JPS62212520A - Lighting apparatus of meter for vehicle - Google Patents

Abstract

PURPOSE:To prevent an abrupt change of brightness in a room even if a shutter is closed, by driving a shutter means when the brightness in the room becomes the same as that of the outside. CONSTITUTION:An external light quantity sensor 1 is provided to a proper place outside a lighting window 2 to detect the brightness of a the outside of a meter chamber. An internal light quantity sensor 3 is provided at a proper place inside the lighting window 2 to detect the brightness in the meter chamber. A comparing circuit 5 compares the output signals of the sensors 1, 3 and drives a drive means 6 when the interior of the meter chamber becomes brighter than the outside to drive a shutter means 7. As the shutter means 7, for example, a blind 8 is used. The blind 8 is supported so that the slates 9...constituting the blind 8 can be shaken around one end sides 9a...thereof and, when the surface of each slat 9 becomes parallel to the lighting window 2, the light from the interior to the outside is blocked. Therefore, even if the shutter 7 is closed, the brightness in the chamber does not change abruptly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a lighting device that is installed in a liquid crystal display meter or the like that utilizes external light and that takes external light into the meter.

(Prior Art) Daylighting devices installed in houses are generally known, and are equipped with a shutter means such as a blind that automatically blocks light in a daylighting window that separates a room from the outside. This daylighting device generally opens the shutter during the day to let sunlight into the room.

At night, close the shutter to prevent light from indoor lighting from leaking outside.

Conventionally, this lighting device is configured to detect external brightness and automatically drive a shutter means when this brightness falls below a predetermined value.

(Problems to be Solved by the Invention) Figures 8 and 9 show changes in the amount of light inside the meter chamber, as well as changes in the amount of external light, in a device in which such a conventional daylighting device is applied to the daylighting window of a liquid crystal display meter that uses outside light. As shown,
Figure 8 shows the change in light intensity when meter indoor lighting is not used, and Figure 9 shows the change in light intensity when meter indoor lighting is used, with the vertical axis showing the light intensity and the horizontal axis showing time. During,
The solid line (20) indicates the amount of external light, and the point &l1j (21) indicates the amount of indoor light measured by the meter.

Now, at sunset, etc., when the outside becomes gradually darker,
The amount of external light also decreases accordingly, and therefore the amount of internal light follows it at a slightly lower value than the amount of external light. At this time, if the shutter is closed when the amount of external light reaches a predetermined value of 1+, the amount of indoor light on the meter will be discontinuously reduced by closing the shutter, as shown in Figure 8, when the meter indoor illumination is not in use. As the amount decreases, the meter room suddenly becomes dark and the meter display also becomes dark, which is a problem.

Also, even if meter indoor lighting is used, the 9th
As shown in the figure, the moment the shutter is closed, the amount of light displayed on the meter decreases discontinuously.

The brightness of the meter display changes discontinuously, causing problems.

In addition, in order to eliminate the discontinuous decrease in the brightness of the meter display, there is a method of closing the shutter 7 after it becomes sufficiently dark outside, but this will cause the light from the meter indoor lighting to leak to the outside, reducing the lighting effect. .

The present invention has been made to solve these conventional problems, and its purpose is to provide the most efficient daylighting device in which the amount of light displayed on the meter does not change even when the shutter is closed. .

(Means and effects for solving the problem) In order to achieve this object, the lighting device according to the present invention includes a shutter means (7) for blocking light in the lighting window (2) separating the indoor and external areas.
A lighting device comprising: an external light amount sensor (1) provided outside the lighting window (2) to detect the brightness of the outside; and an internal light sensor (1) provided inside the room to detect the brightness of the room. a sensor (3), and the external light amount sensor (1).
and a comparison circuit (5) for comparing the output signal of the internal light amount sensor (3), and a comparison circuit (5) for operating the shutter means (7) when the interior of the room becomes brighter than the outside based on the output signal of the comparison circuit (5). A driving means (8) for driving the
According to this configuration, the shutter means (7) is activated when the brightness inside the room and the outside are the same, so even if the shutter is closed, the brightness inside the room will not suddenly change.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

In each figure, the same reference numerals indicate the same objects.

FIG. 1 is a block system diagram showing the overall configuration of a daylighting device according to the present invention, and FIG. 2 is a partially simplified diagram showing a daylighting window.

The external light amount sensor (1) is installed at a suitable location outside the lighting window (2) and detects the brightness and intensity of external light outside the meter room. On the other hand, the internal light amount sensor shown in (3) is
2) inside (0) to detect the brightness inside the meter room. Sawo T
A photoelectric element such as a photodiode or a phototransistor that converts into an L current is used.

The comparison circuit indicated by (5) compares the output signals of the external light amount sensor (1) and the internal light amount sensor (3), and when the meter room (4) becomes brighter than the outside, the driving means (6)
is operated to drive the shutter means (7). This shutter means (7) is, for example, a blind (8) that opens and closes by driving a motor, and in this case, the drive means (8)
) consists of a motor drive circuit, etc.

The blind (8) has each slat (9) that makes up the blind (8).
)... is supported so as to be able to swing around its one end side (8a)..., and when each slat surface is parallel to the lighting window (2), light from the meter room to the outside is blocked. .

At this time, the surface (8b) of each slat (9) facing inside the meter is finished with a coating or the like to increase the light reflection efficiency, improving the lighting effect inside the meter room, The meter display can be made brighter.

Next, a case will be described in which the present device is applied to a motorcycle meter. FIG. 3 is a sectional view of a motorcycle instrument showing another embodiment of the present invention. In FIG. 0, (27) is the steering wheel of the motorcycle, (28) is the handle grip,
29) is a headlight. The instrument (30) is an instrument, such as a speedometer, whose liquid crystal is illuminated by sunlight during the day and by illumination at night, and the instrument (30)
The lighting window (2) is provided with a shutter means (7) for blocking light, and an external light amount sensor (1) and an internal light amount sensor (3) are provided on the outside and inside of the shutter means (7), respectively,
For example, when configured as shown in FIG. 6, which will be described later, the meter (
Since the light leaking from the lighting window (2) can be blocked when the lighting lamp (10) of 30) is turned on, the light transmitted or reflected through the windshield plate (25) can be blocked, and the lighting effect can be improved. Since the display part (2) of the meter (30)
B) will also become brighter. Furthermore, the brightness of the display section (2B) does not change discontinuously, making it possible to obtain ideal instrument illumination. At this time, it is conceivable to use voltage-controlled color-changing glass or the like as the shutter means (7) instead of the blind (8).

Figures 4 and 5 show changes in the meter indoor light amount (display brightness of the liquid crystal meter) with this device, along with changes in the external light amount (outdoor brightness). In this case, FIG. 5 shows the case where meter interior lighting is used.

As explained in the conventional technology (Fig. 8), when the outside becomes gradually darker at dusk (solid line), the meter room also becomes darker (dotted line), but when meter interior lighting is not used (Fig. 4) ), the inside of the meter room is slightly darker than the outside, and the shutter means (7) in this device is not activated. When the predetermined value is reached, the shutter means (7) is driven regardless of the brightness inside the meter chamber, and the problem that the meter display brightness suddenly becomes low does not occur.

On the other hand, when meter indoor lighting is used (Figure 5), when the outside brightness falls below a certain level, the meter display brightness hardly changes in response to the change (after time 1+), and eventually The brightness outside and inside the meter room are the same (time t2), and after that, the inside of the meter room becomes brighter. At this time (time tz), the comparison circuit (5) outputs a signal to drive the shutter means (7). In this case, the brightness inside the meter room and outside are equal, and the conventional technology (Fig. 9)
As shown in Figure 3, closing the shutter does not cause the meter display brightness to change in a discontinuous linear manner; rather, the shutter means (7) prevents light from leaking to the outside, so the illumination effect is further enhanced, and the meter display brightness is increased. The display will become brighter.

FIG. 6 is a block system diagram showing another embodiment of the present invention. In this embodiment, the meter interior light (10) is automatically turned on when the outside becomes a certain darkness. That is, the comparison circuit shown in (11) is the meter indoor light (10).
Use the setting device (external brightness/darkness) to set the
12) and the output signal of the external light sensor (1), and when the external brightness becomes less than the set brightness, the lighting lamp (10) is turned on via the output circuit (13).

FIG. 7 is a circuit diagram showing this other embodiment in more detail.

Each sensor (1), (3) uses cadmium sulfide (CdS) that changes the intensity of light into resistance. This CdS
The resistance value has a property that the resistance value increases as the light becomes weaker.

An external light amount sensor (1) is connected to a power supply in series with resistors R+ and R2, and a change in resistance of the sensor (1) is obtained as a change in potential between resistors R+ and R2 (point A). That is, point A is connected to the input terminals of the comparison circuits (5) and (11) on the positive feedback side via the buffer (15).

As described above, the comparison circuit (5) compares the brightness inside and outside the meter room, and the other terminal is connected to the output side (point B) of the internal light amount sensor (3).

Like the external light sensor (1), the internal light sensor (3) is also connected to the power supply in series with resistors R3 and R4, and the resistance change is obtained as a potential change at point B between the resistors R3*R4. The reason why a variable resistor is used as the resistor R3 here is to adjust the non-uniformity of the characteristics of both sensors (1) and (3). This comparison circuit (5) operates when the potential at point A becomes higher than the potential at point B.

That is, when the inside of the meter chamber becomes brighter than the outside, a high level (H level) voltage is output and the switching transistor (17), which is the drive circuit, is turned on via the filter (16) connected to the output terminal. and drives a shutter means (not shown) connected thereto.

On the other hand, the other input terminal of another comparator circuit (11) receives a value obtained by dividing the power supply voltage by resistors R5 + R6 (potential at point C).
is input. Here, the resistor R5 is a variable resistor used to set the external brightness when the illumination lamp (lO) is turned on. This comparator circuit (11) outputs an H level voltage when the potential at point A becomes higher than the potential at point C, that is, when the external brightness falls below the set value. Similarly, the switch transistor (18
) to turn on the illumination light (10).

Thus, according to this configuration, the shutter means (7) can be automatically driven, and the illumination lamp (10) can also be automatically turned on. This invention further relates to lighting devices for houses, etc., and sunroofs for vehicles, etc.

It can also be applied to window glasses and the like.

(Effect of the invention) According to the present invention, as is clear from the above invention.

Even if I drive the shutter installed in the daylight window of a liquid crystal display meter that uses external light, the meter display brightness is 1! It is possible to always provide the most efficient daylighting device without continuous changes.

[Brief explanation of drawings]

Fig. 1 is a block system diagram showing the overall configuration of a daylighting device according to the present invention, Fig. 2 is a partially simplified diagram showing a daylighting window, and Fig. 3 is a cross section of a motorcycle instrument showing another embodiment of the present invention. Figures 4 and 5 show changes in the meter indoor light amount (display brightness of the liquid crystal meter) with this device, together with changes in the external light amount (outdoor brightness). When not in use, Fig. 5 shows the case where meter indoor lighting is used, Fig. 6 is a block system diagram showing another embodiment of the present invention, and Fig. 7 shows this other embodiment in more detail. The circuit diagrams shown in Figures 8 and 9 show changes in the amount of light inside the meter room as well as changes in the amount of external light when a conventional daylighting device is applied to the daylighting window of a liquid crystal display meter that uses outside light. FIG. 8 is a diagram showing the change in light amount when the metered indoor lighting is not used, and FIG. 9 is a diagram showing the change in light amount when the metered indoor lighting is used, with the vertical axis representing the light amount and the horizontal axis representing time. In the drawing, (1) is an external light amount sensor, (2) is a lighting window, (3) is an internal light amount sensor, (5) is a comparison circuit, and (6) is an internal light amount sensor.
) is a driving means, and (7) is a shutter means. Patent applicant: Honda Motor Co., Ltd. Representative: Patent attorney (Part 2)
Patent Attorney: Kuni Ohashi, Patent Attorney: Udomo Koyama, Patent Attorney: No.
1) Shigeru Figure 1 To Figure 3 Figure 4 Figure 5 Question

Claims (1)

[Claims] A lighting device comprising a shutter means for blocking light in a lighting window that separates a room from the outside, comprising: an external light amount sensor installed outside the lighting window to detect the brightness of the outside; an internal light amount sensor that detects indoor brightness; a comparison circuit that compares output signals of the external light amount sensor and the internal light amount sensor; A lighting device for a vehicle meter, comprising: a drive means for driving the shutter means.