JPH07242146A - Lighting dimmer - Google Patents

Abstract

PURPOSE:To improve the operability by selectively connecting two attenuators in series to a luminaire in accordance with brilliance in the outside, so as to automatically switch an adjusting range of lighting brightness, in a lighting dimmer for adjusting brightness of the luminaire in accordance with brilliance in the outside. CONSTITUTION:A lighting dimmer is applied to a black face meter for illuminating instruments of an automobile or the like by a back light source. Now in the daytime, when an ignition switch SW3 is turned on, since a transistor Tr1 is turned off, each transistor Tr2, Tr3 is turned on. As this result, brightness of a lighting lamp 3 is adjusted by a variable resistor VR. In the case of turning on a light switch SW2 in the daytime, when a changeover switch SW4 is turned on, brightness of the lighting lamp 3 can be adjusted. Further, when the light switch SW2 is turned in the nighttime, each headlamp 6 is lighted to turn on the transistor Tr1. As the result, brightness of the lighting lamp 3 can be adjusted by a dropper resistor DR.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suitable illumination dimmer for a black face meter that illuminates instruments such as automobiles with a back light source.

[0002]

2. Description of the Related Art Conventionally, some instruments such as automobiles use a black face meter having an incandescent lamp as a back light source. A black face meter has a protective glass on the front of the instrument that is black smoked glass, and the instrument (pointer, pointer,
The numerical value) will be visible. Therefore, it is necessary to illuminate from the inside from daytime or night.

By the way, since the smoked glass is exposed to the external light in the daytime, it is necessary to increase the brightness in order to improve the visibility. On the other hand, since the surroundings are dark at night, the brightness is too bright in the daytime. , It is necessary to lower the brightness. Therefore, conventionally, an illumination dimmer as shown in FIG. 3 or 4 has been used. In the conventional lighting dimmer shown in FIG. 3,
When the ignition switch SW1 is turned on, power from the battery 1 is supplied to the lighting lamp 3 via the rheostat volume 2. A known variable resistor is used for the rheostat volume 2. By adjusting the rheostat volume 2, the current supplied to the illumination lamp 3 is adjusted to change the brightness.

Further, in the conventional illumination dimmer shown in FIG. 4,
Instead of the rheostat volume 2 using the variable resistor, an astable multivibrator 4 whose on / off time ratio, that is, duty ratio is adjustable is used. This structure is disclosed in Japanese Utility Model Laid-Open No. 2-11796. In this example, the duty ratio is adjusted by adjusting the variable resistor 5 that constitutes the astable multivibrator, and the on-time of the transistor Tr that constitutes the astable multivibrator is changed. As a result, the time width of the current supplied to the illumination lamp 3 is adjusted and the brightness is changed.

The luminance ratio of the illumination lamp by the above-mentioned conventional illumination dimmer is as shown in FIG.
Alternatively, it changes substantially linearly with respect to the adjustment range of 5, and the adjustment is 0 to 100% in the entire variable range of the variable resistor.

[0006]

By the way, in the black face meter, the maximum luminance at night is 1 during the day.
Since it is enough to be about / 5 to 1/10, it is desirable that the brightness at night can be adjusted within a very narrow range (10 to 20% of the whole) shown. However, in the conventional lighting dimmer, the brightness adjustment range is 0 to 100 relative to the entire adjustment range of the variable resistor 2 or 5 in the daytime and the nighttime.
%, The adjustment in the extremely narrow range is delicate and the operability is poor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an illumination dimmer that has a simple structure and can improve operability.

[0008]

In order to solve the above-mentioned problems, in the invention according to claim 1, the illumination dimmer for adjusting the brightness of the luminaire according to the brightness of the outside is variable. A first attenuator having an amount of attenuation and adjusting the brightness of the lighting fixture; a second attenuator having a predetermined amount of attenuation;
When the outside is bright, the first attenuator is connected in series to the luminaire, and when the outside is dark, the second attenuator is connected in series to the luminaire in addition to the first attenuator. And means.

According to the second aspect of the invention, the first aspect is
In the lighting dimmer according to claim 1, the lighting fixture is used for instrument lighting of a vehicle, and the connection switching means links the first attenuator to the lighting fixture in conjunction with an ON operation of an ignition switch of the vehicle. In addition to the first attenuator, the second attenuator is connected in series to the lighting fixture by being connected in series, and in addition to the ON operation of the headlight switch of the vehicle.

According to the invention described in claim 3, claim 1
The illumination dimmer according to claim 1, wherein the first attenuator and the second attenuator are connected in series to the lighting fixture, and the connection switching means includes both the ignition switch and the headlight switch. And a second switch which is turned on when the ignition switch is turned on and is turned off when the first switch is turned on. Means and the second attenuator are connected in parallel, and are turned on when the ignition switch is turned on to short-circuit both ends of the second attenuator to illuminate the first attenuator. It is characterized by comprising a third switch means which is directly connected to the device and which is turned off when the second switch means is turned off.

In the invention according to claim 4, the invention according to claim 3
In the illumination dimmer described, the first, second, and third switch means are transistor elements.

According to the invention described in claim 5, claim 3
The lighting dimmer according to claim 1, wherein the lighting dimmer is connected in parallel to the first and second attenuators connected in series, and when turned on, directly to the lighting fixture without going through the first and second attenuators. It is characterized by comprising switching means for supplying power.

[0013]

According to the first aspect of the present invention, when the outside is bright, the connection switching means connects the first attenuator in series with the luminaire to adjust the attenuation amount of the first attenuator. To adjust the brightness of the luminaire. On the other hand, when the outside is dark, in addition to the first attenuator, the connection switching means further connects the second attenuator to the luminaire in series to add a certain amount of attenuation, and to attenuate the first attenuator. Adjust the brightness of the luminaire by adjusting the amount. Therefore, with a simple configuration, it is possible to automatically switch the brightness adjustment range of the illumination in the daytime and the nighttime and improve the operability.

Further, the above lighting equipment may be used for instrument lighting of a vehicle, and in this case, the connection switching means connects the first attenuator to the lighting equipment in series in conjunction with the ON operation of the ignition switch of the vehicle. In addition to the operation of turning on the headlight switch of the vehicle, in addition to the first attenuator, the second attenuator
The attenuator may be connected in series with the luminaire.

Further, the first attenuator and the second attenuator are connected in series to the lighting equipment, and the connection switching means is turned on when both the ignition switch and the headlight switch are turned on. A first switch means,
When the ignition switch is turned on, it is turned on, while when the first switch means is turned on, the second switch means is turned off, and the second attenuator is connected in parallel, and the ignition switch is turned on. When turned on, the both ends of the second attenuator are short-circuited to directly connect the first attenuator to the luminaire, while when the second switch means is turned off, the third attenuator is turned off. A switch means may be provided.

The first, second and third switch means may be composed of transistor elements. In addition, the switching device is connected in parallel to the first and second attenuators connected in series and, when turned on, directly supplies power to the lighting fixture without passing through the first and second attenuators. You may do it.

[0017]

Embodiments of the present invention will now be described with reference to the drawings. Note that the portions corresponding to those in FIG. 3 or FIG.

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the present invention. In the figure, a light switch SW2 is for turning on / off the headlamps 6, 6, one end of which is connected to the (+) side of the battery 1 and the other end of which is connected to the headlamps 6, 6. One end of a resistor R1 is connected to the connection point between the light switch SW2 and the headlamps 6 and 6, and the other end of the resistor R1 is connected to the transistor Tr.
Connected to the base of 1. Transistor Tr1 is N
It is a PN type transistor, and its emitter is connected to the (−) side of the battery 1.

Further, one end of an ignition switch SW3 is connected to the (+) side of the battery 1,
The other end of the ignition switch SW3 is connected to the collector of the transistor Tr1 and the base of the transistor Tr2 via a resistor R2. The transistor T
r2 is an NPN type transistor, the collector of which is connected to the base of the transistor Tr3 via a resistor R3 and the emitter of which is connected to the battery (-) side.

The transistor Tr3 is a PNP type transistor, a dropper resistor DR is connected between the collector and the emitter, and the emitter is connected to the battery (-) side through a variable resistor VR. There is. The dropper resistor DR and the variable resistor VR are connected in series, and a switch SW4 is connected in parallel to them. The variable resistor VR may be of any type in which a slider that is in contact with the resistor is driven by a rotating shaft or is driven by a slide lever. Further, as the change of the resistor due to the driving of the slider, any of A type, B type, C type, D type, or E type may be used depending on the situation.

The switch SW4 is for preventing the illumination light 3 from becoming dark when the light switch SW2 is turned on during the daytime. The switch SW4 is
It may be independent, or may be provided in the variable resistor VR (so-called variable resistor with S).

The above-mentioned transistors Tr1, Tr2, T
The rheostat circuit 10 is composed of r3, resistors R1, R2, R3, dropper resistor DR, variable resistor VR, and switch SW4.

At the other ends of the light switch SW2 and the ignition switch SW3, a diode D1 is provided, respectively.
, D2 anodes are connected and the diode D1
, D2 cathodes are both connected to one end of the illumination lamp 3. These diodes D1 and D2 are diodes for backflow prevention for turning on the illumination lamp 3 and operating the rheostat circuit 10 normally when either the light switch SW2 or the ignition switch SW3 is turned on. .

The other end of the illumination lamp 3 is connected to the emitter of the transistor Tr3 described above (that is, the connection point of the emitter, the dropper resistor DR, and the switch SW4).

Next, the operation of the above-described embodiment will be described with reference to FIG. FIG. 2 is a state diagram showing the relationship between the adjustment range of the variable resistor VR and the luminance ratio of the lighting lamp 3. When the light switch SW2 is off, that is, during the daytime, when the ignition switch SW3 is turned on, the transistor Tr1 is off, so the transistors Tr2 and Tr3 are on. Therefore, the dropper resistor DR is bypassed, and the lighting lamp 3 is connected to the (−) side of the battery 1 via the transistor Tr3 and the variable resistor VR.

Therefore, in this case, since the current supplied to the illuminating lamp 3 is adjusted only in accordance with the resistance value of the variable resistor VR, as shown in FIG. Adjusted between 100%. In addition, in the above-described state, when the light switch SW2 is turned on, that is, when the light switch SW2 is turned on even though it is until daytime, the switch SW4 is turned on, and as shown in the figure, The brightness of the lamp 3 can be forcibly set to 100%.

On the other hand, when the light switch SW2 is turned on, that is, at night, the headlamps 6 and 6 are turned on and the transistor Tr1 is turned on, so that the transistors Tr2 and Tr3 are turned off. Therefore, the illumination lamp 3 is connected to the (−) side of the battery 1 via the dropper resistor DR and the variable resistor VR. Therefore, in this case, the current supplied to the lighting lamp 3 decreases in accordance with the resistance value of the dropper resistance DR.

If the resistance value of the dropper resistor DR is appropriately determined, the brightness of the illumination lamp 3 is, for example, in the range of 0 to 20% as shown in FIG. 2 according to the adjustment range of the variable resistor VR. Adjusted. In this case, the maximum adjustment value is 20%, but it goes without saying that it can be changed by the resistance value of the dropper resistance DR. In this way, the variable resistor V
Since the brightness can be adjusted at 0 to 20% in the entire adjustment range of R, it is possible to make fine adjustments. Also in this case, if the switch SW4 is turned on, the brightness of the illumination lamp 3 can be forcibly set to 100% as shown in the figure.

In the above-mentioned embodiment, the case where the number of the illumination lamps 3 is one has been described, but the present invention is not limited to this, and a plurality of illumination lamps 3 may be provided as required.

[0030]

As described above, according to the first aspect of the invention, in the illumination dimmer that adjusts the brightness of the luminaire according to the brightness of the outside, it has a variable attenuation amount. ,
A first attenuator that adjusts the brightness of the luminaire, a second attenuator having a predetermined amount of attenuation, and when the outside is bright,
The first attenuator is connected in series to the luminaire, and when the outside is dark, in addition to the first attenuator, there is provided connection switching means for serially connecting the second attenuator to the luminaire. As a result, with the simple configuration, it is possible to automatically switch the brightness adjustment range of the illumination in the daytime and the nighttime, and it is possible to improve the operability. Further, since the structure is simple, there is an advantage that the cost can be reduced.

According to a second aspect of the present invention, in the illumination dimmer of the first aspect, the lighting device is used for instrument lighting of a vehicle, and the connection switching means is an ignition switch of the vehicle. The first attenuator is connected in series to the lighting device in conjunction with the ON operation of the vehicle, and further, in addition to the first attenuator, the second attenuator is connected in conjunction with the ON operation of the headlight switch of the vehicle. Since the attenuator is connected to the lighting equipment in series, the brightness adjustment range of the daytime and nighttime lighting can be automatically switched with a simple configuration, and the operability can be improved. can get. Further, since the structure is simple, there is an advantage that the cost can be reduced.

According to a third aspect of the invention, in the illumination dimmer of the first aspect, the first attenuator and the second attenuator are connected in series to the luminaire. The connection switching means is a first switch means that is turned on when both the ignition switch and the headlight switch are turned on, and is turned on when the ignition switch is turned on. The second switch means, which is turned off when the first switch means is turned on, and the second attenuator are connected in parallel, and are turned on when the ignition switch is turned on. The attenuator is short-circuited at both ends to directly connect the first attenuator to the lighting device, while the second attenuator is connected to the second attenuator.
When the switch means of is turned off, it is turned off.
Since it is provided with the switch means, it is possible to automatically switch the brightness adjustment range of the lighting during the daytime and at night and to improve the operability with a simple configuration. Further, since the structure is simple, there is an advantage that the cost can be reduced.

According to the invention described in claim 4, in the illumination dimmer according to claim 3, the first, second and third switch means are composed of transistor elements, so that the structure is simple. It is possible to automatically switch the brightness adjustment range of the illumination during the daytime and at night and to improve the operability.
Further, since the structure is simple, there is an advantage that the cost can be reduced.

According to a fifth aspect of the present invention, in the illumination dimmer of the third aspect, when the first and second attenuators connected in series are connected in parallel and turned on,
Since the fourth switch means for directly supplying power to the lighting equipment is provided without using the first and second attenuators, the brightness adjustment range of the lighting during the daytime and the nighttime can be adjusted with a simple configuration. The advantages are that the switching can be performed automatically and the operability can be improved. Further, since the structure is simple, there is an advantage that the cost can be reduced. Further, there is an advantage that it is possible to prevent the brightness of the luminaire from decreasing even when the light switch is turned on, even though the outside is bright.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a state diagram showing a relationship between an adjustment range of a variable resistor VR and a luminance ratio of a lighting lamp in the same example.

FIG. 3 is a circuit diagram showing a configuration of a conventional illumination dimmer.

FIG. 4 is a circuit diagram showing a configuration of a conventional illumination dimmer.

FIG. 5 is a state diagram showing the relationship between the adjustment range of the variable resistor and the luminance ratio of the illumination lamp in the conventional illumination dimmer.

[Explanation of symbols]

1 Battery 3 Lighting Lamp (Lighting Fixture) SW2 Light Switch SW3 Ignition Switch SW4 Switch (Switching Means) D1, D2 Diodes Tr1, Tr2, Tr3 Transistors (First, Second,
Third switch means) R1, R2, R3 resistors VR variable resistor (first attenuator) DR dropper resistor (second attenuator)

Claims (5)

[Claims] 1. A lighting dimmer that adjusts the brightness of a lighting fixture according to the brightness of the outside, a first attenuator that has a variable attenuation amount, and that adjusts the brightness of the lighting fixture. And a second attenuator having an attenuation amount of, when the outside is bright, the first attenuator is connected in series to the lighting fixture, and when the outside is dark, the first attenuator is added to the second attenuator. An illumination dimmer, comprising: a connection switching means for connecting an attenuator to the luminaire in series. 2. The lighting device is used for instrument lighting of a vehicle, and the connection switching means connects the first attenuator to the lighting device in series in conjunction with an ON operation of an ignition switch of the vehicle. Further, in addition to the first attenuator, in conjunction with the ON operation of the headlight switch of the vehicle,
The illumination dimmer according to claim 1, wherein the second attenuator is connected in series to the luminaire. 3. The first attenuator and the second attenuator are connected in series to the luminaire, and the connection switching means turns on both the ignition switch and the headlight switch. And a second switch means that is turned on when the ignition switch is turned on, and a second switch means that is turned on when the first switch means is turned on. The second attenuator is connected in parallel, and is turned on when the ignition switch is turned on, and the second attenuator is turned on.
Connecting the first attenuator to the luminaire by short-circuiting both ends of the attenuator, and third switch means that is turned off when the second switch means is turned off. The illumination dimmer according to claim 1, which is characterized in that. 4. The illumination dimmer according to claim 3, wherein the first, second, and third switch means are transistor elements. 5. When connected in parallel to the first and second attenuators connected in series and turned on, power is directly supplied to the luminaire without going through the first and second attenuators. 4. The illumination dimmer according to claim 3, further comprising a switching unit that operates.