JPH02117413A - Liquid crystal sun visor for vehicle - Google Patents

Abstract

PURPOSE:To securely shield sunlight while sufficiently maintaining a front field of view by a method wherein a liquid crystal apparatus is mounted on an approximately entire surface of at least right, left and upper sections of a front glass and variably controlled according to output of an optical sensor, a speed sensor and a wheel angle detecting means. CONSTITUTION:A liquid crystal portion 5 of a liquid crystal apparatus 4 is mounted between two pieces of toughened glass 2, 3 of a front glass 1, said liquid crystal portion 5 comprising a plurality of transparent X and Y electrodes 12, 13 provided inside a pair of bases 9 made of transparent plastic or the like, a pair of deflecting boards 10, 11 being high polymer transparent thin films provided inside both electrodes 12, 13, a liquid crystal 14 sealed between both deflecting boards 14, 15, etc. The respective electrodes 12, 13 are connected to input ports X1 to Xn and Y1 to Ym of driving circuits 15, 16 respectively, and by controlling power supply to each port via a controller according to output of an optical sensor, a wheel angle sensor and a speed sensor, light shielding status corresponding to driving state can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal sun visor for an automobile, and more particularly to one in which the light-shielding portion of a liquid crystal device mounted on a windshield is controlled according to the driving state of the automobile.

[Prior art]

Generally, when driving a car on a sunny day, sunlight that enters the driver's eyes through the windshield is blocked by a sun visor mounted above the driver's seat in an adjustable position. However, as the direction of incidence of sunlight changes vertically and horizontally due to steering while driving,
This sun visor was unable to sufficiently block sunlight.

Recently, liquid crystal sun visors and liquid crystal spot visors for automobiles have been proposed in which a liquid crystal device is incorporated into the windshield and the liquid crystal device blocks sunlight.

For example, in Japanese Utility Model Application Publication No. 60-52116, a liquid crystal device is attached to the windshield, the direction of the light source (sun) and the seat position are detected by sensors, and the liquid crystal display is displayed according to the direction of the light source and the seat position. A liquid crystal type spot heightizer is described that prevents sunlight from entering the driver's eyes by variably controlling the position of a small rectangular light shielding part in the device.

[Problem to be solved by the invention]

In the liquid crystal spot visor described in the above-mentioned Japanese Utility Model Publication No. 60-52116, the position of the light shielding part of the liquid crystal device is controlled based on the direction of the light source and the seat position. However, the position of the driver's eyes differs slightly depending on various conditions such as the driver's height and seat position, so a small rectangular light shield cannot reliably block sunlight from entering the driver's eyes. There's a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal sun visor for an automobile that can reliably block sunlight while ensuring sufficient forward visibility.

[Means to solve the problem]

A liquid crystal sun visor for an automobile according to the present invention includes a liquid crystal device attached to at least the entire left, right, and upper portions of a windshield, an optical sensor that detects sunlight, a vehicle speed sensor that detects vehicle speed, and a steering wheel. The device includes a steering angle direction detection means for detecting a direction, and a control means for variably controlling a light-blocking portion of the liquid crystal device in response to detection signals from an optical sensor, a vehicle speed sensor, and a steering angle direction detection means. .

[Effect]

In the automotive liquid crystal sun visor according to the present invention, the control means is based on the light amount signal from the optical sensor, the vehicle speed signal from the vehicle speed sensor, and the steering angle direction signal from the steering angle direction detection means, and by a combination of these signals. , variably controls the light-shielding portion of a liquid crystal device mounted on substantially the entire surface of at least the left, right, and upper portions of the windshield.

〔Effect of the invention〕

According to the liquid crystal sun visor for an automobile according to the present invention, as explained above, the liquid crystal device is mounted on substantially the entire surface of at least the left, right and upper portions of the windshield that do not obstruct the view for checking the front, The light-shielding part of the liquid crystal device is variably controlled depending on whether the vehicle is running at low speed, high-speed, or the direction of steering, so the light-shielding part can be changed depending on the driving condition, ensuring sufficient visibility in the direction of travel and keeping the driver's eyes clear. It can reliably block sunlight from entering.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First, the structure of the windshield 1 will be explained based on FIG. 1.

This windshield 1 is a light control glass equipped with a liquid crystal part 5, and includes two pieces of tempered glass 2 and 3;
3 and the liquid crystal section 5 of the liquid crystal device 4 mounted between the
and the tempered glass 2, and an antenna wire 8 wired between the liquid crystal part 5 and the tempered glass 3.

Next, regarding the liquid crystal section 5 of the liquid crystal device 4, FIGS.
This will be explained based on the diagram.

The liquid crystal section 5 includes a pair of substrates 9 made of transparent plastic or the like, transparent X electrodes 12 and 13 provided immediately inside each of the pair of substrates 9, and a picture electrode 1.
A pair of polarizing plates 10 and 11, each of which is a transparent thin film made of a polymer, is provided inside each of the polarizing plates 10 and 13.
It consists of a liquid crystal 14 sealed between 11 and 11. still,
The polarizing plate lO and the polarizing plate 11 have polarization directions of 9
They differ by 0°.

As shown in FIG. 2, this X electrode 12 is a horizontally long strip-shaped electrode having a predetermined width extending from the left end to the right end of the windshield 1. (n rows).

Further, the X electrode 13 is a longitudinally long strip-shaped electrode having a predetermined width from the upper end to the lower end of the windshield 1,
m pieces (m rows) of these X electrodes 13 are provided at small intervals in the left-right direction. As shown in FIG. 2, the rectangular intersections of each X electrode 12 and each Y electrode 13 are arranged in a matrix of n rows and m columns.

The liquid crystal 14 has, for example, a twisted nematic (TN) mode, and the twisted nematic liquid crystal at the intersection of the X electrode 12 and the X electrode 13 has a voltage applied to its picture electrodes 12 and 13. When it is not present, it transmits light due to its optical rotation, but when a voltage is applied to the picture electrodes 12 and 13, it loses most of its optical rotation and thus blocks the transmission of light.

Next, a control system for controlling the liquid crystal section 5 will be explained based on the second block diagram.

Each of the n X electrodes 12 is connected to each input port X1, X2, X3...Xn of the drive circuit 15, and each of the m Y electrodes 13 is connected to each input port Yl, Xn of the drive circuit 16.
Y2, Y3... are connected to Ym. Here, the drive circuit 15 and the drive circuit 16 constitute a drive section 6, and the liquid crystal device 4 includes a liquid crystal section 5 and a drive section 6. The drive circuit 15 supplies a drive pulse to a specific X electrode 12 according to an input drive signal while scanning the group of X electrodes 12 line-sequentially at a frame period of about 20 m5 or less.

In addition, the drive circuit 16 synchronizes with the drive circuit 15 and supplies a drive pulse to a specific Y electrode 13 according to the input drive signal while sequentially scanning the group of X electrodes 13 at a frame period of approximately 20 m5 or less. It is something.

The CPU (central processing unit) 18 of the control device 17 includes both drive circuits 15 and 16 and an optical sensor 1 that detects the amount of sunlight.
9 is connected to a steering angle sensor 20 that detects the steering direction and angle of the steering wheel, and a vehicle speed sensor 21 that detects the running speed of the vehicle, and is also connected to a battery 23 via a start switch 22. In addition, codes 19a, 20a, 2
1a is an A/D converter, respectively.

The control bag W17 includes a CPU 18 and a ROM (read-only) connected to the CPU 18 via a data bus or the like.
It consists of a memory (memory) 24 and a RAM (random access memory) 25.

The ROM 24 stores the windshield 1 as shown in FIG.
Stop pattern data consisting of a plurality of coordinate data corresponding to each intersection of the matrix is provided such that a light shielding part 26 is provided at the upper part of the matrix, and as shown in FIG. The right turning pattern L1 is made up of a plurality of coordinate data corresponding to each intersection point of the matrix so that the light-shielding portion is provided outside the left and right dashed lines, and the left and right two-way pattern L1 similarly includes the upper light-shielding portion 26. A right-turning pattern L2 in which a light-shielding portion is provided outside the dashed dot line, and a right-turning pattern L3 in which a light-shielding portion is provided outside the left and right three-dot chain lines, including the upper light-shielding portion 26.
, as shown by diagonal lines in FIG. 4, a straight low-speed running pattern L4 that includes the upper light shielding portion 26 and has the light shielding portion outside the left and right solid lines; A left-turning pattern L5 in which a light-shielding portion is provided in a portion, a left-turning pattern L6 in which a light-shielding portion is provided in a portion including the upper light-shielding portion 26 and outside the left and right six-dot chain lines, and a left-hand turning pattern L6 including the upper light-shielding portion 26 and outside the left and right seven-dot chain lines. A left turning pattern L7 in which a light-shielding portion is provided in a portion, and furthermore, as shown in FIG. A right turning pattern H consisting of a plurality of coordinate data corresponding to each intersection point of the matrix
1. Similarly, a right-turning pattern H2 that includes an upper light-shielding portion 26 and a lower light-shielding portion 27 and has a light-shielding portion outside the left and right dashed double-dot lines; A right-turning pattern H3 in which a light-shielding portion is provided outside the left and right three-dot chain lines, an upper light-shielding portion 26 and a lower light-shielding portion 27 as shown by diagonal lines in FIG.
Straight high-speed driving pattern data H4 in which a light-shielding portion is provided outside the left and right solid lines, and a left-turning pattern that includes an upper light-shielding portion 26 and a lower light-shielding portion 27 and has a light-shielding portion outside the left and right five-dot chain lines. H5, a left-turning pattern H6, which includes an upper light-shielding portion 26 and a lower light-shielding portion 27, and has a light-shielding portion outside the left and right six-dot chain lines;
Left turning pattern H7 including the upper light shielding part 26 and the lower light shielding part 27 and providing the light shielding part outside the left and right 7-dot chain lines, the signal value from the optical sensor 19 when sun visor control is required (set value) , a control program for sun visor control, etc. are stored in advance.

The RAM 25 is provided with various memories, flags, etc. that temporarily store results calculated by the CPU 18.

Next, the sun visor control routine executed by the control device 17 will be explained based on the flowchart of FIG.

This control is started by operating the start switch 22, and initial setting is executed (Sl).

Then, the light amount signal from the optical sensor 19 is read (S2
), it is determined based on the light amount signal whether the light amount is greater than or equal to a set value that requires sun visor control (S3), and if it is greater than or equal to the set value, the vehicle speed signal from the vehicle speed sensor 21 is read (
S4). Based on this vehicle speed signal, it is determined whether or not the vehicle is currently stopped (S5). When the vehicle is stopped, stop pattern data is selected and read from the ROM 24, and a drive signal based on the stop pattern data is sent to the re-drive circuit 15. 16 (S6), and returns to S2. As a result, drive device 1
5 supplies drive pulses to a plurality of specific X electrodes 12 based on the drive signal while scanning the 12 groups of X electrodes line-sequentially, and a drive device 16 supplies drive pulses to a specific plurality of X electrodes 12 based on the drive signal while scanning the 13 groups of Y electrodes line-sequentially. Since the driving pulse is supplied to a plurality of specific Y electrodes 13, the liquid crystal 14 at the intersection of the specific X electrode 12 and the specific Y electrode 13 loses its optical rotation ability and blocks the transmission of light. As shown in Figure (a), a light shielding portion 26 is provided at the top of the windshield.

Then, when the car starts driving, NO is selected in S5.
Based on the vehicle speed signal, it was determined that the speed was approximately 50 Km/
When the vehicle is traveling at a low speed slower than H, the determination in S7 is Yes, and the vehicle speed flag FL is reset (S8). next,
The steering direction signal and the steering angle signal from the steering angle sensor 20 are read (S9), it is determined whether or not the vehicle is traveling straight (SIO), and if the vehicle is traveling straight and at low speed (511), a low speed travel pattern L4 for straight travel is selected. data is selected and read out,
Drive signals based on the data of pattern L4 are output to the re-drive circuits 15 and 16 (512), and the process returns to S2.

As a result, as shown in FIG. 7(b), the windshield l
A light-shielding portion corresponding to the low-speed traveling pattern L4 is provided.

Here, when the steering wheel is operated to turn left while driving at low speed, it is determined as No at 510, Yes is determined at S13, and Yes is determined at 514 based on the steering direction signal, and the left turning patterns L5 to L7 are determined. Left turning patterns L5 to L7 based on the steering angle are selected from among them, and drive signals based on the selected left turning patterns L5 to L7 are output to redrive circuits 15 and 16, respectively (S15), and then to S2. return. As a result, as shown in FIG. 7(C), the windshield l is provided with a light shielding portion corresponding to any of the selected left turning patterns L5 to L7.

Further, when the vehicle turns to the right by operating the steering wheel while driving at low speed, it is determined Yes in S13 and NO in S14 based on the steering direction signal, and the right turning pattern Ll-L3
A right turning pattern Ll-L3 based on the steering angle is selected from among them, and drive signals based on the selected right turning pattern Ll-L3 are output to the re-drive circuits 15 and 16, respectively (S16), Return to S2. As a result, the windshield 1 is provided with a light-shielding portion corresponding to any one of the selected right-turning patterns L1 to L3.

Next, when driving straight ahead at a high speed of about 50 Km/H or more, the determination is NO in S7, the vehicle speed flag FL is set (S17), and after going through S9 to SIO, it is determined No in Sll, and the straight high speed traveling pattern is determined. H4 is selected and read out, and drive signals based on the data of pattern H4 are output to the re-drive circuits 15 and 16, respectively (31B), and the process returns to S2. As a result, as shown in FIG. 7(d), a light-shielding portion corresponding to the high-speed travel pattern H4 is provided on the windshield l.

Here, when driving at high speed and turning left by operating the steering wheel, it is determined No in SIO and S13, and Yes is determined in S19 based on the steering direction signal, and based on the left turn pattern H5 to H7, the steering angle is The left turning patterns H5 to H7 are selected, and drive signals based on the selected left turning patterns H5 to H7 are sent to the re-drive circuits 15 and 16.
(S20), and the process returns to S2. As a result, as shown in FIG. 7(e), the windshield l is provided with a light shielding portion corresponding to any of the selected left turning patterns H5 to H7. Also, when driving at high speed and turning to the right by operating the steering wheel, S19 is activated based on the steering direction signal.
o, the right turning patterns H1 to H3 based on the steering angle are selected from the right turning patterns H1 to H3, and the drive signal based on the selected right turning patterns H1 to H3 is image driven. Output to circuits 15 and 16 respectively (S21)
, return to S2. As a result, the windshield 1 is provided with a light-shielding portion corresponding to any one of the selected right-turning patterns H1 to H3.

As explained above, based on the light amount signal from the optical sensor 19, the steering direction signal and steering angle signal from the steering angle sensor 20, and the vehicle speed signal from the vehicle speed sensor 21, the light-shielding portion of the windshield l is adjusted when driving at low speed. The light transmitting area is made relatively wide so that the driver can see what's ahead, and when driving at high speeds, when visibility may be somewhat narrow, the light blocking area is controlled to be large. When changing, the light shielding part is controlled so that the transparent part is moved in the turning direction to expand the visibility in the turning direction.
The windshield 1 is provided with a light-shielding portion that changes depending on the driving condition, and it is possible to secure sufficient visibility in the direction of travel and reliably block sunlight from entering the driver's eyes.

Note that the liquid crystal section 5 may be attached to the upper, left, and right parts of the windshield 1 that are minimum necessary for blocking sunlight.

The ROM 24 is configured to store a straight-ahead low-speed travel pattern L4 and a high-speed travel pattern H4, and to shift between the low-speed travel pattern L4 and the high-speed travel pattern H4 according to the steering angle signal and steering direction signal from the steering angle sensor 20. The direction and shift amount may be calculated and controlled.

Incidentally, the windshield 1 may be a windshield IA configured as follows. That is, as shown in FIG. 8, the heating wires 7 are arranged in the left-right direction at predetermined intervals, and the antennas are arranged horizontally at predetermined intervals. Ill? ! 8 are arranged in the vertical direction at predetermined intervals, the X electrode 12 is arranged between each heating wire 7 with a slight gap between the heating wire 7 and the The polarizing plates 10 and 11 may be disposed with a gap, and the liquid crystal 14 may be sealed between the polarizing plates 10 and 11.

In place of the steering angle sensor 20 in the embodiment described above, a steering direction detection sensor consisting of a proximity switch for detecting the steering direction from the steering system, for example, is provided, and when driving, for example, three types of light shielding patterns L2 are provided based on the detection signal.
, L4, L6, or the light shielding patterns H2, H4, H6.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; Fig. 1 is a vertical cross-sectional side view of the windshield, Fig. 2 is a block diagram of the control system for sun visor control, and Part 3 is an explanatory diagram explaining the light-shielding part when the vehicle is stopped. , Figure 4 is an explanatory diagram explaining the light shielding part when steering left and right when driving at low speed, Figure 5 is a diagram equivalent to Figure 4 when steering left and right when driving at high speed, and Figure 6 is an illustration of the sun visor control routine. Schematic flowchart, Figures 7(a) to (e)
8 is an explanatory diagram illustrating a light shielding portion controlled by a sun visor, and FIG. 8 is a diagram corresponding to FIG. 1 of a windshield according to a modified example. 1.IA...windshield, 4..liquid crystal device, 5.
・Liquid crystal section, 6..Drive section, 12..X electrode, 13
・・Y electrode, 14・・Liquid crystal, 17・・Control device,
18...CPU, 19...Light sensor, 20...
Steering angle sensor, 21...Vehicle speed sensor, 24...
ROM, 25...RAM.

Claims (1)

[Claims] (1) A liquid crystal device attached to at least the entire left, right, and upper portions of the windshield, an optical sensor that detects sunlight, a vehicle speed sensor that detects vehicle speed, and a steering angle direction that detects the steering direction. A liquid crystal sun visor for an automobile, comprising: a detection means; and a control means for variably controlling a light shielding portion of the liquid crystal device in response to detection signals from the optical sensor, the vehicle speed sensor, and the steering angle direction detection means. .