JP2008137546A - In-cabin lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-cabin lighting system capable of realizing illuminance of an adequate value in a cabin. <P>SOLUTION: The in-cabin lighting system comprises a road surface brightness detection means for detecting the road surface brightness which is at least a part of the brightness in a range to be lit by a headlamp on the road surface, and an illuminance sensor 5 for detecting the illuminance in the cabin. The light output of a cabin light 1 is controlled so that the illuminance detected by the illuminance sensor 5 is determined according to the road surface brightness, and the higher the road surface brightness is, the higher the target illuminance is. The target illuminance is set to be ≥10 lux when the target illuminance is lower than the illuminance corresponding to the road surface brightness, and the road surface brightness is 10 cd/m<SP>2</SP>. The illuminance in the cabin can be set to an adequate value in comparison with the case in which the target illuminance is higher than the illuminance corresponding to the road surface brightness, or a case in which the target illuminance is <10 lux when the road surface brightness is 10 cd/m<SP>2</SP>. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an in-vehicle lighting system.

  At night, when the passenger compartment is dark with respect to the brightness of the road illuminated by the headlights, when the driver's eyes are lightly adapted to the brightness of the road, the operation panel and floor surface of the passenger compartment, such as sound and air conditioning It takes time to darkly adapt to the brightness of the operation panel and the floor surface.

In order to shorten or eliminate such dark adaptation time, an in-vehicle illumination system has been proposed in which the illuminance in the passenger compartment is increased according to the road surface brightness (see, for example, Patent Document 1).
JP-A-3-28034

  In the interior lighting system as described above, it is important how to adjust the light output of the interior lamp with respect to the road surface luminance.

  This invention is made | formed in view of the said reason, The objective is to provide the illumination system for vehicle interior which can make the illumination intensity of a vehicle interior into a more appropriate value.

The invention of claim 1 is a road surface luminance detecting means for detecting a road surface luminance that is at least part of a range illuminated by a headlamp on the road surface, an interior lamp that is dimmable and illuminates the interior of the vehicle, The interior light lighting means for supplying power to the interior light to light it, the interior illumination detection means for detecting the illumination intensity of at least part of the range illuminated by the interior light in the interior of the vehicle, and the illuminance detected by the interior illumination detection means The interior light control for controlling the interior light lighting means to increase / decrease the power supplied to the interior light so that the higher the road surface brightness is, the higher the target illuminance is determined according to the road surface brightness detected by the road surface brightness detecting means. And a target illuminance is lower than an illuminance corresponding to the road surface luminance, and is 10 lux or more when the road surface luminance is 10 cd / m ² .

According to the present invention, the illuminance in the passenger compartment can be reduced as compared with the case where the target illuminance is higher than the illuminance corresponding to the road surface brightness, or when the target illuminance is less than 10 lux when the road surface brightness is 10 cd / m ^2. It can be set to an appropriate value.

  According to a second aspect of the present invention, in the first aspect of the invention, the road surface luminance detecting means is an image pickup means for picking up an image of the front of the vehicle, and a range in which the image picked up by the image pickup means is processed and illuminated by the headlamp. The in-vehicle illumination system according to claim 1, further comprising: an extracting unit that extracts a road surface luminance; and a luminance calculating unit that calculates a road surface luminance based on a luminance of a pixel included in a range extracted by the extracting unit.

  According to the present invention, the imaging means can be used for both obstacle detection and operation recording.

According to the present invention, since the target illuminance is lower than the illuminance corresponding to the road surface luminance and 10 lux or more when the road surface luminance is 10 cd / m ² , the target illuminance is set higher than the illuminance corresponding to the road surface luminance. Compared with the case where the target illuminance is set to less than 10 lux when the road surface brightness is 10 cd / m ² , the vehicle interior illuminance can be set to an appropriate value.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  In the present embodiment, as shown in FIG. 2, the interior lamp 1 (see FIG. 1), the interior lamp lighting section 2 that supplies power to the interior lamp 1 and lights it, and the interior lamp lighting section 2 are replaced by the interior lamp 1. An interior light control unit 3 that controls the light output of the interior light 1 by controlling the power supplied is provided. Moreover, the road surface brightness | luminance detection part 4 which detects the road surface brightness | luminance which is the brightness | luminance of at least one part of the area | region illuminated with the headlamp, and the illumination intensity sensor 5 which detects the illumination intensity in a vehicle interior are provided. The interior lamp control unit 3 controls the interior lamp lighting unit 2 so that the illuminance detected by the illuminance sensor 5 becomes the target illuminance determined according to the road surface brightness detected by the road surface brightness detection unit 4. That is, the interior light control unit 3 compares the illuminance detected by the illuminance sensor 5 with the target illuminance, and the electric power supplied to the interior light 1 when the illuminance detected by the illuminance sensor 5 is lower than the target illuminance. When the illuminance detected by the illuminance sensor 5 is higher than the target illuminance, the electric power supplied to the interior lamp 1 is decreased.

  The road surface luminance detection unit 4 is composed of, for example, a CCD (Charge Coupled Device) camera, and an imaging unit 41 that images the front of the vehicle C (see FIG. 1), and is illuminated by a headlamp from an image captured by the imaging unit 41 The image processing unit 42 is an extraction unit that extracts a region, and a luminance calculation unit 43 that calculates the road surface luminance based on the average luminance value of pixels included in the range extracted by the image processing unit 42. The image picked up by the image pickup unit 41 can be used, for example, for obstacle detection using a well-known image processing technique and driving recording. Since the image processing unit 42 and the luminance calculation unit 43 can be realized by a known technique, a detailed description thereof is omitted.

  The illuminance sensor 5 is placed on a dashboard, for example. In addition, the image processing unit 42, the luminance calculation unit 43, the interior lamp lighting unit 2, and the interior lamp control unit 3 are housed in a common body CB and placed, for example, on the floor in the vehicle interior.

  The interior lamp 1 has a configuration shown in FIGS. 3A to 3D, for example. The interior lamp 1 has a rear surface of the front mirror or a rear side of the sun visor, with the upper surface of FIG. 3B facing the ceiling surface of the passenger compartment and the upper portion of FIG. Mounted on the ceiling of the passenger compartment. Hereinafter, the top, bottom, left, and right are based on FIG. 3B, and the top of FIG. In addition, the left half of Fig.3 (a) is a bottom view of the interior lamp 1, and the right half is a bottom view which removed the cover 12 mentioned later. Further, the left half of FIG. 3B is a front view of the interior lamp 1, and the right half is a cross-sectional view.

  More specifically, the interior lamp 1 includes a housing 10 including a body 11 having a concave portion 11a that opens downward, and a cover 12 that is coupled to the body 11 and covers the concave portion 11a. In the body 11, a screw hole 11 b is vertically penetrated in the bottom surface of the recess 11 a, and the body 11 is screwed and fixed to the ceiling material CE of the passenger compartment by a screw (not shown) inserted through the screw hole 11 b. .

  A first light source block 13 having a printed wiring board 13b in which two disk-shaped light emitting diodes 13a are arranged in the front and rear and are mounted with the light emitting portions facing downward is attached to the central portion of the body 11 in the left-right direction. ing. Further, a cylindrical reflecting plate 13c surrounding the light emitting diode 13a when viewed from the front is screwed and fixed to the body 11 below the printed wiring board 13b. The inner surface of the reflecting plate 13c has an inverted truncated pyramid shape in which the inner surface is inclined outwardly downward, and the inner surface of the reflecting plate 13c distributes the light of the light emitting diode 13a.

  In addition, three second light source blocks 14 are arranged vertically at both left and right ends of the housing 10. As shown in FIGS. 4A and 4B, each second light source block 14 is formed by attaching a holder 14b to a light emitting device 14a having a light emitting diode (not shown) as a light source. The left half of FIG. 4A is a front view, and the right half is a front view of the holder 14b cut away. 4B is a bottom view of the second light source block 14, and the right half is a plan view. The holder 14b of each second light source block 14 is supported with respect to the body 11 by a support portion 11c (not shown in FIG. 3A) projecting below the body 11, respectively. It is supported so as to be rotatable in the plane. That is, the light distribution can be changed by rotating the second light source block 14 with respect to the body 11.

  Further, on the front side of the printed wiring board 13b, two third light source blocks 15 each having a light-emitting diode (not shown) as a light source are respectively provided in front by a support plate 16 protruding downward from the body 11. It is fixed in the direction to illuminate the operation panel diagonally below.

  The body 11 is provided with a through hole 11d through which an electric wire (not shown) for supplying power to each light emitting diode is inserted.

  Furthermore, the left and right ends of the lower surface of the cover 12 are inclined downward toward the center in the left-right direction. A central portion of the lower surface of the cover 12 in the left-right direction is made of a light-transmitting material, a first diffusion portion 12a that diffuses light from the third light source block 15, and a light-transmitting material. A second diffusion part 12b for diffusing the light of the light source block 13 is provided side by side. Further, at the left and right end portions of the lower surface of the cover 12, three window portions 12 c made of a light-transmitting material and transmitting the light of the left and right second light source blocks 14 are arranged vertically.

  Further, a push button switch 17 is provided below the lower window portion 12c. As shown in FIG. 5, the push button switch 17 is exposed to the lower side of the cover 12 and can be displaced up and down with respect to the cover 12. The push button switch 17 is fixed to the upper surface of the cover 12 and is connected to the push button handle 17a. And a main body portion 17b in which a contact (not shown) that switches on and off when the handle 17a is pushed upward is housed. The contact point of the push button switch 17 is inserted in the power supply path to the light emitting diodes of the light source blocks 13, 14, and 15, and the interior lamp 1 can be switched on and off by pushing the push button handle 17a. The structure of the interior lamp 1 is symmetrical except for the push button switch 17.

  By the way, the present inventor investigates the relationship between the time taken to adjust the darkness by moving the line of sight to the operation panel from the state of being brightly adapted to the brightness of the road surface illuminated by the headlamp and the illuminance of the operation panel. We are conducting an experiment.

  That is, the subject first adjusts lightly by staring at the screen of the CRT monitor for 1 minute, and then looks at the test panel illuminated with a predetermined illuminance by the LED illumination. That is, the screen of the CRT monitor imitates the road surface illuminated by the headlight, and the test panel imitates the operation panel in the vehicle interior.

The luminance of the CRT monitor screen was 10 cd / m ² and the color of the CRT monitor screen was white. The distance between the subject and the CRT monitor was 2 m, and the distance between the subject and the test panel was 1 m.

  A Landolt ring was drawn on the test panel, and the time from when the subject moved to the test panel until it responded to the direction of the Landolt ring was measured. Then, the above measurement is performed five times for each of the eight test subjects each having a visual acuity of 0.5 for the illuminance of the test panel of 5 lux, 10 lux, 15 lux, 20 lux, and 25 lux. went. 6A and 6B are graphs in which the average value for five times is taken on the vertical axis and the illuminance of the test panel is taken on the horizontal axis. 6 (a) and 6 (b), different broken lines L1 to L6 show the results of different subjects. Moreover, the broken line L7 of FIG.6 (b) shows the average value for a total of eight persons of six persons shown by the broken lines L1-L6 and two persons which are not shown in figure.

As a result of the above-described experiment, the time taken for the response is shortened most between 5 lux and 10 lux in any subject. That is, when the road surface brightness is 10 cd / m ^2, it can be said that the illuminance in the passenger compartment is appropriate to be 10 lux or more.

Based on the above experimental results, in this embodiment, the target illuminance when the road surface brightness is 10 cd / m ² is set to 10 lux or more.

  In addition, in order to reduce or eliminate the time required for dark adaptation when the line of sight is moved from the road surface illuminated by the headlamps to the operation panel in the passenger compartment, it is necessary to make the operation panel brightness higher than the road surface brightness. Therefore, in this embodiment, the target illuminance is made lower than the numerical value obtained by dividing the road surface brightness by the illuminance at which the brightness of the operation panel is the same as the road surface brightness, that is, the reflectance of the material occupying most of the surface area of the operation panel. Yes. That is, the above numerical value as the upper limit of the target illuminance is “illuminance corresponding to road surface luminance” in claim 1.

According to the above configuration, the target illuminance is set to 10 when the target illuminance is higher than the illuminance at which the luminance of the operation panel in the vehicle becomes the luminance detected by the road surface luminance detecting means, or when the road surface luminance is 10 cd / m ^2. Compared with the case where it is less than lux, the illuminance in the passenger compartment can be set to an appropriate value.

  The upper limit value of the target illuminance is not limited to the above value. For example, in order to shorten or eliminate the time required for dark adaptation when the line of sight is moved from the road surface illuminated by the headlight to the floor surface in the vehicle interior, the reflection of the operation panel is used to calculate the upper limit of the target illuminance. Instead of the rate, the reflectance of the floor surface may be used.

It is explanatory drawing which shows the structure of this invention. It is a block diagram which shows the same as the above. (A)-(d) is a figure which shows the interior lamp in each same, (a) The left half is a bottom view, The right half is a bottom view which removed the cover, The left half of (b) It is a front view, the right half is a sectional view, (c) is a plan view showing the main part, and (d) is a sectional view. (A) (b) is a figure which shows the spotlight used for the interior lamp of FIG. 3, respectively, The left half of (a) is a front view, The right half is a front view which fractured | ruptured the holder, (b ) Is a bottom view, and the right half is a plan view. It is sectional drawing which shows the pushbutton switch vicinity in the interior lamp of FIG. (A) (b) is explanatory drawing which shows the result of the experiment which this inventor performed, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Interior light 2 Interior light lighting part 3 Interior light control part 4 Road surface brightness | luminance detection part 5 Illuminance sensor 41 Imaging part 42 Image processing part 43 Luminance calculation part

Claims (2)

Road surface brightness detecting means for detecting road surface brightness that is at least part of the brightness of the range illuminated by the headlamps on the road surface;
An interior light that is dimmable and illuminates the interior of the vehicle,
Interior light lighting means for supplying power to the interior light and lighting it,
In-vehicle illuminance detection means for detecting the illuminance of at least part of the range illuminated by the interior light in the vehicle,
By controlling the interior lamp lighting means so that the illuminance detected by the interior illuminance detection means is determined according to the road surface brightness detected by the road surface brightness detection means and becomes higher as the road surface brightness is higher, An interior light control means for increasing or decreasing the supplied power,
The in-vehicle illumination system characterized in that the target illuminance is lower than the illuminance corresponding to the road surface brightness and is 10 lux or more when the road surface brightness is 10 cd / m ² . The road surface brightness detection means
Imaging means for imaging the front of the vehicle;
An extraction unit that performs image processing on an image captured by the imaging unit and extracts a range illuminated by the headlamp;
The in-vehicle illumination system according to claim 1, further comprising: a luminance calculation unit that calculates road luminance based on the luminance of pixels included in the range extracted by the extraction unit.

Images