JP4861657B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device.

  In recent years, liquid crystal display devices have been applied to various fields and are used in electronic devices such as notebook computers, monitors, car navigation systems, scientific calculators, small and medium-sized TVs, large-sized TVs, mobile phones, and electronic notebooks.

  Among these electronic devices, electronic notebooks, personal digital assistants (PDAs), mobile phones, tablet personal computers (PCs), notebook PCs, and the like are frequently used by being carried around because of their small and thin features. In addition, liquid crystal display devices used for POP (point of purchase) applications, ATM (automated teller machine) applications, and ticket vending machine applications are often used in public places.

  In these applications, it may be difficult for others to identify the display contents depending on the usage situation. For example, it is a case where private contents are displayed on a mobile phone, PDA, or tablet PC in a public place. In such a case, it is desirable that the viewing angle is narrow. However, since there are opportunities for a plurality of people to observe the display image, it is desired to have a function of controlling the viewing angle. The problem of viewing angle characteristics is a problem common to mobile devices and public information terminal devices.

  In recent years, a detachable louver sheet (for example, a 3M light control film) has been used as a means for controlling the viewing angle of a liquid crystal display device or a cathode ray tube (CRT) (for example, see Patent Document 1). In addition, in a liquid crystal display device using a polarizing plate, a system in which a polarizing plate on the viewer side is not provided and the display can be identified only when polarizing glasses are applied is also applied.

The conventional louver sheet is provided with a light shielding layer of about several millimeters in the normal direction of the sheet in order to make the viewing angle sufficiently narrow. For this reason, the method using the louver sheet has a problem of low light transmittance. The louver sheet manufacturing process is complicated and the manufacturing cost is high. There is also a problem that it takes time to attach and detach the louver sheet. In addition, the method using polarized glasses has a problem that a display image cannot be shown to an unspecified person.
JP 2003-58066 A

In order to solve the problem of the viewing angle characteristic, a liquid crystal display device has been developed in which a viewing angle control liquid crystal element for controlling a viewing angle is provided in the liquid crystal display device to control the viewing angle. However, since the viewing angle control liquid crystal element always performs the viewing angle control by applying a high voltage or a high current, power consumption for performing the viewing angle control increases.
The present invention has been made in view of the above points, and an object of the present invention is to provide a liquid crystal display device that is excellent in viewing angle control and can reduce power consumption.

In order to solve the above-described problem, a liquid crystal display device according to an aspect of the present invention includes:
A liquid crystal display panel, comprising: an array substrate; a counter substrate disposed opposite to the array substrate with a predetermined gap; and a first liquid crystal layer sandwiched between the array substrate and the counter substrate;
A first substrate having a first alignment layer that overlaps the first electrode and the first electrode, and a first substrate that is opposed to the first substrate with a predetermined gap, and that overlaps the second electrode and the second electrode. a second substrate having a second alignment film facing the first alignment layer with which said sandwiched between the first substrate and the second substrate, and elevated potential after the potential difference between two substrates with the phase state of the light is different for transmission between two substrates with the potential difference after falling and, after the potential difference is increased to a first potential difference, said first potential difference, the lowered from the first potential difference between 2 potential, the second liquid crystal layer for maintaining the phase state at the first potential difference, wherein the provided et al are opposite substrate facing the liquid crystal display panel, passes between the two substrates The phase state of light is controlled based on the potential difference. In is characterized in that it comprises and phase control liquid crystal element for controlling a viewing angle, a.

In addition, a liquid crystal display device according to another aspect of the present invention includes:
A liquid crystal display panel, comprising: an array substrate; a counter substrate disposed opposite to the array substrate with a predetermined gap; and a first liquid crystal layer sandwiched between the array substrate and the counter substrate;
A first substrate having a first electrode and a first alignment film overlying the first electrode, a first electrode, a second electrode, and the second electrode, disposed opposite to each other with a predetermined gap therebetween And a second substrate having a second alignment film opposite to the first alignment film, and sandwiched between the first substrate and the second substrate, and the potential difference between the two substrates is increased The phase difference of the light transmitted between the two substrates is different between the potential difference after the decrease and the potential difference after the decrease, and after the potential difference has increased to the first potential difference, the first potential difference and the first potential difference have decreased. between the second potential difference, the second liquid crystal layer for maintaining the phase state at the first potential difference, wherein the provided et al are opposite substrate facing the liquid crystal display panel, between the two substrates Control the phase state of transmitted light based on the potential difference And phase control liquid crystal element for controlling the viewing angle by,
A third substrate having a third electrode and a third alignment film overlapping with the third electrode, a third electrode being opposed to the third substrate with a predetermined gap, and a fourth electrode and the fourth electrode And a fourth substrate having a fourth alignment film opposite to the third alignment film and sandwiched between the third substrate and the fourth substrate, and the potential difference between the two substrates is increased And the potential difference after the decrease, the diffusion state of the light transmitted between the two substrates is different, the potential difference rises to the third potential difference, then drops from the third potential difference, and the first A third liquid crystal layer that maintains the diffusion state at the time of the fourth potential difference between the fourth potential difference in a diffusion state different from the diffusion state at the time of three potential differences and the fifth potential difference further lowered from the fourth potential difference. And including an LCD panel It is characterized in that and a luminance viewing angle control liquid crystal element provided in Lee substrate and a counter.

  According to the present invention, it is possible to provide a liquid crystal display device that is excellent in viewing angle control and can reduce power consumption.

Hereinafter, a liquid crystal display device according to a first embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the liquid crystal display device includes a phase control liquid crystal element 1, a liquid crystal display panel 3, a first polarizing plate 41, a second polarizing plate 42, a backlight unit 51, a luminance viewing angle control liquid crystal element 4, and a driving unit. 5 is provided.

  The phase control liquid crystal element 1 includes a first substrate 11, a second substrate 12 that is opposed to the first substrate with a predetermined gap, and a first liquid crystal layer 13. The first substrate 11 is a transparent insulating substrate, for example, a first sheet 14a made of a polyester film or glass, and a transparent conductive material such as ITO (indium tin oxide) disposed on the first sheet. It has the 1st electrode 16a formed with the material, and the 1st alignment film 17a arrange | positioned on this 1st electrode. The second substrate 12 is, as a transparent insulating substrate, a second sheet 14b made of, for example, a polyester film or glass, and a second sheet formed on the second sheet and formed of a transparent conductive material such as ITO. It has an electrode 16b and a second alignment film 17b disposed on the second electrode. The first alignment film 17a and the second alignment film 17b are rubbed so that the pretilt angle is 88 °.

  The first substrate 11 and the second substrate 12 are arranged to face each other so that the first alignment film 17a and the second alignment film 17b face each other, and are held by a plurality of first spacers 18 with a predetermined gap. The first spacer 18 is made of an insulating material. The first electrode 16a and the second electrode 16b are maintained in an insulated state. The first substrate 11 and the second substrate 12 are regions where the first electrode 16a and the second electrode 16b are opposed to each other, and the phase control capable of controlling the phase state of the light transmitted between the first substrate and the second substrate. It has area | region R1. The first substrate 11 and the second substrate 12 are joined to each other by a sealing material 19 disposed at the peripheral portions of the first electrode 16a and the second electrode 16b. The first liquid crystal layer 13 is sandwiched between the first substrate 11, the second substrate 12, and the sealing material 19.

  The layer thickness of the first liquid crystal layer 13 is 5.0 μm. A predetermined chiral material is added to the liquid crystal material constituting the first liquid crystal layer 13 so as to obtain the following characteristics. The difference in refractive index anisotropy (Δn) of the liquid crystal material is 0.042 for a wavelength of 590 nm. The twist angle of the liquid crystal molecules is 450 ° and the twist pitch is 3.57 μm. The twist of the liquid crystal molecules is counterclockwise.

  The first liquid crystal layer 13 described above has a function of controlling the phase state of light transmitted between the first substrate 11 and the second substrate 12. More specifically, the first liquid crystal layer 13 controls the viewing angle by controlling the orientation of the liquid crystal molecules. When controlling the orientation of the liquid crystal molecules in the first liquid crystal layer 13, a voltage is applied to the phase control liquid crystal element 1 to control the potential difference between the first electrode 16a and the second electrode 16b. The display mode of the phase control liquid crystal element 1 is an n-type phase change mode. The n-type phase change mode will be described later.

Next, a method for manufacturing the phase control liquid crystal element 1 will be described.
The first electrode 16a is formed on the prepared first sheet 14a, and the first alignment film 17a is applied on the first sheet and the first electrode. Thereafter, the first alignment film 17a is rubbed as an alignment process to form the first substrate 11. On the other hand, in the second substrate 12, the second electrode 16b is formed on the prepared second sheet 14b, and the second alignment film 17b is applied on the second sheet and the second electrode. Thereafter, the second alignment film 17b is rubbed as an alignment treatment to form the second substrate 12.

  Next, after spraying spacers on the first substrate 11 or the second substrate 12, for example, a thermosetting sealing material 19 is applied to the peripheral portion of the first substrate or the second substrate. Subsequently, the first substrate 11 and the second substrate 12 are arranged to face each other and baked. Thereby, the 1st board | substrate 11 and the 2nd board | substrate 12 are joined. Thereafter, a liquid crystal is filled between the first substrate 11 and the second substrate 12. When filling, for example, using a method such as a vacuum injection method, liquid crystal is injected from a liquid crystal injection port provided in a part of the sealing material 19 and filled. The liquid crystal injection port is sealed with a sealing material.

Next, the position information detection function of the phase control liquid crystal element 1 will be described.
As shown in FIGS. 1 and 2, the phase control liquid crystal element 1 also functions as a resistance detection type touch panel. The phase control liquid crystal element 1 includes an input region R3 where the first electrode 16a and the second electrode 16b overlap each other, and the position information detection unit 2.

  The position information detection unit 2 includes first resistance detection electrodes 15a and 15b and second resistance detection electrodes 15c and 15d, and has a function of detecting position information of a pressed portion of the input region R3. The first resistance detection electrodes 15a and 15b are respectively connected to a rectangular first electrode (resistance layer) 16a on the first substrate 11 and provided on a pair of opposite sides of the first electrode. The second resistance detection electrodes 15c and 15d are respectively positioned orthogonal to the first electrode (resistance layer) 16a on the second substrate 12 and are connected to the rectangular second electrode 16b and are connected to the second electrode 16b. It is provided on a pair of opposing sides of the electrode. Here, the second substrate 12 includes an input surface S overlapping the input region R3. As will be described later, the second polarizing plate 42 is disposed on the input surface S of the second substrate 12.

  When the outer surface of the second polarizing plate 42 (phase control liquid crystal element 1) is pressed, the first electrode 16a and the second electrode 16b come into contact with each other, so that the position information detection unit 2 has a resistance between the electrodes (first Between the resistance detection electrode 15a and the second resistance detection electrode 15c, between the first resistance detection electrode 15a and the second resistance detection electrode 15d, between the first resistance detection electrode 15b and the second resistance detection electrode 15c, and the first resistance detection electrode 15b. In addition, the position information of the pressed portion can be detected by measuring four types between the second resistance detection electrode 15d and the second resistance detection electrode 15d. The first resistance detection electrodes 15a and 15b and the second resistance detection electrodes 15c and 15d are formed by depositing a low resistance metal such as Al or Mo by vapor deposition or sputtering and then patterning it. Thereby, the phase control liquid crystal element 1 is completed.

  The liquid crystal display panel 3 is configured as a TN (twisted nematic) mode liquid crystal display panel. The liquid crystal display panel 3 includes an array substrate 21 as a third substrate, a counter substrate 22 as a fourth substrate, and a second liquid crystal layer 23. The array substrate 21 includes a glass substrate 24 as a transparent insulating substrate, a plurality of pixel electrodes 25 formed on the glass substrate, an alignment film 26 formed on the glass substrate including the pixel electrodes 25, have. The array substrate 21 has various wirings (not shown) formed on the glass substrate 24, thin film transistors (hereinafter referred to as TFTs) as switching elements, and the like. The counter substrate 22 includes a glass substrate 27 as a transparent insulating substrate, a common electrode 28 formed on the glass substrate, and an alignment film 29 formed on the common electrode and the glass substrate. In this embodiment, the first sheet 14a and the glass substrate 27 are integrally formed. For this reason, the first substrate 11 of the phase control liquid crystal element 1 and the counter substrate 22 of the liquid crystal display panel 3 have a transparent common substrate 71, and are configured by the same substrate. The pixel electrode 25 and the common electrode 28 are formed of a transparent conductive material such as ITO. The alignment film 26 and the alignment film 29 are rubbed so that the pretilt angle is 5 °.

  The array substrate 21 and the counter substrate 22 are arranged to face each other while holding a predetermined gap by a plurality of second spacers 30. The array substrate 21 and the counter substrate 22 have a display region R2 for displaying an image while the pixel electrode 25 and the common electrode 28 face each other. In this embodiment, the display region R2 overlaps with the phase control region R1 described above. The array substrate 21 and the counter substrate 22 are joined to each other by a sealing material 31 disposed on the outer peripheral portion of both substrates outside the display region R2. The second liquid crystal layer 23 is sandwiched between the array substrate 21, the counter substrate 22, and the sealing material 31.

  The layer thickness of the second liquid crystal layer 23 is 5.0 μm. A predetermined chiral material is added to the liquid crystal material constituting the second liquid crystal layer 23 so as to obtain the following characteristics. The difference in refractive index anisotropy (Δn) of the liquid crystal material is 0.092 for a wavelength of 590 nm. The twist angle of the liquid crystal molecules is 90 °, and the twist pitch is 60 μm. The twist of the liquid crystal molecules is counterclockwise.

  In the display region R2, a color filter having a plurality of colored layers of red, green, and blue (not shown) is disposed on one of the array substrate 21 and the counter substrate 22. For this reason, the liquid crystal display panel 3 can perform color display.

  A first polarizing plate 41 is disposed on the outer surface (outer surface side) of the array substrate 21, and a second polarizing plate 42 is disposed on the outer surface (outer surface side) of the second substrate 12. The first polarizing plate 41 and the second polarizing plate 42 are arranged in crossed Nicols. For this reason, the liquid crystal display panel 3 becomes normally white display which becomes black display in a voltage application state.

  The backlight unit 51 is provided on the outer surface side of the array substrate 21. The backlight unit 51 includes a light guide 52 that faces the first polarizing plate 41 and includes a light guide plate, a light source 53 that is disposed to face one side edge of the light guide, and a reflection plate 54. Yes.

  The backlight unit 51 includes a highly condensing prism sheet 55 (FIGS. 10 and 11) disposed to face the surface of the light guide 52. The prism sheet 55 has a function of increasing the parallelism (directivity) of the backlight light emitted from the light guide 52. The prism sheet 55 has a structure in which the degree of parallelism is higher than that of a prism sheet normally used in a liquid crystal display device for a notebook PC (personal computer). As the prism sheet 55, for example, a collimation sheet manufactured by Nagase Sangyo Co., Ltd. that has a very high degree of parallelism of the emitted backlight light is used.

  The luminance viewing angle control liquid crystal element 4 is disposed between the backlight unit 51 and the first polarizing plate 41. The luminance viewing angle control liquid crystal element 4 includes a fifth substrate 81, a sixth substrate 82, and a third liquid crystal layer 83. The fifth substrate 81 includes a glass substrate 84a as a transparent insulating substrate, a third electrode 85a formed on the glass substrate, and an alignment film 86a formed on the glass substrate including the third electrode. is doing. The sixth substrate 82 includes a glass substrate 84b as a transparent insulating substrate, a fourth electrode 85b formed on the glass substrate, and an alignment film 86b formed on the fourth electrode and the glass substrate. ing. The third electrode 85a and the fourth electrode 85b are formed of a transparent conductive material such as ITO. The alignment film 86a and the alignment film 86b are rubbed.

  The fifth substrate 81 and the sixth substrate 82 are opposed to each other with a predetermined gap held by a plurality of third spacers 87. The fifth substrate 81 and the sixth substrate 82 face the third electrode 85a and the fourth electrode 85b, and can control the diffusion state of light emitted from the backlight unit that transmits the luminance viewing angle control liquid crystal element 4. A light diffusion control region R4. In this embodiment, the light diffusion control region R4 overlaps the display region R2 described above.

  The fifth substrate 81 and the sixth substrate 82 are bonded to each other by a sealing material 88 disposed on the outer peripheral portion of both substrates outside the light diffusion control region R4. The third liquid crystal layer 83 is sandwiched between the fifth substrate 81, the sixth substrate 82, and the sealing material 88.

  Here, the third liquid crystal layer 83 according to this embodiment will be described. The layer thickness of the third liquid crystal layer 83 is 25 μm. The third liquid crystal layer 83 is made of a liquid crystal material in which 2 wt% of a photocrosslinkable polymer is dissolved in nematic liquid crystal having a refractive index anisotropy difference (Δn) of 0.23. The liquid crystal material of the third liquid crystal layer 83 is a transparent liquid at room temperature.

  When the third liquid crystal layer 83 is filled between the fifth substrate 81, the sixth substrate 82, and the sealing material 88, the filling can be performed by using a vacuum injection method or the like as in the conventional liquid crystal injection method. Therefore, the liquid crystal is filled in a liquid state. The filled liquid crystal is irradiated with ultraviolet rays to form a polymer (polymer network) and to deposit liquid crystal molecules. The alignment of the liquid crystal molecules in the third liquid crystal layer 83 can be regarded as almost random. The refractive index of the formed polymer is equal to the ordinary refractive index of the deposited liquid crystal molecules.

The fifth substrate 81 of the luminance viewing angle control liquid crystal element 4 configured as described above is disposed so as to face the backlight unit 51. The sixth substrate 82 is disposed to face the first polarizing plate 41. Here, the sixth substrate 82 may be bonded to the first polarizing plate 41 through, for example, glue (not shown).
The drive unit 5 drives the liquid crystal display panel 3 to control the display state. The drive unit 5 drives the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 in accordance with the display mode pattern.

  Here, the inventors of the present application applied a driving voltage to the phase control liquid crystal element 1 and applied no driving voltage to the luminance viewing angle control liquid crystal element 4, and a luminance viewing angle without applying a driving voltage to the phase control liquid crystal element. Displaying an image using a liquid crystal display device in two ways: applying a drive voltage to the control liquid crystal element, investigating various display characteristics such as luminance viewing angle, contrast viewing angle, front luminance, and front contrast characteristics, and consumption The power was measured.

  At that time, the driving unit 5 drives the liquid crystal display panel 3 with a driving voltage of 4 V via the TFT. When applying a driving voltage to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, the driving unit 5 applies the driving voltage 5V and then holds the voltage at 3V using hysteresis to drive the phase control liquid crystal element. The luminance viewing angle control liquid crystal element is driven with a driving voltage of 4V. The backlight unit 51 was turned on, and the liquid crystal display device was placed in an environment with an illuminance of 0 lx (lux).

  First, after applying a driving voltage of 5V to the phase control liquid crystal element 1 (between the first electrode 16a and the second electrode 16b), the driving voltage is lowered using hysteresis to maintain the application of 3V, and the luminance viewing angle. Various display characteristics and power consumption in the first pattern display mode in a state where the drive voltage is not applied to the control liquid crystal element 4 (between the third electrode 85a and the fourth electrode 85b) will be described.

A viewing angle having a luminance of 30 cd / m ² or more is as wide as ± 60 ° in the left-right direction, and a viewing angle with a contrast ratio of 10: 1 or more is sufficiently wide as ± 80 ° in the left-right direction. Further, the front luminance is sufficiently high at 300 cd / m ² . From this, it can be seen that the same front luminance and luminance viewing angle as those obtained when an image is displayed using a liquid crystal display device configured without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 are obtained. . The front contrast is 500: 1, and a high value equivalent to that of a liquid crystal display device without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 is obtained. The power consumption in the first pattern display mode is 1.704W.

  Next, the driving voltage is not applied to the phase control liquid crystal element 1 (between the first electrode 16a and the second electrode 16b), and the luminance viewing angle control liquid crystal element 4 (between the third electrode 85a and the fourth electrode 85b) is applied. Various display characteristics in the second pattern display mode in a state where the drive voltage 4V is applied will be described.

A viewing angle having a luminance of 30 cd / m ² or more is sufficiently narrow as ± 20 ° in the left-right direction, and a viewing angle having a contrast ratio of 10: 1 or more is sufficiently narrow as ± 15 ° in the left-right direction. The viewing angle with a contrast ratio of 1: 1 or more is sufficiently narrow as ± 20 ° in the left-right direction, and the display cannot be discriminated at all when the viewing angle is 20 ° or more.

Further, the front luminance is 600 cd / m ² , and double front luminance can be obtained when an image is displayed using a conventional liquid crystal display device configured without the luminance viewing angle control liquid crystal element 4. Further, the front contrast is 1000: 1, and a higher value can be obtained than when the phase control liquid crystal element 1 is not provided or when no voltage is applied to the phase control liquid crystal element. The power consumption in the second pattern display mode is 1.705W.

Next, the n-type phase change mode that is the display mode of the phase control liquid crystal element 1 will be described.
As shown in FIG. 3, the display characteristics vary depending on the driving voltage (potential difference between the first electrode 16a and the second electrode 16b) applied to the phase control liquid crystal element 1, but particularly when the driving voltage is increased. Display characteristics are different even when descending. When the drive voltage increases, the display characteristics change as indicated by line l1, and when the drive voltage decreases, the display characteristics change as indicated by line l2. This change in display characteristics is also a change in the phase state of light transmitted through the phase control liquid crystal element 1 and is due to the action of the first liquid crystal layer 13.

The first liquid crystal layer 13, the driving unit 5 driving the former, and has a memory function of maintaining the phase state at the time of rise by using a hysteresis after changes when descending upon to-bottom drive voltage increase. More particularly, maintaining the first liquid crystal layer 13, after the drive voltage rises to voltage V _4, the voltage V _4, the phase state of at voltage V ₄ between the voltages V ₁ that is lowered from the voltage V ₄ is doing. In this embodiment, the phase is maintained at the voltage V ₂ while maintaining the phase at the time of the voltage V ₄ .

Voltages V ₁ is the threshold voltage capable of maintaining the phase state of at voltage V _4, the voltage V ₃ is the threshold voltage for obtaining the display characteristics of the line l2 (phase states). In this embodiment, the voltage _{V 1} was, 1.5V, the voltage _{V 2} is the 3V, the voltage _{V 3} is 4V, the voltage _{V 4} is the 5V. Needless to say, when hysteresis is used, it is not limited to V ₄ and may be increased to at least V ₃ .

  Further, since the display characteristic in the first pattern display mode is indicated by a line l2, it can be seen that the light transmitted through the phase control liquid crystal element 1 is diffused. It can be seen that in the second pattern display mode, the light transmitted through the phase control liquid crystal element 1 is focused, contrary to the first pattern display mode. As a result, it can be seen that an image display with a wide viewing angle is obtained in the first pattern display mode, and an image display with a high front luminance is obtained in the second pattern display mode.

  Next, the principle of controlling the viewing angle of the liquid crystal display device by controlling the phase state of the light transmitted through the phase control liquid crystal element by the phase control liquid crystal element 1 will be described with reference to FIGS.

Among the viewing angle characteristics, particularly important characteristics are contrast viewing angle characteristics and luminance viewing angle characteristics. Among these, the contrast viewing angle characteristic greatly depends on the viewing angle characteristic during black display. In the display mode using liquid crystal molecules 61 are aligned substantially vertically as TN mode, be a black display because, in a state where the liquid crystal molecules are aligned substantially vertically to obtain a good black color display characteristics Many. However, in a state where the liquid crystal molecules 61 are arranged almost vertically, a phase difference occurs in an oblique visual field. A phase difference obtained by multiplying the difference in refractive index anisotropy (Δn) of the liquid crystal material by the thickness of the liquid crystal layer and the viewing angle is generated.

  In the present embodiment, a phase difference of +480 nm (× viewing angle) is generated. However, since the phase difference (FIGS. 4 and 5) when no voltage is applied to the first liquid crystal layer 13 is −480 nm (× viewing angle), the phase difference combined with the phase difference of the second liquid crystal layer 23 is used. Becomes zero. As described above, by providing the phase control liquid crystal element 1 including the first liquid crystal layer 13, it is possible to widen the contrast viewing angle characteristics as compared with the case where the phase control liquid crystal element is not provided.

  On the other hand, in the state where the voltage is applied to the first liquid crystal layer 13 to release the shake of the liquid crystal molecules and the liquid crystal molecules are aligned substantially vertically (FIGS. 8 and 9), like the second liquid crystal layer 23, the positive uniaxial (+640 nm). For this reason, the phase difference combined with the phase difference of the second liquid crystal layer 23 is +1120 nm. As described above, by providing the phase control liquid crystal element 1 including the first liquid crystal layer 13, the contrast viewing angle characteristic can be remarkably narrowed as compared with a case where the phase control liquid crystal element is not provided.

Next, the principle that the luminance viewing angle control liquid crystal element 4 can control the luminance viewing angle of the liquid crystal display device by controlling the diffusion state of the light transmitted through the luminance viewing angle control liquid crystal element will be described with reference to FIGS. 10 and 11. explain.
In a state where the driving voltage is not applied to the luminance viewing angle control liquid crystal element 4 (FIG. 10), the alignment of the liquid crystal molecules 61 of the nematic liquid crystal is almost random. For this reason, the refractive index is the average of the ordinary light refractive index and the extraordinary light refractive index. On the other hand, the refractive index of the polymer 91 is equal to the ordinary light refractive index of the deposited liquid crystal molecules 61. Therefore, the difference in refractive index anisotropy (Δn) is half of the above difference in refractive index anisotropy (Δn), that is, about 0.115, and a difference in refractive index is generated.

  Since the polymer 91 has a random three-dimensional structure, the backlight light transmitted through the prism sheet 55 is diffused by the luminance viewing angle control liquid crystal element 4. Therefore, a wide luminance viewing angle can be obtained as in the case of using a conventional liquid crystal display device configured without providing the luminance viewing angle control liquid crystal element 4.

  In a state where a sufficient driving voltage is applied to the luminance viewing angle control liquid crystal element 4 (FIG. 11) so that the liquid crystal molecules 61 of the third liquid crystal layer 83 are aligned approximately vertically, the alignment of the liquid crystal molecules is approximately vertical. For this reason, the refractive index with respect to the traveling direction of the light incident on the third liquid crystal layer 83 is the ordinary light refractive index. On the other hand, the refractive index of the polymer 91 is equal to the ordinary light refractive index of the deposited liquid crystal molecules 61. Therefore, there is no difference in refractive index between the polymer 91 and the liquid crystal molecules 61, and the backlight light transmitted through the prism sheet 55 is transmitted through the luminance viewing angle control liquid crystal element 4 as it is.

  As described above, the light with high parallelism sufficiently enhanced by the prism sheet 55 can be emitted to the liquid crystal display panel 3 (FIG. 1). For this reason, a much narrower luminance viewing angle is obtained than when a conventional liquid crystal display device configured without the luminance viewing angle control liquid crystal element 4 is used. At this time, the front luminance is much higher than when the conventional liquid crystal display device is used because the luminance viewing angle is reduced.

  According to the liquid crystal display device including the phase control liquid crystal element 1 having the memory function and the luminance viewing angle control liquid crystal element 4 configured as described above, the voltage applied to the phase control liquid crystal element can be easily controlled. The viewing angle can be controlled. In the first pattern display mode with a wide viewing angle, the first liquid crystal layer 13 raises the driving voltage to 5V and then holds it at 3V to maintain the phase state at 5V. Since the voltage applied to the phase control liquid crystal element 1 in the first pattern display mode can be reduced, the power consumption can be reduced. Note that when the display mode pattern of the liquid crystal display device is controlled, it can be controlled with one switch or one volume without increasing the power consumption.

  The phase control liquid crystal element 1 has a first liquid crystal layer 13. The first liquid crystal layer 13 can control the phase difference and traveling direction of light transmitted through the phase control liquid crystal element 1. As described above, the phase control liquid crystal element 1 can also control the viewing angle and the contrast viewing angle.

  For this reason, even if it is used in public places such as mobile PCs, mobile phones, PDAs, electronic notebooks, and tablet PCs, it may be difficult for others to identify the display contents by switching the display mode pattern. The viewing angle can be narrowed, and the viewing angle can be widened when a display image is observed by a plurality of observers. As a result, it is possible to eliminate the worry of others looking into the display contents. It is also possible for a plurality of observers to view the display screen simultaneously and satisfactorily.

  In a liquid crystal display device that controls nematic liquid crystal from substantially vertical to horizontal alignment, tilt alignment and alignment with twist, such as MVA mode, twisted nematic mode (TN mode), homogeneous mode (HOMO mode), and hybrid aligned nematic mode. The first polarizing plate 41 and the second polarizing plate 42 are arranged so as to display black in a state where the nematic liquid crystal is aligned substantially vertically (voltage application state). In this state, the second liquid crystal layer 23 can be regarded as a substantially positive uniaxial crystal when viewed optically. Therefore, since a phase difference occurs in the visual field in the oblique direction of the display screen, the contrast ratio is lower than that observed from the front of the display screen.

  In the first liquid crystal layer 13, the difference in refractive index anisotropy (Δn) of the liquid crystal material is small, the twist pitch of the liquid crystal molecules is short, and the twist angle of the liquid crystal molecules is 450 °. The first liquid crystal layer 13 is sufficiently small in optical rotation as compared with the second liquid crystal layer 23. Therefore, the first liquid crystal layer 13 is a retardation plate that can be regarded as a negative uniaxial crystal in a state where no voltage is applied between the first electrode 16a and the second electrode 16b.

  Therefore, in this state, the first liquid crystal layer 13 compensates for the phase difference of the second liquid crystal layer 23 in a substantially vertically aligned state, thereby suppressing a decrease in contrast in the oblique visual field. In particular, when the absolute value of the phase difference of the second liquid crystal layer 23 and the absolute value of the phase difference of the first liquid crystal layer 13 match, the effect is maximized. Further, by making the twist directions of the first liquid crystal layer 13 and the second liquid crystal layer 23 coincide with each other, the first liquid crystal layer 13 acts to enlarge the left-right viewing angle of the liquid crystal display panel 3 (TN mode).

  The above-described effects are effective when the twist angle of the liquid crystal molecules of the first liquid crystal layer 13 is controlled as follows. The liquid crystal molecules are aligned substantially perpendicular to the planes of the first substrate 11 and the second substrate 12 in a state where a voltage is applied to the phase control liquid crystal element 1, and the twist angle 360 is applied in a state where no voltage is applied. When oriented more than °. Alternatively, the liquid crystal molecules are aligned substantially perpendicular to the planes of the first substrate 11 and the second substrate 12 without applying a voltage to the phase control liquid crystal element 1, and the twist angle of the liquid crystal molecules with the voltage applied. In this case, the orientation is 360 ° or more.

  The phase control liquid crystal element 1 is disposed between the liquid crystal display panel 3 and the second polarizing plate 42. Thereby, the 2nd polarizing plate 42 plays the role of a polarizer. In this case, it is desirable that the second sheet 14b, which is the display screen side, be pasted on the outer surface with a paste (not shown). If not attached, an air interface exists between the phase control liquid crystal element 1 and the second polarizing plate 42, and if the gap is narrow, Newton ring stripes will be visually recognized. Conversely, if the gap between the phase control liquid crystal element 1 and the second polarizing plate 42 is wide, a spacer or the like for maintaining the gap is required, and the thickness of the entire liquid crystal display device is increased.

  Similarly, it is desirable that the phase control liquid crystal element 1 and the liquid crystal display panel 3 are bonded together without providing a gap. When the first sheet 14a and the second sheet 14b of the phase control liquid crystal element 1 are made of flexible plastic or thin glass, the phase control liquid crystal element is attached to the liquid crystal display panel 3 via an adhesive (not shown). It ’s fine.

  By providing both the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, the contrast viewing angle and the luminance viewing angle can be controlled simultaneously. These controls can be freely performed in an analog manner between the widest viewing angle state and the narrowest viewing angle state by controlling the voltage applied to both liquid crystal layers. In a state where the viewing angle is controlled to be narrow by the luminance viewing angle control liquid crystal element 4 (a state where the third liquid crystal layer 83 is controlled to be transparent), the emitted light can be concentrated in the front direction of the display screen. In this case, since sufficient luminance can be obtained even if the backlight intensity is weakened, power consumption can be reduced.

  The alignment of the liquid crystal molecules in a state where no voltage is applied to the third liquid crystal layer 83 is random, and alignment control by the alignment films 86a and 86b is not necessary. However, it is desirable to provide the alignment films 86a and 86b in order to protect the third electrode 85a and the fourth electrode 85b and to improve the holding characteristics of the third liquid crystal layer 83. However, in this case, alignment treatment such as rubbing is not necessary.

  The first electrode 16a, the second electrode 16b, the third electrode 85a, and the fourth electrode 85b are each integrally formed. For this reason, the power consumption of the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 is sufficiently smaller than the power consumption of the liquid crystal display panel 3 and is easy to manufacture. For this reason, it is easy to configure the luminance viewing angle control liquid crystal element 4 using a plastic substrate or a thin glass instead of the glass substrates 84a and 84b. In this case, the thickness and weight of the entire liquid crystal display device can be further reduced.

  The phase control liquid crystal element 1 is configured by forming a first alignment film 17 a and a second alignment film 17 b in a conventional resistance detection type touch panel and sandwiching the first liquid crystal layer 13. Therefore, the phase control liquid crystal element 1 can be manufactured by a conventional resistance detection touch panel manufacturing process and members other than the processes related to the formation of the first alignment film 17a and the second alignment film 17b and the liquid crystal injection. . Therefore, the liquid crystal display device can be formed without increasing the weight and thickness. In addition, a liquid crystal display device can be formed with almost no increase in manufacturing cost.

  The phase control liquid crystal element 1 has a position information detection unit 2. For this reason, the position information detection part 2 can detect the position information of the pressed part of the input region R3 satisfactorily. The phase control liquid crystal element 1 is configured to sandwich the first liquid crystal layer 13, but can detect the position information of the pressed portion satisfactorily like a conventional resistance detection type touch panel.

  The first substrate 11 and the counter substrate 22 have a common substrate 71 and are configured by the same substrate. For this reason, the thickness and weight of the entire liquid crystal display device can be reduced.

  Next, a liquid crystal display device according to a second embodiment will be described. In this embodiment, other configurations are the same as those of the first embodiment described above, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

The liquid crystal display device includes a phase control liquid crystal element 1, a liquid crystal display panel 3, a first polarizing plate 41, a second polarizing plate 42, a backlight unit 51, a luminance viewing angle control liquid crystal element 4, and a driving unit 5.
The first alignment film 17a and the second alignment film 17b of the phase control liquid crystal element 1 are rubbed so that the pretilt angle is 5 °.

  The layer thickness of the first liquid crystal layer 13 is 5.0 μm. A predetermined chiral material is added to the liquid crystal material constituting the first liquid crystal layer 13 so as to obtain the following characteristics. The difference in refractive index anisotropy (Δn) of the liquid crystal material is 0.072 for a wavelength of 590 nm. The twist angle of the liquid crystal molecules is 450 ° and the twist pitch is 3.92 μm. The twist of the liquid crystal molecules is counterclockwise.

  The phase control liquid crystal element 1 has a position information detection function. The first liquid crystal layer 13 has a function of controlling the phase state of light transmitted between the first substrate 11 and the second substrate 12. The first liquid crystal layer 13 does not have the memory function described above.

The third liquid crystal layer 83 of the luminance viewing angle control liquid crystal element 4 will be described.
The layer thickness of the third liquid crystal layer 83 is 10.0 μm. The third liquid crystal layer 83 is obtained by adding 5 wt% of a chiral material to a material obtained by dissolving 2.0 wt% of a photocrosslinkable polymer (polymer) in a nematic liquid crystal having a refractive index anisotropy difference (Δn) of 0.21. It is composed of liquid crystal material.

  The above-mentioned chiral material is added to the liquid crystal material constituting the third liquid crystal layer 83 so as to obtain the following characteristics. The difference in refractive index anisotropy (Δn) of the liquid crystal material is 0.20 for a wavelength of 590 nm. The twist angle of the liquid crystal molecules is 10 rotations, and the twist pitch P is 1.0 μm.

  The product ΔnP of the refractive index anisotropy difference Δn and the twist pitch P is 0.2 μm, and the optical rotation is almost zero. The product nP of the average refractive index n and the twist pitch P is 1.5 μm, and the selective reflection wavelength is in the infrared region. The liquid crystal material of the third liquid crystal layer 83 is a transparent liquid at room temperature. When the liquid crystal material is injected between the fifth substrate 81 and the sixth substrate 82, it is performed in a liquid state using a conventionally known injection method such as a vacuum injection method.

  The display mode of the luminance viewing angle control liquid crystal element 4 is a polymer stabilized mode, and is officially a PSCT (Polymer Stabilized Cholesteric Texture) mode. The PSCT mode will be described later.

  Here, the inventors of the present application applied a drive voltage to the luminance viewing angle control liquid crystal element 4 without applying a drive voltage to the phase control liquid crystal element 1, and applied a drive voltage to the phase control liquid crystal element 4 to obtain a luminance viewing angle. Displaying an image using a liquid crystal display device in two ways, with no driving voltage applied to the control liquid crystal element, investigating various display characteristics such as luminance viewing angle, contrast viewing angle, front luminance, and front contrast characteristics, and consumption The power was measured.

  At that time, the driving unit 5 drives the liquid crystal display panel 3 with a driving voltage of 4 V via the TFT. When applying a driving voltage to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, the driving unit 5 drives the phase control liquid crystal element with the driving voltage 8V, applies the driving voltage 20V, and then uses hysteresis. The luminance viewing angle control liquid crystal element is driven at 3V. The backlight unit 51 was turned on, and the liquid crystal display device was placed in an environment with an illuminance of 0 lx (lux).

  First, the drive voltage is not applied to the phase control liquid crystal element 1 (between the first electrode 16a and the second electrode 16b) and the drive is performed to the luminance viewing angle control liquid crystal element 4 (between the third electrode 85a and the fourth electrode 85b). Various display characteristics and power consumption in the first pattern display mode in a state where the drive voltage is lowered using the hysteresis and the application of 3V is held after applying the voltage 20V will be described.

A viewing angle having a luminance of 30 cd / m ² or more is as wide as ± 60 ° in the left-right direction, and a viewing angle with a contrast ratio of 10: 1 or more is sufficiently wide as ± 80 ° in the left-right direction. Further, the front luminance is sufficiently high at 300 cd / m ² . From this, it can be seen that the same front luminance and luminance viewing angle as those obtained when an image is displayed using a liquid crystal display device configured without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 are obtained. . The front contrast is 500: 1, and a high value equivalent to that of a liquid crystal display device without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 is obtained. The power consumption in the first pattern display mode is 1.700 W.

  Next, the driving voltage 8V is applied to the phase control liquid crystal element 1 (between the first electrode 16a and the second electrode 16b), and the luminance viewing angle control liquid crystal element 4 (between the third electrode 85a and the fourth electrode 85b). Next, various display characteristics and power consumption in the second pattern display mode in a state where no drive voltage is applied will be described.

A viewing angle having a luminance of 30 cd / m ² or more is sufficiently narrow as ± 20 ° in the left-right direction, and a viewing angle having a contrast ratio of 10: 1 or more is sufficiently narrow as ± 15 ° in the left-right direction. The viewing angle with a contrast ratio of 1: 1 or more is sufficiently narrow as ± 20 ° in the left-right direction, and the display cannot be discriminated at all when the viewing angle is 20 ° or more.

Further, the front luminance is 600 cd / m ² , and double front luminance can be obtained when an image is displayed using a conventional liquid crystal display device configured without the luminance viewing angle control liquid crystal element 4. Further, the front contrast is 1000: 1, and a higher value can be obtained than when the phase control liquid crystal element 1 is not provided or when no voltage is applied to the phase control liquid crystal element. The power consumption in the second pattern display mode is 1.709 W.

Next, the PSCT mode that is a display mode of the luminance viewing angle control liquid crystal element 4 will be described.
As shown in FIG. 12, the display characteristics vary depending on the driving voltage (between the third electrode 85a and the fourth electrode 85b) applied to the luminance viewing angle control liquid crystal element 4, but particularly when the driving voltage increases and decreases. But the display characteristics are different. When the drive voltage increases, the display characteristics are maintained as indicated by the line l3, and when the drive voltage decreases, the display characteristics change as indicated by the line l4. This change in display characteristics is also a change in the diffusion state of light transmitted through the luminance viewing angle control liquid crystal element 4 and is due to the action of the third liquid crystal layer 83.

The third liquid crystal layer 83 has a memory function under the control of the drive unit 5 to maintain a diffusion state using hysteresis when the drive voltage drops. More particularly, the third liquid crystal layer 83, after the drive voltage rises to the voltage V _5, the voltage V between the voltage V ₃ which descends from the voltage V _5, the voltages V ₁ which is further lowered from the voltage V ₃ It maintains the state of diffusion at a voltage V ₃ at _2.

Voltages V ₁ is the threshold voltage capable of maintaining a diffusion of at voltage V _3, voltages V ₁ from the voltage V ₃ at the time of driving voltage falling the voltage can be sufficiently diffuse the light passing through the luminance viewing angle control liquid crystal element 4 And the voltage V ₄ is a threshold voltage for obtaining the display characteristic of the line 14. In this embodiment, the voltage _{V 1} was, 1V, the voltage _{V 2} above 3V, the voltage _{V 3} is 11V, the voltage _{V 4} is 15V, the voltage _{V 5} is the 20V. Needless to say, when using the hysteresis is not limited to V _5, it is sufficient to increase at least to V _4.

  Further, since the display characteristic in the first pattern display mode is indicated by a line l4, it can be seen that light transmitted through the luminance viewing angle control liquid crystal element 4 is diffused. In the second pattern display mode, it is understood that the light transmitted through the luminance viewing angle control liquid crystal element 4 is condensed, contrary to the first pattern display mode. As a result, it can be seen that an image display with a wide viewing angle is obtained in the first pattern display mode, and an image display with a high front luminance is obtained in the second pattern display mode.

  Next, the principle by which the luminance viewing angle control liquid crystal element 4 can control the luminance viewing angle of the liquid crystal display device by controlling the diffusion state of the light transmitted through the luminance viewing angle control liquid crystal element 4 will be described with reference to FIGS. 13 and 14. To do.

  A polymer 91 is formed on the third liquid crystal layer 83. The polymer 91 is formed by injecting a liquid crystal material between the fifth substrate 81 and the sixth substrate 82 and then irradiating the entire injected liquid crystal material with ultraviolet rays. Also, cholesteric liquid crystal is deposited.

After driving voltage applied to the luminance viewing angle control liquid crystal element 4 is raised at least to the voltage V _4, the voltage V ₃ which descends from the voltage V _4, the voltage V between the voltages V ₁ which is further lowered from the voltage V _{3 In the} state where the ₃ o'clock diffusion state is maintained (FIG. 13), the extending directions of the central axes of the plurality of liquid crystal molecules 61 arranged in a spiral manner of the cholesteric liquid crystal are almost random. The refractive index of the polymer 91 is equal to the ordinary light refractive index of the deposited liquid crystal molecules 61. For this reason, in the first pattern display mode, the backlight light transmitted through the luminance viewing angle control liquid crystal element 4 is diffused.

The extension direction of the central axis of the plurality of liquid crystal molecules 61 arranged in a spiral manner in a state where a driving voltage is applied to the luminance viewing angle control liquid crystal element 4 within a range of 0 V or 0 V to V ₃ (FIG. 14). Intersects the plane of the fifth substrate 81 and the plane of the sixth substrate 82 substantially perpendicularly. For this reason, in the second pattern display mode, the backlight light transmitted through the luminance viewing angle control liquid crystal element 4 is focused.

  According to the liquid crystal display device including the phase control liquid crystal element 1 configured as described above and the luminance viewing angle control liquid crystal element 4 having a memory function, it is easy to control the voltage applied to the luminance viewing angle control liquid crystal element. It is possible to control the luminance viewing angle. In the first pattern display mode in which the standard front luminance is obtained, the third liquid crystal layer 83 raises the drive voltage to 20V, and then holds it at 3V to maintain the diffusion state at 11V. Since the voltage applied to the luminance viewing angle control liquid crystal element 4 in the first pattern display mode can be reduced, the power consumption can be reduced.

  By providing both the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, the contrast viewing angle and the luminance viewing angle can be controlled simultaneously. The first liquid crystal layer 13 can control the phase difference and traveling direction of light transmitted through the phase control liquid crystal element 1. The phase control liquid crystal element 1 can control the viewing angle and the contrast viewing angle. For this reason, by changing the display mode pattern, the viewing angle is narrowed when it is difficult for others to identify the display content, and the viewing angle is widened when observing the display image with multiple observers. Can do.

  Next, a liquid crystal display device according to a third embodiment will be described. In this embodiment, other configurations are the same as those of the above-described embodiment, and the same reference numerals are given to the same portions, and detailed description thereof is omitted.

  The liquid crystal display device includes a phase control liquid crystal element 1, a liquid crystal display panel 3, a first polarizing plate 41, a second polarizing plate 42, a backlight unit 51, a luminance viewing angle control liquid crystal element 4, and a driving unit 5. The phase control liquid crystal element 1 is the same as the phase control liquid crystal element of the first embodiment and has a memory function. The luminance viewing angle control liquid crystal element 4 is the same as the luminance viewing angle control liquid crystal element of the second embodiment, and has a memory function.

  Here, the inventors of the present application have applied a driving voltage to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, and have not applied a driving voltage to the phase control liquid crystal element and the luminance viewing angle control liquid crystal element. In the two methods, an image was displayed using a liquid crystal display device, and various display characteristics such as a luminance viewing angle, a contrast viewing angle, a front luminance, and a front contrast characteristic were investigated, and power consumption was measured.

  At that time, the driving unit 5 drives the liquid crystal display panel 3 with a driving voltage of 4 V via the TFT. When applying a driving voltage to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, the driving unit 5 applies the driving voltage 5V and then holds the voltage at 3V using hysteresis to drive the phase control liquid crystal element. Then, after applying the driving voltage 20V, the luminance viewing angle control liquid crystal element is driven while maintaining the voltage 3V using hysteresis. The backlight unit 51 was turned on, and the liquid crystal display device was placed in an environment with an illuminance of 0 lx (lux).

  First, after applying a driving voltage of 5V to the phase control liquid crystal element 1 (between the first electrode 16a and the second electrode 16b), the driving voltage is lowered using hysteresis to maintain the application of 3V, and the luminance viewing angle. Various displays in the first pattern display mode in which the drive voltage is applied to the control liquid crystal element 4 (between the third electrode 85a and the fourth electrode 85b) and then the drive voltage is lowered using hysteresis to maintain the application of 3V. Characteristics and power consumption will be described.

A viewing angle having a luminance of 30 cd / m ² or more is as wide as ± 60 ° in the left-right direction, and a viewing angle with a contrast ratio of 10: 1 or more is sufficiently wide as ± 80 ° in the left-right direction. Further, the front luminance is sufficiently high at 300 cd / m ² . From this, it can be seen that the same front luminance and luminance viewing angle as those obtained when an image is displayed using a liquid crystal display device configured without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 are obtained. . The front contrast is 500: 1, and a high value equivalent to that of a liquid crystal display device without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 is obtained. The power consumption in the first pattern display mode is 1.704W.

  Next, the second pattern in a state where no driving voltage is applied to the phase control liquid crystal element 1 (between the first electrode 16a and the second electrode 16b) and the luminance viewing angle control liquid crystal element 4 (between the third electrode 85a and the fourth electrode 85b). Various display characteristics and power consumption in the display mode will be described.

A viewing angle having a luminance of 30 cd / m ² or more is sufficiently narrow as ± 20 ° in the left-right direction, and a viewing angle having a contrast ratio of 10: 1 or more is sufficiently narrow as ± 15 ° in the left-right direction. The viewing angle with a contrast ratio of 1: 1 or more is sufficiently narrow as ± 20 ° in the left-right direction, and the display cannot be discriminated at all when the viewing angle is 20 ° or more.

Further, the front luminance is 600 cd / m ² , and double front luminance can be obtained when an image is displayed using a conventional liquid crystal display device configured without the luminance viewing angle control liquid crystal element 4. Further, the front contrast is 1000: 1, and a higher value can be obtained than when the phase control liquid crystal element 1 is not provided or when no voltage is applied to the phase control liquid crystal element. The power consumption in the second pattern display mode is 1.700 W.

  According to the liquid crystal display device including the phase control liquid crystal element 1 configured as described above and the luminance viewing angle control liquid crystal element 4 having a memory function, it is easy to control the voltage applied to the phase control liquid crystal element. The viewing angle can be controlled, and the luminance viewing angle can be easily controlled by controlling the voltage applied to the luminance viewing angle control liquid crystal element 4.

  In the first pattern display mode in which the standard front luminance is obtained, the first liquid crystal layer 13 increases the drive voltage to 5V, and then holds it at 3V to maintain the phase state at 5V. The three liquid crystal layer 83 raises the driving voltage to 20V and then holds it at 3V to maintain the diffusion state at 11V. Since the voltage applied to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 in the first pattern display mode can be reduced, the power consumption can be reduced.

  By providing both the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, the contrast viewing angle and the luminance viewing angle can be controlled simultaneously. The first liquid crystal layer 13 can control the phase difference and traveling direction of light transmitted through the phase control liquid crystal element. The phase control liquid crystal element 1 can control the viewing angle and the contrast viewing angle. For this reason, by changing the display mode pattern, the viewing angle is narrowed when it is difficult for others to identify the display content, and the viewing angle is widened when observing the display image with multiple observers. Can do.

Next, as Comparative Example 1, a liquid crystal display device configured in the same manner as the liquid crystal display device according to the above-described embodiment is used except that the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 are excluded. Various display characteristics and power consumption of the luminance viewing angle, the contrast viewing angle, the front luminance, and the front contrast characteristic when an image is displayed will be described. A viewing angle having a luminance of 30 cd / m ² or more is as wide as ± 60 ° in the left-right direction, and a viewing angle with a contrast ratio of 10: 1 or more is ± 40 ° in the left-right direction. Further, the front luminance is sufficiently high at 300 cd / m ² . The front contrast is 500: 1. The power consumption during image display is 1.700 W.

  Next, as Comparative Example 2, in the liquid crystal display device, the display mode of the phase control liquid crystal element 1 is the p-type phase change mode, and the display mode of the luminance viewing angle control liquid crystal element 4 is the polymer network mode. Except for the (Polymer Network Liquid Crystal) mode, the liquid crystal display device according to the above-described embodiment is configured in the same manner. The phase control liquid crystal element 1 does not have a memory function for maintaining a phase state using hysteresis, and the luminance viewing angle control liquid crystal element 4 has a memory function for maintaining a diffusion state using hysteresis. Absent.

  Here, the inventors of the present application do not apply a driving voltage to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, and apply a driving voltage to the phase control liquid crystal element and the luminance viewing angle control liquid crystal element. In the two methods, an image was displayed using a liquid crystal display device, and various display characteristics such as a luminance viewing angle, a contrast viewing angle, a front luminance, and a front contrast characteristic were investigated, and power consumption was measured.

  At that time, the driving unit 5 drives the liquid crystal display panel 3 with a driving voltage of 4 V via the TFT. When a driving voltage is applied to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4, the driving unit 5 drives the phase control liquid crystal element with the driving voltage 8V and drives the luminance viewing angle control liquid crystal element with the driving voltage 4V. To do. The backlight unit 51 was turned on, and the liquid crystal display device was placed in an environment with an illuminance of 0 lx (lux).

First, various display characteristics and power consumption when no driving voltage is applied to the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 will be described.
A viewing angle having a luminance of 30 cd / m ² or more is as wide as ± 60 ° in the left-right direction, and a viewing angle with a contrast ratio of 10: 1 or more is sufficiently wide as ± 80 ° in the left-right direction. Further, the front luminance is sufficiently high at 300 cd / m ² . From this, it can be seen that the same front luminance and luminance viewing angle as those obtained when an image is displayed using a liquid crystal display device configured without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 are obtained. . The front contrast is 500: 1, and a high value equivalent to that of a liquid crystal display device without the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 is obtained. The power consumption without applying the drive voltage is 1.704 W.

Next, various display characteristics and power consumption in a state where the drive voltage 8V is applied to the phase control liquid crystal element 1 and the drive voltage 4V is applied to the luminance viewing angle control liquid crystal element 4 will be described.
A viewing angle having a luminance of 30 cd / m ² or more is sufficiently narrow as ± 20 ° in the left-right direction, and a viewing angle having a contrast ratio of 10: 1 or more is sufficiently narrow as ± 15 ° in the left-right direction. The viewing angle with a contrast ratio of 1: 1 or more is sufficiently narrow as ± 20 ° in the left-right direction, and the display cannot be discriminated at all when the viewing angle is 20 ° or more.

Further, the front luminance is 600 cd / m ² , and double front luminance can be obtained when an image is displayed using a conventional liquid crystal display device configured without the luminance viewing angle control liquid crystal element 4. Further, the front contrast is 1000: 1, and a higher value can be obtained than when the phase control liquid crystal element 1 is not provided or when no voltage is applied to the phase control liquid crystal element. The power consumption in the state where the drive voltage is applied is 1.715 W, which is larger than the case where the phase control liquid crystal element 1 and the luminance viewing angle control liquid crystal element 4 are not provided.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, as shown in FIG. 16, the liquid crystal display device includes a phase control liquid crystal element 1, a liquid crystal display panel 3, a first polarizing plate 41, a second polarizing plate 42, a backlight unit 51, and a driving unit 5. It ’s fine. The display mode of the phase control liquid crystal element 1 is an n-type phase change mode, and the phase control liquid crystal element only needs to have a memory function for maintaining a phase state using hysteresis.

  In the liquid crystal display device shown in FIG. 16, the first substrate 11 and the counter substrate 22 may have a common substrate 71 as shown in FIG. By configuring the first substrate 11 and the counter substrate 22 with the same common substrate 71, the thickness and weight of the entire liquid crystal display device can be reduced. When the position information detection function is not required, the phase control liquid crystal element 1 may be formed without providing the position information detection unit 2.

  In the embodiment described above, the display mode of the luminance viewing angle control liquid crystal element 4 is the PSCT mode. However, the display mode is not limited to this and may be a heat effect smectic mode or an optical writing cholesteric mode. That is, the luminance viewing angle control liquid crystal element 4 only needs to have a memory function for maintaining a diffusion state using hysteresis.

Sectional drawing of the liquid crystal display device which concerns on 1st, 2nd, 3rd embodiment of this invention. FIG. 2 is a schematic plan view of the phase control liquid crystal element shown in FIG. 1. The figure which showed the change of the display characteristic with respect to the drive voltage applied to the phase control liquid crystal element shown in FIG. 1 with the graph. FIG. 2 is a schematic cross-sectional structure diagram of the first liquid crystal layer in a state where no voltage is applied to the first liquid crystal layer shown in FIG. 1. The figure which shows the average refractive index ellipsoid of the liquid crystal molecule shown in FIG. FIG. 3 is a schematic sectional view of a second liquid crystal layer when liquid crystal molecules of the second liquid crystal layer shown in FIG. 1 are vertically aligned. The figure which shows the average refractive index ellipsoid of the liquid crystal molecule shown in FIG. FIG. 2 is a schematic cross-sectional structure diagram of a first liquid crystal layer in a state where a voltage is applied to the first liquid crystal layer shown in FIG. 1. The figure which shows the average refractive index ellipsoid of the liquid crystal molecule shown in FIG. FIG. 4 is a diagram for explaining a cross-sectional structure of a third liquid crystal layer and an optical path of light emitted from a backlight unit in a state where no voltage is applied to the third liquid crystal layer illustrated in FIG. 1. FIG. 4 is a diagram for explaining a cross-sectional structure of a third liquid crystal layer and an optical path of light emitted from a backlight unit in a state where a voltage is applied to the third liquid crystal layer illustrated in FIG. 1. The figure which showed the change of the display characteristic with respect to the drive voltage applied to the brightness | luminance viewing angle control liquid crystal element of the liquid crystal display device which concerns on 2nd Embodiment of this invention with the graph. The brightness viewing angle control liquid crystal element, after applying a V ₄ or more drive voltage shown in FIG. 12, the third liquid crystal layer in the state holding the driving voltage within a range from V ₁ to lower the voltage of V ₃ The figure for demonstrating the cross-section and the optical path of the light discharge | released from a backlight unit. The brightness viewing angle control liquid crystal element, the optical path of the light emitted from the cross-sectional structure and the backlight unit of the third liquid crystal layer in the state in which the drive voltage within a range from 0V or 0V as shown in FIG. 12 to V ₃ is applied The figure for demonstrating. The figure which showed the change of the display characteristic with respect to the drive voltage applied to the phase control liquid crystal element and luminance visual angle control liquid crystal element in the comparative example 2 of this invention with the graph. Sectional drawing which shows the modification of the liquid crystal display device which concerns on embodiment of this invention. Sectional drawing which shows the other modification of the liquid crystal display device which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Phase control liquid crystal element, 2 ... Position information detection part, 3 ... Liquid crystal display panel, 4 ... Luminance viewing angle control liquid crystal element, 11 ... 1st board | substrate, 12 ... 2nd board | substrate, 13 ... 1st liquid crystal layer, 14a ... 1st 1 sheet, 14b ... 2nd sheet, 15a, 15b ... 1st resistance detection electrode, 15c, 15d ... 2nd resistance detection electrode, 16a ... 1st electrode, 16b ... 2nd electrode, 21 ... Array substrate, 22 ... Opposite substrate , 23 ... second liquid crystal layer, 41 ... first polarizing plate, 42 ... second polarizing plate, 51 ... backlight unit, 81 ... fifth substrate, 82 ... sixth substrate, 83 ... third liquid crystal layer, 84a ... glass Substrate, 84b ... glass substrate, 85a ... third electrode, 85b ... fourth electrode.

Claims (9)

A liquid crystal display panel, comprising: an array substrate; a counter substrate disposed opposite to the array substrate with a predetermined gap; and a first liquid crystal layer sandwiched between the array substrate and the counter substrate;
A first substrate having a first alignment layer that overlaps the first electrode and the first electrode, and a first substrate that is opposed to the first substrate with a predetermined gap, and that overlaps the second electrode and the second electrode. And a second substrate having a second alignment film opposed to the first alignment film, and a potential difference between the first substrate and the second substrate and the potential difference between the two substrates being increased The phase difference of the light transmitted between the two substrates differs between the first potential difference and the first potential difference, and then the first potential difference and the first potential difference that has decreased from the first potential difference. A second liquid crystal layer that maintains the phase state at the time of the first potential difference between two potential differences, and is provided to face the counter substrate of the liquid crystal display panel and transmits between the substrates The phase state of the image is controlled based on the potential difference. In the liquid crystal display device characterized in that it comprises a phase control liquid crystal element for controlling the viewing angle, a. The potential difference between the first substrate and the second substrate, after raising up the first potential difference, characterized in that it comprises a first potential difference, the driving portion for holding between the second potential difference The liquid crystal display device according to claim 1. A liquid crystal display panel, comprising: an array substrate; a counter substrate disposed opposite to the array substrate with a predetermined gap; and a first liquid crystal layer sandwiched between the array substrate and the counter substrate;
A first substrate having a first electrode and a first alignment film overlying the first electrode, a first electrode, a second electrode, and the second electrode, disposed opposite to each other with a predetermined gap therebetween And a second substrate having a second alignment film opposite to the first alignment film, and sandwiched between the first substrate and the second substrate, and the potential difference between the two substrates is increased The phase difference of the light transmitted between the two substrates is different between the potential difference after the decrease and the potential difference after the decrease, and after the potential difference has increased to the first potential difference, the first potential difference and the first potential difference have decreased. And a second liquid crystal layer that maintains the phase state at the time of the first potential difference , and is provided to face the counter substrate of the liquid crystal display panel and transmits between the substrates. The phase state of the light to be controlled based on the potential difference A phase control liquid crystal element for controlling the viewing angle by,
A third substrate having a third electrode and a third alignment film overlapping with the third electrode, a third electrode being opposed to the third substrate with a predetermined gap, and a fourth electrode and the fourth electrode And a fourth substrate having a fourth alignment film opposite to the third alignment film and sandwiched between the third substrate and the fourth substrate, and the potential difference between the two substrates is increased And the potential difference after the decrease, the diffusion state of the light transmitted between the two substrates is different, the potential difference rises to the third potential difference, then drops from the third potential difference, and the first the diffusion condition of the third potential difference and the fourth potential as the diffusion state that is different from, in between the fifth potential difference further lowered from the fourth potential, the third liquid crystal to maintain the diffusion state during said fourth potential difference And a liquid crystal display panel assembly Liquid crystal display apparatus characterized by comprising a luminance viewing angle control liquid crystal element provided in Lee substrate and a counter. The potential difference between the first substrate and the second substrate, after raising up the first potential difference, said first potential difference holds between the second potential difference, between the third substrate and the fourth substrate 4. The liquid crystal display device according to claim 3 , further comprising: a drive unit that holds the potential difference between the fourth potential difference and the fifth potential difference after the potential difference is increased to the third potential difference . 5. . The phase control display mode of the liquid crystal element, a liquid crystal display device according to claim 1 or 3, characterized in that an n-type phase-change mode. The first electrode and the second electrode are each formed in a rectangular shape,
The phase control liquid crystal element is
An input region where the first electrode and the second electrode overlap;
A first resistance detection electrode connected to the first electrode and provided on each of a pair of opposing sides of the first electrode; and positioned perpendicular to the first electrode; and to the second electrode And a second resistance detection electrode provided on each of a pair of opposing sides of the second electrode, and a position information detection unit for detecting position information of a pressed portion of the input region, the liquid crystal display device according to claim 1 or 3, characterized in that it comprises a. A backlight unit disposed opposite to the array substrate and emitting light with high parallelism to the array substrate;
A first polarizing plate disposed between the array substrate and the backlight unit;
The liquid crystal display device according to claim 1, further comprising: a second polarizing plate disposed on an outer surface side of the second substrate. A backlight unit disposed opposite to the luminance viewing angle control liquid crystal element and emitting light with high parallelism to the luminance viewing angle control liquid crystal element;
A first polarizer disposed between the beauty array substrate Oyo said luminance viewing angle control liquid crystal element,
The liquid crystal display device according to claim 3, further comprising: a second polarizing plate disposed on an outer surface side of the second substrate. Wherein the first substrate and the counter substrate, the liquid crystal display device according to claim 1 or 3, characterized in that it is composed of the same substrate.

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