
14. The light fixture system of claim 13, wherein according to the at least one setting a total intensity of the plurality of groups is substantially constant across regular intervals of the pulse width modulation.
15. The light fixture system of claim 1, wherein each group of light sources is individually controlled via a dedicated pulse-width modulation control or via dedicated switches in combination with a general pulse-width modulation control, for controlling a pulsewidth of each group in the plurality of groups.
16. The light fixture system of claim 1, wherein the light fixture is a moving head.
17. The light fixture system of claim 1, wherein the plurality of light sources are capable of delivering in total at least 5 klm.
18. The light fixture system of claim 1, wherein a luminance of each light source of the plurality of light sources is above 250 lm/mm.sup.2.
19. A controller for controlling a light fixture, wherein said light fixture comprises: a plurality of light sources arranged in a plurality of groups, wherein each group comprises one or more light sources, wherein according to at least one setting of the light fixture, the controller is arranged to control the plurality of groups so that each of the groups is repeatedly switched on and off, wherein at a first point in time, one or more groups are switched on, and other one or more groups are switched off, at a second point in time, one or more of the groups which were switched on at the first point in time are switched off, and one or more of the groups which were switched off at the first point in time are switched on, and at a third point in time, one or more of the groups which were switched on at the second point in time are switched off, and one or more of the groups which were switched off at the second point in time are switched on, and wherein a period of time between the first point in time and the third point in time is equal to or less than 1/10 s.
20. A method of operating a light fixture, wherein said light fixture comprises: a plurality of light sources arranged in a plurality of groups, wherein each group comprises one or more light sources, said method comprising controlling the plurality of groups so that each of the groups is repeatedly switched on and off, wherein at a first point in time, one or more groups are switched on, and other one or more groups are switched off, at a second point in time, one or more of the groups which were switched on at the first point in time are switched off, and one or more of the groups which were switched off at the first point in time are switched on, and at a third point in time, one or more of the groups which were switched on at the second point in time are switched off, and one or more of the groups which were switched off at the second point in time are switched on, and wherein a period of time between the first point in time and the third point in time is equal to or less than 1/10 s.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0084] The various aspects according to the disclosure will now be described in more detail with regard to the accompanying figures. The figures show one way of implementing the present disclosure and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.
[0085] FIGS. 1 and 2 show schematics of light fixtures;
[0086] FIGS. 3 and 4 illustrate schemes for controlling groups via PWM;
[0087] FIGS. 5 and 6 show additional schematics of light fixtures;
[0088] FIG. 7 illustrates an additional scheme for controlling groups via PWM;
[0089] FIG. 8 shows an additional schematic for a light fixture;
[0090] FIGS. 9 and 10 illustrate additional schemes for controlling groups via PWM;
[0091] FIG. 11 illustrates a structural diagram of an illumination device; and
[0092] FIG. 12 illustrates a structural diagram of a moving head light fixture.
DETAILED DESCRIPTION
[0093] FIG. 1 shows a schematic of a light fixture LF comprising a plurality of groups of light sources, and more particularly a first group Gr1, a second group G2, and a third group Gr3. A grouping of light sources into separate groups may be carried out as described in U.S. Pat. No. 9,933,137B2, which is hereby incorporated by reference in entirety, and may in particular be carried out as described in FIG. 7C of U.S. Pat. No. 9,933,137 B2. In FIG. 1 all groups are switched off (thus no fill in the circles representing the groups).
[0094] FIG. 2 shows the same light fixture LF as in FIG. 1, but in FIG. 2 all light sources are switched on (thus the black fillin the circles representing of the groups).
[0095] FIG. 3 illustrates a scheme for controlling the groups via PWM, wherein in each of the regular PWM periods P1, P2, P3 and P4, each group is at maximum intensity, i.e., the duty cycle within each period is 100% for each group (where the duty cycle is discretized into four options, as indicated with the four rectangles for each group in each period). The scheme in FIG. 3 corresponds to the light fixture in FIG. 2.
[0096] In each of the illustrations of schemes for controlling the groups via PWM, such as in FIGS. 3, 4, 7 and 9, the horizontal axis denotes time t and the vertical axis indicated intensity Int. and furthermore indicates/separates the (spatially separated) groups Gr1, Gr2, Gr3.
[0097] FIG. 4 illustrates a scheme for controlling the groups via PWM for achieving the minimum intensity achievable with the minimum pulse width in each regular PWM period, wherein in each of the regular PWM periods P1, P2, P3 and P4, each group is at minimum (non-zero) intensity, i.e., the duty cycle within each period is 25% for each group. The scheme in FIG. 4 corresponds to the light fixture in FIG. 5.
[0098] FIG. 5 shows the same light fixture LF as in FIGS. 1-2, but in FIG. 5 all light sources are switched on at minimum intensity (thus the dark grey pattern in the circles representing of the groups).
[0099] FIG. 6 shows the same light fixture LF as in FIGS. 1, 2 and 5, but in FIG. 6 only group Gr1 is switched on and it is switched on at minimum intensity (thus the dark grey pattern in the circle representing that group Gr1). The spatially averaged intensity is thus merely one third of the (“nominal”) minimum intensity as depicted in FIGS. 4-5, but the light fixture is not homogeneously illuminated, which inhomogeneity may be observable by an observer, such as a human observer, e.g., by looking directly into or at the light fixture, at the resulting light (mid-air) or at an object, such as a surface, upon which the light is incident.
[0100] FIG. 7 illustrates a scheme for controlling the groups via PWM for achieving the spatially averaged sub-minimum intensity depicted in FIG. 6, wherein in each of the regular PWM periods P1, P2, P3 and P4, the first group Gr1 is at minimum (non-zero) intensity, i.e., the duty cycle within each period is 25%, and the other groups Gr2, Gr3 are switched completely off in each period.
[0101] FIG. 8 shows the same light fixture LF as in FIGS. 1, 2, 5, and 6, but in FIG. 8 all groups Gr1, Gr2, Gr3 are controlled according to a scheme (illustrated in FIG. 9) according to which each group Gr1 is repeatedly switched on and off so as to have a time averaged intensity being less than the minimum intensity of, e.g., the first group Gr1 in FIGS. 6-7 (thus the light grey pattern in the circles representing each group). Thus, while a “sub-minimum” intensity is achieved, the light fixture remains homogeneously illuminated as observable by an observer, such as a human observer, e.g., by looking directly into or at the light fixture, at the resulting light (mid-air) or at an object, such as a surface, upon which the light is incident.
[0102] FIG. 9 illustrates a scheme for controlling the groups via PWM for achieving the homogeneous sub-minimum intensity depicted in FIG. 8 wherein each of the groups is repeatedly switched on and off, and wherein
[0103] 1. at a first point t1 in time, [0104] i. the first group Gr1 and the third group Gr3 are switched on, and [0105] ii. the second group Gr2 is switched off,
[0106] 2. at a second point in time, [0107] i. the first group Gr1 and the third group Gr3 are switched off, and [0108] ii. the second group Gr2 is switched on, and
[0109] 3. at a third point in time, [0110] i. the first group Gr1 and the third group Gr3 are switched on, and [0111] ii. the second group Gr2 is switched off,
[0112] wherein a period of time between the first point in time and the third point in time is equal to or less than 1/10 s, thus in each of the regular PWM periods P1, P2, P3 and P4, and at each of the time points t1, t2, t3, at least one group is switched off and each group is at a time averaged intensity being sub-minimum, i.e., the duty cycle within each period is on average less than 25%. However, to an observer, such a human observer, the light fixture appears homogeneously and constantly lit at the sub-minimum intensity.
[0113] FIG. 10 illustrates a scheme for controlling the groups via PWM for achieving a homogeneous sub-minimum intensity similar to, albeit slightly brighter (i.e., having higher intensity) than depicted in FIG. 8 (or resulting from the scheme in FIG. 9) wherein each of the groups is repeatedly switched on and off, and wherein
[0114] 1. at a first point t1 in time, [0115] i. the first group Gr1 and the third group Gr3 are switched on, and [0116] ii. the second group Gr2 is switched off,
[0117] 2. at a second point in time, [0118] i. the first group Gr1 and the second group Gr2 (which second group Gr2 was switched off at the first point t1 in time) are switched on, and [0119] ii. the third group Gr3 (which was switched on at the first point t1 in time) is switched off,
[0120] 3. at a third point in time, [0121] i. the second group Gr2 and the third group Gr3 (which third group Gr3 was switched off at the second point t2 in time) are switched on, and [0122] ii. the first group Gr1 (which was switched on at the second point t2 in time) is switched off, and
[0123] 4. at a fourth point in time, [0124] i. the first group Gr1 (which first group Gr1 was switched off at the third point t3 in time) and the third group Gr3 are switched on, and [0125] ii. the second group Gr2 (which was switched on at the third point t3 in time) is switched off, and
[0126] wherein a period of time between the first point in time and the third point in time and/or between the second point in time and the fourth point in time is equal to or less than 1/10 s, thus in each of the regular PWM periods P1, P2, P3 and P4, and at each of the time points t1, t2, t3, at least one group is switched off and each group is at a time averaged intensity being sub-minimum, i.e., the duty cycle within each period is on average less than 25%. However, to an observer, such a human observer, the light fixture appears homogeneously and constantly lit at the sub-minimum intensity. In the scheme according to FIG. 10, there are in all periods 1 group OFF and 2 groups ON (i.e., an output is in each and every period ⅔ of the nominal minimum intensity) and output is evenly distributed in space over any 3 consecutive periods. Each group is controlled according to a periodical function (such as a function with a function-period spanning 3 PWM-periods, with every third period being OFF and the remaining periods being ON at minimum intensity), with the periodical functions being identical to each other (and then each having a unique phase-shift, i.e., each function having a non-zero phase shift with respect to each of the other functions). It may be understood that the scheme is a repetitive scheme, such as repeating scheme-periods P1-P3, such as period P4 (with the ON-OFF pattern of groups Gr1-Gr3 being identical to the pattern of period P1) being the start of a new scheme-period. For the embodiment in FIG. 10, a total intensity of the plurality of groups is constant across regular intervals of the pulse width modulation.
[0127] FIG. 11 illustrates a structural diagram of an illumination device 200 (wherein “illumination device” and “light fixture” may be used interchangeably throughout the present application). The illumination device comprises a cooling module 201 comprising a plurality of LEDs 103 (which could in an alternative embodiment be one or more discharge bulbs), a light collector 241, an optical gate 242 and an optical projecting and zoom system 243. The cooling module is arranged in the bottom part of a lamp housing 248 of the illumination device and the other components are arranged inside the lamp housing 248. The lamp housing 248 can be provided with a number of openings 250. The light collector 241 is adapted to collect light from the LEDs 103 and to convert the collected light into a plurality of light beams 245 (dotted lines) propagating along an optical axis 247 (dash-dotted line). The light collector can be embodied as any optical means capable of collecting at least a part of the light emitted by the LEDs and convert the collected light to a light beams. In the illustrated embodiment the light collector comprises a number of lenslets each collecting light from one of the LEDs and converting the light into a corresponding light beam. However it is noticed that the light collector also can be embodied a single optical lens, a Fresnel lens, a number of TIR lenses (total reflection lenses), a number of light rods or combinations thereof. It is understood that light beams propagating along the optical axis contain rays of light propagating at an angle, e.g. an angle less that 45 degrees to the optical axis. The light collector may be configured to fill the optical the gate 242 with light from the light sources 103 so that the area, i.e. the aperture, of the gate 242 is illuminated with a uniform intensity or optimized for max output. The gate 242 is arranged along the optical axis 247. The optical projecting system 243 may be configured to collect at least a part of the light beams transmitted through the gate 242 and to image the optical gate at a distance along the optical axis. For example, the optical projecting system 243 may be configured to image the gate 242 onto some object such as a screen, e.g. a screen on a concert stage. A certain image, e.g. some opaque pattern provided on a transparent window, an open pattern in a non-transparent material, or imaging object such as GOBOs known in the field of entertainment lighting, may be contained within the gate 242 so that that the illuminated image can be imaged by the optical projecting system. Accordingly, the illumination device 200 may be used for entertainment lighting. In the illustrated embodiment the light is directed along the optical axis 247 by the light collector 241 and passes through a number of light effects before exiting the illumination device through a front lens 243a. The light effects can for instance be any light effects known in the art of intelligent/entertainments lighting for instance, a CMY subtractive color mixing system 251, color filters 253, gobos 255, animation effects 257, iris effects 259, a focus lens group 243c, zoom lens group 243b, prism effect 261, framing effects (not shown), or any other light effects known in the art. The mentioned light effects only serves to illustrate the principles of an illuminating device for entertainment lighting and the person skilled in the art of entertainment lighting will be able to construct other variations with additional are less light effects. Further it is noticed that the order and positions of the light effects can be changed.
[0128] FIG. 12 illustrates a structural diagram of a moving head light fixture 302 comprising a head 200 rotatable connected to a yoke 363 where the yoke is rotatable connected to a base 365. The head is substantially identical to the illumination device shown in FIG. 2 and substantial identical features are labeled with the same reference numbers as in FIG. 11 and will not be described further. The moving head light fixture comprises pan rotating means for rotating the yoke in relation to the base, for instance by rotating a pan shaft 367 connected to the yoke and arranged in a bearing (not shown) in the base). A pan motor 369 is connected to the shaft 367 through a pan belt 371 and is configured to rotate the shaft and yoke in relation to the base through the pan belt. The moving head light fixture comprises tilt rotating means for rotating the head in relation to the yoke, for instance by rotating a tilt shaft 373 connected to the head and arranged in a bearing (not shown) in the yoke). A tilt motor 375 is connected to the tilt shaft 373 through a tilt belt 377 and is configured to rotate the shaft and head in relation to the yoke through the tilt belt. The skilled person will realize that the pan and tilt rotation means can be constructed in many different ways using mechanical components such as motors, shafts, gears, cables, chains, transmission systems, bearings etc. Alternatively it is noticed that it also is possible to arrange the pan motor in the base and/or arrange the tilt motor in the head. The space 379 between the yoke and the bottom part of the head is limited as the moving head light fixture is designed to be as small as possible. As known in the prior art the moving head light fixture receives electrical power 381 from an external power supply (not shown). The electrical power is received by an internal power supply 383 which adapts and distributes electrical power through internal power lines (not shown) to the subsystems of the moving head. The internal power system can be constructed in many different ways for instance by connecting all subsystems to the same power line. The skilled person will however realize that some of the subsystems in the moving head need different kind of power and that a ground line also can be used. The light source will for instance in most applications need a different kind of power than step motors and driver circuits. The light fixture comprises also a controller 385 which controls the components (other subsystems) in the light fixture based on an input signal 387 indicative light effect parameters, position parameters and other parameters related to the moving head lighting fixture. The controller receives the input signal from a light controller (not shown) as known in the art of intelligent and entertainment lighting for instance by using a standard protocol like DMX, ArtNET, RDM etc. Typically the light effect parameter is indicative of at least one light effect parameter related to the different light effects in the light system. The controller 385 is adapted to send commands and instructions to the different subsystems of the moving head through internal communication lines (not shown). The internal communication system can be based on a various type of communications networks/systems. The moving head can also comprise user input means enabling a user to interact directly with the moving head instead of using a light controller to communicate with the moving head. The user input means 389 can for instance be bottoms, joysticks, touch pads, keyboard, mouse etc. The user input means can also be supported by a display 391 enabling the user to interact with the moving head through a menu system shown on the display using the user input means. The display device and user input means can in one embodiment also be integrated as a touch screen.
[0129] Although the present disclosure has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present disclosure is set out by the accompanying claim set. In the context of the claims, the terms “comprising” or “comprises” do not exclude other possible elements or steps. Also, the mentioning of references such as “a” or “an” etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the disclosure. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.
