JPH02117414A - Liquid crystal spot visor of vehicle - Google Patents

Abstract

PURPOSE:To exactly shield sunlight by a method wherein a liquid crystal apparatus is mounted on a front glass, a direction of sunlight is calculated by detecting directions of sunlight with respect to a vehicle in two planes orthogonal to each other, and a position of a light shielding portion of the liquid crystal apparatus is controlled according to the directions. CONSTITUTION:First and second direction detectors 1, 8 comprise light shielding boards 3, 10 having slits 2, 9 orthogonal to each other, two cylindrical lenses 4, 5; 11, 12, and optical sensors 6, 13 comprising CCD linear image sensors, etc. A liquid crystal portion 19 to be mounted on a front glass comprises a plurality of transparent X and Y electrodes arranged laterally and longitudinally, a pair of polarizing plates provided inside the electrodes, a liquid crystal sealed between the polarizing plates, etc. The X and Y electrodes are connected to respective input ports X1 to Xn and Y1 to Ym of driving circuits 27, 28, and power supply to each port is controlled according to the direction of sunlight calculated from output of the first and second direction detectors 1, 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid crystal spot visor for a vehicle, and in particular to a liquid crystal spot visor for a vehicle that controls the position of a light shielding part of a liquid crystal device attached to a windshield according to the direction of sunlight. related to what was done.

[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. 60-53116, 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 device is displayed according to the direction of the light source and the seat position. A liquid crystal spot visor is described that prevents sunlight from entering the driver's eyes by variably controlling the position of a small rectangular light shielding part.

However, this publication does not sufficiently disclose a technique for detecting the direction of a light source using an optical sensor.

Here, as a technique for detecting the direction of a light source, for example, Japanese Utility Model Application Publication No. 63-21811 discloses a light shielding member having one dot-shaped hole and a large number of photoelectric conversion elements (CCD) arranged in a matrix. A two-dimensional optical sensor is described in which the direction of the light source is detected based on the position (coordinates) of the photoelectric conversion element where the light passing through the hole reaches.

[Problem to be solved by the invention]

In the two-dimensional optical sensor described in the above-mentioned Japanese Utility Model Publication No. 63-21811, a large number of photoelectric conversion elements are provided two-dimensionally, so when trying to detect the incident direction of light over a relatively wide range, the sensor itself There are problems in that the photoelectric conversion element becomes large in size, the control for detecting the direction becomes complicated, and the cost of the photoelectric conversion element becomes extremely high.

An object of the present invention is to detect the direction of sunlight in two orthogonal planes relative to a vehicle using a detector with a simple configuration, to determine the direction of sunlight, and to reliably block sunlight according to the direction of the sunlight. The purpose of the present invention is to provide a liquid crystal spot visor for vehicles.

[Means to solve the problem]

A liquid crystal spot visor for a vehicle according to the present invention includes a liquid crystal device attached to a windshield, a first direction detector and a second direction detector that respectively detect the direction of sunlight relative to the vehicle in two mutually orthogonal planes. a first direction detector and a second direction detector.
The control means receives the detection signal from the direction detector to determine the direction of sunlight relative to the vehicle, and controls the position of the light shielding part of the liquid crystal device according to the direction of the sunlight.

[Effect]

In the liquid crystal spot visor for a vehicle according to the present invention,
The first direction detector and the second direction detector each detect the direction of sunlight relative to the vehicle in two mutually orthogonal planes, and output the detection signals to the control means, respectively. The control means determines the direction of sunlight relative to the vehicle based on these detection signals, and variably controls the position of the light shielding part of the liquid crystal device mounted on the windshield according to the direction of the sunlight.

〔Effect of the invention〕

According to the liquid crystal spot visor for a vehicle according to the present invention, as explained above, the direction of sunlight relative to the vehicle is decomposed into two directional components by the first direction detector and the second direction detector and detected respectively. Therefore, the detector for detecting the direction of light does not need to be enlarged, and the two-directional components of the direction of sunlight can be accurately detected using a detector with a simple configuration. The direction of sunlight is accurately determined from these two-directional components, and the position of the light shielding part of the liquid crystal device is controlled according to the direction of sunlight, and the direction of sunlight relative to the vehicle changes as the vehicle travel direction changes. However, even if the spot visor is used, the light can always be blocked by the light blocking portion, so it can be used as an ideal spot visor.

〔Example〕

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

First, the direction of sunlight relative to the car is divided into two directions: a first direction in the vertical plane, a left-right direction, and a second direction in the horizontal plane.
The first direction detector 1 and the second direction detector 8, which decompose into directional components and detect them respectively, will be explained.

As shown in FIG. 1, the first direction detector l has a slit 2
It consists of a light shielding plate 3 having a light shielding plate 3, two convex cylindrical lenses 4 and 5, a first degree optical sensor 6 consisting of a CCD type linear image sensor having N pixels, and a case 7 that holds these in a predetermined position. .

The light-shielding plate 3, the lens 4, the lens 5, and the first photosensor 6 are arranged parallel to each other in order as shown in the figure, and the lenses 4 and 5 are located approximately three-dimensionally between the light-shielding plate 3 and the first photosensor 6. The first photosensor 6 is provided at approximately the focal point of the lens 4 . Further, the slit 2 is provided in the vertical direction (Y direction in the drawing) center of the light shielding plate 3 and is oriented in the left-right direction (X direction in the drawing), and the first optical sensor 6 is arranged opposite to the center of the slit 2 in the X direction. The pair of cylindrical lenses 4 and 5 are provided with their lens orientations rotated by 90'' relative to each other, and the axial direction of the lens 5 that is closer to the first optical sensor 6 is oriented in the Y direction. It is disposed perpendicular to the optical sensor 6.

As shown in FIG. 2, the second direction detector 8, like the first direction detector 1, consists of a light shielding plate 10 having a slit 9, two cylindrical lenses 11 and 12, and a CCD type linear image sensor. It consists of a second optical sensor 13 and a case 14 that holds them in a predetermined position. That is, in the second direction detector 8, the first direction detector 1 is rotated by 90 degrees with the X direction and a direction orthogonal to the X direction as rotation axes, and the slit 9 is oriented in the X direction. These first direction detector 1 and second direction detector 8 are integrally assembled in the state shown in FIGS. It can be installed while maintaining the posture. However, the first direction detector 1 and the second direction detector 8 are not necessarily integrated and may be attached separately. That is, the surface S including the first optical sensor 6 and perpendicular to the light shielding plate 3
1 and the second optical sensor 13 and perpendicular to the light shielding plate 10
2 are orthogonal to each other.

Next, the operation of detecting the X-direction component of the direction of sunlight with the first direction detector 1 will be explained.

As shown in FIG. 3, a component of the light incident through the slit 2 that is parallel to the surface S1 travels straight through the lens 4, is refracted by the lens 5, and reaches the first photosensor 6. On the other hand, as shown in FIG. 4, the component of the incident light parallel to the surface S1 is refracted by the lens 4, travels straight through the lens 5, and is focused on the first optical sensor 6 located at the focal point of the lens 4. Shine.

In other words, the surface S1 of the light that has passed through the slit 2 and entered the
The component parallel to
Since the light reaches the optical sensor 6, the X-direction component of the direction of the sunlight can be detected based on the position of the pixel where the first optical sensor 6 receives the light.

The function of detecting the X-direction component of the direction of sunlight with the second direction detector 8 is similar to the function of detecting the X-direction component of the direction of sunlight described above. The X-direction component of the direction of sunlight can be detected based on the position.

Next, the structure of the windshield 15 will be explained based on FIG. 5.

This windshield 15 is a light control glass equipped with a liquid crystal, and includes two pieces of tempered glass 16 and 17, and the tempered glass 1.
It consists of a liquid crystal part 19 mounted between 6 and 17, a heating wire 21 and an antenna wire (path shown). The hot wire 21
are arranged in the left-right direction at predetermined intervals on the rear surface of the tempered glass 16, and antenna wires are arranged in the vertical direction at predetermined intervals on the front surface of the tempered glass 17.

Next, the liquid crystal section 19 of the liquid crystal device 18 will be explained based on FIGS. 5 and 6.

The transparent X electrode 22 is a horizontally long strip-shaped electrode having a predetermined width extending from the left end to the right end of the windshield 15.
row) is arranged. The transparent X electrodes 23 are longitudinally long strip-shaped electrodes having a predetermined width and extending from the upper end to the lower end of the windshield 15. columns) are arranged.

The liquid crystal 24 is sealed between a pair of deflection plates 25 and 26. Note that the deflecting plates 25 and 26 differ in their deflection directions by 90 degrees.

As shown in FIG. 6, rectangular intersections between each X electrode 22 and each Y electrode 23 are arranged in a matrix of n rows and m columns. The liquid crystal 24 has, for example, a twisted nematic (TN) mode, and the twisted nematic liquid crystal at the intersection of the X electrode 22 and the X electrode 23 has a voltage applied to its picture electrodes 22 and 23. When not present, light is transmitted due to its optical rotation, but the picture electrode 22
When a voltage is applied to 23, it loses most of its optical rotation power and thus blocks the transmission of light.

Next, a control system for controlling the liquid crystal section 19 will be explained based on the block diagram of FIG. 6.

Each of the n X electrodes 22 is connected to each input port (XI, X2, X3...Xn) of the drive circuit 27, and each of the m X electrodes 23 is connected to each input port Y1 of the drive circuit 28. ,
Y2, Y3... are connected to Yn. Here, the drive section 20 is configured by the drive circuit 27 and the drive circuit 28,
The liquid crystal device 18 includes a liquid crystal section 19 and a driving section 20. The drive circuit 27 supplies drive pulses to a plurality of specific X electrodes 22 according to a drive signal input from the control device 29 while scanning the group of X electrodes 22 line-sequentially at a frame period of about 20 m5 or less. . The drive circuit 28 synchronizes with the drive circuit 27 and scans the group of Y electrodes 23 line-sequentially at a frame period of about 20m5 or less, while scanning one or more specific Y electrodes according to a drive signal manually inputted from the control device 29. It supplies a driving pulse to the electrode 23.

The CPU (one-chip central processing unit with input/output ports) 30 of the control device 29 includes both drive circuits 27 and 28,
The correction key 33 is connected to the detection signal input devices 34 and 35, and the battery 38 is connected via the start switch 37.
is connected. In addition, the symbols 34a and 35a are respectively A/
It is a D converter.

The correction key 33 is connected to the liquid crystal section 19 on the windshield 15.
These keys are provided on the instrument panel and are used to move and correct the position of the light shielding portion 39 (see FIG. 8) formed by the light shielding portion 39 (see FIG. 8) upwardly, downwardly, leftwardly, and rightwardly.

The detection signal input device 34 sequentially supplies the clock signal from the clock pulse generator 36 from the first pixel to the Nth pixel among the N pixels constituting the first photosensor 6 in time series. The charge amount of each pixel from the first pixel to the Nth pixel in time series, that is, the detection signal (detection pulse signal) is input, and the detection pulse signal is sequentially output to the CPU 30 in synchronization with the clock signal. At this time, the pixels that have received sunlight output a detection pulse signal of a high level according to the amount of light received.

The detection signal input device 35 operates in the same manner as the detection signal input device 34, and inputs detection pulse signals from the N pixels constituting the second photosensor 13, and sequentially transmits the detection pulse signals to the CPU 30 in synchronization with the clock signal. Output to.

The control device 29 includes a CPU 30 and a ROM (read only memory) 31 and a RAM (random access memory) 32 connected to the CPU 30 via a data bus or the like.

The ROM 31 includes a first optical sensor 6 and a second optical sensor 13.
A position detection routine that calculates the highest level Y-direction pixel position (address) and X-direction pixel position (address) based on the detection pulse signal input from each pixel of A calculation routine that calculates the direction of sunlight relative to the car based on the direction of sunlight, a calculation routine that calculates the position of the light shielding part 39 based on the direction of sunlight, and a signal from a 3-position selector switch (path shown) provided on the instrument panel. Spot visor control consisting of data for setting the size of the light shielding part 39 to a size selected from three sizes based on the data, a control routine for controlling the light shielding position to control the position of the light shielding part 39, etc. The program is stored in advance.

The RAM 32 is provided with various memories, flags, etc. that temporarily store the results of calculations performed by the CPU 30.

Next, the spot visor control performed by the control device 29 will be explained based on the flowchart of FIG.

This control is started by operating the start switch 37, and initial setting is executed (Sl).

Next, the detection pulse signal from the first photosensor 6 is read (S2), and the address a of the pixel with the highest signal level is determined based on the position detection program (S3). next,
The detection pulse signal from the second optical sensor 13 is read (S
4) The atto zone b of the pixel with the highest signal level is determined based on the position detection program (S5).

Next, the X-direction component of the sunlight direction (angle of inclination within surface S1) is determined based on address a, and the X-direction component of the direction of sunlight (angle of inclination within surface S2) is determined based on address b. angle) is determined, and the actual direction of sunlight relative to the vehicle is determined from these X-direction components and X-direction components by calculation (S6). Next, the position of the light shielding part 39 provided on the windshield 15 is calculated based on the direction of the sunlight (S7), and if there is correction value data stored in the RAM 32, the light shielding part 39 is shielded based on the data. The position of the light shielding part 39 is corrected (S8), and light shielding part control data is created using the corrected light shielding part position data and a signal specifying the size of the light shielding part 39, and a drive signal based on this data is transmitted to both drive circuits 2.
It is output on 7/28 (S9). As a result, the drive circuit 2
7 supplies a drive pulse to a specific plurality of X electrodes 22 based on a drive signal while scanning a group of 22 X electrodes line-sequentially, and a drive circuit 28 supplies a drive pulse to a specific plurality of X electrodes 22 based on a drive signal while scanning a group of 23 Y electrodes line-sequentially. A driving pulse is supplied to one or more specific Y electrodes 23. As a result, the liquid crystal 24 at the intersection of the specific X electrode 22 and the specific Y electrode 23 loses its optical rotation ability and blocks the transmission of light, and as shown by the shaded area in FIG. Accordingly, the windshield 15 is provided with a light blocking portion 39 that blocks sunlight. This light shielding part 3
9, since the direction of sunlight relative to the vehicle changes from time to time in response to changes in the running direction of the vehicle, the position of the light shielding portion 39 is variably controlled from time to time in up, down, left and right directions. In addition, the light shielding part 3
9 is provided with a light shielding part 39a for the driver and a light shielding part 39b for the front passenger seat passenger.

Further, when the correction key 33 is operated, Yes is selected in S10.
s is determined, and correction signals corresponding to the operated up, down, left, and right keys are input (Sll),
The position of the light shielding part 39 is corrected according to the correction signal (S
12), the correction value updated by operating the correction key 33 is RA
The data is stored as new correction value data in a predetermined memory of M32 (S13), and the process returns to S2. Then, the steps from S2 onwards are repeated, and the position of the light shielding part 39 is corrected in S8 based on the updated correction value data.

Here, as a supplementary explanation, the position of the light shielding part 39 is determined based on the direction of sunlight and the position of the passenger's eyes with respect to the windshield, but in S7, a standard value is set as the position of the passenger's eyes. The position of the light shielding part 39 is determined using However, the position of the occupant's eyes is not constant depending on the seat position and the occupant's sitting height.

Therefore, as described above, the passenger operates the correction key 33 to freely correct the position of the light shielding part 39 vertically and horizontally to match the position of his/her eyes. Once the occupant makes an appropriate correction by operating the correction key 33, the light shielding portion 39
Since the position is corrected, light can be reliably blocked.

As explained above, the direction of sunlight relative to the car is decomposed into two directional components within the plane S1 and the plane S2 that are orthogonal to each other by the first first detector 1 and the second direction detector 8, and are detected respectively. Therefore, the direction of sunlight can be accurately detected with a simple configuration without increasing the size of the first optical sensor 6 and the second optical sensor 13.

Moreover, the position of the light shielding part of the liquid crystal device 18 is controlled according to the direction of this sunlight, and the position of the light shielding part 39 is corrected according to the command from the correction key 33, so that an ideal spot can be obtained. Becomes a visor.

It is also possible that an optical sensor is provided separately and the above control is executed when the light amount signal from this optical sensor exceeds a set value and the driver requires a spot visor.

Note that the liquid crystal section 19 may be attached only to the minimum necessary portion of the windshield 15 for blocking light as a spot visor.

In the above embodiment, the first direction detector 1 is attached to the vehicle in such a manner that the surface S1 is vertical and the second direction detector 8 is horizontal, the surface S2 being horizontal. They may be mounted in any desired orientation as long as they are orthogonal.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view of a first direction detector, FIG. 2 is a perspective view of a second direction detector, and FIG. 3 is a view taken along line m-m in FIG. Cross-sectional view, Figure 4 is No. 1111
5 is a vertical sectional side view of the windshield, FIG. 6 is a block diagram of the control system for spot visor control, FIG. 7 is a schematic flowchart of the spot visor control routine, and FIG. 8 is a schematic flowchart of the spot visor control routine. FIG. 3 is an explanatory diagram showing a light shielding part formed by spot visor control. ■...First direction detector, 6...First optical sensor, 8...
2nd direction detector, 13.. 2nd optical sensor, 15.. windshield, 18.. liquid crystal device, 19.. liquid crystal section, 20.. drive section, 22.. X electrode, 23.. Y
Electrode, 24...Liquid crystal, 29...Control device, 30...
CPU, 31・-ROM, 32・・R
AM, 34・35・-Detection signal input device.

Claims (1)

[Claims] (1) A liquid crystal device attached to a windshield, a first direction detector and a second direction detector that detect the direction of sunlight relative to the vehicle in two mutually orthogonal planes, and the first direction detector and a control means for receiving the detection signal from the second direction detector, determining the direction of the sunlight relative to the vehicle, and controlling the position of the light shielding part of the liquid crystal device according to the direction of the sunlight. Vehicle LCD spot visor.