JPS63227436A - Car lamp controller - Google Patents

Abstract

PURPOSE:To make brightness of a headlamp variable according to the outside brightness, by determining a duty making the headlamp go on or out according to the outside brightness detected by a light receiving element, and controlling a semiconductor switch by the duty signal. CONSTITUTION:A light receiving element 2 is installed in a controller 1 duty- controlling head lamp illuminance, incoming light from the outside, namely, outside light 4 is guided by an optical fiber 3 and it is made incident into the light receiving element 2. And, at the controller 1, a duty, making a headlamp 15 go ON or OFF according to intensity of the incident outside light 4 is determined, and such a duty control signal 13 that has the duty and consists of a pulse train in speed to be seen as continuous lighting in the sense of sight for a human being is emitted. This duty control signal 13 is fed to a semiconductor switch element 14, and the headlamp 15 is controlled to go ON or OFF whereby a quantity of light is controlled in succession.

Description

DETAILED DESCRIPTION OF THE INVENTION (7) Technical Field The present invention relates to a vehicle light control device that turns on and off headlamps of an automobile and controls the amount of light when they are turned on.

In particular, there are novel points regarding light amount control during lighting.

(a) Prior Art Generally, the headlights of automobiles are turned on and off manually by the driver. However, there are some devices that automatically turn on and off the lights. The basic idea is that a sensor detects the outside brightness and automatically turns on the headlights if it's dark outside.

(1) Headlights that detect external brightness
, automatic lighting/extinguishing devices for small lamps have already been put into practical use. Functional parts will be explained with reference to FIGS. 5 and 6. This is sold under the trade name Conlight.

In FIG. 5, there is a light-receiving element having a circular light-receiving portion, which senses external light. This is connected to an IC containing a control circuit through a large number of leads and lead patterns.

FIG. 6 shows an outline of the circuit portion. This control circuit receives signals from the light-receiving element, the IG switch, and the door open switch, and processes the turning point. The processing circuit turns on and off the small lamp and headlamp by opening and closing the small relay and head relay.

When the ``AUTO'' switch is open, it becomes a manual light on/off mode, and when it is closed, it becomes an automatic light on/off mode.

The door open switch is a switch that detects whether the door is open or closed. There is also a courtesy switch. It is necessary to turn off the headlamps and small lamps after a certain period of time after the door is opened, but this requires human power to signal from the door opening switch.

(II) The above-mentioned conlight turned on and off depending on the brightness of the outside world. There is a problem in that the light-receiving surface of the light-receiving element must be located directly outside.

The inventor has already invented and filed an application for a structure in which a light receiving element is mounted in a control circuit and external light is guided to the light receiving element through an optical fiber.

(IiD Figures 3 and 4 show the lamp on/off switch circuit.

The headlights may be turned on or off by directly using a switch, as shown in Figure 3. Here, there are two lamps, high beam and low beam, so three switches are required. In any case, the on/off state will be switched using a common bistable switch,
That state can be maintained.

Turning on and off the headlamps can also be done via a head relay, as shown in Figure 4. When the headlamp SW is closed, the relay is excited and the headlamp turns on. Of course, switching between high and low beams can be done with a separate switch.

In this way, turning on and off can be done by using a switch directly or by using a relay. Semiconductor elements are never used as switching elements to turn on or off.

6V) Headlamp brightness control is high beam/
This is done by switching the low beam. There is nothing else like this.

However, some countries have legal regulations. There is a law that states that when driving during the day, a headlamp must be lit with an intensity of 10% to 90% of the amount of light at night.

For this purpose, a circuit as shown in FIG. 7 is used.

Inside the control circuit is a day/night switching logic circuit, which switches the terminals of the relay.

One of the relay terminals is directly grounded, and the other terminal is grounded through a resistor. At night, switch the relay to the side with less resistance to emit a stronger light.

During the day, it is connected in series with a resistor, and the amount of light is limited by the resistor.

sec) Problems to be solved by the invention The conventional technology for turning on and off headlamps has been explained.

Automatic lighting/extinguishing devices simply turn on the lights at night and do not turn them on during the day. The amount of light from lamps is not adjusted.O Also, some countries reduce the amount of light from lamps during the day. However, this method uses a resistor to reduce the amount of light, so it only remains at a constant value.

The lamp light intensity cannot be adjusted. Furthermore, since the resistor generates heat, it is wasteful as a means to limit the amount of light. The resistor must also be a large, expensive resistor, and there is also the problem of heat dissipation.

Even though it is night, there are varying degrees of light and darkness, from twilight to darkness. It's not always a constant darkness.

It is desirable to turn on the lamp weakly when the outside world is bright, and turn on the lamp strongly when the outside world is dark. The lamp intensity is continuously variable.

In order to make the amount of light from the lamp continuously variable, it is conceivable to connect a resistor as shown in Figure 7.

However, there is no such thing as a variable resistor that generates a large amount of heat, and even if one could be made, it would be expensive.

You could also consider connecting a lamp to the collector of the transistor and continuously changing the lamp current.

However, the lamp current is generally large, reaching several tens of amperes. It is difficult to control such a large current with a transistor. It also generates a lot of heat and requires expensive transistors. Not realistic.

In this way, it is impossible to change the light intensity of the lamp by changing the current value.

B) Structure The present invention provides a vehicle lighting control device that not only simply turns on a headlamp but also continuously adjusts the amount of light from the headlamp in accordance with external light.

Let A be the intensity of outside light. Here, I is normalized and expressed as a value between O and 1. Conventionally, it was binarized into A=O and 1,
It was lit when A=O, and turned off when A-1.

In the present invention, the lamp light amount Σ is changed as a continuous function with respect to the external light A without being binarized.

Σ=f(i (1)) When A is O, Σ is increased, and when A is 1, Σ is decreased.

Let Σ be a normalization function of the lamp light amount taking a value of 0-1.

(1) is a decreasing function with respect to A, but the type of decreasing function can be set arbitrarily.

Furthermore, in order to change Σ, in the present invention, the headlamp is turned on in pulses. In other words, lighting and extinguishing are repeated at a short cycle T. The lighting time is Q1 and the light-off time is S.

T=Q+S (2). Duty D is defined by D -- (3). The light amount Σ of the lamp increases as the lighting time Q is longer and the extinguishing time S is shorter.

Although human visibility is not proportional to the amount of optical power of the lamp, when the duty D is large, the amount of light Σ perceived by humans also becomes large. Therefore, Σ and D are approximately equal.

Σ-! It is thought that D (4). Although the relationship between Σ and D can be determined through experiments, the present invention can be practiced without knowing the exact relationship between Σ and D.

Duty control of lamp lighting has never been done before. Duty cannot be controlled using a switch. It is also not possible to control duty with a relay with contacts. This is because the relay contacts wear out quickly and cannot be opened or closed. Also, the noise caused by the opening and closing of the relay is unpleasant.

Therefore, in the present invention, a semiconductor switch element is used to turn on and off the headlamp.

Here, the semiconductor switch elements include bipolar transistors, FETs, and Cyrisk.

For example, when a transistor is used, a saturation voltage remains between the collector and emitter when it is on. This depends on the transistor, but is approximately 0.1 to 0.2V.

Since the lamp has a large current value, the transistor generates a considerable amount of heat when it is turned on. However, if it is a power transistor provided with cooling fins or the like, this level of heat generation is not a problem.

The present invention will be explained in detail with reference to FIG.

The control device 1 turns the headlamp on and off depending on conditions such as the brightness of the outside world, opening/closing of a door, and automatic switching, and when the headlamp is turned on, controls the illuminance of the headlamp on a duty basis.

The control device 1 is provided with a light receiving element 2 . This is a light receiving element for detecting the brightness and darkness of the outside world.

pin photodiode, avalanche photodiode,
These include photocells and phototransistors. Since the purpose is to see the degree of optical obstruction of the DC component in the outside world, it does not need to have fast dynamic characteristics. Sensitivity becomes more important. Also,
It is desirable to have stable temperature characteristics.

Even if there is a temperature fluctuation, it is sufficient to perform temperature compensation in the subsequent circuit.

Light entering from the outside world, that is, external light 4 is guided by the optical fiber 3 and enters the light receiving element 2 . The optical fiber may be short. For example, fused silica fiber, fused silica core, plastic clad fiber,
Plastic fiber (PMMA etc.) can be used.

The control device 1 is a circuit including an integrated circuit element, and in addition to the light receiving element 2, an IC, a resistor, a capacitor, etc. are incorporated in a printed circuit board or the like as necessary. This can be incorporated into an active junction block.

The control device 1 has a battery connection line 5, an ignition switch connection line 6, and a ground connection line 7. In addition, it is connected to several switches so that the headlamp 15 can be turned on or off in automatic or manual mode.

The control device 1 is connected to a door open switch 8, an auto changeover switch 9, a small lamp switch 10, a headlamp switch 11, a high beam switch 12, and the like.

The door open switch 8 is a switch for inputting a signal regarding the open/closed state of the door. There is also a courtesy switch. This functions as a sensor together with the light receiving element 2 and the like. The headlights must be turned off automatically after the door is opened, but this requires input from the door open switch.

Of course, it is also possible to use wheel speed sensors to monitor the vehicle speed. However, even if the vehicle has stopped, it does not necessarily mean that the lights should be turned off, so information from the door open switch is more reliable as a signal for turning off the lights after the vehicle has stopped.

It is also possible to input the output from the wheel speed sensor to the control device 1 and use it complementary to the signal from the door open switch 8.

The auto changeover switch 9 is used to switch the mode between an automatic on/off mode or a manual on/off mode.

The small lamp switch 10 is for turning on and off the small lamp in manual mode.

The headlamp switch 11 is a switch for turning on and off the headlamp in manual mode.

The high beam switch 12 is a switch for switching between high beam and low beam, and also plays a role in manual mode.

The control device 1 calculates the duty D according to the intensity A of external light. For period T, on time Q1 and off time S, (2)
There is a relationship like a formula.

Two or three of T and Q%S are changed to give the duty D.

The lamp must appear to the human eye to remain lit. There should be no appearance of flickering. Therefore, the blinking period T is about several tens of m5ec at the longest.

The duty D is T%Q%S according to equations (3) and (2).
limit. It is also possible to keep T constant and to vary S and Q in a complementary manner.

It is also possible to keep Q constant and vary S and T.

Alternatively, Q and T may be varied while S is kept constant.

A duty control signal 13 is sent from the control device 1 to the semiconductor switch element 14 .

The headlamp 15 lights up for a time Q out of the period T,
At time S, the lights are turned off. The blinking cannot be seen by the human eye. However, the overall brightness changes depending on the duty. In this way, the amount of light can be continuously controlled.

Continuous control of the amount of light will be explained with reference to FIG.

FIG. 2 (,) illustrates a temporal change in the brightness A of the outside world. Suppose that the outside world is changing from bright to dark in this way. (b) shows the headlamp control pulse. When A is large, the duty is small, and when A is small, the duty is large. (c) shows the brightness Σ of the headlamp. When the duty is small, the light is dimly lit. As the duty increases, the brightness of the headlamp increases.

In this way, the brightness Σ of the headlamp is controlled reciprocally with respect to the brightness A of the outside world.

In reality, areas where the duty is 0 and areas where the duty is 100% are often provided near A=0 and Δ=1. For convenience of explanation, in FIGS. 2(a) to (C), Δ=
The whole number from 0 to 1 indicates that the brightness of the headlamp is changed continuously.

In addition to continuously changing the illuminance of the headlamp, the present invention can perform an operation equivalent to conventional switching between high beam and low beam.

Moreover, instead of using two lamps, only one lamp is required.

Further, the small lamp can also be turned on automatically depending on the amount of light Δ in the outside world.

For this reason, the amount of light A in the outside world is set to three threshold values, L.

Classify by H.

K > L > H (1) It is.

When the amount of light A in the outside world becomes less than K, the small lamp is turned on.

Small lamp lighting conditions A≦K (2) External light amount A
When the value becomes less than L, the lamp is lit in pulses at a certain duty D1. This replaces traditional low beams. This is called the low beam lighting condition.

Low beam lighting conditions H≦A≦L (3) External light amount A
When the value becomes H or lower, lighting is performed with a duty of 100% (D=1). This is called ノ)ibeam. This is because it is equivalent to conventional high beam lighting.

FIG. 2(d) shows turning on and off of the small lamp.

When the temperature falls below A, the small lamp lights up.

FIG. 2(e) shows the headlamp control pulse. A is L
A pulse with a certain duty D1 is generated when the value is below H, and a waveform with a 100% duty is generated when the value is below H. The headlamp light intensity is shown in FIG. 2(f). Initially, the light amount is O. When A=L, it lights up although the amount of light is weak. When A=H, it lights up completely.

This allows you to effectively switch between high and low beams.

(3) Example An example is shown in FIG. This can also be applied to legal regulations, and switches between low beam and low beam using a single headlamp. In addition, the small lamp is also a substitute for the headlamp.

(1) Assume that the ignition switch is off and the auto switch is off. In other words, it is a manual mode where you manually turn on or off the light.

Since it is in manual mode, the light turns on and off as per the operation.

Turn on the headlamp switch among the light switches.

If you switch to high beam, it will turn on at 100% duty.

If you switch to low beam, the light will turn on with duty set to α. This turns on the headlamp, but 1
The illuminance is lower than that at 00% duty, effectively corresponding to a low beam.

Assume that among the light switches, the small lamp switch is turned on. In this case, the headlamp turns on at duty β.

100%>α%>β% (4). Since the duty is low, although it is a headlamp, the illuminance corresponds to a small lamp. When you turn off the light switch, the light goes out.

(ti) the ignition switch is off;
AND) Assume that the SW is on. In other words, the lamp is in manual mode even though it is stopped.

If the automatic lights-off conditions are met, the headlights will turn off. If not established, the headlamp continues in its previous state.

The automatic light-off condition can be freely set, such as when a certain period of time has elapsed since the door was opened.

(iiQ Assume that the ignition switch is on and the auto switch is off. In other words, the vehicle is running but in manual mode.

Turn on the head switch. If you switch to high beam,
Lights up at 100% duty. If you switch to low beam, it will dot with duty α%. Suppose you turn off the head switch. There is a distinction here between whether a country is a legally regulated country or not. In non-legally regulated countries, when the small switch is on, the headlights are turned on with a duty of β%. When the small switch is off, the headlamp turns off.

This is natural since these are manual modes. However, in countries with legal regulations, even if the head switch is off,
As long as the vehicle is in motion, the lights must be on according to legal regulations. Therefore, the headlights are turned on with a duty of α× (legally regulated value).

Assume that the dVl ignition switch is on and the so-called auto is on. It is in automatic on/off mode while driving.

The outside light determination circuit determines whether it is night or day outside. At night, the lights turn on either high beam or low beam depending on the brightness. This is a question of whether it is below or above the threshold H in FIG. 2(a).

If the vehicle is on high beam, the headlights will turn on with a duty of 1.00%. If it is a low beam, the headlights will turn on at duty α%.

If it is not night outside, the next question is whether the country is not a country with legal regulations or is a country with legal regulations.

Unless you are in a country with legal regulations, the brightness outside will be a problem. If it is evening, the small lamp should be turned on, so the headlamp is turned on at duty β%.

If the brightness outside is daytime, turn off the lights.

In countries with legal regulations, α × (legal regulation value) even during the daytime.
Turn on the headlights.

In this way, according to the present invention, the amount of light in the outside world can be observed as a continuous amount, and switching between high beam and low beam can be performed automatically. Small lamps can also be replaced by headlamp duty control.

(2) Effects (1) Since the duty of the control pulse is changed according to the amount of light in the outside world, the amount of light from the headlamp can be reduced to a value smaller than when the headlamp is turned on completely. Therefore, the amount of light from the headlamp can be changed continuously.

(2) Since semiconductor switching elements are used instead of opening and closing switches or relays, the lights can be turned on and off quickly. I don't know that it's blinking, and it seems like it's on continuously.

(3) By changing the light intensity of the headlamp in stages, conventional high beam/low beam switching can be performed using a single lamp.

(4) Going even further, small lamps can also be replaced with headlamps. In the end, all three lamps - high beam, low beam, and small lamp - can be used instead.

(5) Since external light is guided using an optical fiber, the degree of freedom regarding the installation location in the vehicle of the control device equipped with the light receiving element is increased.

(6) It is easy to deal with countries with laws and regulations that require lights to be turned on with an intensity of 1096 to 90% of nighttime light even during the day. Daytime lighting can be done simply by changing the duty. Since no resistor is used, the number of parts can be reduced. You can avoid the problem of heat generation and save energy.

(7) Semiconductor switches have an overcurrent prevention function.

In this respect, it differs from switches and relays that have mechanical contacts. The overcurrent prevention function works effectively to prevent lamp inrush current and extend lamp life.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a vehicle lighting control device according to the present invention. FIG. 2 is a waveform diagram showing temporal changes in the amount of light in the outside world. (
(a) is an example of the waveform of the external light intensity, (b) is the headlamp control pulse waveform when it changes continuously, (C) is the headlamp light intensity Σ, (d) is the waveform showing the small lamp on/off state, (e ) is a headlamp control waveform diagram when performing two-stage control, and (f) is a headlamp light amount Σ when performing two-stage control. Figure 3 is a conventional circuit diagram that directly turns on and off headlamps by opening and closing a switch. Figure 4 is a conventional circuit diagram that uses a switch to open and close a relay, thereby turning on and off headlamps. FIG. 5 is a configuration diagram of a conventional detector in which external light is directly incident on a light receiving element. FIG. 6 is a circuit diagram of a conventional example for simply continuously turning on and off small lamps and headlamps depending on the amount of light in the outside world. Figure 7 is a headlamp control circuit configuration diagram within the legal regulations that require lamps to be turned on during the day. FIG. 8 is a flowchart showing the operation in the control mode according to the embodiment of the present invention. 1......Control device 2...Light receiving element 3...Optical fiber 4...・・・
......Outside light 5...Battery connection line 6...Ignition switch connection line 7... ...Ground connection wire 8...Door open switch 9
・・・・・・・・・・・・Auto changeover switch 10...
......Small lamp switch 11...
・・・・・・・・・Headlamp switch 12...
......High beam switch 13...
......Duty (lighting rate) control signal 14...
......Semiconductor switch element 15...
・・・・・・Headlamp inventor Kazuo Hirano Yukihiro Hattori

Claims (4)

[Claims] (1) Vehicle headlights consisting of headlamps and small lamps, a light switch that manually turns the headlights on and off, a vehicle battery that serves as a power source, and a light-receiving element 2 that senses the brightness of the outside world. and the brightness signal Λ from the photodetector
A control device 1 that determines a duty D for turning on and off the headlights based on the above, and generates a duty control signal consisting of a pulse train having the duty and having a speed that appears as continuous lighting to the human visual sense, and the control device The headlamp is comprised of a semiconductor switch element 14 that turns on and off the headlamp in accordance with the duty control signal No. 1, and is characterized in that the brightness of the headlamp is made variable according to the brightness of the outside world through duty control. Vehicle lighting control device. (2) The vehicle lighting control device according to claim (1), wherein the light from the outside world is guided to the light receiving element by an optical fiber. (3) The vehicle according to claim (1), wherein the standardized external brightness Λ and the headlamp duty D have a complementary relationship D+Λ=constant. Light control device. (4) Laws and regulations stipulate that headlamps should be turned on even during the day, so even if the outside brightness Λ is equivalent to daytime or evening, the specified duty headlamps must be turned on. Claim No. 1 (1) characterized in that
) Vehicle lighting control device described in item 2.