Illumination device and control method

Abstract

To provide an illumination device and the like that can suppress the degradation in appearance of a light emission pattern and can improve thermal reliability.SOLUTION: An illumination device 100 includes: a light source 110 which has a plurality of light-emitting elements 111 arranged in an array; a projection lens 120 which projects light emitted from the light source 110; an acquisition unit 130 which acquires input data; a control unit 140 which individually controls the current supplied to each of the plurality of light-emitting elements 111; and a detection unit 150 which 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, selects a current adjustment algorithm for adjusting a current amount to be 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 when determining that the temperature of the light source 110 satisfies a predetermined condition, and adjusts the current amount to be supplied to each of the plurality of light-emitting elements 111 on the basis of the selected current adjustment algorithm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lighting device and a method for controlling a lighting device. [Background technology]

[0002] 2. Description of the Related Art There is known a device that includes a light source having a plurality of LEDs (Light Emitting Diodes) arranged in an array and can cause the plurality of LEDs to emit light in a predetermined emission pattern (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-95963 A Summary of the Invention [Problem to be solved by the invention]

[0004] When multiple LEDs of a light source are arranged in an array, the light source is likely to be subjected to a thermal load, and the thermal reliability of the device is likely to decrease. In addition, when a light source having multiple LEDs arranged in an array is used to project a light emission pattern onto a projection surface, the appearance of the light emission pattern is also important.

[0005] Therefore, an object of the present invention is to provide a lighting device and the like that can suppress deterioration in the appearance of the light emission pattern and improve thermal reliability. [Means for solving the problem]

[0006] A lighting device according to one aspect of the present invention includes a light source having a plurality of light-emitting elements arranged in an array, a projection lens that projects light emitted by the light source, an acquisition unit that acquires input data regarding the 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 based on 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 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 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 based on 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.

[0007] Moreover, a control method according to one aspect of the present invention is a control method for a lighting device including a light source having a plurality of light-emitting elements arranged in an array, a projection lens that projects light emitted by the light source, and a detection unit that detects a temperature of the light source, the control method comprising the steps of: acquiring input data regarding the 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 or not the temperature of the light source satisfies a predetermined condition based on the detected temperature of the light source; and if it is determined that the temperature of the light source satisfies 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 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. Effect of the Invention

[0008] According to the present invention, it is possible to provide a lighting device or the like that can suppress deterioration in the appearance of a light emission pattern and improve thermal reliability. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a block diagram showing a configuration of a lighting device according to an embodiment. [Diagram 2] FIG. 2 is a schematic perspective view of the lighting device according to the embodiment. [Diagram 3] FIG. 3 is a flowchart showing the operation of the lighting device according to the embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a current adjustment algorithm that is selected when it is determined that the characteristic of the input data is character information. [Diagram 5] FIG. 5 is a diagram showing an example of a change in the appearance of the light emission pattern when the amount of current is adjusted by the current adjustment algorithm shown in FIG. [Figure 6] FIG. 6 is a diagram showing an example of a current adjustment algorithm that is selected when it is determined that the characteristics of the input data are graphic information. [Figure 7] FIG. 7 is a diagram showing an example of a change in the appearance of the light emission pattern when the amount of current is adjusted by the current adjustment algorithm shown in FIG. [Figure 8] FIG. 8 is a diagram showing an example of changes in the appearance of the light emission pattern when the amount of current is adjusted by different current adjustment algorithms for each region. [Figure 9] FIG. 9 is a diagram showing another example of a current adjustment algorithm. [Figure 10] FIG. 10 is a diagram showing yet another example of a current adjustment algorithm. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0011] In addition, each figure is a schematic diagram and is not necessarily illustrated precisely. Therefore, for example, the scales in each figure do not necessarily match. In addition, in each figure, substantially the same configurations are given the same reference numerals, and duplicated explanations are omitted or simplified.

[0012] Furthermore, in this specification, terms indicating relationships between elements, terms indicating the shapes of elements, and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

[0013] (Embodiment) [composition] First, the configuration of the lighting device according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG.

[0014] Fig. 1 is a block diagram showing a configuration of a lighting device 100 according to the present embodiment. Fig. 2 is a schematic perspective view of the lighting device 100 according to the present embodiment.

[0015] 1, the illumination device 100 includes a light source 110, a projection lens 120, an acquisition unit 130, a control unit 140, a detection unit 150, a communication unit 160, and a storage unit 170. In addition, as shown in FIG. 2, the illumination device 100 includes a housing 180.

[0016] In this embodiment, the lighting device 100 is, for example, a spotlight, and is attached to a wiring device (for example, a wiring duct, a ceiling hook) provided on a ceiling or a wall. The lighting device 100 may be a downlight, a ceiling light, or the like.

[0017] The light source 110 has a plurality of light-emitting elements 111 arranged in an array. The light source 110 emits light when a current is supplied by the control unit 140. The control unit 140 controls each of the plurality of light-emitting elements 111 independently of one another in terms of turning on and off and the light-emitting intensity (in other words, brightness) when turned on. This allows the plurality of light-emitting elements 111 to emit light in a light-emitting pattern indicated by input data, which will be described later. The light-emitting pattern may be a still image (i.e., a light-emitting pattern that is constant over time) or a moving image (i.e., a light-emitting pattern that changes over time).

[0018] Each of the multiple light-emitting elements 111 is, for example, a μLED. A μLED is a minute LED with a size of 100 μm×100 μm or less. The μLED emits light by a current supplied from the control unit 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 a mixture of blue light and yellow light. The color of the light emitted by the μLED is not particularly limited.

[0019] The light emitting elements 111 are arranged in a two-dimensional array on a substrate. The substrate is a rigid substrate, but may be a flexible substrate. The substrate is provided with, for example, pattern wiring for supplying a current from the control unit 140 to each of the light emitting elements 111.

[0020] The multiple light emitting elements 111 are arranged, for example, in a planar area of ​​a predetermined size on a substrate, with tens to hundreds of elements arranged in each row and column. The planar area in which the light emitting elements 111 are arranged is, for example, a rectangular area with a side of several mm. The number of the light emitting elements 111 and the size of the area in which they are arranged are not particularly limited. By arranging the multiple light emitting elements 111 in a narrow area, it is possible to reduce the size of the projection lens 120 or improve the light capture efficiency.

[0021] The projection lens 120 projects the light emitted by the light source 110 onto a projection surface such as a wall, a floor, a stage, or a screen. This causes the light emission pattern of the multiple light emitting elements 111 to be projected onto the projection surface. The projection lens 120 is composed of multiple lenses, but may be composed of a single lens.

[0022] 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, input data transmitted from an external device via the communication unit 160. The acquisition unit 130 may acquire the input data stored in the storage unit 170. The acquisition unit 130 is realized, for example, by a microcontroller. The microcontroller includes, for example, a non-volatile memory in which a program is stored, a volatile memory which is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like. The program may be stored in the storage unit 170. The acquisition unit 130 may also be a dedicated processing circuit for performing the processing performed by the acquisition unit 130.

[0023] 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 based on the input data acquired by the acquisition unit 130. This controls the turning on and off of each of the plurality of light-emitting elements 111 and the light emission intensity when turned on, and the light emission pattern of the plurality of light-emitting elements 111 is projected by 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 based on 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. In this specification, the amount of current indicates the amount of current per unit time unless otherwise specified.

[0024] The control unit 140 supplies, for example, a current modulated by PWM (Pulse Width Modulation) to each of the multiple light-emitting elements 111. By adjusting the amount of current supplied by adjusting the pulse width of the current supplied to each light-emitting element 111 (i.e., by adjusting the duty ratio), it is possible to change the emission intensity of each light-emitting element 111 and realize a dimming function. Note that the dimming method is not particularly limited, and may be an amplitude modulation method, a phase modulation method, or the like.

[0025] The control unit 140 is realized by, for example, an ASIC (Application Specific Integrated Circuit) and a microcontroller. The microcontroller includes, for example, a non-volatile memory in which a program is stored, a volatile memory which is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like. The program may be stored in the storage unit 170. The microcontroller for realizing the acquisition unit 130 and the microcontroller for realizing the control unit 140 may be the same or may be separate. Furthermore, the control unit 140 may be a dedicated processing circuit for performing the processing performed by the control unit 140.

[0026] The detection unit 150 detects the temperature of the light source 110. The detection unit 150 detects the temperature of a location in the light source 110 where the multiple light emitting elements 111 are formed. The detection unit 150 may detect the temperature of one location in the light source 110, or may detect the temperature of multiple locations in each of the multiple regions when the light source 110 is divided into multiple regions. The detection unit 150 is configured with one or more temperature sensors. The temperature sensor is, for example, a thermistor, but is not particularly limited.

[0027] The communication unit 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 unit 160 is realized by a communication interface (communication circuit) for communicating with an external device via a network or the like. The communication may be wireless communication or wired communication. There is no particular limitation on the communication standard.

[0028] The storage unit 170 stores information and data necessary for processing performed by the control unit 140. The storage unit 170 is, for example, a non-volatile storage device such as a hard disk drive (HDD) or a flash memory.

[0029] The housing 180 houses the light source 110, the projection lens 120, the acquisition unit 130, the control unit 140, the detection unit 150, the communication unit 160, and the storage unit 170. The housing 180 includes, for example, a shell housing forming the outer shell of the lighting device 100, and a plurality of components such as a heat sink, but is not particularly limited thereto. The components constituting the housing 180 are formed using resin or metal. At least one of the acquisition unit 130, the control unit 140, the communication unit 160, and the storage unit 170 may be disposed outside the housing 180.

[0030] An opening is provided in the housing 180 on the light emission side of the light source 110 (in the normal direction of the main surface of the substrate), and the projection lens 120 is disposed so as to cover the opening. Since there is no need to provide a liquid crystal device or a DMD (Digital Mirror Device) inside the housing 180 as in a general projector, the lighting device 100 can be made compact.

[0031] [Operation] Next, the operation of the lighting device 100 according to the present embodiment will be described with reference to FIG.

[0032] FIG. 3 is a flowchart showing the operation of lighting device 100 according to the present embodiment.

[0033] 3, first, the acquisition unit 130 acquires input data related to the light emission pattern of the multiple light emitting elements 111 (step S11). The input data includes pattern information indicating the light emission pattern of the multiple light emitting elements 111. The pattern information is, for example, information indicating the light emission intensity (brightness) of each of the multiple light emitting elements 111. The input data may further include tag information indicating that the light emission pattern is a character. When the light emission pattern is a moving image, the acquisition unit 130 continuously acquires the input data, and the pattern information changes over time.

[0034] Next, the control unit 140 supplies a 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 each of the plurality of light-emitting elements 111 so that the light emission intensity of each of the plurality of light-emitting elements 111 corresponds to the light emission intensity indicated by the pattern information. As a result, the light emission pattern of the plurality of light-emitting elements 111 is projected onto the projection surface by the projection lens 120 as light emitted by the light source 110.

[0035] 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 temperature of the light source 110 detected by the detection unit 150 in the storage unit 170 in association with time information. The control unit 140 may continue to acquire the temperature of the light source 110 detected by the detection unit 150 at predetermined intervals of about several seconds to several tens of seconds for a predetermined period after the light source 110 starts to emit light.

[0036] Next, the control unit 140 determines whether or not the temperature of the light source 110 satisfies a predetermined condition based on the temperature of the light source 110 detected by the detection unit 150 (step S14). The predetermined condition is set to a temperature condition at which the light source 110 may be thermally deteriorated.

[0037] In step S14, the control unit 140 determines whether or not the temperature of the light source 110 detected by the detection unit 150 in step S13 exceeds a predetermined threshold. At this time, the control unit 140 determines that the temperature of the light source 110 satisfies a predetermined condition when the temperature of the light source 110 detected by the detection unit 150 exceeds the predetermined threshold. This makes it possible to prevent the light source 110 from rising to a temperature at which it is deteriorated by heat.

[0038] 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 change over time in the temperature of the light source 110. In this case, when the control unit 140 predicts that the temperature of the light source 110 will exceed the predetermined threshold, it determines that the temperature of the light source 110 satisfies the predetermined condition. In the above prediction, the control unit 140 predicts the maximum temperature when light emission is continued under the current conditions, for example, based on the current temperature of the light source 110 and transient thermal characteristics such as the gradient of the time change in the temperature of the light source 110 for a predetermined period up to the present. Then, the control unit 140 determines whether the predicted maximum temperature exceeds the predetermined threshold. This can further suppress the light source 110 from rising to a temperature at which it deteriorates due to heat.

[0039] The predetermined threshold value used in the above determination is set based on the heat resistance of the light emitting element 111, for example.

[0040] When the control unit 140 determines that the temperature of the light source 110 does not satisfy the predetermined condition (No in step S14), it supplies a current to the light source 110 without adjusting the amount of current (step S15). That is, a current that provides the light emission intensity of each of the plurality of light-emitting elements 111 indicated by the pattern information is supplied to each of the plurality of light-emitting elements 111. Therefore, when the amount of current to the light-emitting elements 111 is not adjusted as described below, the amount of current supplied to each of the plurality of light-emitting elements 111 does not change, and each of the plurality of light-emitting elements 111 maintains the current light emission intensity. When the amount of current to the light-emitting elements 111 is adjusted as described below, the amount of current supplied to each of the plurality of light-emitting elements 111 returns to the amount of current before adjustment.

[0041] Then, after step S15, for example, several seconds to several tens of seconds after step S15, step S13 is performed again.

[0042] On the other hand, when the control unit 140 determines that the temperature of the light source 110 satisfies the predetermined condition (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 indicated by the light emission pattern.

[0043] Being text information can also be said to be a characteristic of input data when a light-emitting pattern functions as an information display. Therefore, being text information can include cases where a light-emitting pattern has a symbol for transmitting information. Also, being graphic information can also be said to be a characteristic of input data when a light-emitting pattern functions as illumination light or stage lighting. Therefore, being graphic information can include cases where a light-emitting pattern is a graphic shape that resembles a character, such as a single very large and thick character.

[0044] The control unit 140 determines the characteristics of the input data based on, for example, pattern information included in the input data acquired by the acquisition unit 130. This makes it possible to determine the characteristics of the input data even if the input data does not include information indicating the characteristics.

[0045] For example, the control unit 140 determines the characteristics of the input data based on a trained model indicating the relationship between the pattern information and the characteristics of the input data. This can improve the accuracy of determining the characteristics of the input data. The trained model is generated by performing machine learning on the model using teacher data in 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 trained model takes the pattern information as input and outputs the characteristics of the input data. The input of the trained model may be a feature extracted from the pattern information by the control unit 140. The control unit 140 may also determine the characteristics of the input data based on a database in which the pattern information and the characteristics of the input data are associated with each other. The database is stored in the storage unit 170. The control unit 140 may also determine the characteristics of the input data based on the ratio of the light-emitting elements 111 that are turned on among the multiple light-emitting elements 111 in the pattern information.

[0046] Furthermore, the control unit 140 may determine the characteristics of the input data based on tag information included in the input data. For example, when the input data includes tag information indicating that the light emission pattern is a character, the control unit 140 determines that the characteristics of the input data are character information, and when the input data does not include the tag information, the control unit 140 determines that the characteristics of the input data are graphic information.

[0047] Next, 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 determined characteristics of the input data (step S17). Then, the control unit 140 adjusts the amount of current supplied to each of the plurality of light-emitting elements 111 based on the selected current adjustment algorithm (step S18).

[0048] A plurality of current adjustment algorithms are stored in the storage unit 170, and the control unit 140 selects one current adjustment algorithm to be used for adjusting the amount of current from the plurality of current adjustment algorithms based on the determined characteristics of the input data. By applying the selected current adjustment algorithm to the adjustment of the amount of current, the amount of current supplied to at least some of the plurality of light-emitting elements 111 is adjusted so that the total amount of current supplied to the plurality of light-emitting elements 111 (i.e., the amount of current supplied to the light source 110 by the control unit 140) is reduced. This makes it possible to reduce the amount of current supplied to the light source 110, thereby suppressing a temperature rise in the light source 110 and improving the thermal reliability of the light source 110.

[0049] When the detection unit 150 detects the temperatures of multiple locations in the light source 110, for example, the processes from step S16 to step S18 are performed on an area corresponding to a location in the light source 110 whose temperature satisfies a predetermined condition. Also, if there is even one location among the multiple locations whose temperature satisfies a predetermined condition, the processes from step S16 to step S18 may be performed on the entire light source 110.

[0050] Then, after step S18, step S13 is performed again. When the processes from step S16 to step S18 are performed repeatedly, the processes from step S16 to step S18 may be omitted from the second and subsequent times. In other words, after step S18, steps S13 and S14 may be repeated while the amount of current supplied to the light emitting element 111 is adjusted until the temperature of the light source 110 no longer satisfies the predetermined condition. The interval at which step S13 is performed is, for example, about several seconds to several tens of seconds.

[0051] [Specific examples of input data characteristic determination and current adjustment algorithms] Next, a specific example of an algorithm for determining the characteristics of input data and adjusting the current will be described.

[0052] For example, when the control unit 140 determines that the characteristic of the input data is character information, the control unit 140 selects, as the current adjustment algorithm, an algorithm in which the amount of current after adjustment gradually increases in a downwardly convex curve as the amount of current before adjustment increases, as shown in Fig. 4. The amount of current before adjustment for each of the plurality of light-emitting elements 111 is the amount of current supplied to each of the plurality of light-emitting elements 111 so that the light emission intensity of each of the plurality of light-emitting elements 111 is indicated by the pattern information. Fig. 4 is a diagram showing an example of a current adjustment algorithm selected when the characteristic of the input data is determined to be character information. Fig. 5 is a diagram showing an example of a change in the appearance of the light emission pattern when the amount of current is adjusted by the current adjustment algorithm shown in Fig. 4.

[0053] In FIG. 4, the horizontal axis indicates the amount of current supplied to each light-emitting element 111 before adjustment, and the vertical axis indicates the amount of current supplied to each light-emitting element 111 after adjustment. In addition, in FIG. 4, the relationship between the amount of current before adjustment and the amount of current after adjustment when the amount of current is adjusted by a current adjustment algorithm is shown by a solid line. That is, by applying the current adjustment algorithm, the amount of current supplied to each light-emitting element 111 is set to the amount of current after adjustment in accordance with the correspondence shown by the solid line in FIG. 4 according to the amount of current before adjustment. In addition, in FIG. 4, the relationship between the amount of current before adjustment and the amount of current after adjustment when no adjustment of the amount of current is performed (that is, when the amount of current is the same before and after adjustment) is shown by a broken line. The same applies to FIG. 6, FIG. 9, and FIG. 10 showing other current adjustment algorithms described later.

[0054] 4, in the light-emitting element 111 to which the amount of current supplied before adjustment is 0 and the light-emitting element 111 to which the amount of current supplied before adjustment is the maximum current amount Imax, the amount of current does not change before and after the adjustment of the amount of current. That is, the luminance of the light-emitting element 111 emitting light at the maximum luminance and the light-emitting element 111 emitting light at the minimum luminance (in other words, turned off) does not change. Here, the maximum current amount Imax may be the maximum amount of current that can be supplied to the light-emitting element 111, or may be the maximum amount of current among the amounts of current supplied to each of the multiple light-emitting elements 111 before the adjustment of the amount of current.

[0055] On the other hand, for the light emitting element 111 to which the amount of current supplied before adjustment is greater than 0 and smaller than the maximum current amount Imax, the amount of current after adjustment becomes smaller than the amount of current before adjustment. That is, the luminance of the light emitting element 111 emitting light at an intermediate gradation decreases. The control unit 140 can reduce the amount of current supplied to the light source 110 by adjusting the amount of current using such a current adjustment algorithm.

[0056] As a result of adjusting the amount of current supplied to each light-emitting element 111 by the current adjustment algorithm shown in FIG. 4, as shown in FIG. 5, the brightness is maintained in the appearance of the light-emitting pattern of the multiple light-emitting elements 111 before and after the adjustment of the amount of current, but the shape is not maintained and becomes thinner. When the input data has the characteristic of character information, it is important that the characters can be visually recognized (the message indicated by the characters is conveyed). Therefore, by maintaining the brightness of the light-emitting pattern, it is possible to prevent the characters from becoming difficult to recognize, and therefore it is possible to prevent the appearance of the light-emitting pattern from deteriorating. In addition, by adjusting the amount of current to reduce the amount of current supplied to the light-emitting elements 111 that emit light in intermediate gradations, it is possible to prevent the temperature rise of the light source 110.

[0057] In the example shown in FIG. 4, in the light-emitting element 111 in which the amount of current supplied before adjustment is the maximum current amount Imax, the amount of current does not change before and after the current amount adjustment, but the amount of current after adjustment may be smaller than the maximum current amount Imax as long as it does not affect the appearance of the light emission pattern.

[0058] Furthermore, when the control unit 140 determines that the characteristic of the input data is graphic information, for example, it selects an algorithm in which the amount of current after adjustment gradually increases in an upwardly convex curve as the amount of current before adjustment increases, as shown in Fig. 6, as the current adjustment algorithm. Fig. 6 is a diagram showing an example of a current adjustment algorithm selected when it is determined that the characteristic of the input data is graphic information. Fig. 7 is a diagram showing an example of a change in the appearance of the light emission pattern when the amount of current is adjusted by the current adjustment algorithm shown in Fig. 6.

[0059] 6, in the light-emitting element 111 to which the amount of current supplied before adjustment is 0, the amount of current does not change before and after the adjustment of the amount of current. In other words, the luminance of the light-emitting element 111 emitting light at the minimum luminance (in other words, turned off) does not change.

[0060] On the other hand, in the light emitting element 111 in which the amount of current supplied before adjustment is greater than 0, the greater the amount of current before adjustment, the smaller the amount of current after adjustment relative to the amount of current before adjustment. Therefore, the lower the luminance of the light emitting element 111, the less likely the luminance is to decrease. Also, in the light emitting element 111 in which the amount of current supplied before adjustment is the maximum current amount Imax, the amount of current after adjustment becomes the current amount Ia which is smaller than the maximum current amount Imax. Therefore, the luminance of the light emitting element 111 emitting light at a high gradation decreases. By adjusting the amount of current using such a current adjustment algorithm, the amount of current supplied to the light source 110 can be reduced.

[0061] As a result of adjusting the amount of current supplied to the light emitting elements 111 by the current adjustment algorithm shown in FIG. 6, as shown in FIG. 7, the shape of the light emitting pattern of the multiple light emitting elements 111 is maintained before and after the adjustment of the amount of current, but the brightness is not maintained and becomes darker. When the characteristic of the input data is graphic information, it is important that the shape of the graphic is displayed correctly in terms of appearance. Therefore, by maintaining the shape of the light emitting pattern, the shape of the graphic is displayed correctly, and the deterioration of the appearance of the light emitting pattern can be suppressed. In addition, by reducing the amount of current supplied to the light emitting elements 111 that emit light at a high gradation by adjusting the amount of current, the temperature rise of the light source 110 can be suppressed.

[0062] In a current adjustment algorithm in which the amount of current after adjustment gradually increases in an upwardly convex curve as the amount of current before adjustment increases, for example, the amount of current after adjustment is adjusted so that it is equal to or less than the amount of current before adjustment in each light-emitting element 111. This makes it possible to effectively reduce the amount of current supplied to the light source 110. Note that in this current adjustment algorithm, as long as the total amount of current supplied to the multiple light-emitting elements 111 can be reduced by adjusting the amount of current, the amount of current after adjustment may be greater in some of the light-emitting elements 111 than the amount of current before adjustment.

[0063] In the above, in step S16, the control unit 140 determines whether the characteristic of the input data is character information or graphic information, but the determination example is not limited to this. Depending on the light emission pattern that can be used, the characteristic of the input data determined by the control unit 140 can be appropriately set to a characteristic according to the purpose such as communication, instruction, attention, lighting effect, and visibility improvement.

[0064] Also, for example, in step S16, the control unit 140 may determine whether the characteristic of the input data is a mixture of character information and graphic information, in addition to whether the characteristic of the input data is character information or graphic information. When the control unit 140 determines that the characteristic of the input data is a mixture of character information and graphic information, it divides the light source 110 into an area where the light emitting elements 111 corresponding to the character information exist and an area where the light emitting elements 111 corresponding to the graphic information exist. Then, the control unit 140 selects a current adjustment algorithm different from each other for each divided area, 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 area.

[0065] FIG. 8 is a diagram showing an example of a change in the appearance of a light emission pattern when the amount of current is adjusted by a current adjustment algorithm different for each region. The example shown in FIG. 8 is a light emission pattern when the light source 110 is divided into a region A1 where the light emitting element 111 corresponding to character information exists and a region A2 where the light emitting element 111 corresponding to graphic information exists. The control unit 140 adjusts the amount of current by selecting the current adjustment algorithm shown in FIG. 4 in the region A1, and adjusts the amount of current by selecting the current adjustment algorithm shown in FIG. 6 in the region A2. As a result, the brightness of the light emission pattern is maintained in the region A1, and the shape of the light emission pattern is maintained in the region A2. Therefore, the amount of current is adjusted according to the characteristics of the input data for each of the regions A1 and A2, and the deterioration of the appearance of the light emission pattern can be suppressed. In this way, when a plurality of characteristics different from each other are mixed in the input data, the control unit 140 divides the light source 110 into regions corresponding to the characteristics and selects a current adjustment algorithm different from each other for each divided region, thereby more effectively suppressing the deterioration of the appearance of the light emission pattern.

[0066] [summary] As described above, the lighting device 100 according to the present embodiment includes the light source 110 having the plurality of light-emitting elements 111 arranged in an array, the projection lens 120 that projects the light emitted by the light source 110, the acquisition unit 130 that acquires input data related to the light emission pattern of the plurality of light-emitting elements 111, the control unit 140 that individually controls 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 the detection unit 150 that detects the temperature of the light source 110. The control unit 140 determines whether the temperature of the light source 110 satisfies a predetermined condition based on the temperature of the light source 110 detected by the detection unit 150, and when 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 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.

[0067] This allows the amount of current supplied to each of the plurality of light-emitting elements 111 to be adjusted according to the temperature of the light source 110, thereby suppressing the temperature rise of the light source 110 and reducing the thermal load of the light source 110. In addition, the amount of current supplied to each of the plurality of light-emitting elements 111 is adjusted by a current adjustment algorithm selected based on the characteristics of the input data, so that the amount of current can be adjusted according to the characteristics of the input data. For example, as described above, it is possible to select a current adjustment algorithm that has little effect on the appearance of the light emission pattern depending on whether the characteristics of the input data are character information or graphic information. Therefore, according to the lighting device 100, it is possible to suppress deterioration in the appearance of the light emission pattern and improve thermal reliability.

[0068] (others) Although the lighting device and the lighting device control method according to the present invention have been described based on the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment.

[0069] For example, in the above embodiment, the light emitting element 111 is a μLED, but the present invention is not limited to this. The light emitting element 111 may be an LED that is larger than a μLED, such as an LED of a general size. The light emitting element 111 may be an organic EL element or a laser element.

[0070] Also, for example, the current adjustment algorithm is not limited to the examples shown in FIG. 4 and FIG. 6 described above, and an algorithm that reduces the total amount of current supplied to the plurality of light-emitting elements 111 is appropriately used. FIG. 9 is a diagram showing another example of the current adjustment algorithm. FIG. 10 is a diagram showing yet another example of the current adjustment algorithm. In the current adjustment algorithm shown in FIG. 9, when the amount of current before adjustment is equal to or less than a predetermined amount, the amount of current after adjustment increases linearly as the amount of current before adjustment increases, and becomes constant at a predetermined current amount Ib smaller than the maximum current amount Imax. That is, the amount of current supplied to each light-emitting element 111 peaks out at the predetermined current amount Ib. In addition, in the current adjustment algorithm shown in FIG. 10, the amount of current after adjustment increases linearly as the amount of current before adjustment increases, with a smaller slope than when the amount of current is not adjusted. That is, the amount of current supplied to each light-emitting element 111 decreases by a predetermined percentage.

[0071] In the above embodiment, the process executed by a specific processing unit may be executed by another processing unit. The order of multiple processes may be changed, or multiple processes may be executed in parallel.

[0072] For example, the processes described in the above embodiments may be realized by centralized processing using a single processing circuit or device, or may be realized by distributed processing using multiple processing circuits or devices. Also, the processor that executes the above program may be single or multiple. That is, centralized processing or distributed processing may be performed.

[0073] In the above embodiment, all or part of the components such as the control unit may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU (Central Processing Unit) or a processor reading and executing a software program recorded on a recording medium such as a HDD (Hard Disk Drive) or a semiconductor memory.

[0074] Furthermore, components such as the control unit may be configured with one or more electronic circuits. Each of the one or more electronic circuits may be a general-purpose circuit or a dedicated circuit.

[0075] The one or more electronic circuits may include, for example, a semiconductor device, an IC, or an LSI. The IC or LSI may be integrated into one chip or into multiple chips. Here, we refer to it as an IC or an LSI, but depending on the degree of integration, it may be called a system LSI, a VLSI (Very Large Scale Integration), or an ULSI (Ultra Large Scale Integration). Also, an FPGA that is programmed after the LSI is manufactured can be used for the same purpose.

[0076] Furthermore, the general or specific aspects of the present invention may be realized as a system, an apparatus, a method, an integrated circuit, or a computer program. Alternatively, the present invention may be realized as a computer-readable non-transitory recording medium such as an optical disk, a HDD, or a semiconductor memory in which the computer program is stored. Furthermore, the present invention may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0077] In addition, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art may think of, and forms realized by arbitrarily combining the components and functions of each embodiment within the scope that does not deviate from the spirit of the present invention.

[0078] An example of the lighting device and the control method according to the present invention described based on the above embodiment will be described below. The lighting device and the control method according to the present invention are not limited to the following examples.

[0079] A lighting device according to a first aspect of the present invention includes a light source having a plurality of light-emitting elements arranged in an array, a projection lens that projects light emitted by the light source, an acquisition unit that acquires input data regarding the 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 based on 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 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 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 based on 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.

[0080] A lighting device according to a second aspect of the present invention is the lighting device according to the first aspect, wherein, when the control unit determines, in selecting the current adjustment algorithm, that the characteristics of the input data acquired by the acquisition unit are character information, the control unit selects, as the current adjustment algorithm, an algorithm in which the amount of current after adjustment gradually increases in a downwardly convex curve as the amount of current before adjustment increases.

[0081] A lighting device according to a third aspect of the present invention is the lighting device according to the first or second aspect, wherein, when the control unit determines, in selecting the current adjustment algorithm, that the characteristics of the input data acquired by the acquisition unit are graphical information, the control unit selects, as the current adjustment algorithm, an algorithm in which the amount of current after adjustment gradually increases in an upwardly convex curve as the amount of current before adjustment increases.

[0082] A lighting device according to a fourth aspect of the present invention is the lighting device according to any one of the first to third aspects, wherein, in selecting the current adjustment algorithm, the control unit determines characteristics of the input data based on pattern information indicating the light emission pattern included in the input data acquired by the acquisition unit, and selects the current adjustment algorithm based on the determined characteristics of the input data.

[0083] A lighting device according to a fifth aspect of the present invention is the lighting device according to any one of the first to fourth aspects, wherein, in selecting the current adjustment algorithm, the control unit determines characteristics of the input data acquired by the acquisition unit based on a trained model indicating a relationship between pattern information indicating the light emission pattern included in the input data and characteristics of the input data, and selects the current adjustment algorithm based on the determined characteristics of the input data.

[0084] A lighting device according to a sixth aspect of the present invention is the lighting device according to any one of the first to fifth aspects, wherein, in determining whether the temperature of the light source satisfies the predetermined condition, the control unit determines that the temperature of the light source satisfies the predetermined condition when the temperature of the light source detected by the detection unit exceeds a predetermined threshold.

[0085] A lighting device according to a seventh aspect of the present invention is the lighting device according to any one of the first to fifth aspects, wherein, in determining whether the temperature of the light source satisfies the predetermined condition, the control unit predicts whether the temperature of the light source will exceed a predetermined threshold based on the temperature of the light source detected by the detection unit and a change in the temperature of the light source over time, and determines that the temperature of the light source satisfies the predetermined condition when it is predicted that the temperature of the light source will exceed the predetermined threshold.

[0086] A lighting device according to an eighth aspect of the present invention is the lighting device according to any one of the first to seventh aspects, wherein, when the control unit determines, in selecting the current adjustment algorithm, that the characteristics of the input data acquired by the acquisition unit are a mixture of character information and graphic information, the control unit divides the light source into an area where light-emitting elements corresponding to the character information are present and an area where light-emitting elements corresponding to the graphic information are present, and selects a current adjustment algorithm that differs from each other for each divided area.

[0087] A control method according to a ninth aspect of the present invention is a control method for a lighting device including a light source having a plurality of light-emitting elements arranged in an array, a projection lens that projects light emitted by the light source, and a detection unit that detects a temperature of the light source, the control method comprising the steps of: acquiring input data regarding the 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 or not the temperature of the light source satisfies a predetermined condition based on the detected temperature of the light source; if it is determined that the temperature of the light source satisfies 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 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. [Explanation of symbols]

[0088] 100 Lighting Equipment 110 Light source 111 Light emitting element 120 Projection Lens 130 Acquisition Department 140 Control section 150 Detector

Claims

1. a light source having a plurality of light emitting elements arranged in an array; a projection lens that projects light emitted by the light source; an acquisition unit that acquires input data relating to a light emission pattern of the plurality of light emitting elements; a control unit that individually controls a current to be supplied to each of the plurality of light-emitting elements based on the input data acquired by the acquisition unit; a detection unit that detects a temperature of the light source, The control unit is determining whether or not the temperature of the light source satisfies a predetermined condition based on the temperature of the light source detected by the detection unit; when it is determined that the temperature of the light source satisfies the predetermined condition, selecting a current adjustment algorithm for adjusting an 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; adjusting the amount of current supplied to each of the plurality of light-emitting elements based on the selected current adjustment algorithm; Lighting equipment.

2. When the control unit determines that the characteristic of the input data acquired by the acquisition unit is character information, in selecting the current adjustment algorithm, the control unit selects, as the current adjustment algorithm, an algorithm in which the amount of current after adjustment gradually increases in a downwardly convex curve as the amount of current before adjustment increases.

10. The lighting device of claim 1.

3. When the control unit determines that the characteristic of the input data acquired by the acquisition unit is graphic information in the selection of the current adjustment algorithm, the control unit selects, as the current adjustment algorithm, an algorithm in which the amount of current after adjustment gradually increases in an upwardly convex curve as the amount of current before adjustment increases.

10. The lighting device of claim 1.

4. The control unit, in selecting the current adjustment algorithm, determines a characteristic of the input data based on pattern information indicating the light emission pattern included in the input data acquired by the acquisition unit, and selects the current adjustment algorithm based on the determined characteristic of the input data.

10. The lighting device of claim 1.

5. The control unit, in selecting the current adjustment algorithm, determines characteristics of the input data acquired by the acquisition unit based on a trained model indicating a relationship between pattern information indicating the light emission pattern included in the input data and characteristics of the input data, and selects the current adjustment algorithm based on the determined characteristics of the input data.

10. The lighting device of claim 1.

6. the control unit determines that the temperature of the light source satisfies the predetermined condition when the temperature of the light source detected by the detection unit exceeds a predetermined threshold in determining whether the temperature of the light source satisfies the predetermined condition.

6. An illumination device according to claim 1.

7. the control unit, in determining whether the temperature of the light source satisfies the predetermined condition, predicts whether the temperature of the light source will exceed a predetermined threshold based on the temperature of the light source detected by the detection unit and a change in the temperature of the light source over time, and determines that the temperature of the light source satisfies the predetermined condition when it predicts that the temperature of the light source will exceed the predetermined threshold.

6. An illumination device according to claim 1.

8. When the control unit determines that the characteristics of the input data acquired by the acquisition unit are a mixture of character information and graphic information in the selection of the current adjustment algorithm, the control unit divides the light source into an area in which a light emitting element corresponding to the character information exists and an area in which a light emitting element corresponding to the graphic information exists, and selects a current adjustment algorithm different from each other for each divided area.

6. An illumination device according to claim 1.

9. 1. A method for controlling a lighting device including a light source having a plurality of light-emitting elements arranged in an array, a projection lens that projects light emitted by the light source, and a detection unit that detects a temperature of the light source, comprising the steps of: acquiring input data relating to a light emission pattern of the plurality of light emitting elements; Based on the acquired input data, a current supplied to each of the plurality of light-emitting elements is individually controlled; determining whether the temperature of the light source satisfies a predetermined condition based on the detected temperature of the light source; selecting a current adjustment algorithm for adjusting an amount of current supplied to each of the plurality of light-emitting elements based on a characteristic of the acquired input data when it is determined that the temperature of the light source satisfies the predetermined condition; adjusting the amount of current supplied to each of the plurality of light-emitting elements based on the selected current adjustment algorithm; Control methods.

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