JPH0254898A - Lighting device - Google Patents

Abstract

PURPOSE:To enable the easy follow-up of the illuminating direction of an illuminating light to the movement of an object by providing a gaze direction detecting part and a control part and controlling a driving part based on the signal from the gaze direction detecting part. CONSTITUTION:A control part 6 inputs a signal from a gaze direction detecting part 5 and outputs a signal controlling a driving part 3 so that the illuminating direction of the illuminating light from a light source 1 accords with the gaze direction of an observer. The frequency band range of fine vibrations of the human eye is 10-20Hz and 70-90Hz, although it varies depending on the state of the observer. Thus, in the control part 6, the above two band range components of the signals from the gaze direction detecting part 5 are removed, and the driving part 3 is controlled based on the resulting signal. Hence, the rapid follow-up to an object 4 can be achieved without insignificantly moving the driving part 3 due to fine vibration of the eyeball of the observer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lighting device used, for example, in a security system or a headlight for a vehicle.

2. Description of the Related Art A block diagram of a conventional illumination device is shown in FIG. 3. In FIG. 3, 1 is a light source, 2 is a power supply circuit, 3 is a drive unit, and 4 is an object to be illuminated. The light source 1 generally needs to have a sufficient amount of light and a high uniformity of illuminance. Therefore, the light source 1 generally includes a high-pressure discharge lamp such as a metal halide lamp with good luminous efficiency, and an optical system for effectively utilizing the light emitted from the lamp. Power outlet I! Reference numeral 82 supplies a constant current to the light source 1, and generally includes a commercial power source and a magnetic circuit type ballast. The drive unit 3 changes the direction of illumination light emitted from the light source 1 vertically and horizontally at regular intervals, either manually by the observer or driven by a motor. In the illumination device configured in this way, the light source 1 can condense light in a narrow range to obtain a sufficient amount of light on the illuminated surface, and scan a wide range to detect the object 4 on the illuminated surface.

Problems to be Solved by the Invention In the conventional illumination device configured as described above, when the object 4 is moving, the drive unit 3 is operated to follow the irradiation direction of the illumination light according to the movement. It required skill to do so.

In addition, the current frequency supplied from the power supply circuit 2 is 50 or 60 Hz, and when the light source 1 is composed of a discharge lamp, if the discharge is not performed symmetrically in positive and negative directions per cycle of the current, the frequency of the current emitted from the light source 1 is 50 or 60 Hz. The frequency of the illumination light is 50 or 60 Hz, the same as the current frequency, and there is a problem in that flickering may be perceived. Further, the intensity of the light output emitted from the light source 1 fluctuates at a frequency of 100 or 120 Hz even when discharge is performed symmetrically in the positive and negative directions within the discharge lamp constituting the light source 1. For this reason, when observing the object 4 that is moving at an extremely fast speed, there is a problem that the object 4 may be lost because the illumination light repeats brightness and darkness over time.

Means for Solving the Problem The line-of-sight direction detection unit is composed of a light source, its power supply circuit, a drive unit that changes the irradiation direction of the light emitted from the light source, and a line-of-sight direction detection unit that monitors the direction of the observer's line of sight. The drive unit is controlled based on signals from the

The irradiation direction of the action illumination light can be easily made to follow the movement of the object.

Embodiment A block configuration diagram of an embodiment of the lighting device according to the present invention is shown below.
In FIG. 1 shown in the figure, 5 is a line-of-sight direction detection section, and 6 is a control section. The line-of-sight direction detection unit 5 is for detecting the line-of-sight direction of the observer. For example, an eye mark camera or the like irradiates the eyeball with an infrared beam from a certain direction, and from the reflected light intensity of the beam, A device that can detect the boundary between the cornea and sclera, which have different reflectances, and determine the direction of the line of sight is used. In addition, a device (EO
A similar effect can be obtained using G).

The control unit 6 inputs the signal from the line-of-sight direction detection unit 5 and outputs a signal for controlling the drive unit 3 so that the direction of illumination light from the light source 1 matches the line-of-sight direction of the observer. With the illumination device configured in this way, even when the object 4 is moving at high speed, the direction of irradiation of the illumination light from the light source 1 can be changed according to the movement, and the object 4 can be constantly illuminated. It becomes possible. Since the irradiation direction is changed to be the same direction as the observer's line of sight, the object 4 can be illuminated more reliably than when the drive unit 3 is operated manually, and the operation of the drive unit 3 is easier. No skill required.

Regarding the flickering of the illumination light from the light source 1, the limit frequency at which the human eye perceives flickering is about 100 Hz. In FIG. 1, by using the power supply circuit 2 as an electronic circuit type ballast and lighting the light source 1 at a high frequency of at least 100H2 or higher, it is possible to prevent flickering corresponding to the power supply frequency that occurs when lighting is performed at commercial tWI. Furthermore, although it depends on the type of light source, by setting the power supply frequency to several tens of kHz or more, the waveform of the illumination light emitted from the light source 1 can be regarded as almost a direct current. Therefore, when tracking the moving object 5, brightness and darkness occurring at a frequency twice the power supply frequency does not pose a problem.

The human eyeball has the property of vibrating minutely even when the human eyeball is concentrating the gaze on one point. Therefore, when the control unit 6 transmits information on the direction of the line of sight based on the signal from the line of sight direction detection unit 5 to the drive unit 3 as is, the drive unit 3 detects minute movements unrelated to the movement of the object 4. will be done. In particular, if the moving direction of the object 4 is opposite to the direction of minute movement in the direction of the line of sight based on the vibration of the observer's eyeballs, the object 4 is removed from the range of the illumination light from the light source 1. Sometimes. The frequency band of minute vibrations in the human eye varies depending on the situation of the observer, but
0 Hz and 70 to 9 QHz (for example, Goto et al.: Proceedings of the 39th Japan Society of Applied Physics Academic Conference p213 (
1978)). Therefore, in the control unit 6, the two band components are removed from the signal from the line-of-sight direction detection unit 5, and the drive unit 3 is controlled based on the resulting signal, so that the observer's eyeball Drive unit 3 due to minute vibrations
It is possible to provide a lighting device that can quickly follow the object 4 without causing any meaningless movement.

When the lighting device according to the present invention is applied to a vehicle headlamp,
Compared to headlights that illuminate a wide area, it is possible to illuminate the area that the driver is focusing on with a sufficient amount of light.
Leading vehicles/oncoming vehicles, road signs, obstacles, pedestrians/bicycles/
You can accurately obtain the information necessary for safe driving such as motorcycles. In addition, as shown in Figure 2, when driving around a curve, conventional headlights have a fixed direction as shown by the broken line, so oncoming lanes that are not necessary for driving information are illuminated. However, since the driving lane is only illuminated very close to the vehicle, there is a problem in that obstacles in the driving lane cannot be seen until the very last moment. When the illumination device according to the present invention is used as a vehicle headlamp, it becomes possible to illuminate even the driving lane ahead as shown by the solid line in Fig. 2, which makes it easier to find obstacles on the driving lane. This allows for faster response to obstacles and improved safety.

In the embodiments of the present invention, the light source 1 may be a high-pressure discharge lamp, a low-pressure discharge lamp such as a fluorescent lamp, or a light bulb. The power supply circuit 2 may be of any type as long as the above light source 1 can be provided over the counter. The drive unit 3 is not limited to one using a motor as in the conventional example, but may also be one using a shape memory alloy, hydraulic It may be driven by other means, such as one using.

Effects of the Invention The irradiation direction of the illumination light can be easily made to follow the movement of the object.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of an embodiment of the lighting device according to the present invention, FIG. 2 is a diagram showing an example of the effect when the lighting device according to the present invention is used as a vehicle headlamp, and FIG. 3 is a diagram showing a conventional lighting device. FIG. 2 is a block configuration diagram of a lighting device. DESCRIPTION OF SYMBOLS 1... Light source, 2... Power supply circuit, 8... Drive part, 4
...Target, 5... Line-of-sight direction detection section, 6... Control section. Figure 2 Figure 3

Claims (2)

[Claims] (1) A light source, its power supply circuit, a drive unit that changes the irradiation direction of light emitted from the light source, a line-of-sight direction detection unit that monitors the direction of the observer's line of sight, and a signal from the line-of-sight direction detection unit. and a control section that controls the driving section based on a signal from which a signal in a frequency band of minute movement of a human's line of sight is removed. (2) The lighting device according to claim 1, wherein the light source is a vehicle headlamp.