JPH0728024A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To change display color of the part corresponding to the same segment electrodes to plural colors although this device uses liquid crystal cells of a segment display type while coloring transmitted light without using, a color filter, thereby making it possible to increase transmittance of light and to sufficiently enhance the brightness of display. CONSTITUTION:This color liquid crystal display device is constituted by arranging a pair of polarizing plates 31, 32 so as to hold the liquid crystal cell 20 of the segment display type therebetween and respectively shifting the orientation directions of the liquid crystal molecules on both substrate 21, 22 sides of the liquid crystal cell 20 diagonally at a prescribed angle with the transmission axes of a pair of these polarizing plates 31, 32. The device has a liquid crystal display 10 which is changed in the display colors of the parts corresponding to the respective segment electrodes 24 of the liquid crystal cell 20 to the plural colors according to applied voltages and a display driving circuit 40 for applying a driving voltage to selectively display the plural colors between the common electrode 23 and respective segment electrodes 24 of the liquid crystal cell 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device capable of obtaining a colored display.

[0002]

2. Description of the Related Art Conventionally, as a color liquid crystal display device capable of obtaining a colored display, one which colors transmitted light by using a color filter has been used. This color liquid crystal display device is composed of a liquid crystal display body including a liquid crystal cell having a color filter and a pair of polarizing plates arranged to sandwich the liquid crystal cell, and a display driving means for driving the liquid crystal cell. ing.

[0003]

However, in the above-mentioned conventional color liquid crystal display device, since the liquid crystal display body colors the transmitted light by using the color filter, the light transmittance is low and therefore the display is dark. I have a problem.

This is due to the absorption of light by the color filter. Since the color filter also absorbs light in the wavelength band corresponding to the color with a considerably high absorptivity, the colored light passing through the color filter is The light has a significantly reduced amount of light as compared with the light in the wavelength band before entering the color filter, and the display becomes dark.

Although the liquid crystal display body in the conventional color liquid crystal display device is of a transmissive type, if a reflection plate is arranged on the back surface of the liquid crystal display body to make it a reflective type, the liquid crystal display body is exposed from the front side. The light that enters, is reflected by the reflecting plate on the back surface, and goes out to the front surface side passes twice through the color filter, and the amount of light is doubly reduced, so that the display becomes considerably dark and almost unusable as a display device.

Moreover, in the above-mentioned conventional color liquid crystal display device, the display color at each location where the electrodes of both substrates of the liquid crystal cell face each other is determined by the color of the color filter provided at this location, so the same location Only one color could be displayed.

In the liquid crystal display device, a plurality of segment electrodes are formed on one of a pair of transparent substrates facing each other with a liquid crystal layer in between, and a common electrode facing the segment electrodes is formed on the other transparent substrate. There are a segment display type liquid crystal cell and a simple matrix type or active matrix type dot display type liquid crystal cell. In the case of a color liquid crystal display device using a dot display type liquid crystal cell, Although the color of a pixel is determined by the color of the color filter corresponding to that pixel, it is also possible to display a mixed color of the colors of these pixels by alternately arranging the pixels of a plurality of colors (generally red, green, and blue). However, in the color liquid crystal display device using the segment display type liquid crystal cell, the display color of the portion corresponding to the same segment electrode is only one color.

According to the present invention, the transmitted light can be colored to increase the light transmittance without using a color filter so that the brightness of the display can be sufficiently increased, and the segment display type liquid crystal cell is used. However, it is an object of the present invention to provide a color liquid crystal display device capable of changing the display color of a portion corresponding to the same segment electrode to a plurality of colors.

[0009]

In a color liquid crystal display device of the present invention, a liquid crystal cell is provided between a transparent substrate having a plurality of segment electrodes and a transparent substrate having a common electrode facing the segment electrodes. According to a first aspect of the present invention, a pair of polarizing plates are arranged with the segment display type liquid crystal cell sandwiched therebetween, and liquid crystal on both substrate sides of the liquid crystal cell is used. The orientation directions of the molecules are slanted by a predetermined angle with respect to the transmission axes of the pair of polarizing plates, and a plurality of display colors of a portion corresponding to each segment electrode of the liquid crystal cell is formed according to a voltage applied to the liquid crystal cell. A liquid crystal display body that changes to a different color, and a display driver that applies a drive voltage for selectively displaying the plurality of colors between the common electrode of the liquid crystal cell and each segment electrode. It is characterized in that it comprises and.

According to a second aspect of the present invention, a polarizing plate is arranged on the front surface side of the segment display type liquid crystal cell, a reflector is arranged on the rear surface side of the liquid crystal cell, and both the substrate sides of the liquid crystal cell are arranged. The alignment directions of the liquid crystal molecules are each shifted obliquely by a predetermined angle with respect to the transmission axis of the polarizing plate, and the display color of the portion corresponding to each segment electrode of the liquid crystal cell is set in accordance with the voltage applied to the liquid crystal cell. A liquid crystal display body that changes to a color, a liquid crystal display body that changes a display color of a portion corresponding to each segment electrode of the liquid crystal cell into a plurality of colors according to a voltage applied to the liquid crystal cell, and a common of the liquid crystal cells. A display driving means for applying a driving voltage for selectively displaying the plurality of colors is provided between the electrode and each segment electrode.

In the first and second aspects of the invention, the liquid crystal cell may be one in which the liquid crystal molecules are homogeneously aligned, or one in which the liquid crystal molecules are twisted between the two substrates.

[0012]

In the color liquid crystal display device of the present invention, the liquid crystal display body is caused to perform the colored display by the polarization action of the liquid crystal cell, and the liquid crystal cell of the liquid crystal display body is driven by the display driving means to thereby display the liquid crystal display. The display color of the body is changed to a plurality of colors.

That is, in the liquid crystal display in the color liquid crystal display device according to the first aspect of the present invention, the linearly polarized light that has entered the liquid crystal cell through one of the polarizing plates is polarized by the polarizing action in the process of passing through the liquid crystal cell. Since the light is changed to enter the other polarizing plate, only the light of the wavelength of the polarization component that passes through the other polarizing plate out of the light passes through the polarizing plate and becomes colored light.

In the liquid crystal cell, the alignment state of the liquid crystal molecules changes according to the voltage applied between the electrodes of both substrates, so that the liquid crystal cell exhibits different polarization effects depending on the alignment state of the liquid crystal molecules. .

For this reason, the light polarized by the liquid crystal cell becomes light having a different polarization state depending on the alignment state of the liquid crystal molecules of the liquid crystal cell and enters the other polarizing plate, so that it corresponds to each segment electrode of the liquid crystal cell. The display color of the portion to be changed changes into a plurality of colors according to the voltage applied between the common electrode and the segment electrode.

That is, this liquid crystal display body colors transmitted light without using a color filter. Therefore, the amount of colored light is the wavelength band of the light incident on the liquid crystal display body, which is the colored light. Since the amount of light is almost the same as the amount of light, the light transmittance can be increased and the brightness of the display can be made sufficiently high.

In the color liquid crystal display device according to the first aspect of the invention, a driving voltage for selectively displaying a plurality of colors is applied between the common electrode and each segment electrode of the liquid crystal cell of the liquid crystal display. The display color of the portion corresponding to the same segment electrode can be changed to a plurality of colors because it is driven by the display driving means.

Further, the liquid crystal display in the color liquid crystal display device of the second invention is of a reflection type in which light incident from the front surface side is reflected by the reflection plate on the rear surface side and displayed. The incident light of (2) passes through the polarizing plate and the liquid crystal cell, is reflected by the reflecting plate, and is emitted again through the liquid crystal cell and the polarizing plate.

In this liquid crystal display, linearly polarized light that has entered through the polarizing plate is changed in its polarization state by its polarizing action in the process of passing through the liquid crystal cell, and is reflected by the reflection plate to be again reflected in the liquid crystal cell. Since the polarization state can be changed again in the process of passing through the liquid crystal, the light that enters the polarizing plate again through the liquid crystal cell is the light that has been polarized twice by the liquid crystal cell. Only the light having the wavelength of the polarized component is transmitted through the polarizing plate and emitted, and the emitted light becomes colored light.

Also in this liquid crystal display, since the light that has been polarized by the liquid crystal cell twice has a different polarization state depending on the alignment state of the liquid crystal molecules of the liquid crystal cell, the light enters the polarizing plate. The display color of the portion corresponding to each segment electrode of the cell changes to a plurality of colors according to the voltage applied between the common electrode and the segment electrode.

That is, this liquid crystal display body also colors transmitted light without using a color filter, like the liquid crystal display body in the first aspect of the present invention. Therefore, the amount of colored light is different from that of the liquid crystal display body. Since the amount of light in the wavelength band that becomes the colored light in the incident light is almost the same, the light transmittance can be increased and the brightness of the display can be sufficiently increased.

Also, in the color liquid crystal display device according to the second aspect of the invention, a driving voltage for selectively displaying a plurality of colors is applied between the common electrode and each segment electrode of the liquid crystal cell of the liquid crystal display. The display color of the portion corresponding to the same segment electrode can be changed to a plurality of colors because it is driven by the display driving means.

[0023]

【Example】

[First Embodiment of the First Invention] A first embodiment of the first invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a color liquid crystal display device. The color liquid crystal display device includes a liquid crystal display body 10 and a display drive circuit 40 thereof.

First, the liquid crystal display 10 will be described.
The liquid crystal display 10 has a configuration in which a pair of polarizing plates 31 and 32 are arranged with a liquid crystal cell 20 in between. In addition,
The liquid crystal display 10 of this embodiment is of a reflection type, and a reflection plate 33 is arranged on the back surface (lower surface of the lower polarization plate 32) thereof.

The liquid crystal cell 20 includes transparent electrodes 23 and 24.
And a pair of upper and lower transparent substrates 21 and 22 on which the alignment films 25 and 26 are formed are bonded to each other via a frame-shaped sealing material 27, and surrounded by the sealing material 27 between the two substrates 21 and 22. The liquid crystal 28 is sealed in the open region.

The liquid crystal cell 20 is of a segment display type which is driven in a time division manner. The transparent electrode 23 formed on the upper substrate 21 is a common electrode divided into a plurality of pieces, and the transparent electrode formed on the lower substrate 22. The electrodes 24 are a plurality of segment electrodes having a shape corresponding to the display pattern.

The liquid crystal cell 20 is one in which liquid crystal molecules are homogeneously aligned in one direction, and the pair of polarizing plates 31 and 32 have their transmission axes respectively on both substrates 21 and 22 of the liquid crystal cell 20. It is arranged so as to be slanted at a predetermined angle with respect to the alignment direction of the liquid crystal molecules on the side.

FIG. 2 is a plan view showing the alignment direction of liquid crystal molecules of the liquid crystal cell 20 and the transmission axes of the pair of polarizing plates 31 and 32. In FIG. 2, a is the alignment direction of the liquid crystal molecules of the liquid crystal cell 20, and since the liquid crystal cells 20 are homogeneously aligned, the alignment directions of the liquid crystal molecules on both substrates 21 and 22 are the same. is there.

Further, in FIG. 2, 31a is the upper polarizing plate 3.
1 is a transmission axis, and 32a is a transmission axis of the lower polarizing plate 32. In this embodiment, the transmission axes 31a, 3 of both polarizing plates 31, 32 are provided.
2a are parallel to each other, and the transmission axes 31a and 32 are obliquely intersected with the liquid crystal molecule alignment direction (homogeneous alignment direction) a of the liquid crystal cell 20 at the same deviation angle ψ. In this embodiment, the deviation angle ψ between the liquid crystal molecule alignment direction a of the liquid crystal cell 20 and the transmission axes 31a and 32a of the polarizing plates 31 and 32 is 45 °.

The liquid crystal display 10 is for displaying the light (natural light or light from the illumination light source) incident from the front surface side by reflecting it on the rear surface side reflection plate 33, and the incident light from the front surface side is displayed. The light passes through the upper polarizing plate 31, the liquid crystal cell 20, and the lower polarizing plate 32, is reflected by the reflection plate 33, and again passes through the lower polarizing plate 32, the liquid crystal cell 20, and the upper polarizing plate 31, and is emitted.

In the liquid crystal display 10, since the linearly polarized light that has entered through the upper polarizing plate 31 is changed in its polarization state due to its polarization action while passing through the liquid crystal cell 20, it enters the lower polarizing plate 32. Of the light, the lower polarizing plate 3
Only the light of the wavelength of the polarization component that transmits 2 passes through the lower polarizing plate 32.
To become colored light.

The liquid crystal cell 20 has two substrates 2
Since a polarization effect is exhibited in response to a change in the alignment state of the liquid crystal molecules due to the voltage application between the electrodes 23 and 24 of the electrodes 1 and 22, the polarization state of the light that enters the lower polarizing plate 32 through the liquid crystal cell 20 is the liquid crystal. Depending on the liquid crystal molecule alignment state of the cell 20,
Therefore, the display color changes into a plurality of colors according to the voltage applied to the liquid crystal cell 20.

The coloration of the light will be described in detail. The liquid crystal cell 20 has a polarization effect similar to that of a retardation plate having a slow axis in the long axis direction of the liquid crystal molecules when the liquid crystal molecules are homogeneously aligned. Show.

Since the liquid crystal molecule alignment direction (homogeneous alignment direction) of the liquid crystal cell 20 and the transmission axis 31a of the upper polarizing plate 31 obliquely intersect with each other at the shift angle ψ (here, ψ = 45 °). In the state where no voltage is applied between the electrodes 23 and 24 of the liquid crystal cell 20 (the state where the liquid crystal molecules are homogeneously aligned), the light linearly polarized by the upper polarizing plate 31 and incident on the liquid crystal cell 20 is In the process of passing through the cell 20, it is subjected to a polarization action according to the value of its Δn · d (the product of the liquid crystal birefringence phase difference Δn and the liquid crystal layer thickness d) to become elliptically polarized light.

Therefore, at this time, of the elliptically polarized light that is emitted from the liquid crystal cell 20 and is incident on the lower polarizing plate 32, only the wavelength light of the polarization component that is transmitted through the lower polarizing plate 32 is transmitted through this lower polarizing plate 32. Therefore, the light (linearly polarized light) that has passed through the lower polarizing plate 32 becomes colored light.

On the other hand, when a voltage is applied between the electrodes 23 and 24 of the liquid crystal cell 20, as the liquid crystal molecules of the liquid crystal cell 20 rise and align with respect to the surfaces of the substrates 21 and 22, the birefringence potential of the liquid crystal is increased. Since the phase difference Δn becomes small, the liquid crystal cell 20
Since the value of Δn · d becomes smaller, the polarization effect in the liquid crystal cell 20 becomes smaller.

When the polarization action of the liquid crystal cell 20 changes, the polarization state of the elliptically polarized light that exits the liquid crystal cell 20 and enters the lower polarization plate 32 changes, so that the color of the colored light passing through the lower polarization plate 32 changes. Changes.

When the liquid crystal molecules of the liquid crystal cell 20 are vertically oriented and oriented, Δn = 0 and the polarization action in the liquid crystal cell 20 becomes “0”. At that time, the upper polarizing plate 31
Since the light linearly polarized by and incident on the liquid crystal cell 20 passes through the liquid crystal cell 20 in its polarization state (linearly polarized light), at this time, the liquid crystal cell 20 is emitted and the lower polarizing plate 32
The linearly polarized light incident on is transmitted through the lower polarizing plate 32 without being absorbed by the lower polarizing plate 32, and the light emitted from the lower polarizing plate 32 becomes uncolored light.

The colored light that has passed through the lower polarizing plate 32 is reflected by the reflection plate 33 and is emitted to the upper surface side of the liquid crystal display body 10 through a path opposite to the above-described optical path. Is displayed.

In this case, the colored light reflected by the reflection plate 33 is only the wavelength light of the polarization component that has passed through the lower polarization plate 32 of the light that has been elliptically polarized by the polarization action of the liquid crystal cell 20 described above. Therefore, most of the colored light reflected by the reflecting plate 33 passes through the liquid crystal cell 20 without being polarized, but the light of a very small wavelength component at the end of the wavelength range is transmitted through the liquid crystal cell 20. Since the colored light that is polarized in the process of passing and is absorbed by the upper polarizing plate 31, the colored light that passes through the upper polarizing plate 31 and is emitted has a color purity higher than that of the colored light reflected by the reflecting plate 33. Become.

As described above, the liquid crystal display body 10 colors the transmitted light without using a color filter. Therefore, the amount of the colored light is the amount of the colored light out of the light incident on the liquid crystal display body 10. Since it is almost the same as the amount of light in the wavelength band, the transmittance of light can be increased and the brightness of the display can be sufficiently increased.

That is, since the liquid crystal display body used in the conventional color liquid crystal display device colors the transmitted light by the color filter, it has a wavelength band of the colored light of the light incident on the display device. Although the amount of colored light that has passed through the color filter is considerably reduced compared to the amount of light, such a reduction in the amount of light hardly occurs in the liquid crystal display 10 of the above embodiment.

For this reason, although the liquid crystal display 10 is of a reflective type, its display brightness is sufficient, and is much higher than that of the liquid crystal display used in the conventional color liquid crystal display device. A bright colored display can be obtained.

Further, in the liquid crystal display used in the conventional color liquid crystal display device, the display color at each position where the electrodes of both substrates of the liquid crystal cell face each other depends on the color of the color filter provided at this position. Therefore, the display color of the same portion, that is, the portion corresponding to the same segment electrode is only one color. However, in the liquid crystal display 10, since the polarization action of the liquid crystal cell 20 changes depending on the alignment state of the liquid crystal molecules, the Changes depending on the voltage applied to the liquid crystal cell 20.

The display color of the liquid crystal display 10 is determined by the value of Δnd of the liquid crystal cell 20 and the shift angle ψ between the transmission axis 31a of the upper polarizing plate 31 and the liquid crystal molecule orientation direction a of the liquid crystal cell 20. .

As an example, Δn of the liquid crystal cell 20 is
D is 1.1 μm, and the shift angle ψ between the transmission axis 31a of the upper polarizing plate 31 and the liquid crystal molecule alignment direction a of the liquid crystal cell 20 is 45 °.
When the transmission axis 32a of the lower polarizing plate 32 is parallel to the transmission axis 31a of the upper polarizing plate 31, the display color when the liquid crystal molecules of the liquid crystal cell 20 are in the initial homogeneous alignment state is "green". , In the process of the liquid crystal molecules rising and aligning,
"Purple", "Yellow", "Blue" with high light intensity and high color purity
Is displayed.

The following [Table 1] shows the relationship between the voltage applied to the liquid crystal cell 20 of the liquid crystal display 10 and the display color. In addition, in this [Table 1], the value of the applied voltage is an effective voltage value applied between the electrodes 23 and 34 of the liquid crystal cell 20.

[0048]

[Table 1]

Although not shown in this [Table 1],
The display color is "white" (no color) when a voltage is applied to the liquid crystal cell 20 so that the liquid crystal molecules rise and align almost vertically.
On the other hand, the display drive circuit 40 shown in FIG. 1 drives the liquid crystal cell 20 of the liquid crystal display body 10, and the common electrodes 23 and the segment electrodes 24 of the liquid crystal cell 20 perform display drive at their terminal portions. It is connected to the circuit 40.

The display drive circuit 40 applies a drive voltage for selectively displaying the plurality of colors between the common electrodes 23 and the segment electrodes 24 of the liquid crystal cell 20, and is supplied from an external circuit. The liquid crystal cell 20 is driven according to the display data signal and the color selection signal.

For example, when the display colors of the liquid crystal display 10 are the four colors of green, purple, yellow and blue shown in [Table 1] above,
The display drive circuit 40 selectively applies four drive voltages V1, V2, V3, and V4 shown in [Table 1] between each common electrode 23 and each segment electrode 24 of the liquid crystal cell 20. To do.

That is, in the color liquid crystal display device, the liquid crystal cell 20 of the liquid crystal display body 10 is replaced by the common electrode 2 thereof.
3 and each segment electrode 24 are driven by applying a drive voltage for selectively displaying a plurality of colors. According to this color liquid crystal display device, the same segment electrode 2 is used.
The display color of the portion corresponding to 4 can be changed to a plurality of colors.

A concrete display example of the color liquid crystal display device will be described. FIGS. 3 to 7 show examples in which the color liquid crystal display device is applied to a calculator (electronic desk calculator). FIG. 3 is a diagram showing the shape of the segment electrode 24 formed on one substrate 22 of the liquid crystal cell 20, FIGS. 4 to 6 are diagrams showing a display state when a calculator is used, and FIG. 7 is a block showing a circuit configuration of the calculator. It is a figure.

First, the segment electrode 24 formed on the one substrate 22 of the liquid crystal cell 20 will be described. As the segment electrode 24, as shown in FIG. A "-" (minus) display electrode b and an "E" (error) display electrode c are formed.

This calculator displays an 8-digit numerical value, "-" when the numerical value is a negative value, and "E" when there is an error. Are displayed in different colors as shown in FIGS.

This display example is an example in which the voltage applied to the liquid crystal cell 20 of the liquid crystal display 10 and the display color are in the relationship of [Table 1], and the segment electrode 24 is not formed in a region (voltage). The display color of the area where no voltage is applied is always "green", and the voltage value (effective value) between the common electrode 23 and the segment electrode 24 is 1.0 v or less in the portion corresponding to each segment electrode 24. The display color of the portion to which the drive voltage V1 of is applied is also "green".

When the display data has a positive (+) numerical value and there is no error, this calculator has a numerical value (1,234.5 in the drawing) in the background of "green" as shown in FIG.
678) is displayed in “yellow” and the display data is a negative (−) numerical value, as shown in FIG. 5, “−” is displayed in the background color of “green” (12.3456 in the figure). ) And are displayed in "purple". If there is an error, "E" and "0" for eight digits are displayed in "blue" in the "green" background color, as shown in FIG.

That is, the calculator performs display in different colors depending on whether the display data has a positive numerical value, the display data has a negative numerical value, or an error has occurred. According to this calculator, the positive / negative of the display data and the error can be clearly recognized without overlooking, as compared with the one having only one display color.

Next, the circuit configuration of the calculator for performing the above display will be described. The circuit of this calculator is shown in Fig. 7.
As shown in FIG. 5, a display data signal for displaying a calculation result and the like, and a display data signal for performing a calculation process based on a numerical value and a calculation command input by operating the input key 58 from the key input unit 57 and a state such as an error. And a color control section 60 for receiving a status signal from the calculator circuit section 50 and outputting a color selection signal for selecting a display color, and the calculator circuit section. A display data signal from 50 and the color control unit 60
The display drive circuit 40 receives the color selection signal output from the display drive circuit 40 and drives the liquid crystal cell 20, and the power supply 59 supplies power to the display drive circuit 40.

The calculator circuit section 50 has the same structure as the circuit section of a general calculator, and controls arithmetic operations, storage, display data output, etc. in response to input numerical values and arithmetic commands from the key input section 57. Control circuit 51 to be executed and this control circuit 5
An arithmetic circuit 52 for performing arithmetic processing of numerical values and the like by a command from 1, a storage circuit 53 for storing arithmetic results and the like, an input numerical value from the key input unit 57 and data such as arithmetic results calculated by the arithmetic circuit 52. And a display signal generating circuit 54 for generating a display data signal for displaying.

Further, the calculator circuit section 50 detects a negative sign detection circuit 56 for detecting a negative sign (negative carry) of the above operation result, and an error such as an inputted numerical value and operation command or the operation result. An error detection circuit 57 and a negative sign detection circuit 56 and an error detection circuit 57 are provided.
The state detection signals from the above are output to the display signal generating circuit 54 and the color control unit 60, respectively.

The color control section 60 is composed of a color selection signal generating circuit 61 for selecting a display color which is predetermined for each state, and the states from the negative sign detecting circuit 56 and the error detecting circuit 57. A color selection signal for selecting a display color corresponding to the detection signal is generated.

On the other hand, the display drive circuit 40 receives the display data signal output from the display signal generation circuit 54 of the calculator circuit section 50 and the color selection signal from the color selection signal generation circuit 61, and receives the liquid crystal cell 20. On each segment electrode 24 of
A segment voltage corresponding to a predetermined display color determined by the display data signal and the color selection signal is supplied, and a common voltage for time-divisionally driving the liquid crystal cell 20 with a predetermined duty is supplied to each common electrode 23. To do.

This display drive circuit 40 has a plurality of drive voltages corresponding to respective display colors (purple, yellow, blue) other than the background color (green), that is, V2, V3, V in the above [Table 1].
Of the driving voltage generating circuit 41 for generating 4 and the driving voltage corresponding to the selected display color among the driving voltages V2 to V4 generated by the driving voltage generating circuit 41 from the color selecting signal generating circuit 61. Each segment electrode 24 of the liquid crystal cell 20 based on the drive voltage selection circuit 42 selected by the selection signal, the display signal from the display signal generation circuit 54, and the selection drive voltage supplied from the drive voltage selection circuit 42.
And a drive waveform forming circuit 43 that forms a waveform of a segment voltage supplied to the common electrode 24 and a waveform of a common voltage supplied to each common electrode 24.

In the calculator circuit section 50, the numerical value and the operation command input from the key input section 57 are sent to the control circuit 51, and the control circuit 51 causes the operation circuit 52 to calculate the numerical value in accordance with the operation command. The calculation result is stored in the memory circuit 53 and the calculation result data is sent to the display signal generating circuit 54.

The arithmetic circuit 52 outputs a negative carry to the negative sign generating circuit 55 when the operation result becomes a negative value, and the negative sign generating circuit 55 displays the negative sign for displaying "-". The detection signal is sent to the display signal generation circuit 54 and the color control unit 6.
0 to the color selection signal generation circuit 61.

Further, the control circuit 51 outputs an error signal to the error detection circuit 56 when an error such as a digit overrun of the input numerical value or a digit overrun of the operation command and the operation result occurs, and the error detection circuit 56. Is an error detection signal for displaying an error,
4 and the color selection signal generating circuit 61 of the color control unit 60.

The display signal generating circuit 54 includes the control circuit 5
The display data sent from 1 and the presence or absence of the negative code detection signal from the negative code generation circuit 55 and the error detection signal from the error detection circuit 56 form a display data signal corresponding to the display pattern at that time, This display data signal is output to the drive waveform forming circuit 43 of the display drive circuit 40.

Further, the color selection signal generation circuit 61 of the color control unit 60 generates a color selection signal corresponding to a normal display color (yellow) in a state where neither the negative sign detection signal nor the error detection signal is input, and the negative sign. When a detection signal is input, a color selection signal corresponding to the negative display color (purple) is generated, and when an error detection signal is input, the display color when an error occurs (blue)
A color selection signal corresponding to is generated and the color selection signal is output to the drive voltage selection circuit 42 of the display drive circuit 40.

On the other hand, the drive voltage generation circuit 41 of the display drive circuit 40 has a voltage required for forming the drive waveform of the liquid crystal cell 20 from the voltage of the power supply 59 and a plurality of different voltages V2 corresponding to the display colors of the respective colors. , V3, V4,
These voltages are supplied to the drive voltage selection circuit 42.

Then, the drive voltage selection circuit 42 responds to the color selection signal from the color selection signal generation circuit 61 by the voltage corresponding to the selected display color among the plurality of voltages supplied from the drive voltage generation circuit 41. Is selected, and the voltage is supplied to the drive waveform forming circuit 43.

The drive waveform forming circuit 43 is used for the liquid crystal cell 2
A plurality of common voltages for time-divisionally driving 0 at a predetermined duty (for example, 1/3 duty), and the liquid crystal cell 20.
To generate a plurality of segment voltages for performing display according to the display data signal from the display signal generating circuit 54, and the common voltage and the segment voltage are used as the common electrodes 23 and the segment electrodes 24 of the liquid crystal cell 20. And to supply respectively.

The common voltage supplied to each common electrode 23 is a voltage having a waveform in which the selection periods are shifted from each other. The segment voltage supplied to each segment electrode 24 is a voltage of a waveform to which an ON voltage or an OFF voltage is applied in synchronization with the selection period of the common electrode 23 facing the segment electrode 24, and the ON voltage is
The effective voltage between the common electrode 23 and the segment electrode 24 is the drive voltage selection circuit 4 based on the display data signal.
Selected voltage V2, V3, or V4 supplied from 2, that is, a voltage whose display color is green, yellow, or red,
The OFF voltage is a voltage at which the effective voltage between the common electrode 23 and the segment electrode 24 is V1 in the above [Table 1], that is, the display color is the background color (green). This OFF voltage is preset in the drive waveform forming circuit 43.

When the common voltage and the segment voltage are supplied to the liquid crystal cell 20, the common voltage having a waveform with a different selection period is applied to each common electrode 23, and each segment electrode 24 responds to the display data signal. The segment voltage is applied to drive the liquid crystal cell 20 in a time division manner, and the liquid crystal display 10 displays the display patterns shown in FIGS. 4 to 6 according to the display data signal.

In the above example, when the display data is a positive (+) numerical value and there is no error, all the display patterns are displayed in "yellow", and the display data is a negative (-) numerical value. Displays all display patterns in "purple", and displays all display patterns in "blue" if there is an error, but the relationship between each of these states and display colors can be selected arbitrarily, Further, when the display drive circuit 40 is configured to control the voltage value of the segment voltage supplied to each segment electrode 24 for each segment voltage, for example, when the display data is a negative (-) numerical value, "green" is displayed. It is also possible to display a combination of a plurality of colors, such as displaying "-" in "purple" and numerical values in "yellow" in the background color of "".

8 to 13 show an example in which the color liquid crystal display device described above is applied to an electronic timepiece having an alarm function. FIG. 8 shows the shape of the segment electrode 24 formed on one substrate 22 of the liquid crystal cell 20. 9 and 13 are views showing the display state of the timepiece.

First, the segment electrode 24 formed on the one substrate 22 of the liquid crystal cell 20 will be described. As the segment electrode 24, as shown in FIG. 8, a time display electrode d and an alarm mark display electrode are provided. e are formed.

The electronic timepiece normally displays the time, displays the time and the alarm mark when the alarm is set, and further displays the time when the remaining time up to the alarm set time is less than the predetermined time. It also has a function to notify the remaining time by changing the display color of the alarm mark.

The display in each of these states is as follows.
Note that this display example is also an example in the case where the voltage applied to the liquid crystal cell 20 of the liquid crystal display 10 and the display color have the relationship of [Table 1] above, and thus the background color is “green”.

FIG. 9 shows a normal display state, in which the time (“AM10: 43” in the figure) is displayed in “yellow”. Further, FIG. 10 shows a display state when the alarm is set. At this time,
In addition to the time displayed in "yellow", the alarm mark is displayed in "blue".

This electronic timepiece has a time remaining of 30 minutes or less before the alarm setting time, a time remaining of 10 minutes or less, and an alarm setting time. Change the display color.

This will be explained by taking the case where an alarm is set at "PM 3:00" as an example. The display until the time of the clock reaches the alarm set time is as shown in FIG. When the remaining time becomes 30 minutes or less, as shown in FIG. 11, (“PM2:
30 "), the color of both the time and the alarm mark becomes" blue ".

When the remaining time is 10 minutes or less, as shown in FIG. 12 (“PM2: 50” in the figure), the color of the alarm mark remains “green” and the color of the time becomes “purple”. , And the time is the alarm set time "PM3:
At "00", both the color of the time and the alarm mark become "purple" as shown in FIG.

The alarm is activated when the alarm set time is reached. Also, the alarm operation and the display color when the alarm set time is reached will continue until a fixed time (for example, 5 minutes) has passed or until an alarm release operation is performed, after which the alarm will stop and display at the same time. The color returns to the normal display color (yellow).

14 to 19 show an example in which the above-mentioned color liquid crystal display device is applied to a radio receiver having a clock function and a channel memory function, and FIG. 14 is formed on one substrate 22 of the liquid crystal cell 20. FIGS. 15 to 19 are views showing the shape of the segment electrode 24 formed, and FIGS. 15 to 19 are views showing the display state of the display unit of the receiver.

First, the segment electrode 24 formed on one substrate 22 of the liquid crystal cell 20 will be described. As the segment electrode 24, as shown in FIG. 14, an electrode f for displaying time and a reception frequency is used. , FM broadcast tuning display electrode g, electrode h used for both AM broadcast tuning display and clock AM (am) display, and clock PM
(PM) A display electrode i and a registration operation display electrode j for displaying the frequency registration operation state in the channel memory are formed. In this example, the registration operation display electrode j is an electrode for displaying the character "MEMORY" in white characters (the color of the white characters is the background color).

This radio receiver displays the time on the display section when it is not used as a receiver, and displays the reception frequency on the display section when it is used as a receiver. Further, this radio receiver is provided with a channel memory for storing a desired reception frequency, and when the reception frequency is registered in the channel memory, "MEMORY" indicating the registration operation state is displayed on the display unit. , Displays the frequency to be stored in the channel memory.

The display in each of these states is as follows.
Note that this display example is also an example in the case where the voltage applied to the liquid crystal cell 20 of the liquid crystal display 10 and the display color have the relationship of [Table 1] above, and thus the background color is “green”.

FIG. 15 shows a display state when not being used as a receiver. At this time, the time (AM in the figure) is displayed.
10:30) is displayed in "yellow". Next, the display when used as a receiver will be described.
Indicates the display status when the radio power is turned on.
At this time, instead of displaying the time, all the reception frequencies (AM · 1242 KHz in the figure) during the previous use are displayed in “blue”.

On the other hand, the radio broadcasting is tuned by either manual tuning by operating the AM / FM selector switch and the tuning dial or the tuning key of the key input section, or memory tuning by operating the memory tuning key. In manual tuning, the display of "AM" and "FM" is switched by switching AM / FM.
The displayed frequency changes continuously with tuning operation using the tuning dial or tuning key. In memory tuning, the reception frequency of each radio broadcast stored in the channel memory in advance is sequentially read by operating the memory tuning key, and the tuning status of the receiver and the display on the display are displayed for each radio broadcast. To be switched to. In addition,
The display color at the time of channel selection is "blue" as in FIG.

The reception frequency is registered in the channel memory by operating the memory registration key of the key input section to switch to the memory registration mode, and operating the AM / FM switch and the tuning dial or tuning key in that state. After setting the reception frequency to be stored in the channel memory and then operating the registration operation end key to store the set reception frequency in the channel memory, the set frequency is automatically stored when the set frequency is stored in the channel memory. The memory registration mode is released.

FIG. 17 shows the display state when the memory registration key is operated to switch to the memory registration mode. At this time, "MEMORY" indicating the registration operation state is displayed.
Is displayed in "purple" and the color of the received frequency "AM" or "FM" and the received frequency is also "purple"
become.

This display color is maintained until the AM / FM switch and the tuning dial or the tuning key are operated to set the reception frequency to be stored in the channel memory. FIG. 18 shows a display state when the reception frequency is set. In the figure, the reception frequency to be stored in the channel memory is FM.80.25M.
The state is set to Hz.

Further, FIG. 19 shows a display state when the reception frequency set by operating the registration operation end key is stored in the channel memory, and the set frequency is stored in the channel memory automatically. When the memory registration mode is released, the display of "MEMORY" indicating the registration operation state disappears, and the display color of the reception frequency becomes "blue", which is the same as when receiving a normal radio broadcast.

The display colors of the above display example are green, purple, yellow,
Although there are four colors of blue, the display color of the liquid crystal display body 10 of the color liquid crystal display device is as follows: Δn · d of the liquid crystal cell 20, the liquid crystal molecule orientation direction a of the liquid crystal cell 20, and the transmission axes of the polarizing plates 31 and 32. It can be arbitrarily selected by selecting the shift angle ψ between the liquid crystal cell 31a and 32a, and in that case, the display color of the portion corresponding to each segment electrode 24 of the liquid crystal cell 20 depends on the voltage applied to the liquid crystal cell 20. Change to multiple colors.

Further, in the above embodiment, the pair of polarizing plates 3
Although the transmission axes 31a and 32a of the polarizing plates 1 and 32 are substantially parallel to each other, the two polarizing plates 31 and 32 have the transmission axes 31a and 32a.
32a may be arranged substantially orthogonal to each other, and
Polarizing plate 3 for liquid crystal molecule alignment direction a of liquid crystal cell 20
The deviation angle ψ of the transmission axes 31a of the reference numerals 1 and 32 may be different for each polarizing plate. However, to obtain a sufficient coloring effect,
At least the transmission axis 31a of the upper polarizing plate 31 and the liquid crystal cell 20.
It is desirable that the deviation angle ψ with respect to the liquid crystal molecule alignment direction a is approximately 45 ° (for example, 45 ± 5 °).

Although a homogeneous alignment cell is used as the liquid crystal cell 20 in the above embodiment, the liquid crystal cell 20 may be one in which liquid crystal molecules are twist-aligned between both substrates.

FIG. 20 shows a liquid crystal molecule alignment direction of the liquid crystal cell 20 according to the second embodiment of the first invention and a pair of polarizing plates 31,
It is a top view which shows the transmission axis of 32. In this embodiment, as the liquid crystal cell 20, an STN type liquid crystal cell in which liquid crystal molecules are twist-aligned between the substrates 21 and 22 at a twist angle of 180 to 270 ° is used, and the liquid crystal display 1 shown in FIG.
0 is the STN type liquid crystal cell 20 and a pair of polarizing plates 31,
32 and a reflection plate 33.

In FIG. 20, 21a is a liquid crystal molecule alignment direction on the upper substrate 21 side of the liquid crystal cell 20, and 22a is a lower substrate 22.
The liquid crystal molecule alignment direction on the side is shown. Both boards 21,
The liquid crystal molecule alignment directions 21a and 22a on the 22 side are inclined in directions opposite to each other with respect to a reference line (horizontal line in the drawing) O by a predetermined angle θ, and the twist direction of liquid crystal molecules is indicated by an arrow T in the figure. As described above, from the lower substrate 22 side to the upper substrate 2
The twist orientation is toward the 1 side. In this embodiment, as the liquid crystal cell 20, the angles θ between the liquid crystal molecule alignment directions 21a and 22a on both substrates 21 and 22 and the reference line O are set to 30 °, and the liquid crystal molecules are twisted at a twist angle of 240 °. An oriented STN type liquid crystal cell is used.

In FIG. 20, 31a is the transmission axis of the upper polarizing plate 31, 32a is the transmission axis of the lower polarizing plate 32,
These polarizing plates 31 and 32 have their transmission axes 31 respectively.
a and 32a are arranged so as to be slanted by a predetermined angle with respect to the liquid crystal molecule alignment directions 21a and 22a on the upper and lower substrates 21 and 22 of the liquid crystal cell 20.

That is, in FIG. 20, φ1 is the inclination angle of the transmission axis 31a of the upper polarizing plate 31 with respect to the reference line O,
φ 2 is the transmission axis 32 of the lower polarizing plate 32 with respect to the reference line O
is the tilt angle of a, and the transmission axis 31a of the upper polarizing plate 31 is shifted counterclockwise (θ + φ1) ° with respect to the liquid crystal molecule alignment direction 21a on the upper substrate 21 side of the liquid crystal cell 20, and the lower polarizing plate 32
The transmission axis 32a of the liquid crystal cell 20 is counterclockwise in the drawing with respect to the liquid crystal molecule alignment direction 22a on the lower substrate 22 side of the liquid crystal cell 20 (θ-φ2).
Deviated. In this embodiment, φ1 = 100
°, φ2 = 75 °, θ + φ1 = 130 °, θ-φ2
= 45 °.

Coloring of light by the liquid crystal display 10 using the STN type liquid crystal cell 20 will be described below.
The N-type liquid crystal cell 20 has a polarization effect of elliptically polarizing the incident linearly polarized light due to the birefringence effect in the liquid crystal layer in which the liquid crystal molecules are twisted, and the transmission axis 31 a of the upper polarizing plate 31 is the liquid crystal cell 20. Since it is obliquely displaced from the liquid crystal molecule alignment direction 21a on the upper substrate 21 side,
In the state where no voltage is applied between the electrodes 23 and 24 of the liquid crystal cell 20 (the state in which the liquid crystal molecules are twisted),
The light linearly polarized by the upper polarization plate 31 and incident on the liquid crystal cell 20 and the transmission axis 31 a of the upper polarization plate 31 and the liquid crystal cell 20.
The light is polarized into elliptically polarized light by being subjected to a polarization action according to the deviation angle from the liquid crystal molecule alignment direction 21a on the upper substrate 21 side and the value of Δn · d of the liquid crystal cell 20.

Therefore, at this time, of the elliptically polarized light that is emitted from the liquid crystal cell 20 and is incident on the lower polarizing plate 32, only the wavelength light of the polarization component that is transmitted through the lower polarizing plate 32 is transmitted through this lower polarizing plate 32. Therefore, the light (linearly polarized light) that has passed through the lower polarizing plate 32 becomes colored light.

On the other hand, when a voltage is applied between the electrodes 23 and 24 of the liquid crystal cell 20, as the liquid crystal molecules of the liquid crystal cell 20 rise and align with respect to the surfaces of the substrates 21 and 22, the birefringence potential of the liquid crystal is increased. Since the phase difference Δn becomes small, the liquid crystal cell 20
Since the value of Δn · d becomes smaller, the polarization effect in the liquid crystal cell 20 becomes smaller.

When the polarization action of the liquid crystal cell 20 changes, the polarization state of the elliptically polarized light that exits the liquid crystal cell 20 and enters the lower polarizing plate 32 changes, so that the color of the colored light passing through the lower polarizing plate 32 changes. Changes.

When the liquid crystal molecules of the liquid crystal cell 20 rise vertically, the polarization action in the liquid crystal cell 20 becomes “0”, and the light linearly polarized by the upper polarizing plate 31 and incident on the liquid crystal cell 20. Transmits through the liquid crystal cell 20 in its polarization state (linearly polarized light), but in this embodiment, the transmission axis 32a of the lower polarization plate 32 and the transmission axis 31a of the upper polarization plate 31 are transmitted.
Since and are deviated by φ1 −φ2 = 85 °,
Only light of the wavelength of the polarization component that passes through the lower polarizing plate 32 passes through the lower polarizing plate 32, and the light that has passed through the lower polarizing plate 32 becomes colored light.

The colored light that has passed through the lower polarizing plate 32 is reflected by the reflection plate 33 and is emitted to the upper surface side of the liquid crystal display 10 through a route opposite to the above-described optical route, and this colored light causes a display pattern to be formed. Is displayed.

Also in this case, the colored light reflected by the reflection plate 33 is the wavelength light of the polarization component that has passed through the lower polarization plate 32 of the light that has become elliptically polarized light by the polarization action of the liquid crystal cell 20 described above. Therefore, most of the colored light reflected by the reflection plate 33 is transmitted through the liquid crystal cell 20 without being polarized by the liquid crystal cell 20, but the light having a very small wavelength component at the end of the wavelength range is the liquid crystal. Since the colored light that is polarized in the process of passing through the cell 20 is absorbed by the upper polarizing plate 31, the colored light that passes through the upper polarizing plate 31 and is emitted has a better color purity than the colored light reflected by the reflecting plate 33. It becomes the light.

As described above, the color liquid crystal display device of the above embodiment also colors the transmitted light without using a color filter due to the polarization effect of the liquid crystal cell 20, and therefore the amount of the colored light is different from that of the display device. Since the amount of light in the wavelength band that becomes the colored light of the incident light is almost the same, the light transmittance can be increased to sufficiently increase the brightness of the display, and the liquid crystal cell 20 By applying a drive voltage for selectively displaying a plurality of colors between the common electrode and each segment electrode, the display color of the portion corresponding to the same segment electrode can be changed to a plurality of colors.

The display color of the liquid crystal display body 10 in this color liquid crystal display device is as follows: Δn · d of the liquid crystal cell 20, the liquid crystal molecule twist angle, and the upper and lower substrates 21, 2 of the liquid crystal cell 20.
It is determined by the shift angles of the transmission axes 31a and 32a of the pair of polarizing plates 31 and 32 with respect to the liquid crystal molecule alignment directions 21a and 22a on the second side.

As an example, Δn of the liquid crystal cell 20 is
・ D is 1.1238 μm, and twist angle of liquid crystal molecules is 24
0 °, the shift angle of the transmission axis 31a of the upper polarization plate 31 with respect to the liquid crystal molecule alignment direction 21a on the upper substrate 21 side of the liquid crystal cell 20 is 130 ° counterclockwise in FIG. 20, and the liquid crystal molecule on the lower substrate 22 side of the liquid crystal cell 20 is Lower polarizing plate 3 with respect to orientation direction 22a
The shift angle of the transmission axis 32a of 2 is 4 in the counterclockwise direction in FIG.
When the angle is set to 5 °, the display color is “red” when the liquid crystal molecules of the liquid crystal cell 20 are in the initial twist alignment state, and the display color is “black” when the liquid crystal molecules are almost vertically risen and aligned. Further, in the process in which the liquid crystal molecules rise from the initial twist alignment state to the rise alignment, display colors of “green” and “blue” having high light intensity and high color purity are obtained.

The following [Table 2] shows the relationship between the voltage applied to the liquid crystal cell 20 of the liquid crystal display 10 and the display color. In addition, in this [Table 2], the value of the applied voltage is an effective voltage value applied between the electrodes 23 and 34 of the liquid crystal cell 20.

[0113]

[Table 2]

The display colors of [Table 2] are red, green,
Although there are four colors of blue and black, the display colors of the liquid crystal display 10 are Δn · d and the liquid crystal molecule twist angle of the liquid crystal cell 20, and the alignment directions of the liquid crystal molecules on the upper and lower substrates 21 and 22 of the liquid crystal cell 20. 21a, 22a pair of polarizing plates 31, 3
It can be arbitrarily selected by selecting the shift angles of the two transmission axes 31a and 32a, and in that case also, the liquid crystal cell 20
The display color of the portion corresponding to each segment electrode 24 changes to a plurality of colors according to the voltage applied to the liquid crystal cell 20.

In the second embodiment, the liquid crystal cell 2
The STN type was used for 0, but this liquid crystal cell 20
A TN cell in which the twist angle of liquid crystal molecules is approximately 90 ° may be used.

Furthermore, the first invention is not limited to the reflection type in which the reflection plate is arranged on the back surface side, but can be applied to a transmission type color liquid crystal display device, and the liquid crystal cell 20 is also used. The drive is not limited to time-division drive, and may be static drive.

[Embodiment of the Second Invention] Next, the first embodiment of the second invention will be described with reference to FIGS. 21 and 22. FIG. 21 is a configuration diagram of a color liquid crystal display device. The color liquid crystal display device includes a liquid crystal display body 10 and a display drive circuit 40 thereof. Note that in FIG.
Components corresponding to those shown in are denoted by the same reference numerals, and redundant description will be omitted.

The liquid crystal display 10 comprises one segment display type liquid crystal cell 20, one polarizing plate 31 and one reflecting plate 33. The polarizing plate 31 is the liquid crystal cell 20.
Is arranged on the front surface side (upper surface in the drawing) side, and the reflection plate 33 is arranged on the back surface side (lower surface in the drawing) side of the liquid crystal cell 20.

FIG. 22 is a plan view showing the alignment direction of the liquid crystal molecules of the liquid crystal cell 20 and the transmission axis of the polarizing plate 31. In the figure, 21a is the alignment direction of the liquid crystal molecules on the upper substrate 21 side of the liquid crystal cell 20, and 22a. Indicates the alignment direction of liquid crystal molecules on the lower substrate 22 side.

In this embodiment, a homogeneous alignment cell is used for the liquid crystal cell 20, and the polarizing plate 31 has its transmission axis 31a in a predetermined direction with respect to the liquid crystal molecule alignment direction (homogeneous alignment direction) a of the liquid crystal cell 20. They are arranged diagonally intersecting at a deviation angle ψ. In this embodiment, the liquid crystal molecule alignment direction a of the liquid crystal cell 20 and the transmission axis 31 of the polarizing plate 31 are arranged.
The deviation angle ψ with a is 45 °.

This color liquid crystal display device is of a reflection type in which light incident from the front surface side (natural light or light from an illumination light source) is reflected by the reflection plate 33 on the rear surface side and displayed. Incident light is generated by the polarizing plate 31 and the liquid crystal cell 20.
The liquid crystal cell 20 is reflected by the reflection plate 33 through
And goes out through the polarizing plate 31.

On the other hand, the display drive circuit 40 is similar to the display drive circuit 40 of the color liquid crystal display device shown in FIG.
Each common electrode 23 and each segment electrode 2 of the liquid crystal cell 20
A driving voltage for selectively displaying the plurality of colors is applied between the driving voltage and the driving voltage.

In this color liquid crystal display device, the linearly polarized light incident through the polarizing plate 31 has a liquid crystal molecule alignment direction a at a predetermined angle (ψ in this embodiment) with respect to the transmission axis 31a of the polarizing plate 31. (= 45 °) The polarization state can be changed by the polarization action in the process of passing through the liquid crystal cell 20 which is obliquely displaced, and further changed in the process of passing through the liquid crystal cell 20 after being reflected by the reflection plate 33.

Therefore, the retardation plate 30 and the liquid crystal cell 2 are
The light that passes through 0 and enters the polarizing plate 31 again is the liquid crystal cell 2
It is an elliptically polarized light that has been subjected to a polarization effect of 2 degrees by 0, and therefore, only the light of the wavelength of the polarization component that passes through the polarizing plate 31 out of this light passes through the polarizing plate 31 and is emitted, and the emitted light is the colored light. become.

Further, since the liquid crystal cell 20 exhibits a different polarization action depending on the alignment state of the liquid crystal molecules, the liquid crystal cell 2
The light that has been polarized by two degrees due to 0 becomes light having a different polarization state depending on the liquid crystal molecule alignment state of the liquid crystal cell 20 and enters the polarizing plate 31, so that by changing the liquid crystal molecule alignment state of the liquid crystal cell 20. The color of the colored light that passes through the polarizing plate 31 and is emitted can be changed.

Thus, the color liquid crystal display device described above
The transmitted light is colored without using a color filter. Therefore, the amount of the colored light is almost the same as the amount of the light in the wavelength band that becomes the colored light among the light incident on the display device. However, it is possible to increase the light transmittance to sufficiently increase the display brightness, and to provide a plurality of colors between the common electrode 23 of the liquid crystal cell 20 and each segment electrode 24. By applying a drive voltage for selectively displaying the same segment electrode 24
The display color of the portion corresponding to can be changed to a plurality of colors.

The display color of the liquid crystal display 10 in this color liquid crystal display device depends on Δn · d of the liquid crystal cell 20 and the deviation angle ψ of the transmission axis 31a of the polarizing plate 31 with respect to the liquid crystal molecule alignment direction a of the liquid crystal cell 20. Decided.

As an example, Δn of the liquid crystal cell 20 is
・ D is 1.1 μm, and the deviation angle ψ between the liquid crystal molecule alignment direction a of the liquid crystal cell 20 and the transmission axis 31a of the polarizing plate 31 is 45 °.
When, the display color when the liquid crystal molecules of the liquid crystal cell 20 are in the initial homogeneous alignment state is “pale green”, and the light intensity is increased in the process of rising alignment from the initial twist alignment state. The display colors are “purple”, “yellow”, and “red” with high color purity and high color purity.

The following [Table 3] shows the relationship between the voltage applied to the liquid crystal cell 20 of the liquid crystal display 10 and the display color. In addition, in this [Table 3], the value of the applied voltage is an effective voltage value applied between the electrodes 23 and 34 of the liquid crystal cell 20.

[0130]

[Table 3]

Although not shown in [Table 3], the display color is "white" (no color) when a voltage is applied to the liquid crystal cell 20 so that the liquid crystal molecules rise and align almost vertically. The liquid crystal display body 10 of the color liquid crystal display device is configured such that the display drive circuit 40 causes the common electrodes 23 of the liquid crystal cell 20 to operate.
Since driving is performed by applying a driving voltage for selectively displaying a plurality of colors between each segment electrode 24 and each segment electrode 24, this color liquid crystal display device displays the display color of the portion corresponding to the same segment electrode 24. It can be changed to multiple colors.

The display color in [Table 3] above is light green,
Although there are four colors of purple, yellow, and blue, the display colors of the liquid crystal display body 10 are Δn · d of the liquid crystal cell 20 and deviation of the transmission axis 31a of the polarizing plate 31 with respect to the liquid crystal molecule alignment direction a of the liquid crystal cell 20. It can be chosen arbitrarily by choosing the angle ψ and
Also in this case, the display color of the portion corresponding to each segment electrode 24 of the liquid crystal cell 20 changes to a plurality of colors according to the voltage applied to the liquid crystal cell 20. However, in this case as well, in order to obtain a sufficient coloring effect, the shift angle ψ between the transmission axis 31a of the polarizing plate 31 and the liquid crystal molecule alignment direction a of the liquid crystal cell 20 is approximately 45.
It is desirable to set the angle (for example, 45 ± 5 °).

Further, in the above embodiment, a homogeneous alignment cell is used as the liquid crystal cell 20, but the liquid crystal cell 20 may be one in which liquid crystal molecules are twist-aligned between both substrates.

FIG. 23 shows a liquid crystal molecule alignment direction of the liquid crystal cell 20 according to the second embodiment of the second invention and a pair of polarizing plates 31,
It is a top view which shows the transmission axis of 32. In this embodiment, as the liquid crystal cell 20, an STN type liquid crystal cell in which liquid crystal molecules are twist-aligned between the substrates 21 and 22 at a twist angle of 180 to 270 ° is used, and the liquid crystal display 1 shown in FIG.
0 is composed of the STN type liquid crystal cell 20, one polarizing plate 31 and a reflecting plate 33.

In FIG. 23, 21a is a liquid crystal molecule alignment direction on the upper substrate 21 side of the liquid crystal cell 20, and 22a is a lower substrate 22.
The liquid crystal molecule alignment direction on the side is shown. Both boards 21,
The liquid crystal molecule alignment directions 21a and 22a on the 22 side are inclined in directions opposite to each other with respect to a reference line (horizontal line in the drawing) O by a predetermined angle θ, and the twist direction of liquid crystal molecules is indicated by an arrow T in the figure. As described above, from the lower substrate 22 side to the upper substrate 2
The twist orientation is toward the 1 side. In this embodiment, as the liquid crystal cell 20, the angles θ between the liquid crystal molecule alignment directions 21a and 22a on both substrates 21 and 22 and the reference line O are set to 30 °, and the liquid crystal molecules are twisted at a twist angle of 240 °. An oriented STN type liquid crystal cell is used.

Further, in FIG. 23, reference numeral 31a denotes the polarizing plate 3
The polarizing plate 31 is arranged such that its transmission axis 31a is slanted by a predetermined angle with respect to the liquid crystal molecule alignment direction 21a on the upper substrate 21 side of the liquid crystal cell 20.

That is, in FIG. 23, φ is the inclination angle of the transmission axis 31a of the polarizing plate 31 with respect to the reference line O, and the transmission axis 31a of the polarizing plate 31 is a liquid crystal molecule on the upper substrate 21 side of the liquid crystal cell 20. It is shifted (θ + φ) ° counterclockwise in the figure with respect to the orientation direction 21a. In this embodiment, φ = 120 ° and θ + φ = 150 °.

This color liquid crystal display device also has a liquid crystal cell 20.
The liquid crystal display body including the polarizing plate 31 and the reflection plate 33 is caused to perform colored display by the polarization action of the liquid crystal cell 20, and the display color of the liquid crystal display body 10 is Δn of the liquid crystal cell 20. D and the liquid crystal molecule twist angle, and the deviation angle θφ + θ between the liquid crystal molecule alignment direction 21a on the upper substrate 21 side of the liquid crystal cell 20 and the transmission axis 31a of the polarizing plate 31.

As an example, Δn of the liquid crystal cell 20 is
・ D is 0.1238μm, liquid crystal molecule twist angle is 240
° Deviation angle θφ + between liquid crystal molecule alignment direction 21a on the upper substrate 21 side of liquid crystal cell 20 and transmission axis 31a of polarizing plate 31
When θ is set to 45 °, the display color when the liquid crystal molecules of the liquid crystal cell 20 are in the initial twist alignment state is “pale green”.
In the process in which the liquid crystal molecules rise from the initial twist alignment state to the rise alignment, the display colors are “dark green”, “purple”, and “orange” with high light intensity and high color purity.

The following [Table 4] shows the relationship between the voltage applied to the liquid crystal cell 20 of the liquid crystal display 10 and the display color. In addition, in this [Table 4], the value of the applied voltage is an effective voltage value applied between the electrodes 23 and 34 of the liquid crystal cell 20.

[0141]

[Table 4]

Although not shown in [Table 4],
When the liquid crystal molecules of the liquid crystal cell 20 rise vertically, the polarization action in the liquid crystal cell 20 becomes “0”, and the light linearly polarized by the polarizing plate 31 and incident on the liquid crystal cell 20 has its polarization state (linear polarization). Since it passes through the liquid crystal cell 20 as it is, the display color becomes “white” (no color).

The liquid crystal display body 10 of the color liquid crystal display device is driven by the display drive circuit 40 to selectively display a plurality of colors between each common electrode 23 and each segment electrode 24 of the liquid crystal cell 20. Since the color liquid crystal display device is driven by applying a voltage, the display color of the portion corresponding to the same segment electrode 24 can be changed to a plurality of colors.

Although the liquid crystal cell 20 of the STN type is used in the above embodiment, this liquid crystal cell 20
May be a TN type in which the twist angle of liquid crystal molecules is approximately 90 °.

[0145]

In the color liquid crystal display device of the first invention, a pair of polarizing plates are arranged with a segment display type liquid crystal cell sandwiched therebetween, and the alignment directions of liquid crystal molecules on both substrate sides of the liquid crystal cell are respectively set. A liquid crystal that is slanted by a predetermined angle with respect to the transmission axes of the pair of polarizing plates, and the display color of the portion corresponding to each segment electrode of the liquid crystal cell changes into a plurality of colors according to the voltage applied to the liquid crystal cell. Since the display body and the display drive means for applying a drive voltage for selectively displaying the plurality of colors are provided between the common electrode of the liquid crystal cell and each segment electrode, a color filter is not used. The transmitted light can be colored to increase the light transmittance, and the brightness of the display can be made sufficiently high.Although the segment display type liquid crystal cell is used, the same segment The display color of the portion corresponding can be changed in plural colors.

In the color liquid crystal display device of the second invention, a polarizing plate is arranged on the front surface side of the segment display type liquid crystal cell, a reflector is arranged on the rear surface side of the liquid crystal cell, and the liquid crystal cell of the liquid crystal cell is arranged. The orientation directions of the liquid crystal molecules on both the substrate sides are each shifted obliquely by a predetermined angle with respect to the transmission axis of the polarizing plate, and the display color of the portion corresponding to each segment electrode of the liquid crystal cell is set to the voltage applied to the liquid crystal cell. A liquid crystal display body that changes into a plurality of colors in accordance with the display means, and a display drive unit that applies a drive voltage for selectively displaying the plurality of colors between the common electrode of the liquid crystal cell and each segment electrode. Therefore, it is possible to color the transmitted light without using a color filter to increase the light transmittance and sufficiently increase the display brightness, and to use a segment display type liquid crystal cell. There will, it is possible to change the display color of the portion corresponding to the same segment electrode a plurality of colors.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a color liquid crystal display device according to a first embodiment of the first invention.

FIG. 2 is a plan view showing a liquid crystal molecule alignment direction of a liquid crystal cell, a slow axis of a retardation plate, and a transmission axis of a polarizing plate according to the example.

FIG. 3 is a shape diagram of a segment electrode formed on one substrate of a liquid crystal cell showing an example in which a color liquid crystal display device is applied to a calculator.

FIG. 4 is a display state diagram when the display data showing a display example of a calculator is a positive (+) numerical value and there is no error.

FIG. 5 is a display state diagram when the display data is a negative (−) numerical value.

FIG. 6 is a display state diagram when there is an error.

FIG. 7 is a block diagram showing a circuit configuration of a calculator.

FIG. 8 is a shape diagram of a segment electrode formed on one substrate of a liquid crystal cell showing an example in which a color liquid crystal display device is applied to an electronic timepiece having an alarm function.

FIG. 9 is a normal display state diagram showing a display example of a clock.

FIG. 10 is a display state diagram when an alarm is also set.

FIG. 11 is a display state diagram when the remaining time up to the alarm set time is 30 minutes or less.

FIG. 12 is a display state diagram when the remaining time up to the alarm setting time is 10 minutes or less.

FIG. 13 is a display state diagram when the alarm set time has come.

FIG. 14 is a shape diagram of segment electrodes formed on one substrate of a liquid crystal cell showing an example in which a color liquid crystal display device is applied to a radio receiver having a clock function and a channel memory function.

FIG. 15 is a display state diagram showing a display example of a radio receiver when not being used as a receiver.

FIG. 16 is a display state diagram when the radio power is turned on.

FIG. 17 is a display state diagram when switching to the memory registration mode in the same manner.

FIG. 18 is a display state diagram when the reception frequency to be stored in the channel memory is likewise set.

FIG. 19 is a display state diagram when the same set reception frequency is stored in a channel memory.

FIG. 20 is a plan view showing an alignment direction of liquid crystal molecules of a liquid crystal cell, a slow axis of a retardation plate, and a transmission axis of a polarizing plate according to a second embodiment of the first invention.

FIG. 21 is a configuration diagram of a color liquid crystal display device according to a first embodiment of the second invention.

FIG. 22 is a plan view showing the alignment direction of liquid crystal molecules of the liquid crystal cell, the slow axis of the retardation plate, and the transmission axis of the polarizing plate according to the example.

FIG. 23 is a plan view showing an alignment direction of liquid crystal molecules of a liquid crystal cell, a slow axis of a retardation plate, and a transmission axis of a polarizing plate according to a second embodiment of the second invention.

[Explanation of symbols]

10 ... Liquid crystal display body 20 ... Liquid crystal cell 21, 22 ... Transparent substrate a ... Liquid crystal molecule alignment direction of homogeneous alignment liquid crystal cell 21a ... Liquid crystal molecule alignment direction on upper substrate side of STN type liquid crystal cell 22a ... Lower substrate of STN type liquid crystal cell Alignment direction of liquid crystal molecules on side 23 ... Common electrode 24 ... Segment electrodes 25, 26 ... Alignment film 28 ... Liquid crystal 30a ... Slow axis 31, 32 ... Polarizing plate 31a, 32a ... Transmission axis 33 ... Reflector 40 ... Display drive circuit

Claims (6)

[Claims] 1. A pair of polarizing plates are arranged with a liquid crystal cell filled with liquid crystal interposed between a transparent substrate having a plurality of segment electrodes and a transparent substrate having a common electrode facing the segment electrodes. The alignment direction of the liquid crystal molecules on both substrate sides of the liquid crystal cell is shifted obliquely by a predetermined angle with respect to the transmission axes of the pair of polarizing plates, and the display color of the portion corresponding to each segment electrode of the liquid crystal cell is A liquid crystal display that changes to a plurality of colors according to the voltage applied to the liquid crystal cell, and a display that applies a driving voltage for selectively displaying the plurality of colors between the common electrode and each segment electrode of the liquid crystal cell A color liquid crystal display device comprising a driving means. 2. The color liquid crystal display device according to claim 1, wherein the liquid crystal cell is one in which liquid crystal molecules are homogeneously aligned. 3. A liquid crystal cell in which liquid crystal molecules are twist-aligned between both substrates.
The color liquid crystal display device described in 1. 4. A polarizing plate is disposed on the surface side of a liquid crystal cell in which liquid crystal is sealed between a transparent substrate having a plurality of segment electrodes and a transparent substrate having a common electrode facing the segment electrodes. A reflective plate is arranged on the back surface side of the cell, and the alignment directions of the liquid crystal molecules on both substrate sides of the liquid crystal cell are each shifted obliquely by a predetermined angle with respect to the transmission axis of the polarizing plate. And a liquid crystal display in which the display color of the portion corresponding to is changed to a plurality of colors according to the voltage applied to the liquid crystal cell, and the plurality of colors are selectively provided between the common electrode and each segment electrode of the liquid crystal cell. And a display driving means for applying a driving voltage for displaying the color liquid crystal display device. 5. The color liquid crystal display device according to claim 4, wherein the liquid crystal cell is one in which liquid crystal molecules are homogeneously aligned. 6. A liquid crystal cell in which liquid crystal molecules are twist-aligned between both substrates.
The color liquid crystal display device described in 1.