JPS6320243A - Head-up display device for vehicle - Google Patents

Abstract

PURPOSE:To reduce the weight of a HUD unit, by providing an incident light detecting half mirror function and an optical shutter function concurrently for an external light such as the sunlight. CONSTITUTION:Between a display element 42 and an optical lens 46, a reflection plate 52 is furnished, and an optical shutter 54 is furnished in front of the display element 42 between the element 42 and a half mirror 50. The half mirror 50 and the optical shutter 54 are controlled by a controller 58 including a shutter switching control circuit 62. When the sunlight is on the extension line of the optical axis of the optical lens 46, the light passing through the optical lens 46 is converted its passing direction by the reflection plate 52, and injected to the half mirror 50. A part of the incident light is reflected in the direction almost 90 deg. to the half mirror 50 surface, and detected by a detection sensor 48. And a photoelectric current proportional to the quantity of light is generated at the detection sensor 48.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a head-up display device for a vehicle, and particularly to a head-up display device (hereinafter referred to as 1'1lUI).
This is a display system for vehicles that projects the display image from units 1 to 1 on the fluorocarbon glass.

[Prior art] In a vehicle, current vehicle speed, fuel consumption, traveling v]]1l
II? A display device is installed to display 7, and is used as a head-up display device that projects the display image from the HtJ I) unit onto the windshield and allows the driver to recognize the display image.

As such a head-up display device, the technology described in Japanese Utility Model Application No. 1987-195706 filed by the present applicant is known.

FIG. 8 shows its schematic configuration, in which an i"UD unit 1 is installed inside the instrument panel 10, which has a curved inner surface.
12 is written as the setting number. This point (UD: 1 nit 1
Reference numeral 2 denotes a display element 16 that displays various driving conditions by light irradiation from the illumination lamp 14, an optical lens 22 that couples the displayed image by the display element 16 to the windshield 20 of the vehicle via a reflector 18, and the The display element 16 includes an optical shutter 1 footer 26 that blocks external light such as sunlight from entering the display element 16.

1J- That is, various running lines f using the optical lens 22.
1-]UD of the type that projects 1 onto the windshield 20
Units 1 ~ Odor, display element 1 due to reverse incidence of sunlight
The temperature of 6 is soil-like and there is a risk of deterioration.

As a countermeasure for this case, conventionally, an optical shutter 26 has been installed on the light incident path to block sunlight from entering.

A temperature sensor 24 is installed near the display element 16 to detect the temperature around the display element 16, and when the current detected temperature becomes higher than a preset temperature, The opening and closing of the optical shutter 26 was controlled by rollers 1 to 28.

In addition, other conventional examples (J: Utility Application No. 160976 of 1983 filed by the present applicant shown in FIG. 9) include an illumination lamp 114 similar to the above, and a display element 116.
, an optical shutter 126 and an optical lens 122 are arranged in this order, and a shielding pipe 30 placed around the optical lens 122 limits the angle of incidence of sunlight, and a photodiode 32 is installed inside the shielding pipe 30 to block the light from the lens 122. There was one in which several pieces were installed parallel to the axis.

The output from these diodes 32 is
4, the opening and closing of the optical shutter 126 was controlled.

[Problems to be Solved by the Invention] Conventional Problems However, in the first conventional technique, depending on the arrangement position of the temperature sensor 24, it takes time for the temperature sensor 24 to detect the screen above the scar. Therefore, it is difficult to quickly control the opening and closing of the shutter 26 in accordance with the change in the shutter 26.

Furthermore, in the second prior art described above, as shown in FIG. 10, a situation may occur in which sunlight only enters the optical lens 122 due to leaves or the like, but does not enter the photodiode 32. . Therefore, in this case, there was a problem in that the shutter 126 did not operate.

Purpose of the Invention The present invention has been made to solve the above problems, and provides a half mirror and an optical shutter, or a liquid crystal display having both of these functions, between a display means for displaying vehicle running conditions and an optical lens. The object of the present invention is to provide a capture device for a head-up display device for a vehicle in which burnout of a display element is prevented by providing a shutter.

[Means and Effects for Solving the Problems 1] In order to achieve the above object, the present invention provides display means for displaying various vehicle driving regulations by irradiation of light from a light projecting means, etc. an optical lens for forming an image on a vehicle window; a detection means for detecting external light incident on the display means; and a control for controlling the amount of external light incident when the amount of external light incident is equal to or greater than a predetermined value. a head-up display device for a vehicle, wherein the control means includes a half mirror and an optical shutter provided between the display means and an optical lens, and the control means includes a half mirror and an optical shutter provided between the display means and an optical lens, and the control means includes a half mirror and an optical shutter, and a part of the external light reflected by the half mirror. is detected by an external light detection sensor, and the opening/closing of the optical shutter is controlled according to the detected value.

In the above, sunlight is collected by an optical lens, a part of which is reflected by a half mirror, and the reflected light is detected and incident on an external light detection sensor.

In this external light detection sensor, a current proportional to the amount of incident light is generated, and this current is sent to the control unit to control opening and closing of the shutter, thereby preventing burnout of the display element when sunlight is incident.

Further, in the present invention, the control means includes a liquid crystal shutter provided between the display means and the optical lens, and an external light detection sensor detects a part of the external light reflected by the liquid crystal shutter. At the same time, the transmittance of the liquid crystal shutter is controlled according to the detected value.

The liquid crystal shutter uses a write-memory liquid crystal, and has the functions of a general optical half mirror and an optical shutter. Then, the frequency of the AC power applied to this liquid crystal is set to a low frequency (for example, 1001-I
When the liquid crystal is set to Z'), the liquid crystal becomes cloudy and the shutter shutter is closed, and the incident light does not pass through.If the applied AC power frequency is set to a high frequency (for example, 10K), the liquid crystal becomes transparent and the shirt shutter is open. By switching the frequency of the AC power supply in this manner, the opening and closing of the shutter can be controlled.

[Example] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

In FIG. 1, a 1-I U 1) size knit 38 is provided inside the panel 36 between the lumen 1 and the lumen 1 on the front surface of the vehicle interior, as described above.

This I-I U D unit 38 uses an illumination lamp 40 as a light projecting means to display a display liner 42 that displays the current vehicle speed, fuel r1, and various weighing conditions, and this display element 42. The displayed image is displayed on the vehicle's window glass 44.
an optical lens 46 that forms an image on the display element 42; a detection sensor 48 that detects incident light such as sunlight that enters the display element 42; 1-((J I)-1 days) of outside light ~3
A control means is provided for controlling the amount of light incident on the light source 8.

In this embodiment, a liquid crystal cell is used as the display element 42, and a photodiode is used as the detection sensor 48.

A feature of the present invention is that the control means includes a half mirror and an optical shutter provided between the display means and the optical lens.

That is, in this embodiment, a reflection plate 52 is provided between the display element 42 and the optical lens 46, and the optical shutter 54 is provided between the display element 42 and the half mirror 50 in front of the display element 42. These half mirrors 50 and optical shutters 54 are shutters TiVl'
It is controlled by a control unit 58 including a Zr 1ti11 m circuit 62.

The half mirror 50 is installed between the reflection plate 52 and the display element 42 in a direction inclined at approximately 45 degrees with respect to the incident light beam, and a part of the incident light beam is reflected by the half mirror 50, and the amount of light is It is detected by the detection sensor 48.

Further, the optical shutter 54 is driven to open and close by a motor 56.

In [below]-, when the sun is present on the optical axis of the optical lens 46, the optical path of the light passing through the optical lens 46 is changed by the reflecting plate 52 and enters the half mirror 50. A portion of this incident light is reflected in a direction of approximately 90 degrees to the surface of the half mirror 50 and is detected by the detection sensor 48. Then, at the detection sensor +j48, a photocurrent proportional to the amount of light is generated.

As shown in FIG. 2, this photocurrent is input to a comparator 60 of a shutter opening/closing control circuit 62, and the comparator 60 is connected to an AND circuit 66 and an amplifier circuit 68. The shutter opening/closing control circuit 62 is externally controlled by an L-IUD activation signal 64 used when projecting a display image onto the windshield 44, and thereby drives and controls the opening/closing motor 56 of the shutter 54. .

Then, the detection sensor/I8r determines whether or not there is a predetermined chain plate l-(゛) where the amount of incident light due to sunlight is set in advance. , a high level signal is output from the comparator 60 so that the output of the amplifier circuit 68 is turned off.

Therefore, even if an attempt is made to project a display image onto the windshield 44 when the incident light portion is greater than a predetermined value, the optical shutter 54 will not be opened.

FIG. 3 shows the relationship between the sunlight illuminance and the input voltage of the comparator 60, and as is clear from this figure, the input voltage of the comparator increases in proportion to the sunlight illuminance.

As described above, according to this embodiment, it is possible to effectively prevent burnout or deterioration of the display element 42 due to reverse incidence of sunlight.

In addition, the number of detection sensors 48, which were conventionally required in plurality, is reduced to one.
This detection sensor 48 is HLJ D
It can be easily installed in the unit 38, and therefore there is no need to provide a new installation hole in the instrument panel 36 for installing the sensor.

Second Embodiment A second embodiment of the present invention is shown in FIG. Element 142. When the amount of incident light detected by the optical lens 146 and the detection sensor 148 is greater than or equal to a predetermined value, the optical lens 146 is provided with a control means for controlling the input of external light into the unit 138. There is.

A characteristic feature of the present invention is that the control means includes display means 1
42 and an optical lens 146, a part of the external light reflected by the liquid crystal shutter 11 and the optical lens 146 is detected by the external light detection sensor 148, and the detected value is The transmittance of the liquid crystal screen 1/ivy 70 is controlled accordingly.

The liquid crystal shutter 70 uses a write-memory liquid crystal, and has both the function of a general optical half mirror and the function of an optical shutter.

5 to 7 show the operating principle of the liquid crystal shutter 70 in this embodiment.

In this liquid crystal shutter 70, a nenematic cholesteric mixed liquid crystal 76 is injected between glasses 72 and 74, and an electrode 78 is injected from inside the glasses 72 and 74.
a and 78b are taken out and connected to an AC power source 80 and a power switch 82.

The output frequency of the AC power supply 80 can be set in advance to two levels: 100H2 and 10KHz.

Then, as shown in Figure 6, the frequency of the AC power source is increased to 1.
00Hzl￥! If set to trace, nematic
The cholesteric liquid crystal 76 is irregularly arranged, becomes cloudy, and enters a state in which incident light does not pass through (shutter closed state).

Next, as shown in FIG. 5, a predetermined voltage V is applied to the display element 142, and at the same time, the frequency of the AC power source 80 is changed to 10 KHz.
When the liquid crystals are switched to a certain degree, the nemonedic cholesteric liquid crystals 76 are arranged in a regular manner, and the incident light is transmitted (
The shirt is in an open state). Therefore, by switching the frequency of the AC power supply 80, the opening and closing of the liquid crystal shutter 70 can be easily controlled.

Further, as shown in FIG. 7, when the power switch 82 is turned off, the nematic/]cholesteric liquid crystal 6 is maintained in the state shown in FIG. The state is such that no light passes through it (the shirt is closed). In other words, there is no risk of fire or the like even if the vehicle is left unattended for a long period of time.

As explained above, according to the embodiment of the present invention, by combining the functions of a half mirror for detecting the incidence of external light such as sunlight and an optical shutter, it is possible to reduce the weight and stress of the HLJ D unit. be able to. In addition, the LCD screen I7
Maintenance of the ivy becomes easier, and the number of man-hours required for installation is greatly reduced.

[Efficacy of the Invention rA1 As explained above, the present invention is used as a control means for controlling the amount of external light incident on the HUD unit when the external light incident Q=J fl is equal to or higher than a predetermined value. By including a half mirror, an optical shutter, or a liquid crystal shutter, it is possible to effectively prevent burnout and deterioration of the display element due to the incidence of external light.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of the vehicle bed-up display device according to the present invention, Fig. 2 is a control block diagram of the seat opening/closing control circuit, and Fig. 3 is a dimensional diagram showing the relationship between sunlight illuminance and comparator horn voltage. , Fig. 4 is an explanatory diagram of the configuration of a head-up display device for a vehicle according to the present invention, Figs. FIG. 10 is a diagram illustrating a schematic configuration of the device. FIG. 10 is a specific diagram illustrating problems caused by a conventional head-up display device. 36... Instrument panel 38, 13
8-1-I U r) E chive h/1.0.140
... Illumination lamp 42.142 ... Display element 44 ... Windshield 46.146 ... Optical lens 48.148 ... Detection sensor 50 ... Half mirror 51 ... Optical shutter 58 ... ... Control unit 70 ... Liquid crystal V ivy 70.7/l ... Glass 76 ... Nemane) Ic cholesteric liquid crystal.

Claims (2)

[Claims] (1) A display means for displaying various driving conditions of the vehicle by light irradiation from the light projecting means, an optical lens for forming an image displayed by the display means on the vehicle windshield, and a display means for controlling external light incident on the display means. In a head-up display device for a vehicle, the vehicle head-up display device includes a detection means for detecting a signal, and a control means for controlling the amount of incident external light when the amount of incident external light is equal to or higher than a predetermined value. It includes a half mirror and an optical shutter provided between the half mirrors, and detects a part of the external light reflected by the half mirror with an external light detection sensor, and controls the opening and closing of the optical shutter according to the detected value. A vehicle head-up display device characterized by: (2) A display means for displaying various driving conditions of the vehicle by light irradiation from the light projecting means, an optical lens for forming an image displayed by the display means on the vehicle windshield, and a display means for controlling external light incident on the display means. In a head-up display device for a vehicle, comprising a detection means for detecting, and a control means for controlling the amount of incident external light when the amount of incident external light is equal to or higher than a predetermined value,
The control means includes a liquid crystal shutter provided between the display means and the optical lens, and detects a part of the external light reflected by the liquid crystal shutter using an external light detection sensor, and detects a portion of the external light reflected by the liquid crystal shutter according to the detected value. A head-up display device for a vehicle, characterized in that the transmittance of a liquid crystal shutter is controlled by