JPH06144081A - Head-up display unit equipped with automatic dimming function for vehicle - Google Patents

Abstract

PURPOSE:To form an automatic dimming function excellent in reliability by integratedly installing a photosensor and a photosensor drive circuit in the lower part of a projector and also a photoconductor conducting an external light up to the photosensor, respectively. CONSTITUTION:A photosensor 11 for regulating the luminance of an indicator according to external brightness and its drive circuit 10 both are solidly installed together with a projector 16 of a head-up display unit. With this projector 16 attached to a car body, the photosensor 11 is also installed in the car body in consequence, so that assembling work of this head-up display unit equipped with an automatic dimming function to the car body is sharply improved. In addition, as a light receiving means for the photosensor 11, a photoconductor 14 is used for the end. Any direct light is not irradiated to the photosensor 11, therefore this photosensor 11 receives no temperature change due to direct projection, and thereby a charactersitic of the photosensor 11 is nor varied at all, whereby automatic dimming excellent in reliability is performable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-up display device having a vehicle automatic light control function.

[0002]

2. Description of the Related Art As a conventional head-up display device having such a vehicle automatic light control function, there is one shown in FIGS. 1 and 2, for example. This is provided with a main body case 3 having an opening 2 on the upper surface inside an instrument panel 1 provided in front of a driver's seat, and inside the main body case 3, a sub-display 4 using a fluorescent display tube. And a plane mirror 5 for reflecting the display image from the sub-display 4 is arranged, and a transparent cover 6 for preventing dust from entering the body case 3 is provided in the opening 2. The projector 16 is formed. Further, a translucent reflector (combiner) 8 serving as a half mirror is provided on the inner surface of the windshield 7 located above the instrument panel 1 so that the display image of the sub-display 4 is transmitted to the plane mirror 5 and the translucent light. The image is displayed on the display 4 together with the scene in front of the vehicle after the light is reflected by the reflective reflector 8.

The defroster prevents the display itself from being visually recognizable by the projector 16 due to changes in the brightness of the background of the display portion, such as being too bright and dazzling, being too dark to see, and being difficult to see in the evening double image. The light sensor 11 arranged in the garnish 13 is used to detect the brightness of external light, and the light is automatically adjusted to keep the ratio of the display brightness and the external light constant according to the detected output. Has been done.

Reference numeral 9 denotes a main display, for example, of an analog type or a digital type, which is installed inside the instrument panel 1 and displays vehicle speed, engine speed, etc., and 15 shows the main display 9 and the sub-display. 4 is a display controller for driving 4, and 17 is the sub-display and the main display 4, 9
10 is a sensor for driving the optical sensor drive circuit.

[0005]

However, in such a conventional head-up display device having an automatic light control function for a vehicle, the light used in the head-up display device having the automatic light control function is used. Sensor 11
Since the display brightness must be changed depending on the brightness of the external light even in the daytime, highly accurate photometry is required. As a result, the photosensor drive circuit 10 having a complicated circuit is used, or the cost is high. A precision head-up display optical sensor 11 must be used.

However, in the conventional head-up display device having the automatic light control function, the optical sensor 11 is attached to the surface of the defroster garnish 13 attached to the upper surface of the instrument panel 1, for example. Since it is arranged at a position where it is easy to receive external light, its optical sensor is likely to receive direct light, and the characteristics of this optical sensor 11 are likely to change due to temperature changes due to external heat, etc. As a result, there is a problem in that the accuracy of external light measurement is reduced.

Further, in the prior art, since the optical sensor 11 is installed separately from the projector 16 in the instrument panel, it takes a lot of time and labor to install the projector 16 and the optical sensor 11 and to connect the circuits, and the assembling workability is improved. There were also problems such as poor economy.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and an optical sensor is integrally attached to a lower portion of a projector of a head-up display device so that the optical sensor is mounted at the same time when the projector is mounted on a vehicle body. Is completed to improve the workability of assembling the head-up display device with the automatic light control function. In addition, the light sensor mounted on the bottom of the projector uses a light guide to receive external light, and this light guide suppresses the heat receiving action of the light sensor, and changes the characteristics of the light sensor due to heat. It is an object of the present invention to provide a head-up display device having an automatic dimming function that can prevent and maintain a highly accurate optical sensor.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. The same parts as those of the structure of this embodiment and those of the conventional example are designated by the same reference numerals as those of the conventional example. The description of the same structure part is omitted.

That is, an optical sensor unit in which the optical sensor 11 and the optical sensor drive circuit 10 are integrated is arranged under the main body case 3 of the projector 16 and is integrally equipped with the projector 16 via a mounting member 20. Case 3
As a means for causing the optical sensor 11 arranged at the lower portion to receive external light, a light guide 14 made of a heat-resistant acrylic material is provided, the light receiving end of which projects on the instrument panel 1 (from the surface of the finisher 12). The optical sensor 11 receives light.

Head-up display finisher 12
As shown in FIG. 5, the light-receiving end portion of the light guide body 14 slightly protruding from the surface has a truncated cone shape, and the surface of the light-receiving end portion is satin-finished to prevent surface reflection. Further, the heat-resistant acrylic material, which is transparent for the light guide body 14, has a smoked color that does not change the wavelength of the guided external light because it is reflected in a window at night.

The structure of this embodiment has been described above. Next, the operation thereof will be described. In FIG. 3, the display light emitted from the display 4 by the fluorescent display tube passes through the representative optical path b and is reflected by the plane mirror 5. The optical path is bent and passes through the representative optical path a.
The display light passing through the representative optical path a is incident on a point P on the inner surface of the windshield 7, is reflected by the translucent reflector 8 and is displayed by the indicator 4 together with the scene in front of the vehicle by the translucent reflector 8. The image can be read.

Further, the head-up display finisher 1 is provided so that it is not difficult to visually recognize a display image on the display 4.
2 External light is taken in from the light receiving end of the light guide 14 slightly protruding from the surface 2 and guided to the optical sensor 11 mounted on the lower part of the projector 16 to detect the brightness of the external light. The display controller 15 is driven by the detection signal of 11, and the automatic dimming control of the display device 4 is performed so as to keep the ratio of the display brightness and the external light constant according to the detection output.

Therefore, according to the present embodiment, the optical sensor 11 for adjusting the brightness of the display according to the external brightness and the drive circuit 10 thereof are provided integrally with the projector 16 of the head-up display device. Therefore, by mounting the projector 16 on the vehicle body, the optical sensor 11 is also installed on the vehicle body, and the work of assembling the head-up display device having the automatic light control function on the vehicle body is significantly improved. Further, since the light guide 14 is used as a light receiving means for the optical sensor 11, the optical sensor 1
1 is not exposed to direct light, and therefore the optical sensor 1
1 does not undergo a temperature change due to direct radiation, the characteristics of the optical sensor 11 do not change due to this, and highly reliable automatic light control is performed.

[0015]

As described above, according to the present invention, the information display such as characters and figures is reflected by the windshield 7 of the vehicle or the translucent reflection plate 8 provided in front of the windshield to display a virtual image in front of the windshield. In a head-up display device equipped with a projector 16 for projecting an image in the instrument panel 1 and having an automatic light control function for displaying the information in superposition with the scenery of the outside world, the optical sensor 11 and the optical sensor drive circuit 10 are provided. Since the head-up display device is provided integrally with the lower part of the projector 16 and the light guide body 14 for guiding the external light to the optical sensor 11, the brightness of the display is adjusted according to the external brightness. Sensor 11 and its drive circuit 1 for adjusting
0 is the projector 1 of the head-up display device
Since it is integrally provided with the projector 6, the optical sensor 11 is also installed in the vehicle body by mounting the projector 16 on the vehicle body, and the work of assembling the head-up display device having the automatic light control function to the vehicle body is greatly performed. Will be improved.
Further, since the light guide 14 is used as a light receiving means for the optical sensor 11, the optical sensor 11 is not irradiated with direct light, and therefore the optical sensor 11 may be subjected to temperature change due to direct irradiation. Without this, the optical sensor 1
The characteristic of No. 1 does not change, and the effect is obtained that automatic dimming with excellent reliability is performed.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a conventional head-up display device.

FIG. 2 is an explanatory diagram of an external structure of an instrument panel unit of a conventional example.

FIG. 3 is a structural explanatory view of a head-up display device according to an embodiment of the present invention.

FIG. 4 is an explanatory view of the external structure of the instrument panel portion of the embodiment of the present invention.

FIG. 5 is an explanatory view of a main part structure of the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Instrument panel 2 ... Opening 3 ... Main body case 4 ... Sub-display 5 ... Plane mirror 6 ... Transparent cover 7 ... Windshield 8 ... Translucent reflector 9 ... Main display 10 ... Optical sensor drive circuit 11 ... Optical Sensor 12 ... Display finisher 13 ... Defroster garnish 14 ... Light guide 15 ... Display controller 16 ... Projector 17 ... Sensor

Claims (1)

[Claims] 1. A projector for projecting a virtual image display image in front of a windshield (7) of a vehicle or a translucent reflector (8) provided in front of the windshield to reflect information such as characters and figures. In a head-up display device having (16) in an instrument panel (1) and having an automatic light control function for displaying the information by superimposing it on the scenery of the outside world, an optical sensor (11) and an optical sensor drive circuit ( 10) is integrally provided under the projector (16), and external light is emitted from the optical sensor (1).
A head-up display device having an automatic light control function, which is provided with a light guide (14) for leading to 1).