Algorithm Control of LED Current and On-Time for Eye Safety

Abstract

A method and system for controlling lighting in accordance with eye safety standards, the method comprising: retrieving, by a processor, device information from a memory of a lighting module, the device information being indicative of a characteristic of the lighting module, the device information including a plurality of parameters of lighting elements of the lighting module and a maximum constant for the lighting elements, the maximum constant being associated with a desired eye safety standard and indicative of a relationship between at least two parameters of the lighting elements, the method further comprising receiving, from a user, a desired parameter value for one of the plurality of parameters, the processor determining a test constant from the desired parameter value, and comparing the test constant to the maximum constant to determine whether the desired parameter value is an acceptable value.

Description

Background Art

[0001] Typical barcode readers and machine vision systems, such as handheld barcode readers, POS scanners, direct part marking scanners, etc., require appropriate illumination of the target in order to obtain a high-quality, "unblurred" image for decoding the barcode in the image. The illumination source is essential for decoding the barcode in the captured image, and various factors such as time, illumination direction, illumination intensity, light color, light type, light source type, etc. affect how effective the system can be in decoding the barcode. Furthermore, the barcode type, target reflectivity, target distance or size are all important factors in decoding the barcode in the captured image, and different types of illumination may be required depending on each type.

[0002] In an illumination system, it is important to maintain eye-safe illumination and operation. Manufacturers of various illumination systems want to operate their systems within a given risk group in accordance with eye safety standards. Maintaining eye-safe operation across multiple systems can be complex because different light sources (LEDs, laser diodes, etc.) have different eye safety risks and standards depending on factors such as light coherence and spectrum. Furthermore, each color of illumination has different risk factors. This makes systems that maintain eye safety across various colors of LEDs and multi-color illumination sources even more complex. For example, an illumination system using blue LEDs generally has a higher risk of eye damage, while green or red LEDs in the same illumination system can operate within the eye safety standards if they have the same current and output illumination level. Therefore, it can be beneficial to control individual light sources to maintain compliance of the entire system with the desired eye safety standards during operation.

Summary of the Invention

[0003] In one embodiment, the present invention is a method for controlling illumination according to a desired eye safety standard. The method comprises a step of obtaining, by a processor, from a memory of an illumination module, device information indicating characteristics of the illumination module. The device information includes (i) a plurality of parameters of an illumination element of the illumination module and (ii) a maximum constant for the illumination element, the maximum constant indicating a relationship between at least two parameters of the illumination element. The method further comprises a step of receiving, from a user, a desired parameter value for one of the plurality of parameters. The processor determines a test constant from the desired parameter value and determines whether the desired parameter value is an acceptable parameter value from the test constant and the maximum constant.

[0004] In a variation of this embodiment, the maximum constant indicates a proportional relationship between the current of the illumination element and the output illuminance provided by the illumination element, and the test constant indicates either (i) a desired current of the illumination element or (ii) an output illuminance provided by the illumination element.

[0005] In another variation of this embodiment, the step of determining that the desired parameter value is an acceptable parameter value includes a step of comparing, by the processor, the test constant and the maximum constant, and a step of determining, by the processor, that the desired parameter value is an acceptable parameter value if the test constant is less than or equal to the maximum constant, or determining that the desired parameter value is not an acceptable parameter value if the test constant is greater than the maximum constant.

[0006] In another embodiment, the present invention is an illumination system comprising an illumination port adapted to receive an illumination module having (i) one or more illumination elements and (ii) a memory for storing device information. The device information indicates the illumination module and includes (i) a plurality of parameters of the illumination elements of the illumination module and (ii) a maximum constant for the illumination elements, the maximum constant indicating a relationship between at least two parameters of the illumination elements. The system further comprises at least one processor operably connected to the illumination port, the processor being configured to obtain the device information from the memory of the illumination module, receive a desired parameter value for one of the plurality of parameters at a user interface, determine a test constant from the desired parameter value, determine from the test constant and the maximum constant whether the desired parameter value is an acceptable parameter value, and control a power source to provide current to the illumination module according to the desired parameter value.

[0007] In a variation of this embodiment, the illumination module is selectively removable from the illumination system.

[0008] In another variation of this embodiment, the maximum constant indicates a proportional relationship between the current of the illumination element and the output illuminance provided by the illumination element, and the test constant indicates either (i) a desired current of the illumination element or (ii) an output illuminance provided by the illumination element.

[0009] In yet another variation of this embodiment, to determine whether 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 less than or equal to the maximum constant, or determine that the desired parameter value is not an acceptable parameter value if the test constant is greater than the maximum constant.

[0010] The accompanying drawings, together with the following detailed description, are incorporated in and form a part of this specification, and serve to further explain embodiments of the concepts including the claimed invention, and to explain various principles and advantages of those embodiments. In the accompanying drawings, like reference numerals refer to the same or functionally similar elements throughout the separate drawings.

Brief Description of the Drawings

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Figure 1

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Figure 3A

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Figure 3B

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Best Mode for Carrying Out the Invention

[0016] Those skilled in the art will understand that the elements in the drawings are shown simply and clearly, and are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be exaggerated compared to other elements to assist in improving the understanding of the embodiments of the present invention.

[0017] The components of the apparatus and method are, where appropriate, indicated by conventional reference numerals 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 of details, and the disclosure of such details will be readily apparent to those skilled in the art who benefit from the description herein.

[0018] A scanning system requires appropriate illumination of the target in order to decode various types of targets. The illumination system can be designed to illuminate a specific target having specific characteristics. For example, one illumination system can be used to illuminate and scan a target within a narrow field of view at a distance from the scanning system, and another illumination system can be used to scan a target within a wider field of view in a range closer to the scanning system. Therefore, it is desirable for the system to include a modular illumination system that is attached to an illumination port or bay and allows the illumination module to be changed based on the type of scanning target.

[0019] The illumination system uses various illumination sources, such as LEDs, having various colors, various currents, and various power specifications. Further, for the safe operation of the illumination system, various light sources (including focusing of the diffractive optical system coupled thereto) need to meet the eye safety standards. A system and method for determining the eye-safe operation of a given illumination module are described. The method includes automatic control of the current and on / off time of individual illumination sources and allows eye-safe operation in a wide range of illumination modules using one or more illumination sources.

[0020] Figure 1 shows an exemplary lighting system (100) implementing the eye safety lighting technology disclosed in this specification. In Figure 1, the current supply path for the lighting unit is illustrated by thicker lines, and the control connection lines are illustrated by thinner lines. The lighting system 100 can be implemented in an industrial environment. For example, the lighting system 100 can be implemented in an assembly line to detect barcodes placed on parts and / or to detect defects on parts. As shown, there are three main components of the lighting system 100, namely, an imaging unit 140 configured to capture image data, a lighting unit 130 configured to provide illumination light to facilitate the capture of the image data, and a power driver 110 configured to provide power to the lighting unit 130.

[0021] Starting with the description of the imaging unit 140, the imaging unit 140 can include a camera or a wide-angle camera and can include any known imaging device for capturing image data. For example, the imaging unit 140 can include an array of image sensors 142 configured to detect the reflection of light passing through an optical system. In some embodiments, the imaging unit 140 includes one or more filters configured to filter the reflected light before and / or after being sensed by the image sensor 142.

[0022] Turning to the illumination unit 130, the illumination unit 130 includes one or more LEDs 132 and a memory 134. In the illustrated embodiment, the illumination unit 130 includes four banks of LEDs 132 (132a - 132h) separated into two groups. Each of the banks may include a switch associated therewith to controllably prevent current from flowing through the respective LEDs 132 within the bank. For example, the switch associated with bank 1 may prevent current from flowing through LED groups 132a, 132b. Similarly, each of the LED groups may be associated with a switch for controllably bypassing the current flowing within the LED bank to control the LED groups (132a - 132h). It should be understood that the switch need not be a physical switch such as a relay and may instead be an electrical switch implemented via a transistor. Further, the switch may include elements for controlling the amount of current provided to each LED group 132a - 132h to control the amount of illumination provided by the corresponding LEDs of the LED groups 132a - 132h.

[0023] The memory 134 of the illumination unit 130 may be configured to store various information regarding the LEDs 132 or LED characteristics. For example, the memory 134 may store the category voltage of the LEDs 132, the category current of the LEDs 132, the category temperature of the LEDs 132, the number of LEDs 132, the LED color of the LEDs 132, the LED binning of the LEDs 132, the arrangement of the LED groups (e.g., the logical positioning of the LEDs 132 with respect to the numbering of the banks and groups), the physical arrangement (e.g., the physical position of the LEDs 132 on the illumination unit 130), the relative positions of the LEDs 132 to each other, the part numbers of the LEDs, the physical position and / or orientation of one or more LEDs on the circuit board, the eye-safe current for each of the LEDs 132, the eye-safe power to be provided to each of the LEDs 132, the eye-safe illumination output for each of the LEDs 132, the model number of the illumination unit 130, and / or other information regarding the illumination unit 130 and / or the LEDs 132.

[0024] The memory 134 of the lighting unit 130 may store the maximum parameters of one or more LEDs or other lighting elements of the lighting module 130. The maximum parameters indicate one or more maximum values of the parameters of the LEDs 132. The maximum parameters may indicate the maximum current that can be provided to one or more LEDs 132, the maximum lighting output of one or more LEDs 132, and the amount (length) of time that one or more LEDs 132 can provide lighting, in accordance with eye safety standards. As will be described in more detail below, the maximum parameters may indicate a proportional relationship between one or more of the aforementioned LED parameters or characteristics and / or characteristics of the lighting unit. For example, the maximum parameter may be a value indicating a direct or indirect proportional relationship between the eye-safe current of the LED and the amount (length) of eye-safe lighting time of the LED.

[0025] In the illustrated example, the lighting unit 130 is connected to the power driver 110 via the lighting port 119. FIG. 1 illustrates the current supply to the LEDs 132 and the logical connection to the memory 134 occurring at different points, but in some embodiments, both connections may be included within a single connector (e.g., a parallel port connector). It should be understood that in some embodiments, the plurality of banks forming the lighting unit 130 may be separate lighting substrates. In some implementations of this embodiment, the lighting port 119 may be configured to receive a connector associated with each lighting substrate. In other implementations, each lighting substrate includes two connectors for stacking and / or daisy-chaining the lighting substrates together. In these implementations, the lighting port 119 may be configured to receive a connector from the nearest lighting substrate and then receive a connector from the next nearest lighting substrate. Further, it can be understood that the lighting board is easily replaceable, can be removed from the lighting unit 130, and one or more other lighting boards can be connected to the lighting unit 130.

[0026] Turning to the description of the power drive device 110, the power drive device 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 circuits. For example, the processor 120 can be a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). Therefore, the processor 120 can be executable to execute instructions for implementing the operations of the exemplary methods described herein, as may be represented by the flowcharts of the drawings accompanying this specification. Machine-readable instructions can be stored in the memory of the processor 120 (e.g., volatile memory, non-volatile memory), and correspond to, for example, the operations represented by the flowcharts of the present disclosure and / or the operations of the lighting unit 130 and / or the imaging unit 140.

[0027] For example, the processor 120 can be configured to control the operation of the switch of the lighting unit 130. In this regard, the control of the switch of the LED bank and the control of the switch of the LED group can be multiplexed on respective control lines connected to the general purpose input / output (GPIO) ports of the processor 120. Therefore, the processor 120 can set the control states for the plurality of switches of the lighting unit 130 by sending control commands through the respective GPIO ports.

[0028] Exemplary power drive device 110 also includes a voltage controller 112 configured to boost (step up) the input voltage of power input port 111 to a programmable output voltage supplied to voltage output port 113. In some embodiments, voltage controller 112 is a DC-DC buck-boost voltage converter. Accordingly, voltage controller 112 includes one or more input ports 114 through which processor 120 controls the operation of voltage controller 112. For example, one of input ports 114 can be for output voltage control, through which processor 120 sets the output voltage supplied to voltage output port 113. Processor 120 can determine the minimum capacitor voltage required to recharge storage capacitor 115 to a charge level that satisfies the power requirements for the operation of LED 132 of lighting unit 130 during the lighting cycle. Accordingly, processor 120 can be configured to set the output voltage to this determined minimum capacitor voltage level. Processor 120 can control voltage controller 112 such that voltage controller 112 provides a specific voltage, current, or power to each LED 132. Processor 112 can control voltage controller 112 to provide power in the form of voltage and / or current to each LED 132 to provide eye-safe lighting from lighting unit 130.

[0029] As another example, one of input ports 114 can correspond to a current limit port, through which processor 120 sets the maximum current flowing through voltage controller 112. In this regard, power source 105 connected to power input port 111 can be associated with a maximum current rating. For example, if power source 105 is a universal serial bus (USB) power source, the maximum current can be 500 mA, 900 mA, 1.5 A, or 3 A, depending on the USB version implemented. Processor 120 can control the current flowing through voltage controller 112 in accordance with the eye-safe operating criteria of LED 132 and the lighting unit.

[0030] The storage capacitor 115 is configured to store charge for powering the lighting cycle and / or its pulses executed by the lighting unit 130. Although FIG. 1 illustrates the storage capacitor 115 as a single capacitor, the storage capacitor 115 can be a bank of capacitors connected in series and / or parallel to each other. The exemplary lighting unit 130 is configured to draw power from the capacitor 115 (via the LED driver 122). The exemplary storage capacitor 115 is connected to the output port 113 of the voltage controller 112 such that the voltage drawn from the power supply 105 and boosted is used to recharge the storage capacitor 115. In this regard, the minimum capacitor voltage determined by the processor 120 can correspond to the minimum voltage level for recharging the storage capacitor 115 to a voltage level sufficient to power subsequent lighting cycles and / or their pulses. Accordingly, the storage capacitor 115 is exposed only to the minimum voltage (only) required for the operation of the lighting unit 130, thereby extending the life of the storage capacitor 115. The voltage supplied to the storage capacitor 115 can be controlled to supply only the amount of current or power necessary to provide eye-safe lighting to the LED 132 from the lighting unit 130. The capacitor 115 can be controlled to limit the amount (length) of time the capacitor 115 provides power to the LED 132 to maintain the lighting pulse within an eye-safe time window.

[0031] The exemplary LED driver 122 is configured to draw power from the storage capacitor 115 connected to the voltage input port 123 and boost the capacitor voltage to a voltage level that supplies a current setpoint value at the current output port 125. In this regard, the LED driver 122 can include an input port 124 through which the processor 120 can set the current setpoint value of the LED driver 122. As shown, the current output port 125 is connected to the lighting port 119 to supply power to the lighting unit 130.

[0032] In the illustrated example, to detect the output current at the current output port 125, the LED driver 122 can be connected to a sense resistor 128 having a known resistance. In this regard, the LED driver 122 can include ports operably connected on both sides of the sense resistor 128. Thereby, the LED driver 122 can determine the voltage drop across the sense resistor 128 for comparison to the known resistance of the sense resistor 128. Next, the LED driver 122 can raise the voltage supplied to the current output port 125 until the output current reaches the current set point programmed by the processor 120 to provide illumination according to eye-safe criteria.

[0033] During operation, it should be understood that the voltage drop across the LED 132 varies due to different lighting needs. Accordingly, the voltage boost requirements for proper operation of the LED also vary. Traditional power drivers for lighting assemblies supply a constant voltage, so traditional power drivers always provide the worst-case voltage level and cause heat dissipation even when a lower voltage is required. Instead, the adaptive power drive techniques described herein control the power supplied to the LED 132 based on the current requirements and the required eye-safe criteria. Thereby, the LED driver 122 adaptively adjusts the voltage supplied to the LED (via the lighting port 119) based on the actual operation of the LED and the desired level of eye-safe criteria. Accordingly, less excess power is dissipated as heat.

[0034] Processor 120 is also connected to a temperature sensor 116 configured to sense the temperature of the storage capacitor 115. Based on the sensed temperature, processor 120 may adjust the determined minimum capacitor voltage. Processor 120 may adjust the operation of the illumination unit 130 and / or the imaging unit 140 to provide additional time for the storage capacitor 115 to recharge. Additionally, processor 120 may adjust the operation of the illumination unit 130 and / or the imaging unit 140 to provide illumination that complies with eye-safe criteria. For example, processor 120 may control the illumination unit 130 and / or the imaging unit 140 to operate at a lower current, and / or with a shorter pulse duration, and / or to operate at a slower frame rate so as to provide eye-safe operation. Similarly, processor 120 may adjust the illumination cycle and / or pulse to bypass additional LEDs 132 of the illumination unit 130 so as to provide eye-safe operation during scanning.

[0035] Processor 120 may also include an input / output (I / O) port for exchanging data with operator device 150. In this regard, operator device 150 may control the operation of the industrial environment including lighting system 100. For example, operator device 150 may be a workstation computer, a laptop, a mobile phone, or any other computing device permitted to control the operation of the industrial environment and / or lighting system 100. Accordingly, operator device 150 may include a lighting design application that enables an operator to design the lighting cycles executed by lighting system 100. For example, if lighting system 100 is part of a product production line, the lighting cycle may configure lighting unit 130 to provide various lighting conditions for detecting various features of the product passing in front of image unit 140. Operator device 150 may convert the lighting design into a set of lighting control commands downloaded into processor 120 via the I / O port. Accordingly, processor 120 may configure lighting unit 130 (and / or its various switches) according to the lighting control commands. Operator device 150 may allow an operator to provide desired parameter values for lighting. The parameter values may include, but are not limited to, a desired current to the LEDs, a desired number of LEDs for providing lighting, specific (designated) LEDs for providing lighting, a desired lighting pulse time, a lighting pulse period, a lighting on time, etc.

[0036] Furthermore, the processor 120 can transmit data to the operator device 150 via the I / O port. For example, the memory 134 of the lighting unit 130 may include information regarding the physical and / or logical position (arrangement) of the LEDs 132. Thus, the lighting design application may present an interface showing the layout of the LEDs 132 for improved design control and / or simulation. As another example, the memory 134 may include the model number of the lighting unit 130. Thus, the lighting design application can query a lighting unit database (not shown) to determine (judge) the position (arrangement) of the LEDs. As another example, the processor 120 can obtain the maximum current rating for the LEDs 132 from the memory 134 and provide it to the operator device 150. The processor 120 can obtain one or more eye safety parameter values from the memory 134 to provide eye-safe lighting. Thus, the lighting design application can be configured to simulate control commands before downloading them to the processor 120 to ensure compliance with the maximum current rating.

[0037] Referring now to FIG. 2, an exemplary lighting system 200, which is a variant of the lighting system 100, is illustrated. In particular, the exemplary lighting system 200 includes a power drive device 210 that includes an active discharge circuit 2601. The power drive device 210 also includes a capacitor 215, an LED driver 222, and a processor 220, which may be the storage capacitor 115, the LED driver 122, and the processor 120 of FIG. 1, respectively.

[0038] The active discharge circuit 260 can be configured to discharge the LED voltage (VLED) to the capacitor voltage (VCAP) to ensure safe operation for the eyes of the lighting unit 130. In this regard, the processor 220 can be configured to control the lighting unit 130 to provide continuous lighting pulses with different configurations (forms) of the LED 132. In this case, if the voltage required to drive the LED 132 to provide eye-safe lighting decreases between consecutive lighting pulses, the initially higher lighting voltage may not be discharged sufficiently to fall below the voltage level that provides eye-safe lighting for the next lower lighting pulse. For example, the next lower lighting pulse may activate a smaller number of LEDs 132 and / or operate the LEDs in a different color (e.g., red vs. white lighting) that requires less power and / or may have different eye-safe reference values. The excess voltage at this time can damage the LED 132 when executing the lower lighting pulse or result in lighting that is not safe for the user or operator. By actively discharging the excess voltage, the active discharge circuit 262 ensures the safe operation of the lighting unit 130.

[0039] As shown in the figure, the active discharge circuit 260 includes an input port 262 that enables the processor 220 to activate the active discharge circuit 260. For example, by sending a control signal to the input port 262, the processor 220 closes a switch (not shown) to cause the current supplied by the LED driver 222 to flow through the active discharge circuit 260 instead of the lighting unit 130 (through a lighting port such as the lighting port 119 in FIG. 1). During this time, the capacitor 215 is recharged. Accordingly, the processor 220 can be configured to analyze the lighting control commands stored therein, detect when the voltage required for consecutive lighting pulses decreases, and control the discharge circuit 260 via the input port 262 accordingly.

[0040] Referring to FIG. 3A, an exemplary user interface 300 for an illumination design application executed on an operator device 350 (such as the operator device 150 of FIG. 1) is illustrated. The operator device may be connected to an I / O port of a processor 320 (the processor 120 of FIG. 1, the processor 220 of FIG. 2A, and / or other similarly configured logic circuits). As described above, the illumination design application may be configured to enable an operator to design a set of illumination control commands that represent an illumination cycle executed by an illumination unit (such as the illumination unit 130 of FIGS. 1 and 2).

[0041] The illumination design application may be configured to poll the processor 320 for information to input into the user interface 300. For example, the illumination design application may be configured to obtain an LED layout from the processor 320 and present its visual display 310. In some embodiments, the display of the LED layout 310 may also indicate the position of the LEDs relative to an object. The display representing an individual LED within the LED layout 310 may be selectable to present a corresponding LED configuration panel.

[0042] As shown, the LED configuration panel may include static information 322 that describes the selected LED and programmable information 324. The illumination design application may obtain display information from the processor 320. Accordingly, an operator may modify the programmable information 324 by selecting the interface element 334 and entering a value for each programmable field. It should be understood that when the operator modifies the pulse number field, the user interface 310 may obtain new information corresponding to the new pulse. Accordingly, an operator can design an illumination cycle including any number of pulses via the user interface 300.

[0043] When the operator finishes designing the lighting cycle, the operator can interact with the user element 332 and program the processor 320 with a set of lighting control commands corresponding to the designed lighting cycle. After receiving the set of control commands, the processor 320 can accordingly control one or more switches of the lighting unit and / or can program the LEDs. In some embodiments, before downloading the set of lighting control commands to the processor 320, the lighting design application runs a simulation of the lighting cycle to determine compliance with the operating limits of the LEDs, such as the maximum current. Thus, if the simulated lighting cycle is not executed within the operating limits, the lighting design application can present a warning to the operator. The warning can display specific LEDs that do not conform to the operating limits and can accordingly provide instructions on how to adjust the lighting cycle. Further, the lighting design application determines (judges) whether the input lighting cycle is executed in accordance with eye safety standards. If the simulated lighting cycle is not executed within the operating limits, the lighting design application can display a warning to the operator. FIG. 3B illustrates a lighting design application presenting a warning notification 360 that notifies the operator that the current desired parameter values are not eye-safe and that the user needs to enter new parameter values to provide lighting in accordance with eye safety standards. The lighting design application can determine (judge) whether the desired (desired) input pulse duration, lighting intensity, duty cycle of the pulse train, and / or LED drive current is eye-safe. In embodiments employing multiple color LEDs 132 or color lighting elements, the desired input can be the desired color(s) of the lighting. Thus, the lighting design application can also include an interface for the user to input the desired color or set of colors. For example, the user can input the desired lighting wavelength or lighting wavelength band as the desired input.

[0044] FIG. 4 is a flowchart of a method 400 for controlling illumination in accordance with eye safety standards. The flowchart may be executed by a processor of the illumination system (such as processors 120, 220, 320 of FIGS. 1, 2, 3, and / or another similarly configured logic circuit, etc.). As an example, method 400 of FIG. 4 will be further described with reference to the elements of FIG. 1.

[0045] In block 402, processor 120 is powered. More specifically, processor 120 may be connected to a power source (such as power source 105 of FIG. 1) by closing a switch associated with the power source.

[0046] In block 404, processor 120 accesses memory 134 of illumination unit 130 and obtains device information indicative of the characteristics of illumination unit 130. The device information obtained includes a plurality of parameters of one or more illumination elements of the illumination module. Such illumination elements may include one or more LEDs such as LED 132. The device information may include the category voltage of LED 132, the category current of LED 132, the category temperature of LED 132, the number of LED 132, the LED color of LED 132, the LED binning of LED 132, the grouped arrangement of the LEDs (e.g., the logical arrangement of LED 132 with respect to bank and group numbering), the physical arrangement (e.g., the physical position of LED 132 on illumination unit 130), the relative position of LED 132 to each other, the part number of the LED, the physical position and / or orientation of one or more LEDs on the circuit board, the eye-safe current to be provided to each of LED 132, the eye-safe power to be provided to each of LED 132, the eye-safe illumination output of each of LED 132, the identification number of the circuit board, the type of the circuit board, sensor information (i.e., a temperature sensor or other type of sensor), the model number of illumination unit 130, and / or other information regarding illumination unit 130 and / or LED 132.

[0047] The device information also includes the maximum constant of at least one lighting element (e.g., an LED). The maximum constant indicates the relationship between at least two parameters of the lighting element. Further, the maximum constant indicates the safe operation for the eyes of the lighting unit 130, or the radiation risk group. For example, the eye safety standards adopted by the system 100 may comply with the standards and parameter values specified in the international standard IEC62471:2006 (Ed.1), EN62471:2008. Other eye safety standards may also be used, and eye safety standards updated over time may also be used. The memory 134 may store the values and parameter limitations (conditions) in accordance with the eye safety standards, and the maximum constant indicates one or more parameter limitations.

[0048] The maximum constant may indicate the proportional relationship between the LED drive current and the lighting pulse duration of the LED. For example, an equation for determining the maximum constant may be derived. For example, K = I * t / T (Equation 1) Here, K is the maximum constant for eye safety, I is the LED drive current, t is the duration of the lighting pulse, and T is the reciprocal of the frame rate of a camera such as the image sensor 142. K is a constant, and the frame rate of the system may also be a constant or a set value. On the other hand, the pulse duration and the drive current can be changed according to the desired illumination. Although the drive current and the pulse duration are used in this example, the maximum constant can indicate the relationship between other operating parameters for providing illumination, such as the relationship between the electrical drive current, the illumination output power, the luminous intensity (candela), the luminous flux (lumen), or the total integrated illumination time that the LED can provide illumination, among other lighting or device parameters.

[0049] In block 406, the method includes receiving from the user a desired parameter value of one of the plurality of parameters. Using this example, the user may input a value for the desired lighting pulse duration.

[0050] In block 408, the processor 120 determines a test constant based on the desired parameter value. The test constant is a value for K, and here Ktest is denoted as, and can be used to determine whether the desired parameter value to be input is within the eye safety standard. For example, to supply power to an LED, a current of 2 mA may be required, the frame rate of the sensor may be 60 frames per second, T = 1 / 60 may result, and the user may input a desired parameter value of 2 ms as the pulse duration. This results in a test constant value K test = 0.066.

[0051] In block 410, the processor 120 compares the test constant with the maximum constant to determine whether the desired parameter value is an acceptable value according to the eye safety standard. For example, the maximum constant K for a given lighting unit or a specific lighting device (such as a green LED, etc.) may be a value of 0.1. In this example, the user inputs 2 ms as the desired value of the pulse duration, and as a result, the test constant becomes 0.066, which is smaller than the maximum constant of 0.1. Therefore, the processor 120 compares the test constant with the maximum constant and determines that the desired input parameter value of 2 ms pulse duration is within the eye safety standard and is an acceptable value. If the user changes the desired input value to a pulse duration of 4 ms, the test constant will 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 an acceptable value because it is not safe for the eyes.

[0052] Although it is described here as a step of comparing a maximum constant with a test constant, the processor 120 may further determine an allowable value of a desired input value and compare the desired input value with the determined allowable value of the parameter. For example, the processor 120 may determine from the maximum constant that the maximum current provided to the LED is 2 mA, the user may input a desired parameter value of 2.5 mA, and the processor 120 may compare these two values and determine a safe operation for the eyes during the lighting cycle. As another example, the desired parameter value may be a desired illuminance value (lighting value). At this time, the processor 120 may determine the test constant as the test lighting time, and the plurality of parameters of the lighting element include the total lighting time indicating the amount of time that the lighting element can provide lighting over a given time. Next, the processor 120 determines the test lighting time from the desired illuminance value (lighting value) and the maximum constant. The processor 120 compares the test lighting time with the total lighting time, and determines that the desired illuminance value is an acceptable illuminance value when the test lighting time is less than or equal to the total lighting time, and determines that the desired illuminance value is not an acceptable illuminance value when the test lighting time is greater than the total lighting time. Further, the desired parameter value may be a desired lighting time, and the described method may be performed by determining the test constant as the test lighting amount (time) and comparing the test lighting amount with the maximum allowable lighting amount (time).

[0053] When the processor 120 determines that the desired parameter value is not within the eye safety standard, it may provide a notification to the user or operator. For example, the processor 120 may provide a notification indicating that the current set of parameter values is not safe for the eyes via the lighting design application 300. In block 414, the method includes the step of requesting a new desired parameter value. For example, the processor 120 may provide a notification that a shorter pulse duration is required to operate within the eye safety standard. The user may input another value via the operator device 150, and the method 400 may recalculate the new test constant and determine whether the new desired parameter value is within the eye safety standard.

[0054] In some embodiments, the user (themselves) may decide not to change the desired parameter to an eye-safe value. In such cases, the processor 120 will either shorten the pulse length (e.g., in the case of a global shutter sensor) or reduce the current supplied to the lighting element such as the LED 132 (e.g., in the case of a rolling shutter sensor). The processor 120 may provide the parameter value changed during the execution of the lighting cycle, or may change the value and notify the operator via the operator device 150.

[0055] Alternatively, when the processor 120 determines that the desired parameter is within the eye-safe criteria, at block 412, it configures the LED driver (e.g., the LED drivers 122, 222 of FIGS. 1 and 2) to supply drive current according to the determined eye-safe pulse duration. For this purpose, the processor 120 may send a control signal to the input port of the LED driver, may control the LED driver, and may use the desired parameter value as the current output to the LED.

[0056] The processor 120 may further perform direction control of the LED bank so as to control the LED bank according to the determined eye-safe parameters. The processor 120 may configure the LEDs according to the determined eye-safe lighting cycle. In this regard, the processor may output a set of control commands to one or more GPIO ports to control switches associated with the LED bank and / or groups of LEDs within the LED bank. For example, the processor may send a control signal via a GPIO port implementing a multiplexing technique for signaling the control state of the (multiple) switches of the LED bank and / or LED groups. Further, the lighting unit 130 may include color-programmable LEDs, and the processor may be configured to also set the LED color of the LEDs. After setting the switch and LED color of the lighting unit, the processor may close the switch for connecting the lighting unit to the LED driver. Further, the color of the LEDs may vary the eye-safe drive current, lighting pulse duration, pulse train period, or other value, of a given LED. Accordingly, the method 400 of FIG. 4 may be executed each time the user changes the desired LED color, and it may be determined whether the parameters of the lighting cycle are eye-safe for a given LED color.

[0057] The foregoing description refers to the block diagrams of the accompanying drawings. Alternative implementations of the embodiments represented by the block diagrams include one or more additional or alternative elements, processes, and / or devices. Additionally or alternatively, one or more of the exemplary blocks in the figures may be combined, divided, rearranged, or omitted. The components represented by the blocks in the figures may be implemented by hardware, software, firmware, and / or any combination of hardware, software, and / or firmware. 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 explicitly defined as a physical device that includes at least one hardware component configured to control one or more machines and / or execute the operations of one or more machines (e.g., via operations according to a given configuration and / or via execution of stored machine-readable instructions). 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-chip (SoC) devices. Some exemplary logic circuits, such as ASICs or FPGAs, are hardware specially configured to execute operations (e.g., one or more operations described herein and represented by the flowcharts of the present disclosure, if present). Some exemplary logic circuits are hardware that executes machine-readable instructions to execute operations (e.g., one or more operations described herein and represented by the flowcharts of the present disclosure, if present).Some exemplary logic circuits include a combination of specially configured hardware and hardware that executes machine-readable instructions. The foregoing description refers to the various operations described herein and the flowcharts that may be attached hereto to explain those operation flows. Such flowcharts each represent an exemplary method disclosed herein. In some examples, the method represented by the flowchart implements an apparatus represented by the block diagram. Alternative implementations of the exemplary methods disclosed herein may include additional or alternative operations. Further, the operations of alternative implementations of the methods disclosed herein may be combined, divided, 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., a tangible machine-readable medium) for execution by one or more logic circuits (e.g., a processor). In some examples, the operations described herein are implemented by one or more configurations of one or more specially designed logic circuits (e.g., an ASIC). In some examples, the operations described herein are implemented by a combination of one or more specially designed logic circuits and machine-readable instructions stored on a medium (e.g., a tangible machine-readable medium) for execution by one or more logic circuits.

[0058] As used herein, each of the terms "tangible machine-readable medium", "non-transitory machine-readable medium", and "machine-readable storage device" is explicitly defined as a storage medium (e.g., a disk of a hard disk drive, a digital versatile disk (DVD), a compact disk (CD), a flash memory, a read-only memory (ROM), a random access memory (RAM), etc.) in which machine-readable instructions (e.g., program code in the form of software and / or firmware) are stored for any suitable period of time (e.g., permanently, for a long period (e.g., while a program related to the machine-readable instructions is being executed), and / or for a short period (e.g., while the machine-readable instructions are cached and / or during a buffering process)). Further, as used herein, each of the terms "tangible machine-readable medium", "non-transitory machine-readable medium", and "machine-readable storage device" is explicitly defined to exclude propagation signals (in the form thereof). That is, when used in the claims, none of the terms "tangible machine-readable medium", "non-transitory machine-readable medium", and "machine-readable storage device" can be read as being implemented by a propagated signal.

[0059] The foregoing specification describes specific embodiments. However, one of ordinary skill in the art will understand that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims. Accordingly, the specification and drawings are to be understood in an illustrative rather than a limiting sense, and it is intended that all such modifications be included within the scope of the present teachings. Further, the described embodiments / examples / implementations should not be construed as mutually exclusive, but rather, should be understood to be potentially combinable in some way if such a combination is permitted. In other words, any feature disclosed in any of the foregoing embodiments / examples / implementations may be included in any of the other foregoing embodiments / examples / implementations.

[0060] Benefits, advantages, problem solutions, and any element that can give rise to or make more prominent any benefit, advantage, or solution should not be construed as an important, necessary, or essential function or element in any or all of the claims of the claims of the patent application. The claimed invention is defined only by the appended claims, including amendments made during the pendency of this application and all equivalents of all issued claims.

[0061] Furthermore, in this document, relative terms such as first and second, upper and lower, etc. may only be used to distinguish one entity or operation from another, and may not necessarily require or imply an actual such relationship or order between such entities or operations. The terms "comprises", "comprising", "has", "having", "include", "including", "contains", "containing", or any other variations thereof are intended to cover non-exclusive inclusion. A process, method, article, or apparatus that comprises, has, includes, or contains a listing of elements does not include only those elements, but may also include other elements not expressly listed, or other elements inherent to such process, method, article, or apparatus. Elements following "comprises...a", "has...", "includes...a", or "contains...a" do not, in the absence of further limitations, preclude the presence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, or contains such elements. The terms "a" and "an" are defined as one or more unless expressly stated otherwise. The terms "substantially", "essentially", "approximately", "about", or any other variations thereof are defined as being near in state as would be understood by one of ordinary skill in the art, and in one non-limiting embodiment, the term is defined as within 10%, in another embodiment within 5%, in another embodiment within 1%, and in another embodiment within 0.5%. The term "coupled" as used herein is defined as being connected, but may not necessarily be direct and may not necessarily be mechanical. A device or structure "configured" in a certain manner is at least configured in that manner, but may also be configured in ways not recited.

[0062] The summary of the disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is presented with the understanding that it is not used to interpret or limit the scope or meaning of the claims of the patent claims. Also, in the foregoing detailed description, for the purpose of smoothing the disclosure, it can be recognized that various features are grouped together in various embodiments. This method of disclosure should not be construed as reflecting an intention that the claimed embodiments require more features than those expressly recited in each claim. Rather, as reflected in the following claims, the subject matter of the present invention exists less than all the features of a single disclosed embodiment. The following claims are hereby incorporated into the detailed description, and each claim stands on its own as a separately claimed subject matter.

Claims

1. A method for controlling lighting, comprising: obtaining, by a processor, device information indicating characteristics of a lighting module from a memory of the lighting module ; wherein 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; the maximum constant indicates a relationship between at least two parameters of the lighting element; the method further comprises: receiving, from a user, a desired parameter value for one of the plurality of parameters; determining, by the processor, a test constant from the desired parameter value; determining, by the processor, from the test constant and the maximum constant whether the desired parameter value is an acceptable parameter value; controlling, by the processor, a power supply to provide current to the lighting module according to the desired parameter value; A method characterized by comprising the above steps.

2. The maximum constant indicates a proportional relationship between the current of the lighting element and the output illuminance provided by the lighting element; the test constant indicates either (i) a desired current of the lighting element or (ii) an output illuminance provided by the lighting element. The method according to claim 1, characterized by the above.

3. The step of determining whether the desired parameter value is an acceptable parameter value includes: comparing, by the processor, the test constant and the maximum constant; determining, by the processor, that the desired parameter value is an acceptable parameter value when the test constant is less than or equal to the maximum constant, or determining that the desired parameter value is not an acceptable parameter value when the test constant is greater than the maximum constant. The method according to claim 1, characterized by including the above steps.

4. The desired parameter value is a desired illuminance value; the test constant is a test lighting time; the plurality of parameters of the lighting element include a total lighting time indicating an amount of time for which the lighting element can provide lighting over a given time; the method further comprises: determining, by the processor, a test lighting time from the desired illuminance value and the maximum constant; comparing, by the processor, the test lighting time and the total lighting time; The step of determining by the processor that when the test illumination time is less than or equal to the total illumination time, the desired illuminance value is an acceptable illuminance value, or determining that when the test illumination time is greater than the total illumination time, the desired illuminance value is not an acceptable illuminance value; The method according to claim 1, characterized by comprising the above.

5. The desired parameter value is the desired illumination time, The test constant is the test illuminance value, The plurality of parameters of the lighting element include the maximum illuminance value indicating the amount of light that the lighting element can provide, The method further comprises The step of determining a test illuminance value from the desired illumination time and the maximum constant by the processor; The step of comparing the test illuminance value and the maximum illuminance value by the processor; The step of determining by the processor that when the test illuminance value is less than or equal to the maximum illuminance value, the desired illumination time is an acceptable illumination time, or determining that when the test illuminance value is greater than the maximum illuminance value, the desired illumination time is not an acceptable illumination time; The method according to claim 1, characterized by comprising the above.

6. The lighting module includes one or more light-emitting diodes (LEDs) The method according to claim 1, characterized by comprising the above.

7. The device information includes at least one of identification information of the circuit board, one or more light-emitting diode (LED) characteristics, the type of the circuit board, identification information of the sensor type of the lighting module, and identification information of the lighting module. The method according to claim 1, characterized by comprising the above.

8. The one or more LED characteristics include the color of the LED, the physical group of the LEDs, the relative positions of the LEDs, the position of the LEDs on the circuit board, the part number of the LEDs, the maximum current of the LEDs, the number of the LEDs, the physical position of the LEDs on the lighting module, and the physical orientation of the LEDs on the lighting module. The method according to claim 7, characterized by comprising the above.

9. The maximum constant further indicates the classification of the radiation risk group The method according to claim 1, characterized by comprising the above.

10. The step of determining, by the processor, the maximum value of another parameter from the desired parameter value and the maximum constant The method according to claim 1, further characterized by comprising the above.

11. (i) one or more lighting elements, and (ii) a memory for storing device information A lighting port adapted to receive a lighting module having At least one processor operably connected to the lighting port, A lighting system comprising: The device information indicates characteristics of the lighting module and includes (i) a plurality of parameters of the lighting elements of the lighting module and (ii) a maximum constant for the lighting elements. The maximum constant indicates a relationship between at least two parameters of the lighting elements. The processor Obtains the device information from the memory of the lighting module, Receives a desired parameter value for one of the plurality of parameters at a user interface, Determines a test constant from the desired parameter value, Determines from the test constant and the maximum constant that the desired parameter value is an acceptable parameter value, Controls a power supply to provide current to the lighting module according to the desired parameter value Is configured to A lighting system characterized by that.

12. The lighting module is selectively removable from the lighting system The lighting system according to claim 11, characterized by that.

13. The maximum constant indicates a proportional relationship between the current of the lighting element and the output illuminance provided by the lighting element. The test constant indicates either (i) a desired current of the lighting element or (ii) an output illuminance provided by the lighting element. The lighting system according to claim 11, characterized by that.

14. To determine that the desired parameter value is an acceptable parameter value, the processor further Compares the test constant with the maximum constant, Determines that the desired parameter value is an acceptable parameter value when the test constant is less than or equal to the maximum constant, or determines that the desired parameter value is not an acceptable parameter value when the test constant is greater than the maximum constant. The lighting system according to claim 11, characterized by being configured as such.

15. The desired parameter value is a desired illuminance value, The test constant is a test lighting time, The plurality of parameters of the lighting element includes a total lighting time indicating an amount of time that the lighting element can provide lighting over a given time. To determine that the desired parameter value is an acceptable parameter value, the processor further determines a test illumination time from the desired illumination value and the maximum constant, compares the test illumination time with the total illumination time, and determines that the desired illumination value is an acceptable illumination value when the test illumination time is less than or equal to the total illumination time, or determines that the desired illumination value is not an acceptable illumination value when the test illumination time is greater than the total illumination time The lighting system according to claim 11, characterized in that it is configured as described above.

16. The desired parameter value is a desired illumination time, The test constant is a test illumination value, The plurality of parameters of the lighting element include a maximum illumination value indicating the amount of illumination that the lighting element can provide, To determine that the desired parameter value is an acceptable parameter value, the processor further determines a test illumination value from the desired illumination time and the maximum constant, compares the test illumination value with the maximum illumination value, and determines that the desired illumination time is an acceptable illumination time when the test illumination value is less than or equal to the maximum illumination value, or determines that the desired illumination time is not an acceptable illumination time when the test illumination value is greater than the maximum illumination value The lighting system according to claim 11, characterized in that it is configured as described above.

17. The lighting module includes one or more light emitting diodes (LEDs) The lighting system according to claim 11, characterized in that it is as described above.

18. The device information includes at least one of identification information of a circuit board, one or more light emitting diode (LED) characteristics, the type of the circuit board, identification information of a sensor type of the lighting module, and identification information of the lighting module The lighting system according to claim 11, characterized in that it is as described above.

19. The one or more LED characteristics include the color of the LED, the physical group of the LEDs, the relative position between the LEDs, the position of the LEDs on the circuit board, the part number of the LEDs, the maximum current of the LEDs, the number of the LEDs, the physical position of the LEDs on the lighting module, and the physical orientation of the LEDs on the lighting module The lighting system according to claim 18, characterized in that it is as described above.

20. The maximum constant further indicates a classification of a radiation risk group The lighting system according to claim 11, characterized in that it is as described above.

21. The processor is further configured to determine a maximum value of another parameter from the desired parameter value and the maximum constant. The lighting system according to claim 11, characterized in that.

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