JP2004314860A - Indicating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indicating device enabling a car driver to obtain images with an optimum brightness irrespective of daytime or nighttime. <P>SOLUTION: This invention concerns an indicating device by which a windshield 2 is irradiated with indication light L emitted from indicting means 23, and by which an indication image 4, obtained as a result of this irradiation, is arranged to be visually recognized by overlapping it with the background. This indicating device is equipped with the 1st light sensor (1st external light detection means) 17a, designed to detect the brightness of the afore-mentioned background; the 2nd light sensor (2nd external light detection means) 17b, designed to detect the brightness of surroundings other than the background; and control means, having the 1st light dimming function to dim indication light L from indicating means 23, based on detection signals from the 2nd light sensor 17b, and thereby adjust the brightness of the indication image 4, and the 2nd light dimming function to dim the indication light L from indication means 23, based on detection signals from the 1st light sensor 17a, and thereby adjust the brightness of indication image 4 against the background. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention includes external light detection means for detecting ambient brightness, dims display light from a display means based on a detection signal from the external light detection means, and displays a display image (display luminance). The present invention relates to a display device that adjusts the distance.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a display device that automatically adjusts the brightness of display light emitted from a light emitting display (display means) such as a fluorescent display tube according to the surrounding brightness. For example, a display device including a head-up display detects the brightness (illuminance) in front of the vehicle as a background of a display image obtained by irradiating the display light on a windshield of the vehicle with an external light such as a phototransistor. Means, and controls the display brightness of the display image based on the detection result.When the surroundings are bright, the display brightness is increased, and when the surroundings are dark, the display brightness is reduced, and This is intended to make it easier for the driver of the vehicle to see the display image (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Utility Model Application Laid-open No. Sho 61-42333
[Problems to be solved by the invention]
However, the automatic dimming control of such a display device involves detecting the brightness in front of the vehicle, which is the background of the display image, by the external light detecting means, and adjusting the brightness of the display light from the display. For example, even if it is daytime, the shade is detected and the display light is darkened.Also, even if it is nighttime, the brake light and tail lamp light of the preceding vehicle are detected and the display light is brightened. Adjustment may be performed, and there is a problem that the automatically adjusted display image visually recognized by the driver of the vehicle does not always have the optimum display luminance of the driver.
[0005]
Therefore, the present invention has been made in view of the above-described problem, and has as its object to provide a display device capable of obtaining a display image with an optimum light emission luminance for a driver regardless of day or night. .
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a display device of the present invention irradiates display light emitted from a display means to a windshield or a reflecting member of a vehicle, and a display image obtained by the irradiation. Is a display device that visually recognizes the background by superimposing the background on the background, comprising at least two external light detecting means for detecting ambient brightness, detecting the brightness of the background by one external light detecting means, The brightness of the surroundings other than the background is detected by the light detecting means.
[0007]
A display device according to a second aspect is a display device that irradiates display light emitted from a display unit onto a windshield or a reflecting member of a vehicle and visually recognizes a display image obtained by the irradiation by superimposing the display image on a background. A first external light detecting means for detecting the brightness of the background, a second external light detecting means for detecting a surrounding brightness other than the background, and a second external light detecting means. A first dimming control function for dimming display light emitted from the display unit based on the detection signal and adjusting the brightness of the display image; and a detection signal from the first external light detection unit. Control means for dimming display light emitted from the display means and adjusting the brightness of the display image with respect to the background.
[0008]
According to a third aspect of the present invention, in the display device according to the first or second aspect, each of the external light detecting means has a different directional characteristic.
[0009]
According to a fourth aspect of the present invention, in the display device according to the second or third aspect, the first external light detecting means detects the brightness in front of the vehicle as the background, and The first and second external light detecting means are provided on the case body of the display means so that the second external light detecting means detects the ambient brightness other than that detected by the first external light detecting means. It is provided for.
[0010]
According to a fifth aspect of the present invention, in the display device according to any one of the second to fourth aspects, the directional characteristic of the first external light detecting means is the second external light detecting means. The directional characteristics are set narrower than the directivity characteristics of the means.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0012]
As shown in FIG. 1, A is a display unit (display device) as a head-up display device. This display unit A is disposed in the dashboard 1 of the vehicle, and the display unit A displays The light L is reflected by the windshield 2 in the direction of the driver 3 who is the observer, and the driver 3 can observe the display image 4 by superimposing it on the scenery.
[0013]
FIG. 2 is a sectional view of the display unit A. Reference numeral 5 denotes a light-emitting element group including a plurality of light-emitting diodes. The light-emitting element group 5 has a liquid crystal display element 6 on the illumination direction side and emits display light L. Reference numeral 7 denotes a circuit board, and the circuit board 7 is connected to the light emitting element 5 group and the liquid crystal display element 6. Reference numeral 8 denotes a heat radiating member, and the heat radiating member 8 has a large number of heat radiating fins 9. The heat dissipating member 8 is provided on the back surface side of the light emitting element 5 via the circuit board 7 and the silicone-based heat transfer member 10.
[0014]
Reference numeral 11 denotes a housing (case body), in which the light emitting element 5 group, the circuit board 7 and the like are accommodated. An opening 12 from which the display light L is emitted is provided in the housing 11, and a light-transmitting cover 13 made of a light-transmitting resin (eg, acrylic) is provided in the opening 12. A reflecting mirror 14 reflects the display light L in the direction of the opening 12. Reference numeral 15 denotes a light-shielding wall. The light-shielding wall 15 is formed integrally with the housing 11 to prevent external light such as sunlight from entering the liquid crystal display element 6 and making the display image 4 difficult to see (washout). are doing. The light shielding wall 15 is provided with a through hole 16 formed at a position facing an optical sensor described later.
[0015]
Reference numeral 17 denotes an external light detecting means including a phototransistor and the like, and has first and second optical sensors 17a and 17b. The first optical sensor 17a has a narrow directional characteristic (detection range) of, for example, ± 6 °, and detects the brightness in front of the vehicle, which is the background of the display image 4 shown in FIG. Light transmitted through the translucent cover 13 and passed through a through hole 16 provided in the light shielding wall 15 is detected. The second optical sensor 17b has a wide directional characteristic of, for example, ± 55 °, and detects the brightness on the dashboard 1 (the windshield 2), that is, the surrounding brightness other than the background. The light transmitted through the glass 2 and the translucent cover 13 is detected. (See FIG. 1). The first and second optical sensors 17a and 17b are electrically connected to the circuit board 7 provided behind the light shielding wall 15.
[0016]
Next, the electrical configuration of the display unit A will be described with reference to FIG. Reference numeral 17 denotes external light detecting means, which includes first and second optical sensors 17a and 17b, and is disposed in the display unit A as described above. The first and second optical sensors 17a and 17b detect the surrounding brightness within a detection range set based on each directional characteristic, and generate a detection signal which is an analog signal corresponding to the surrounding brightness, as described later. Output to the control means.
[0017]
Reference numeral 20 denotes control means mainly constituted by a microcomputer. The control means 20 performs arithmetic processing based on each detection signal from the external light detection means 17, and also temporarily stores a CPU (central processing unit) 20 a as means for executing processing to be described later, and a calculation processing result in the CPU 20 a. RAM (storage unit) 20b serving as a read / write rewritable working memory, ROM 20c serving as a read-only program memory storing a control program, and reference values and set values used when performing a determination process of a process described later. And a storage unit 20d composed of an EEPROM, a backup RAM, or the like in which is stored. The respective units are connected by a bus. The control means 20 includes an input interface (not shown) provided with an A / D converter for converting a detection signal output from the external light detection means 17 into a digital signal, a light emitting element group 5 and a liquid crystal display. An output interface (not shown) for driving the element 6 is provided. Further, the control means 20 executes a process of inputting vehicle information from an ECU or various sensors mounted on the vehicle and causing the liquid crystal display element 6 to display a predetermined display mode.
[0018]
Reference numerals 21 and 22 denote driving circuits for driving the light emitting element 5 and the liquid crystal display element 6, respectively. The light emission luminance of the light emitting element 5 is changed by each control signal from the control means 20, and a predetermined value is determined by the liquid crystal display element 6. Is displayed.
[0019]
The group of light emitting elements 5 is in a state where each of the light emitting diodes can be adjusted in brightness by the PWM control by the control means 20 and a state in which a predetermined number of light emitting diodes can be adjusted in brightness by the PWM control by the control means 20 in groups. Mounted on the circuit board 7. The light-emitting elements 5 are adjusted in light-emitting luminance by inputting a control signal from the control means 5 through the drive circuit 21.
[0020]
The liquid crystal display element 6 displays predetermined vehicle information such as a vehicle speed, an engine speed, a turn signal, and vehicle guidance information by inputting a control signal from the control means 20 via a drive circuit 22. The drive circuit 22 receives a control signal from the control unit 20 and converts it into a drive signal for obtaining a predetermined display mode. The display means 23 is configured by the above-described light emitting element group 5 and the liquid crystal display element 6.
[0021]
Next, a method of adjusting the luminance of the display unit A will be described with reference to FIG.
[0022]
The control means 20 inputs a detection signal according to the surrounding brightness from the second optical sensor 17b having a wide directivity characteristic (step S1), and obtains brightness data according to the surrounding brightness by a predetermined arithmetic processing. At the same time, day / night determination is performed based on predetermined brightness information such as the size of the brightness data and the duration of the brightness data (step S2). When the brightness data is larger than a predetermined reference value and the brightness data larger than the reference value is continuously obtained for a predetermined time or more (duration), the control unit 20 sets the brightness adjustment level to a brighter surrounding. When the daytime (daytime) adjustment mode is set (step S3), and the brightness data is equal to or less than the reference value and the brightness data equal to or less than the reference value is continuously obtained for a predetermined time or more, the surrounding area is set. Is set to the night adjustment mode when the brightness of the image is dark (step S4: first dimming control function). The day / night determination is also performed when the vehicle enters the tunnel.
[0023]
That is, in the daytime adjustment mode, the control means 20 performs display so as to obtain a good contrast between the background when the surroundings are bright and the display image 4 (the emission luminance of the display light L from the liquid crystal display element 6). The emission brightness of the light L is set to be higher than that in the night adjustment mode, and in the night adjustment mode, the display light is adjusted so that the contrast between the background when the surroundings are dark and the display image 4 is excellent. The light emission luminance of L is set (dimming setting) so as to be lower than that in the daytime adjustment mode.
[0024]
Next, after setting the daytime adjustment mode and the nighttime adjustment mode, the control means 20 reduces the brightness in front of the vehicle (the brightness of the background of the display image 4) from the first optical sensor 17a having a narrow directional characteristic. A corresponding detection signal is inputted (step S5), luminance data is obtained by a predetermined arithmetic processing in accordance with the detection signal, and the brightness of the display image 4 with respect to the background is set to a predetermined appropriate brightness (background and display). The dimming control of the group of light emitting elements 5 is performed so that the contrast with the image 4 becomes optimum (step S6: second dimming control function).
[0025]
In step S6, for example, dimming control that optimizes the contrast between the background and the display image is obtained by the display device proposed by the present application in Japanese Patent Application Nos. 2003-94021 and 2003-94022. be able to.
[0026]
By repeating the processing from step S1 to step S6, the dimming control in each adjustment mode can be performed while switching between the daytime adjustment mode and the nighttime adjustment mode.
[0027]
The display unit A irradiates the windshield 2 of the vehicle with the display light L emitted from the display means 23 composed of the liquid crystal display element 6 and the light emitting element 5 group, and displays the display image 4 obtained by this irradiation in the background. A first light that detects at least two light sensors 17a and 17b that detect ambient brightness and that is related to a display device that is superimposed and visually recognized, and that detects the brightness of the background of the display image 4. Dimming the display light L emitted from the display means 23 based on a sensor 17a, a second optical sensor 17b for detecting ambient brightness other than the background, and a detection signal from the second optical sensor 17b; The mode is switched to the daytime / nighttime adjustment mode in which the brightness of the display image 4 is largely changed, and the detection from the first optical sensor 17b is performed in the dimming control for fine adjustment after the daytime / nighttime adjustment mode. Control means 20 for adjusting the brightness of the display image 4 by a dimming control mode for adjusting the brightness of the display image 4 with respect to the background by adjusting the display light L emitted from the display means 23 based on the signal. , Is provided. The first and second optical sensors 17a and 17b have different directional characteristics, respectively, and the first optical sensor 17a detects the brightness in front of the vehicle serving as the background. The first and second optical sensors 17a and 17b are provided in the housing 11 of the display unit A so that the ambient light other than that detected by the first optical sensor 17a is detected by the second optical sensor 17b. is there. Therefore, the brightness of the front of the vehicle, which is the background of the display image, is detected by a single optical sensor, and the external brightness of the shade, the front vehicle, and the like is compared with the conventional display device in which the display brightness of the display image is adjusted. Since the influence is hardly affected, the dimming control in the day and night can be accurately performed.
[0028]
Further, the directional characteristics of the first and second optical sensors 17a and 17b are different from each other, and the directional characteristics of the first optical sensor 17a are set narrower than the directional characteristics of the second optical sensor 17b. In the dimming control, which is a fine adjustment after the daytime and nighttime adjustment modes, the brightness of the surroundings other than the brightness of the background of the display image 4 is not detected, so that the brightness of the display image 4 with respect to the background is accurately adjusted. Light control becomes possible.
[0029]
In the embodiment of the present invention, the display unit A for projecting the display light L on the windshield 2 has been described as an example. However, in the present invention, the display light L can be favorably operated on the windshield 2. The display device may be provided with a combiner film that reflects light in the direction of the user 3 or may project the display light L on a dedicated reflection member different from the windshield 2.
[0030]
【The invention's effect】
The present invention relates to a display device that irradiates display light emitted from a display unit onto a windshield or a reflecting member of a vehicle and superimposes a display image obtained by this irradiation on a background to be visually recognized by a driver regardless of day or night. It is possible to obtain a display image having an optimum light emission luminance.
[Brief description of the drawings]
FIG. 1 is a diagram showing a display unit mounted on a vehicle according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the display unit according to the embodiment;
FIG. 3 is a block diagram showing the embodiment.
FIG. 4 is a flowchart showing a processing procedure of a microcomputer in the embodiment.
[Explanation of symbols]
2 Windshield 3 Driver 4 Display image 5 Light emitting element 6 Liquid crystal display element 11 Housing (case)
17 external light detecting means 17a first optical sensor 17b second optical sensor 20 control means 23 display means A display unit L display light

Claims (5)

A display device that irradiates display light emitted from a display unit onto a windshield or a reflecting member of a vehicle, and visually recognizes a display image obtained by the irradiation by superimposing the display image on a background,
At least two external light detecting means for detecting ambient brightness, one external light detecting means detecting the brightness of the background, and the other external light detecting means detecting ambient brightness other than the background. A display device, comprising: A display device that irradiates display light emitted from a display unit onto a windshield or a reflecting member of a vehicle, and visually recognizes a display image obtained by the irradiation by superimposing the display image on a background,
First external light detection means for detecting the brightness of the background,
Second external light detection means for detecting the surrounding brightness other than the background,
A first dimming control function for dimming display light emitted from the display unit based on a detection signal from the second external light detection unit and adjusting brightness of the display image; Control means having a second dimming control function for dimming display light emitted from the display means based on a detection signal from the external light detection means and adjusting the brightness of the display image with respect to a background;
A display device comprising: The display device according to claim 1, wherein each of the external light detection units has a different directional characteristic. The first external light detecting means detects the brightness in front of the vehicle as the background, and the second external light detecting means detects the ambient brightness other than that detected by the first external light detecting means. 4. The display device according to claim 2, wherein the first and second external light detection units are provided on a case body of the display unit so as to detect the external light. 5. 5. The directional characteristic of the first external light detecting means is set to be narrower than the directional characteristic of the second external light detecting means. Display device.

Images