FLAG ACTUATION SYSTEM FOR A LIGHTING FIXTURE

Abstract

A flag actuation system for a lighting fixture is disclosed. The flag actuation system comprises an actuator, an actuator axle connected to and drivable by the actuator, and at least two flags, each flag being movable between a first position in which the flag is arranged in an optical path defined by the flag actuation system, and a second position in which the flag is arranged out of the optical path. Each flag is individually and detachably connectable to the actuator axle via a magnetic actuator connection, and each flag is retainable in the first position by means of a first magnetic retaining connection and in the second position by means of a second magnetic retaining connection.

Claims

1. A flag actuation system for a lighting fixture, the flag actuation system defining an optical path through the flag actuation system, and the flag actuation system comprising: an actuator; an actuator axle connected to and drivable by the actuator; and at least two flags, each flag being movable between a first position in which the flag is arranged in the optical path, and a second position in which the flag is arranged out of the optical path; wherein each flag is individually and detachably connectable to the actuator axle via a magnetic actuator connection, and each flag is retainable in the first position by means of a first magnetic retaining connection and in the second position by means of a second magnetic retaining connection.

2. The flag actuation system according to claim 1, wherein the magnetic actuator connection comprises an adapter part mounted fixedly on the actuator axle, the adapter part thereby moving along with the actuator axle during operation of the actuator, the adapter part having at least one magnet mounted thereon, an angular position of the actuator axle and the adapter part thereby defining angular position of the at least one magnet relative to an initial angular position.

3. The flag actuation system according to claim 2, wherein each flag has at least one actuator magnet mounted thereon, and wherein a given flag is magnetically connected to the adapter part when the adapter part is arranged in an angular position where one of the magnets of the adapter part is aligned with an actuator magnet of the flag.

4. The flag actuation system according to claim 3, wherein the magnets of the adapter part and the actuator magnets of the at least two flags are arranged with substantially identical distance to the actuator axle.

5. The flag actuation system according to claim 3, wherein a position of the actuator magnet on a first flag differs from a position of the actuator magnet on a second flag.

6. The flag actuation system according to claim 5, wherein the positions of the actuator magnets on the at least two flags determine angular positions of the adapter part wherein respective actuator magnets are aligned with a magnet of the adapter part, the positions of the actuator magnets on the at least two flags thereby defining angular positions of the adapter part where respective flags are magnetically connected to the adapter part.

7. The flag actuation system according to claim 1, further comprising a first mechanical end stop and a second mechanical end stop, wherein the flags abut the first mechanical end stop when they are in the first position, and the flags abut the second mechanical end stop when they are in the second position.

8. The flag actuation system according to claim 7, wherein the first mechanical end stop and/or the second mechanical end stop is/are at least partly made from a magnetic or magnetizable material, and wherein each flag comprises a first retaining magnet establishing a first magnetic retaining connection with the first mechanical end stop when the flag is in the first position and a second retaining magnet establishing a second magnetic retaining connection with the second mechanical end stop when the flag is in the second position.

9. The flag actuation system according to claim 8, wherein a magnetic force defined by the magnetic actuator connection is larger than a magnetic force defined by the first magnetic retaining connection and larger than a magnetic force defined by the second magnetic retaining connection.

10. The flag actuation system according to claim 1, wherein the flag actuation system comprises at least three flags.

11. The flag actuation system according to claim 1, further comprising position determining means for determining the position of the flags and/or the actuator axle.

12. A lighting fixture comprising: a base; a yoke; and a head, the head including: a light source; a gate; a zoom and focus system; an exit lens; and a flag actuation system; wherein the flag actuation system comprises: an actuator; an actuator axle connected to and drivable by the actuator; and at least two flags, each flag being movable between a first position in which the flag is arranged in an optical path through the flag actuation system, and a second position in which the flag is arranged out of the optical path; wherein each flag is individually and detachably connectable to the actuator axle via a magnetic actuator connection, and each flag is retainable in the first position by means of a first magnetic retaining connection and in the second position by means of a second magnetic retaining connection.

13. The lighting fixture according to claim 12, wherein the flag actuation system is arranged along an optical axis of the head, between the light source and the exit lens.

14. A method for controlling a flag actuation system comprising an actuator, an actuator axle connected to and drivable by the actuator, and at least two flags, each flag being movable between a first position in which the flag is arranged in an optical path through the flag actuation system, and a second position in which the flag is arranged out of the optical path, wherein each flag is individually and detachably connectable to the actuator axle via a magnetic actuator connection, and each flag is retainable in the first position by means of a first magnetic retaining connection and in the second position by means of a second magnetic retaining connection, the method comprising the steps of: selecting a combination of zero or more flags to be arranged in the optical path defined by the flag actuation system; selecting a movement pattern of the actuator axle which results in the selected combination of zero or more flags being arranged in the optical path; and operating the actuator to cause the actuator axle to move in accordance with the selected movement pattern.

15. The method according to claim 14, wherein the step of selecting the movement pattern comprises selecting the movement pattern among a set of predefined movement patterns.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The disclosure will now be described in further detail with reference to the accompanying drawings in which:

[0057] FIG. 1 is a cross sectional view of a prior art lighting fixture,

[0058] FIG. 2 is a cross sectional view of a lighting fixture according to some embodiments,

[0059] FIG. 3 is an exploded view of a flag actuation system according to a first embodiment,

[0060] FIGS. 4-12 are perspective views of the flag actuation system of FIG. 3 with the flags arranged in various positions,

[0061] FIG. 13 is a perspective view of a flag actuation system according to a second embodiment, and

[0062] FIG. 14 illustrates a method for controlling a flag actuation system according to some embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

[0063] FIG. 1 is a cross sectional view of a prior art lighting fixture 1, in the form of a moving head. The lighting fixture 1 comprises a base 2, a yoke 3 and a head 4. The head 4 includes a light source 5, in the form of a plurality of LEDs, a gate 6, a zoom and focus system 7 and an exit lens 8. Light generated by the light source 5 passes through the gate 6 and the zoom and focus system 7 and exits the head 4 via the exit lens 8, thereby defining an optical path through the head 4.

[0064] The head 4 further includes a prior art flag actuation system 9 arranged in the optical path between the gate 6 and the zoom and focus system 7. The prior art flag actuation system 9 comprises two flags 10, each being connected to a separate actuator 11, in the form of a motor. Thus, each of the flags 10 can be moved into or out of the optical path independently of movements of the other flag 10. However, this flexibility requires the presence of the two separate actuators 11, thereby adding to the manufacturing costs and the weight of the lighting fixture 1.

[0065] FIG. 2 is a cross sectional view of a lighting fixture 1 according to some embodiments. The lighting fixture 1 of FIG. 2 is identical to the prior art lighting fixture of FIG. 1, except that the prior art flag actuation system 9 has been replaced by a flag actuation system 12 according to an embodiment. The flag actuation system 12 comprises two flags 13. Each flag 13 is individually and detachably connectable to a single actuator 14 by means of a magnetic actuator connection 15. Thereby each of the flags 13 can be moved into or out of the optical path, independently of movements of the other flag 13 but by means of only one actuator 14. Thereby the flexibility of the prior art flag actuation system 9 illustrated in FIG. 1 is maintained, but the manufacturing costs and the weight of the lighting fixture 1 are reduced.

[0066] FIG. 3 is an exploded view of a flag actuation system 12 according to a first embodiment. The flag actuation system 12 comprises an aperture plate 16 defining an aperture 17. When the flag actuation system 12 is positioned in a lighting fixture, the aperture 17 is arranged in the optical path of the lighting fixture. Thereby the aperture 17 defines an optical path through the flag actuation system 12.

[0067] The flag actuation system 12 further comprises an actuator 14 and an actuator axle 18 which is connected to and drivable by the actuator 14. Accordingly, when the actuator 14 is operated, the actuator axle 18 performs corresponding rotating movements.

[0068] The flag actuation system 12 further comprises two flags 13a, 13b, each being mounted pivotally on the actuator axle 18, and each being magnetically connectable to the actuator axle 18, thereby allowing the flags 13a, 13b to move along with the actuator axle 18 when it performs rotating movements as described above. This will be described in further detail below.

[0069] An adapter part 19 is arranged between the flags 13a, 13b, and mounted fixedly on the actuator axle 18. Thus, when the actuator axle 18 performs rotating movements, the adapter part 19 always rotates along.

[0070] The adapter part 19 has two magnets 20 mounted thereon, and each of the flags 13a, 13b has an actuator magnet 21a, 21b mounted thereon. When the adapter part 19 is in an angular position where one of the magnets 20 is aligned with the actuator magnet 21a, 21b of one of the flags 13a, 13b, then a magnetic connection is established which connects that flag 13a, 13b to the adapter part 19, and thereby to the actuator axle 18. The flag 13a, 13b then moves along when the actuator axle 18 performs rotating movements.

[0071] It can be seen that the position of the actuator magnet 21a on flag 13a differs from the position of the actuator magnet 21b on flag 13b. Thereby the actuator magnets 21a, 21b will not be aligned with the same magnet 20 of the adapter part 19 simultaneously, i.e. at the same angular position of the adapter part 19. Thereby angular positions of the adapter part 19 exist, where zero, one or two of the flags 13a, 13b are magnetically connected to the adapter part 19. More specifically, the adapter part 19 can be positioned in angular positions where the following configurations are obtained: [0072] 1. None of the magnets 20 are aligned with an actuator magnet 21a, 21b. [0073] 2. One of the magnets 20 is aligned with actuator magnet 21a, but none of the magnets 20 are aligned with actuator magnet 21b. [0074] 3. One of the magnets 20 is aligned with actuator magnet 21b, but none of the magnets 20 are aligned with actuator magnet 21a. [0075] 4. One of the magnets 20 is aligned with actuator magnet 21a and the other of the magnets 20 is aligned with actuator magnet 21b.

[0076] In configuration (1) none of the flags 13a, 13b are connected to the actuator axle 18, and the actuator axle 18 can rotate without moving any of the flags 13a, 13b.

[0077] In configuration (2) flag 13a is connected to the actuator axle 18, but flag 13b is not connected to the actuator axle 18. Thus, flag 13a will rotate along when the actuator axle 18 performs rotating movements, and flag 13b will remain in its current position. Accordingly, in configuration (2), flag 13a can be moved as desired, independently of flag 13b.

[0078] Similarly, in configuration (3) flag 13b is connected to the actuator axle 18, but flag 13a is not connected to the actuator axle 18. Thus, flag 13b will rotate along when the actuator axle 18 performs rotating movements, and flag 13a will remain in its current position. Accordingly, in configuration (3), flag 13b can be moved as desired, independently of flag 13a.

[0079] In configuration (4) flag 13a as well as flag 13b is connected to the actuator axle 18. Accordingly, both flags 13a, 13b are rotated along with the actuator axle 18 simultaneously.

[0080] The flag actuation system 12 further comprises a first mechanical end stop 22 and a second mechanical end stop 23, the mechanical end stops 22, 23 being made from a magnetic or magnetisable material. The mechanical end stops 22, 23 prevent the flags 13a, 13b from moving further when they have been moved into abutment with one of the mechanical end stops 22, 23. Accordingly, the rotating movements of the flags 13a, 13b are limited to movements between a position where they abut the first mechanical end stop 22 and a position where they abut the second mechanical end stop 23. In the position where the flags 13a, 13b abut the first mechanical end stop 22, the flags 13a, 13b are arranged in complete overlap with the aperture 17, and thereby in the optical path through the flag actuation system 12. In the position where the flags 13a, 13b abut the second mechanical end stop 23, the flags 13a, 13b are arranged with no overlap with the aperture 17, and thereby completely out of the optical path through the flag actuation system 12. Thus, each of the flags 13a, 13b is movable between a first position in which it is arranged in the optical path and a second position in which it is arranged out of the optical path.

[0081] Each flag 13a, 13b is provided with a first retaining magnet 24a, 24b and a second retaining magnet 25a, 25b. When a flag 13a, 13b is arranged in abutment with the first mechanical end stop 22, a magnetic retaining connection is established between the first mechanical end stop 22 and the first retaining magnet 24a, 24b of that flag 13a, 13b, thereby retaining the flag 13a, 13b in the first position, at least if the magnetic connection between the flag 13a, 13b and the adapter part 19 is disrupted.

[0082] Similarly, when a flag 13a, 13b is arranged in abutment with the second mechanical end stop 23, a magnetic retaining connection is established between the second mechanical end stop 23 and the second retaining magnet 25a, 25b of that flag 13a, 13b, thereby retaining the flag 13a, 13b in the second position.

[0083] FIGS. 4-12 are perspective views of the flag actuation system 12 of FIG. 3 with the flags 13a, 13b in various positions.

[0084] In FIG. 4 both of the flags 13a, 13b are arranged in the second position, i.e. in abutment with the second mechanical end stop 23 and completely out of the optical path. Furthermore, the adapter part 19 is in an angular position where the actuator magnet 21a of flag 13a as well as the actuator magnet 21b of flag 13b is arranged in alignment with one of the magnets (not visible in FIG. 4) of the adapter part 19. Accordingly, rotating movements of the actuator axle 18 will cause both of the flags 13a, 13b to rotate along.

[0085] FIGS. 5 and 6 show the flags 13a, 13b in an alternative position. FIG. 5 is a slightly exploded view, in order to reveal more details, and FIG. 6 shows the flag actuation system 12 fully assembled.

[0086] In FIGS. 5 and 6, both of the flags 13a, 13b are arranged in the first position, i.e. in abutment with the first mechanical end stop 22 and completely in the optical path. Furthermore, similarly to the situation illustrated in FIG. 4, the actuator magnets 21a, 21b of each of the flags 13a, 13b is aligned with one of the magnets 20 of the adapter part 19, and thereby both of the flags 13a, 13b will move along when the actuator axle 18 rotates. Thus, the flags 13a, 13b have simply been moved simultaneously from the position shown in FIG. 4 to the position shown in FIGS. 5 and 6 by rotating the actuator axle 18.

[0087] FIGS. 7 and 8 show the flags 13a, 13b in yet an alternative position, where FIG. 7 is a slightly exploded view and FIG. 8 shows the flag actuation system 12 fully assembled.

[0088] In FIGS. 7 and 8, one of the flags 13a is arranged in the first position, as described above with reference to FIGS. 5 and 6, and the other flag 13b is arranged in the second position, as described above with reference to FIG. 4. The adapter part 19 is in an angular position where one of the magnets 20 is aligned with the actuator magnet 21a of flag 13a. However, actuator magnet 21b of flag 13b is not aligned with a magnet 20 of the adapter part 19. Thus, when the actuator axle 18 rotates, flag 13a will move along, but flag 13b will remain in the first position.

[0089] FIGS. 9 and 10 show the flags 13a, 13b in yet an alternative position, where FIG. 9 is a slightly exploded view and FIG. 10 shows the flag actuation system 12 fully assembled.

[0090] In FIGS. 9 and 10, flag 13b is arranged in the first position and flag 13a in arranged in the second position, i.e. the positions of the flags 13a, 13b are reversed as compared to the situation illustrated in FIGS. 7 and 8. The adapter part 19 is in an angular position where one of the magnets 20 is aligned with the actuator magnet 21b of flag 13b. However, actuator magnet 21a of flag 13a is not aligned with a magnet 20 of the adapter part 19. Thus, in the situation illustrated in FIGS. 9 and 10, it is flag 13b which will move along when the actuator axle 18 rotates, while flag 13a will remain in the second position.

[0091] FIGS. 11 and 12 show the flags 13a, 13b in yet an alternative position, where FIG. 11 is a slightly exploded view and FIG. 12 shows the flag actuation system 12 fully assembled.

[0092] In FIGS. 11 and 12, flag 13b is arranged in the first position, and flag 13a is in an intermediate position between the first position and the second position. The adapter part 19 is in an angular position where one of the magnets 20 is aligned with actuator magnet 21a of flag 13a, and where none of the magnets 20 are aligned with actuator magnet 21b of flag 13b. Accordingly, flag 13a is moved along when the actuator axle 18 rotates, and flag 13b remains in the first position. Thus, flag 13a is in the process of being moved into or out of the optical path.

[0093] FIG. 13 is a perspective view of a flag actuation system 12 according to a second embodiment. The flag actuation system 12 of FIG. 13 is very similar to the flag actuation system 12 illustrated in FIGS. 3-12, and it will therefore not be described in detail here. However, the flag actuation system 12 of FIG. 13 comprises three flags 13a, 13b, 13c and two adapter parts 19a, 19b. Adapter part 19a is arranged between flag 13a and flag 13b, and adapter part 19b is arranged between flag 13b and flag 13c. Flag 13a and flag 13b are arranged in the first position, and flag 13c is arranged in the second position.

[0094] Each of the adapter parts 19a, 19b has two magnets (not visible) mounted thereon, and each of the flags 13a, 13b, 13c has an actuator magnet 21a, 21b, 21c mounted thereon. One of the magnets of adapter part 19b is aligned with the actuator magnet 21c of flag 13c. One of the magnets of adapter part 19a is aligned with the actuator magnet 21b of flag 13b, and the other of the magnets of adapter part 19a is aligned with the actuator magnet 21a of flag 13a. Accordingly, all of the flags 13a, 13b, 13c are magnetically connected to the actuator axle 18.

[0095] If the actuator axle 18 is rotated in a clockwise direction, flag 13c will be retained by the second mechanical end stop 23, and adapter part 19b will rotate relative to flag 13c, thereby disrupting the magnetic connection between flag 13c and adapter part 19b. Simultaneously, flag 13a and 13b will be moved along with the actuator axle 18 towards the second position and out of the optical path.

[0096] If the actuator axle 18 is rotated in a counter-clockwise direction, flag 13a and flag 13b will be retained by the first mechanical end stop, and the magnetic connections between flags 13a, 13b and adapter part 19a will be disrupted, while flag 13c will move along with the actuator axle 18 towards the first position and into the optical path.

[0097] FIG. 14 illustrates a method according to an embodiment for controlling a flag actuation system comprising two flags. The flag actuation system being controlled may, e.g., be the flag actuation system illustrated in FIGS. 3-12.

[0098] The process is started at step 26. At step 27 the actuator axle, and possibly an adapter part, is rotated 360°, in order to ensure that both flags are moved to a specified position and that none of the flags are magnetically connected to the actuator axle.

[0099] At step 28 a combination of flags to be arranged in the optical path is selected among four possible flag combinations 29a, 29b, 29c, 29d. Flag combination 29a specifies that both flags should be arranged in the optical path. Flag combination 29b specifies that only flag number 1 should be arranged in the optical path. Flag combination 29c specifies that only flag number 2 should be arranged in the optical path. Finally, flag combination 29d specifies that none of the flags should be arranged in the optical path.

[0100] Finally, a movement pattern 30a, 30b, 30c, 30d for the actuator axle is selected which results in the specified flag combination 29a, 29b, 29c, 29d being arranged in the optical path. The movement pattern 30a, 30b, 30c, 30d is selected from a set of predefined movement patterns 30a, 30b, 30c, 30d, where each is uniquely associated with a flag combination 29a, 29b, 29c, 29d.

[0101] If both flags should be arranged in the optical path, corresponding to flag combination 29a, then the actuator axle must be rotated 90° in a counter-clockwise direction, corresponding to movement pattern 30a.

[0102] If only flag number 1 should be arranged in the optical path, corresponding to flag combination 29b, then the actuator axle must initially be rotated 270° in a clockwise direction and subsequently rotated 45° in a counter-clockwise direction, corresponding to movement pattern 30b.

[0103] If only flag number 2 should be arranged in the optical path, corresponding to flag combination 29c, then the actuator axle must initially be rotated 90° in a clockwise direction and subsequently rotated 45° in a counter-clockwise direction, corresponding to movement pattern 30c.

[0104] If none of flags should be arranged in the optical path, corresponding to flag combination 29d, then the actuator axle must be rotated 360° in a clockwise direction, corresponding to movement pattern 30d.