JP4837796B2 - Transflective liquid crystal display device and portable terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transflective liquid crystal display device and a portable terminal device, with which a changeover of a viewing angle between a narrow viewing angle mode and a wide viewing angle mode is feasible. <P>SOLUTION: In a liquid crystal display element, a reflective section on which a projecting and recessing reflective pixel electrode conducting a display by reflecting light incident from a display surface side is formed, and a transmissive section on which a transmissive pixel electrode conducting a display by transmitting light emitted from a backlight is formed, are provided so as to each independently control voltages to be applied to a liquid crystal layer of the reflective section and that of the transmissive section. The reflective section has narrow viewing angle characteristics and the transmissive section has wide viewing angle characteristics, and a control section controls voltages applied to the liquid crystal layer independently for the reflective section and the transmissive section. The control section controls in such a way that in the wide viewing angle mode, the reflective section conducts a usual display and the transmissive section conducts a usual display; and in the narrow viewing angle mode, the reflective section conducts a usual display and the transmissive section conducts a dark display. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a transflective liquid crystal display device and a portable terminal device capable of switching a viewing angle between a narrow viewing mode and a wide viewing mode.

  Liquid crystal display devices are widely used for direct-view type monitors, projection-type projectors, and the like. Currently used liquid crystal display devices perform display by enclosing liquid crystal between two substrates and controlling the alignment state of the liquid crystal with an electric field applied to the liquid crystal.

  The liquid crystal display device has a transmissive liquid crystal display device in which light from the backlight transmits through the liquid crystal layer, a reflective liquid crystal display device in which light incident on the liquid crystal layer from the outside is reflected, and transmissive and reflective features. In addition, there is a transflective liquid crystal display device that transmits light from a backlight and reflects incident light from the outside.

  In particular, in mobile device applications such as cellular phones and PDAs (Personal Digital Assistance), transflective liquid crystal display devices having both transmissive image quality and reflective external light visibility have become mainstream. Further, the transflective liquid crystal display device is classified into an internal transflective type that reflects light inside the liquid crystal cell and an external transflective type that reflects light outside the liquid crystal cell.

  As an example of the internal transflective type, a liquid crystal display device disclosed in Patent Document 1 has been proposed. FIG. 25 is a cross-sectional view schematically showing a cross-sectional configuration of a conventional internal transflective liquid crystal display element based on FIG. 1 described in Patent Document 1. As shown in FIG. 25, a pair of substrates 102 is disposed on the backlight 109 so as to face each other, and a polarizing plate 101 is provided on a surface opposite to the facing surface of the substrate 102. The upper surface of the first substrate disposed on the backlight 109 side is composed of a reflection part 121 provided with an uneven reflection electrode (internal reflection plate) 120 and a transmission part 122 provided with an electrode 103. An electrode 103 is provided across the reflective portion 120 and the transmissive portion 121 on the opposite surface of the second substrate facing the substrate, and the liquid crystal layer 104 is sealed between the two substrates 102. That is, in the internal reflection type liquid crystal display device configured in this way, a reflection part 121 provided with a concavo-convex reflection electrode (internal reflection plate) 120 for reflecting incident light from outside in one pixel, and a back surface. A transmission part 122 for transmitting light of the light 109 is provided, and both reflected light and transmitted light can be used for display. In addition, since the suitable thickness of a liquid crystal differs in a reflection part and a permeation | transmission part, each liquid crystal thickness is often varied. In FIG. 25, on the substrate in the reflection portion, the interval between the uneven reflection electrode (internal reflection plate) 120 and the facing electrode 103 in the reflection portion 121 is smaller than the interval between the facing electrodes 103 in the transmission portion 122. Is provided with an insulating film 127, on which an uneven reflection electrode (internal reflection plate) 120 is formed.

  As an example of the external transflective type, there is a liquid crystal display device disclosed in Patent Document 2. FIG. 26 is a cross-sectional view schematically showing a cross-sectional configuration of a conventional external transflective liquid crystal display element based on FIG. 1 described in Patent Document 2. As shown in FIG. 26, a backlight 109 is provided in the liquid crystal display device, and a pair of substrates 102 is disposed on the backlight 109 so as to face each other. Each is provided with an electrode 103, and a liquid crystal layer 104 is sandwiched between the electrodes 103. A reflective polarizing plate 123 is provided on the surface of the substrate 102 arranged on the backlight 109 side on the backlight 109 side, and further, a polarizing plate 101 is provided so as to cover the surface of the reflective polarizing plate 123. . A polarizing plate 101 is also provided on the surface of the substrate 102 opposite to the substrate 109 on the side opposite to the backlight 109. In this conventional example, display is performed with light from the backlight 109 during transmissive display, and specific polarization of light incident from the display surface side is reflected by the reflective polarizing plate 123 during reflection display, and the reflected light is emitted to the viewer side. And display. In this case, the transmissive part and the reflective part are the same part, and one pixel becomes the transmissive part / reflective part 124. The method using a reflective polarizing plate in the conventional technique has a feature that the transmissive display and the voltage-transmittance (reflectance) curve of the reflective display are reversed.

  On the other hand, in the display element using the reflective polarizing plate disclosed in Patent Document 3, the voltage-transmittance (reflectance) curves of transmissive display and reflective display are aligned by using a retardation plate. A display element is described.

  As a liquid crystal display device employing another method of the external reflection method, there is a liquid crystal display device described in Patent Document 4. FIG. 27 is a cross-sectional view schematically showing a cross-sectional configuration of a conventional external transflective liquid crystal display element based on FIG. 15 described in Patent Document 4. As shown in FIG. 27, a pair of opposing substrates 102 are arranged above the backlight 109, electrodes 103 are provided on the opposing surfaces of the substrates, and the liquid crystal layer 104 is interposed between the electrodes 103. Is pinched. Further, a polarizing plate 101 is provided on a surface opposite to the facing surface of the pair of substrates 102. A transflective plate 125 is provided on the backlight side surface of the polarizing plate 101 on the backlight 109 side, and the liquid crystal display element constitutes a transmissive / reflective portion 126. That is, in the liquid crystal display element of the prior art, a transflective plate 125 is disposed between the polarizing plate 101 provided on the backlight 109 side and the backlight 109 instead of the polarizing reflector. In this case, unlike Patent Document 2, voltage-transmittance (reflectance) curves for transmissive display and reflective display are aligned.

  By the way, recently, a display device is required to have a secret protection function that prevents a person other than the person who is viewing the display device, that is, a person in the vicinity of the display device from seeing it. For example, in a financial terminal or the like known as ATM (Automated Teller Machine), it is necessary to touch a number button displayed on the display device and input a personal code number. You must avoid being visible. Similarly, a mobile phone or the like is required to have a function that can prevent display information from being viewed by others in the vicinity of the person. Furthermore, PDAs, notebook personal computers (hereinafter referred to as notebook PCs), and the like are also required to have a function for preventing others from seeing them when they are used in transportation such as trains. .

  On the other hand, it may be necessary to visually recognize the display device by a plurality of people. For example, when a television image is displayed on a screen with a mobile phone or the like, there are cases where it is desired to show it to a person in the vicinity in addition to the owner of the mobile phone. In some cases, the data screen of the notebook PC may be viewed by a plurality of people.

  Accordingly, the display device includes a narrow-field mode in which highly confidential information is viewed by individuals, and a wide-field mode in which highly open information is viewed by a plurality of people. In mobile phones, PDAs, notebook PCs, and the like, there is a demand for a display device that can switch between these display modes.

  The applicant has applied for a display device (Japanese Patent Application No. 2004-298571) that can switch between a narrow-field mode and a wide-field mode. FIG. 21 is a cross-sectional view schematically showing a cross-sectional configuration of the liquid crystal display device based on FIG. 1 attached at the time of this application. As shown in FIG. 21, in this liquid crystal display device, a backlight 109 that emits light in a planar shape is provided, and the direction of light incident from the backlight 109 is regulated on the backlight 109. A louver 106 that emits light is provided. In the louver 106, transparent regions 106a that transmit light and absorption regions 106b that absorb light are alternately arranged in a direction parallel to the surface of the louver 106. On the louver 106, a transparent / scattering switching element 107 that can be switched between a state of transmitting light incident from the louver 106 and a state of scattering is provided. In the transparent / scattering switching element 107, a polymer dispersed liquid crystal layer 105 in which a liquid crystal region 105b is dispersed in a polymer film 105a is sandwiched between a pair of electrodes 103 provided so as to cover the surface of the substrate 102. The polymer-dispersed liquid crystal layer 105 is in a state of transmitting incident light when no voltage is applied between the electrodes 103, and is incident when a voltage is applied between the electrodes 103. The scattered light is scattered. A liquid crystal panel 110 is provided on the transparent / scattering switching element 107. In the liquid crystal panel 110, a polarizing plate 101 that deflects light incident from the transparent / scattering switching element 107 is provided, and a substrate 102 is provided on the polarizing plate 101. An electrode 103 is provided over the substrate 102, and a liquid crystal layer 104 is provided so as to cover the surface of the electrode 103. An electrode 103 for applying a voltage to the liquid crystal layer is provided on the liquid crystal layer 104, and a substrate 102 is provided on the electrode. Further, a polarizing plate 101 that deflects light emitted from the liquid crystal panel is provided on the substrate 102.

  First, the operation in the narrow field mode will be described. In the narrow field mode, the transparent / scattering switching element 107 is in a transparent state. The light emitted from the backlight 109 is diffused light, but when entering the louver 106, the light spread in the light regulating direction is absorbed by the absorption region 106b, and the light emitted from the louver 106 is light having a highly directional distribution. It becomes. The light having a high directivity distribution is transmitted through the transparent / scattering switching element 107 in a transparent state, and emits light having a high directivity distribution. This highly directional distribution of light transmits through the liquid crystal panel 110 and emits highly directional distribution of light, resulting in a narrow-field display.

  Next, the operation in the wide viewing mode will be described. In the wide field mode, the transparent / scattering switching element 107 is in a scattering state. The light emitted from the backlight 109 is diffused light, but when entering the louver 106, the light spread in the light regulating direction is absorbed by the absorption region 106b, and the light emitted from the louver 106 is light having a highly directional distribution. It becomes. The light having a high directivity distribution is transmitted through the transparent / scattering switching element 107 in a scattering state, and is uniformly scattered, the directivity is lowered, and light having a wide-angle distribution is emitted. The wide-angle distribution light transmits through the liquid crystal panel 110 and emits the wide-angle distribution light, so that wide-field display is achieved. That is, in the apparatus shown in FIG. 21, the viewing angle is switched between the narrow viewing mode and the wide viewing mode by changing the angle distribution state of the light before passing through the liquid crystal panel.

  Moreover, there is a liquid crystal display device disclosed in Patent Document 5 as a display device that can switch between a narrow-field mode and a wide-field mode by a method different from the above. FIG. 22 is a plan view showing a pixel configuration of the liquid crystal display device described in Patent Document 5. FIG. FIG. 23 is a voltage-transmittance characteristic diagram in the wide field of view in the narrow field mode described in the document, and FIG. 24 is a voltage in the wide field of view in the wide field mode described in the document. -It is a transmittance | permeability characteristic figure.

  As shown in FIG. 22, the active matrix liquid crystal display device described in Patent Document 5 includes a plurality of pixels 111 arranged in a matrix with liquid crystal sandwiched between transparent electrodes, and each pixel 111 has a control line 116. The first pixel region 112 connected to the first pixel region, and the first pixel region includes a second pixel region 113 connected via a capacitor 114, and further includes the first pixel region 112 and the second pixel region. A switching element 115 is provided between the terminal 113 and the terminal 113.

  Here, the operation will be described assuming that the liquid crystal mode is a TN (Twisted Nematic) mode. In the narrow field mode, the switching element 115 is short-circuited. Since the first pixel region 112 and the second pixel region 113 are directly connected, the same voltage (V1) as that of the control line 116 is supplied to the first pixel region 112 and the second pixel region 113. Since the first pixel electrode in the first pixel region 112 and the second pixel electrode in the second pixel region 113 have the same voltage, they operate in the same manner as in the normal TN mode. As shown in FIG. 23, the voltage-transmittance curve 117a in the wide viewing area of the entire pixel 111 obtained by synthesizing the voltage-transmittance curves of the first pixel region 112 and the second pixel region 113 has a TN mode. The characteristic gradation inversion occurs.

  On the other hand, in the wide viewing mode, the switching element 115 is opened. Since the first pixel region 112 and the second pixel region 113 are connected via the capacitor 114, the drive voltage applied to the control line 116 is supplied to the first pixel region 112 as it is (voltage V1). ), The second pixel region 113 is supplied via the capacitor 114 (voltage V2), and the first pixel region 112 and the second pixel region 113 have different voltages. That is, the absolute value of the voltage is smaller in the second pixel voltage in the second pixel region 113 connected via the capacitor than in the first pixel voltage in the first pixel region 112 (| V1 |> | V2 |). As shown in FIG. 24, by applying different voltages to the liquid crystal molecules in the first pixel region 112 and the second pixel region 113, the voltage-transmittance curve 118 in the wide viewing area of the first pixel region 112 is obtained. The voltage-transmittance curve 119 in the wide field of view of the second pixel region 113 has a different waveform, and the voltage-transmittance curve of the first pixel region 112 and the voltage-transmittance of the second pixel region 113 are different. The voltage-transmittance curve 117b in the wide viewing area of the entire pixel 111 obtained by combining the curves is a smooth curve without gradation inversion.

  That is, in the technique described in Patent Document 5, the viewing angle switching between the narrow viewing mode and the wide viewing mode is performed by changing the voltage-transmittance characteristics of the pixels and changing the viewing angle characteristics of the liquid crystal panel. Table 1 summarizes the difference in voltage applied to the first pixel region and the second pixel region in the wide-field mode and the narrow-field mode. The voltages of the first pixel region and the second pixel region are different voltages in the wide field mode and the same voltage in the narrow field mode.

  Patent Document 6 describes a liquid crystal display device in which one pixel is composed of a plurality of sub-pixels having different alignment characteristics, and each sub-pixel is connected with a control line for controlling its operation independently. ing. Then, by the switching operation of the switch unit performed by the operator, a sub-pixel to which a display signal is applied through the control line group is selected from the pixels, and the viewing angle of the display pixel is set to a wide viewing angle and the Switch to a narrow viewing angle that makes it difficult to look into from the three parties.

Japanese Patent Laid-Open No. 11-242226 JP 2000-180819 A Japanese Patent Laid-Open No. 2000-193962 JP 2003-098325 A Japanese Patent Laid-Open No. 10-153968 JP 09-006289 A

  However, the above-described prior art has the following problems.

  In the viewing angle switching liquid crystal display device shown in FIG. 21, light having low directivity emitted from a backlight is converted into light having high directivity by a louver, and the light having high directivity is converted by a transparent / scattering switching element. Transmission or scattering is performed to switch between the narrow field mode and the wide field mode. Therefore, according to the present technique, the viewing angle can be switched in the transmissive display of the transmissive liquid crystal display device and the transflective liquid crystal display device. On the other hand, in the reflective display of the transflective liquid crystal display device, the light incident from the liquid crystal panel display surface is reflected by the reflector inside the liquid crystal cell in the internal transflective type and reflected from the liquid crystal cell in the external transflective type. The light is reflected on the viewer side by the plate and displayed with this light (reflected display light). In the internal transflective type, the transparent / scattering switching element is not included in the optical path of the reflected display light, and it is difficult to change the direction distribution of the reflected display light according to the present technology. Similarly, in the external transflective type in which the transparent / scattering switching element is provided between the external reflector and the backlight, it is difficult to change the direction distribution of the reflected display light. In the external transflective type in which the transparent / scattering switching element is provided between the external reflector and the liquid crystal panel, the optical path of the reflected display light includes the transparent / scattering switching element twice before and after the reflection, When the transparent / scattering switching element is in the scattering state, the intensity of the reflected display light is attenuated and darkened, which is not practical. Therefore, the viewing angle switching of the transflective liquid crystal display device having the reflective display portion is not supported.

  Further, in the liquid crystal display device described in Patent Document 5, in the narrow viewing angle mode of transmissive display, gradation inversion occurs with respect to a person viewing at a wide viewing angle. However, at a gradation reversal level, an observer with a wide viewing angle was visible depending on the display. Further, this method also does not describe the viewing angle switching of the reflective display, and does not support the viewing angle switching of the transflective liquid crystal display device. Also, the liquid crystal display device described in Patent Document 7 does not refer to the viewing angle switching of the reflective display, and does not correspond to the viewing angle switching of the transflective liquid crystal display device.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a transflective liquid crystal display device and a portable terminal device capable of switching the viewing angle between a narrow viewing mode and a wide viewing mode. .

  A transflective liquid crystal display device according to the present invention includes a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of substrates on which electrodes are formed, a backlight that emits light to the liquid crystal panel, and an application to the liquid crystal layer A control unit that controls a voltage to be transmitted, and each pixel of the liquid crystal panel individually reflects and displays incident light from the display surface side, and transmits light emitted from the backlight. The reflective part has a wide viewing angle characteristic, the transmissive part has a narrow viewing angle characteristic, and the control part applies a voltage applied to the liquid crystal layer to the reflective part and the transmissive part. In the wide-field mode, the reflection unit performs normal display and the transmission unit performs normal display.In the narrow-field mode, the reflection unit performs dark display and the transmission unit is normal. By controlling to display, wide-field mode Door and performing the viewing angle switching of the narrow field of view mode.

  In the narrow field mode, the image pattern may be displayed by performing normal display instead of performing dark display at some of the reflective portions of the pixels. By displaying an image pattern that can be viewed from a wide viewing angle in the narrow viewing mode, the fashionability can be improved compared to the case where nothing can be seen.

  A transflective liquid crystal display device according to the present invention includes a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of substrates on which electrodes are formed, a backlight that emits light to the liquid crystal panel, and an application to the liquid crystal layer A control unit that controls a voltage to be transmitted, and each pixel of the liquid crystal panel individually reflects and displays incident light from the display surface side, and transmits light emitted from the backlight. A transmissive portion for displaying, the reflective portion has a narrow viewing angle characteristic, the transmissive portion has a wide viewing angle characteristic, and the control portion applies a voltage applied to the liquid crystal layer to the reflective portion and the transmissive portion. In the wide field mode, the reflective part performs normal display and the transmissive part performs normal display.In the narrow field mode, the reflective part performs normal display and the transmissive part is dark. By controlling to display, wide-field mode Door and performing the viewing angle switching of the narrow field of view mode.

  In the narrow field mode, the image pattern may be displayed by performing normal display instead of performing dark display in some of the transmission parts of the pixels. By displaying an image pattern that can be viewed from a wide viewing angle in the narrow viewing mode, the fashionability can be improved compared to the case where nothing can be seen.

  The display of the image pattern is preferably varied spatially, temporally, or spatiotemporally. Thereby, it is possible to prevent the original display contents from being visually recognized by getting used to the eyes.

  The reflective pixel electrode formed in the reflective portion and the transmissive pixel electrode formed in the transmissive portion are separately provided and connected to different TFTs (Thin Film Transistors), so that the liquid crystal in the reflective portion and the transmissive portion is provided. The voltage applied to the layer can be controlled independently.

  By separately providing the COM electrode formed in the reflection part and the COM electrode formed in the transmission part, the voltage applied to the liquid crystal layer in the reflection part and the transmission part can be controlled independently.

  The false information may use any of white luminance, intermediate luminance, or false color light. The false information only needs to be a display in which the original display content is not visible for a specific viewing angle or more. By displaying the false information, the original display content is not visually recognized from the wide viewing angle by the reflected light in the narrow viewing mode.

  In addition, a front light can be provided on the observer side. Thereby, even when external light is not present or weak, sufficient luminance is obtained by the front light, and switching of the viewing angle functions.

  A louver that emits light while regulating the direction of light incident from the backlight can be provided. Thereby, it is possible to improve the viewing angle characteristics of the narrow field of view in the transmission part.

  Further, a transparent / scattering switching element that can be switched between a state of transmitting incident light and a state of scattering of incident light can be provided and used. Thereby, the viewing angle of the transmissive part can be switched by the transparent / scattering switching element, and the viewing angle of the transmissive part can be efficiently switched by using the display switching of the reflecting part together.

  In the present invention, by using the transflective liquid crystal display device for the mobile terminal device, the user can set an optimal display state according to the usage environment of the mobile terminal device.

  According to the present invention, a wide-field mode and a narrow-field mode are provided by separately providing a reflective portion and a transmissive portion in each pixel of the liquid crystal display element, and independently controlling the voltage applied to the liquid crystal layer in the reflective portion and the transmissive portion. A transflective liquid crystal display device capable of switching the viewing angle with the mode can be provided. In addition, for an external transflective liquid crystal display device in which the liquid crystal display element is a reflective and transmissive part, a first display part that mainly uses reflective display in each pixel and a transmissive display are mainly used. And a semi-transmission capable of switching the viewing angle between the wide viewing mode and the narrow viewing mode by independently controlling the voltage applied to the liquid crystal layer in the first display portion and the second display portion. Type liquid crystal display device can be provided. According to the present invention, it is possible to switch the viewing angle of a transflective liquid crystal display device having a reflective display portion which has not been conventionally supported.

It is a curve which shows the viewing angle-luminance characteristic at the time of the narrow visual field mode in the 1st Embodiment of this invention. FIG. 10 is a cross-sectional view of an internal transflective liquid crystal display device according to a fifth embodiment of the present invention. (A) Operation in wide viewing mode, (b) Operation in narrow viewing mode. FIG. 10 is a cross-sectional view of an internal transflective liquid crystal display device according to a sixth embodiment of the present invention. (A) Operation in wide viewing mode, (b) Operation in narrow viewing mode. 1 is a cross-sectional view of an internal transflective liquid crystal display device according to a first embodiment of the present invention. It is the schematic of the TFT substrate side electrode and counter substrate side electrode in 1st Embodiment. (A) Plane schematic diagram of TFT substrate side electrode, (b) Plane schematic diagram of counter substrate side electrode. It is sectional drawing of the internal transflective liquid crystal display device which concerns on the 2nd Embodiment of this invention. It is the schematic of the TFT substrate side electrode and counter substrate side electrode in the 2nd Embodiment of this invention. (A) Plane schematic diagram of TFT substrate side electrode, (b) Plane schematic diagram of counter substrate side electrode. It is sectional drawing of the internal transflective liquid crystal display device which concerns on the 3rd Embodiment of this invention. It is the schematic of the TFT substrate side electrode in the 3rd Embodiment of this invention. It is sectional drawing of the internal transflective liquid crystal display device which concerns on the 4th Embodiment of this invention. It is the schematic of the TFT substrate side electrode in the 4th Embodiment of this invention. It is sectional drawing of the internal transflective liquid crystal display device which concerns on the 7th Embodiment of this invention. It is sectional drawing of the internal transflective liquid crystal display device which concerns on the 8th Embodiment of this invention. It is sectional drawing of the liquid crystal display device of an external transflective type provided with the polarizing reflective plate concerning the 9th Embodiment of this invention. It is sectional drawing of the external transflective-type liquid crystal display device provided with the transflective board which concerns on the modification of 9th Embodiment. It is operation | movement explanatory drawing per pixel of the viewing angle control part and display part in the wide visual field mode and narrow visual field mode of the 1st thru | or 4th and 9th embodiment of this invention. It is operation | movement explanatory drawing per pixel of the viewing angle control part in the narrow visual field mode of the 10th Embodiment of this invention, and a display part. It is operation | movement explanatory drawing per pixel of the viewing angle control part and display part in the wide visual field mode and narrow visual field mode of the 5th and 6th embodiment of this invention. It is operation | movement explanatory drawing per pixel of the viewing angle control part and display part in the narrow visual field mode of the 11th Embodiment of this invention. It is a perspective view which shows the portable terminal device carrying the liquid crystal display device which concerns on the 12th Embodiment of this invention. It is the schematic diagram which showed typically the cross-sectional structure of the liquid crystal display device based on FIG. 1 attached in the case of application of Japanese Patent Application No. 2004-298571. 10 is a plan view showing a pixel configuration of a liquid crystal display device described in Patent Document 5. FIG. FIG. 11 is a voltage-transmittance characteristic diagram in a wide visual field region in the narrow visual field mode described in Patent Document 5. FIG. 10 is a voltage-transmittance characteristic diagram in a wide viewing area in the wide viewing mode described in Patent Document 5. It is sectional drawing which showed typically the cross-sectional structure of the conventional internal transflective liquid crystal display element based on FIG. 1 of patent document 1. FIG. It is sectional drawing which showed typically the cross-sectional structure of the conventional external transflective liquid crystal display element based on FIG. 1 of patent document 2. FIG. FIG. 16 is a cross-sectional view schematically showing a cross-sectional configuration of a conventional external transflective liquid crystal display element based on FIG. 15 described in Patent Document 4.

  Hereinafter, a transflective liquid crystal display device and a mobile terminal device according to an embodiment of the present invention will be described in detail with reference to the drawings. First, a transflective liquid crystal display device according to a first embodiment of the present invention will be described. FIG. 4 is a cross-sectional view of the internal transflective liquid crystal display device according to the first embodiment, and FIG. 5 is a schematic diagram of the TFT substrate side electrode and the counter substrate side electrode in the first embodiment. is there. Further, Table 2 is a first operation explanatory diagram of the reflection part and the transmission part in the wide-field mode and the narrow-field mode of the first embodiment, and Table 3 is the wide-field mode and the narrow-field of the first embodiment. It is 2nd operation | movement explanatory drawing of the reflection part in a visual field mode, and a transmission part. FIG. 1 is a curve showing viewing angle-luminance characteristics in the narrow viewing mode in the first embodiment.

  First, the configuration of one pixel of the transflective liquid crystal display device according to the first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 4, a pair of substrates 12 are arranged on the upper side of the backlight 6 so as to face each other, and on the backlight 6 side of the substrate 12 arranged on the viewer side that is the emission direction of the backlight light. A COM electrode 13 is provided on the surface (this substrate is referred to as a counter substrate). Also, on the surface of the substrate 12 disposed on the backlight 6 side on the opposite substrate side, a concavo-convex reflective pixel electrode (internal reflector) 14 that reflects light incident from the observer side with a concavo-convex surface, A transmissive pixel electrode 15 that transmits light emitted from the backlight 6 is provided separately (this substrate is referred to as a TFT substrate). As described above, the liquid crystal panel of the liquid crystal display device according to the present embodiment includes the reflection portion 17 provided with the uneven reflection pixel electrode (internal reflection plate) 14 and the transmission portion 18 provided with the transmission pixel electrode 15. The liquid crystal layer 16 is sandwiched between the two substrates. However, since the optimum liquid crystal thickness is different between the reflective portion 17 and the transmissive portion 18, a step is provided along the TFT substrate. The distance between the pixel electrode 14 and the COM electrode 13 facing it is smaller than the distance between the transmissive pixel electrode 15 and the COM electrode 13 facing it, and the liquid crystal thickness of the reflecting portion 17 is reduced. In FIG. 4, the steps are formed on the TFT substrate, but may be provided on the counter substrate. The counter substrate and the TFT substrate are bonded to each other with the liquid crystal layer 16 interposed therebetween, and a polarizing plate 11 is provided on each surface opposite to the counter substrate side of the counter substrate and the TFT substrate.

  FIG. 5A is a schematic plan view of the TFT substrate side electrode, and illustrates the structure of the electrode on the TFT substrate shown in FIG. 4 from the upper surface side of the substrate. As shown in FIG. 5 (a), a concavo-convex reflective pixel electrode (internal reflector) 14 and a transmissive pixel electrode 15 are respectively formed in different regions partitioned by a data line 19 and a gate line 20 provided in a grid pattern. Has been placed. A concave / convex reflective pixel electrode TFT 21 is formed near the intersection of the data line 19 and the gate line 20 in the section where the concave / convex reflective pixel electrode (internal reflective plate) 14 is disposed. It is connected to the source electrode of the pixel electrode TFT21. Similarly, a transmissive pixel electrode TFT 22 is formed near the intersection of the data line 19 and the gate line 20 in the section where the transmissive pixel electrode 15 is disposed, and the transmissive pixel electrode 15 is connected to the source electrode of the transmissive pixel electrode TFT 22. That is, in order to enable different voltages to be applied to the reflection portion 17 where the uneven reflection pixel electrode (internal reflection plate) 14 is arranged and the transmission portion 18 where the transmission pixel electrode 15 is arranged, the uneven reflection pixel electrode 14 and the transmission pixel are applied. Different TFTs are connected to the electrodes 15. FIG. 5B is a schematic plan view of the counter substrate side electrode. As shown in FIG. 5, the COM electrode 13 on the counter substrate side is common to the reflection unit 17 and the transmission unit 18.

  Next, the operation of the first embodiment will be described with reference to FIG. 4, Table 2, and FIG. In the case of performing display using the transflective liquid crystal display device of the present invention, the light incident on the display surface from the viewer side in the reflector 17 passes through the liquid crystal layer 16 and then is an uneven reflective pixel electrode (internal reflector). 14, passes through the liquid crystal layer 16 again, exits from the display surface, and becomes display light. On the other hand, in the transmissive portion 18, the light emitted from the backlight 6 passes through the transmissive pixel electrode 15, passes through the liquid crystal layer 16, and then exits from the display surface to become display light. At this time, by independently controlling the voltage between the electrodes in the reflective portion 17 and the transmissive portion 18, the orientation of the liquid crystal in the reflective portion 17 and the transmissive portion 18 can be controlled, and the display state can be controlled. In addition, the transmissive portion has a wide viewing angle characteristic capable of wide field display alone.

  As shown in Table 2, in the wide viewing mode, the transmissive part performs normal display and the reflective part also performs normal display. On the other hand, in the narrow field mode, the transmissive part is normally displayed, but the reflective part is in a bright state (white display). At that time, as shown in FIG. 1, the luminance 2 of the reflection part is designed to be larger than the luminance 1 of the transmission part for a specific viewing angle or more (that is, the range 3 in which the viewing angle is limited). In the range 3 in which the viewing angle is limited, the display content of the transmissive part is not visible. That is, the reflection part can be expressed as a viewing angle control part, and the transmission part can be expressed as a display part. Therefore, it is possible to switch the viewing angle between the wide viewing mode and the narrow viewing mode by switching the display of the reflecting section (viewing angle control section).

  In addition, the reflection part at the time of the narrow-field mode is not limited to the bright state (white display) of R (red), G (green), and B (blue) three pixels, but may be intermediate luminance or false color display, and the viewing angle is limited. Within the range 3, it is only necessary that the display content of the transmission part is invisible.

  In the first embodiment, as shown in Table 3, in the wide viewing mode, the transmissive part may perform normal display and the reflective part may perform dark display (black display). In the case of Table 2, in the wide viewing mode, since the normal display is performed in the reflecting portion, the display contents can be visually recognized by external light. In the case of Table 3, in the wide viewing mode, The reflection part does not normally display, and it is difficult to visually recognize the display content by external light.

  The mode of the liquid crystal operated in a vertical electric field is preferably a VA (Vertical Alignment) mode with a wide viewing angle. In VA mode, MVA (Multi-domain Vertical Alignment) method, PVA (Patterned Vertical Alignment) method with multi-domain and reduced viewing angle dependence, and ASV (Advanced Super V: Advanced Super Vui) method etc. are mentioned. Further, the present invention can be suitably used for a film compensation TN mode liquid crystal display panel.

  Next, a second embodiment of the present invention will be described. In the first embodiment, the pixel electrodes of the reflective portion and the display portion on the TFT substrate are connected to different TFTs, and the voltages of the reflective portion and the display portion can be controlled independently. In the second embodiment of the present invention, the pixel electrode of the reflective part and the display part on the TFT substrate is common and is controlled by one TFT, while the COM electrode and the display part of the reflective part on the counter substrate are controlled. The COM electrodes are separated. FIG. 6 is a cross-sectional view of an internal transflective liquid crystal display device according to the second embodiment. FIG. 7 is a schematic view of the TFT substrate side electrode and the counter substrate side electrode in the second embodiment.

  The configuration of the second embodiment will be described with reference to FIGS. In FIG. 6, the same components as those in FIG. 4 are denoted by the same reference numerals, and also in FIG. 7, the same components as those in FIG. Is omitted. As shown in FIG. 6, the uneven reflection pixel electrode (internal reflection plate) 14 provided on the substrate 12 is short-circuited with the transmission pixel electrode 15 to constitute one pixel electrode 25. Accordingly, as shown in FIG. 7A, the number of TFTs connected to the pixel electrode 25 may be one pixel electrode TFT 26. On the other hand, as shown in FIG. 6 and FIG. 7, the counter substrate side is divided into a reflection part COM electrode 23 and a transmission part COM electrode 24 with respect to the reflection part 17 and the transmission part 18, and COM electrodes are formed. Different voltages can be applied.

  As described above, since the reflection part COM electrode 23 and the transmission part COM electrode 24 are separated, the voltages of the reflection part and the transmission part can be controlled independently, and the same operation as in the first embodiment is realized. Is done.

  Next, a third embodiment of the present invention will be described. In the first embodiment, the liquid crystal is operated in a vertical electric field. However, the third embodiment of the present invention is different in that the liquid crystal is operated in a horizontal electric field. FIG. 8 is a cross-sectional view of an internal transflective liquid crystal display device according to the third embodiment. FIG. 9 is a schematic view of the TFT substrate side electrode in the third embodiment.

  The configuration of the third embodiment will be described with reference to FIGS. In FIG. 8, the same components as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 8, a liquid crystal panel is provided on the backlight 6. On the substrate 12 disposed on the backlight 6 side, the reflection part 17 on which the internal reflection plate 41 is formed and the backlight is emitted. It comprises a transmission part 18 that transmits light. In an IPS (In Plane Switching) mode that operates in a horizontal electric field in a direction horizontal to the substrate, it is preferable that the liquid crystal interface is flat. Therefore, a flattening film 42 is formed on the internal reflector 41. Further, the reflective pixel electrode 40 and the COM electrode 13 are formed in a comb shape on the planarizing film 42, and the transmissive pixel electrode 15 and the COM electrode 13 are comb-shaped on the substrate 12 in the transmissive portion 18. It is formed in a tooth shape. FIG. 9 is a plan view of the structure of these electrodes from the top surface of the substrate. As shown in FIG. 9, the reflecting portion 17 and the transmitting portion 18 are partitioned by a data line 19 and a gate line 20 provided in a lattice shape, and electrodes are formed in a comb shape in each region. . In the present embodiment, the COM electrodes 13 of the reflection portion 17 and the transmission portion 18 are at the same potential, but the reflection pixel electrode 40 and the transmission pixel electrode 15 are connected to the reflection pixel electrode TFT21 and the transmission pixel electrode TFT22, respectively. The voltages of the reflection part 17 and the transmission part 18 can be controlled independently. Since it is possible to control the voltage of the reflection part and the transmission part independently, the same operation as the first embodiment is realized.

  The configuration and arrangement of the electrodes are slightly different, but the FFS (Fringe Field Switching) method and the AFFS (Advanced Fringe Field Switching) method are the same. Can also be suitably used.

  Next, a fourth embodiment of the present invention will be described. In the third embodiment, the pixel electrodes of the reflective part and the display part have TFTs, respectively, whereas in the fourth embodiment of the present invention, the pixel electrode of the reflective part and the display part is common, The difference is that the COM electrode of the part and the COM electrode of the display part are separated. FIG. 10 is a cross-sectional view of an internal transflective liquid crystal display device according to the fourth embodiment. FIG. 11 is a schematic view of the TFT substrate side electrode in the fourth embodiment.

  The configuration of the fourth embodiment will be described with reference to FIGS. In FIG. 10, the same components as those in FIG. 8 are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 10, in an IPS (In Plane Switching) mode that operates in a horizontal electric field in a direction horizontal to the substrate, it is preferable that the liquid crystal interface is flat. Therefore, a planarizing film 42 is formed on the internal reflector 41. It is filmed. Further, the pixel electrode 25 and the reflection portion COM electrode 23 are formed in a comb shape on the planarizing film 42, and the pixel electrode 25 and the transmission portion COM electrode 24 are formed on the substrate 12 in the transmission portion 18. Is formed in a comb-teeth shape. FIG. 11 shows a plan view of the structure of these electrodes from the top surface of the substrate. As shown in FIG. 11, the pixel electrode 25 is connected by a single pixel electrode TFT 26. On the other hand, the COM electrode is divided into the reflection part COM electrode 23 and the transmission part COM electrode 24 with respect to the reflection part 17 and the transmission part 18, and different voltages can be applied. Since it is possible to control the voltage of the reflection part and the transmission part independently, the same operation as the first embodiment is realized.

  Next, a fifth embodiment of the present invention will be described. In the first to fourth embodiments, false information is displayed on the viewing angle control unit in the narrow viewing mode, and the display content on the display unit is not visible at a certain viewing angle or more by the false information of the viewing angle control unit. On the other hand, in the fifth embodiment of the present invention, the viewing angle characteristics of the viewing angle control unit and the display unit are changed, and in the wide viewing mode, the viewing angle control unit and the display unit perform normal display, and the narrow viewing field. In the mode, the viewing angle control unit is dark-displayed, and the display unit with narrow viewing characteristics is normally displayed, so that the viewing angle is switched. FIG. 2 is a cross-sectional view of an internal transflective liquid crystal display device according to the fifth embodiment. Table 4 is an explanatory diagram of the operation of the reflection part and the transmission part in the wide field mode and the narrow field mode of the fifth embodiment.

  The configuration of the fifth embodiment will be described with reference to FIG. As shown in FIG. 2A, in the transflective liquid crystal display device according to the present embodiment, a backlight 6 is provided, and an internal transflective liquid crystal panel 4 is disposed on the backlight 6. Has been. Each pixel of the internal transflective liquid crystal display device is provided with a reflective portion provided with the internal reflector 5 and a transmissive portion through which light emitted from the backlight is transmitted. The reflective portion and the transmissive portion are different. A voltage can be applied. Further, the reflecting portion has a wide viewing angle characteristic capable of performing a wide viewing mode alone, and the transmitting portion has a narrow viewing angle characteristic capable of performing a narrow viewing mode independently.

  As shown in Table 4, in the wide viewing mode, normal display is performed by the reflection part and the transmission part. As shown in FIG. 2A, the reflected display light 8 reflected by the internal reflector 5 in the reflecting portion has a wide viewing angle characteristic, and is transmitted from the backlight 6 and transmitted through the liquid crystal panel 7. Has a narrow viewing angle characteristic. The reflected display light 8 and the transmissive display light 7 are combined to obtain a wide viewing angle characteristic. On the other hand, as shown in Table 4, in the narrow-field mode, the reflective part is darkly displayed and the normal part is displayed on the transmissive part. In this case, as shown in FIG. 2B, since the display is performed only with the viewing angle characteristic of the narrow-field display of the transmission part, the viewing angle characteristic of the narrow field of view is realized. Accordingly, it is possible to switch the viewing angle between the wide viewing mode and the narrow viewing mode by switching the display of the reflecting portion. Note that the viewing angle characteristic of the reflecting part may be a characteristic that provides a wide field of view when combined with the narrow visual field of the transmitting part. In the present embodiment, it is possible to replace the transmission unit that performs normal display in the wide viewing mode and the narrow viewing mode as the display unit, and the reflection unit used for viewing angle switching as the viewing angle control unit. Note that the viewing angle characteristics of the reflecting portion can be obtained arbitrarily depending on the design of the reflecting plate. The viewing angle characteristic of the transmissive portion with a narrow field of view can be obtained by using a backlight or louver with high directivity.

  Next, a sixth embodiment of the present invention will be described. In the fifth embodiment, the reflecting portion has a wide viewing angle characteristic, and the transmissive portion has a narrow viewing angle characteristic. In the sixth embodiment, the reflecting portion has a narrow viewing angle. It has a viewing angle characteristic, and the transmission part is different in that it has a wide viewing angle characteristic. FIG. 3 is a cross-sectional view of an internal transflective liquid crystal display device according to the sixth embodiment. Table 5 is an explanatory diagram of the operation of the reflection part and the transmission part in the wide-field mode and the narrow-field mode of the sixth embodiment.

  In the transflective liquid crystal display device according to this embodiment, a reflective portion and a transmissive portion are provided in one pixel, and different voltages can be applied to the reflective portion and the transmissive portion. Furthermore, the reflection part has a viewing angle characteristic of a narrow field display, and the transmission part has a viewing angle characteristic of a wide field of view. As shown in Table 5, in the wide viewing mode, normal display is performed by the reflection part and the transmission part. As shown in FIG. 3A, the reflected display light 10 reflected by the internal reflector 5 in the reflecting portion has a viewing angle characteristic of narrow-field display, and is transmitted through the liquid crystal panel emitted from the backlight 6. Part of the transmissive display light 9 has a viewing angle characteristic of wide-field display. The reflected display light 10 and the transmissive display light 9 are combined to obtain a viewing angle characteristic in a wide viewing mode. On the other hand, as shown in Table 5, in the narrow-field mode, the reflection part performs normal display and the transmission part performs dark display. As shown in FIG. 3B, since the display is performed only with the narrow viewing angle viewing angle characteristics of the reflecting portion, the viewing angle characteristics in the narrow viewing mode are obtained. Accordingly, the viewing angle can be switched between the wide viewing mode and the narrow viewing mode by switching the display of the transmission part. In the present embodiment, the reflection unit that performs normal display in the wide viewing mode and the narrow viewing mode can be read as a display unit, and the transmission unit used for viewing angle switching can be read as a viewing angle control unit.

  Next, a seventh embodiment of the present invention will be described. In the present embodiment, a transparent / scattering switching element and a louver are provided between the backlight and the backlight-side polarizing plate. FIG. 12 is a cross-sectional view of an internal transflective liquid crystal display device according to the seventh embodiment.

  As shown in FIG. 12, a backlight 6 is provided, and a louver 30 is provided on the backlight 6 so as to regulate and emit the light incident from the backlight 6. In the louver 30, transparent regions 30 a that transmit light and absorption regions 30 b that absorb light are alternately arranged in a direction parallel to the surface of the louver 30. On the louver 30, a transparent / scattering switching element 31 that can be switched between a state of transmitting light incident from the louver 30 and a state of scattering is provided. In the transparent / scattering switching element 31, a polymer dispersed liquid crystal 29 in which a liquid crystal region 29 b is dispersed in a polymer film 29 a is sandwiched between a pair of electrodes 28 provided so as to cover the surface of the substrate 27. ing. A liquid crystal panel is provided on the transparent / scattering switching element 31, and the configuration thereof is the same as the liquid crystal panel in the first embodiment, for example, and the same reference numerals as those of the liquid crystal panel shown in FIG. Description is omitted. In the present embodiment, since the transparent / scattering switching element 31 and the louver 6 are provided, the viewing angle can be switched regardless of the display of the reflection unit 17. In other words, in the first to fourth embodiments, the false information display of the reflecting portion is when there is no external light, or when the external light is weak, sufficient luminance cannot be obtained, and viewing angle switching does not function. However, in this embodiment, by using the method described in the specification attached to the above-mentioned application (Japanese Patent Application No. 2004-298571), even in such a case, Corner switching is possible.

  Further, in the wide field mode, the reflection unit 17 performs normal display or dark display, the transmission unit 18 performs normal display in a wide field (switched by the transparent / scattering switching element 31), and in the narrow field mode, the reflection unit. The viewing angle can also be switched by a method in which 17 performs dark display and the transmission unit 18 performs normal display with a narrow field of view (switched by the transparent / scattering switching element 31).

  That is, in the invention according to Japanese Patent Application No. 2004-298571, there is a possibility that the display content is visually recognized by the reflected display light in the narrow-field mode. However, according to the seventh embodiment of the present invention, It is possible to prevent the display contents from being visually recognized by the reflected display light.

  Next, an eighth embodiment of the present invention will be described. In the eighth embodiment, a front light is provided on the viewer side. FIG. 13 is a cross-sectional view of an internal transflective liquid crystal display device according to the eighth embodiment. As shown in FIG. 13, a backlight 6 is provided. On the backlight 6, for example, the liquid crystal panel according to the first embodiment is disposed. A front light 32 is provided on the liquid crystal panel, and light enters the liquid crystal panel. In the first to sixth embodiments, the normal display / bright display of the reflecting section does not provide sufficient luminance when there is no external light or the external light is weak, and the viewing angle switching functions. However, since the front light 32 is provided, sufficient luminance can be obtained by the front light 32 and the viewing angle switching functions.

  Further, when the viewing angle control unit displays a false color at the reflection unit, the front light may not be white light but may be false color light equivalent to the false color displayed by the viewing angle control unit. By making the false color displayed by the viewing angle control unit and the equivalent false color light of the front light, the light absorbed by the color filter of the reflection unit, which is the viewing angle control unit, is reduced, and the use efficiency of the front light is reduced. Therefore, if the false color display of the viewing angle control unit has the same luminance, the power consumption of the front light can be reduced.

  Next, a ninth embodiment of the present invention will be described. The ninth embodiment of the present invention is not an internal transflective type as described above but an external transflective type. FIG. 14 is a cross-sectional view of an external transflective liquid crystal display device including a polarizing reflector according to the ninth embodiment. FIG. 15 is a cross-sectional view of an external transflective liquid crystal display device including a transflective plate according to a modification of the ninth embodiment. Table 6 is a first operation explanatory diagram of the viewing angle control unit and the display unit in the wide viewing mode and the narrow viewing mode of the ninth embodiment. Table 7 is a second operation explanatory diagram of the viewing angle control unit and the display unit in the wide viewing mode and the narrow viewing mode of the ninth embodiment.

  First, the configuration of the ninth embodiment will be described with reference to FIG. As shown in FIG. 14, a backlight 6 is provided, and a liquid crystal element having a liquid crystal layer 16 sandwiched between a pair of opposing substrates 12 is disposed on the backlight 6. A phase difference plate 35 is provided on the upper surface of the substrate 12 disposed on the observer side, and a polarizing plate 11 is provided thereon. A reflective polarizing plate 36 that selectively reflects a predetermined deflection component of incident light incident from the display surface side is provided on the surface of the substrate 12 disposed on the backlight 6 side on the backlight 6 side. A retardation plate 35 is provided so as to cover the reflective polarizing plate 36, and a polarizing plate 11 is further provided so as to cover the retardation plate 35. The viewing angle control unit pixel electrode 33 and the display unit pixel electrode 34 are separately formed on the surface of the substrate 12 arranged on the backlight 6 side on the viewer side, and the substrate facing this substrate A common COM electrode 13 is formed on the 12 opposing surfaces.

  Next, the configuration of a modification of the ninth embodiment will be described with reference to FIG. Above the backlight 6, a pair of opposing substrates 12 are disposed, and a liquid crystal layer 16 is sandwiched between the substrates. Further, a polarizing plate 11 is provided on a surface opposite to the facing surface side of the pair of substrates 12. A transflective plate 39 is provided on the surface on the backlight side of the polarizing plate 11 provided on the backlight 6 side, and the liquid crystal display element constitutes a transmission / reflection part. The viewing angle control unit pixel electrode 33 and the display unit pixel electrode 34 are separately formed on the viewer side surface of the substrate 12 disposed on the backlight side, and the substrate 12 facing the substrate is formed. A common COM electrode 13 is formed on the opposite surface. FIG. 15 showing a modification of the ninth embodiment is substantially the same as the ninth embodiment except that a transflective plate 39 is used instead of the reflective polarizer 36 in FIG. The same.

  In the external transflective type, there is no difference between the reflective part and the transmissive part, and the transmissive part and the reflective part are integrated. However, in order to switch the viewing angle, a viewing angle control unit 37 that mainly uses reflective display and a display unit 38 that mainly uses transmissive display are provided in one pixel, and the viewing angle control unit 37 and the display unit 38 are different. In order to make it possible to apply a voltage, the pixel electrode is divided and TFTs are provided as in the first embodiment or the third embodiment, or as in the second embodiment or the fourth embodiment. The COM electrodes are divided and controlled independently.

  Next, the operation of the ninth embodiment will be described with reference to Table 6. As shown in Table 6, in the wide viewing mode, the display unit performs normal display, and the viewing angle control unit also performs normal display. On the other hand, in the narrow viewing mode, the display unit is normally displayed, but the viewing angle control unit is in a bright state. At that time, similarly to FIG. 1 showing the viewing angle-luminance characteristics in the first embodiment, by designing so that the luminance of the viewing angle control unit is larger than the luminance of the display unit above a specific viewing angle, Beyond a specific viewing angle, the display content on the display unit becomes invisible. Therefore, the viewing angle can be switched between the wide viewing mode and the narrow viewing mode by switching the display of the viewing angle control unit. Further, as shown in Table 7, in the wide viewing mode, the display unit may perform normal display, and the viewing angle control unit may perform dark display (black display).

  Note that the viewing angle switching unit in the narrow viewing mode is not limited to the bright state (white display) of RGB 3 pixels, but may be intermediate luminance or color display, and the display content of the display unit is within the range 3 in which the viewing angle is limited. It only needs to be invisible. Further, in the wide viewing mode, a display in which the viewing angle control unit of one pixel and the display unit are two pixels may be performed.

  Next, a tenth embodiment of the present invention will be described. In the first to fourth and ninth embodiments, false information is displayed by the viewing angle control unit for all the pixels of the liquid crystal panel in the narrow viewing mode. However, in the tenth embodiment of the present invention, the narrow information is displayed. Even in the viewing mode, the viewing angle control unit performs normal display or black display for some of the pixels of the liquid crystal panel.

  FIG. 16 is an explanatory diagram of operations in units of pixels of the viewing angle control unit and the display unit in the wide viewing mode and the narrow viewing mode of the first to fourth and ninth embodiments. FIG. 17 is an operation explanatory diagram for each pixel of the viewing angle control unit and the display unit in the narrow viewing mode of the tenth embodiment.

  As shown in FIG. 16A, in the first to fourth and ninth embodiments, in the wide viewing mode, the viewing angle control unit 37 of the pixel 45 performs normal display or display for all the pixels of the liquid crystal panel. The display is black, and the display unit 38 is a normal display. Also, as shown in FIG. 16B, in the narrow viewing mode, the viewing angle control unit 37 of the pixel 45 is false information display and the display unit 38 is normal display for all pixels of the liquid crystal panel.

  On the other hand, in the tenth embodiment of the present invention, in the wide viewing mode, the same operation as that in FIG. 16A is performed, but in the narrow viewing mode, as shown in FIG. In contrast, the viewing angle control unit 37 does not display false information, but some viewing angle control units 37 perform normal display or black display. At this time, when viewed from a wide-angle range in which the viewing angle is limited, the difference between normal display and false information display or black display and false information display of the viewing angle control unit is visually recognized. Therefore, in the narrow viewing mode, the image pattern can be visually recognized from a wide angle range in which the viewing angle is limited by changing the normal display or black display arrangement to the viewing angle control unit to an image pattern such as a pattern or a picture.

  When the image pattern that can be viewed from a wide angle range with a limited viewing angle is fixed and displayed in the narrow viewing angle mode in the above-mentioned method, it appears to be an image pattern at first. The display content of the display portion of the pixel performing display or black display can be visually recognized. In order to prevent this, the image pattern is moved, blinked, or another image pattern is displayed every certain time (FIG. 17B). That is, it is preferable that the image pattern produced by the normal display or black display arrangement of the viewing angle control unit in the narrow viewing mode is varied temporally, spatially, or spatiotemporally.

  Next, an eleventh embodiment of the present invention will be described. In the fifth and sixth embodiments, in the narrow field mode, the viewing angle control unit is darkly displayed for all the pixels of the liquid crystal panel. However, in the eleventh embodiment of the present invention, even in the narrow field mode. The viewing angle control unit normally displays a part of the pixels of the liquid crystal panel.

  FIG. 18 is a diagram for explaining the operation in units of pixels of the viewing angle control unit and the display unit in the wide viewing mode and the narrow viewing mode of the fifth and sixth embodiments. FIG. 19 is an operation explanatory diagram for each pixel of the viewing angle control unit and the display unit in the narrow field mode of the eleventh embodiment.

  As shown in FIG. 18A, in the fifth and sixth embodiments, in the wide viewing mode, the viewing angle control unit 37 of the pixel 45 is normal display for all pixels of the liquid crystal panel, and the display unit 38 is a normal display. As shown in FIG. 18B, in the narrow viewing mode, the viewing angle control unit 37 of the pixel 45 is in black display and the display unit 38 is in normal display for all the pixels of the liquid crystal panel.

  On the other hand, in the eleventh embodiment of the present invention, in the wide viewing mode, the same operation as in FIG. 18A is performed, but in the narrow viewing mode, the viewing angle control unit is darkly displayed for all the pixels of the liquid crystal panel. Instead, normal display is performed by some viewing angle control units (FIG. 19A). At this time, when viewed from a wide viewing angle, the difference between the normal display and the black display of the viewing angle control unit 37 is visually recognized. Accordingly, in the narrow viewing mode, the image pattern can be viewed when viewed from a wide viewing angle by changing the normal display arrangement to the viewing angle control unit 37 as an image pattern such as a pattern or a picture. Similarly to the tenth embodiment, the image pattern may be moved, blinked, or displayed with another image pattern at certain time intervals (FIG. 19B).

  FIG. 20 is a perspective view showing a portable terminal device equipped with a liquid crystal display device according to the twelfth embodiment of the present invention. As shown in FIG. 20, the liquid crystal display device 44 of the present invention is mounted on, for example, a mobile phone 43. The liquid crystal display device of the present invention can be suitably applied to a mobile device such as a mobile phone, and the display angle switching display of the display device mounted on the mobile device becomes possible. Note that the portable device can be applied not only to a cellular phone but also to various portable terminal devices such as a PDA, a game machine, a digital camera, and a digital video camera.

DESCRIPTION OF SYMBOLS 1; The brightness | luminance of a transmission part 2; The brightness | luminance of a reflection part 3; The range which restricted the viewing angle 4; Internal transflective liquid crystal panel 5; Internal reflection board 6; Backlight 7;
8; Reflected display light (wide field of view)
9: Transmitted display light (wide field of view)
10: Reflected display light (narrow field of view)
11; Polarizing plate 12; Substrate 13; COM electrode 14; Uneven reflection pixel electrode (internal reflection plate)
15; transmissive pixel electrode 16; liquid crystal layer 17; reflective portion 18; transmissive portion 19; data line 20; gate line 21;
22; Transmission pixel electrode TFT
23; Reflection part COM electrode 24; Transmission part COM electrode 25; Pixel electrode 26; Pixel electrode TFT
27; Substrate 28; Electrode 29; Polymer dispersed liquid crystal 29a; Polymer film 29b; Liquid crystal region 30; Louver 30a; Transparent region 30b; Absorbing region 31; Transparent / scattering switching element 32; Pixel electrode 34; Display unit pixel electrode 35; Retardation plate 36; Reflective polarizing plate 37; Viewing angle control unit 38; Display unit 39; Transflective plate 40; Reflective pixel electrode 41; Internal reflection plate 42; Mobile phone 44; Liquid crystal display device 45; Pixel 101; Polarizing plate 102; Substrate 103; Electrode 104; Liquid crystal layer 105; Polymer dispersed liquid crystal 105a; Polymer film 105b; Liquid crystal region 106; Louver 106a; Absorption region 107; Transparent / scattering switching element 109; Back light 110; Liquid crystal panel 111; Pixel 112; First The pixel region 113; the second pixel region 114; the capacitor 115; the switching element 116; the control line 117a; the voltage-transmittance curves of the pixel regions 112 and 113 in the narrow-field mode in the wide-field region. Voltage-transmittance curve 117b; voltage-transmittance curve 118 in the wide viewing area of the pixel 111 obtained by synthesizing the voltage-transmittance curves of the pixel areas 112 and 113 in the wide viewing mode 118; wide viewing field in the first pixel area 112 Voltage-transmittance curve 119; voltage-transmittance curve 120 in the wide field of view of the second pixel region 113; uneven reflective electrode (internal reflector)
121; reflective portion 122; transmissive portion 123; reflective polarizing plate 124; transmissive / reflective portion 125; transflective plate 126; transmissive / reflective portion 127; insulating film

Claims (12)

A liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of substrates on which electrodes are formed; a backlight that emits light to the liquid crystal panel; and a control unit that controls a voltage applied to the liquid crystal layer. In addition, each pixel of the liquid crystal panel individually includes a reflection unit that reflects and displays incident light from the display surface side, and a transmission unit that transmits and displays the light emitted from the backlight, and the reflection And the transmission unit has a narrow viewing angle characteristic, and the control unit independently controls the voltage applied to the liquid crystal layer with respect to the reflection unit and the transmission unit, thereby providing a wide field of view. In the mode, the reflective part performs normal display and the transmissive part performs normal display, and in the narrow field mode, the reflective part performs dark display and the transmissive part performs normal display. Switch viewing angle between mode and narrow field mode Transflective liquid crystal display device comprising and. A liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of substrates on which electrodes are formed; a backlight that emits light to the liquid crystal panel; and a control unit that controls a voltage applied to the liquid crystal layer. In addition, each pixel of the liquid crystal panel individually includes a reflection unit that reflects and displays incident light from the display surface side, and a transmission unit that transmits and displays the light emitted from the backlight, and the reflection A narrow viewing angle characteristic, the transmissive part has a wide viewing angle characteristic, and the control unit controls the voltage applied to the liquid crystal layer independently for the reflective part and the transmissive part, thereby In the mode, the reflective part performs normal display and the transmissive part performs normal display, and in the narrow field mode, the reflective part performs normal display and the transmissive part performs dark display. Switch viewing angle between mode and narrow field mode Transflective liquid crystal display device comprising and. 2. The transflective liquid crystal display device according to claim 1, wherein in the narrow-field mode, an image pattern is displayed by performing normal display instead of performing dark display at a part of the reflective portions of the pixels. 3. The transflective liquid crystal display device according to claim 2, wherein, in the narrow-field mode, an image pattern is displayed by performing normal display instead of performing dark display in a part of the transmission parts of the pixels. 5. The transflective liquid crystal display device according to claim 3, wherein the display of the image pattern in the narrow field mode fluctuates spatially, temporally, or spatiotemporally. The reflective pixel electrode formed in the reflective portion and the transmissive pixel electrode formed in the transmissive portion are separately provided and connected to different TFTs, and applied to the liquid crystal layer in the reflective portion and the transmissive portion. 6. The transflective liquid crystal display device according to claim 1, wherein a voltage to be controlled is controlled independently. By separately providing the COM electrode formed in the reflection part and the COM electrode formed in the transmission part, the voltage applied to the liquid crystal layer in the reflection part and the transmission part can be controlled independently. The transflective liquid crystal display device according to any one of claims 1 to 5, characterized in that: 8. The transflective liquid crystal display device according to claim 1, wherein the false information is a display using white luminance, intermediate luminance, or false color light. The transflective liquid crystal display device according to any one of claims 1 to 8, further comprising a front light on an observer side. The transflective liquid crystal display device according to any one of claims 1 to 9, further comprising a louver that regulates and emits light incident from a backlight. 11. The transflective liquid crystal display device according to claim 1, further comprising a transparent / scattering switching element capable of switching between a state of transmitting incident light and a state of scattering of incident light. A portable terminal device comprising the transflective liquid crystal display device according to claim 1.

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