Range sensing and safety system for lighting device

Abstract

An automatic lighting apparatus and method are provided. The automatic lighting device comprises a range sensing module and a control system. The range sensing module calculates a distance to a closest object in a direction directed by the automatic lighting device. When the distance is less than a threshold distance, the control system reduces a beam power density of the beam emitted from the automatic lighting device. The method includes determining whether an outgoing beam power determinant of the automatic lighting device changes; if so, calculating a threshold distance from the current value of the one or more beam power determinants; determining whether the distance to the closest object is greater than a threshold distance; if not, the beam power density of the beam emitted by the automatic lighting device is reduced.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of U.S. Provisional Patent Application No. 63 / 579,736, filed on August 30, 2023, entitled "RANGE SENSING AND SAFETY SYSTEM FOR ALUMINAIRE," the entire contents of which are hereby incorporated by reference. Technical Field

[0003] The present disclosure relates generally to lighting devices and, more particularly, to range sensing and safety systems for automated lighting devices. Background Art

[0004] Some lighting fixtures in the entertainment and architectural lighting markets include automatic and remote control functions. Such lighting fixtures can be used in theaters, television studios, concerts, theme parks, nightclubs and other venues. The lighting fixture can provide control of the pan and tilt functions of the lighting fixture, allowing the operator to control the direction in which the lighting fixture is pointed, thereby controlling the position of the light beam on the stage or studio. This position control can be obtained via control of the lighting fixture on two orthogonal rotation axes, which can be referred to as pan and tilt. Some lighting fixtures also provide control of other parameters (such as intensity, color, focus, beam size, beam shape and / or beam pattern).

[0005] The optical system of such automatic lighting devices can be designed to enable the user to control the beam size, from a very narrow output beam to a wider wash beam. Such control can allow such lighting devices to be used to project light to a target at a long distance or for nearly parallel light effects, as well as for wider, more traditional wash effects. Optical systems that have the ability to produce narrow beams can be referred to as "beam" optics, while optical systems that have the ability to produce wide beams can be referred to as "wash" optics. Summary of the invention

[0006] In a first embodiment, an automatic lighting device includes a range sensing module and a control system. The range sensing module is configured to calculate a measured distance to the closest object in the direction in which the automatic lighting device is pointed. The control system is configured to receive the measured distance from the range sensing module and reduce the outgoing beam power density of the outgoing beam emitted from the automatic lighting device when the value of the measured distance is less than a predetermined threshold distance value.

[0007] In a second embodiment, the range sensing module is configured to mechanically couple to the automatic lighting device; electrically couple to the control system of the automatic lighting device; measure the distance to an object in the direction in which the automatic lighting device is pointing; and send the measured distance to the control system of the automatic lighting device.

[0008] In a third embodiment, a method for controlling the intensity of a light beam emitted by an automatic lighting device includes determining whether an outgoing beam power determinant of the automatic lighting device has changed; if the outgoing beam power determinant has changed, calculating a threshold distance from current values ​​of one or more beam power determinants; determining whether a measured distance to the closest object in a direction in which the automatic lighting device is pointed is greater than the threshold distance; and if the measured distance is not greater than the threshold distance, reducing the outgoing beam power density of the outgoing beam emitted by the automatic lighting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For a more complete understanding of the present disclosure, reference is now made to the following brief description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like features.

[0010] Figure 1 An isometric view of a lighting device according to the present disclosure is shown;

[0011] Figure 2A Demonstrated according to the present disclosure Figure 1 An isometric view of a head of a lighting device with a range sensing module attached to the head;

[0012] Figure 2B Shown Figure 2A An exploded isometric view of the head of the vehicle with the range sensing module removed from the head;

[0013] Figure 3 shows an exploded isometric view of a range sensing module according to the present disclosure;

[0014] Figure 4 showing a graphical representation of a range sensing module in use according to the present disclosure; and

[0015] Figure 5 A flow chart of a process for controlling the intensity of a light beam emitted from a lighting device according to the present disclosure is presented. DETAILED DESCRIPTION

[0016] Preferred embodiments are illustrated in the drawings, wherein like reference numerals are used to designate like and corresponding parts throughout the several views.

[0017] Some lighting devices (both automatic and non-automatic) include a light source that includes a discharge lamp or an array of light emitting diodes (LEDs) with converging optics. A lighting device according to the present disclosure includes one or more laser-based light sources, in which the laser LED is used as a pump for luminescent phosphors. The light source of such a system is designed to be smaller and have a lower light collection rate. In some embodiments, a light source according to the present disclosure includes a laser-based light engine that includes one or more lasers of one or more colors and one or more optical devices that convert a coherent light beam emitted by the laser into an incoherent light beam. Such a laser may include a solid-state LED laser. The optical device may include a fluorescent panel or filter. In some such embodiments, the light engine includes a solid-state LED laser that emits coherent blue light, which excites the phosphor to emit incoherent white light.

[0018] The lighting device including the light source according to the present disclosure may include various optical systems: a fixed "beam" optical system that produces a narrow beam, a fixed "dye" optical system that produces a wide beam, or a zoom optical system that can change the beam diameter from a narrow beam to a wide beam. Such a zoom optical system can also produce high-quality images by inserting a lens baffle or pattern of the optical train.

[0019] Lighting devices that emit extremely narrow beams of light (e.g., from laser-based light sources) may emit beams with high exit beam power density. Such beams may cause damage to the eyes or bodies of persons in the beam, or damage to scenery, structures, or fabrics if the exit beam power density exceeds certain predetermined threshold power density values. Therefore, lighting devices that emit such beams may be subject to various regulatory controls in various jurisdictions.

[0020] Although the light output from such laser-based light sources is not coherent laser light, as described above, it is still possible to have a higher exit beam power density. Illumination devices according to the present disclosure include methods and systems for meeting regulatory requirements and mitigating potential physical issues with high power density exit beams.

[0021] Figure 1An isometric view of a lighting device 100 according to the present disclosure is shown. The lighting device 100 is an automatic lighting device including a head 128 coupled to a tilt mechanism for rotation about a tilt axis 124 within a yoke 120. The yoke 120 is coupled to a translation mechanism for rotation about a translation axis 122 relative to a fixed housing 126. The translation axis 122 and the tilt axis 124 are orthogonal to each other. Thus, an operator of the lighting device 100 is able to direct the light output from the automatic lighting device in a desired direction by rotation of the head 128 about the translation axis 122 and the tilt axis 124. The yoke 120 and the head 128 may be mechanically coupled to a manually operated control for rotation about the translation axis 122 and the tilt axis 124, respectively, or may be coupled to a motor, a linear actuator, or other electromechanical control mechanism to achieve motion and control the direction of the yoke 120 and the head 128.

[0022] Such an electromechanical mechanism can be electrically coupled to a control system (or controller) 102 of the lighting device 100, which is configured to control the movement of the electromechanical mechanism, thereby controlling the orientation of the yoke 120 and the head 128. In various embodiments, the control system 102 includes a microcontroller or other programmable processing system. In some embodiments, the control system 102 can be coupled to a user interface 104 included in the lighting device 100 for local control and is configured to receive signals therefrom related to the desired orientation of the yoke 120 and the head 128.

[0023] In other embodiments, the control system 102 may be coupled to a remote control console via a data link (wired or wireless) for remote control and receive a signal therefrom indicating the desired orientation of the head 128. The data link may use a DMX512 (digital multiplexing) protocol or other suitable communication protocols, such as Art-Net, ACN (Architecture of Control Networks), and streaming ACN. In such embodiments, the control system 102 is configured to move the translation mechanism and / or the tilt mechanism in response to a signal received via the data link. In some such embodiments, the control system 102 moves the translation mechanism in response to a control signal received on a first control channel of the data link, and moves the tilt mechanism in response to a control signal received on a second control channel of the data link.

[0024] The lighting device 100 further includes a range sensing module 110 including a first range sensing system 114 electrically coupled to the control system 102. In some embodiments, the range sensing module 110 may further include a second range sensing system 112 also electrically coupled to the control system 102.

[0025] Figure 2A An isometric view of the head 128 with the range sensing module 110 attached is shown. Figure 2B An exploded isometric view of the head 128 is shown with the range sensing module 110 removed. Although the range sensing module 110 is shown mounted on the head 128 of the automated lighting device 100, range sensing modules (and associated lighting device control system safety procedures) according to the present disclosure may be used with other types of lighting devices (e.g., automated and non-automated lighting devices, as well as mobile and static lighting devices) in other embodiments.

[0026] Figure 3 An exploded isometric view of the range sensing module 110 is shown. The first range sensing system 114 includes a first range sensor 302 mounted in a hole 303 of the range sensing module 110. The first range sensor 302 is mounted behind a window 304 to prevent the ingress of airborne substances and moisture. The first range sensor 302 is mounted to the range sensing module 110 by a bracket 306 and is covered by a cover 308. The second range sensing system 112 includes Figure 3 Range sensing systems 112 and 114 are configured to be electrically coupled to control system 102 .

[0027] In some embodiments, the range sensing systems 112 and 114 may include a light detection and ranging (LiDAR) range sensor. LiDAR is a method of determining the distance to an object using the measured time of flight of a pulse of light traveling outward from a sensor, reflecting from an object, and returning to the sensor. LiDAR range sensing systems are similar to radar systems, but use light instead of radio waves. LiDAR range sensors such as those used in range sensing systems 112 and 114 may have a measurement range of over 150 m (meters) with a measurement accuracy of a few millimeters. In some embodiments, the range sensing module 110 may include only one of the range sensing systems 112 and 114.

[0028] Figure 4 A graphical representation of the range sensing module 110 in use is shown. The first range sensing system 114 continuously emits light pulses 402 and receives light pulses reflected from the closest object in the direction the lighting device 100 is currently pointing. Figure 4 , the closest object is object 404. The first range sensing system 114 calculates a measured distance 406 to the object 404 based on the time between the emission of the pulse and the receipt of the reflected light pulse. The control system 102 is configured to identify the object 404 as the closest object that the light beam emitted by the lighting device 100 may illuminate. Figure 4 In the illustration, object 404 is shown as a person, but in various applications, object 404 may be a wall, a set element, a seating area, or other part of the performance space structure or content.

[0029] The first range sensing system 114 continually and repeatedly reports the measured distance 406 to the control system 102. As the lighting device moves (or as an object moves in front of the lighting device 100), the object 404 may move out of or be moved out of the light beam, while new objects move into or are moved into the light beam, causing the first range sensing system 114 to report a new measured distance 406 from the lighting device 100 to the new, closest object to the control system 102.

[0030] In some embodiments, the control system 102 is configured to sweep the pan and tilt mechanisms of the lighting device 100 through all (or some) possible pan / tilt positions to determine "no-go" pan / tilt positions in which the lighting device 100 is pointed at an object having a measured distance 406 less than a threshold distance value. Such positions (or ranges of such positions) may be referred to as intensity control ranges. In other embodiments, as discussed in more detail below, an operator of the lighting device 100 identifies the intensity control range. In various embodiments, such intensity control ranges are stored in a memory of the control system 102, in a lookup table or other data structure. A lighting device is considered to be within the intensity control range when its translation position is within a translation position or a translation position range of the intensity control range, and its tilt position is within a tilt position or a tilt position range of the intensity control range.

[0031] The control system 102 is configured to execute a safety procedure to control the light beam emitted by the lighting device 100 based on one or more of the following: (i) the current position of the pan and tilt system; (ii) the current outgoing beam power density of the lighting device 100; and (iii) the measured distance 406 received from the first range sensing system 114. The current outgoing beam power density of the light beam can be determined based on the current output power of the light source, the losses in the optical system, and the beam angle of the outgoing beam (e.g., calculated based on the configuration of the zoom lens). Devices of the optical system (optical devices) that the light beam passes through before being emitted from the lighting device 100 and whose configuration may affect the current outgoing beam power density include color filters, lens baffles, neutral density filters, and intensity apertures.

[0032] In some embodiments, if the lighting device 100 is currently emitting light at a beam angle below a predetermined threshold angle (e.g., the power density produced in the beam is high enough to be subject to regulatory restrictions), the control system 102 is configured to reduce or disable light output from the lighting device 100 if the measured distance 406 is less than the threshold distance value. The safety program of the control system 102 will allow full light output from the lighting device 100 only when the measured distance 406 is greater than the threshold distance value.

[0033] In some embodiments, this range sensing and safety routine operates at all times when the lighting device 100 is powered on. Thus, even during setup, when scenery, seating areas, or other portions of the structure are being prepared for a show, and / or when workers are on stage, the control system 102 is configured to reduce or disable light output when an object is detected at a measured distance 406 less than a threshold distance value. The threshold distance value may be preset (or predetermined) based on one or both of local regulations and outgoing beam power determining factors (e.g., light source power, zoom configuration, and / or optical system configuration). In some embodiments, the threshold distance value is repeatedly calculated based on the current outgoing beam power density of the light beam emitted by the lighting device 100.

[0034] Some regulations stipulate the maximum permissible value of the power density of the emitted beam, which is expressed in watts per square meter (W / m 2 ), which is the ratio of the emitted beam power (in watts) to the illuminated area. This ratio value decreases when the power of the light source is reduced, the beam is dimmed by other means, or the beam size is increased (resulting in a larger area illuminated by the beam). The beam size may increase due to an increase in one or both of the beam angle or the measured distance 406. For example, if the threshold distance value is set to 10 meters when the beam angle is 1° (degrees), the threshold distance value may increase to 20 meters when the beam angle is 4°, and further increase to 30 meters when the beam angle is 8°.

[0035] In some embodiments, the control system 102 is configured to use a lookup table that provides a predetermined threshold distance value based on the current value of one or more of the outgoing beam power determinants. Such embodiments may include a lookup table that groups the threshold distance values ​​by range of values ​​of one or more of the outgoing beam power determinants. In other embodiments, the control system 102 is configured to pre-calculate the predetermined threshold distance value when any outgoing beam power determinant changes.

[0036] In some embodiments, the range sensing module 110 may include a second range sensing system 112 to provide redundancy. In some such embodiments, the control system 102 is configured to compare the measured distances 406 reported by the range sensing systems 112 and 114 and use the closer measured distance 406. In other such embodiments, the control system 102 is configured to use the measured distance 406 from the second range sensing system 112 if it is determined that the first range sensing system 114 has failed. In still other such embodiments, if both range sensing systems 112 and 114 fail (or provide measured distances 406 that differ by more than a threshold difference), the control system 102 completely shuts down the operation of the lighting device 100 in accordance with its safety procedures.

[0037] In some embodiments, the zoom and / or focus lens mechanism of the lighting device 100 includes one or more lens position sensors configured to sense the actual lens position of the lenses within the lighting device 100, separate from the sensors in the zoom lens positioning mechanism and the focus lens positioning mechanism. In such embodiments, the control system 102 is configured to determine from the values ​​of the one or more lens position sensors whether the lighting device 100 actually emits a beam having the beam angle commanded by the control system 102. This may occur, for example, if the lens positioning mechanism associated with the lens position sensor loses calibration or is not operating properly. If the actual beam angle of the emitted beam is different from the commanded beam angle, the control system 102 is configured to determine whether to reduce the emitted beam power density of the beam emitted by the lighting device 100.

[0038] In some embodiments, the pan and tilt positioning mechanism (lighting device head direction mechanism) of the lighting device 100 similarly includes an orientation sensor configured to sense the actual orientation of the lighting device head 128. Such an orientation sensor is separate from the sensor in the associated lighting device head motion mechanism. In still other embodiments, the lighting device head 128 may include an accelerometer configured to sense the orientation of the lighting device head 128 relative to the ground and / or the performance space. In such embodiments, the control system 102 is configured to determine whether the lighting device head 128 is actually in the orientation commanded by the control system 102 based on the value of the sensed actual current orientation of the lighting device head 128. If the control system 102 determines that the sensed actual current orientation of the lighting device head 128 is different from the orientation commanded by the control system 102, the control system 102 is configured to reduce the outgoing beam power density of the light beam emitted from the lighting device 100 (e.g., if the pan and tilt positioning mechanism fails or the lighting device head 128 is physically moved out of position).

[0039] The control system 102 may be configured to use the measured distances 406 from the range sensing module 110 and any or all of the pan / tilt directions, absolute position data, and / or accelerometer data commanded by the control system 102 to build a three-dimensional (3D) model of the performance space from the viewpoint of the lighting device 100. Such a 3D model may be built by the control system 102 moving the lighting device head 128 through all or a subset of its directions and storing the measured distances 406 in some or all of these directions. In this manner, an expected distance lookup table or other data structure may be created that enables the control system 102 to determine the expected distance of an object in a commanded pan / tilt direction based on that direction. Such expected distance values ​​may be used to check the correctness of the current measured distances 406 from the range sensing module 110, or to check whether the 3D model is still an accurate model of the environment of the lighting device 100.

[0040] In some embodiments, the control system 102 is configured to display such a 3D model to an operator of the lighting device 100 for use by the operator in identifying intensity control areas in the performance space—e.g., adjacent portions of an auditorium—where, for safety reasons, narrow-angle beams may never be projected. In some such embodiments, the control system 102 is configured to send the 3D model to an external device, and the operator may interact with a display of the 3D model to identify intensity control areas in the performance space. In such embodiments, the control system 102 is further configured to receive information identifying “intensity control” areas in the performance space from the external device, and use such received information to define a pan / tilt position or range for intensity control, as described above. In some such embodiments, when an operator of the lighting device 100 issues a command for an “intensity control” pan / tilt position, a safety procedure implemented by the control system 102 may reduce the beam intensity regardless of the currently measured distance 406 to the range sensing module 110.

[0041] The safety program implemented by the control system 102 of the lighting device 100 provides a range sensing and safety system using the range sensing module 110 in accordance with the present disclosure, and in some embodiments, also provides actual current position feedback of the zoom lens mechanism and the focus lens mechanism, actual position feedback of the pan / tilt mechanism positioning and / or an accelerometer for monitoring the actual direction of the lighting device head 128.

[0042] Figure 5 A flow chart of a process for controlling the intensity of a beam emitted from a lighting device according to the present disclosure is shown. The process first checks for changes in the values ​​of the outgoing beam power determinants: zoom configuration, light source power, and optical system configuration. Such changes may cause the control system 102 to reduce the outgoing beam power density or allow it to return to full intensity. In steps 502, 504, and 506, the control system 102 checks for changes in the zoom lens system configuration, the power applied to the light source, and the configuration of the optical devices of the optical system, respectively. If a change in any of these outgoing beam power determinants is detected, the method 500 continues to step 508, where the control system 102 calculates and stores the minimum allowed threshold distance value for the current outgoing beam power density of the beam emitted by the lighting device 100. The threshold distance value is the minimum distance from the lighting device at which the outgoing beam power density of the outgoing beam is below a predetermined threshold power density value. The control system 102 performs the calculation using all configurations of the zoom lens system, the power applied to the light source, and the current values ​​of the configuration of the optical devices of the optical system. As described below, if the distance to an object in the light beam is less than the calculated threshold distance value, the control system 102 may reduce the outgoing beam power density of the light beam to a safer predetermined outgoing beam power density.

[0043] In some embodiments, the control system 102 controls the variable power applied to the light source by current control or voltage pulse width modulation (PWM). In these embodiments, in step 504, the control system 102 checks whether the value of the variable power applied to the light source has changed. In other embodiments, the control system 102 only controls whether power is supplied to the light source - on / off control. In such embodiments, in step 504, the control system 102 checks whether the light source has been powered on or powered off since the previous iteration of the method 500.

[0044] As mentioned above, regulations may specify a maximum permissible value for the outgoing beam power density, expressed in W / m 2 The outgoing beam power density decreases when the electrical power of the light source is reduced, when the beam is dimmed by the configuration of the optical system, or when the configuration of the zoom lens system increases the size of the outgoing beam, resulting in an increase in the area illuminated by the beam. The beam size also increases with increasing distance from the lighting device 100. Therefore, a minimum allowable threshold distance can be calculated, above which the outgoing beam is safe and below which the outgoing beam is not considered safe.

[0045] Back to Figure 5 , in step 510, the control system 102 determines whether the measured distance 406 is greater than a stored threshold distance value. Step 510 is performed either after the threshold distance value is calculated and stored in step 508, or after it is determined in steps 502, 504, and 506 that no outgoing beam power determining factors have changed. If the control system 102 determines in step 510 that the measured distance 406 is not greater than the stored threshold distance value, then in step 512 the control system 102 reduces the outgoing beam power density to obtain safer operation of the lighting device 100. In some embodiments, the outgoing beam is physically blocked by a blind or other device. In other embodiments, the power applied to the light source is reduced and / or the size of the outgoing beam is increased (wider beam angle). The actions performed in step 512 may result in no outgoing beam or an outgoing beam that is safe at any distance from the lighting device 100. From step 512, the control system 102 enters step 502 to begin another iteration of the method 500.

[0046] If the control system 102 determines in step 510 that the measured distance 406 is greater than the stored threshold distance value, then in step 514 the control system determines whether the pan and tilt positions are both within their respective "intensity control" ranges, as described above. If the pan and tilt positions are both within their respective "intensity control" ranges, the method 500 proceeds to step 512, in which the control system 102 reduces the outgoing beam power density to achieve safer operation of the lighting device 100. If one or both of the pan and tilt positions are outside their respective "intensity control" ranges, then in step 516 the control system 102 cancels any reduction in outgoing beam power density previously applied in step 512, allowing the lighting device to return to full outgoing beam power density. Therefore, before the control system 102 allows the lighting device to return to full outgoing beam power density, two conditions need to be determined: (i) the measured distance 406 is greater than the stored threshold distance value and (ii) the pan and tilt positions are both not within their respective "intensity control" ranges.

[0047] In step 516, any or all of the following operations may be performed to allow the lighting device to return to its full outgoing beam power density: removing the physical obstruction of the outgoing beam, restoring the power applied to the light source to the higher commanded level, and moving the optical system from the safe configuration to the commanded beam angle. From step 516, the control system 102 proceeds to step 502 to begin another iteration of the method 500.

[0048] Although only some embodiments of the present disclosure have been described herein, those skilled in the art who benefit from the present disclosure will appreciate that other embodiments can be designed without departing from the scope disclosed herein. Although the present disclosure has been described in detail, it should be understood that various changes, substitutions and modifications can be made thereto without departing from the spirit and scope of the present disclosure.

Claims

1. An automatic lighting device, comprising: a range sensing module configured to calculate a measured distance to a closest object in a direction in which the automatic lighting device is pointed; as well as A control system, the control system being configured to: receiving the measured distance from the range sensing module; as well as When the measured distance value is less than a predetermined threshold distance value, an outgoing beam power density of an outgoing beam emitted from the automatic lighting device is reduced.

2. The automatic lighting device of claim 1, wherein the range sensing module comprises a light detection and ranging (LiDAR) range sensor.

3. The automatic lighting device according to claim 1, wherein the emitted light beam is an incoherent light beam emitted by a luminescent phosphor pumped by laser LED light.

4. The automatic lighting device of claim 1 , wherein the control system is configured to calculate the predetermined threshold distance value as a minimum distance from the lighting device at which the outgoing beam power density of the outgoing beam is lower than a predetermined threshold power density value.

5. The automatic lighting device according to claim 1, wherein the control system is configured to reduce the outgoing beam power density of the outgoing beam by changing the configuration of the outgoing beam power determining factor to a selected configuration so that the lighting device emits a light beam with a predetermined outgoing beam power density, in, The outgoing light beam power determining factors include one or more of the following: (i) a zoom lens system configured to control the beam angle of the outgoing light beam, (ii) power applied to a light source configured to generate the outgoing light beam, and (iii) a configuration of an optical system through which the outgoing light beam passes before being emitted from the automatic lighting device. 6 . The automatic lighting device according to claim 1 , wherein the control system is configured to reduce the outgoing beam power density of the outgoing beam by physically blocking the beam.

7. The automatic lighting device according to claim 1, further comprising: a lens position sensor in the lens mechanism of the automatic lighting device, the lens position sensor being configured to sense an actual lens position of the lens mechanism, wherein the lens position sensor is separated from a sensor in an associated lens positioning mechanism, The control system is configured as follows: determining whether the automatic lighting device emits an outgoing light beam having a beam angle commanded by the control system based on the value of the lens position sensor; and When the outgoing beam has a beam angle that is different from the beam angle commanded by the control system, the outgoing beam power density of the outgoing beam is reduced.

8. The automatic lighting device according to claim 1, further comprising: an orientation sensor in a lighting device head orientation mechanism of the automatic lighting device, the orientation sensor being configured to sense the actual current orientation of the head of the automatic lighting device, wherein the orientation sensor is separate from a sensor in an associated lighting device head movement mechanism, The control system is configured as follows: determining, based on the value of the direction sensor, whether the head of the automatic lighting device has the direction commanded by the control system; and When the direction of the head of the automatic lighting device is different from the direction commanded by the control system, the outgoing beam power density of the outgoing beam is reduced.

9. The automatic lighting device of claim 1 , wherein the control system is configured to calculate the predetermined threshold distance value from one or more of: (i) a configuration of a zoom lens system configured to control a beam angle of the outgoing light beam, (ii) power applied to a light source configured to generate the outgoing light beam, and (iii) a configuration of an optical system through which the outgoing light beam passes before being emitted from the automatic lighting device.

10. An automatic lighting device according to claim 9, wherein the control system is configured to calculate the predetermined threshold distance value using a lookup table, the lookup table including threshold distance values ​​determined by one or more of the zoom lens system configuration, the power applied to the light source, and the optical system configuration.

11. A method of controlling the intensity of a light beam emitted by an automatic lighting device, the method comprising: determining whether a factor determining the power of an outgoing light beam of the automatic lighting device has changed; calculating a threshold distance from current values ​​of one or more beam power determinants if the outgoing beam power determinants have changed; determining whether a measured distance to the closest object in the direction in which the automatic lighting device is pointed is greater than the threshold distance; and If the measured distance is not greater than the threshold distance, the outgoing beam power density of the outgoing beam emitted from the automatic lighting device is reduced.

12. The method according to claim 11, further comprising: If the measured distance is greater than the threshold distance, determining whether the translation position and the tilt position of the automatic lighting device are within an intensity control range; If the translation position and the tilt position are both within the intensity control range, reducing the power density of the emitted light beam; as well as If neither the translation position nor the tilt position is within the intensity control range, the outgoing beam is allowed to return to full outgoing beam power density.

13. The method of claim 11, wherein reducing the output beam power density comprises one or more of the following: physically blocking the outgoing light beam; reducing power applied to a light source of the automatic lighting device; and The beam angle of the outgoing light beam is increased.

14. The method of claim 12, wherein allowing the exit beam to recover to the full exit beam power density comprises one or more of: removing physical obstructions to the outgoing light beam; applying the commanded power level to a light source of the automated lighting device; and The optical system of the automated lighting device is moved to produce the commanded beam angle.

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