Lighting device and control method

Abstract

A lighting device (100) is provided with: a light source (110) having a plurality of light-emitting elements (111) arranged in an array; a projection lens (120) that projects light emitted from the light source (110); an acquisition unit (130) that acquires input data; a control unit (140) that individually controls the current supplied to each of the plurality of light-emitting elements (111); and a detection unit (150) that detects the temperature of the light source (110). The control unit (140) determines whether or not the temperature of the light source (110) satisfies a predetermined condition, and if it is determined that the temperature of the light source (110) satisfies the predetermined condition, selects a current adjustment algorithm for adjusting the amount of current supplied to each of the plurality of light-emitting elements (111) on the basis of the characteristics of the input data acquired by the acquisition unit (130). On the basis of the selected current adjustment algorithm, the amount of current supplied to each of the plurality of light-emitting elements (111) is adjusted.

Description

TECHNICAL FIELD

[0001] The present application relates to an illumination device and a control method of an illumination device. BACKGROUND

[0002] There is known an apparatus that is provided with a light source having a plurality of LEDs (Light Emitting Diodes) arranged in an array, and is capable of causing the plurality of LEDs to emit light in a prescribed light emission pattern (for example, refer to Patent Literature 1).

[0003] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature 1: Japanese Patent Application Laid-Open No. 2020-95963 SUMMARY

[0004] PROBLEMS TO BE SOLVED BY THE INVENTION In a case where the plurality of LEDs of the light source are arranged in an array, heat load is likely to be applied to the light source, and the thermal reliability of the apparatus is likely to decrease. In addition, in a case where a light emission pattern is projected to a projection surface using a light source having a plurality of LEDs arranged in an array, the appearance of the light emission pattern is also important.

[0005] Therefore, an object of the present application is to provide an illumination device or the like that is capable of suppressing a decrease in the appearance of a light emission pattern and improving thermal reliability.

[0006] MEANS FOR SOLVING THE PROBLEMS An illumination device of one embodiment of the present application includes a light source including a plurality of light emitting elements arranged in an array, a projection lens that projects light emitted from the light source, an acquisition unit that acquires input data related to a light emission pattern of the plurality of light emitting elements, a control unit that individually controls a current supplied to each of the plurality of light emitting elements on the basis of the input data acquired by the acquisition unit, and a detection unit that detects a temperature of the light source, wherein the control unit determines whether the temperature of the light source satisfies a prescribed condition on the basis of the temperature of the light source detected by the detection unit, in a case where it is determined that the temperature of the light source satisfies the prescribed condition, selects a current adjustment algorithm for adjusting an amount of current supplied to each of the plurality of light emitting elements on the basis of a characteristic of the input data acquired by the acquisition unit, and adjusts the amount of current supplied to each of the plurality of light emitting elements on the basis of the selected current adjustment algorithm.

[0007] Further, a control method according to an embodiment of the present application is a control method of a lighting device including a light source including a plurality of light emitting elements arranged in an array, a projection lens that projects light emitted from the light source, and a detection unit that detects a temperature of the light source, the control method including: acquiring input data related to a light emission pattern of the plurality of light emitting elements; individually controlling a current supplied to each of the plurality of light emitting elements based on the acquired input data; determining whether the temperature of the light source satisfies a predetermined condition based on the detected temperature of the light source; in a case where it is determined that the temperature of the light source satisfies the predetermined condition, selecting a current adjustment algorithm for adjusting an amount of the current supplied to each of the plurality of light emitting elements based on a characteristic of the acquired input data; and adjusting the amount of the current supplied to each of the plurality of light emitting elements based on the selected current adjustment algorithm.

[0008] Effects of Invention According to the present application, it is possible to provide a lighting device or the like that can suppress a decrease in appearance of a light emission pattern and can improve heat reliability. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a block diagram showing a configuration of a lighting device according to an embodiment.

[0010] Figure 2 is a schematic perspective view of a lighting device according to an embodiment.

[0011] Figure 3 is a flowchart showing an operation of a lighting device according to an embodiment.

[0012] Figure 4 is a diagram showing an example of a current adjustment algorithm selected in a case where it is determined that a characteristic of input data is character information.

[0013] Figure 5 is a diagram showing an example of a current adjustment algorithm selected in a case where it is determined that a characteristic of input data is character information. Figure 4 is a diagram showing an example of a change in appearance of a light emission pattern when an amount of current is adjusted by the current adjustment algorithm shown in

[0014] Figure 6 is a diagram showing an example of a current adjustment algorithm selected in a case where it is determined that a characteristic of input data is character information.

[0015] Figure 7 is a diagram showing an example of a change in appearance of a light emission pattern when an amount of current is adjusted by the current adjustment algorithm shown in Figure 6

[0016] Figure 8 ​is a drawing indicating an example of a change in appearance of a light emission pattern when the amount of current is adjusted by a mutually different current adjustment algorithm for each region.

[0017] Figure 9 is a drawing indicating another example of a current adjustment algorithm.

[0018] Figure 10 is a drawing indicating still another example of a current adjustment algorithm. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present application will be described in detail using the drawings. Furthermore, each of the embodiments described below indicates one specific example of the present application. Therefore, numerical values, shapes, materials, constituent elements, arrangement and connection modes of the constituent elements, steps, order of steps, and the like shown in the following embodiments are one example, and are not intended to limit the present application. Thus, with respect to constituent elements in the following embodiments that are not recited in the independent claims, the constituent elements are described as arbitrary constituent elements.

[0020] In addition, each drawing is a schematic view, and is not necessarily strictly illustrated. Therefore, for example, the scale and the like are not necessarily consistent in each drawing. In addition, in each drawing, the same reference numeral is assigned to substantially the same structure, and repetitive description is omitted or simplified.

[0021] In addition, in the present specification, terms indicating a relationship between elements, and terms indicating the shape of an element, and a numerical range are not merely expressions of strict meanings, but also expressions including substantially equivalent ranges, for example, a difference of several percent or so.

[0022] EMBODIMENT STRUCTURE First, the structure of the lighting device of the present embodiment will be described using Figure 1 and Figure 2 The structure of the lighting device of the present embodiment will be described.

[0023] Figure 1 is a block diagram indicating the structure of the lighting device 100 of the present embodiment. Figure 2 is a schematic perspective view of the lighting device 100 of the present embodiment.

[0024] As shown in Figure 1 , the lighting device 100 is provided with a light source 110, a projection lens 120, an acquisition section 130, a control section 140, a detection section 150, a communication section 160, and a storage section 170. In addition, as shown in Figure 2 , the lighting device 100 is provided with a frame 180.

[0025] In the present embodiment, the illumination device 100 is, for example, a spot light installed in a wiring fixture (for example, a wiring duct, a ceiling) provided in a ceiling or a wall. The illumination device 100 can also be a down light or a ceiling light, or the like.

[0026] The light source 110 has a plurality of light emitting elements 111 arranged in an array. The light source 110 emits light by being supplied with a current from the control section 140. The plurality of light emitting elements 111 are each controlled by the control section 140 independently of one another to turn on and off and to control the light emission intensity (in other words, the brightness) when turned on. Thus, the plurality of light emitting elements 111 can emit a light emission pattern indicated by input data described later. The light emission pattern can be a static image (in other words, a light emission pattern constant in time) or a dynamic image (in other words, a light emission pattern varying in time).

[0027] The plurality of light emitting elements 111 are each, for example, a μLED. The μLED is a fine LED having a size of 100 μm x 100 μm or less. The μLED emits light by being supplied with a current from the control section 140. The μLED includes, for example, a blue LED and a yellow phosphor arranged on the light emission side of the blue LED. The yellow phosphor is excited by a portion of the blue light emitted by the blue LED to emit yellow light. The μLED emits white light as mixed light of the blue light and the yellow light. Note that the color of the light emitted by the μLED is not particularly limited.

[0028] The plurality of light emitting elements 111 are arranged in a two-dimensional array on a substrate. The substrate is a rigid substrate, but can also be a flexible substrate. The substrate is provided, for example, with pattern wiring for supplying a current from the control section 140 to the plurality of light emitting elements 111 independently of one another.

[0029] The plurality of light emitting elements 111 are arranged, for example, in tens to hundreds in each row and each column within a planar region of a prescribed size on the substrate. The planar region in which the light emitting elements 111 are arranged is, for example, a rectangular region having a side of several mm. Note that the number of light emitting elements 111 and the size of the region in which they are arranged are not particularly limited. By arranging a plurality of light emitting elements 111 in a narrow region, it is possible to achieve miniaturization of the projection lens 120 or an increase in the light intake efficiency.

[0030] The projection lens 120 projects the light emitted by the light source 110 onto a projection surface such as a wall, a floor, a workbench, or a screen. Thus, the light emission pattern of the plurality of light emitting elements 111 is projected onto the projection surface. The projection lens 120 is composed of a plurality of lenses, but can also be composed of a single lens.

[0031] The acquisition unit 130 acquires input data related to the light emission pattern of the plurality of light emitting elements 111. The acquisition unit 130 acquires, for example, the input data transmitted from an external device via the communication unit 160. The acquisition unit 130 can acquire the input data stored in the storage unit 170. The acquisition unit 130 is implemented by, for example, a microcontroller. The microcontroller includes, for example, a nonvolatile memory in which a program is stored, a volatile memory as a temporary storage area for executing the program, an input / output port, a processor that executes the program, and the like. The program can also be stored in the storage unit 170. In addition, the acquisition unit 130 can be a dedicated processing circuit that performs the processing performed by the acquisition unit 130.

[0032] The control unit 140 is a processing circuit that controls the driving of the light source 110. Specifically, the control unit 140 individually controls the current supplied to each of the plurality of light emitting elements 111 on the basis of the input data acquired by the acquisition unit 130. Thereby, the lighting and extinguishing of each of the plurality of light emitting elements 111 and the light emission intensity at the time of lighting are controlled, and the light emission pattern of the plurality of light emitting elements 111 is projected through the projection lens 120. In addition, the control unit 140 adjusts the amount of current supplied to each of the plurality of light emitting elements 111 on the basis of the temperature of the light source 110 detected by the detection unit 150. Details of the control performed by the control unit 140 will be described later. Furthermore, in the present specification, the amount of current represents the amount of current per unit time, unless specifically mentioned.

[0033] The control unit 140 supplies, for example, a current modulated by PWM (Pulse Width Modulation) to each of the plurality of light emitting elements 111. By adjusting the pulse width of the supplied current (that is, adjusting the duty ratio) for each light emitting element 111, the amount of supplied current is adjusted, and the light emission intensity of each light emitting element 111 can be changed, and a dimming function can be achieved. In addition, the dimming method is not particularly limited, and can be an amplitude modulation or a phase modulation method, or the like.

[0034] The control unit 140 is implemented by, for example, an ASIC (Application Specific Integrated Circuit) and a microcontroller. The microcontroller includes, for example, a nonvolatile memory in which a program is stored, a volatile memory as a temporary storage area for executing the program, an input / output port, a processor that executes the program, and the like. The program can also be stored in the storage unit 170. The microcontroller that implements the acquisition unit 130 and the microcontroller that implements the control unit 140 can be the same microcontroller or separate microcontrollers. In addition, the control unit 140 can be a dedicated processing circuit that performs the processing performed by the control unit 140.

[0035] The detection section 150 detects the temperature of the light source 110. The detection section 150 detects the temperature of a portion in the light source 110 in which the plurality of light emitting elements 111 are formed. The detection section 150 can detect the temperature of one portion in the light source 110, or can detect the temperature of a plurality of portions in a plurality of regions into which the light source 110 is divided. The detection section 150 is constituted by one or more temperature sensors. The temperature sensor is, for example, a thermistor, but is not particularly limited.

[0036] The communication section 160 acquires input data related to the light emission pattern of the plurality of light emitting elements 111 by communicating with an external device. The communication section 160 is realized by a communication interface (communication circuit) for communicating with an external device via a network or the like. The communication can be wireless communication, or can be wired communication. The standard of the communication is not particularly limited.

[0037] The storage section 170 stores information and data necessary for the processing performed by the control section 140. The storage section 170 is, for example, a nonvolatile storage device such as an HDD (Hard Disk Drive) or a flash memory.

[0038] The frame 180 accommodates the light source 110, the projection lens 120, the acquisition section 130, the control section 140, the detection section 150, the communication section 160, and the storage section 170. The frame 180 includes, for example, a housing frame that constitutes a housing of the illumination device 100, and a plurality of parts such as a heat sink, but is not particularly limited. The parts that constitute the frame 180 are formed using resin or metal. Furthermore, at least one of the acquisition section 130, the control section 140, the communication section 160, and the storage section 170 can be disposed outside the frame 180.

[0039] In the frame 180, an opening section is provided on the light exit side (the normal direction of the main surface of the substrate) of the light source 110, and the projection lens 120 is disposed so as to block the opening section. In the frame 180, it is not necessary to provide a liquid crystal device or a DMD (Digital Mirror Device) as in a general projector, and thus the illumination device 100 can be miniaturized.

[0040] Operation Next, the operation of the illumination device 100 according to the present embodiment will be described. Figure 3 The operation of the illumination device 100 according to the present embodiment will be described.

[0041] Figure 3 is a flowchart showing the operation of the illumination device 100 according to the present embodiment.

[0042] As Figure 3As shown, firstly, the acquisition unit 130 acquires input data related to the light emission pattern of the plurality of light-emitting elements 111 (step S11). The input data includes pattern information representing the light emission pattern of the plurality of light-emitting elements 111. The pattern information is, for example, information representing the light emission intensity (brightness) of each of the plurality of light-emitting elements 111. The input data may also include label information indicating that the light emission pattern is a character. When the light emission pattern is a dynamic image, the acquisition unit 130 continuously acquires input data, and the pattern information changes over time.

[0043] Next, the control unit 140 supplies current to the light source 110 based on the input data acquired by the acquisition unit 130 (step S12). The control unit 140 controls the current supplied to the plurality of light-emitting elements 111 respectively, so that they become the light emission intensity of the plurality of light-emitting elements 111 as shown in the pattern information. As a result, the light emission pattern of the plurality of light-emitting elements 111, as light emitted by the light source 110, is projected onto the projection surface by the projection lens 120.

[0044] Next, the control unit 140 acquires the temperature of the light source 110 detected by the detection unit 150 (step S13). For example, the control unit 140 stores the information of the temperature of the light source 110 detected by the detection unit 150 and the time in the storage unit 170. The control unit 140 may also continue to acquire the temperature of the light source 110 detected by the detection unit 150 at predetermined intervals of a few seconds to tens of seconds during a predetermined period from the time the light source 110 starts emitting light.

[0045] Next, the control unit 140 determines whether the temperature of the light source 110 meets the specified conditions based on the temperature detected by the detection unit 150 (step S14). The specified conditions are set to the temperature at which the light source 110 may experience thermal degradation.

[0046] In step S14, the control unit 140 determines, for example, whether the temperature of the light source 110 detected by the detection unit 150 in step S13 exceeds a predetermined threshold. If the temperature of the light source 110 detected by the detection unit 150 exceeds the predetermined threshold, the control unit 140 determines that the temperature of the light source 110 meets the predetermined conditions. Therefore, by adjusting the current amount as described later, it is possible to suppress the light source 110 from rising to a temperature that would deteriorate due to heat.

[0047] Furthermore, in step S14, the control unit 140 may predict whether the temperature of the light source 110 exceeds a predetermined threshold based on the temperature of the light source 110 detected by the detection unit 150 in step S13 and the time change of the temperature of the light source 110. In this case, if the control unit 140 predicts that the temperature of the light source 110 exceeds the predetermined threshold, it determines that the temperature of the light source 110 meets the predetermined conditions. In the above prediction, the control unit 140, for example, predicts the maximum temperature under the current conditions for continued light emission based on transitional thermal characteristics such as the current temperature of the light source 110 and the slope of the temperature of the light source 110 relative to time during the predetermined period up to the present. Then, the control unit 140 determines whether the predicted maximum temperature exceeds the predetermined threshold. Therefore, by adjusting the current amount as described later, it is possible to further suppress the light source 110 from rising to a temperature that deteriorates due to heat.

[0048] The threshold used in the above determination is set, for example, based on the heat resistance of the light-emitting element 111.

[0049] If the control unit 140 determines that the temperature of the light source 110 does not meet the specified conditions (no in step S14), it supplies current to the light source 110 without adjusting the current amount (step S15). That is, it supplies current to each of the plurality of light-emitting elements 111 to achieve the light intensity of each of the plurality of light-emitting elements 111 as shown in the pattern information. Therefore, at the time of determination, if the current amount supplied to the light-emitting elements 111 is not adjusted as described later, the current amount supplied to each of the plurality of light-emitting elements 111 does not change, and the current light intensity of each of the plurality of light-emitting elements 111 is maintained. In addition, if the current amount supplied to the light-emitting elements 111 is adjusted as described later at the time of determination, the current amount supplied to each of the plurality of light-emitting elements 111 returns to the current amount before the adjustment.

[0050] Then, after step S15, for example, a few seconds to tens of seconds after step S15, step S13 is performed again.

[0051] On the other hand, when the control unit 140 determines that the temperature of the light source 110 meets the prescribed conditions (yes in step S14), it determines the characteristics of the input data acquired by the acquisition unit 130 (step S16). For example, the control unit 140 determines whether the characteristics of the input data are character information or graphic information. In other words, the characteristics of the input data are the object represented by the luminous pattern.

[0052] Character information, or the characteristic of input data when the luminous pattern functions as an information display, can be categorized as character information. Therefore, character information can include cases where the luminous pattern has symbols for information transmission. Additionally, graphic information, or the characteristic of input data when the luminous pattern functions as illumination or stage lighting, can be categorized as graphic information where the luminous pattern is a graphic that mimics the shape of a character, such as a very thick character.

[0053] The control unit 140 determines the characteristics of the input data, for example, based on the pattern information contained in the input data acquired by the acquisition unit 130. Therefore, even if the input data does not contain information indicating characteristics, the characteristics of the input data can still be determined.

[0054] For example, the control unit 140 determines the characteristics of the input data based on a learned model representing the relationship between the characteristics of the pattern information and the input data. This improves the accuracy of the input data characteristic determination. The learned model, for example, is a model generated by machine learning using training data on which the relationship between the pattern information and the characteristics of the input data is known in advance, and is stored in the storage unit 170. The learned model takes the pattern information as input and outputs the characteristics of the input data. The input to the learned model can also be a feature quantity extracted from the pattern information by the control unit 140. Furthermore, the control unit 140 can determine the characteristics of the input data based on a database relating the characteristics of the pattern information and the input data. This database is stored in the storage unit 170. Additionally, the control unit 140 can also determine the characteristics of the input data based on the proportion of lit light-emitting elements 111 among the multiple light-emitting elements 111 in the pattern information.

[0055] Alternatively, the control unit 140 can also determine the characteristics of the input data based on the tag information contained in the input data. For example, if the tag information indicating that the luminous pattern is a character is contained in the input data, the control unit 140 determines that the characteristic of the input data is character information; if the tag information is not contained in the input data, the control unit 140 determines that the characteristic of the input data is graphic information.

[0056] Next, the control unit 140 selects a current adjustment algorithm for adjusting the amount of current supplied to each of the multiple light-emitting elements 111 based on the characteristics of the determined input data (step S17). Then, the control unit 140 adjusts the amount of current supplied to each of the multiple light-emitting elements 111 based on the selected current adjustment algorithm (step S18).

[0057] Multiple current adjustment algorithms are stored in the storage unit 170. The control unit 140 selects one current adjustment algorithm from the multiple current adjustment algorithms to adjust the current amount based on the characteristics of the determined input data. By applying the selected current adjustment algorithm to adjust the current amount, the current supplied to at least a portion of the multiple light-emitting elements 111 is adjusted, thereby reducing the total current supplied to the multiple light-emitting elements 111 (that is, the current supplied to the light source 110 by the control unit 140). As a result, the current supplied to the light source 110 can be reduced, thus suppressing the temperature rise of the light source 110 and improving the thermal reliability of the light source 110.

[0058] Furthermore, when the detection unit 150 detects the temperature of multiple parts in the light source 110, steps S16 to S18 are performed on the region of the light source 110 corresponding to the part with the temperature that meets the specified conditions. Alternatively, if there is a part with the temperature that meets the specified conditions in any one of the multiple parts, steps S16 to S18 can be performed on the entire light source 110.

[0059] Then, after step S18, step S13 is performed again. Furthermore, if steps S16 to S18 are performed repeatedly, subsequent steps S16 to S18 can be omitted. That is, after step S18, steps S13 and S14 can be performed repeatedly while adjusting the current supplied to the light-emitting element 111 until the temperature of the light source 110 no longer meets the specified conditions. The interval between performing step S13 is, for example, a few seconds to tens of seconds.

[0060] [Determination of input data characteristics and specific examples of current adjustment algorithms] Next, we will explain the characteristics of the input data and provide a specific example of the current adjustment algorithm.

[0061] For example, if the control unit 140 determines that the characteristic of the input data is character information, it selects, as a current adjustment algorithm, the input data. Figure 4 The algorithm shown is such that as the current before adjustment increases, the current after adjustment gradually increases along a downward convex curve. The current before adjustment of each of the multiple light-emitting elements 111 is the amount of current supplied to each light-emitting element 111 in a manner that becomes the light-emitting intensity of each of the multiple light-emitting elements 111 as shown in the pattern information. Figure 4 This diagram illustrates an example of a current adjustment algorithm selected when the characteristic of the input data is determined to be character information. Figure 5 It means through Figure 4 The figure shows an example of how the appearance of the luminescent pattern changes when the current adjustment algorithm adjusts the current amount.

[0062] exist Figure 4 In the diagram, the horizontal axis represents the current supplied to each light-emitting element 111 before adjustment, and the vertical axis represents the current supplied to each light-emitting element 111 after adjustment. Additionally, in... Figure 4 In the diagram, a solid line represents the relationship between the current before and after adjustment when the current is adjusted using a current adjustment algorithm. That is, by applying the current adjustment algorithm, the current supplied to each light-emitting element 111 is adjusted based on the current before adjustment. Figure 4 The correspondence shown by the solid line is set to the adjusted current. Additionally, in Figure 4 In the diagram, dashed lines represent the relationship between the current before and after adjustment when no current adjustment is performed (i.e., the current is the same before and after adjustment). These relationships are used to represent other current adjustment algorithms described later. Figure 6 , Figure 9 as well as Figure 10 The same applies to China.

[0063] exist Figure 4 In the current adjustment algorithm shown, the current remains unchanged before and after the current adjustment for both the light-emitting element 111 with a pre-adjustment current of 0 and the light-emitting element 111 with a pre-adjustment current of the maximum current Imax. That is, the brightness of the light-emitting element 111 emitting light at its maximum brightness and the light-emitting element 111 emitting light at its minimum brightness (in other words, off) remains unchanged. Here, the maximum current Imax can be the maximum current that can be supplied to the light-emitting element 111, or it can be the maximum current among the currents supplied to the multiple light-emitting elements 111 before the current adjustment.

[0064] On the other hand, in the light-emitting element 111 where the current supplied before adjustment is greater than 0 and less than the maximum current Imax, the current after adjustment is less than the current before adjustment. That is, the brightness of the light-emitting element 111, which emits light at an intermediate gray level, decreases. By adjusting the current using such a current adjustment algorithm, the control unit 140 can reduce the amount of current supplied to the light source 110.

[0065] pass Figure 4 The current adjustment algorithm shown adjusts the amount of current supplied to each light-emitting element 111, as follows: Figure 5As shown, before and after adjusting the current, the maximum brightness is maintained in the appearance of the light-emitting pattern of the multiple light-emitting elements 111, but the shape becomes thinner instead of maintained. When the input data is character information, it is important that the characters are recognizable in appearance (to convey the message represented by the characters). Therefore, by maintaining the maximum brightness of the light-emitting pattern, it is possible to suppress the difficulty in recognizing the characters, thereby suppressing the decline in the appearance of the light-emitting pattern. Furthermore, by adjusting the current to reduce the current supplied to the light-emitting elements 111 that emit light at an intermediate gray level, it is possible to suppress the temperature rise of the light source 110.

[0066] exist Figure 4 In the example shown, in the light-emitting element 111, the current supplied before adjustment is the maximum current Imax. The current does not change before and after the current adjustment, but the adjusted current can be smaller than the maximum current Imax within the range that does not affect the appearance of the light-emitting pattern.

[0067] Furthermore, if the control unit 140 determines that the characteristic of the input data is graphic information, it selects, as a current adjustment algorithm, [the appropriate algorithm is needed]. Figure 6 The algorithm shown is such that as the current before adjustment increases, the current after adjustment gradually increases in an upward convex curve. Figure 6 This diagram illustrates an example of a current adjustment algorithm selected when the characteristic of the input data is determined to be graphical information. Figure 7 It means through Figure 6 The figure shows an example of how the appearance of the luminescent pattern changes when the current adjustment algorithm adjusts the current amount.

[0068] exist Figure 6 In the current adjustment algorithm shown, in the light-emitting element 111 where the current supplied before adjustment is 0, the current does not change before and after the current adjustment. That is, the brightness of the light-emitting element 111, which emits light at its minimum brightness (in other words, is off), does not change.

[0069] On the other hand, for light-emitting elements 111 where the initial current is greater than 0, the larger the initial current, the smaller the adjusted current relative to the initial current. Therefore, the lower the brightness of the light-emitting element 111, the more difficult it is to reduce its brightness. Furthermore, for light-emitting elements 111 where the initial current is the maximum current Imax, the adjusted current becomes a current Ia that is smaller than the maximum current Imax. Therefore, the brightness of the light-emitting element 111 emitting light with high grayscale is reduced. By adjusting the current using such a current adjustment algorithm, the amount of current supplied to the light source 110 can be reduced.

[0070] pass Figure 6The current adjustment algorithm shown adjusts the amount of current supplied to the light-emitting element 111 as follows: Figure 7 As shown, before and after the current adjustment, the shape of the light-emitting pattern of the multiple light-emitting elements 111 is maintained, but the maximum brightness is not maintained and it becomes darker. When the input data is graphic information, it is important to correctly display the shape of the graphic in appearance. Therefore, by maintaining the shape of the light-emitting pattern and correctly displaying the shape of the graphic, it is possible to suppress the decline in the appearance of the light-emitting pattern. In addition, by adjusting the current to reduce the amount of current supplied to the light-emitting elements 111 that emit light with high grayscale, it is possible to suppress the temperature rise of the light source 110.

[0071] In a current adjustment algorithm where the adjusted current gradually increases along an upward-convex curve as the original current increases, for example, in each light-emitting element 111, the adjusted current is adjusted to be less than or equal to the original current. This effectively reduces the amount of current supplied to the light source 110. Furthermore, in this current adjustment algorithm, as long as the total current supplied to multiple light-emitting elements 111 can be reduced by adjusting the current, the adjusted current can be greater than the original current in some of the light-emitting elements 111.

[0072] Furthermore, the above description shows an example of the control unit 140 determining whether the characteristic of the input data is character information or graphic information in step S16, but the determination example is not limited to this. Depending on the available light emission pattern, the characteristics of the input data determined by the control unit 140 can be appropriately set to characteristics corresponding to purposes such as transmission, indication, attention reminder, lighting performance, and improved visual recognition.

[0073] Alternatively, for example, in step S16, the control unit 140 may determine, in addition to determining whether the input data's characteristic is either character information or graphic information, whether character information and graphic information are mixed. If the control unit 140 determines that the input data's characteristic is a mixture of character information and graphic information, it divides the planar region in the light source 110 where the light-emitting elements 111 are arranged into regions where light-emitting elements 111 corresponding to character information are present and regions where light-emitting elements 111 corresponding to graphic information are present. Then, the control unit 140 selects a different current adjustment algorithm for each divided region, and adjusts the amount of current supplied to each of the multiple light-emitting elements 111 based on the current adjustment algorithm selected for each divided region.

[0074] Figure 8 This is an example of how the appearance of the luminescent pattern changes when the current is adjusted for each region using different current adjustment algorithms. Figure 8The example shown is a light-emitting pattern where a planar area in the light source 110, in which light-emitting elements 111 are arranged, is divided into area A1, where light-emitting elements 111 corresponding to character information are located, and area A2, where light-emitting elements 111 corresponding to graphic information are located. The control unit 140 selects area A1. Figure 4 The current adjustment algorithm shown is used to adjust the current amount. Select the appropriate option in area A2. Figure 6 The current adjustment algorithm shown is used to adjust the current amount. This maintains the maximum brightness of the luminous pattern in region A1 and the shape of the luminous pattern in region A2. Therefore, by adjusting the current amount corresponding to the characteristics of the input data for each region A1 and A2, the degradation of the appearance of the luminous pattern can be suppressed. Thus, when multiple different characteristics exist mixed in the input data, the control unit 140 divides the light source 110 into regions corresponding to the characteristics and selects a different current adjustment algorithm for each region, thereby more effectively suppressing the degradation of the appearance of the luminous pattern.

[0075] Summarize As described above, the lighting device 100 according to this embodiment includes: a light source 110 having a plurality of light-emitting elements 111 arranged in an array; a projection lens 120 for projecting light emitted by the light source 110; an acquisition unit 130 for acquiring input data related to the light emission pattern of the plurality of light-emitting elements 111; a control unit 140 for individually controlling the current supplied to each of the plurality of light-emitting elements 111 based on the input data acquired by the acquisition unit 130; and a detection unit 150 for detecting the temperature of the light source 110. The control unit 140 determines whether the temperature of the light source 110 meets a predetermined condition based on the temperature detected by the detection unit 150. If the temperature of the light source 110 meets the predetermined condition, the control unit 140 selects a current adjustment algorithm for adjusting the amount of current supplied to each of the plurality of light-emitting elements 111 based on the characteristics of the input data acquired by the acquisition unit 130, and adjusts the amount of current supplied to each of the plurality of light-emitting elements 111 based on the selected current adjustment algorithm.

[0076] Therefore, the amount of current supplied to each of the multiple light-emitting elements 111 can be adjusted according to the temperature of the light source 110, thus suppressing the temperature rise of the light source 110 and reducing its thermal load. Furthermore, by adjusting the amount of current supplied to each of the multiple light-emitting elements 111 using a current adjustment algorithm selected based on the characteristics of the input data, adjustments can be made to the current amount corresponding to the characteristics of the input data. For example, as explained above, a current adjustment algorithm that has minimal impact on the appearance of the illuminated pattern can be selected based on the characteristics of the input data, such as whether it is character information or graphic information. Therefore, according to the lighting device 100, the degradation of the appearance of the illuminated pattern can be suppressed, and thermal reliability can be improved.

[0077] (other) The lighting device and the control method of the lighting device of the present invention have been described above based on the above embodiments, but the present invention is not limited to the above embodiments.

[0078] For example, in the above embodiment, an example of a μLED being used as the light-emitting element 111 is shown, but it is not limited to this. The light-emitting element 111 can also be a general-sized LED or an LED with a size larger than a μLED. In addition, the light-emitting element 111 can be an organic EL element or a laser element.

[0079] Furthermore, for example, the current adjustment algorithm is not limited to those described above. Figure 4 as well as Figure 6 The example shown uses an algorithm that appropriately reduces the total current supplied to the multiple light-emitting elements 111. Figure 9 This is a diagram illustrating another example of a current adjustment algorithm. Figure 10 This is another diagram illustrating a current adjustment algorithm. In Figure 9 In the current adjustment algorithm shown, when the current before adjustment is below a specified value, the current after adjustment increases linearly as the current before adjustment increases, until a specified current Ib, which is smaller than the maximum current Imax, becomes constant. That is, the current supplied to each light-emitting element 111 reaches its limit at the specified current Ib. Furthermore, in Figure 10 In the current adjustment algorithm shown, the adjusted current increases linearly with an increase in the initial current, at a smaller slope than in the case where the current is not adjusted. That is, the current supplied to each light-emitting element 111 decreases by a predetermined percentage.

[0080] Furthermore, in the above embodiments, the processing performed by the specific processing unit may also be executed by other processing units. Additionally, the order of multiple processes may be changed, or multiple processes may be executed in parallel.

[0081] For example, the processing described in the above embodiments can be implemented centrally using a single processing circuit or device, or it can be implemented decentralizedly using multiple processing circuits or devices. Furthermore, the processor executing the above program can be a single unit or multiple units. That is, it can be centrally processed or decentralized.

[0082] Furthermore, in the above embodiments, all or part of the components such as the control unit can be constructed by dedicated hardware, or they can be implemented by executing software programs suitable for each component. Each component can also be implemented by a program execution unit such as a CPU (Central Processing Unit) or processor reading and executing software programs recorded on recording media such as HDD (Hard Disk Drive) or semiconductor memory.

[0083] In addition, components such as the control unit can also be composed of one or more electronic circuits. These one or more electronic circuits can be general-purpose circuits or special-purpose circuits.

[0084] One or more electronic circuits may include, for example, semiconductor devices, integrated circuits (ICs) or light-integrated semiconductor devices (LSIs). An IC or LSI can be integrated onto a single chip or multiple chips. Here, it is referred to as an IC or LSI, but the terminology varies depending on the degree of integration; it may also be called a system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, FPGAs programmed after the LSI is manufactured can also be used for the same purpose.

[0085] Furthermore, the present invention, in its entirety or in specific forms, can also be implemented by a system, apparatus, method, integrated circuit, or computer program. Alternatively, it can be implemented by a computer-readable non-transitory recording medium such as an optical disc, HDD, or semiconductor memory storing the computer program. Additionally, it can be implemented by any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

[0086] Furthermore, this invention also includes various modifications that can be conceived by those skilled in the art to the various embodiments, and the implementation of the embodiments by arbitrarily combining the constituent elements and functions of each embodiment without departing from the spirit of the invention.

[0087] The following examples illustrate lighting devices and control methods of the present invention based on the embodiments described above. The lighting devices and control methods according to the present invention are not limited to the following examples.

[0088] The lighting device according to the first aspect of the present invention includes: a light source having a plurality of light-emitting elements arranged in an array; a projection lens for projecting light emitted by the light source; an acquisition unit for acquiring input data related to the light emission pattern of the plurality of light-emitting elements; a control unit for individually controlling the current supplied to each of the plurality of light-emitting elements based on the input data acquired by the acquisition unit; and a detection unit for detecting the temperature of the light source, wherein the control unit determines whether the temperature of the light source meets a predetermined condition based on the temperature of the light source detected by the detection unit, and if it is determined that the temperature of the light source meets the predetermined condition, the control unit selects a current adjustment algorithm for adjusting the amount of current supplied to each of the plurality of light-emitting elements based on the characteristics of the input data acquired by the acquisition unit, and adjusts the amount of current supplied to each of the plurality of light-emitting elements based on the selected current adjustment algorithm.

[0089] The lighting device according to the second aspect of the present invention is a lighting device according to the first aspect. In the selection of the current adjustment algorithm, if the control unit determines that the characteristic of the input data obtained by the acquisition unit is character information, it selects an algorithm in which the adjusted current gradually increases with the increase of the current before adjustment in a downward convex curve as the current adjustment algorithm.

[0090] The lighting device according to the third aspect of the present invention is a lighting device according to the first or second aspect. In the selection of the current adjustment algorithm, if the control unit determines that the characteristic of the input data obtained by the acquisition unit is graphic information, it selects an algorithm in which the adjusted current gradually increases with the increase of the current before adjustment as an upward convex curve as the current adjustment algorithm.

[0091] The lighting device according to the fourth aspect of the present invention is a lighting device according to any one of the first to third aspects. In the selection of the current adjustment algorithm, the control unit determines the characteristics of the input data based on the pattern information representing the light emission pattern contained in the input data obtained by the acquisition unit, and selects the current adjustment algorithm based on the determined characteristics of the input data.

[0092] The lighting device according to the fifth aspect of the present invention is a lighting device according to any one of the first to fourth aspects. In the selection of the current adjustment algorithm, the control unit determines the characteristics of the input data acquired by the acquisition unit based on a learned model, and selects the current adjustment algorithm based on the determined characteristics of the input data. The learned model represents the relationship between the pattern information representing the light emission pattern contained in the input data and the characteristics of the input data.

[0093] The lighting device according to the sixth aspect of the present invention is a lighting device according to any one of the first to fifth aspects. In determining whether the temperature of the light source meets the prescribed conditions, the control unit determines that the temperature of the light source meets the prescribed conditions if the temperature of the light source detected by the detection unit exceeds a prescribed threshold.

[0094] The lighting device according to the seventh aspect of the present invention is a lighting device according to any one of the first to fifth aspects. In determining whether the temperature of the light source meets the predetermined conditions, the control unit predicts whether the temperature of the light source exceeds a predetermined threshold based on the temperature of the light source detected by the detection unit and the time change of the temperature of the light source. If it is predicted that the temperature of the light source exceeds the predetermined threshold, it determines that the temperature of the light source meets the predetermined conditions.

[0095] The lighting device according to the eighth aspect of the present invention is a lighting device according to any one of the first to seventh aspects. In the selection of the current adjustment algorithm, if it is determined that the characteristic of the input data obtained by the acquisition unit is that character information and graphic information are mixed, the control unit divides the light source into a region where the light-emitting element corresponding to the character information exists and a region where the light-emitting element corresponding to the graphic information exists, and selects different current adjustment algorithms for each of the divided regions.

[0096] The ninth aspect of the present invention relates to a control method for a lighting device, the lighting device comprising: a light source having a plurality of light-emitting elements arranged in an array; a projection lens for projecting light emitted by the light source; and a detection unit for detecting the temperature of the light source. The control method includes the following steps: acquiring input data relating to the light emission pattern of the plurality of light-emitting elements; individually controlling the current supplied to each of the plurality of light-emitting elements based on the acquired input data; determining whether the temperature of the light source meets a predetermined condition based on the detected temperature of the light source; if it is determined that the temperature of the light source meets the predetermined condition, selecting a current adjustment algorithm for adjusting the amount of current supplied to each of the plurality of light-emitting elements based on the characteristics of the acquired input data; and adjusting the amount of current supplied to each of the plurality of light-emitting elements based on the selected current adjustment algorithm.

[0097] Explanation of reference numerals in the attached figures 100 lighting fixtures 110 Light Source 111 Light-emitting element 120 projection lens 130 Acquired Department 140 Control Department 150 Testing Department

Claims

1. A lighting device comprising: The light source has multiple light-emitting elements arranged in an array; The projection lens projects the light emitted by the light source; The acquisition unit acquires input data related to the light emission pattern of the plurality of light-emitting elements; The control unit controls the current supplied to each of the plurality of light-emitting elements individually, based on the input data acquired by the acquisition unit. as well as The detection unit detects the temperature of the light source. The control unit determines whether the temperature of the light source meets the specified conditions based on the temperature detected by the detection unit. If the temperature of the light source meets the specified conditions, the control unit selects a current adjustment algorithm for adjusting the current supplied to each of the plurality of light-emitting elements based on the characteristics of the input data acquired by the acquisition unit. The control unit then adjusts the current supplied to each of the plurality of light-emitting elements according to the selected current adjustment algorithm.

2. The lighting device according to claim 1, In selecting the current adjustment algorithm, if the control unit determines that the characteristic of the input data acquired by the acquisition unit is character information, it selects an algorithm in which the adjusted current gradually increases with the increase of the current before adjustment as a downward convex curve.

3. The lighting device according to claim 1, In selecting the current adjustment algorithm, if the control unit determines that the characteristic of the input data acquired by the acquisition unit is graphical information, it selects an algorithm in which the adjusted current gradually increases with the increase of the current before adjustment as an upward convex curve.

4. The lighting device according to claim 1, In selecting the current adjustment algorithm, the control unit determines the characteristics of the input data based on the pattern information representing the light emission pattern contained in the input data obtained by the acquisition unit, and selects the current adjustment algorithm based on the determined characteristics of the input data.

5. The lighting device according to claim 1, In selecting the current adjustment algorithm, the control unit determines the characteristics of the input data acquired by the acquisition unit based on a learned model, and selects the current adjustment algorithm based on the determined characteristics of the input data, wherein the learned model represents the relationship between the pattern information representing the light emission pattern contained in the input data and the characteristics of the input data.

6. The lighting device according to any one of claims 1 to 5, In determining whether the temperature of the light source meets the specified conditions, if the temperature of the light source detected by the detection unit exceeds a specified threshold, the control unit determines that the temperature of the light source meets the specified conditions.

7. The lighting device according to any one of claims 1 to 5, In determining whether the temperature of the light source meets the specified conditions, the control unit predicts whether the temperature of the light source will exceed a specified threshold based on the temperature of the light source detected by the detection unit and the time change of the temperature of the light source. If it is predicted that the temperature of the light source will exceed the specified threshold, it determines that the temperature of the light source meets the specified conditions.

8. The lighting device according to any one of claims 1 to 5, In selecting the current adjustment algorithm, if the control unit determines that the input data acquired by the acquisition unit has the characteristic of a mixture of character information and graphic information, it divides the light source into regions where light-emitting elements corresponding to the character information exist and regions where light-emitting elements corresponding to the graphic information exist, and selects different current adjustment algorithms for each of the divided regions.

9. A control method for a lighting device, the lighting device comprising: a light source having a plurality of light-emitting elements arranged in an array; A projection lens projects light emitted from the light source; and a detection unit detects the temperature of the light source. The control method includes the following steps: Obtain input data related to the light emission pattern of the plurality of light-emitting elements; The current supplied to each of the plurality of light-emitting elements is individually controlled based on the obtained input data; The temperature of the light source is determined based on the detected temperature of the light source to determine whether the temperature of the light source meets the specified conditions; If it is determined that the temperature of the light source meets the specified conditions, a current adjustment algorithm is selected based on the characteristics of the acquired input data to adjust the amount of current supplied to each of the plurality of light-emitting elements; and The amount of current supplied to each of the plurality of light-emitting elements is adjusted based on the selected current adjustment algorithm.

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