JPS61104586A - Dimmer system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a dimming method for controlling the phase angle of a lighting lamp, and more specifically, a method for controlling the phase angle so that the rate of change in brightness of the lighting lamp is uniform. It is related to a dimming method that makes it possible to adjust the brightness of the evening.

BACKGROUND ART In a typical prior art, a processing circuit includes a key manual means, a random access memory (hereinafter referred to as RAM), and a power synchronization signal generator that generates a power synchronization signal in synchronization with an AC power supply that energizes a lighting lamp. The processing circuit provides dimming data to the phase control element of the dimming drive unit in synchronization with the power supply synchronization signal, thereby changing the energization angle of the commercial AC power supply that energizes the lighting lamp by half a cycle. It is configured to be controlled separately.

In such a light control device, a cross-fade operation is generally performed as a method of lighting technology. Here, cross-fade refers to a function in which when moving from one dimming scene to another, the brightness does not change instantaneously, but changes smoothly over a certain period of time, for example, 1 second or 3 seconds. Conventional dimming devices require half a cycle of the frequency of the commercial AC power supply to shift from the current brightness to the next brightness when input that the scene has changed through such key manual means. Add dimming data every time you count
The first equation was used to calculate whether it should be 1 or -1.

20t Y-X (1) where L is the cross-fade time (seconds), X is the brightness of circuit 1 in the current scene, and Y is the brightness of circuit 1 in the next scene. Further, if the frequency of the commercial AC power source is 60 Hz, there are 120 half cycles in 1 second, and therefore 120 t in t seconds.

FIG. 5 is a flowchart showing the procedure of dimming control in the prior art. In step n1, it is determined whether the power synchronization signal has changed from low to high, and if so, the process moves to step n2, where the dimming data is inverted and output to RAW. Thereafter, the process moves to step n3, where it is determined whether or not the cross is in progress. If the cross is not in progress, the process moves to step n4, where the contents of the key manual means are read. Then, the process moves to step n5, where it is determined whether or not the scene change key has been pressed, and if the scene change instruction has been pressed, the process moves to step n6, where Y-X is changed to N.
, N' and change the dimming data by ±1 every half cycle.
ask whether Then, proceed to step n7 and Y-1-
It is determined whether X > O, that is, whether the brightness of the current scene is greater than the brightness of the next scene, and if so, the process moves to step n8 and goes to step 7.
Let the lag Z be the logic rl(H)J. Also step n8
If y−x<o in step n9
, and let the 7-lag Z be the logic IF F (H)J. Note that if there is no scene change in step n5, the process moves to step nlo and other processing is performed.

From step n8 or step n9, the process goes back to step 81 to step n3, and if the cross is in progress at step n3, the process goes to step nil, where N is 1.
Subtracted. That is, a counter indicating whether the dimming data is ±1 in a half cycle is decremented by -1. Then, the process moves to step ni2, where it is determined whether or not N' is O. If N' is 0, the process moves to step n13, where the value of 7 lags Z is added to the current dimming data X. In addition, when the scene change is an increase, 7 lag Z is logic 11(H)J, so
If the logic rl(H)J is added to the current dimming data
Add F (H)J to the current dimming data X. In other words, this results in the same state as when -1 is subtracted. Then, move to step nL4, and since N'' became O, change to N゛.
Substitute. Then, the process returns to step 01 to step n3, and the series of operations from step n11 to step n14 is repeated. When N' is O in step nl 2 , the process moves from step n12 to step n2, and the dimming data obtained by adding ±1 to the current dimming data X is output.

Note that in the above-mentioned prior art, a single circuit is described for the sake of simplification of explanation.

In such conventional dimming methods, the voltage waveform of the commercial AC power supply is a sine wave as shown in Figure 6, so the dimming characteristic of the lighting lamp is an S-shaped curve as shown in Figure 7. The change is slow near the dimming level of 10% and 100%, and the change is rapid in the middle, so the cross-fade is not performed smoothly.

Purpose An object of the present invention is to provide a dimming system that controls the brightness change rate of illumination lights to be uniform when a crossfade operation is performed so that a crossfade can be performed smoothly. The purpose is to provide a method.

Embodiment FIG. 1 is a block diagram showing the electrical configuration of an embodiment of a light control device according to the present invention. Key human power means 2 for CPUI
is connected, and by operating this key manual means 2, the CPU 1 creates dimming data for each of the illumination lights L1 to Ln. This dimming data will be 0(H) to 7F(H) assuming 128 steps of digital dimming. Note that (H) here indicates a hexadecimal number. Light control data 0 (H) corresponds to a brightness of 0%, and 7F (H) corresponds to a brightness of 1°0%. Although the inside of cptz is as described above, the dimming data from the CPU is output with the lower 7 bits inverted due to the latter stage. For example, the dimming data inside the CPUI is 0 (
H), outputs 7F(H). Also CPU
When the internal dimming data of I is 7F(H), the output dimming data is 0(H).

A power synchronization signal generation circuit 3 is also connected to C and PUI, and when the voltage waveform of the AC power supply 4 of the lighting lamps L1 to Ln is as shown in FIG. 2 (1), the power synchronization signal generation circuit 3
derives the pulse signal shown in FIG. 2(2) to the CPUI. The dimming data from the CPU is sent to the line when the power synchronization signal is high! 1 to the switch 5, and when the power synchronization signal is high, the data from the CPUI is sent to the RA
input to M6, and when the power synchronization signal is low, RAM6
The data is output to the digital-to-analog converter 7.

Another switch 18 inputs the address from the CPUI via the liner 2 when the power synchronization signal is 2)A, and when the power synchronization signal is low, the address generator 9
Input the address from to RAM 6. This address generator 9 is reset when the power synchronization signal is high, and when it is low, it generates addresses for the number of circuits. Therefore, the second
As shown in Figure (2), the dimming data is written to the RAM 6 when the power synchronization signal is high, and the dimming data written to the RAM 6 when the power synchronization signal is low is transferred to the digital-to-analog converter 7. is called. The digital-to-analog converter 7 converts the 8-bit input into DCO to 10 volts, as shown in FIG. 2(3), and outputs it to the analog multiplexer 1o.

This analog multiplexer 10 outputs the input to each circuit according to the address from the address generator 9, as shown in FIG. 2 (4).

This output is charged into a capacitor 12 via a buffer 11 to hold the voltage, and is also applied to one terminal of a comparator 13. The other terminal of the comparator 13 is given the output of the charging circuit 14 which is reset by the high level of the power synchronization signal as shown in FIG. 2 (5). In the comparator 13, the output from the buffer 11 and the charging circuit 1
By comparing the outputs of the triacs 4 and 4, a pulse signal as shown in FIG. The triac 15 includes lighting lights L1 to Ln and a commercial AC power source 4.
are connected in series, and the conduction angle is controlled by this triac 15 as shown in FIG. 2 (7).

FIG. 3 is a diagram for explaining the outline of the dimming method of the present invention. In FIG. 3, when the horizontal axis is the dimming data (phase angle) and the vertical axis is the output voltage, the dimming characteristics of the illumination lamps L1 to Ln are shown by line No. 3.

Considering 128 steps of digital dimming, the dimming data ranges from 0(H) to 7F(H). This dimming data 0 (H) to 7F (H) is divided into 32 sections PI.

P2. Divide into P3. In section P1, dimming data 0 (H)
〜2A(H) is included, and 2B〜55 is included in section P2.
(H) is included, and in section P3, 56 (H) to 7
Contains F(H). Here, the current dimming data is A
, the next scene's dimming data is B, the cross-fade time is t1, the number of change steps of the dimming data included in section P1 is Hl,
Assuming that the number of change steps of the dimming data included in section P2 is H2, the number of change steps of the dimming data included in section P3 is H3, and that the dimming characteristics 3 of each section P1 to P3 are linear, then section P1 If the crossing time at is tl, then the second equation holds true.

Therefore, the third equation is derived, and the cross time t1 is the fourth
It is shown by the formula.

15(l11+113)+70x 112:1511
1=t:tl...(3) Similarly, the cross time in section P2 is set to t2, and section P3
Letting the crossing time of t3 be t3, it is expressed by the fifth and sixth equations.

For example, if the current dimming data a is 16 (H) and the next scene's dimming data b is 5F (H), and if we consider the time when X braking is performed in 3 seconds, then Equations 4 to 6 can be used. The cross opening t1 is expressed by the seventh equation, the crossing time t is expressed by the eighth equation, and the crossing time t3 is expressed by the ninth equation.

Therefore, from point A to 2a(H) in 0.26 seconds, from 2b(H) to 55(H) in 2.62 seconds, and from 56(I() to 5F(H) in 0.12 seconds) By doing this, the brightness of the lighting lights will cross-fade smoothly.

FIG. 4 is a flowchart showing the control operation of the dimming method according to the present invention. A more specific procedure for dimming control will be described in detail using FIG. 4. In step A1, it is determined whether or not there is a rising power of the power synchronization signal, and if there is a rising input, the process moves to step A2, and the CP
Light control data is output from the UI. Next, the process moves to step A3, where it is determined whether or not the number of up/down cycles N is 0. If not, it is assumed that a cross operation has been performed, and the process moves to step C4 for cross processing.

If the number N of up/down cycles is 0 in step A3, the process moves to step A4, and the key data repeated by the input means 2 is read. After that, the process moves to step A5, where it is determined whether or not a scene change is instructed.
If a scene change is instructed, the process moves to step 80 and cross value setting processing is performed. Step C4~
Step A13 or Step C4 to Step B13
Now, 1, 5 (H1+H3)+70H2, which is the denominator of the above-mentioned formula 6 to calculate the cross time for each section P1 to P3.
is determined and substituted into work area F5. Then, enter the number of interval changes for the higher dimming level in H3, the number of interval changes for the lower dimming level in Hl, and the number of interval changes for the intermediate dimming level in H2. . After these procedures have been carried out, in step A14, the 7 lag F1 indicating dimming up or down is set to logic rl(H)J
, or the logic [FF (H)J.

Here, when the 7-lag F1 is the logic rl(H)J, it indicates up, and the logic IF F(H)J is ~
11- When it appears, it indicates that it is down. When the dimming data is updated in step A14, step A15 to step A2
The process moves to Step 3 and processing is performed, and when the system is down, the process moves to Step 815 to Step B23 and processing is performed. In steps A1.5 to A23, the number of up and down cycles for each section is entered into the change stage numbers H1 to H3 of the sections P1 to P3, respectively. Similarly, in step 815 to step B23, the number of change stages H1
~ Enter the number of up and down cycles for each section in H3.

Then, through step A15 to step A23 or step 815 to step B23, step A1 to step B23 is performed again.
The process moves to steps C4 to C13 via step A3. In steps C4 to C13, the work area N' whose number of up/down cycles is N is subtracted by 1 every half cycle, and when it becomes 0, the dimming data is increased or decreased. When the cross-fade for each section P1 to P3 is completed, the number of up/down cycles for that section is set to O from 1 to 3. When these processes are completed, the process returns to step A1 and the next rising edge of the power synchronization signal is input.

If there is no change in the scene in step A5, the process moves to steps C4 to D12, and each section P1
~P3 up/down cycle number Kl, 2. 3 in this order, and if it is not O, set the number of cycles to N as the number of up-down cycles. When all 3's in K1- are 0, other processing is performed as unrelated to the cross 7 aid.

Next, the dimming control method will be explained in detail in the following 12 cases depending on which of the sections P1 to P3 the current dimming data A and the dimming data B of the next scene are in.

(i) Current dimming data A and next scene dimming data B
is in section P1, and the next dimming data B is larger than the current dimming data A.

First, in step A1, it is determined whether or not there is a rising input of the power synchronization signal, and if there is a rising input, the process moves to step A2 and dimming data is output.

Next, the process moves to step A3, where it is determined whether the number N of up-down cycles is O or not. If it is not 0, it is determined that a cross is being performed, and the process moves to step C4. If the number N of up-down cycles is 0, it is assumed that no cross-fade operation has been performed, and the process moves to step A4. In step A4, the key data instructed by the key operator Fi2 is read. After that, the process moves to step A5, and it is determined whether or not a scene change is instructed by the key data. If so, the process moves from step A5 to step A6, and the current dimming data A is changed to the next scene. It is determined whether or not it is larger than the dimming data B, that is, whether an operation to decrease the dimming level has been performed, and if an operation to increase the dimming level has been performed, the process moves to step B7. In step B7, the next scene's light control data B is entered into X, and the current light control data A is entered into Y. Then, the 7 lag F1 is set to logic rl(H)J indicating that it is the up time. Next, moving to A8, it is determined whether or not X-56(H)>0. Since the next scene's dimming data B, therefore X, is in the section P1, the process moves from step 88 to step B8. In step B8, the number of change stages H3 included in section P3 is set to O. Next, the process moves to step B9, and it is determined whether or not X-2A(H)>0. Light control data B Therefore, X is
Since it is in section P1, X-2A(H)>0, and therefore the process moves from step B9 to step B12. In step 12, the number of change steps H2 included in section P2 is set to O, and X-Y is entered as the number of change steps H1 included in section P1.

After that, the process moves to step A13, and 1 is placed in the work area F5.
Substitute 5(H30H1)+70XH2. Note that here, the value obtained in the above step is substituted for F2°F 3 t' F 4 . After reaching step A13 in this way, the process further moves to step A14, where 7 lag F1 is set to logic "1 (
H)" is determined. Flag F1 is logical r
Since it is l(H)J, the process moves to step A15.

In step A15, it is determined whether the change stage number H1 of the section P1 is 0, and the change stage number H1 is set to 1. Then, the process moves to step A17, and it is determined whether or not the change stage number H2 is O. Since the change stage number H2 is 0 in the above-mentioned step B12, the process moves to step A22.
Let 2 be 0 for the number of up and down cycles in section P2.

Then, the process moves to step A19, and it is determined whether the number of change stages H3 is 0 or not. Since the change stage number H3 is determined to be O in step B8 described above, step A1
9, the process moves to step A23, and 3 is set to O for the number of up-down cycles in section P3.

Once the cross value setting process is completed in this way, the process goes through steps A1 to A3 again, and then moves to step C4 for cross processing.

In step C4, the work area N' of the total number N of up-down cycles of 1 to 3 is subtracted by 1 from the number of up-down cycles in each section P1 to P3. Then, the process moves to step C5, where it is determined whether N I is 0 or not.
If it is 0, the process moves to step A1 and step A2 again, and the dimming data added by +1 is output.

If N' is not O in step C5, the process moves to step C6, and the value of 7 lags F1 is added to the current dimming data A. Here, the value of 7 lag F1 is at the time of up, so +1
is added to A. Then, the process moves to step C7, and it is determined whether or not the cross processing is finished. If it is not finished, an up-down cycle N is entered into the work area N'. When the cross processing is completed in step C7, the process moves to step C9, and it is determined whether 1 is O for the number of up/down cycles in section P1.

If K1 is not 0, the process moves to step C10 and 1 is set to 0. As a result, the number of up and down cycles in the sections P1 to P3 becomes O from 1 to 3. Thereafter, the process returns to step A1 and waits for the next power synchronization signal.

(ii) The current dimming data A is in section P1, and the next scene's dimming data B is in section P2, and BA
In case of A.

In this case, as in the case (i) above, step A1
- The arithmetic processing up to step B9 is performed, and step B
At step B9, since the dimming data B and hence X are larger than 2A(H), the process moves from step B9 to step AIO. In step AIO, it is determined whether 2A(H) is greater than Y.

Since the current dimming data A, therefore Y, is in the interval P1, 2A(H)-Y>o, and therefore the step
Move from AIO to step A i 1. Step A
1.1, 2A(H)-Y is substituted for the change stage number H1, and 28(H) is substituted for Y. Then, the process moves to step A12, and X-Y is substituted for the change stage number H2. Then, the process moves to step A13, and the change stage numbers H1 to H3 obtained in the above steps are each 1.5 (H3+H1).
+70XH2 and this result is assigned to work area F.
given to 5. Thereafter, the process moves to steps A14 to A17 in the same manner as in (i) above, and since the number of change stages 82 is not 0, the process moves to step A18. 12 in step A18
0X70Xt sets F5 to 2 as the number of interval up/down cycles. Then, the process moves to step A19, and the change stage number H
Since 3 is 0, the process moves to step A23 and 3 is set to 0. In this way, the number of up and down cycles in the sections P1 to P3 is determined to be 1 to 3. As a result, the total number of up-down cycles N is obtained, and after that, step A1
- Step A3 and step C4 to step C13 are sequentially performed, and the same arithmetic processing as described above is performed to perform dimming control.

(iii) Current dimming data A is in section P1, and dimming data B for the next scene is in section P3, and B>
In case of A.

After going through step A1-step A6, step B7, and step A8, since the next scene's dimming data B, ie, X, is larger than 56 (H), the process moves to step A9. In step A9, the X-56 (H) is entered into the change stage number H3. Further, 56(H) is assumed to be X. Then step AI
15 (H3+H1)+ from O to step A13
The value of 70XH2 is found. Then step A14
→A15→A16→A17→A 1.8→A19→A2
The number of up and down cycles changes from 1 to 0.
The value of 3 is found for . Then step C as above
Moving on to steps 4 to C13, the same arithmetic processing as described above is performed.

(iv) When both dimming data A and B are in section P2 and are BAA.

After steps A1 to A6, step B7 and step A8, further step B8. B9 and step A
Moving on to iO. In step A10, since the current dimming data A, therefore Y, is greater than 2A(H), the process moves to step BIO. In step BIO, the number of change stages H1 is 0, and in step Bll, it is 56.
It is determined whether (H)-Y>0. Since the dimming data A is in the section P2, the dimming data A and therefore Y are smaller than 56 (H), and therefore the process moves from step Bll to step AIO. Thereafter, the process moves from step A12□ to step A13, and the work area F5 is obtained. Thereafter, the process moves to step A14→step A15→step A21, and 1 is set to 0 in the number of up and down cycles in section P1.

Then, moving from step A17 to step A1B,
120x70 to 2 for the number of up/down cycles in section P2
t F5 is assigned. Thereafter, the process moves from step A19 to step A23, where 3 is set to O for the number of up-down cycles in section P3. After the cross value setting process has been carried out in this manner, the process returns to step A1. Step A1
A series of operations from step A2 to step A3 to step C4 to step C'13 are repeated to perform dimming control.

Cv) 714 When light data A is in section Pl, dimming data B is in section P3, and BAA.

The flowchart in FIG. 4 in this case goes through the following steps. That is, step A1-
Step 86 → Step B7 → Step A8 ~ Step AIO → Go to step BI ~ Step Bll → Step A
12 to step A13. Then step A
13 to step A14 to step A15 → step A
21→Proceed to step A17 to step A20.

? Thus, by setting the number of up-down cycles K1 in section P1 to 0, the number of up-down cycles K-un total cycles N in section P2 is determined. After that, the process moves from step C4 to step C13 again through steps A1 to A3, and cross processing is performed.

(vi) When the current dimming data A and the next scene's dimming data B are both in section P3 and BAA.

In this case, proceed through the following steps. That is, step A1 to step A6 → step B7 → step 88
~Step AIO → Step B10 ~ Step Bll →
Step B13 -> Step A13 -> Step A14 - Step A15 -> Step A20 -> Step A21 -> Step A17 -> Step A22 -> Step A19 - Step A20 are passed through. As a result, the number of up/down cycles K1 in section opening P1 is set to O, the number of up/down cycles K2 in section P2 is set to 0, and the cross value is set in section P3. After that, the process moves to step C4 to step C13, and cross processing is performed in step 04 to step C13.

In (i) to (vi) above, the case where the dimming level is increased is explained, but below (vi)
In i) to (Zhao), the case where the dimming level reduction operation is performed will be explained.

(vii) Both dimming levels A and B are in section P1,
If A>B.

The process moves from steps A1 to A6 to step A7.

In step A7, the current light control data A is set to X, and the light control data B for the next scene is set to Y.

Also, let 7 lag F1 be logical rF (H) J.

Thereafter, the process sequentially moves to step A8→step 88 to step B9→step B12→step A13 to step A14. In step A14, 7 lag F1 is set to logic I
Since it is F F (H)J, the process moves to step B15.

After that, follow the steps below. That is,
Step B15→Step B21→Step B17→Step B22→Step B19→Step B20. After the cross value is set in this way, the process moves to steps A1 to A3 again, and then step C
4 #- et al. Cross processing to step C13 is performed.

Note that in step C6, the 7 lag F1 is set to the logic [FF
(H)J, so the current dimming data A has logic rF.
F(H)J is added. In other words, 1 is subtracted from the current dimming data A.

(vii) When the current dimming data A is in section P2 and the dimming data B of the next scene is in section P1.

In this case, the following steps are performed in sequence. That is, step A1 to step 86 → step A7 to step A8 → step 88 to step B9 → step A
IO ~ Step A14 → Step B15 → Step B2
1→Step 817 to step B20, the calculation process is performed sequentially. From then on, step A is the same as above.
1 to step A3, and step 0 as cross processing
4 to step C13.

(ix) When the current dimming data A is in section P3 and the dimming data B of the next scene is in section P1.

In this case, the following steps are performed in sequence. Steps A1 to A14→Steps B15 to B20 are followed, and steps A1 to A3 are sequentially followed in the same manner as described above, and further steps 04 to C1'3 are followed as cross processing.

(x)mN optical data A and B are both in section P2 and A
> In case of B.

In this case, follow the steps below. That is, step A1 ~ step AIO → step BIO ~
Step B11 → Step B13 → Step A13 to Step A14 → Step 815 to Step B17 → Step B22 → Step B19 → Step B20, and the same goes back to Step A1, and cross processing from Step A3 to Step C4 to Step C13 is performed. .

If the current dimming data A is in section P3 and the dimming data B of the next scene is in section P2, the following steps are followed in this case.

That is, step A1 - step AIO → step B
IO ~ Step Bll → Step A12 ~ Step A1
4 → Step 815 - Step B19 → Step B23
Following the route, the process moves again from step A1 to step A3 to step C4 to step C13 as cross processing.

(xi) When dimming data A and B are both in section P3 and A>B.

In this case, follow the steps below. That is, step A1 to step A8 → step B8 to step B9 → step AIO → step BIO to step Bll → step B13 → step 7''A13 to A14
→ Step B15 → Step B21 → Step 817~
Follow step B19 → step B23. Then, after going through steps A1 to A3 again, the process moves to steps 04 to C and 13 as a cross process, and arithmetic processing is performed.

In this way, regardless of whether the current dimming data A and the next scene's dimming data B are in any of the sections P1 to P3, the rate of change in the brightness of the illumination light is made uniform, resulting in smooth loss fading. will be carried out.

Effects of the Invention As described above, according to the present invention, the phase angle portions are divided into phase angle ranges in which the rate of change in brightness of the illumination lamp is similar to the change in phase angle, and In the phase angle portion where the rate of change is small, the amount of change in the phase angle for each half cycle of the AC power given to the illumination lamp is increased, and in the phase angle portion where the rate of change is large, the amount of change in the phase angle for each half period of the AC power given to the illumination lamp is increased. By reducing the amount of change in each phase angle and controlling the brightness change rate at each phase angle to be uniform,
Crossfading can be performed smoothly.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the electrical configuration of an embodiment of a dimmer according to the present invention, FIG. 2 is a waveform diagram showing the characteristics of each control part of the dimmer, and FIG. 3 is a detailed diagram of the present invention. FIG. 4 is a 70-chart showing the control operation of the CPU 1 of the present invention, FIG. 5 is a flowchart showing typical prior art dimming control, and FIG. 6 is a graph showing the voltage of the commercial AC power supply. The waveform diagram in FIG. 7 is a graph showing the dimming characteristics of a lighting lamp to explain the prior art. 1...CPU, 2...key manual means, 3...power synchronization signal generation circuit, 4...commercial AC power supply, L1 to Ln
...Lighting lamp, A...Current dimming data, B...Dimming data of next scene, t...Cross time, Fl...
・7 lags for up/down, P1 to P3... section of dimming data, H1 to H3... number of change stages of dimming data, K1
- to 3...Number of up and down cycles in each section, N.
...Total number of up and down cycles, F5...Work area N I...N's work area/Agent Patent attorney Number of strokes Keiichi - Gakugeme procedure correction ■ October 24, 1985 Tokugansho 59-224476 2. Name of the invention Light control method 3. Relationship with the person making the amendment Applicant's address Name (583) Matsushita Electric Works Co., Ltd. Representative 4, Agent address 1-13-38 Nishihonmachi, Nishi-ku, Osaka No. Shinyosan Building Country Equipment EX 0525-5985 1NTAPT
J International FAX GI&G TJ (06)538-0
247G1 The detailed description of the invention in the specification subject to the amendment, Drawing 7, and contents of the amendment (1) [RA W J
Correct the statement to I'[AMJ. (2) In line 19 of the specification, [Cross time 1] is corrected to ``Cross time IJ.'' (3) Formula 7 on page 11 of the specification is corrected as follows. ( 4) Correct Figure 7 of the drawings as shown in the attached sheet.

Claims (1)

[Claims] In a dimming method that dims a lighting lamp by controlling its phase angle, a phase angle portion is set for each phase angle range in which the rate of change in brightness of the lighting lamp with respect to a change in phase angle is similar. In the phase angle part where the rate of change is small, the amount of change in the phase angle for each half cycle of the AC power applied to the lighting lamp is increased, and in the phase angle part where the rate of change is large, the amount of change in the phase angle is increased in the phase angle part where the rate of change is small. A dimming method characterized by reducing the amount of change in phase angle for each cycle of alternating current power applied to the lamp, and controlling so that the rate of change in brightness at each phase angle portion is uniform.