JPS6214695A - Lighting controller for color varying fluorescent lamp - 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 1] The present invention relates to a lighting 11J control device for a variable color fluorescent lamp used in a large color display device.

Conventionally, variable color fluorescent lamps of this type used in large color display devices have been designed as shown in FIGS. 4 to 7. That is, this variable color fluorescent lamp has a U-shaped part 1a, 1b, which is made up of three U-shaped glass tubes.
1 c, and a rectangular parallelepiped part 2 formed of a lath board, and the inner surfaces of the U-shaped parts 1 at i b and 1 c are filled with phosphors of different luminescent colors (for example, red phosphors). , green phosphor, blue phosphor).
Each U-shaped part 1a.

A light emission control electrode, that is, an anode 3i3b, 3c is sealed to one end of 1b, 1c. On the other hand, the front surface of the rectangular parallelepiped part 2 has communication holes 5 at 5 b, 5 which communicate with the other open ends of the U-shaped parts 1 a, 1 b, 1 c.
The rectangular parallelepiped part 2 has a hole c and serves as a common discharge space.
Each anode has 31L inside.

A common electrode, that is, a common cathode 4, is provided as a pair with 3b and 3c. Further, an auxiliary electrode, that is, an auxiliary anode 3d, which does not contribute to light emission, is provided on the side of the common lii:pole 4 provided in the common discharge space. Here, from the U-shaped part I Ill 1 b, 1 c and the rectangular parallelepiped part 2? -L4h'II Woo5flB+↓hLfdlLheri-AoJ1. -11+mjtGoJ+L+Ii+1% A rare gas and a metal vapor gas such as mercury are sealed inside. In addition, a light shield (not shown) is provided on the outer surface of the rectangular parallelepiped portion 2.
is covered.

FIG. 8 shows an example of a basic circuit of such a lighting control device for a variable color fluorescent lamp, in which a DC power supply 8 connects each anode 3a, 3 via a selection changeover switch contact 7 for switching the discharge path.
b, 3c and the auxiliary anode 3d, and by controlling the discharge switching timing, the emitted light color is changed. In addition, each anode 3 a, 3 b
, 3c, each of the rising auxiliary anodes 3d has a current limiting element 6
A to 6c are connected in series so that a constant lamp current flows. In the figure, a starter 9 generates high voltage at the time of starting.

Specifically, as shown in FIG. 9, the selection switch circuit 7 includes switching transistors Qa, Qa', Qb-- whose on/off duties are made variable by a control circuit.
Qb', Qc-Qc', Qd, and Qd' are formed, and a DC power source 8 is applied to each anode 3a, 3b, 3c and auxiliary anode 3d at appropriate timing to switch the discharge path. The above control circuit includes a clock pulse generator PG, a ring counter LC that counts the clock output from the clock pulse generator PG and sets a light emission period for each color, and a lighting circuit that generates a lighting control signal that controls light emission of each color. Signal generator S Ga1S G
b, S Gc, and a date circuit GC consisting of AND circuits A1 to A and inverter circuits 11 to I.

Figures 10 and 11 show each anode 3a, 3b,
3 c and a time chart showing the timing at which DC power is applied to the auxiliary anode 3 d (switch contacts 7 a to 7 d
), and within each repetition period T set by the clock pulse generated by the clock pulse generator PG, there is a red light emitting period T, a green light emitting period Tc, and a blue light emitting period Tc. The light emitting enabled period T is set, and the light emitting enabled periods TR9Tc and T8 of each color are fixedly set to be equal. Further, the repetition period T is set so that flicker does not occur due to switching. FIG. 10 shows the power application state for the brightest light emitting state fi (a state in which light is emitted over the entire period of each possible light emitting period T R, T , , T ). Note that the light emitting positions of each color are not at the same position, but the actual light emitting period of each color can be determined by observing from a sufficiently long distance or by using a diffusion means.
/2, the brightness is 1/2 compared to the case of FIG. 9, and the light emission state is 50% dimming. In this case, during the period when discharge is occurring between the common @ electrode 4 and the auxiliary anode 3d, the phosphor does not emit light, and the phosphor appears to be in an off state, which is a period in which the phosphor is off. In addition,
This luminous body is completely turned off during the off period! ! ! (discharge stop state), but if the completely turned off state is repeated, there is a problem that the temperature change of the common cathode 4 becomes severe and the life of the common cathode 4 is shortened. Therefore, a constant current is made to flow through the common cathode 4 by causing discharge to occur between the light emitting body and the auxiliary anode 3d during the period when the light emitting body is not in use.By the way, in such a lighting control device, the light emission period T R9T of each color is c-T
o is fixedly set to be equal, and the lamp input power that contributes to light emission of each color in the brightest light emission state (operation state shown in Figure 10) is almost constant, but the brightness of each color For example, luminance), green emission>red emission>blue emission. Here, when trying to realize a white light emitting state with an arbitrary color temperature where the brightness is approximately the same for each color (brightness ratio is 1:1:1), the actual light emission of green light and red light is The period is the period during which light can be emitted T Ry T
Therefore, there is a problem that the light emitting efficiency cannot be set to the maximum because there is a period in which the light emitter stops.

[Object of the invention] The present invention has been made in view of the above points, and its -
The aim is to achieve a white light emitting state with any color temperature while maximizing luminous efficiency, and to infiltrate it with 2 * plasters and lamps. be.

[Disclosure of the Invention 1 (Example 1) Figure 1 shows the main part specific circuit of an embodiment of the present invention,
In the lighting control device similar to the conventional example shown in FIGS. 8 and 9, the light emission period of each color is TR+ T C* T
A light emission period setting circuit 10 for arbitrarily setting B is provided in the selection changeover switch circuit 7 instead of the ring counter LC, and the light emission period setting circuit 10 includes four one-shot 7 lip 70 tabs F, -. It is formed by F. The pulse widths of the pulses generated at each one seat 7 lip 70 knob F, - F4 are set by external capacitors CI - C4 and resistors R1 - R4, and are colored red and green. Light emission period T R-T c
The resistors R2, R, which set the value are formed by a volumetric volume.

The operation of the embodiment will be described below. Now, by setting the resistance value of the resistors R2-R3 made of polyneem to *9, the light emission period TR, Tc corresponding to red light emission or green light emission can be arbitrarily set, and the light emission period TR, Tc corresponding to red light emission or green light emission can be set arbitrarily. If T is a repetition period set by a clock pulse, the light emission period T, 3 corresponding to blue light emission is T B = T (T R +
T c), for example,
The light emitting periods TRvTc and TB for each color are set as shown in FIG. 2, taking into consideration the light emitting efficiency of the phosphor of each color. Here, if the luminescence possible periods TR, TC, and TB are set so that the luminance of each luminescent color is the same (the luminance ratio is 1:1:1), white light will be produced when light is emitted over the entire period. A light emitting state is obtained, and the color temperature of the white light emitting state can be changed by adjusting the light emitting enabled periods T, , Tc and varying the brightness of each light emitting color. In this case, it is possible to eliminate the luminescent body dead period in the white light emitting state, so that the luminous efficiency can be maximized. Figure @3 is a time chart when the light emitting period of each color is approximately 1/2 and the light is dimmed by 50% to achieve a white light emitting state.

The light emitting period setting circuit 10 may have any circuit configuration as long as it can set the light emitting period as shown in the time chart of FIG. 2, and is not limited to the embodiment shown in FIG. Needless to say.

[Effects of the Invention] As described above, the present invention provides a variable color fluorescent lamp in which a discharge path for emitting light of a plurality of colors is formed in a shared discharge space. In a lighting control device for a variable color fluorescent lamp, the lighting control device changes the emission color by controlling the discharge switching timing of a selection changeover switch circuit. Since it is provided in the selection changeover switch circuit, there is an effect that a white light emitting state of any color temperature can be realized while the light emitting efficiency is maximized.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a main part of an embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams of the same operation as above, FIG. 4 is a perspective view of a variable color fluorescent lamp according to the present invention, and FIG. Cutaway front view, Figure 6 and! Figure #7 is a partially cutaway side view of the same as above, Figure 8 is a diagram showing the basic configuration of the lighting control circuit, Figure 9 is a block circuit diagram showing the specific configuration of the conventional example, and Figures 10 and 11 are the same as above. FIG. 7 is a selection switch circuit, and 10 is a light emission period setting circuit. Agent Patent Attorney Ishi 1) Chief 7Figure 2Figure 3Figure 4'M7Figure 8Figure 10Figure 1!11Figure

Claims (1)

[Claims] (1) A discharge path that emits light of multiple colors is formed in a shared discharge space. Power is applied to the discharge electrodes that emit light of each color via a selection switch circuit, and the discharge switch of the selection switch circuit is switched. A lighting control device for a variable color fluorescent lamp in which the emission color is changed by controlling the timing, characterized in that a light emission period setting circuit for arbitrarily setting the light emission period for each color is provided in the selection changeover switch circuit. A lighting control device for variable color fluorescent lamps.