JP2018206701A - Lighting device - Google Patents

Abstract

To provide a lighting device which allows for light operation by a dimmer, even during fade-in.SOLUTION: A lighting device includes a lighting control section for adjusting a current supplied to a light source small/large or large/small according to large/small of the duty of an acquired lighting control signal, a storage section for storing the duty of the lighting control signal acquired before the lighting control section starts adjustment, a gradual increase section for gradually increasing the current supplied to the light source, toward a target current which must be adjusted by the lighting control section according to a duty stored in the storage section, an inhibition section for inhibiting operation of the gradual increase section when the duty of the lighting control signal, acquired anew while the gradual increase section is gradually increasing the current, is different from the duty stored in the storage section by a specified value or more, and an asymptotic section for making the current supplied to the light source asymptotic to a new target current which must be adjusted by the lighting control section according to the duty of the lighting control signal acquired anew, when the inhibition section inhibited operation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lighting device that lights a light source based on a signal from a dimmer.

  2. Description of the Related Art In recent years, lighting fixtures using LEDs (Light Emitting Diodes) as light sources have been widely used for applications such as residential use, business use, road use, and industrial use. The light source of the lighting fixture is driven by applying a DC voltage from, for example, a lighting device that converts a commercial AC voltage into a DC voltage.

  Conventionally, a dimmer for changing the magnitude of the light output of a light source has been provided. For example, the dimmer outputs a dimming signal indicating information corresponding to the operation of the dimming knob, and the lighting device that inputs the dimming signal outputs the light output of the light source according to the information indicated by the dimming signal. Change the size.

  For example, Patent Literature 1 discloses a lighting device that is connected to a controller (a dimmer) and that performs dimming of a light source unit by inputting a dimming signal including a PWM signal. In this lighting device, the light output of the light source unit linearly changes from 100% to 20% while the duty of the PWM signal changes from 5% to 90% in the continuous light control mode.

  Further, in Patent Document 2, fade-in that gradually increases the drive current of the light emitter to achieve the brightness indicated by the dimming signal from the dimmer, and light extinction by gradually decreasing the drive current of the light emitter. A lighting power supply circuit capable of fading out is described.

JP2015-32451A JP 2007-234415 A

  However, Patent Document 2 does not describe anything about processing when the brightness indicated by the dimming signal changes during fade-in or fade-out. If the dimmer knob is operated during actual fade-in or fade-out, the fade-in or fade-out will continue regardless of the operation of the knob, so the user may be slow to respond to dimming by the dimmer. There was a problem of being felt.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a lighting device capable of performing a simple dimming operation using a dimmer even during fade-in. It is in.

  A lighting device according to an aspect of the present invention acquires a dimming signal indicating the degree of adjustment of the light amount of a light source from the outside in a time series, and supplies a current based on the acquired dimming signal to the light source for lighting. In the lighting device, the dimming signal is a PWM signal, and when the duty of the acquired dimming signal is larger than the first threshold value and smaller than the second threshold value larger than the first threshold value, according to the magnitude of the duty A dimming unit that adjusts the current supplied to the light source to a small (or large) and a duty of a dimming signal acquired before the dimming unit starts adjustment is smaller than the second threshold (or the A storage unit that stores the duty of the acquired dimming signal, and the light source toward the target current to be adjusted by the dimming unit according to the duty stored in the storage unit. To supply the current When the duty of the dimming signal newly acquired while the gradually increasing part gradually increases the current is different from the duty stored in the storage part by a predetermined value or more, the operation of the gradually increasing part is A prohibition unit to be prohibited, and when the prohibition unit prohibits operation, the light control unit supplies the light source to a new target current to be adjusted according to the duty of the newly acquired light control signal And an asymptotic part that asymptotically causes a current to be generated.

  The present application can be realized not only as a lighting device including such a characteristic processing unit, but also as a lighting method using such characteristic processing as a step, or for causing a computer to execute such a step. It can be realized as a program. In addition, part or all of the lighting device can be realized as a semiconductor integrated circuit, or can be realized as a system including the lighting device.

  According to the above, it is possible to perform a light dimming operation by the dimmer even during fade-in.

It is a block diagram which shows the structural example of the lighting system containing the lighting device which concerns on embodiment of this invention. It is a timing chart which shows an example of the light control signal from a light control device, and the signal with respect to an integration circuit. It is a graph which shows the relationship between the duty of a light control signal, and the ratio of Itgt with respect to Imax. It is explanatory drawing which shows the structural example of the light control table for converting the duty of a light control signal. It is a graph which shows the time change of the electric current supplied to a light source during fade-in and fade-out. It is explanatory drawing which shows the structural example of the FIFO table which memorize | stored the ratio of the electric current made to increase / decrease. It is a graph which shows the time change of the electric current supplied to a light source when fade-in is interrupted. It is a graph which shows an example of the change curve of the electric current supplied to a light source after fade-in / fade-out interruption. It is a flowchart which shows the procedure of the initialization process by CPU. It is a flowchart which shows the process sequence of CPU which performs fade-in, light control, and fade-out. It is a flowchart which shows the procedure of the fixed-cycle process by CPU during fade-in and fade-out. It is a flowchart which shows the process sequence of CPU after interruption of fade-in and fade-out.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described. Moreover, you may combine arbitrarily at least one part of embodiment described below.

(1) The lighting device according to one aspect of the present invention acquires a dimming signal indicating the degree of adjustment of the light amount of the light source from the outside in time series, and supplies a current based on the acquired dimming signal to the light source. In the lighting device for lighting, the dimming signal is a PWM signal, and when the duty of the acquired dimming signal is larger than the first threshold and smaller than the second threshold larger than the first threshold, the magnitude of the duty is small And a light control unit that adjusts the current supplied to the light source to a small or large (or large or small), and the duty of the light control signal acquired before the light control unit starts adjustment is smaller than the second threshold value. (Or larger than the first threshold), the storage unit for storing the duty of the acquired dimming signal, and the target current to be adjusted by the dimming unit according to the duty stored in the storage unit Supply to the light source When the duty of the dimming signal newly acquired while the gradually increasing part gradually increases the current and the duty of the dimming signal newly obtained while the gradually increasing part gradually increases the current differs from the duty stored in the storage part by a predetermined value or more, A prohibiting unit for prohibiting operation, and when the prohibiting unit prohibits operation, the light source is directed toward a new target current to be adjusted by the dimming unit in accordance with a duty of the newly obtained dimming signal. And an asymptotic part for asymptotically supplying the current supplied to the capacitor.

  In this aspect, a dimming signal that is a PWM signal is acquired from the outside, and a current based on the acquired dimming signal is supplied to the light source to light it. When the duty of the dimming signal from the outside is within the range from the first threshold value to the second threshold value, the current supplied to the light source is reduced in accordance with the change (that is, increase and decrease) of the duty of the dimming signal. A first configuration that adjusts large (ie, decreases and increases) or a second configuration that adjusts the current supplied to the light source to large (that is, increases and decreases) is adopted. In the first configuration, it is determined whether or not the duty of the dimming signal acquired before starting the dimming is smaller than the second threshold. In the second configuration, the duty of the dimming signal acquired before starting the dimming is It is determined whether it is larger than the first threshold. When the determination is established, the determined duty is stored, and the current supplied to the light source is gradually increased toward the target current corresponding to the duty. When the duty of the dimming signal newly acquired while gradually increasing the current differs from the stored duty by a predetermined value or more, the gradual increase of the current supplied to the light source is stopped, and the newly acquired dimming signal The current supplied to the light source is made asymptotic toward a new target current according to the duty.

(2) Each time the dimming unit adjusts the current, the duty of the acquired dimming signal is greater than (or smaller than) the third threshold (or smaller than the first threshold). A diminishing unit that gradually decreases the current supplied to the light source by prohibiting the operation of the dimming unit, and the duty of the dimming signal newly acquired while the gradual decreasing unit gradually reduces the current is greater than the second threshold value. A second prohibiting unit that prohibits the operation of the gradual decrease unit when it is smaller (or greater than the first threshold), and the asymptotic unit further includes the new prohibition unit when the second prohibiting unit prohibits the operation. It is preferable that the current supplied to the light source is made asymptotic toward a new target current to be adjusted by the dimming unit in accordance with the duty of the dimming signal acquired in the above.

  In this aspect, each time the current supplied to the light source is adjusted according to the duty of the dimming signal acquired from the outside, in the first configuration, the duty of the acquired dimming signal is greater than or equal to the second threshold. In the second configuration, it is determined whether or not the duty of the acquired dimming signal is equal to or smaller than a third threshold value that is smaller than the first threshold value. When the determination is established, the current supplied to the light source is gradually decreased toward the target current corresponding to the determined duty. When the duty of the dimming signal newly acquired while gradually decreasing the current is smaller than the second threshold value in the first configuration or larger than the first threshold value in the second configuration, the current supplied to the light source is gradually decreased. Is stopped, and the current supplied to the light source is gradually made closer to a new target current corresponding to the duty of the dimming signal newly acquired while the current is gradually decreased.

(3) It is preferable that the asymptotic part gradually decreases the absolute value of the time change rate of the current supplied to the light source.

  In this aspect, the absolute value of the amount of change per unit time, that is, the absolute value of the slope of the current change is gradually reduced with respect to the current supplied to the light source so as to gradually approach the new target current. To do.

(4) The asymptotic part is configured to change the current supplied to the light source every predetermined time, and according to the magnitude of the difference between the new target current and the current supplied to the light source. It is preferable to adjust the amount of change in current that changes with time.

  In this aspect, when the current supplied to the light source is changed every predetermined time and gradually approaches a new target current, the difference between the new target current and the current supplied to the light source is The larger the value, the larger the amount of change in current per predetermined time.

(5) The table further includes a table that stores the duty of the dimming signal in association with the magnitude of the current adjusted by the dimming unit according to the duty, and the asymptotic unit includes the newly obtained dimming signal. It is preferable that the magnitude of the current stored in the table in association with the duty is the new target current.

  In this aspect, the magnitude of the current supplied to the light source is stored in the table in association with the duty of the dimming signal, and the table is referred to based on the newly acquired duty of the dimming signal. To determine a new target current.

[Details of the embodiment of the present invention]
A specific example of a lighting device according to an embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included. In addition, the technical features described in each embodiment can be combined with each other.

(Embodiment)
FIG. 1 is a block diagram illustrating a configuration example of a lighting system including a lighting device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a lighting device. The lighting device 1 acquires a dimming signal from the dimmer 3 in time series, and supplies a current based on the acquired dimming signal to the light source 4 to light it. The dimmer 3 outputs a dimming signal indicating the degree of adjustment of the light amount of the light source 4 to the lighting device 1 according to the rotation angle by rotating the knob (not shown) by the user. The light source 4 includes, for example, an LED, and the amount of light increases or decreases according to the increase or decrease of the supplied current.

  The lighting device 1 acquires a dimming signal from the dimmer 3 via the photocoupler 11, detects a duty ratio (hereinafter simply referred to as duty) of the acquired dimming signal, and outputs a PWM signal to the subsequent stage. A microcomputer (hereinafter referred to as a microcomputer) 10 is provided. The photocoupler 11 may be another circuit element or another circuit for transmitting the PWM signal (the same applies hereinafter).

  The microcomputer 10 includes a CPU (Central Processing Unit) 100. The CPU 100 includes a ROM (Read Only Memory) 110 that stores information such as a control program, a RAM (Random Access Memory) 120 that stores temporarily generated information, and a dimming signal to output a PWM signal. An input / output interface (I / O) 130 and a timer 140 for measuring elapsed time and the like are connected to each other by a bus. The ROM 110 stores a dimming table 111 (corresponding to a table) and a FIFO table 112 which will be described later. The RAM 120 has a storage area as a storage unit 121 described later.

  The lighting device 1 also includes an integration circuit 12 that integrates the PWM signal output from the microcomputer 10 and an operational amplifier (hereinafter referred to as an operational amplifier) 13 to which the output voltage of the integration circuit 12 is input. The operational amplifier 13 amplifies a difference between an output voltage of the integrating circuit 12 and a detection voltage of a resistor 17 described later. It should be noted that another photocoupler may be interposed between the microcomputer 10 and the integrating circuit 12 for insulation.

  The lighting device 1 further includes a converter control IC 15 for inputting the error voltage amplified by the operational amplifier 13 via the photocoupler 14, a DC / DC converter 16 whose voltage conversion is controlled by the control IC 15, and an AC power source. And a PFC (Power Factor Controller) circuit 20 that converts the AC voltage of 5 into a DC voltage and applies it to the DC / DC converter 16.

  The DC / DC converter 16 steps down the direct current voltage applied from the PFC circuit 20 and supplies the direct current to the light source 4 by applying the stepped down direct current voltage to the light source 4 through the resistor 17. The current supplied to the light source 4 is detected by the resistor 17, and the detection voltage thereby is input to the operational amplifier 13. Note that a connection point between the resistor 17 and the DC / DC converter 16 is connected to a reference potential which is a ground potential, for example.

  With the above configuration, the current flowing through the resistor 17 is controlled to be proportional to the output voltage of the integrating circuit 12. Since the output voltage of the integrating circuit 12 is proportional to the duty of the PWM signal output from the microcomputer 10, the current supplied to the light source 4 is proportional to the duty of the PWM signal output from the microcomputer 10 to the integrating circuit 12. To be controlled.

  Next, PWM signals input / output by the microcomputer 10 will be described. FIG. 2 is a timing chart showing an example of a dimming signal from the dimmer 3 and a signal for the integrating circuit 12. The dimming signal is shown in the upper part of the figure, and the signal for the integrating circuit 12 is shown in the lower part. In FIG. 2, the horizontal axis represents time (t), and the vertical axis represents the on / off state of the signal. The dimming signal is a PWM signal having a period of T1 (for example, 1 ms). The signal for the integrating circuit 12 is a PWM signal with a period of T2. In the example shown in FIG. 2, the duty of the dimming signal is 0.3.

  The dimming signal is a signal indicating the degree of adjustment of the light amount of the light source 4 by the duty. In many cases, the dimmer 3 covers from 5% to 90% as the duty specification of the dimming signal. In the present embodiment, the dimmer 3 is from 5% (corresponding to the first threshold) to 90% (to the second threshold). The current supplied to the light source 4 is adjusted to be small or large depending on the duty of the dimming signal within the range of change up to equivalent). That is, the current supplied to the light source 4 is decreased and increased (hereinafter also referred to as decrease / increase) in accordance with the increase and decrease (hereinafter also referred to as increase / decrease) of the light control signal. Specifically, when the duty of the dimming signal is D1, the maximum value (constant) of the current supplied to the light source 4 is Imax, and the current (variable) supplied to the light source 4 is Itgt, It is represented by Formula (1).

Itgt = Imax (1−D1 ′) (1)
However,
D1 '= (D1-0.05) × 0.95 / 0.85 (2)
(0.05 ≦ D1 ≦ 0.9)

  D1 ′ used in the equation (1) is obtained by converting from D1 by the equation (2) because the change range from 5% to 90% related to the duty D1 of the dimming signal is 0% related to D1 ′. This is because the mapping is evenly performed in the change range from 1 to 95%. As described above, the current supplied to the light source 4 is proportional to the duty of the PWM signal that the microcomputer 10 outputs to the integrating circuit 12. Here, when the duty of the PWM signal output from the microcomputer 10 is 1 and 0, the current supplied to the light source 4 can be Imax and 0, respectively. In this case, in order to supply the current represented by the equation (1) to the light source 4, D1 ′ is calculated by substituting the duty D1 of the dimming signal detected by the microcomputer 10 into the equation (2). A PWM signal having a duty of (1-D1 ′) may be output to the integrating circuit 12.

  Specifically, when the microcomputer 10 acquires the light control signal with a duty of 0.3 shown in the upper part of FIG. 2, the integration circuit 12 supplies the light source 4 with the current represented by the expression (1). On the other hand, a PWM signal having a duty of 0.72 shown in the lower part of FIG. The period of the output PWM signal may be an arbitrary length, but in this embodiment, the period is T2. In this way, the microcomputer 10 detects the duty D1 of the dimming signal, applies it to the equation (2), and applies the calculated D1 ′ to the equation (1) to output it to the integrating circuit 12. The duty of the power PWM signal can be calculated as a coefficient of Imax.

  In the above example, the current supplied to the light source 4 is adjusted to be small or large in accordance with the duty of the dimming signal. On the contrary, the light source 4 is adjusted in accordance with the duty of the dimming signal. The supplied current may be adjusted to be large or small. Itgt and D1 'in this case are represented by the following equations (3) and (4). D1 ′ used in the equation (3) is obtained by converting from D1 by the equation (4) because the change range from 5% to 90% related to the duty D1 of the dimming signal is changed to 5% related to D1 ′. This is for evenly mapping to the change range from 1 to 100%.

Itgt = Imax × D1 ′ (3)
However,
D1 ′ = (D1-0.05) × 0.95 / 0.85 + 0.05 (4)
(0.05 ≦ D1 ≦ 0.9)

  It should be noted that the current supplied to the light source 4 is limited to one that changes linearly with respect to the duty D1 of the dimming signal, as shown by the equations (1), (2) or (3), (4). Instead, it may be a curve that smoothly changes with respect to the duty D1.

  FIG. 3 is a graph showing the relationship between the duty of the dimming signal and the ratio of Itgt to Imax. In the figure, the horizontal axis represents the dimming signal duty (%), and the vertical axis represents Itgt / Imax (%). The solid line in the figure shows the characteristics when the current supplied to the light source 4 is adjusted to be small or large according to the duty of the dimming signal, and the broken line is according to the duty of the dimming signal. This shows characteristics when the current supplied to the light source 4 is adjusted to be large or small.

  In the case of the characteristic indicated by the solid line in FIG. 3, Itgt / Imax is 1−D1 ′ and D1 ′ is expressed by Equation (2) from Equation (1), so that the duty D1 of the dimming signal is 5%. When in the range up to 90%, Itgt / Imax is expressed as a point on a straight line with a slope of -0.95 / 0.85. The value of D1 'when the duty D1 of the dimming signal is smaller than 5% is fixed to 0, similar to the value calculated by the equation (2) when the duty is 5%. In this case, Itgt = Imax from equation (1). The value of D1 ′ when the duty D1 of the dimming signal is between 90% and 97% is fixed at 0.95, which is the same as the value calculated by equation (2) when the duty is 90%. To do. At this time, Itgt = 0.05 Imax from the equation (1).

  For example, when the duty of the dimming signal first captured by the microcomputer 10 is in the range of 5% to 90%, the microcomputer 10 determines the duty of the PWM signal output to the integrating circuit 12 using the formula (1). It can be calculated as a coefficient of Imax on the right side of. This duty corresponds to the target current magnitude. Thereby, the current supplied to the light source 4 is set to a target current within a range from Imax to 0.05Imax. In the present embodiment, the current supplied to the light source 4 is gradually increased at a constant increase rate within a fixed time (for example, 3 seconds) toward the calculated target current. Hereinafter, such control is referred to as Fade-In (FI).

  Thereafter, while the duty of the dimming signal increases / decreases within the range from 0% to 5%, the microcomputer 10 adjusts the duty of the PWM signal output to the integrating circuit 12 to 100%. Thereby, the current supplied to the light source 4 is adjusted to Imax. In addition, while the duty of the dimming signal increases / decreases within the range of 90% to 97%, the microcomputer 10 adjusts the duty of the PWM signal output to the integrating circuit 12 to 5%. Thereby, the current supplied to the light source 4 is adjusted to 0.05 Imax. Here, 97% may be a duty larger than 90% (second threshold) and smaller than 100%.

  After that, when the duty of the dimming signal becomes larger than 97% (corresponding to the third threshold value), the microcomputer 10 changes the duty of the PWM signal output to the integrating circuit 12 from 5% to 0%. Decrease gradually (see solid line with arrow in the figure). Thereby, the light source 4 is controlled so as not to be turned off suddenly. In FIG. 3, for the sake of convenience, the solid line is drawn so as to decrease to the right as the duty of the dimming signal becomes larger than 97%, but actually, the microcomputer 10 outputs the PWM output to the integrating circuit 12. The signal duty is gradually decreased from 5% to 0% at a constant decreasing rate within a certain time (for example, 3 seconds). Hereinafter, such control is referred to as Fade-Out (FO).

  On the other hand, in the case of the characteristics shown by the broken line in FIG. 3, Itgt / Imax is D1 ′ and D1 ′ is expressed by Expression (4) from Expression (3). When it is in the range up to 90%, Itgt / Imax is expressed as a point on a straight line having a slope of 0.95 / 0.85 shown in FIG. When the duty D1 of the dimming signal is in the range from 3% to 5%, the value of D1 ′ is fixed to 0.05 similarly to the value calculated by the expression (2) when the duty is 5%. . In this case, Itgt = 0.05Imax. Further, the value of D1 'when the duty D1 of the dimming signal is between 90% and 100% is fixed to 1 similarly to the value calculated by the equation (4) when the duty is 90%. In this case, Itgt = Imax from equation (3).

  For example, when the duty of the dimming signal first captured by the microcomputer 10 is in the range of 5% to 90%, the microcomputer 10 determines the duty of the PWM signal output to the integrating circuit 12 by the equation (3). Is calculated as a coefficient of Imax on the right side. This duty corresponds to the target current magnitude. As a result, the current supplied to the light source 4 is set to a target current within a range from 0.05 Imax to Imax. Also in this case, the current supplied to the light source 4 is gradually increased (fade-in) at a constant increase rate within a predetermined time toward the calculated target current.

  After that, while the duty of the dimming signal increases / decreases within the range of 3% to 5%, the microcomputer 10 adjusts the duty of the PWM signal output to the integrating circuit 12 to 5%. Thereby, the current supplied to the light source 4 is adjusted to 0.05 Imax. Further, while the duty of the dimming signal increases / decreases within the range of 90% to 100%, the microcomputer 10 adjusts the duty of the PWM signal output to the integrating circuit 12 to 100%. Thereby, the current supplied to the light source 4 is adjusted to Imax. Here, 3% may be a duty greater than 0% and smaller than 5% (first threshold).

  After that, when the duty of the dimming signal becomes smaller than 3%, the microcomputer 10 gradually decreases the duty of the PWM signal output to the integrating circuit 12 from 5% to 0% (arrow in the figure). (See dotted line). Thereby, the light source 4 is controlled so as not to be turned off suddenly. In FIG. 3, for the sake of convenience, the broken line is drawn so as to decrease to the left as the duty of the dimming signal becomes smaller than 3%. However, the microcomputer 10 actually outputs the PWM output to the integrating circuit 12. The signal duty is gradually decreased (fade out) at a constant decrease rate within a predetermined time from 5% to 0%.

  In the above example, the duty of the PWM signal output to the integrating circuit 12 is calculated as a coefficient of Imax on the right side of the equation (1) or (3). However, the integrating circuit 12 depends on the duty D1 of the dimming signal. The duty of the PWM signal to be output may be calculated in advance and stored in a table. Hereinafter, a case where the current supplied to the light source 4 is adjusted to be small or large according to the duty of the dimming signal will be described as an example. Further, the duty of the PWM signal to be output to the integrating circuit 12 is set as the duty to be adjusted or the target duty, and these duties are equal to the magnitude of the current to be reached by the adjustment or the magnitude of the target current. It will be explained as being.

  FIG. 4 is an explanatory diagram showing a configuration example of the dimming table 111 for converting the duty of the dimming signal. The dimming table 111 stores 100 data corresponding to the duty of 100 dimming signals from 1% to 100%. These data are obtained by substituting D1 ′ obtained by substituting the duty D1 of the dimming signal into the equation (2) into the equation (1), and expressing the calculated 1−D1 ′ value as a% value. They are arranged in the order of% values. That is, for the points on the solid line in FIG. 3, the% value of the value on the horizontal axis is converted to the% value of the value on the vertical axis. However, when it exceeds 97%, it is not stored in the table because it fades out. For example, when the detected duty D1 is 0.16 (16%), by reading 88, which is the 16th data from the head of the dimming table 111, the magnitude of the current to be reached by adjustment or the target Is determined to be 88%.

  Next, fade-in and fade-out will be described. FIG. 5 is a graph showing temporal changes in the current supplied to the light source 4 during fade-in and fade-out. The horizontal axis in the figure represents time (t), and the vertical axis represents the current supplied to the light source 4. A solid line and a broken line indicate a change in current in the case of fade-in, and a one-dot chain line indicates a change in current in the case of fade-out. Both fade-in and fade-out are assumed to start at time t0.

  When fading in to the target current I1 as indicated by the solid line, the current supplied to the light source 4 gradually increases linearly from 0 to I1 between times t0 and t1. Further, when fade-in is performed to the target current I2 as indicated by a broken line, the current supplied to the light source 4 gradually increases linearly from 0 to I2 from time t0 to t1. On the other hand, when fading out from the state in which the current I3 is supplied to the light source 4 as indicated by the alternate long and short dash line, the current supplied to the light source 4 gradually decreases linearly from I3 to 0 from time t0 to t1. To do. However, the increase and decrease in current in each case of fade-in and fade-out is not limited to a linear one.

  When the fade-in is actually performed toward the target current or the fade-out is performed toward the current 0, the current supplied to the light source 4 is increased or decreased stepwise multiple times. Hereinafter, the time required for fade-in and fade-out is referred to as FI time and FO time. In this embodiment, the FI time and the FO time are set in advance to a time in seconds of 1 second or more, and every time the FI time or the FO time is equally divided (hereinafter referred to as one step time), The current supplied to the light source 4 is increased or decreased stepwise.

  Since the increase / decrease of the current performed during the FI time or the FO time is executed up to 100 times, a table can be used to reduce the amount of calculation each time. FIG. 6 is an explanatory diagram showing a configuration example of the FIFO table 112 that stores the ratio of current to be increased or decreased. The FIFO table 112 stores 100 values indicating the ratio from 0.01 (1%) to 1.00 (100%) in ascending order. The value of the current at each step is calculated by multiplying the value sequentially read from the FIFO table 112 every time of one step by the target current that is finally increased or decreased. By using such a table, the current supplied to the light source 4 can be reduced smoothly so as to be drawn with a downward convex curve with respect to time, or can be increased smoothly so as to be drawn with an upward convex curve. Can also be easily done.

  For example, when performing fade-in, the current magnitude of the j-th step is calculated by multiplying the target current magnitude by the j-th (j is a natural number of 100 or less) stored content of the FIFO table 112. . Also, when fading out, the magnitude of the current at the j-th step is calculated by multiplying the magnitude of the current immediately before the fading out by the (100-j) th stored content of the FIFO table 112.

  By the way, when the duty of the dimming signal changes more than a certain value during the fade-in, and when the duty of the dimming signal becomes 90% or less during the fade-out, the fade-in and fade-out It is preferable to perform the dimming according to the duty of the new dimming signal. FIG. 7 is a graph showing the time change of the current supplied to the light source 4 when the fade-in is interrupted. The horizontal axis in the figure represents time (t), and the vertical axis represents the current supplied to the light source 4.

  A solid line and a straight line indicated by a broken line obtained by extending the solid line indicate a change in current when fade-in starts at time t0 toward the target current I1 and ends at time t1. When the fade-in is interrupted when the current is I4 at time t3, the current supplied to the light source 4 is a new target between time t3 and t5 and t6, as indicated by the solid line and the alternate long and short dash line, respectively. Toward the currents I5 and I6, the absolute value of the rate of time change of the current gradually decreases. In this case, since the difference between the currents I4 and I5 is larger than the difference between the currents I4 and I6, the time t5 is later than the time t6.

Since the same applies to the case where the fade-out is interrupted and the current supplied to the light source 4 is made asymptotic toward the new target current, illustration is omitted here. The current change after the fade-in and fade-out is interrupted may change along a curve expressed based on, for example, a power function f (t) = at ^b (a and c are real numbers). .

  FIG. 8 is a graph showing an example of a change curve of the current supplied to the light source 4 after the fade-in / fade-out is interrupted. The horizontal axis of the figure represents time (t), and the unit is ms. The vertical axis represents the magnitude of current, and the unit is (%). The solid line in the figure shows the change characteristics when the current magnitude is determined according to a specific procedure. Also, the broken line indicates the change characteristic of the current magnitude expressed by Equation (5) using the following power function. In either case, the fade-in is interrupted when the current magnitude is 10%, and the change characteristic is shown when the current magnitude gradually approaches the target magnitude of 100%.

g (t) = − 0.37 {(90−t) / 10} ^2.5 +100 (5)

  The specific procedure is to determine the current magnitude (%) to be added to the current magnitude in accordance with the difference between the current magnitude and the target current magnitude. Here, 20 is added when the difference is 35 or more, 10 is added when it is 15 or more and less than 35, 5 is added when it is 6 or more and less than 15, and 3 is added when it is 3 or more and less than 6. When it is less than 3, 1 is added. When the target current magnitude is smaller than the current magnitude when the fade-in / fade-out is interrupted, the addition may be replaced with the subtraction in the above procedure. The magnitude of the current determined in this way agrees with the magnitude of the current calculated by the above equation (5) with high accuracy.

  Below the graph shown in FIG. 8, the magnitudes of currents after the elapse of each time are shown in comparison with the cases indicated by solid lines and broken lines. When the elapsed time after the fade-in interruption is 0, 10, 20, 30, 40, 50, 60, 70, 80, and 90 (ms), the magnitude of the current indicated by the solid line is 10, 30, 50 , 70, 80, 90, 95, 98, 99, 100 (%), the magnitude of the current indicated by the broken line is 10.1, 33.0, 52.0, 67.4, 79. 3, 88.2, 94.2, 97.9, 99.6, and 100 (%).

  In order to determine or calculate the magnitude of the current after interruption of fade-in and fade-out actually, it may be determined according to the above procedure, or may be calculated by appropriately modifying equation (5). Also, representative change characteristics as shown in FIG. 8 are stored in a table in advance, and a part of the representative change characteristics is reproduced by referring to an appropriate part of the table according to the difference. It may be calculated as follows. For example, when the difference between the current current magnitude and the target current magnitude is 30%, a point of 30 ms on the horizontal axis corresponding to 70% obtained by subtracting 30% from 100% on the vertical axis in FIG. The table portion corresponding to the change characteristic on the right side may be referred to.

  Below, operation | movement of the microcomputer 10 mentioned above is demonstrated using the flowchart which shows it. FIG. 9 is a flowchart showing a procedure of initialization processing by the CPU 100. FIG. 10 is a flowchart illustrating a processing procedure of the CPU 100 that executes fade-in, dimming, and fade-out. FIG. 11 is a flowchart showing a procedure of fixed cycle processing by the CPU 100 during fade-in and fade-out. FIG. 12 is a flowchart showing the processing procedure of the CPU 100 after the fade-in and fade-out are interrupted.

  The process shown in FIG. 9 is started at the time of reset due to power-on or the like. The process shown in FIG. 10 is started first after the end of the initialization process shown in FIG. 9, and the second and subsequent processes are started in a timely manner as a process starting from step S27. The process shown in FIG. 11 is started every 10 ms counted by the timer 140 during fade-in and fade-out. However, the activation cycle is not limited to 10 ms. The process shown in FIG. 12 is started during the process shown in FIG. The “FIFO time” in the figure is preset in the RAM 120 or the ROM 110. “I”, “j”, “FIFO flag”, “current current magnitude”, “current magnitude to be increased / decreased”, and “current current magnitude” are stored in the RAM 120. In particular, the “light control duty” is stored in the storage unit 121.

  When the processing of FIG. 9 is activated, the CPU 100 reads the FIFO time from the RAM 120 or the ROM 110 (S11), and divides the FIFO time by 100 to calculate the time for one step of fade-in and fade-out (FIFO). (S12). The divisor here is not limited to 100. Next, the CPU 100 calculates the number N of processes per step by dividing the time of one step of the FIFO by 10 ms (S13). For example, when the FI time and the FO time are 3 seconds, N is 3. Thereafter, the CPU 100 initializes i to N (S14), initializes j to 1 (S15), and ends the process of FIG.

  Subsequently, when the process of FIG. 10 is started, the CPU 100 takes in the dimming signal from the dimmer 3 and detects the duty of the dimming signal, that is, the dimming duty (S21), and the detected dimming duty is 90. It is determined whether it is less than or equal to% (S22). If it is not less than 90% (S22: NO), it waits until it becomes 90% or less. When the light control duty is 90% or less (S22: YES), the CPU 100 stores the detected light control duty in the storage unit 121 (S23).

  Thereafter, the CPU 100 refers to the dimming table 111 based on the dimming duty detected and stored, and determines the magnitude of the current to be increased or decreased by reading the target current magnitude (S24). Next, the CPU 100 sets the FIFO flag to 1 (S25) and stores that it is fading in. In this case, the periodic activation of the process shown in FIG. 11 is started. Thereafter, the CPU 100 determines whether or not the FIFO flag is 0 (S26). Thus, it is determined whether or not the fade-in and the fade-in interruption process are completed and the FIFO flag is cleared to 0 in the process shown in FIG. When the FIFO flag is not 0 (S26: NO), the CPU 100 waits until the FIFO flag becomes 0.

  When the FIFO flag is 0 (S26: YES), that is, when the fade-in and the fade-in interruption process are completed, the CPU 100 detects the duty by taking the dimming signal from the dimmer 3 (S27), and detects it. With respect to the dimming duty, it is determined whether or not there is a change to the dimming duty stored in the storage unit 121 (S28). If there is no change (S28: NO), the process proceeds to step S27.

  In the determination of whether or not there is a change in step S28, for example, it is preferable to determine whether or not the difference in duty is 1% or more so that a difference within a certain range is not treated as a change. Further, while the duty stored in the storage unit 121 is 97% or more, it is preferable to determine that there is no change until the detected dimming duty is less than 97%. This prevents the fade-out from starting again when the process starting from S27 in FIG. 10 is started after the end of the fade-out.

  When there is a change in the dimming duty (S28: YES), the CPU 100 stores the detected dimming duty in the storage unit 121 (S29), and determines whether the dimming duty is 97% or more ( S30). When it is not 97% or more (S30: NO), the CPU 100 refers to the dimming table 111 based on the detected dimming duty to determine the magnitude of the current to be adjusted (S31). Next, the CPU 100 stores the determined magnitude of the current as the current magnitude (S32), and sets the duty for the integrating circuit 12 according to the magnitude of the current (S33: to the dimming unit). Corresponding), the process proceeds to step S27.

  When the dimming duty is 97% or more in step S30 (S30: YES), that is, when the state to be faded out is reached, the CPU 100 increases or decreases the current level stored previously. (S34). Next, the CPU 100 sets the FIFO flag to 2 (S35) and stores that it is fading out. In this case, the periodic activation of the process shown in FIG. 11 is started. Thereafter, the CPU 100 determines whether or not the FIFO flag is 0 (S36). Thus, it is determined whether or not the fade-out and the fade-out interruption process are completed and the FIFO flag is cleared to 0 in the process shown in FIG. 11 or FIG.

  When the FIFO flag is not 0 (S36: NO), the CPU 100 waits until the FIFO flag becomes 0. When the FIFO flag is 0 (S36: YES), that is, when the fade-out and the fade-out interruption process are finished, the CPU 100 finishes the process of FIG. Thereafter, as described above, when the process starting from step S27 is started, the CPU 100 resumes the process of dimming the light source 4 by detecting the duty of the dimming signal from the dimmer 3.

  In the process of FIG. 11 activated every 10 ms, the CPU 100 determines whether or not the FIFO flag is 0 (S41). If it is 0 (S41: NO), the CPU 100 does not execute any special process. End the process. That is, when the FIFO flag is 0, the fade-in and fade-out operations are prohibited. When the FIFO flag is not 0 (S41: YES), that is, when the fade-in or fade-out is being performed, the CPU 100 decrements i by 1 (S42). Next, the CPU 100 determines whether i is 0 (S43). If it is not 0 (S43: NO), the CPU 100 ends the processing of FIG. 11 without performing any further processing.

  If i is 0 (S43: YES), that is, if it is the Nth process, the CPU 100 initializes i to N (S44), and then determines whether or not the FIFO flag is 1 (S45). ). When the FIFO flag is 1 (S45: YES), that is, when the fade-in is in progress, the CPU 100 reads the ratio that is the jth storage content in the FIFO table 112 (S46). On the other hand, when the FIFO flag is not 1 (S45: NO), that is, when fading out is in progress, the CPU 100 reads the ratio that is the (100-j) th storage content in the FIFO table 112 (S47).

  When the process of step S46 or S47 is completed, the CPU 100 multiplies the magnitude of the current stored in the RAM 120 to be increased or decreased and the read ratio, and sets the multiplication result as the magnitude of the j-th current (S48). . Next, the CPU 100 stores the calculated current magnitude of the j-th step as the current current magnitude (S49), and sets the duty for the integrating circuit 12 according to the current magnitude (S50: gradual increase). Part and gradually decreasing part). If the calculated current magnitude is the same as the current magnitude before update in units of 1%, the process of step S50 may be skipped.

  Thereafter, the CPU 100 receives the dimming signal from the dimmer 3 and detects the duty (S51), determines whether or not the FIFO flag is 1 (S52), and classifies the cases. When the FIFO flag is 1 and the fade-in is in progress (S52: YES), the CPU 100 uses the absolute value of the value obtained by subtracting the duty stored in the storage unit 121 from the detected dimming duty as the change in the dimming duty. Calculate (S53). Next, the CPU 100 determines whether or not the calculated change amount is, for example, 1% (corresponding to a predetermined value) or more (S54), and if it is 1% or more (S54: YES), the fade-in is interrupted. In order to do so, the process proceeds to step S61 described below. In addition, the percentage used for determination of a change part by step S54 is not limited to 1%.

  If the calculated change is not 1% or more (S54: NO), the CPU 100 increments j by 1 (S56), and determines whether j is 101 (S56). When j is not 101 (S56: NO), the CPU 100 once ends the process of FIG. When j is 101 (S56: YES), that is, when the fade-in or fade-out is to be ended, the CPU 100 clears the FIFO flag to 0 (S57: corresponding to the prohibition unit and the second prohibition unit). In this case, the periodic activation of the process shown in FIG. 11 may be stopped. Thereafter, the CPU 100 initializes j to N (S58), initializes j to 1 (S59), and ends the process of FIG.

  On the other hand, if it is determined in step S52 that the FIFO flag is not 1 (fade out) (S52: NO), the CPU 100 determines whether or not the detected dimming duty is 90% or less (S60). If the dimming duty is not 90% or less (S60: NO), the process proceeds to step S55 in order to continue the fade-out and execute the process common to the fade-in. On the other hand, when the dimming duty is 90% or less (S60: NO), the CPU 100 stores the detected dimming duty in the storage unit 121 (S61), and the FIFO shown in FIG. 12 is used to interrupt the fade-out. The interruption process is activated (S62), and the process proceeds to step S57.

  In the process of FIG. 11 described above, the duty of the dimming signal is detected every N × 10 ms, but the duty of the dimming signal may be detected every 10 ms.

  When the process shown in FIG. 12 is started in step S62, the CPU 100 determines a new target current magnitude with reference to the dimming table 111 based on the dimming duty stored in the storage unit 121 (S71). ). Next, the CPU 100 calculates a difference in current magnitude with a sign by subtracting the current magnitude stored in the RAM 120 from the determined new target current magnitude (S72), and calculates the calculated difference. Is determined to be 0 (S73). When the difference is 0 (S73: YES), the CPU 100 ends the process of FIG.

  If the difference is not 0 in step S73 (D73: NO), the CPU 100 determines the magnitude of the current to be added / subtracted according to the magnitude of the difference (S74), and stores the determined magnitude in the RAM 120. By adding / subtracting to / from the stored current magnitude, the current magnitude is stored to be updated (S75). In this case, when the difference is positive, the determined current magnitude is added, and when the difference is negative, the determined current magnitude is subtracted. The addition / subtraction here is based on the method described with reference to FIG. Next, the CPU 100 sets a duty for the integrating circuit 12 according to the updated current magnitude (S76: corresponding to an asymptotic part) and waits for 10 ms (corresponding to a predetermined time) (S77), and then proceeds to step S72. Move processing. Note that the time for waiting in step S77 is not limited to 10 ms.

  Each of the flowcharts described above describes the case where the current supplied to the light source 4 is adjusted to be small or large depending on the duty of the dimming signal. When the current supplied to 4 is adjusted to be large or small, a part of the processing may be rewritten. Specifically, in step S22 of FIG. 10, it is determined whether the dimming duty is 5% or more, and in step S30, it is determined whether the dimming duty is 3% or less. Moreover, what is necessary is just to determine whether the light control duty is 5% or more in step S60 of FIG.

  In the decision branches of steps S22, S30, S54, S60, etc. in the above-described flowcharts, “≧” (greater than equal) and “≦” (less than equal) with equal signs are used. Some “>” (greater than) and “<” (less than) may be used.

  As described above, according to the present embodiment, a dimming signal that is a PWM signal is acquired from the dimmer 3, and a current based on the acquired dimming signal is supplied to the light source 4 to be lit. When the duty of the dimming signal from the dimmer 3 is in the range of 5% to 90%, the current supplied to the light source 4 according to the change (ie, increase and decrease) of the duty of the dimming signal Is adjusted to a small or large (that is, decreases and increases), or a second structure that adjusts the current supplied to the light source 4 to a small or large (that is, increases and decreases) is adopted. In the first configuration, it is determined whether the duty of the dimming signal acquired before starting the dimming is smaller than 90%. In the second configuration, the duty of the dimming signal acquired before starting the dimming is 5 It is judged whether it is larger than%. When the determination is established, the determined dimming duty is stored in the storage unit 121, and the current supplied to the light source 4 is gradually increased toward the target current corresponding to the dimming duty. When the duty of the dimming signal newly acquired while gradually increasing the current differs from the duty stored in the storage unit 121 by 1% or more, the increase in the current supplied to the light source 4 is stopped and newly acquired. The current supplied to the light source 4 is made asymptotic toward a new target current corresponding to the duty of the dimming signal. Accordingly, it is possible to perform a light adjustment operation with the light adjuster 3 even during fade-in.

  In addition, according to the present embodiment, each time the current supplied to the light source 4 is adjusted according to the duty of the dimming signal acquired from the dimmer 3, the duty of the dimming signal acquired is 90% in the first configuration. It is determined whether or not it is greater than 97%, and in the second configuration, it is determined whether or not the duty of the acquired dimming signal is 3% or less, which is less than 5%. When the determination is established, the current supplied to the light source 4 is gradually decreased toward the target current corresponding to the determined duty. When the duty of the dimming signal newly acquired while gradually decreasing the current is smaller than 90% in the first configuration or larger than 5% in the second configuration, the current supplied to the light source 4 is gradually decreased. The current supplied to the light source 4 is made asymptotic toward a new target current corresponding to the duty of the dimming signal newly acquired while the current is stopped and gradually reduced. Accordingly, it is possible to perform a light adjustment operation by the light adjuster 3 even during fading out.

  Furthermore, according to the present embodiment, the absolute value of the amount of change per unit time, that is, the absolute value of the slope of the current change is gradually reduced with respect to the current supplied to the light source 4 so as to gradually approach the new target current. To be. Thereby, it becomes possible to approach the target current more quickly and smoothly than when the current supplied to the light source 4 is linearly changed.

  Furthermore, according to the present embodiment, when the current supplied to the light source 4 is changed every 10 ms to make the new target asymptotic, the difference between the new target current and the current supplied to the light source 4 is As the magnitude is less than 3%, 3% or more, 6% or more, 15% or more, and 35% or more, the amount of change in current every 10 ms is 1%, 3%, 5%, 10%, and 20 Increase it to%. Thereby, it is possible to simplify the calculation when the current supplied to the light source 4 is asymptotic to a new target current.

  Furthermore, according to the present embodiment, the magnitude of the current supplied to the light source 4 is stored in the dimming table 111 in association with the duty of the dimming signal, and is based on the newly acquired duty of the dimming signal. By referring to the dimming table 111, a new target current is determined. Thus, with respect to the current supplied to the light source 4, the current to be adjusted in the case of normal dimming, the target current in the case of performing fade-in, and the new target current in the case where the fade-in and fade-out are interrupted Can be easily calculated.

1 lighting device 10 microcomputer 100 CPU
110 ROM
111 Dimming table 112 FIFO table 120 RAM
121 storage unit 130 I / O
140 Timer 11, 14 Photocoupler 12 Integration Circuit 13 Operational Amplifier 15 Control IC
16 DC / DC converter 17 Resistor 20 PFC circuit 3 Dimmer 4 Light source 5 AC power supply

Claims (5)

In a lighting device that obtains a dimming signal indicating the degree of adjustment of the light amount of the light source from the outside in time series, and supplies a current based on the obtained dimming signal to the light source to light it,
The dimming signal is a PWM signal;
When the duty of the acquired dimming signal is larger than the first threshold and smaller than the second threshold larger than the first threshold, the current supplied to the light source is made small (or large) according to the magnitude of the duty. A dimmer to be adjusted,
When the duty of the dimming signal acquired before the dimming unit starts adjustment is smaller than the second threshold (or larger than the first threshold), a storage unit that stores the acquired duty of the dimming signal;
A gradual increase unit that gradually increases a current supplied to the light source toward a target current to be adjusted by the dimming unit according to the duty stored in the storage unit;
When the duty of the dimming signal newly acquired while the gradually increasing part gradually increases the current is different from the duty stored in the storage part by a predetermined value or more, a prohibiting part for prohibiting the operation of the gradually increasing part,
Asymptotics for asymptotically supplying the current supplied to the light source toward a new target current to be adjusted by the dimming unit according to the duty of the newly acquired dimming signal when the prohibiting unit prohibits the operation A lighting device comprising: and a lighting device. Each time the light control unit adjusts the current, if the duty of the acquired light control signal is greater than (or less than) the third threshold value (or less than the first threshold value), the light control unit A gradual decrease unit that inhibits the operation of, and gradually decreases the current supplied to the light source;
When the duty of the dimming signal newly acquired while the gradual decrease unit is gradually decreasing the current is smaller than the second threshold (or larger than the first threshold), the operation of the gradual decrease unit is prohibited. And a prohibited part of
The asymptotic part, when the second prohibiting part prohibits the operation, toward the new target current to be adjusted by the dimming part according to the duty of the further newly obtained dimming signal, The lighting device according to claim 1, wherein the current supplied to the light source is made asymptotic.   The lighting device according to claim 1, wherein the asymptotic part gradually decreases an absolute value of a time change rate of a current supplied to the light source. The asymptotic part is
The current supplied to the light source is changed every predetermined time,
The amount of change in current to be changed at each predetermined time is adjusted to be large or small according to the difference between the new target current and the current supplied to the light source. The lighting device described in 1. A table for further storing the duty of the dimming signal and the magnitude of the current adjusted by the dimming unit according to the duty;
The asymptotic unit uses the magnitude of the current stored in the table in association with the duty of the newly acquired dimming signal as the new target current. The lighting device according to any one of the above.

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