JPH0350553Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a display device for a vehicle, and in particular, to a dynamically driven dot matrix liquid crystal display device for displaying various vehicle information, and to the dot matrix liquid crystal display device. viewing angle manual adjustment means for adjusting the viewing angle by adjusting the driving voltage of the vehicle, and wherein the liquid crystal display has a warning display means for displaying in red according to the content of the warning when a warning occurs. It is something.

[Conventional technology]

Conventionally, a liquid crystal display as shown in FIG. 8 has been used in this type of device. In the same figure, 20
is a twisted nematic TN type liquid crystal display element LCD, and deflection plates 21 are disposed on both sides thereof.
One deflection plate 21 is provided with a red color filter 22 and a light source 23 .

The basic configuration of the NT type LCD 20 for multiple display is shown in FIG. That is,
It has a structure in which liquid crystal molecules 28 are regularly arranged between two glass substrates 26 and 27 having transparent electrodes 24 and 25 inside, respectively. In addition, 29,
30 is an alignment film, 31 and 32 are passivation layers,
33 and 34 are polarizing plates, 35 is a spacer, 36 is a seal, 37 is an in-plane spacer, and 38 is a transfer.

In the above structure, an alternating voltage is applied between the transparent electrodes 24 and 25 to control the liquid crystal molecules, and display is performed using the change in the light transmittance of the LCD at this time. FIG. 10 shows the relationship between applied voltage and transmittance, and as the applied voltage increases, the transmittance increases.

The viewing angle of the LCD is determined by the alignment angle of the liquid crystal molecules, as shown in FIGS. 11a and 11b, where a shows the case where the applied voltage is low and the transmittance is low, and b shows the case where the applied voltage is high and the transmittance is high.

As mentioned above, LCDs have a viewing angle depending on the applied voltage, so from a position that deviates from the viewing angle,
When looking at the LCD display, the visibility of the displayed image becomes poor.

By the way, in a display device for a vehicle, for example, the line of sight for viewing the display changes depending on the driver's driving posture and the like. Therefore, when a display device consisting of an LCD with a viewing angle is installed in a vehicle, it is necessary to prevent the display from becoming unclear due to changes in the line of sight.

For example, in the case of a dot matrix liquid crystal display, it is necessary to increase the drive duty in order to increase the display capacity, but the higher the duty, the narrower the angular range for good visibility.

Therefore, as shown in FIG. 12, the voltage applied to the dot matrix liquid crystal display 39 has recently been changed by operating an adjustment knob 41 provided adjacent to the display screen 40, as shown in FIG. By adjusting the variable resistor VR so that the viewing angle of the liquid crystal display 39 is always within the angle range θ that allows good visibility for the driving vehicle, sufficient visibility can be achieved even when the duty of the liquid crystal display is high. make sure you get it,
Efforts are being made to increase display capacity.

That is, in FIG. 12, a power supply V _DD is applied to the liquid crystal display element 39, and a voltage at the reference potential level is applied to V _GND . V is temperature compensation circuit 42
Accordingly, an optimal voltage is applied to the display element 39 with respect to fluctuations in ambient temperature. This voltage V is a variable resistance
Connected to VR, the voltage of V _DD −V _O is the liquid crystal drive voltage.
V _OP (V _O is the voltage of the slider of the variable resistor VR).
Therefore, the driver operates the viewing angle adjustment knob 41 to vary the slider voltage V _O to set the angle θ.

[Problem that the invention attempts to solve]

However, in the conventional display device described above, it is necessary to set the optimum viewing angle to the optimum position each time the driver changes, and the operation is troublesome.

In addition, because a color filter is placed behind the liquid crystal display element, the brightness decreases, making it impossible to display warnings with sufficient brightness.Also, the background is red and black, and the warnings are displayed in red, making them difficult to read. , it was difficult to notice when a warning occurred, and there were also safety issues.

Therefore, in view of the above-mentioned conventional problems, the present invention allows the optimum viewing angle to be easily set to the optimum position even if the driver changes, and also allows the driver to receive a warning when a warning occurs. It is an object of the present invention to provide a vehicle display device that improves safety by increasing visibility so that the contents can be noticed quickly.

[Means for solving problems]

In order to achieve the above object, the vehicle display device according to the present invention has a plurality of drive voltage data corresponding to the drive voltage adjusted by the viewing angle manual adjustment means, and a saturated drive voltage corresponding to a predetermined saturation drive voltage. A storage means, for example, a memory, stores voltage data, and normally reads and outputs one selected from a plurality of drive voltage data stored in this storage means, and outputs the selected drive voltage data and saturation drive at the time of warning. The above-mentioned dot is provided with a readout means consisting of, for example, a CPU that alternately reads and outputs voltage data, and a drive voltage adjustment means that drives a dot matrix liquid crystal display of a dynamic drive partition plate based on the data outputted by the readout means. The warning display means of the matrix liquid crystal display is provided with a twisted nematic type liquid crystal display element and the opposite side of the display surface of this liquid crystal display element, and outputs red light in the direction of the red polarization axis, and is perpendicular to the red polarization axis. a bicolor polarization plate and a white light source that output light of other colors in the direction of the polarization axis, and a bicolor polarization plate and a white light source, which are provided on the display surface side of the twisted nematic liquid crystal display element and coincide with a polarization axis perpendicular to the red polarization axis. It is characterized by comprising a neutral deflection plate having a deflection axis.

[Effect]

With the above configuration, data on drive voltages for the dot matrix liquid crystal display adjusted by the manual viewing angle adjustment means can be stored in a plurality of storage means, so that voltages corresponding to a desired optimum viewing angle can be stored. Therefore, the driver can normally read out the stored data and apply it to the dot matrix liquid crystal display to obtain the optimum viewing angle.

Further, at the time of warning, the voltage corresponding to the desired optimum viewing angle and the saturation drive voltage are alternately read out and applied to the dot matrix liquid crystal display. As a result, due to the action of the bicolor polarizing plate and the neutral polarizing plate of the dot matrix liquid crystal display, when a voltage corresponding to the optimum viewing angle is applied, only the portion to which this voltage is applied is transmitted. When the saturation voltage is applied, the transmittance of the entire surface of the dot matrix liquid crystal display becomes sufficiently high and the entire surface becomes red. This is repeated alternately to complete flashing of the entire surface.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows its front part, and in the same figure, 1 is a liquid crystal display, which is composed of a liquid crystal display section 3 consisting of a blue display background section 2 and a red display lighting pixel 3. On the lower side of the display 1 are viewing angle adjustment buttons 4 and 5 for raising and lowering the viewing angle, a plurality of memory buttons 7 for storing the viewing angle, and a button for setting the memory button 7 to a storage mode. A set button 6 is provided.

FIG. 2 is a circuit block diagram of the display device according to the present invention, in which the CPU 8 receives data from the operations of the viewing angle adjustment buttons 4 and 5, the memory button 7, and the set button 6, the warning signal output at the time of warning, and the temperature. Detection data corresponding to the ambient temperature by the sensor 9 is input, and a digital signal corresponding to the drive voltage for the liquid crystal display 1 is outputted, and the viewing angle memory 10 is set to a writable state by operating the set button 7, and a predetermined value is set. The drive voltage data output at that time is stored in the memory 10 in accordance with the operation of the memory button 8. By operating this memory button 7, the data stored in the memory 10 is read out to the CPU 8 and output.
The data output from CPU8 is D/A converter 1
1 and converted into an analog signal. This analog signal is input to a liquid crystal drive voltage adjustment circuit 12, amplified to a predetermined level, and outputted from the adjustment circuit 12 as a drive voltage _VOP . The liquid crystal display 1 is driven by this drive voltage V _OP to perform display. The display device 1 is composed of a TN type dot matrix liquid crystal display element, and corresponds to the information display pixels shown in FIG.

The CPU 8 inputs the temperature detection data detected by the temperature sensor and performs temperature compensation processing so that the liquid crystal drive voltage becomes optimal. Further, when the memory button 7 is operated after the set button 6 is operated as described above, the data of the liquid crystal drive voltage corresponding to the viewing angle at this time is stored in the memory 10. Thereafter, when the memory button 7 is operated, the stored drive voltage data is read out by the CPU 8 and applied to the liquid crystal display 3 through the D/A converter 11 and the liquid crystal drive voltage adjustment circuit 12. Furthermore, the memory 10 stores data on the saturation voltage _VH of the liquid crystal display 3, which will be described later.

Next, the liquid crystal display 1 will be explained. In the configuration diagram shown in FIG. 3, 13 is a TN type liquid crystal element, and a neutral polarizing plate 14 is mounted on the display side surface.
and a light source 16 are provided. As shown in FIG. 4, the structure of the bicolor polarizing plate 14 includes a red polarizing layer 17 having a red polarizing axis in one direction, a blue polarizing axis 15 orthogonal to the red polarizing axis, and a blue polarizing layer 15 having a red polarizing axis in one direction. A blue polarizing layer 18 having a bicolor polarizing plate direction is disposed on the surface, and a protective layer 19 is formed on both sides thereof.

The operation of such a liquid crystal display 1 will be explained.
In FIG. 5, white light W is emitted from a light source 16 from one side of the red polarizing layer 17 of the bicolor polarizing plate 14. In FIG. The white light W has components in the X-axis direction coinciding with the red polarization axis and in the y-axis direction coinciding with the blue polarization axis direction. When the white light W passes through the red polarizing layer 17, it absorbs colors other than red among the white light components W in the absorption axis direction (x-axis direction), and only the red light R is allowed to pass through. Further, the white light W is allowed to pass through in the y-axis direction as is. This light is transmitted to the blue polarizing layer 1 of the bicolor polarizing plate 14.
However, among the white light components W in the absorption axis direction (y-axis direction), colors other than blue are absorbed, and only blue light B is allowed to pass through. Red light R remains in the x-axis direction
pass. As described above, the white light W from the light source 16 that has passed through the bicolor polarizing plate 14 is output as red light R in the direction of the red polarization axis (x-axis direction), and in the direction of the blue polarization axis (y-axis direction) orthogonal to the red polarization axis direction. Blue light B is output in the axial direction). This light is irradiated onto the TN type liquid crystal display element 13. When a driving voltage is not applied to the liquid crystal display element 13, the phases of the red light R and the blue light B are shifted by 90 degrees. That is, the blue light B is located in the x-axis direction, and the red light R is located in the y-axis direction. On the other hand, when a driving voltage is applied to the liquid crystal element 13, the light from the bicolor polarizing plate 14 passes through as is. The neutral polarizing plate 15 has an absorption axis in a direction that coincides with the blue polarization axis direction (y-axis direction) of the blue polarizing layer 18 in the bicolor polarizing plate 14, and absorbs all the light along the absorption axis and does not allow any light to pass through. . Therefore, when no drive voltage is applied to the liquid crystal display element 13, blue light B is output in the x-axis direction, and when a drive voltage is applied, red light R is output in the x-axis direction. Therefore, in normal times, only the background color is blue, and in the event of a warning, the pixels are displayed in red and the background color is blue.

Next, the driving voltage of the liquid crystal display element 13 will be explained. FIG. 6 shows the optical characteristics when the liquid crystal display element 13 is dynamically driven. In the figure, a indicates the optical characteristic when the pixel is selected, and b indicates the optical characteristic when the pixel is not selected. Normally, the liquid crystal display element 13 is sufficiently dark and turns off when the luminance has a transmittance of 10% or less, and a bright display is obtained when the luminance has a transmittance of 50% or more at the time of pixel selection, and the liquid crystal display element turns on. Therefore, the transmittance is 50%
Assuming that the voltage to obtain V is ₅₀ , the driving voltage when the transmittance is 10%, that is, the threshold voltage between the on state and the off state is
V _th , by setting the drive voltage V _OP in the range of V ₅₀ ≦V _OP ≦V _th , a display with good contrast without crosstalk can be obtained. Also, when not selected b
When a voltage equal to or higher than the threshold voltage V _th is applied, non-selected pixels are also turned on, causing crosstalk. The driving voltage (saturation voltage) when the characteristic b is saturated when not selected, that is, when the transmittance is 100% is
When V _H is applied, when a voltage equal to or higher than the saturation voltage V _H is applied, the liquid crystal molecules completely stand up, and light completely passes through both lit and non-lit pixels.

In the configuration of the present invention, the operation of the CPU 8 will be explained with reference to the flowchart shown in FIG.
As mentioned above, the memory 10 includes the liquid crystal display element 1.
It is assumed that the data of the saturation voltage V _H at No. 3 is stored in advance. First, it is determined whether the upward viewing angle adjustment switch 4 has been operated (a). If it is operated, upload the LCD drive voltage data (b). Next, it is determined whether the down viewing angle adjustment switch 5 has been operated (c). If it has been manipulated, lower the LCD drive voltage data (d). Next, it is determined whether the set switch 7 is being operated (e). Memory 1 if operated
The drive voltage data at that time is stored in the specified address of 0 (f). After each of the above operations, data on the liquid crystal drive voltage V _OP is output (g). Next, it is determined whether a warning signal has been input (h), and if so, display data of the warning content is output (i). Next, it is determined whether the liquid crystal display is flashing (j), and if it is not flashing, the following processing is performed to perform flashing. That is, first, data of the saturated liquid crystal drive voltage V _H is output (k). Next, it is determined whether this driving voltage V _H has elapsed for 1 second (l), and if it has elapsed, the data of the driving voltage V _OP in the on state (V ₅₀ ≦V _OP ≦V _th ) is output.
(m). Similarly, it is determined whether this driving voltage V _OP has passed for 1 second (n), and if it has elapsed, it is determined whether the above flushing operations k to n have been performed 5 times (o), and if it is within 5 times, it is determined (o). Return to process k and perform flushing.

Here, flashing is performed by applying two different voltages to the liquid crystal display element, but by applying the saturation voltage _VH , the liquid crystal/molecules stand up completely, increasing the light transmittance and causing flashing. Since the effectiveness is increased, a more powerful warning can be issued. Furthermore, since a bicolor polarizing plate is used, the light is not attenuated by a red color filter, and the flashing effect can be further enhanced. Furthermore, since the background color and the display pixel color can be displayed in completely different colors, visibility is improved.

[Effect of idea]

As explained above, according to the present invention, the driver can obtain the optimum viewing angle by simply reading out the voltage corresponding to the desired optimum viewing angle of the dot matrix liquid crystal display from a plurality of stored driving voltages. To easily set the optimum viewing angle to the optimum position even if the person changes.

In addition, at the time of a warning, the warning display is displayed in red on a background of other colors, and the entire red display is repeated, and flashing is performed on the entire surface, so the driver can quickly understand the occurrence of the warning and its contents. It is possible to raise awareness and improve safety by increasing visibility.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the front side of a display device according to the present invention, Figure 2 is a block diagram showing the circuit configuration of the present invention, and Figure 3 is a diagram showing the configuration of the liquid crystal display shown in Figures 1 and 2. 4 is a diagram showing the configuration of the bicolor polarizing plate in FIG. 3, FIG. 5 is a diagram for explaining the operation of the liquid crystal display in FIG. 3, and FIG. 6 is a diagram showing the optical characteristics of the liquid crystal display. Figure 7 is a flowchart showing the processing of the CPU in Figure 2, Figure 8 is a diagram showing the configuration of a conventional liquid crystal display, and Figure 9 is a diagram showing the configuration of a twisted nematic type liquid crystal display. 10 are diagrams showing the optical characteristics of a liquid crystal display, FIGS. 11a and 11b are diagrams for explaining the viewing angle of a liquid crystal display, and FIG. 12 is a diagram showing viewing angle adjustment means in a conventional display device. , FIG. 13 is a diagram showing a conventional vehicle display device equipped with the means shown in FIG. 12. 1...Liquid crystal display, 4, 5...Viewing angle adjustment button, 6
...Set button, 7...Memory button, 8...CPU,
10...Memory, 13...TN type liquid crystal element, 14
...Bicolor polarizing plate, 15... Neutral polarizing plate, 16... Light source, 17... Red polarizing layer, 18...
...Blue polarizing layer.

Claims (1)

[Scope of Claim for Utility Model Registration] A dynamically driven dot matrix liquid crystal display that displays various vehicle information, and a manual viewing angle adjustment means for adjusting the viewing angle by adjusting the driving voltage of the dot matrix liquid crystal display. and a warning display means for displaying a warning in red according to the content of the warning when the liquid crystal display generates a warning, wherein a plurality of warning display means corresponding to the drive voltage adjusted by the viewing angle manual adjustment means are provided. a storage means for storing driving voltage data and saturated driving voltage data corresponding to a predetermined saturated driving voltage; and a storage means for normally reading and outputting one selected from a plurality of driving voltage data stored in the storage means. ,
reading means for alternately reading and outputting the selected driving voltage data and the saturation driving voltage data at the time of warning; and a liquid crystal driving voltage for outputting a driving voltage for driving the liquid crystal display based on the data output by the reading means. an adjustment means, the warning display means of the liquid crystal display is provided on a side opposite to the twisted nematic type liquid crystal display element and the display surface of the liquid crystal display element, and outputs red light in the direction of the red polarization axis; a bicolor polarization plate and a white light source that output light of another color in a direction of a polarization axis perpendicular to the red polarization axis; and a white light source provided on the display surface side of the liquid crystal display element;
A vehicle display device comprising: a neutral deflection plate having a deflection axis that coincides with a deflection axis perpendicular to the red deflection axis.