JP2012064027A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of achieving reductions in thickness and cost by integrating a touch panel with a parallax barrier.SOLUTION: A lower substrate of a touch panel integrated type parallax barrier 16 is formed with Y axial electrodes 8 in a stripe state, and an upper substrate is formed with X electrodes 10 in the direction orthogonal to the Y axial electrodes 8. Further, the touch panel integrated type parallax barrier 16 is disposed on a display panel 17 in such a manner that a slit between the Y axial electrodes overlaps with a black matrix 14 of the display panel and the parallax barrier driving and the touch panel driving are alternately controlled.

Description

  The present invention relates to a display device used in an electronic device. Specifically, the present invention relates to a display device to which a touch panel and a parallax barrier function are added.

  In recent years, as an information input method of a liquid crystal display device, a liquid crystal display device in which a touch panel is installed on a display surface of a liquid crystal display panel and information can be directly input from a display screen has been put into practical use. It is actively used in station ticket machines and mobile phones.

  In addition, for the display of a three-dimensional image (hereinafter referred to as 3D), there are an active shutter glasses method in which 3D can be observed regardless of the viewing direction by wearing dedicated glasses, and a parallax barrier method in which 3D can be observed with the naked eye. It has been put into practical use and is actively used for movies, TV, mobile phones, digital cameras, and the like. A display device of a parallax barrier system has a configuration in which a parallax barrier is provided on an upper surface of the display device.

  FIG. 10 is a diagram for explaining the outline of the parallax barrier method, and shows a state in which the optical path of the display device reaches the left and right eyes when passing through the parallax barrier. FIG. 10A shows a case where the stripe light-shielding unit is at an optimal position with respect to the display device on the parallax barrier, and FIG. 10B shows the stripe light-shielding unit of the parallax barrier displayed on the display device. The case where it has shifted | deviated from the optimal position is shown.

  When a composite image of the right eye image 1 and the left eye image 2 is displayed as shown in FIG. 10A, the light 4 emitted from the right eye image through the slit of the stripe-shaped light shielding portion 5 is the right eye and the left eye. The light 3 coming out of the image reaches the left eye. As a result, the observer can recognize the display image as 3D.

  Further, as shown in FIG. 10B, when the stripe-shaped light-shielding portion 5 is displaced with respect to the display device, the respective lights divided to the left and right are shifted from the desired eye position. In this state, when the image is viewed at a desired eye position, the display quality of the 3D image is significantly deteriorated and may not be recognized as a 3D image.

  FIG. 11 is a diagram showing a configuration of a conventional parallax barrier. FIG. 11A is a cross-sectional view schematically showing a configuration of a conventional parallax barrier, and FIG. 11B is a front view.

  As shown in FIG. 11A, in the conventional parallax barrier, a liquid crystal layer 9 is provided between a lower substrate 7 having a lower polarizing plate 6 provided on the lower surface and an upper substrate 11 having an upper polarizing plate 12 provided on the upper surface. An X electrode 10 which is an upper substrate transparent electrode and a Y electrode 8 which is a lower substrate transparent electrode are formed on the lower substrate 7 and the upper substrate 11 on the liquid crystal layer 9 side, respectively. As shown in FIG. 11B, the X electrode 10 has a vertical stripe shape and the Y electrode has a surface shape. Thus, in the conventional parallax barrier, one of the transparent electrodes on the upper and lower substrates has a vertical stripe shape, and the transparent conductive film on the opposite substrate side is uniformly formed as a surface. By applying a voltage to the upper and lower substrates having such a configuration, a light shielding portion appears in a stripe shape.

  Conventionally, the touch panel function and the 3D display function have not been added to one display device, but in recent years, it has been studied to add these two functions to one display device.

  When a touch panel and a 3D function are added to one display panel, a liquid crystal display panel (hereinafter referred to as LCD) is often used as the display panel, and a resistive film type or a capacitance type is used for the touch panel as a 3D image. A parallax barrier method is often used for the display function. In this case, there are known a method in which a touch panel is attached to the front surface of the LCD and a parallax barrier is attached to the back surface, and a method in which the parallax barrier and the touch panel are sequentially attached to the front surface of the LCD from the LCD side.

  In addition, there are cases where a liquid adhesive or a sheet adhesive is used as the bonding method, but there is a possibility of bubbles and misalignment in the bonding process, and the touch panel and the parallax barrier are bonded twice. This risk is simply doubled. Thus, in order to reduce the risk of such bonding, it is known to use a resin in addition to the adhesive and perform highly accurate alignment (see, for example, Patent Document 2).

JP 2005-181410 A JP 2008-58861 A

  However, as shown in Patent Document 1 and Patent Document 2, when a touch panel function and a parallax barrier function are added to the LCD, the thickness and weight of the display device increase. Also in the manufacturing process, the bonding process becomes complicated, and the risk of bubbles and misalignment is doubled. Further, in the conventional configuration, a liquid crystal display panel driving circuit, a touch panel driving circuit, and a parallax barrier driving circuit are required individually, and there is a problem that costs increase.

  An object of the present invention is to integrate a touch panel and a parallax barrier so as to improve the thickness and weight of the display device, to reduce the risk of bonding, and to reduce the cost by using the touch panel and the parallax barrier as one drive circuit. At the same time, it is to provide a touch panel integrated parallax barrier that can be applied to a wide variety of display panels such as a plasma display and an organic EL display as well as an LCD.

  Transparent electrodes are formed in a stripe pattern on the substrate, and a stripe-shaped counter electrode is formed on the counter substrate so as to be orthogonal to the transparent electrode. These substrates are arranged so that the electrodes face each other, and a liquid crystal is provided between the substrates to form a touch panel integrated parallax barrier having a touch panel function and a parallax barrier function. The touch panel integrated parallax barrier is installed on the upper surface of the display panel. At this time, the slit of the transparent electrode of the touch panel integrated parallax barrier is installed so as to overlap the black matrix of the display panel. Furthermore, the transparent electrode and the counter electrode are respectively connected to a drive circuit, and a parallax barrier drive and a touch panel drive are alternately controlled, so that a 3D image is displayed and a touch position can be detected.

Furthermore, the touch panel integrated parallax barrier is disposed so as to overlap the black matrix of the display panel in the same direction as the slits of the transparent electrode.
Further, the drive circuit is provided with a touch signal detection unit and a parallax barrier drive unit.

  In addition, a driving signal transmitted to each of the transparent electrode and the counter electrode is provided with a parallax barrier driving period, a high impedance period, and a touch panel driving period. When the drive signal on one of the transparent electrode and the counter electrode is in the touch panel drive period, the other electrode is in a high impedance state.

  A display device having a touch panel and a parallax barrier function can be made thinner and lighter, and reliability can be improved and costs can be reduced.

It is a figure which shows typically the structure of a part of display apparatus of this invention. It is a figure explaining the structure of the display apparatus of this invention. It is a figure explaining the electrostatic coupling of the display apparatus of this invention. It is a figure which shows typically the drive circuit used for the display apparatus of this invention. It is a figure explaining the drive signal of the display apparatus of this invention. It is sectional drawing which shows the structure of the display apparatus of this invention typically. It is a figure which shows typically the drive circuit used for the display apparatus of this invention. It is a figure explaining the drive signal of the display apparatus of this invention. It is sectional drawing which shows the structure of the display apparatus of this invention typically. It is a figure explaining the outline of the display apparatus of a parallax barrier system. It is a figure which shows the structure of the conventional parallax barrier typically.

  In the display device of the present invention, a touch panel integrated parallax barrier having both a touch panel function and a parallax barrier function is installed on a display panel, and parallax barrier driving and touch panel driving are alternately controlled by switching a switch of a driving circuit. 3D image display and touch position are detected. In the touch panel integrated parallax barrier, liquid crystal is sealed between the substrate and the counter substrate, and the transparent electrode and the counter electrode are formed in stripes on the substrate and the counter substrate, respectively, so as to be orthogonal to each other. Furthermore, there is a slit between the transparent electrodes, and the touch panel integrated parallax barrier and the display panel are aligned so that the slit is parallel to and overlaps the black matrix. Further, the transparent electrode formed on the substrate has a stripe shape in the horizontal direction, and serves as a Y electrode for detecting the Y coordinate in the capacitive touch panel function. The counter electrode formed on the counter substrate has a stripe shape in the vertical direction, and is an X electrode for detecting the X coordinate in the capacitive touch panel function.

The configuration of the touch panel integrated parallax barrier according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating the configuration of a touch panel integrated parallax barrier used in the display device of the present invention. The configuration of the touch panel integrated parallax barrier of the present invention is significantly different from the conventional parallax barrier in the configuration of the transparent electrodes formed on the upper and lower substrates.

  2A is a cross-sectional view schematically showing the configuration of the touch panel integrated parallax barrier in the present invention, and FIG. 1B is a front view. As shown in FIG. 1A, the upper substrate 11 on which the X electrode 10 is formed and the lower substrate 7 on which the Y electrode is formed are arranged so that the electrodes face each other, and the liquid crystal layer 9 is provided between them. It is done. An upper polarizing plate 12 is provided on the upper surface of the upper substrate 11, and a lower polarizing plate 6 is provided on the lower surface of the lower substrate 7. When the LCD is used for the display panel, the lower polarizing plate 6 may also serve as the upper polarizing plate of the LCD.

  Further, as shown in FIG. 2B, the X electrode 10 and the Y electrode 8 on the upper and lower substrates are provided in stripes so as to be orthogonal to each other. In the touch panel integrated parallax barrier according to the present invention, the X electrode 10 is a transparent electrode formed in a vertical stripe pattern on the upper substrate 11, and the Y electrode 8 is formed in a horizontal stripe pattern on the lower substrate 7. Transparent electrode. Further, the width of the X electrode 10 and the gap between the electrodes (hereinafter referred to as slits) are determined by the dot pitch of the display panel to be bonded and the 3D viewing distance. The slits of the Y electrode 8 are preferably narrower than the width of the black matrix (hereinafter referred to as BM) of the display panel to be bonded.

  FIG. 2 is a top view illustrating the configuration of the display device 15 of the present invention. The touch panel integrated parallax barrier 16 described above is provided on the upper surface of the display panel 17. In the touch panel integrated parallax barrier 16 of the present invention, since slits are provided between the Y electrodes, there is a possibility that the slit portions are not shielded and a desired stripe-shaped shielded portion cannot be obtained. When the slit is overlapped so that the position of the BM 14 of the display panel 17 is aligned, when driven as a parallax barrier, the slit portion of the Y electrode is shielded from light by the BM 14 of the display panel. As a result, a stripe-shaped light shielding portion appears as in the conventional parallax barrier.

Next, driving of the touch panel integrated parallax barrier will be described with reference to FIGS.
FIG. 3 is a diagram showing a state of electrostatic coupling between the finger, the X electrode, and the Y electrode. When driven as a touch panel, each electrode functions as a capacitive system, and electrostatic coupling 19 occurs between the finger 18 and the Y electrode 8 at the pressed position, and between the finger 18 and the X electrode 10. Electrostatic coupling 20 occurs. At that time, a change in capacitance is detected via each electrode, an X coordinate is detected from the X electrode, and a Y coordinate is detected from the Y electrode.

  FIG. 4 is a diagram showing a touch panel integrated parallax barrier driving circuit. As shown in the figure, this circuit is formed of three main parts: an electrode part 21, a touch signal detection part 23, and a parallax barrier output part 25.

  The drive circuit is connected to the parallax barrier output buffer circuit 24 from the electrode unit 21 through SW1 and SW2, and is connected to the touch signal detection circuit 22 through SW1 and SW3. As a detection circuit method of the touch panel, a detection method generally proposed in a capacitance type touch panel such as a relaxation oscillation method, a charge transfer method, a CSA method, a CSD method, and a series capacitance / voltage division comparison method can be used.

  Next, the driving timing of the parallax barrier and the touch panel will be described with reference to FIG. FIG. 7 is a diagram illustrating driving signals for the parallax barrier and the touch panel.

  The touch panel integrated parallax barrier of the present invention is characterized in that the touch panel functions even while the parallax barrier is being driven. Therefore, the parallax barrier drive signal may affect the touch panel detection circuit as noise. Even when attention is paid only to the touch panel, the drive signal of the X electrode may affect the Y electrode as noise.

  As countermeasures against these noises, a parallax barrier driving period 26, a high impedance period 27, and a touch panel driving period 28 are provided in the driving signal. As shown in FIG. 6, when the Y electrode is in the touch panel drive period 28, the X electrode is set to the high impedance period 27 so that noise is not given to the Y electrode. Conversely, when the X electrode is in the touch panel drive period 28, the Y electrode is set to the high impedance period 27 so that noise from the Y electrode is not applied to the X electrode. When the Y electrode is in the parallax barrier driving period 26, the X electrode is also in the parallax barrier driving period 26.

  Here, when the Y electrode is driven on the touch panel, in the pressed portion, the Y electrode arranged at the position overlapping with the X electrode is difficult to detect because the capacitance is little changed, but the position overlapping with the slit of the X electrode. Capacitance change can be captured by the Y electrode arranged in the. Therefore, the pressed Y coordinate can be detected by adjusting the sensitivity of the Y electrode.

  The parallax barrier and the touch panel drive timing are controlled using the switches described in FIG. When driving the touch panel, SW1 and SW3 are connected and SW2 is opened. When the high impedance state is set, SW1 is opened. When the parallax barrier is driven, SW1 and SW2 are connected and SW3 is opened.

  As described above, in the touch panel integrated parallax barrier of the present invention, the parallax barrier driving and the touch panel driving are alternately performed, and the touch panel function can be used even while the observer recognizes 3D.

  In addition, according to the manufacturing method of the display device including the touch panel integrated parallax barrier of the present invention, the touch panel integrated parallax barrier and the display device having the above-described configuration are created and positioned, and then the touch panel integrated parallax is formed on the upper surface of the display device. Bond the barrier.

  In positioning, it is overlaid so that the slit between the Y electrodes of the touch panel integrated parallax barrier and the position of the BM of the display panel are aligned.

Further, as shown in FIG. 10B described above, when the stripe light-shielding portion of the parallax barrier is shifted from the optimal position with respect to the display device, the display quality of the 3D image is remarkably deteriorated and cannot be recognized as a 3D image. Therefore, in the manufacturing method of the present invention, an alignment mark is provided on the display device and the touch panel integrated parallax barrier before the bonding step. The alignment mark is designed so that the slit of the Y electrode is at the same position as the BM of the display panel. Then, positioning is performed by each alien mark to improve the bonding accuracy.
Embodiments of the present invention will be described below with reference to the drawings.

  The display device of the present embodiment will be described with reference to FIG. FIG. 6 schematically shows a cross-sectional configuration along the Y electrode of the display device 15 including the touch panel integrated parallax barrier of the present embodiment. In this embodiment, an LCD is used for the display panel.

  As shown in the figure, the LCD 30 has a liquid crystal layer 9 provided between a substrate 31 and a counter substrate 32, a lower polarizing plate for LCD 33 on the lower surface of the substrate, and an upper polarizing plate for LCD on the upper surface of the counter substrate. Provided. In the parallax barrier integrated with a touch panel, a lower substrate 7 on which a Y electrode 8 is formed and an upper substrate 11 on which an X electrode 10 is formed are arranged so that the electrodes face each other, and a liquid crystal layer is interposed between these substrates. 9 is provided. In this embodiment, the upper polarizing plate 12 is provided on the surface of the upper substrate 11, but the lower polarizing plate of the lower substrate 7 can be omitted. That is, in the present embodiment, the upper polarizing plate 34 of the LCD 30 can be used as the lower polarizing plate of the touch panel integrated parallax barrier. Further, an adhesive layer 13 is provided between the touch panel integrated parallax barrier and the LCD 30.

  Further, the X electrode 10 and the Y electrode 8 on the upper and lower substrates of the touch panel integrated parallax barrier are provided in stripes so as to be orthogonal to each other. At this time, the X electrode 10 is formed in a vertical stripe shape, and the Y electrode is formed in a horizontal stripe shape. The electrode width and slit of the X electrode 10 are determined by the dot pitch of the LCD to be bonded and the 3D viewing distance, and the slit of the Y electrode 8 is equal to or less than the BM width of the LCD 30.

Next, the driving circuit and the driving signal in this embodiment will be described with reference to FIGS.
FIG. 7 is a diagram schematically showing the circuit of this embodiment. The drive circuit of the present embodiment is roughly divided into three parts, that is, an electrode part 35, a parallax barrier output part 36, and a touch signal detection part 37, and each unit is connected via SW1, SW2, and SW3.

  The electrode part 35 is composed of an X electrode and a Y electrode. The parallax barrier output unit 36 includes a parallax barrier output buffer circuit 38 and SW2. When driving the parallax barrier, the parallax barrier output unit 36 connects SW1 and SW2, and signals from the parallax barrier output unit 36 via SW1 and SW2. To drive.

  Next, the touch signal detection unit 37 serving as a touch panel drive unit will be described. In the present embodiment, the charge transfer method is adopted for the touch panel drive unit because it has few external parts. However, the present invention is not limited to this, and other detection circuits such as a relaxation oscillation method, a CSA method, a CSD method, and a series capacitance divided voltage comparison method can also be used.

  The touch signal detection unit 37 includes a VDD signal transmission unit 39, SW4, a charge storage capacitor 40, SW5 having a reset switch function, a reference voltage signal transmission unit 41, and a comparator unit.

  The Y electrode and the X electrode are driven alternately. That is, when the Y electrodes SW1 and SW3 are in the connected state, the X electrodes SW1 and SW3 are in the open state. Conversely, when the X electrodes SW1 and SW3 are in the connected state, the Y electrodes SW1 and SW3 are in the open state.

  As shown in the figure, when SW1 and SW3 of the Y electrode are connected, SW4 is connected to the VDD signal transmission unit 39 side, and SW2 and SW5 are open, when the finger 43 approaches the electrode unit 35, A stray capacitance 44 is generated in the electrode part 35, and charges are accumulated in the electrode part 35. Next, the SW 4 is switched to the charge storage capacitor 40 side, and this charge is transferred to the charge storage capacitor 40. The electric charge stored in the electrode unit every clock is stored in the charge storage capacitor 40, and the voltage of the charge storage capacitor 40 increases. When this reaches a certain voltage, SW5 is connected to discharge the charge storage capacitor 40. When touched, the charge stored in the charge storage capacitor 40 increases in one clock, so that the voltage is constant with a smaller number of clocks than in the case of not touching. The touch is recognized by the difference in the number of clocks accumulated at this constant voltage.

  Next, the driving timing of the parallax barrier and the touch panel of this embodiment will be described with reference to FIG. FIG. 8 is a diagram showing drive signals for the X and Y electrodes. As shown in the figure, drive signals are set in the order of the touch panel drive period 28, the high impedance period 27, and the parallax barrier drive period 26 for the Y electrode. On the other hand, in the X electrode, drive signals are set in the order of the high impedance period 27, the touch panel drive period 28, and the parallax barrier drive period 26.

  As described above, when the touch panel is driven, when the Y electrode is in the touch panel drive period, the X electrode is set in the high impedance period, and when the X electrode is in the touch panel drive period, the Y electrode is set in the high impedance period. This signal switching will be described with reference to FIG. When the Y electrode is in the touch panel drive period 28, SW1 and SW3 are connected to the Y electrode. On the other hand, for the X electrode, SW1 and SW3 are in an open state, and the X electrode is in a high impedance state. When the X electrode is in the touch panel drive period 28, SW1 and SW3 are connected to the X electrode. On the other hand, as for the Y electrode, SW1 and SW3 are in an open state, and the Y electrode is in a high impedance state. In the parallax barrier driving period 26, both the X electrode and the Y electrode are in a connected state with SW1 and SW2, and SW3 is in an open state. In this way, the drive signal is switched by switching between SW1, SW2, and SW3.

  In addition, a period in which the touch panel driving period and the high impedance period in the X electrode and the Y electrode are combined is shorter than the barrier liquid crystal driving period. Usually, the liquid crystal has a driving frequency of about 60 Hz to 70 Hz. On the other hand, in the touch panel integrated barrier liquid crystal according to the present embodiment, the touch panel drive period 46 and the high impedance period 27 are set in addition to the parallax barrier drive period 26, and therefore, from the end of the liquid crystal drive period to the start of the next liquid crystal drive period. The liquid crystal must maintain the driving state. Accordingly, in the case of a normal driving frequency, the driving state of the liquid crystal cannot be maintained, the contrast is lowered, and the 3D depth may be deteriorated. Therefore, in this embodiment, by increasing the drive frequency to about 120 Hz, the time for maintaining the liquid crystal drive state is shortened, and the decrease in contrast is prevented.

  The present embodiment is different from the first embodiment in that a display panel other than the LCD, for example, a display panel that does not use a polarizing plate such as a plasma display or an organic EL is used. Since the basic configuration excluding the polarizing plate of the touch panel integrated parallax barrier, the drive circuit configuration, and the drive signal are the same as those in the first embodiment, the description thereof is omitted.

  FIG. 9 is a cross-sectional view illustrating a configuration of a display device including a touch panel integrated parallax barrier according to the present embodiment. A touch panel integrated parallax barrier is pasted on the display panel 49. As the display panel 49, a plasma display, an organic EL, or the like is used, and no polarizing plate is provided on the surface of the panel. In the touch panel integrated parallax barrier, the lower substrate 7 provided with the Y electrode 8 and the upper substrate 1 provided with the X electrode 10 are arranged so that the electrodes face each other, and the liquid crystal layer 9 is provided between the upper and lower substrates. It is done. Here, since the polarizing plate is not used in the display device 49 used in this embodiment, the upper polarizing plate 12 is provided on the upper substrate 1 of the touch panel integrated parallax barrier, and the lower polarizing plate 6 is provided on the lower substrate 7. Provided.

  In each of the embodiments described above, the touch panel integrated parallax barrier and the display panel are bonded to each other with an adhesive, but the bonding method is not limited thereto. The adhesive may be provided on each adherend partially or only on the inner periphery. Moreover, you may use an adhesive sheet instead of an adhesive agent.

  By combining the touch panel and the parallax barrier into one, the thickness and weight are improved, the risk of bonding is reduced, and the cost is reduced by combining the drive circuit. In addition to LCDs, various displays such as plasma displays and organic EL displays are used. It can be applied to various display devices and can provide a touch panel function and a 3D function.

DESCRIPTION OF SYMBOLS 1 Right-eye image 2 Left-eye image 3 Light emitted from left-eye image 4 Light emitted from right-eye image 5 Striped light shielding part 6 Lower polarizing plate 7 Lower substrate 8 Y electrode 9 Liquid crystal layer 10 X electrode 11 Upper substrate 12 Upper polarizing plate 13 Adhesive layer 14 BM
DESCRIPTION OF SYMBOLS 15 Display apparatus 16 Touch panel integrated parallax barrier 17 Display panel 18, 43 Finger 19 Electrostatic coupling of finger and Y electrode 20 Electrostatic coupling of finger and X electrode 21, 35 Electrode part 22 Touch signal detection circuit 23, 37 Touch Signal detection unit 24, 38 Parallax barrier output buffer circuit 25, 36 Parallax barrier output unit 26 Parallax barrier driving period 27 High impedance period 28 Touch panel driving period 30 LCD
31 Substrate 32 Counter substrate 33 Lower polarizing plate for LCD 34 Upper polarizing plate for LCD 39 VDD signal transmission unit 40 Charge storage capacitor 41 Reference voltage signal transmission unit 42 Comparator unit 44 Floating capacitance 45 Display panel

Claims (5)

Liquid crystal is sealed between a substrate in which a plurality of transparent electrodes are provided adjacent to each other with slits, and a substrate in which a plurality of counter electrodes are provided adjacent to each other so as to be orthogonal to the transparent electrodes. A touch panel integrated parallax barrier,
A display panel disposed under the touch panel integrated parallax barrier;
The transparent electrode and the counter electrode are connected to a driving circuit, respectively, and a parallax barrier driving and a touch panel driving are alternately controlled to display a 3D image and detect a touch position. A black matrix is formed on the display panel,
The display device according to claim 1, wherein a slit of the transparent electrode is parallel to and overlaps with the black matrix.   The display device according to claim 1, wherein the driving circuit includes a touch signal detection unit and a parallax barrier driving unit.   The display device according to claim 1, wherein a driving signal having a parallax barrier driving period, a high impedance period, and a touch panel driving period is sent to the transparent electrode and the counter electrode, respectively. .   5. The display device according to claim 4, wherein, in one of the transparent electrode and the counter electrode, when the driving signal is in the touch panel driving period, the other electrode is in a high impedance state.

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