JPH07266924A - Display device of vehicle - Google Patents

Abstract

PURPOSE:To provide a display device of a vehicle capable of easily detecting fouling on a front glass such as clouding, etc. CONSTITUTION:A display device of a vehicle to display a display image by projecting information on a display region setting light having specified light components on a front glass 2 from a light source 6 has a background luminance detection means 12 to detect background luminance, a display means 8 to display information by display luminance by way of setting the display luminance in accordance with this detected value of the background luminance, a reflection detection means 12 to detect reflection from the front glass 2 and a fouling detection means to detect fouling of the front glass from a detection state of the light components of the light source detected by this reflection detection means 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle display device, and more particularly to a vehicle display device in which a display area is set on a windshield in front of a passenger compartment and information is displayed in the display area.

[0002]

2. Description of the Related Art Conventionally, as a display device for a vehicle such as an automobile, a display area is set on a windshield of a vehicle for the purpose of improving visibility when a driver views the display while driving. A so-called head-up display device is generally known in which information to be displayed is displayed as a display image projected on the windshield. By adopting such a type of display device, the amount of movement of the line of sight when the driver viewing the front through the windshield visually recognizes the display information while driving the vehicle is fitted into a predetermined position in the instrument panel. Compared with the conventional type of display device (meter display device), it is much smaller than the conventional display device, which improves visibility and allows you to check the displayed information while looking at the front field of view. Can be increased. Further, as a display device of this type, Japanese Patent Application Laid-Open No. 3-90439 discloses a display device in which the display brightness of a head-up display device is changed according to the background brightness.

[0003]

In the vehicle display device which is the above-mentioned head-up display device, when the vehicle is in a normal traveling state, the driver can simultaneously confirm the display information on the windshield while looking at the front view. Therefore, it is extremely effective in improving safety during driving.
On the other hand, when the temperature difference between the inside and outside of the vehicle is large or the humidity is high, the inner surface of the windshield becomes cloudy due to water droplets or the like. The fog on the inner surface of the windshield is fatal to the head-up display device and causes a problem that the display becomes invisible. Moreover, if dust is accumulated on the protective glass of the head-up display device or if an obstacle such as a map is placed on the head-up display device, the display by the head-up display device cannot be seen. Therefore, the present invention has been made to solve the drawbacks of the conventional techniques, and an object of the present invention is to provide a display device for a vehicle that can easily detect dirt such as fogging on the windshield.

It is another object of the present invention to provide a display device for a vehicle which can easily detect an obstacle placed above the device. Still another object of the present invention is to provide a display device for a vehicle capable of detecting dirt on a windshield and automatically preventing the dirt.

[0005]

In order to achieve the above object, the present invention projects light having a predetermined light component from a light source onto a display area set on a windshield to display information thereon. In a display device of a vehicle for displaying, a background brightness detecting means for detecting background brightness, a display means for setting display brightness according to a value of the detected background brightness, and displaying information by the display brightness, and a windshield. It is characterized by having a reflection detecting means for detecting the reflection from and a dirt detecting means for detecting the dirt on the windshield according to the detected state of the light component of the light source detected by the reflection detecting means. In the present invention thus configured,
The reflection detecting means detects the reflection from the windshield, and the dirt detecting means detects the dirt on the windshield according to the detected state of the detected light component of the light source. As a result, the problem of stains on the windshield can be easily detected. Further, in the vehicle display device according to the present invention, it is preferable that the reflection detecting means detects diffuse reflection caused by fogging. Further, in the vehicle display device of the present invention, the reflection detection means is
It is preferable that it also serves as the background luminance detecting means.

Further, the vehicle display device according to the present invention further comprises a stain preventing means which automatically operates to prevent the stain when the stain detecting means detects stain on the windshield. It has a feature. Therefore, according to the vehicle display device of the present invention, it is possible to detect the stain on the windshield and automatically prevent the stain. Further, the present invention is a display device of a vehicle, which displays information by projecting light having a predetermined light component from a light source onto a display area set on a windshield to display a background image. Detecting means, display means for setting display brightness according to the value of the detected background brightness and displaying information by this display brightness, and detection of reflection from the obstacle when there is an obstacle on the display means Reflection detecting means, and an obstacle detecting means for detecting the obstacle by the detection state of the light component of the light source detected by the reflection detecting means,
It is characterized by having. In the present invention thus constituted, the obstacle is detected by the reflection detecting means, and the obstacle is detected based on the detected state of the light component of the detected light source. As a result, if there is an obstacle on the display means, this obstacle can be easily detected.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle display device of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram showing an embodiment of a vehicle display device of the present invention. In FIG. 1, reference numeral 1 denotes the entire head-up display device, and the head-up display device 1 is configured as follows. First, a thin-film combiner 4 that forms a display area is formed on the indoor side surface of the windshield 2 of the vehicle. 6 is a light source, and a display 8 is provided in front of the light source 6. The display 8 sets a plurality of patterns of driving information to be displayed, such as the vehicle speed and the distance to the preceding vehicle. 10
Is a reflection mirror for reflecting the light from the light source 6 that has passed through the display 8 at a predetermined angle on its reflection surface. Reference numeral 12 is an optical sensor for detecting background brightness and diffused reflection described later. A protective glass 13 is provided on the upper part of the device. The display light of the driving information displayed on the display 8 is reflected by the reflection mirror 10 and projected on a predetermined area of the combiner 4 of the windshield 1 to display the driving information.

As a result, the driver seated in the driver's seat has its eye range (the range of movement of the driver's eye position).
The display image, which is an upright virtual image of the information, is formed from 14 on the outside front position of the windshield 1 by the display light of the driving information displayed on the combiner 4.
It can be seen by overlapping with the scenery in front of. By providing such a head-up display device, when a driver who is looking forward through the windshield 1 visually recognizes driving information while driving the vehicle, a display device that displays this information is displayed at a predetermined location in the instrument panel. Compared with the conventional type that was embedded in the driver, the amount of movement of the driver's line of sight will be smaller, visibility will be improved, and the displayed driving information can be checked while looking at the front view. The safety when driving the vehicle is improved. FIG. 2 is a diagram showing a state in which water droplets 16 are attached to the combiner 4 of the windshield 2 and diffuse reflection is caused by the combiner 4. FIG. 3 is a diagram showing a state in which the obstacle 18 is placed on the head-up display device 1. The output state of the optical sensor 12 in the states of FIGS. 2 and 3 will be described with reference to FIG. In FIG. 4, A is
The output state of the optical sensor 12 in a normal state where there are no water droplets 16 on the combiner 4 of the windshield 2 and no obstacle 18 on the head-up display device 1 is shown, and the optical sensor 12 outputs only the optical component of the outside world. is doing. On the other hand, B
Indicates the output state of the optical sensor 12 when water droplets 16 are attached to the combiner 4 of the windshield 2 and causing irregular reflection. The optical sensor 12 indicates the output component of the head-up display device due to external light and irregular reflection. The composite value of is output. This output value contains a specific frequency component that indicates diffuse reflection.

Further, C is the optical sensor 12 with the obstacle 18 placed on the head-up display device 1.
The optical sensor 12 outputs only the output component of the head-up display device due to diffused reflection. This output value consists only of a specific frequency component that indicates diffuse reflection. FIG. 5 is a flowchart showing the control contents according to the embodiment of the present invention. In FIG. 5, S represents each step. As shown in FIG.
First, in S1, the output signal from the optical sensor is input. Next, in S2, it is determined whether or not the output signal has a specific frequency component indicating that the light component of the light source is irregularly reflected (see FIG. 4). If YES, the process proceeds to S4, and it is determined that the windshield is cloudy or there is an obstacle. Next, at S, the defroster is activated, an alarm is issued, and / or the display brightness is increased. If NO in S2, the process proceeds to S5, and the display brightness of the head-up display device is adjusted so as to have a predetermined contrast ratio based on the background brightness detected by the optical sensor. Next, the operation of the above embodiment will be described. In a normal case, the display brightness of the head-up display device is set based on the background brightness so as to have a predetermined contrast ratio (display brightness / background brightness) with the background brightness. This background brightness is detected by the optical sensor 12.

On the other hand, as described above, the windshield 2
Cloudy combiner 4 with water droplets 16 on combiner 4
In the case where the diffuse reflection is caused in the head up display device or the obstacle 18 is placed on the head-up display device 1, the existing light sensor 12 is used to detect the light component of the light source from the front. Fogging of glass and obstacles can be detected very easily. Further, when the windshield is clouded or an obstacle is detected, such an undesired state can be easily solved by operating the defroster, issuing an alarm, and / or increasing the display brightness.

[0011]

As described above, according to the vehicle display device of the present invention, it is possible to easily detect dirt such as fogging on the windshield.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a vehicle display device of the present invention.

[Fig. 2] Shows a state where water drops are attached to the windshield to cause diffuse reflection.

FIG. 3 is a diagram showing a state in which an obstacle is placed on the device.

FIG. 4 is a diagram showing an output state of the optical sensor in the states of FIGS. 2 and 3.

FIG. 5 is a flowchart showing the control contents according to the embodiment of the vehicle display device of the present invention.

[Explanation of symbols]

 1 Head-up display device 2 Windshield 4 Combiner 6 Light source 8 Display 10 Reflecting mirror 12 Optical sensor 13 Protective glass 16 Water drop 18 Obstacle

Claims (5)

[Claims] 1. In a display device of a vehicle for projecting information having a predetermined light component from a light source onto a display area set on a windshield to display the display image, background brightness detection for detecting background brightness. Means, display means for setting display brightness according to the detected background brightness value and displaying information by this display brightness, reflection detection means for detecting reflection from the windshield, and this reflection detection means A display device for a vehicle, comprising: a dirt detection unit that detects dirt on a windshield based on a detected state of a light component of the light source. 2. The reflection detecting means detects irregular reflection caused by fogging.
The vehicle display device described. 3. The vehicle display device according to claim 1, wherein the reflection detecting means also serves as the background luminance detecting means. 4. The method according to claim 1, further comprising a stain prevention unit that automatically operates to prevent the stain when the stain detection unit detects stain on the windshield. The display device for a vehicle according to any one of 3 above. 5. A background luminance detection for detecting background luminance in a vehicle display device for projecting information having a predetermined light component from a light source onto a display area set on a windshield to display the display image. Means, display means for setting display brightness according to the value of the detected background brightness, and displaying information by this display brightness, and detection of reflection from the obstacle when there is an obstacle on the display means. A display device for a vehicle, comprising: a reflection detecting unit; and an obstacle detecting unit that detects the obstacle based on a detection state of a light component of a light source detected by the reflection detecting unit.