JP5645200B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device, and more particularly to a lighting device using a light emitting diode (LED) as a light source.

  Conventional lighting devices generally use incandescent bulbs or fluorescent lamps, such as turning on / off, dimming by adjusting output, turning on a night light (bean bulb), and the like.

  In recent years, the evolution of light emitting diodes (LEDs) has been remarkable, and LEDs having various luminance outputs with high luminance and high output have been put into practical use. In such an illuminating device using LEDs, the user can freely change the color tone of the illumination by adjusting each output by combining LEDs with different wavelengths in addition to operations such as turning on and off. Is possible.

  Japanese Patent Laid-Open No. 2008-305759 discloses a method for adjusting the duty ratio of a PWM signal for driving an LED with respect to adjustment of the output of the LED.

JP 2008-305759 A

  However, in general, when adjusting the output of the LED, the duty ratio is adjusted on the assumption that the duty ratio of the PWM signal and the output of the LED are in an ideal linear relationship. The line may be different from the ideal.

  Therefore, even when the duty ratio is adjusted so as to obtain a desired output from the LED, there is a problem that high-precision light control cannot be performed because it differs from the actual output.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an illumination device capable of highly precise light control.

  An illuminating device according to an aspect of the present invention includes a light emitting unit, a lighting circuit that turns on the light emitting unit, and a control circuit that performs a lighting control for a periodic cycle period that includes a lighting period that turns off the light emitting unit. Prepare. The control circuit sets the lighting period according to the desired dimming rate based on the characteristic data of the dimming rate according to the lighting period for the light emitting unit measured in advance.

  Preferably, the control circuit sets the lighting period according to the desired dimming rate based on the approximate expression of the characteristic data.

  In particular, the characteristic data is divided into a plurality of areas defined by the range of dimming rate. An approximate expression of the characteristic data in each region is calculated. The control circuit sets the lighting period according to the desired dimming rate based on the calculated approximate expression corresponding to the range to which the desired dimming rate belongs.

  According to said structure, the control circuit in an illuminating device sets to the lighting period according to a desired light control rate based on the characteristic data of the light control rate according to the lighting period with respect to the light emission part measured beforehand. Therefore, since the lighting period, which is the duty ratio, is set based on the actually measured characteristic data, it is possible to perform high-level light control.

It is an external appearance block diagram of the illuminating device 1 according to embodiment of this invention. It is a schematic block diagram explaining the hardware of the illuminating device 1 according to embodiment of this invention. It is a figure explaining the structure of LED module 31, 32 according to embodiment of this invention. It is a figure explaining an example in case LED module 31, 32 is arrange | positioned at the illuminating device 1. FIG. It is an external appearance block diagram of the remote control 50 according to embodiment of this invention. It is a schematic block diagram explaining the hardware of remote control 50 according to the embodiment of the present invention. It is a figure explaining the production | generation of the PWM pulse output from the PWM control circuit 23 according to embodiment of this invention. It is a figure explaining the change of the light control rate of LED module 31 and 32 at the time of adjusting the duty ratio of the lighting period Ton in the period T of the PWM pulse according to embodiment of this invention. It is a figure explaining the relationship between the light control rate actually measured with respect to LED module 31 (daylight color LED) according to embodiment of this invention, and a PWM pulse value. It is a figure explaining the relationship between the light control rate actually measured with respect to LED module 32 (bulb color LED) according to embodiment of this invention, and a PWM pulse value. It is a figure explaining the approximate expression of the output characteristic line of LED modules 31 and 32. FIG. It is a flowchart explaining the output of the PWM pulse in consideration of the dispersion | variation in the output characteristic of LED module 31 according to embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

FIG. 1 is an external configuration diagram of lighting apparatus 1 according to the embodiment of the present invention.
Referring to FIG. 1, lighting device 1 according to the embodiment of the present invention may be provided with chassis 2 for attaching the main body and covers 8 and 9 that cover the entire surface of the main body together with chassis 2. It is shown. In this example, as an example, it is assumed that the chassis 2 of the lighting device 1 is attached to the ceiling.

  The cover 8 is provided corresponding to a region where the LED module for illumination is arranged. Light is irradiated from the region of the cover 8.

  Another cover 9 provided near the center of the cover 8 is provided corresponding to a region where a control device such as a substrate for controlling the LED module is disposed. The region corresponding to the cover 9 is not irradiated with light because no LED module is provided.

  In addition, a portable remote controller 50 for operating the lighting device 1 is provided. By operating the remote controller 50, it becomes possible to give various operation instructions to the illumination device 1. Details of the remote controller 50 will be described later.

  FIG. 2 is a schematic block diagram illustrating hardware of lighting apparatus 1 according to the embodiment of the present invention.

  Referring to FIG. 2, lighting device 1 according to the embodiment of the present invention includes a power supply circuit 10, a lighting control unit 20, a lighting unit 30, and an interface unit 40.

  The power supply circuit 10 receives an AC power input (AC input) (100 V), converts it into a DC voltage, and supplies the voltage to each part of the apparatus. In this example, the voltage is supplied to only the control power supply circuit 21 and the illumination unit 30 as an example. However, the voltage is not limited to this, and the voltage necessary for other parts is also shown. Shall be supplied.

  The illumination control unit 20 includes a control power supply circuit 21 that adjusts the voltage supplied from the power supply circuit 10 to the CPU 22, a CPU (Central Processing Unit) 22 that controls the entire illumination device 1, and a PWM ( (Pulse Width Modulation) control circuit 23, signal receiving unit 25, SW input unit 26, illuminance sensor 28, and memory 29 are included. The CPU 22, the memory 29, and the PWM control circuit 23 are configured by a microcomputer.

  CPU22 is connected with each part and instruct | indicates operation | movement required in order to control the illuminating device 1 whole.

  The PWM control circuit 23 generates a PWM pulse necessary for driving the LED modules 31 and 32 in accordance with an instruction from the CPU 22.

  The signal receiving unit 25 is connected to the infrared light receiving unit 41 included in the interface unit 40, and outputs an instruction in response to the infrared signal received by the infrared light receiving unit 41 to the CPU 22.

  The SW input unit 26 is connected to the operation SW (switch) 42 and outputs an instruction in response to the operation of the operation SW to the CPU 22.

  The illuminance sensor 28 measures the illuminance around the lighting device 1 and outputs it to the CPU 22. The CPU 22 can control the dimming rate based on the measurement result from the illuminance sensor 28.

  The memory 29 stores various programs for controlling the lighting device 1 and initial values, and is also used as a working memory for the CPU 22.

  The illumination unit 30 includes LED modules 31 and 32 having different color temperatures, and FET (Field Effect Transistor) switches 33 and 34 used to drive the LED modules 31 and 32. In this example, the color temperature of the LED module 31 is about 6700K, and the color temperature of the LED module 32 is about 2700K. Hereinafter, the LED module 31 is also referred to as daylight color LED (simply daylight color). The LED module 32 is also referred to as a light bulb color LED (simply a light bulb color). Here, the case where the LED modules 31 and 32 are provided as one set each is shown, but a configuration in which a plurality of sets are provided is also possible. Further, the FET switches 33 and 34 may be in the PWM control circuit 23.

The interface unit 40 includes an infrared light receiving unit 41 and an operation SW 42.
The infrared light receiving unit 41 receives an infrared signal from the remote controller 50 described above. The infrared signal is photoelectrically converted and output to the signal receiving unit 25.

  The operation SW 42 includes a power switch and the like, and an instruction in response to a switch operation of the user such as a power switch is output to the CPU 22 via the SW input unit 26. Note that when the power switch is on, necessary power is supplied to the lighting device 1, and when the power switch is off, power is not supplied to the lighting device 1. The various operations in this example are assumed to be when the power switch is on.

  FIG. 3 is a diagram illustrating a configuration of LED modules 31 and 32 according to the embodiment of the present invention.

  Referring to FIG. 3, CPU 22 instructs PWM control circuit 23 to generate and output PWM pulses S <b> 1 and S <b> 2 for driving at least one of LED modules 31 and 32.

  The LED modules 31 and 32 are supplied with a necessary voltage from the power supply circuit 10. FET switches 33 and 34 are provided between the LED modules 31 and 32 and the ground voltage GND, respectively.

  Then, the FET switches 33 and 34 are turned on / off in response to the PWM pulses S1 and S2, whereby current is supplied / cut off to the LED modules 31 and 32. When current is supplied to the LED modules 31 and 32, the LED modules 31 and 32 emit light. In addition, although the structure which drives the LED modules 31 and 32 was demonstrated here, it is the same also when the other LED module is provided with two or more.

  FIG. 4 is a diagram for explaining an example when the LED modules 31 and 32 are arranged in the lighting device 1.

  Referring to FIG. 4, a case where LED modules 31 and 32 are arranged adjacent to each other and arranged in a plurality of sets of circular shapes is shown. By mounting the LED modules 31 and 32 having different color temperatures adjacent to each other, it is possible to easily mix the light emitted from the respective LED modules, and to eliminate color variation and unevenness on the irradiation surface.

FIG. 5 is an external configuration diagram of remote controller 50 according to the embodiment of the present invention.
Referring to FIG. 5, remote controller 50 is provided with a liquid crystal panel 52 and various buttons. The liquid crystal panel 52 can also use a display device other than the liquid crystal.

  Here, a plurality of buttons are provided. Specifically, a “lighting” button 54, a “daylight color / bulb color” switching button 56, an “illuminance sensor” button 70, and a “+/−” button 74 for instructing to increase or decrease a numerical value or the like are provided. It is done.

  Here, a plurality of buttons are provided. Specifically, an “all light” button 54, an “extinguish” button 53, an “up” button 57A and a “down” button 57B for instructing to increase or decrease the dimming rate, a “bulb color” button 59A and A “daylight color” button 59B, an “illuminance sensor” button 70, and a “+/−” button 74 for instructing to increase or decrease a numerical value or the like are provided.

  When the user presses the “all lights” button 54, a full lighting control instruction is output from the remote controller 50. In response to the input of the full lighting control instruction from the remote controller 50, the CPU 22 of the lighting device 1 instructs the PWM control circuit 23 to start full lighting control on the lighting unit 30. As a result, light having a dimming rate of 100% is emitted from the illumination unit 30 in accordance with the pressing of the “all lights” button 54, that is, the input of the full lighting control instruction from the remote controller 50.

  The dimming rate of the light emitted from the illuminating unit 30 is changed gradually from all the lamps (100% dimming rate) to the low light (30% dimming rate) by operating the “up” button 57A and “down” button 57B. Adjusted up to. Specifically, for example, when the “down” button 57B is pressed in a state where the “full light” button 54 is pressed and all the lights are turned on (dimming rate 100%), the half light (the dimming rate 50%) is obtained. In this state, when the “down” button 57B is pressed, the light is dimmed (the light control rate is 30%). In addition, when the “UP” button 57A is pressed in this state, the light is half-lit (dimming rate 50%), and when the “UP” button 57A is pressed in this state, all the lights are turned on (dimming rate 100%). . It is assumed that the current dimming rate is stored in the memory 29.

  When the user presses the “light-off” button 53 while the light is on, a light-off control instruction is output from the remote controller 50. The CPU 22 of the lighting device 1 receives the input of the turn-off control instruction from the remote controller 50 and instructs the PWM control circuit 23 to turn off the lighting unit 30. As a result, the irradiation of light from the illumination unit 30 is completed in accordance with the pressing of the “light-off” button 53, that is, according to the input of the light-off control instruction from the remote controller 50.

  Further, when the user presses the “bulb color” button 59A and the “daylight color” button 59B, a color tone switching instruction is output from the remote controller 50. The CPU 22 of the lighting device 1 receives an input of a color tone switching instruction from the remote controller 50 and instructs the PWM control circuit 23 to switch lighting to the lighting unit 30. Here, it is assumed that the color tone of the light emitted from the illumination unit 30 can be adjusted in accordance with the pressing of the “bulb color” button 59A and the “daylight color” button 59B, that is, the input of the color tone switching instruction from the remote controller 50. Specifically, when the “bulb color” button 59A is pressed, the dimming rate is set so that the daylight color is gradually switched to the light bulb color while maintaining the dimming rate. For example, when the “bulb color” button 59A is pressed in the state of “daylight color”, which is all daylight color lights (dimming rate 100%), the daylight color is dimming rate 70% and the light bulb color is dimming rate 30%. It is set to “half-daylight color”, and the color is changed from the daylight color to the light bulb color side while maintaining the dimming rate. In this state, when the “bulb color” button 59A is further pressed, the daylight color is set to “half-bulb color” with a dimming rate of 30% and the bulb color is set to 70%, and the dimming rate is maintained. The color is further changed from daylight to the light bulb color. In addition, when the “daylight color” button 59B is pressed, the dimming rate is set to be switched in a stepwise manner from the light bulb color to the daylight color while maintaining the dimming rate. For example, when the “daylight color” button 59B is pressed in the state of “bulb color” that is all light bulb colors (light control rate 100%), the light bulb color is dimming rate 70% and the daylight color is dimming rate 30%. The “half-bulb color” is set to change the color tone from the light bulb color to the daylight color side while maintaining the dimming rate. In this state, when the “daylight color” button 59B is further pressed, the color of the light bulb is set to “half-daylight” with a dimming rate of 30% and the daylight color is set to 70% of the dimming rate. Is further changed from the light bulb color to the daylight color side. It is assumed that the current color tone is stored in the memory 29.

  According to the operation, the user operates the “up” button 57A and the “down” button 57B or the “bulb color” button 59A and the “daylight color” button 59B to change the dimming rate and the color tone to the user's preference. It is possible to realize a light environment.

  Further, when the user presses the “illuminance sensor” button 70, an instruction to operate the illuminance sensor is output from the remote controller 50. The CPU 22 of the lighting device 1 receives an operation instruction for the illuminance sensor 28 from the remote controller 50 and acquires the measurement result measured by the illuminance sensor 28. Then, the CPU 22 controls the dimming rate based on the measurement result acquired from the illuminance sensor 28. For example, based on the measurement result of the illuminance sensor 28, when it is determined that the indoor environment such as a room is sufficiently bright due to the incident sunlight (natural light), the illuminance is reduced by reducing the set dimming rate. It is possible to adjust. As a result, power consumption can be reduced. On the other hand, when sunlight (natural light) is blocked and the indoor environment such as a room is judged to be dark, an appropriate illuminance can be obtained by increasing the dimming rate again up to the set dimming rate. It is possible to adjust so that. Further, when the user presses the “illuminance sensor” button 70 again, an instruction to stop the operation of the illuminance sensor is output from the remote controller 50. The CPU 22 of the illumination device 1 receives an instruction to stop the operation of the illuminance sensor 28 from the remote controller 50 and stops the control of the light control rate based on the measurement result measured by the illuminance sensor 28. This makes it possible to set the dimming rate desired by the user regardless of the measurement result of the illuminance sensor 28.

  FIG. 6 is a schematic block diagram illustrating hardware of remote control 50 according to the embodiment of the present invention.

  Referring to FIG. 6, remote control 50 according to the embodiment of the present invention includes a power supply circuit 51, a remote control control unit 55, and an interface unit 56.

  The power supply circuit 51 receives power from a battery such as a secondary battery and supplies a voltage to each unit of the apparatus. In this example, the voltage is shown to be supplied only to the control power supply circuit 81 as an example. However, the present invention is not limited to this, and a necessary voltage is supplied to other parts. Shall.

  The remote controller controller 55 controls a control power supply circuit 81 for adjusting the voltage supplied from the power circuit 51 to the CPU 86, a CPU (Central Processing Unit) 86 for controlling the entire remote controller 50, and the liquid crystal panel 52. Includes a liquid crystal driving circuit 82, a signal transmission unit 84, a SW input unit 83, and a memory 80.

  The CPU 86 is connected to each unit and instructs an operation necessary for controlling the entire remote controller 50.

  The liquid crystal driving circuit 82 drives the liquid crystal panel 52 that displays a desired screen in accordance with an instruction from the CPU 86.

  The signal transmission unit 84 outputs an instruction from the CPU 86 to the infrared light projecting unit 87 included in the interface unit 56.

  The SW input unit 83 is connected to the operation SW (switch) 88 and outputs an instruction in response to the operation of the operation SW to the CPU 86.

  The memory 80 stores a program for controlling the remote controller 50, initial values, and the like, and is also used as a working memory for the CPU 86.

  The interface unit 56 includes an infrared light projecting unit 87, an operation SW 88, and the liquid crystal panel 52.

  The infrared light projecting unit 87 converts the signal output from the signal transmission unit 84 into an infrared signal and projects the light onto the illumination device 1.

  The operation SW 88 includes various buttons provided on the remote controller 50 described above. Specifically, an “all light” button 54, an “extinguish” button 53, an “up” button 57A and a “down” button 57B for instructing to increase or decrease the dimming rate, a “bulb color” button 59A and A “daylight color” button 59B, an “illuminance sensor” button 70, and a “+/−” button 74 for instructing to increase or decrease a numerical value or the like are provided.

  The CPU 86 of the remote controller 50 receives an input instruction of each button in the operation SW 88 via the SW input unit 83 and instructs the signal transmission unit 84 to output a transmission signal corresponding to each button. In response to an instruction from the CPU 86, the signal transmission unit 84 outputs a transmission signal corresponding to each button to the illumination device 1 through the infrared projection unit 87 as an infrared signal. The infrared light receiving unit 41 of the illumination device 1 receives the infrared signal projected from the infrared light projecting unit 87 of the remote controller 50. The infrared light receiving unit 41 photoelectrically converts the received infrared signal. Then, the signal receiving unit 25 outputs a transmission signal instructed from the remote controller 50 obtained by photoelectric conversion to the CPU 22. With this operation, the CPU 22 executes an operation according to an input instruction from the remote controller 50.

  Specifically, as described above, when the user presses the “up” button 57A or the “down” button 57B, the CPU 22 adjusts the dimming rate according to the light emission of the LED modules 31 and 32 in the illumination unit 30.

  For example, as the “down” button 57B is pressed in a state where all the lamps are in the dimming state (100% dimming rate), the state changes from “all lighting” → “half-lighting” → “lighting”, and the state (lighting rate 30) %) As the “Up” button 57A is pressed, “light” → “half light” → “full light” changes.

  Further, as described above, when the user presses the “bulb color” button 59A or the “daylight color” button 59B, the CPU 22 adjusts the color tone according to the light emission of the LED modules 31 and 32 in the illumination unit 30. For example, “Daylight color” → “Semilight color” → “Semibulb color” → “Lightbulb color” as the “bulb color” button 59A is pressed in the state of “daylight color” which is all daylight colors (dimming rate 100%) In this state (light bulb color), “bulb color” → “half light bulb color” → “half light color” → “day light color” changes as the “daylight color” button 59B is pressed.

  In the present example, the portable remote controller 50 has been described. However, the present invention is not limited to this, and a fixed remote controller provided on the wall surface may be used. Further, the remote controller may be provided as a part of the interface unit 40 of the lighting device 1. In that case, it is also possible to adopt a configuration in which the instruction signal from the operation SW is directly transmitted using a signal line instead of transmitting the operation SW signal by an infrared signal. In addition, transmission / reception of signals is not limited to infrared rays, and wireless or the like may be used.

Next, lighting on / off control of the LED module according to the embodiment of the present invention will be described.
The PWM control circuit 23 according to the embodiment of the present invention controls PWM pulses S1 and S2 output to the LED modules 31 and 32 in accordance with an instruction from the CPU 22. More specifically, the FET switch 33 is turned on according to the ON period of the PWM pulse S1, and the LED module 31 is lit. Further, the LED module 31 in which the FET switch 33 is non-conductive is turned off according to the OFF period of the PWM pulse S1.

  Similarly, the LED module 32 is turned on / off by the FET switch 34 being turned on / off in accordance with the PWM pulse S2 from the PWM control circuit 23.

  Although not shown, the CPU 22 is connected to a crystal oscillator that outputs an oscillation signal of 40 MHz (one cycle 25 ns), and the PWM control circuit 23 outputs PWM pulses S1 and S2 in accordance with an instruction according to timing synchronized with the oscillation signal. To do.

  FIG. 7 is a diagram illustrating generation of a PWM pulse output from the PWM control circuit 23 according to the embodiment of the present invention.

  Referring to FIG. 7, PWM pulses S1 and S2 output from PWM control circuit 23 are set according to the number of periods (here, Z), with one period 25 ns being the minimum unit of the oscillation signal as a minimum unit. The Here, the case where it sets about the lighting period Ton and the light extinction period Toff is shown.

  The lighting period Ton when the dimming rate is 100% is set with a certain margin so that the current supplied to the LED modules 31, 32, etc. does not exceed the rated current of the LED modules 31, 32, etc.

  Then, the cycle period T including the lighting period Ton and the extinguishing period Toff is set somewhat longer than the lighting period when the dimming rate is 100%. Therefore, for example, it is possible to set the lighting period Ton somewhat longer than the lighting period at which the dimming rate is 100%, and by supplying a current close to the rated current to the LED modules 31, 32, etc., 100% It is also possible to set the above dimming rate.

  On the other hand, as described above, when the duty ratio of the lighting period Ton in the period T is adjusted to adjust the dimming rate of the LED modules 31 and 32, the actual dimming is performed due to variations in the output characteristics of the LED modules 31 and 32. It may be different from the light rate.

  FIG. 8 is a diagram illustrating a change in the dimming rate of the LED modules 31 and 32 when the duty ratio of the lighting period Ton in the period T of the PWM pulse according to the embodiment of the present invention is adjusted.

  Referring to FIG. 8, ideally, it is desirable that the dimming rate change linearly when the duty ratio of the lighting period Ton in the period T of the PWM pulse is changed linearly. In general, the duty ratio of the PWM pulse is calculated according to a linear output characteristic line (ideal) where the dimming rate is 100% when the duty ratio of the PWM pulse is 100%.

  However, the output characteristic line of the dimming rate of the actual LED modules 31 and 32 is different from the ideal output characteristic line as shown in the figure.

  Therefore, in calculating the duty ratio of the PWM pulse according to the dimming rate, when the duty ratio is set by an ideal output characteristic line, there is a possibility that the dimming rate is different from the desired dimming rate. There is.

  FIG. 9 is a diagram illustrating the relationship between the dimming rate actually measured for the LED module 31 (daylight color LED) according to the embodiment of the present invention and the PWM pulse value.

  Referring to FIG. 9, here, an output characteristic line in the case where the vertical axis is a PWM pulse value (number of cycles) and the horizontal axis is a dimming rate (%) is shown.

  In this example, as an example, when the PWM pulse value is 1670, the duty ratio of the lighting period Ton is set to 100%.

  FIG. 10 is a diagram illustrating the relationship between the dimming rate actually measured for the LED module 32 (bulb color LED) and the PWM pulse value according to the embodiment of the present invention.

  Referring to FIG. 10, here, the output characteristic line when the vertical axis is the PWM pulse value (number of cycles) and the horizontal axis is the dimming rate (%) is shown.

FIG. 11 is a diagram for explaining an approximate expression of the output characteristic lines of the LED modules 31 and 32.
Referring to FIG. 11, there are shown an approximate expression of daylight color LED according to the output characteristic line of LED module 31 of FIG. 9 and an approximate expression of bulb color LED according to the output characteristic line of LED module 32 of FIG.

  Here, regarding the approximate expression of daylight color LED, the case where the dimming rate according to the output characteristic line shown in FIG. 9 is divided into four areas and the approximate expression in each area is calculated is shown. As an example, “light control rate 0 to 60.0%”, “light control rate 60.1% to 91.0%”, “light control rate 91.1% to 98.0%”, “light control rate 98” .1% to 100.0% "is shown. Here, there is shown a case where the approximate expression is further transformed into an arithmetic expression in order to facilitate processing by the CPU 22. The CPU 22 can calculate a desired PWM pulse value according to the actual output characteristic line of the LED module 31 by inputting a desired dimming rate as a variable using the arithmetic expression.

  Similarly, regarding the approximate expression of the daylight color LED, the case where the dimming rate according to the output characteristic line shown in FIG. 10 is divided into four areas and the approximate expression in each area is calculated is shown. As an example, “light control rate 0 to 82.5%”, “light control rate 82.6% to 97.0%”, “light control rate 97.1% to 99.9%”, “light control rate 100” The case of dividing into “%” is shown. Here, there is shown a case where the approximate expression is further transformed into an arithmetic expression in order to facilitate processing by the CPU 22. The CPU 22 can calculate a desired PWM pulse value according to the actual output characteristic line of the LED module 32 by inputting a desired dimming rate as a variable using the arithmetic expression. In FIGS. 9 and 10, the approximate characteristic line using the arithmetic expression is indicated by a bold line.

  That is, it is possible to set a desired dimming rate by calculating a PWM pulse value corresponding to the dimming rate, that is, a duty ratio of the PWM pulse, based on the arithmetic expression. Therefore, it is possible to perform dimming with high accuracy, and it is possible to realize a more comfortable light environment in consideration of variations in output characteristics of the LED module.

  As shown in the output characteristic line of FIG. 10, the dimming rate is 100% before the PWM pulse value is 1670, that is, before the duty ratio of the lighting period Ton is 100%. ing.

  Therefore, the approximate expression in FIG. 10 shows a case where the approximate expression is calculated according to the output characteristic line until the dimming rate exceeds 100% up to the dimming rate of 99.9%. When the dimming rate is 100.0%, the PWM pulse value is 1670. That is, an approximate expression is calculated using only necessary output characteristic lines. Thereby, for example, in this example, it is not necessary to increase the value of the PWM pulse value unnecessarily, and the power consumption can be reduced by suppressing the duty ratio.

  FIG. 12 is a flowchart illustrating PWM pulse output in consideration of variations in output characteristics of LED module 31 according to the embodiment of the present invention.

  This flow is executed when the CPU 22 reads a program stored in the memory 29.

  Referring to FIG. 12, CPU 22 determines whether the dimming rate is within a range of 0% to 60.0% (step S70).

  Next, when the CPU 22 determines that the dimming rate is in the range of 0% to 60.0% (YES in step S70), the CPU 22 calculates the PWM pulse value based on the arithmetic expression (1). Then, a PWM pulse is output based on the calculated PWM pulse value. And it returns to step S70 again.

  If the CPU 22 determines that the dimming rate is not within the range of 0% to 60.0% (NO in step S70), then the dimming rate is 60.1% to 91.0%. It is determined whether it is within the range (step S76). In step S76, when the CPU 22 determines that the dimming rate is in the range of 60.1% to 91.0%, the CPU 22 calculates the PWM pulse value based on the arithmetic expression (2) (step S78). . Then, a PWM pulse is output based on the calculated PWM pulse value. And it returns to step S70 again.

  If the CPU 22 determines that the dimming rate is not within the range of 0% to 60.0% (NO in step S70), then the dimming rate is 91.1% to 98.0%. It is determined whether it is within the range (step S80). In step S80, when the CPU 22 determines that the dimming rate is in the range of 91.1% to 98.0%, the CPU 22 calculates the PWM pulse value based on the arithmetic expression (3). Then, a PWM pulse is output based on the calculated PWM pulse value. And it returns to step S70 again.

  If CPU 22 determines that the dimming rate is not within the range of 91.1% to 98.0% (NO in step S80), then the dimming rate is 98.1% to 100.0. It is judged whether it is in the range of% (step S84). In step S84, when the CPU 22 determines that the dimming rate is in the range of 98.1% to 100.0%, the CPU 22 calculates the PWM pulse value based on the arithmetic expression (4). Then, a PWM pulse is output based on the calculated PWM pulse value. And it returns to step S70 again. If the CPU 22 determines in step S84 that the dimming rate is not within the range of 98.1% to 100.0%, the process returns to step S70.

  In this example, the output of the PWM pulse S1 in consideration of the variation in the output characteristics of the LED module 31 has been described. However, the same method is executed for the output of the PWM pulse S2 in consideration of the variation in the output characteristics of the LED module 32. Is possible.

  As a result of the processing, the PWM pulse value corresponding to the dimming rate, that is, the duty ratio of the PWM pulse can be calculated based on the arithmetic expression as described above. It becomes possible to realize a more comfortable light environment in consideration of variations in output characteristics.

  In this example, the case where the approximate expression is calculated and the output of the PWM pulse in consideration of the variation in the output characteristics of the LED module has been described. However, the present invention is not particularly limited to this, for example, the output characteristic line described above. Accordingly, a correspondence table storing a one-to-one correspondence between PWM pulse values and dimming rates may be used.

  It is also possible to provide a program that causes a computer to function and execute control as described in the above flow. Such a program can be read by a non-transitory computer such as a flexible disk attached to a computer, a CD-ROM (Compact Disk-Read Only Memory), a ROM (Read Only Memory), a RAM (Random Access Memory), and a memory card. It can also be recorded on a recording medium and provided as a program product. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network.

  The program may be a program module that is provided as part of an operating system (OS) of a computer and that calls necessary modules in a predetermined arrangement at a predetermined timing to execute processing. In that case, the program itself does not include the module, and the process is executed in cooperation with the OS. A program that does not include such a module can also be included in the program according to the present invention.

  The program according to the present invention may be provided by being incorporated in a part of another program. Even in this case, the program itself does not include the module included in the other program, and the process is executed in cooperation with the other program. Such a program incorporated in another program can also be included in the program according to the present invention.

  The provided program product is installed in a program storage unit such as a hard disk and executed. The program product includes the program itself and a recording medium on which the program is recorded.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Illumination device, 2 chassis, 8,9 cover, 10,51 power supply circuit, 20 illumination control part, 21,81 control power supply circuit, 23 PWM control circuit, 25 signal receiving part, 26, 83 SW input part, 28 Illuminance Sensor, 29 Memory, 30 Illumination unit, 31, 32 LED module, 33, 34 FET switch, 40, 56 Interface unit, 41 Infrared light receiving unit, 50 Remote control, 52 Liquid crystal panel, 55 Remote control unit, 82 Infrared light projecting unit, 82 liquid crystal drive circuit, 84 signal transmitter, 87 infrared light projector.

Claims (2)

A light emitting diode;
A control circuit for performing on / off control for a periodic period having a lighting period for turning on the light-emitting diode and a light-off period for turning off the light-emitting diode;
The control circuit, based on the characteristic data of the dimming rate according to the lighting period for the light emitting diode measured in advance, set to a lighting period according to a desired dimming rate ,
The said control circuit is an illuminating device set to the lighting period according to the said desired dimming rate based on the approximation formula of the said characteristic data . The characteristic data is divided into a plurality of areas defined by a range of dimming rate,
An approximate expression of the characteristic data in each region is calculated,
The lighting device according to claim 1, wherein the control circuit sets a lighting period according to the desired dimming rate based on a calculated approximate expression corresponding to a range to which the desired dimming rate belongs .

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