Algorithmic control of LED current and switch-on time for eye safety

Abstract

Method for controlling a lighting system, wherein the method comprises Retrieving, by a processor (120) and from a memory (134) of a lighting module (130), device information indicating properties of the lighting module (130), wherein the device information comprises (i) a plurality of parameters of a lighting element of the lighting module (130) and (ii) a maximum constant for the lighting element, wherein the maximum constant indicates a relationship between at least two parameters of the lighting element; Received from a user a desired parameter value for one of the parameters from the multitude of parameters; Determine, by the processor (120), a test constant from the desired parameter value; Determine, using the processor (120) and from the test constant and the maximum constant, that the desired parameter value is an acceptable parameter value; and Control of a power source by the processor (120) to provide electrical current to the lighting module (130) according to the desired parameter value; where the maximum constant also indicates a radiation risk group classification.

Description

BACKGROUND

[0001] Typical barcode readers and image processing systems, such as handheld barcode scanners, POS scanners, and direct part marking scanners, require adequate illumination of the targets to obtain high-quality, low-blur images and decode the barcodes within those images. The light source is crucial for decoding the barcodes in the captured images, and various factors, such as the time of day, the direction of illumination, the intensity, the color of the light, and the type of light source, affect how effectively a system can decode barcodes. Furthermore, the type of barcode, the reflectivity of a target, and the distance or size of the target are also important factors in decoding barcodes in captured images, with each type of barcode potentially requiring a different type of illumination.

[0002] Maintaining eye-safe lighting and operation is critical for lighting systems. Different lighting system manufacturers may require their systems to operate within a specific risk group according to eye safety standards. Maintaining eye-safe operation across multiple systems can be complex because different light sources (e.g., LEDs, laser diodes, etc.) each present distinct eye safety risks and standards, depending on factors such as light coherence and spectrum. Furthermore, each color of illumination has different risk factors, further complicating systems for maintaining eye safety across various LED colors or multi-colored light sources.For example, a lighting system with blue LEDs generally poses a higher risk of eye damage, whereas a green or red LED in the same lighting system, at the same electrical currents and output illuminance levels, can operate within eye safety standards. Therefore, it can be advantageous for a lighting system to operate within the desired eye safety standards by controlling individual light sources so that the overall system maintains these standards during operation.

[0003] US 10,941,911 B1 describes systems and methods for adaptive power driving in a lighting system. An exemplary method includes one or more processors analyzing data in memory to determine a configuration for one or more LEDs; one or more processors receiving lighting control instructions to operate the one or more LEDs during one or more lighting cycles; one or more processors controlling one or more switches of a lighting unit according to the lighting control instructions; one or more processors determining a current requirement to operate the one or more LEDs according to the lighting control instructions; and one or more processors setting a current control setpoint of an LED driver to the current requirement.

[0004] DE 10 2017 207 957 A1 describes a safety circuit for a modulated switchable light source, with a current breaker arranged in the current path of the light source and designed such that, starting from a switch-off signal applied to an input of the current breaker, the current supply to the light source is interrupted, with a first trip circuit for providing a switch-off signal starting from an exceedance of a maximum current (I max ), and with a second trip circuit to provide a shutdown signal based on an exceedance of a maximum average current.

[0005] US 6,661,820 B1 describes a system and method for controlling the operating parameters of a laser diode. The laser control system automatically optimizes the operating characteristics of the laser diode while maintaining a safe peak power for the pulse duration and pulse repetition frequency (PRF). The controlled output power level is based on the laser diode gain, which is determined during the calibration of each laser diode projector, and on the application of predefined laser safety formulas. The laser control system includes a laser diode driven by a laser drive current. The laser diode has a laser output with a peak power level. A detector is coupled to the laser diode to detect the laser power. A laser driver with a primary control loop can regulate the laser driver current, based on the detected laser power and a reference value, so that the output power corresponds to the reference value.A controller is coupled to the laser driver.

[0006] DE 20 2007 009 934 U1 describes a compact lighting module comprising an electrical energy source, a voltage converter and a radiation source for electromagnetic radiation. DESCRIPTION

[0007] According to the invention, a method for controlling lighting is provided. The method comprises retrieving, by a processor and from a memory of a lighting module, device information indicating properties of the lighting module, wherein the device information comprises (i) a plurality of parameters of a lighting element of the lighting module and (ii) a maximum constant for the lighting element, the maximum constant indicating a relationship between at least two parameters of the lighting element. The method further comprises receiving a desired parameter value for one of the parameters from the plurality of parameters from a user. The processor determines a test constant from the desired parameter value and then, based on the test constant and the maximum constant, determines whether the desired parameter value is an acceptable parameter value.The process further includes the processor controlling a power source to supply electrical current to the lighting module according to the desired parameter value. The maximum constant also indicates a radiation risk group classification.

[0008] In one variant of the present embodiment, the maximum constant specifies a proportional relationship between an electric current of the lighting element and an output illumination provided by the lighting element, and wherein the test constant specifies one of (i) a desired electric current of the lighting element or (ii) an output illumination provided by the lighting element.

[0009] In another variant of the current embodiment, determining that the desired parameter value is an acceptable parameter value includes: comparing the test constant and the maximum constant by the processor; and determining, by the processor, that the desired parameter value is an acceptable parameter value if the test constant is equal to or less than the maximum constant, or that the desired parameter value is not an acceptable parameter value if the test constant is greater than the maximum constant.

[0010] According to the invention, a lighting system is provided comprising a lighting connection adapted to accommodate a lighting module which has (i) one or more lighting elements and (ii) a memory that stores device information displayed by the lighting module. The device information includes (i) a plurality of parameters of a lighting element of the lighting module and (ii) a maximum constant for the lighting element, wherein the maximum constant indicates a relationship between at least two parameters of the lighting element.The system further comprises at least one processor operationally connected to the lighting port, the processor being configured to: retrieve device information from the lighting module's memory; receive a desired parameter value for one of the multiple parameters at a user interface; determine a test constant from the desired parameter value; determine, from the test constant and the maximum constant, that the desired parameter value is an acceptable parameter value; and control a power source to supply electrical current to the lighting module according to the desired parameter value. The maximum constant further specifies a radiation risk group classification.

[0011] In one variant of the present embodiment, the lighting module can be selectively removed from the lighting system.

[0012] In another variant of the present embodiment, the maximum constant specifies a proportional relationship between an electric current of the lighting element and an output illumination provided by the lighting element, and wherein the test constant specifies one of (i) a desired electric current of the lighting element or (ii) an output illumination provided by the lighting element.

[0013] In a further variant of the present embodiment, in order to determine that the desired parameter value is an acceptable parameter value, the processor is further configured to: compare the test constant and the maximum constant; and determine that the desired parameter value is an acceptable parameter value if the test constant is equal to or less than the maximum constant, or that the desired parameter value is not an acceptable parameter value if the test constant is greater than the maximum constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying figures, in which identical reference numerals denote identical or functionally similar elements in the individual views, are incorporated into the disclosure together with the following detailed description and form an integral part of the disclosure and serve to further illustrate embodiments of concepts comprising the claimed invention described herein and to explain various principles and advantages of these embodiments. Fig. Figure 1 shows an example of a lighting system that implements the eye safety lighting techniques disclosed herein. Fig. Figure 2 shows an example of a lighting system with LED arrays as lighting elements. Fig. Figure 3A shows an example user interface for a lighting design application. Fig. Figure 3B shows an example user interface for a lighting design application that displays an eye safety warning message. Fig. Figure 4 is a flowchart of a procedure for implementing eye safety lighting as disclosed herein.

[0015] Experts will recognize that elements in the figures are shown for the sake of simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to improve the understanding of embodiments of the present invention.

[0016] Where appropriate, the apparatus and process components have been represented by conventional symbols in the drawings, which show only those specific details relevant to understanding the embodiments of the present invention, so as not to obscure the disclosure with details that are readily apparent to those skilled in the field who refer to the present description. DETAILED DESCRIPTION

[0017] Scanning systems require appropriate target illumination to decode different types of targets. These illumination systems can be designed to illuminate specific targets with particular characteristics. For example, one illumination system might be used to illuminate and scan targets with a narrow field of view at a great distance from the scanning system, while another illumination system might be used to scan targets at close range with a wider field of view. Therefore, it may be desirable for a system to include a modular illumination system that attaches to a lighting port or bay, allowing for the exchange of an illumination module depending on the type or nature of the targets being scanned.

[0018] Lighting systems employ various light sources, such as LEDs, in different colors and with varying current and power specifications. Furthermore, the different light sources, including the focusing mechanisms of the coupled dispersive optics, must comply with eye safety standards to ensure safe operation of the lighting system. A system and method for determining eye-safe operation for a specific lighting module are described. The methods also include the automatic control of the electrical current and the on / off times of individual light sources to enable eye-safe operation for a variety of lighting modules using one or more light sources.

[0019] Fig. Figure 1 shows an example of a lighting system 100 that implements the eye safety lighting techniques described here. Fig. Figure 1 shows the power supply path for the lighting unit in thicker lines, while the control connections are shown in thinner lines. The lighting system 100 can be used in an industrial environment. For example, the lighting system 100 can be used in an assembly line to detect barcodes affixed to parts and / or to detect defects on parts. As shown, the lighting system 100 comprises three main components: an imaging unit 140 for acquiring image data; a lighting unit 130 to provide illumination to facilitate image data acquisition; and a power driver 110 to supply power to the lighting unit 130.

[0020] Starting from the imaging unit 140, the imaging unit 140 can include a camera or a wide-angle camera and all known imaging components for acquiring image data. For example, the imaging unit 140 can include an array of image sensors 142 configured to detect light reflections passing through a lens system. In some embodiments, the imaging unit 140 includes one or more filters configured to filter the reflected light before and / or after it is detected by the image sensors 142.

[0021] The lighting unit 130 comprises one or more LEDs 132 and a memory 134. In the illustrated embodiment, the lighting unit 130 comprises four sets of LEDs 132, each subdivided into two groups 132a-h. Each set can be assigned a switch to controllably prevent the current flow to the respective LEDs 132 within the set. For example, a switch assigned to set 1 can block the current flow to LED groups 132a and 132b. Similarly, each LED grouping can be assigned a switch to controllably direct the current flowing into the LED set past the LED grouping 132a-h. The switches need not be physical switches, such as relays, but can instead be electrical switches implemented via a transistor.In addition, the switches may contain elements that control an amount of current supplied to each LED grouping 132a-h in order to control an amount of illumination provided by corresponding LEDs of the LED groupings 132a-h.

[0022] The memory 134 of the lighting unit 130 can be configured to store various pieces of information about the LEDs 132 or LED properties. For example, the memory 134 can store a category voltage for the LEDs 132, a category current for the LEDs 132, a category temperature for the LEDs 132, a number of LEDs 132, an LED color for the LEDs 132, an LED binning for the LEDs 132, an LED grouping arrangement (e.g., a logical positioning of the LEDs 132 with respect to set and group numbering), a physical arrangement (e.g., a physical arrangement (e.g.,a physical position of the LEDs 132 on the lighting unit 130), relative positions of the LEDs 132 to each other, an LED part number, a physical position and / or orientation of one or more LEDs on a circuit board, an eye-safe current for each of the LEDs 132, an eye-safe power for each of the LEDs 132, an eye-safe illuminance power for each of the LEDs 132, a model number for the lighting unit 130 and / or other information about the lighting unit 130 and / or the LEDs 132.

[0023] The memory 134 of the lighting unit 130 can store a maximum parameter for one or more of the LEDs or other lighting elements of the lighting module 130. The maximum parameter is an indicator of one or more maximum values ​​for parameters of the LEDs 132. The maximum parameter can specify a maximum current that can be supplied to one or more LEDs 132, a maximum illuminance of one or more LEDs 132, or a duration for which one or more LEDs 132 can provide illumination in accordance with eye safety standards. As explained in more detail below, the maximum parameter can specify a proportional relationship between one or more of the previously described LED parameters or properties and / or properties of the lighting unit.For example, the maximum parameter can be a value that specifies a direct or indirect proportional relationship between an eye-safe current for an LED and an eye-safe illumination duration for an LED.

[0024] In the example shown, the lighting unit 130 is connected to the power drive 110 via a lighting connection 119. While in Fig. 1. Where the power supply for the LEDs 132 and the logical connection to the memory 134 are shown at different points, in some embodiments both connections can be contained in a single connector (e.g., a parallel connector). In some embodiments, the sets that form the lighting unit 130 can be separate lighting circuit boards. In some embodiments, the lighting connector 119 can be configured to accept one connector belonging to each lighting circuit board. In other embodiments, each lighting circuit board contains two connectors for stacking and / or daisy-chaining the lighting circuit boards. In these cases, the lighting connector 119 can be configured to accept the connector of the nearest lighting circuit board, which in turn accepts the connector of the nearest lighting circuit board, and so on.Furthermore, the lighting circuit boards are easily replaceable and can be removed from the lighting unit 130 in order to connect one or more other lighting circuit boards to the lighting unit 130.

[0025] The power driver 110 includes a processor 120 configured to adaptively control the operation of the lighting system 100. The processor 120 can be a microprocessor and / or other types of logic circuitry. For example, the processor 120 can be an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). Accordingly, the processor 120 can execute instructions to implement, for example, operations of the example procedures described herein, as illustrated in the flowcharts of the drawings accompanying this disclosure. The machine-readable instructions can be stored in the memory (e.g., volatile memory, non-volatile memory) of the processor 120 and correspond, for example, to the operations illustrated in the flowcharts of this disclosure and / or the operation of the lighting unit 130 and / or the imaging unit 140.

[0026] For example, the processor 120 can be configured to control the operation of the switches of the lighting unit 130. For this purpose, the control of the LED set switches and the control of the LED group switches can be multiplexed onto corresponding control lines connected to GPIO (General Purpose Input / Output) pins of the processor 120. Accordingly, the processor 120 is able to set the control state for the switches of the lighting unit 130 by transmitting control commands via the respective GPIO pin.

[0027] The example power drive 110 also includes a voltage controller 112 configured to boost an input voltage at a power input terminal 111 to a programmable output voltage supplied to a voltage output terminal 113. In some embodiments, the voltage controller 112 is a DC-DC step-down / step-up voltage converter. Accordingly, the voltage controller 112 includes one or more input terminals 114 through which the processor 120 controls the operation of the voltage controller 112. For example, one of the input terminals 114 can be an output voltage controller through which the processor 120 sets the output voltage supplied to the voltage output terminal 113.The processor 120 can determine a minimum capacitor voltage required to charge a storage capacitor 115 to a state of charge sufficient to power the LEDs 132 of the lighting unit 130 during a lighting cycle. Accordingly, the processor 120 can be configured to adjust the output voltage to this determined minimum capacitor voltage level. The processor 120 can control the voltage controller 112 to provide a specific voltage, current, or electrical power to each LED 132. The processor 112 can control the voltage controller 112 to supply each LED 132 with electrical energy in the form of a voltage and / or current to ensure eye-safe illumination by the lighting unit 130.

[0028] As another example, one of the input terminals 114 can correspond to a current limiting terminal, via which the processor 120 sets a maximum current flowing into the voltage controller 112. For this purpose, a power supply 105 connected to the current input terminal 111 can be assigned a maximum current rating. If the power supply 105 is, for example, a USB (Universal Serial Bus) power supply, the maximum current can be 500 mA, 900 mA, 1.5 A, or 3 A, depending on the implemented USB version. The processor 120 can control the current flowing into the voltage controller 112 according to the eye-safe operating standards for the LEDs 132 and the lighting unit.

[0029] The storage capacitor 115 is configured to store charge to power lighting cycles and / or pulses executed by the lighting unit 130. During in Fig. While the storage capacitor 115 is shown as a single capacitor in Figure 1, it can actually be a series of capacitors connected in series and / or parallel. The example lighting unit 130 is configured to draw power from the capacitor 115 (via an LED driver 122). The example storage capacitor 115 is connected to the output terminal 113 of the voltage controller 112, so that the amplified voltage drawn from the power supply 105 is used to charge the storage capacitor 115. For this purpose, the minimum capacitor voltage determined by the processor 120 can correspond to the minimum voltage level required to charge the storage capacitor 115 to a voltage level sufficient to power a subsequent lighting cycle and / or pulse.Accordingly, the storage capacitor 115 is supplied with the minimum voltage required for the operation of the lighting unit 130, thereby extending the service life of the storage capacitor 115. The voltage supplied to the storage capacitor 115 can be controlled so that the LEDs 132 are supplied with only a current or electrical power that allows for eye-safe illumination by the lighting unit 130. The capacitor 115 can be controlled to limit the period during which it supplies power to the LEDs 132 in order to keep the illumination pulses within an eye-safe time window.

[0030] The example LED driver 122 is configured to draw power from the storage capacitor 115, which is connected to a voltage input terminal 123, and to increase the capacitor voltage to a voltage level that provides a current setpoint at a current output terminal 125. For this purpose, the LED driver 122 can have an input terminal 124, via which the processor 120 sets the current setpoint of the LED driver 122. As shown, the current output terminal 125 is connected to the lighting terminal 119 to supply power to the lighting unit 130.

[0031] In the illustrated example, the LED driver 122 can be connected to a sense resistor 128 of known resistance at the current output terminal 125 to detect the output current. For this purpose, the LED driver 122 can have terminals connected to both sides of the sense resistor 128. In this way, the LED driver 122 is able to detect a voltage drop across the sense resistor 128 and compare it with the known resistance of the sense resistor 128 to determine the output current. The LED driver 122 can then ramp up the voltage supplied to the current output terminal 125 until the output current reaches the setpoint programmed by the processor 120 to provide illumination in accordance with eye safety standards.

[0032] It should be clear that the voltage drop across the LEDs 132 changes during operation due to varying lighting requirements. Therefore, the required voltage boost for proper LED operation also changes. Since conventional power supplies for lighting units provide a fixed voltage, they always deliver a lower voltage value, resulting in heat losses when less voltage is needed. In contrast, the adaptive power drive techniques described here control the power delivered to the LEDs 132 based on current demand and required eye safety standards. Thus, the LED driver 122 adaptively adjusts the voltage supplied to the LEDs (via the lighting terminal 119) based on the actual operation of the LEDs and the desired level of eye safety standards.

[0033] The processor 120 is also connected to a temperature sensor 116, which is configured to detect the temperature of the storage capacitor 115. Based on the measured temperature, the processor 120 can adjust the determined minimum capacitor voltage. The processor 120 can adjust the operation of the illumination unit 130 and / or the imaging unit 140 to give the storage capacitor 115 additional time to charge. Furthermore, the processor can configure the operation of the illumination unit 130 and / or the imaging unit 140 so that the illumination meets eye safety standards. For example, the processor 120 can control the illumination unit 130 and / or the imaging unit 140 to operate at a lower frame rate, lower current, and / or shorter pulse duration to ensure eye-safe operation.Likewise, the processor 120 can adjust the illumination cycle and / or pulse so that additional LEDs 132 of the illumination unit 130 are bypassed to ensure eye-safe operation during scanning.

[0034] The processor 120 may also include an input / output (I / O) port for data exchange with the operator device 150. For this purpose, the operator device 150 can control the operation of the industrial environment, which includes the lighting system 100. The operator device 150 may be, for example, a desktop computer, a laptop, a mobile phone, or any other computer device authorized to control the operation of the industrial environment and / or the lighting system 100. Accordingly, the operator device 150 may include a lighting design application that allows the operator to design lighting cycles to be executed by the lighting system 100.If, for example, the lighting system 100 is part of a production line for an object, the lighting cycle can configure the lighting unit 130 to provide different lighting conditions to detect various features of the object as it passes in front of the imaging unit 140. The operator device 150 can convert the lighting design into a set of lighting control instructions, which are downloaded to the processor 120 via the I / O port. Accordingly, the processor 120 can configure the lighting unit 130 (and / or its various switches) according to the lighting control instructions.The operator device 150 can enable an operator to provide desired parameter values ​​for the lighting, including, but not limited to, a desired electrical current for the LEDs, the desired number of LEDs for the lighting, specific LEDs for the lighting, the desired lighting pulse time, the lighting pulse duration, the lighting turn-on time, etc.

[0035] Furthermore, the processor 120 can send data to the operator device 150 via the I / O port. For example, the memory 134 of the lighting unit 130 can contain information about the physical and / or logical position of the LEDs 132. Accordingly, the lighting design application can provide an interface that maps the layout of the LEDs 132 for improved design control and / or simulation. As another example, the memory 134 can contain a model number for the lighting unit 130. Accordingly, the lighting design application can query a lighting unit database (not shown) to determine the position of the LED. As yet another example, the processor 120 can retrieve a maximum current for the LEDs 132 from the memory 134 to make it available to the operator device 150.The processor 120 can retrieve one or more eye-safe parameter values ​​from memory 134 to provide eye-safe lighting. Accordingly, the lighting design application can be configured to simulate the control instructions before they are loaded into the processor 120 to ensure compliance with maximum current values.

[0036] In Fig. Figure 2 shows an example of a lighting system 200, which is a modification of the lighting system 100. In particular, the example lighting system 200 includes a power controller 210, which comprises an active discharge circuit 260. The power controller 210 also includes a capacitor 215, an LED driver 222, and a processor 220, which are the storage capacitor 115, the LED driver 122, and the processor 120, respectively. Fig. 1 can act.

[0037] The active discharge circuit 260 can be configured to discharge the LED voltage (VLED) to the capacitor voltage (VCAP) to ensure eye-safe operation of the lighting unit 130. For this purpose, the processor 220 can be configured to control the lighting unit 130 to deliver successive lighting pulses with different configurations of the LEDs 132. If the voltage required to drive the LEDs 132 for eye-safe illumination decreases between successive lighting pulses, the initial, higher lighting voltage may not discharge sufficiently below the voltage level to ensure eye-safe illumination for the next, lower lighting pulse. For example, the next, lower lighting pulse might activate fewer LEDs 132 and / or operate the LEDs in a different color that requires less power (e.g., blue).B. red versus white lighting) and / or other eye safety standard values. This overvoltage can damage the LEDs 132 or cause unsafe lighting for a user or operator when the lower lighting pulse is executed. By actively discharging the overvoltage, the active discharge circuit 262 ensures safe operation of the lighting unit 130.

[0038] As shown, the active discharge circuit 260 includes an input terminal 262, which allows the processor 220 to activate the active discharge circuit 260. For example, by sending a control signal to the input terminal 262, the processor 220 closes a switch (not shown) to cause the current supplied by the LED driver 222 to flow into the active discharge circuit 260 instead of into the lighting unit 130 (via a lighting terminal, such as the lighting terminal 119 of the LED driver 222). Fig. 1) flows while capacitor 215 is being recharged. The processor 220 can thus be configured to analyze the lighting control instructions stored therein in order to detect when the voltage required for successive lighting pulses decreases, and to control the discharge circuit 260 accordingly via input terminal 262.

[0039] In Fig. Figure 3A shows an example user interface 300 for a lighting design application, which is based on an operator device 350 (such as the operator device 150 of Fig. 1) is executed. The operator device can be connected to an I / O port of a 320 processor (such as the 120 processor from Fig. 1, the 220 processor from Fig. 2A and / or another similarly configured logic circuit). As described above, the lighting design application can be configured so that an operator can design a set of lighting control instructions that specify a lighting cycle to be initiated by a lighting unit (such as the Lighting Unit 130 of the Fig. 1 and Fig. 2) is executed.

[0040] The lighting design application can be configured to query the processor 320 for information to populate the user interface 300. For example, the lighting design application can be configured to receive an LED layout from the processor 320 to present a visual display 310 of it. In some embodiments, the display of the LED layout 310 can also show the position of the LEDs relative to an object of interest. The display representing the individual LEDs in the LED layout 310 can be selected to display a corresponding LED configuration panel.

[0041] As shown, the LED configuration field can contain static information 322, which describes the selected LED, and programmable information 324. The lighting design application can retrieve the displayed information from the processor 320. Accordingly, the operator can change the programmable information 324 by selecting an interface element 334 and entering values ​​for the corresponding programmable fields. If the operator changes the pulse number field, the user interface 310 can receive new information corresponding to the new pulse. Therefore, the operator can design lighting cycles with any number of pulses via the user interface 300.

[0042] Once the operator has completed the lighting cycle design, they can interact with an operator element 332 to program the processor 320 with a set of lighting control instructions corresponding to the designed lighting cycle. Upon receiving the set of control instructions, the processor 320 can control one or more switches of the lighting unit and / or program the LEDs accordingly. In some embodiments, before downloading the set of lighting control instructions to the processor 320, the lighting design application performs a simulation of the lighting cycle to determine compliance with operating limits of the LEDs, such as a maximum current. If the simulated lighting cycle does not comply with the operating limits, the lighting application can issue a warning to the operator.The warning can indicate the specific LED that exceeds the operating limit and provide guidance on how to adjust the lighting cycle accordingly. Furthermore, the lighting design application determines whether the entered lighting cycle complies with eye safety standards. If the simulated lighting cycle is outside the operating limits, the lighting application can display a warning to the operator. Fig. Figure 3B shows the lighting design application, which issues a 360-degree warning message informing the operator that the currently requested parameter values ​​are not eye-safe and that the user should enter new parameter values ​​to ensure eye-safe lighting. The lighting design application can determine whether a requested input pulse duration, lighting intensity, pulse repetition duty cycle, or LED drive current is eye-safe. In designs using multiple color LEDs or lighting elements, the requested input can be a desired color or colors of the lighting. Therefore, the lighting design application can also include interfaces for a user to input the desired colors or color groups. For example, a user can enter a desired lighting wavelength or a band of lighting wavelengths as the requested input.

[0043] Fig. Figure 4 is a flowchart of a procedure 400 for controlling lighting according to eye safety standards. The flowchart can be generated by a processor of a lighting system (such as processor 120, 220, or 320 of the Fig. 1, Fig. 2 or 3 and / or another similarly configured logic circuit). As an example, procedure 400 of Fig. 4 with reference to elements of Fig. 1 described in more detail.

[0044] In block 402, processor 120 is switched on. In particular, processor 120 can be connected to a power supply (such as power supply 105 of Fig. 1) be connected, e.g. by closing a switch assigned to the power supply.

[0045] In block 404, processor 120 accesses the memory 134 of lighting unit 130 and retrieves device information specifying the properties of lighting unit 130. The retrieved device information includes a variety of parameters for one or more lighting elements of the lighting module. Such lighting elements can include one or more LEDs, such as LEDs 132. The device information can include a category voltage for LEDs 132, a category current for LEDs 132, a category temperature for LEDs 132, a number of LEDs 132, an LED color for LEDs 132, an LED binning configuration for LEDs 132, an LED grouping arrangement (e.g., a logical positioning of LEDs 132 with respect to set and group numbering), and a physical arrangement (e.g., a physical layout).a physical position of the LEDs 132 on the lighting unit 130), relative positions of the LEDs 132 to each other, an LED part number, a physical position and / or orientation of one or more LEDs on a printed circuit board, an eye-safe current for each of the LEDs 132, an eye-safe power for each of the LEDs 132, an eye-safe illumination output for each of the LEDs 132, a printed circuit board identification number, a printed circuit board type, sensor information (i.e., temperature or other types of sensors), a model number for the lighting unit 130, and / or other information about the lighting unit 130 and / or the LEDs 132.

[0046] The device information also includes a maximum constant for at least one lighting element (e.g., for an LED). This maximum constant specifies a relationship between at least two parameters of the lighting element. Furthermore, the maximum constant indicates eye-safe operation of the lighting unit 130 or a radiation risk group. The eye safety standard used by the system 100 may, for example, correspond to the standards and parameter values ​​specified in the international standards IEC 62471:2006 (Ed. 1) or EN 62471:2008. Other eye safety standards may also be used, or eye safety standards that are updated over time may also be used. Values ​​and parameter limits according to the eye safety standards can be stored in memory 134, and the maximum constant is an indicator of one or more of the parameter limits.

[0047] The maximum constant can indicate a proportional relationship between the electrical LED driver current and the illumination pulse duration of an LED. For example, an equation can be derived to determine the maximum constant, which reads as follows. K=I*t / T, where K is the maximum eye safety constant, I is the LED drive current, t is the duration of an illumination pulse, and T is the reciprocal of the frame rate of a camera such as image sensor 142. K is a constant value, and the frame rate of a system can also be a constant or fixed value, while both the pulse duration and the drive current can be varied depending on the desired illumination. While the drive current and pulse duration are used in the present example, the maximum constant can specify a relationship between other illumination and device parameters, such as an electrical drive current, an illumination output power, a luminous intensity (i.e., candela), a luminous flux (i.e., lumens), or a total illumination time that an LED can illuminate, among other operating parameters for the illumination.

[0048] In block 406, the procedure involves receiving a desired parameter value from a user for one of the parameters from the set of available parameters. In the current example, the user can enter a desired value for the illumination pulse duration.

[0049] In block 408, processor 120 determines a test constant based on the desired parameter value. The test constant is a value for K, here represented as K. test , denotes a value that can be used to determine whether the entered desired parameter value is within eye safety standards. For example, a current of 2 mA may be required to operate an LED, the frame rate of a sensor may be 60 frames per second, resulting in a value of T = 1 / 60, and a user may enter a desired parameter value of 2 ms for the pulse duration. This yields a value for the test constant K. test = 0.066.

[0050] In block 410, processor 120 compares the test constant and the maximum constant to determine whether the desired parameter value is acceptable according to eye safety standards. For example, the maximum constant K for a particular lighting unit or device, such as a green LED, might be 0.1. In this example, the user has entered a desired pulse duration of 2 ms, resulting in a test constant of 0.066, which is below the maximum constant of 0.1. Therefore, processor 120 compares the test constant and the maximum constant and determines that the desired input parameter value of 2 ms pulse duration is within eye safety standards and is acceptable. If the user then changes the desired input value to 4 ms pulse duration, the test constant would be 0.13.In block 410, the processor 120 compares the test constant with the maximum constant and determines that the test constant exceeds the maximum constant and that the desired parameter value of 4 ms is not eye-safe and therefore not an acceptable value.

[0051] While the comparison of the maximum constant and the test constant is described here, the Processor 120 can also determine an acceptable value for the desired input and compare the desired input value with the determined acceptable value of this parameter. For example, based on the maximum constant, the Processor 120 can determine that the maximum current that may be supplied to an LED is 2 mA. The user can then enter a desired parameter value of 2.5 mA, and the Processor 120 can compare these two values ​​to determine eye-safe operation during a lighting cycle. As another example, the desired parameter value could be a desired lighting level.The Processor 120 can then determine the test constant as the test illumination time, and the multitude of parameters of the illumination element includes a total illumination time, which specifies the duration the illumination element can be lit during a given period. The Processor 120 then determines the test illumination time from the desired illumination value and the maximum constant. The Processor 120 compares the test illumination time and the total illumination time and determines that the desired illumination value is an acceptable value if the test illumination time is equal to or less than the total illumination time, or that the desired illumination value is not an acceptable value if the test illumination time is greater than the total illumination time.Furthermore, the desired parameter value can be a desired illumination time, and the described procedure can be carried out by determining a test constant as the test illumination quantity and comparing a test illumination quantity with a maximum permissible illumination quantity.

[0052] If the processor 120 determines that the desired parameter value is not within the eye safety standards, the processor 120 can provide a notification to the user or operator. For example, the processor 120 can issue a notification via the lighting design application 300 that the current set of parameter values ​​is not eye safe. In block 414, the procedure includes requesting a new desired parameter value. For example, the processor 120 can issue a message that a shorter pulse duration is required to meet the eye safety standards. A user can then input a different value via the operator device 150, and the procedure 400 can then recalculate a new test constant and determine whether the new desired parameter value is within the eye safety standards.

[0053] In some cases, the user may choose not to change the desired parameter to an eye-safe value. In such cases, the processor 120 either shortens the pulse length (e.g., in the case of a global shutter sensor) or reduces the current supplied to the lighting elements, such as the LEDs 132 (e.g., in the case of a roller shutter sensor). The processor 120 can provide the changed parameter values ​​during the execution of a lighting cycle or change the value and inform an operator via the operator device 150.

[0054] Alternatively, if processor 120 determines that the desired parameter is within the eye safety standards, processor 120 configures an LED driver in block 412 (like LED drivers 122 and 222 of the Fig. 1 or 2) to provide the driver current according to the determined eye-safe pulse duration. For this purpose, the processor 120 can send a control signal to an input terminal of the LED driver, which controls the LED driver to use the desired parameter values ​​as the current output for the LEDs.

[0055] The Processor 120 can also control the LED sets according to the determined eye-safe parameters. The Processor 120 can configure the LEDs according to the defined eye-safe lighting cycle. To this end, the processor can issue a series of control instructions via one or more GPIO pins to control switches connected to the LED sets and / or groups of LEDs within the LED sets. For example, the processor can transmit control signals via the GPIO pins, implementing multiplexing techniques, to signal the control state for the switches of the LED sets and / or LED groups. Additionally, the Lighting Unit 130 can contain color-programmable LEDs, and the processor can be configured to also set the LED color.After setting the lighting unit's switches and LED colors, the processor can close a switch to connect the lighting unit to the LED driver. Furthermore, the LED's color can change the eye-safe driver current, lighting pulse duration, pulse repetition period, or other values ​​of a specific LED. Therefore, the procedure can be 400 of... Fig. 4. This should be performed every time a user changes the desired color of an LED to determine whether the parameters of the lighting cycle for a particular color of an LED are eye-safe.

[0056] The above description refers to possible embodiments in the accompanying drawings. Alternative embodiments of the examples shown in the drawings include one or more additional or alternative elements, methods, and / or devices. Additionally or alternatively, one or more of the example blocks in the diagrams may be combined, split, rearranged, or omitted. The components represented by the blocks in the diagrams are implemented by hardware, software, firmware, and / or any combination thereof. In some examples, at least one of the components represented by the blocks is implemented by a logic circuit. As used herein, the term "logic circuit" is expressly defined as a physical device containing at least one hardware component configured (e.g.,Logic circuits are designed to control one or more machines (by operating according to a predetermined configuration and / or by executing stored machine-readable instructions) and / or to perform operations on one or more machines. Examples of logic circuits include one or more processors, one or more coprocessors, one or more microprocessors, one or more controllers, one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), one or more microcontroller units (MCUs), one or more hardware accelerators, one or more special-purpose computer chips, and one or more system-on-a-chip (SoC) devices. Some example logic circuits, such as ASICs or FPGAs, are specially configured hardware for performing operations (e.g.,one or more of the operations described herein and illustrated in the flowcharts of this disclosure, if any). Some example logic circuits are hardware that executes machine-readable instructions to perform operations (e.g., one or more of the operations described herein and illustrated by the flowcharts of this disclosure, if any). Some example logic circuits comprise a combination of specially configured hardware and hardware that executes machine-readable instructions. The above description refers to various operations described herein and flowcharts that may be appended to illustrate the sequence of these operations. All such flowcharts are representative of the example procedures disclosed herein. In some examples, the procedures illustrated by the flowcharts implement the devices represented by the block diagrams.Alternative implementations of the example methods disclosed herein may include additional or alternative operations. Furthermore, operations of alternative implementations of the methods disclosed herein may be combined, split, rearranged, or omitted. In some examples, the operations described herein are implemented by machine-readable instructions (e.g., software and / or firmware) stored on a medium (e.g., an accessible machine-readable medium) for execution by one or more logic circuits (e.g., processor(s)). In some examples, the operations described herein are implemented by one or more configurations of one or more custom-designed logic circuits (e.g., ASIC(s)). In some examples, the operations described herein are implemented by a combination of custom-designed logic circuits and machine-readable instructions stored on a medium (e.g.,(stored on an accessible, machine-readable medium) for execution by logic circuits, implemented.

[0057] As used herein, each of the terms “accessible machine-readable medium”, “non-transient machine-readable medium”, and “machine-readable storage device” is expressly defined as a storage medium (e.g., a disk of a hard disk drive, a digital versatile disc, a compact disc, flash memory, read-only memory, random access memory, etc.) on which machine-readable instructions (e.g., program code in the form of, for example, software and / or firmware) are stored for any suitable duration (e.g., permanently, for a longer period (e.g., during the execution of a program associated with the machine-readable instructions), and / or for a short period (e.g., during the temporary storage of the machine-readable instructions and / or during a buffering process)).Furthermore, the terms "accessible, machine-readable medium," "non-transitory, machine-readable medium," and "machine-readable storage device" are expressly defined here in such a way as to exclude the transmission of signals. That is to say, none of the terms "accessible, machine-readable medium," "non-transitory, machine-readable medium," and "machine-readable storage device," as used in the claims of this patent, can be interpreted as being implemented by a propagating signal.

[0058] Certain embodiments have been described in the foregoing description. However, it is clear to a person skilled in the art that various modifications and changes can be made without deviating from the scope of the invention as set forth in the claims below. Accordingly, the description and the figures are to be understood as illustrative rather than limiting, and all such modifications are to be included within the scope of the present teachings. Furthermore, the described embodiments / examples / implementations are not to be understood as mutually exclusive, but rather as potentially combinable if such combinations are in any way permissive. In other words, any feature disclosed in one of the aforementioned embodiments / examples / implementations may be included in any of the other aforementioned embodiments / examples / implementations.

[0059] The benefits, advantages, solutions to problems, and all elements that may lead to the occurrence or enhancement of a benefit, advantage, or solution are not to be understood as critical, necessary, or essential features or elements in some or all of the claims. The invention is defined solely by the attached claims, including any amendments made during the pendency of this application and all equivalents of the granted claims.

[0060] Furthermore, in this document, relational terms such as first and second, upper and lower, and the like may be used merely to distinguish one entity or action from another, without necessarily requiring or implying any actual relationship or order of such an entity or action between such entities or actions. The expressions "includes," "comprising," "has," "have," "exhibits," "exhibiting," "contains," "containing," or any other variation thereof are intended to cover non-exclusive inclusion, such that a process, procedure, product, or device that includes, has, exhibits, or contains a list of elements may not only have those elements but may also have other elements not expressly listed or inherent in such process, procedure, product, or device. An element that "includes," "has," "exhibits," or "contains"The use of the term "a" does not, without further limitations, preclude the existence of additional identical elements in the process, method, product, or device that comprises, has, features, or contains the element. The terms "a" and "a" are defined as one or more unless expressly stated otherwise herein. The terms "essentially," "generally," "approximately," "about," or any other version thereof are defined in such a way as to be understood by a person skilled in the art in this field, and in one non-restrictive embodiment, the expression is defined as within 10%, in another embodiment as within 5%, in yet another embodiment as within 1%, and in yet another embodiment as within 0.5%. The term "coupled," as used herein, is defined as connected, but not necessarily directly and not necessarily mechanically.A device or structure that is “configured” in a certain way is at least also configured in that way, but may also be configured in ways that are not listed.

[0061] The summary of the disclosure is provided to enable the reader to quickly ascertain the essence of the technical disclosure. It is provided with the understanding that it is not intended to be used for interpreting or limiting the scope or meaning of the claims. Furthermore, it can be inferred from the preceding detailed description that various features in different embodiments have been summarized for the purpose of streamlining the disclosure. This type of disclosure is not to be interpreted as reflecting the intention that the claimed embodiments require more features than are expressly stated in each claim. Rather, as the following claims demonstrate, the inventive step lies in fewer than all the features of a single disclosed embodiment.The following claims are hereby incorporated into the detailed description, each claim being a separately claimed subject matter.

Claims

[1] Method for controlling a lighting system, the method comprising Retrieving, by a processor (120) and from a memory (134) of a lighting module (130), device information indicating properties of the lighting module (130), wherein the device information comprises (i) a plurality of parameters of a lighting element of the lighting module (130) and (ii) a maximum constant for the lighting element, wherein the maximum constant indicates a relationship between at least two parameters of the lighting element; Received from a user a desired parameter value for one of the parameters from the multitude of parameters; Determine, by the processor (120), a test constant from the desired parameter value; Determine, using the processor (120) and from the test constant and the maximum constant, that the desired parameter value is an acceptable parameter value; and Control of a power source by the processor (120) to provide electrical current to the lighting module (130) according to the desired parameter value; where the maximum constant also indicates a radiation risk group classification. [2] Method according to claim 1, wherein the maximum constant indicates a proportional relationship between an electric current of the lighting element and an output illumination provided by the lighting element, and wherein the test constant indicates one of (i) a desired electric current of the lighting element or (ii) an output illumination provided by the lighting element. [3] The method of claim 1, wherein determining that the desired parameter value is an acceptable parameter value comprises: Comparing the test constant and the maximum constant by the processor (120); and Determine, by the processor (120), that the desired parameter value is an acceptable parameter value if the test constant is equal to or less than the maximum constant, or that the desired parameter value is not an acceptable parameter value if the test constant is greater than the maximum constant. [4] Method according to claim 1, wherein the desired parameter value is a desired illumination value, the test constant is a test illumination time, and the plurality of parameters of the illumination element comprises a total illumination time that specifies a time amount for which the illumination element can provide illumination over a given time period, and wherein the method further comprises: Determine, by the processor (120), a test illumination time from the desired illumination value and the maximum constant; Compare, by the processor (120), the test illumination time and the total illumination time; and Determine, by the processor (120), that the desired illumination value is an acceptable illumination value if the test illumination time is equal to or less than the total illumination time, or that the desired illumination value is not an acceptable illumination value if the test illumination time is greater than the total illumination time. [5] Method according to claim 1, wherein the desired parameter value is a desired illumination time, the test constant is a test illumination value, and the plurality of parameters of the illumination element includes a maximum illumination value that specifies an amount of illumination that the illumination element can provide, and wherein the method further comprises: Determine, by the processor (120), a test illumination value from the desired illumination time and the maximum constant; Compare, by the processor (120), the test illumination value and the maximum illumination value; and Determine, by the processor (120), that the desired illumination time is an acceptable illumination time if the test illumination value is equal to or less than the maximum illumination value, or that the desired illumination time is not an acceptable illumination time if the test illumination value is greater than the maximum illumination value. [6] Method according to claim 1, wherein the lighting module (130) comprises one or more light-emitting diodes (LEDs) (132). [7] Method according to claim 1, wherein the device information comprises at least one of: a printed circuit board identifier, one or more properties of light-emitting diodes (LEDs), a printed circuit board type, identifiers of sensor types of the lighting module (130), a lighting module identifier. [8] Method according to claim 7, wherein the one or more LED properties comprise a color of an LED (132), a physical grouping of LEDs (132), relative positions of LEDs (132) to each other, positions of LEDs (132) on a printed circuit board, an LED part number, a maximum current for an LED (132), a number of LEDs (132), a physical position of an LED (132) on the lighting module (130) and a physical orientation of an LED (132) on the lighting module (130). [9] Method according to claim 1, further comprising determining, by the processor (120), a maximum value of another parameter from the desired parameter value and the maximum constant. [10] Lighting system (100), comprising: a lighting connection (119) adapted to accommodate a lighting module (130) comprising (i) one or more lighting elements and (ii) a memory (134) storing device information displayed by the lighting module (130), wherein the device information comprises (i) a plurality of parameters of a lighting element of the lighting module (130) and (ii) a maximum constant for the lighting element, the maximum constant indicating a relationship between at least two parameters of the lighting element; at least one processor (120) that is operationally connected to the lighting port (119), wherein the processor (120) is configured to: to retrieve the device information from the memory (134) of the lighting module (130); to receive a desired parameter value for one of the parameters from a multitude of parameters at a user interface; to determine a test constant from the desired parameter value; to determine from the test constant and the maximum constant that the desired parameter value is an acceptable parameter value; and to control a power source to supply electrical current to the lighting module (130) according to the desired parameter value; where the maximum constant also indicates a radiation risk group classification. [11] Lighting system (100) according to claim 10, wherein the lighting module (130) is selectively removable from the lighting system (100). [12] Lighting system (100) according to claim 10, wherein the maximum constant specifies a proportional relationship between an electric current of the lighting element and an output illumination provided by the lighting element, and wherein the test constant specifies one of (i) a desired electric current of the lighting element or (ii) an output illumination provided by the lighting element. [13] Lighting system (100) according to claim 10, wherein the processor (120) is further configured to determine that the desired parameter value is an acceptable parameter value: to compare the test constant and the maximum constant; and to determine that the desired parameter value is an acceptable parameter value if the test constant is equal to or less than the maximum constant, or that the desired parameter value is not an acceptable parameter value if the test constant is greater than the maximum constant. [14] Lighting system (100) according to claim 10, wherein the desired parameter value is a desired lighting value, the test constant is a test lighting time, and the plurality of parameters of the lighting element includes a total lighting time that specifies a time amount for which the lighting element can provide lighting over a given time period, and wherein the processor (120), in order to determine that the desired parameter value is an acceptable parameter value, is further configured to: to determine a test illumination time from the desired illumination value and the maximum constant; to compare the test illumination time and the total illumination time; and to determine that the desired illumination value is an acceptable illumination value if the test illumination time is equal to or greater than the total illumination time, or that the desired illumination value is not an acceptable illumination value if the test illumination time is less than the total illumination time. [15] Lighting system (100) according to claim 10, wherein the desired parameter value is a desired lighting time, the test constant is a test lighting value, and the plurality of parameters of the lighting element includes a maximum lighting value that specifies an amount of lighting that the lighting element can provide, and wherein the processor (120), in order to determine that the desired parameter value is an acceptable parameter value, is further configured to: to determine a test illumination value from the desired illumination time and the maximum constant; to compare the test illumination value and the maximum illumination value; and to determine that the desired illumination time is an acceptable illumination time if the test illumination value is equal to or greater than the maximum illumination value, or that the desired illumination time is not an acceptable illumination time if the test illumination value is less than the maximum illumination value. [16] Lighting system (100) according to claim 10, wherein the lighting module (130) comprises one or more light-emitting diodes (LEDs) (132). [17] Lighting system (100) according to claim 10, wherein the device information comprises at least one of: a printed circuit board identifier, one or more properties of light-emitting diodes (LEDs) (132), a printed circuit board type, identifiers of sensor types of the lighting module (130), a lighting module identifier. [18] Lighting system (100) according to claim 17, wherein the one or more LED properties comprise a color of an LED (132), a physical grouping of LEDs (132), relative positions of LEDs (132) to each other, positions of LEDs (132) on a printed circuit board, an LED part number, a maximum current for an LED (132), a number of LEDs (132), a physical position of an LED (132) on the lighting module (130), a physical orientation of an LED (132) on the lighting module (130). [19] Lighting system (100) according to claim 10, wherein the processor (120) is further configured to determine a maximum value of another parameter from the desired parameter value and the maximum constant.

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