JP5137690B2 - Electro-optical device and electronic apparatus equipped with the same - Google Patents

Description

The present invention may, for example, electrical-optical device, and relates to electronic equipment equipped with this.

  In general, a digital signal is used as an image signal I / F between an electro-optical device such as a display device and an electronic device body. For this reason, a digital image signal input from the outside is converted into an analog potential in the display device. A DAC (Digital Analogue Converter) circuit is required. This DAC circuit is generally configured on a driving IC mounted on an active matrix substrate. Although the DAC circuit may be integrally formed on the active matrix substrate by a semiconductor manufacturing process (for example, Patent Document 1), there are problems such as an increase in the peripheral width (frame) of the display device and an increase in power consumption.

  A DAC circuit is usually a memory circuit that latches a digital signal, a reference potential generation circuit that generates a plurality of analog potentials, or a digital that is latched by a memory circuit, whether it is built in a drive IC or integrally formed on an active matrix substrate. It consists of a selector circuit that selects one analog potential from a plurality of analog circuits according to data, an amplifier circuit that writes the selected analog potential to the data line, etc., and a plurality of resistors arranged in series as a reference potential generation circuit Ladder resistors are commonly used. The relationship between the input digital signal and the output analog potential is determined by the setting of the ladder resistance.

JP 2000-242209 A

  The relationship between the input digital signal and the output analog potential, that is, the ladder resistance, is determined by the type of liquid crystal element used, the thickness of the liquid crystal layer (cell gap), etc., and various settings are required depending on the characteristics of the product. As described above, in order to suppress an increase in the frame and power consumption, the DAC circuit is preferably configured on the driving IC mounted on the active matrix substrate. However, if the ladder resistance is built in the driving IC, the ladder resistance is provided for each product. It is necessary to make the specifications so that the setting of the driver can be changed, resulting in an increase in the size of the driving IC, an increase in cost, an increase in power consumption, and a decrease in accuracy.

Display an electro-optical device according to the present invention, the scan lines and the data lines, a thin film transistor provided corresponding to intersections of scanning lines and data lines, and pixel electrodes provided corresponding to the thin film transistor, is formed on the substrate outside the area of the region, through a data line, a first mounting terminal the analog potential is supplied to be applied to the picture element electrodes, a reference potential to output a plurality of reference potential corresponding to the analog potential and circuitry, insulated first mounting terminal electrically, with the second mounting terminal for outputting the reference potential of criteria potential circuit or al multiple, is formed, and inputs a video signal as a digital signal The driving IC that outputs an analog potential corresponding to the digital signal is mounted at a position at least partially overlapping the reference potential circuit, and the driving IC is connected to the first mounting terminal and the second mounting terminal. The second Implementation receives a reference potential corresponding to the digital signal from the terminal, and outputs a reference potential which is input to the first mounting terminal as an analog potential corresponding to the digital signal.

The analog potential applied to the electro-optical panel based on the use a digital signal such a configuration, the reference voltage circuit formed on the substrate (e.g., a ladder resistance) because it can be defined by the type-liquid crystal layer of the liquid crystal element Even if the thickness of the IC changes, it is not necessary to change the driving ICs one by one by changing the reference potential circuit on the substrate, which is relatively easy to change the design value. The cost of the driving IC can be reduced. In addition, since the reference potential circuit (for example, ladder resistor) can be removed from the drive IC, the size of the drive IC can be reduced, and further cost reduction can be realized. On the other hand, a circuit that performs latching of a digital signal (memory circuit), selection of a reference potential, amplification of driving capability, and the like that constitute a DAC circuit is arranged in a driving IC having a high integration rate. ) And an increase in power consumption can be avoided. Further, since the driver IC at least partially overlaps the reference potential circuit, an increase in the size of the display device can be suppressed even if a reference potential circuit (for example, a ladder resistor) is provided over the glass substrate. Also, since the wiring impedance from the reference potential circuit (for example, ladder resistor) to the driving IC can be minimized, the accuracy of the reference potential is good.

Further, the present invention is to form a plurality of criteria potential circuit on a base plate, each of the criteria potential circuits, a reference potential corresponding to each color of image pixel electrode, or analog potential picture element electrode the reference potential corresponds to each write polarity for writing, proposes that consists electrical-optical device so as to output.

  With this configuration, it is possible to cope with a driving method such as a liquid crystal mode in which the potential-transmittance characteristics are different for each color wavelength, or a dot inversion driving with a fast switching speed of the writing polarity.

Further, the present invention is that the reference potential circuit of multiple, for each color, or the third mounting pin for each polarity inclusive can write a switching switch for switching a control signal for controlling the selector switch is supplied And an electro-optical device in which a driving IC is connected to a third mounting terminal and outputs a control signal .

  With this configuration, the number of mounting terminals can be reduced even when a plurality of reference potential circuits are provided on the substrate. Therefore, the frame can be enlarged to prevent the electro-optical panel from being enlarged, and the mounting yield can be improved. Therefore, the cost can be suppressed.

Further , since the changeover switch can be controlled from the drive IC, an extra circuit configuration is not required, the frame is enlarged, the enlargement of the size of the electro-optical panel can be prevented, and the mounting yield is also improved, thereby suppressing the cost. be able to.

The present invention also proposes an electronic apparatus provided with the above electro-optical device. These electronic devices have display performance that is optimally set according to the application, have high display quality, and can be manufactured at low cost while suppressing manufacturing costs.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a perspective configuration diagram (partially sectional view) of a liquid crystal display device 910 according to the present embodiment. The liquid crystal display device 910 includes an active matrix substrate 101 as a substrate and a counter substrate 912 that are bonded to each other with a sealant 923 at a predetermined interval, and a nematic phase liquid crystal material 922 as an electro-optical material. Although not shown, an alignment material made of polyimide or the like is applied onto the active matrix substrate 101 and rubbed to form an alignment film. The counter substrate 912 includes a color filter corresponding to a pixel (not shown), a black matrix made of a low reflection / low transmittance resin for preventing light leakage and improving contrast, and a counter on the active matrix substrate 101. A transparent counter electrode 930 that is short-circuited with the conducting portion 330 is formed. An alignment material made of polyimide or the like is applied to the surface in contact with the nematic phase liquid crystal material 922, and is rubbed in a direction orthogonal to the alignment film rubbing treatment direction of the active matrix substrate 101.

  Further, an upper polarizing plate 924 is disposed outside the counter substrate 912, and a lower polarizing plate 925 is disposed outside the active matrix substrate 101, so that the polarization directions thereof are orthogonal to each other (crossed Nicols). Further, a backlight unit 926 and a light guide plate 927 are disposed below the lower polarizing plate 925, and light is emitted from the backlight unit 926 toward the light guide plate 927. The light guide plate 927 activates light from the backlight unit 926. It functions as a light source of the liquid crystal display device 910 by reflecting and refracting light so that it becomes a vertical and uniform surface light source toward the matrix substrate 101. The backlight unit 926 is an LED unit in this embodiment, but may be a cold cathode fluorescent lamp (CCFL). The backlight unit 926 is connected to an external power supply circuit 784 (not shown in FIG. 1) of the electronic device main body through the connector 929, and is supplied with power.

  Although not shown, if necessary, the periphery of the liquid crystal display device 910 may be covered with an outer shell, or a protective glass or acrylic plate may be attached on the upper polarizing plate 924, An optical compensation film may be attached to improve the angle. Further, a prism sheet for improving luminance uniformity or an optical sheet for improving luminance may be disposed between the light guide plate 927 and the lower polarizing plate 925.

  Further, the active matrix substrate 101 is provided with a projecting portion 110 that projects outward from the counter substrate 912, and an FPC (flexible substrate) 928 and a driving IC 921 are provided on the projecting portion 110 via an ACF (Anisotropic Conductive Film). Mounted and electrically connected. An FPC (flexible substrate) 928 is connected to the main body of the electronic device, and if necessary, signals and power are supplied from an external power supply circuit 784 and a video processing circuit 780 (both not shown in FIG. 1) to drive an IC 921 and an active matrix substrate. 101.

  FIG. 2 is a block diagram of the active matrix substrate 101. On the active matrix substrate 101, 480 scanning lines 201 (201-1 to 201-480) and 1920 data lines 202 (202-1 to 202-1920) are formed orthogonally, and 480 lines are formed. The capacitor lines 203 (203-1 to 203-480) are arranged in parallel with the scanning lines 201-1 to 201-480. The capacitor lines 203-1 to 203-480 are short-circuited to each other and connected to the common potential wiring 335, and further connected to the opposing conductive portion 330. The common potential wiring 335 is drawn to the dotted line frame A portion of the overhang portion 110 and is given a common potential (COM) from the drive IC 921. In this embodiment, so-called common potential inversion driving is used, so that the common potential (COM) becomes an inversion signal that is inverted for a certain period. The scanning lines 201-1 to 201-480 are connected to the scanning line driving circuit 301, and the data lines 202-1 to 202-1920 are connected to the data line driving circuit 302 and are driven appropriately.

  The scanning line driving circuit 301 and the data line driving circuit 302 are formed by using a so-called system-on-glass (SOG) technique in which polysilicon thin film transistors are integrated on the active matrix substrate 101, and a pixel switching element 401 described later. This is a so-called drive circuit built-in type liquid crystal display device manufactured in the same process as −nm. In the scanning line driving circuit 301 and the data line driving circuit 302, signal wirings necessary for the driving are drawn out to the dotted line frame A portion of the projecting portion 110. A broken line frame B in the dotted line frame A part of the overhanging portion 110 is an area where the drive IC 921 is mounted, and a broken line frame C similarly indicates an area where an FPC (flexible substrate) 928 is mounted. A detailed configuration in the dotted line frame A part will be described later.

  FIG. 3 is a circuit diagram in the vicinity of the intersection of the mth data line 202-m and the nth scanning line 201-n in the display area 310. A pixel switching element 401-nm including an n-channel field effect polysilicon thin film transistor is formed at each intersection of the scanning line 201-n and the data line 202-m, and its gate electrode is connected to the scanning line 201-n. The source / drain electrodes are connected to the data line 202-m and the pixel electrode 402-nm, respectively. The pixel electrode 402-nm and the electrode short-circuited to the same potential form a capacitance line 203-n and an auxiliary capacitance capacitor 403-nm, and a nematic phase liquid crystal material 922 when assembled as a liquid crystal display device. After that, a capacitor is formed with the counter electrode 930 as well.

  FIG. 4 is a block diagram showing a specific configuration of the electronic apparatus in this embodiment. The liquid crystal display device 910 is the liquid crystal display device described in FIG. 1, and the external power supply circuit 784 and the video processing circuit 780 send necessary signals and power to the liquid crystal display device 910 through an FPC (flexible substrate) 928 and a connector 929. Supply. The central processing circuit 781 acquires input data from the input / output device 783 via the external I / F circuit 782. Here, the input / output device 783 is, for example, a keyboard, a mouse, a trackball, an LED, a speaker, an antenna, or the like. The central processing circuit 781 performs various arithmetic processing based on data from the outside, and transfers the result to the video processing circuit 780 or the external I / F circuit 782 as a command. The video processing circuit 780 updates the video information based on the command from the central processing circuit 781 and changes the signal to the liquid crystal display device 910, whereby the display video of the liquid crystal display device 910 changes. In this embodiment, the video signal sent from the video processing circuit 780 to the liquid crystal display device 910 is a so-called digital RGB signal, and each pixel information is transmitted as a RGB 6-bit digital signal. Here, the electronic device 1000 specifically includes a monitor, a TV, a notebook computer, a PDA, a digital camera, a video camera, a mobile phone, a mobile photo viewer, a mobile video player, a mobile DVD player, a mobile audio player, and the like.

  FIG. 5 is an enlarged view of a dotted line frame A portion in the overhang portion 110 described in FIG. A broken line frame B indicates a region where the driving IC 921 is mounted. A plurality of mounting terminals 501A are arranged in the broken line frame B, and the mounting terminal 501A is necessary for driving the scanning line driving circuit 301. A power supply and a signal (for example, a clock signal, a start pulse signal, an enable signal, and the like) are supplied from the driving IC 921. Similarly, a plurality of mounting terminals 501B are arranged, and power and signals (for example, video video signals (analog potential corresponding to digital signals), enable signals, etc.) necessary for driving the data line driving circuit 302 are mounted on the mounting terminals 501B. Is supplied from the driving IC 921. In addition, a mounting terminal 501C is provided, and a common potential (COM) is supplied to the common potential wiring 335 from the driving IC 921 to the mounting terminal 501C.

  Further, a plurality of OLB (Outer Lead Bonding) terminals 504 are connected to an FPC (flexible substrate) 928, and power supply potentials or signals from the video processing circuit 780 and the external power supply circuit 784 are connected to the OLB terminals 504 via the FPC 928. Entered. The plurality of OLB terminals 504 are respectively connected to the plurality of mounting terminals 503, and the driving IC 921 is mounted on the mounting terminals 503. In this manner, the power supply potential or signal from the video processing circuit 780 or the external power supply circuit 784 is input to the drive IC 921.

  Further, a first ladder resistor 511, a second ladder resistor 512, and a third ladder resistor 513 are arranged in the broken line frame B.

  The first ladder resistor 511 includes 66 mounting terminals 521-1 to 521-66, and these mounting terminals 521-1 to 521-66 are all connected to connection terminals provided on the drive IC 921 side. The mounting terminals 521-n and 521-n + 1 are electrically connected by resistors 522 (522-1 to 522-65). A resistor 522-n (n = 1 to 65) is a resistor element formed to have a desired resistance value by appropriately adjusting the width and length of a metal wiring (for example, molybdenum). n (n = 1 to 65) are not necessarily the same resistance value (that is, they have different widths and lengths). The driving IC 921 applies a constant voltage controlled to a constant voltage to the mounting terminals 521-1 and 521-66. In this embodiment, the mounting terminal 521-1 is 0V and the mounting terminal 521-66 is + 5V at a certain timing. When the voltage is applied in this way, a voltage determined by the resistance division of the resistors 522-n (n = 1 to 65) is applied to the mounting terminals 521-2 to 521-65. For example, the resistor 522-1 and the resistor 522-65 are 150Ω, the resistor 522-2 and the resistor 522-64 are 35Ω, the resistor 522-3 and the resistor 522-63 are 20Ω, and the resistor 522-4 to the resistor 522-62 are If it is 10Ω, 0.15V is applied to the mounting terminal 521-2, 0.185V is applied to the mounting terminal 521-3, 0.205V is applied to the mounting terminal 521-4, and the mounting terminal 521 is applied. 4.85 V is applied to -65.

  The drive IC 921 includes an analog circuit that converts a 6-bit digital signal into an analog potential of the mounting terminals 521-2 to 521-65 using the potential of the mounting terminals 521-2 to 521-65 as a reference potential. That is, if the 6-bit digital signal is “000000”, the potential of the mounting terminal 521-2 (0.15V in the above example) is selected as the output potential, and the current is amplified and output by the amplifier. If so, the potential of the mounting terminal 521-65 (4.85V in the above example) is selected as the output potential, and this potential is amplified by an amplifier and output. In addition, since driving for reversing the writing polarity is performed in order to ensure the reliability of the liquid crystal element, the potential applied to the mounting terminal 521-1 and the mounting terminal 521-66 is reversed once every fixed time. In this embodiment, the potential applied to the mounting terminal 521-1 and the mounting terminal 521-66 is switched every 34.6 microseconds. That is, the potential is applied so that the mounting terminal 521-1 becomes + 5V and the mounting terminal 521-66 becomes 0V in 34.6 microseconds from the previous state. In this way, 1H inversion driving in which the polarity of the output potential for the same video signal is inverted every 1H (horizontal selection period) can be realized.

  Alternatively, as another configuration example, the number of ladder resistors on the substrate may be doubled, and the potential of one of the two ladder resistors may be used according to the writing polarity. Such a configuration is an effective means when the switching period of the writing polarity is short as in the case of dot inversion driving, but has a demerit that the power consumption increases as the ladder resistance increases.

  In this manner, the 6-bit digital signal sent from the video processing circuit 780 to the liquid crystal display device 910 is converted into an appropriate analog potential as a video signal by the driving IC 921 and is applied to a plurality of mounting terminals 501B on the active matrix substrate 101. Is output to the pixel electrode 402-nm through the data lines 202-1 to 202-1920 at an appropriate timing via the data line driving circuit 302, and the nematic phase liquid crystal material 922 is connected to the counter electrode 930. An electric field due to a potential difference is applied, the orientation state changes, and the transmittance changes, whereby display by a video signal is performed.

  Since the second ladder resistor 512 and the third ladder resistor 513 have exactly the same configuration as the first ladder resistor 511 except that the resistance values of the first ladder resistor 511 and the respective resistance elements are different, the description of the configuration is omitted. To do. Similarly to the first ladder resistor, 64 analog potentials are input to the drive IC 921 from the second ladder resistor 512 and the third ladder resistor 513. In this embodiment, the first ladder resistor 511 is used for analog potential conversion of a digital signal applied to the pixel electrode 402-nm corresponding to red (R), and the pixel electrode 402-n- corresponding to green (G). The second ladder resistor 512 is used for converting the analog potential of the digital signal applied to m, and the third ladder resistor is used for converting the analog potential of the digital signal applied to the pixel electrode 402-nm corresponding to blue (B). 513 are used correspondingly. That is, since the relationship between the digital signal and the analog potential can be defined for each RGB color, even when using a liquid crystal element in which the relationship between the voltage applied to the liquid crystal and the transmittance varies depending on the wavelength of light, the resistance value of each resistive element By appropriately changing the color for each color, it can be handled. Note that in the case of using a liquid crystal element that does not have such a problem, the second ladder resistor 512 and the third ladder resistor 513 may be omitted.

  The relationship between the potential applied to the nematic phase liquid crystal material 922 and the transmittance varies depending on the selection of the liquid crystal material and the setting of the thickness (gap). These parameters change depending on the reliability, response speed, and viewing angle, so it is necessary to change them depending on the application. For example, the electronic device 1000 for displaying moving images uses a liquid crystal material that has a transmittance of almost 0 (black) when a relatively large potential difference is applied in order to increase the response speed. Since power consumption becomes important, the response speed is sacrificed to some extent, and a liquid crystal material that becomes black with a smaller potential difference is used. Therefore, conventionally, in order to keep the relationship between the digital signal sent from the video processing circuit 780 and the transmittance (or reflectance) appropriately, the drive IC 921 is prepared by changing the design for each application, or on the drive IC 921 side. Although it is necessary to have a plurality of ladder resistors, there is a problem that the cost of the driving IC 921 is increased or the size is increased. In this embodiment, such a problem is caused by forming the ladder resistors on the active matrix substrate 101. Does not occur. In addition, since the first ladder resistor 511, the second ladder resistor 512, and the third ladder resistor 513 are disposed in the region (dashed frame B) where the drive IC 921 is mounted, the active matrix is provided by providing the ladder resistor. There is no increase in the size of the substrate 101, and there is little deterioration of the transient response characteristics due to the impedance of the routing wiring, and the accuracy is high even when used at a high frequency.

  As described above, based on this embodiment, a driving IC can be shared among a plurality of types of display devices with different applications, and the size of the driving IC can be reduced, so that the cost is reduced, and a display device with a small size is additionally provided. realizable. In addition, the display has high gradation accuracy and is excellent in image quality. When such a display device is mounted on the electronic device 1000, the electronic device 1000 having a small-sized outer shape, low cost, and a high-quality display can be realized.

[Second Embodiment]
FIG. 6 is an enlarged view of a dotted line frame A portion of the projecting portion 110 of FIG. 2 instead of FIG. 5 described in the first embodiment. Since the active matrix substrate in this embodiment has the same configuration as that of the active matrix substrate 101 described in the first embodiment except for the configuration in the dotted line frame A part, the other description is omitted. Further, the embodiments of the liquid crystal display device 910 and the electronic apparatus 1000 are not different from those of the first embodiment except for the contents described in FIG. In FIG. 6, the broken line frame B, the plurality of mounting terminals 501A, the plurality of mounting terminals 501B, the mounting terminals 501C, the plurality of OLB terminals 504, and the plurality of mounting terminals 503 are the configurations described in the first embodiment with reference to FIG. Since there is no difference between them, the same number is assigned and the description is omitted.

  In the present embodiment, a ladder resistor 514 with a switching function is arranged instead of the first ladder resistor 511, the second ladder resistor 512, and the third ladder resistor 513 described in FIG. 5 of the first embodiment. The ladder resistor 514 with a switching function includes a fourth ladder resistor 514A, a fifth ladder resistor 514B, 66 mounting terminals 531-1 to 531-66, and 66 first changeover switches 534 (534-1 to 534). -66) and 66 second changeover switches 535 (5355-1 to 535-66). The fourth ladder resistor 514A is configured by connecting 65 first resistor elements 532 (532-1 to 532-65) in series, and the fifth ladder resistor 514B is composed of 65 second resistor elements. 533 (533-1 to 533-65) are connected in series. Each of the first resistance elements 532-1 to 532-65 and the second resistance elements 533-1 to 533-65 has a desired resistance value by appropriately adjusting the width and length of the metal wiring (for example, molybdenum). The resistance elements are formed so as to have the same resistance value (that is, have different widths and lengths).

  One end of the nth first changeover switch 534-n and one end of the nth second changeover switch 535-n are connected to the nth mounting terminal 531-n (n = 1 to 66). The other end of the nth first changeover switch 534-n (n = 1 to 65) is connected to one end of the nth first resistance element 532-n, and the nth first resistance element 532-n. Is connected to the (n + 1) th first changeover switch 534-n + 1. The other end of the nth second changeover switch 535-n (n = 1 to 65) is connected to one end of the nth second resistance element 533-n, and the nth second resistance element 533-n. Is connected to the (n + 1) th second changeover switch 535-n + 1.

  Here, each of the first changeover switches 534-1 to 534-66 and the second changeover switches 535-1 to 535-66 is a CMOS type transmission gate, and includes one n-channel thin film transistor and one p-channel thin film transistor. Are connected in parallel. Here, the gate electrode of the n-channel type thin film transistor is a positive control signal terminal, and the gate electrode of the p-channel type thin film transistor is a negative control signal terminal. To do.

  The positive control signal terminals of the first selector switches 534-1 to 534-66 and the negative control signal terminals of the second selector switches 535-1 to 535-66 are connected to the mounting terminal 515, and the first selector switch Negative control signal terminals of 534-1 to 534-66 and positive control signal terminals of the second changeover switches 535-1 to 535-66 are connected to the mounting terminal 516. The mounting terminal 515 and the mounting terminal 516 are connected to a connection terminal on the driving IC 921 side, and a control potential is applied as a control signal from the driving IC 921 to the mounting terminal 515 and the mounting terminal 516. With this configuration, when the high potential (+5 V in this embodiment) is applied to the mounting terminal 515 and the low potential (0 V in this embodiment) is applied to the mounting terminal 516, the first changeover switches 534-1 to 534-66 are all turned on. The second changeover switches 535-1 to 535-66 are all turned OFF. Therefore, the n-th mounting terminal 531-n (n = 1 to 65) and the mounting terminal 531-n + 1 are the first resistance element 532-n, the first changeover switch 534-n, and the first changeover switch 534-n + 1. It will be connected across the ON resistance. On the other hand, when a low potential (= 0V) is applied to the mounting terminal 515 and a high potential (= 5V) is applied to the mounting terminal 516, all the first changeover switches 534-1 to 534-66 are turned off, and the second changeover switch 535- 1 to 535-66 are all turned OFF. Therefore, the n-th mounting terminal 531-n (n = 1 to 65) and the mounting terminal 531-n + 1 are the second resistance element 533-n, the second change-over switch 535-n, and the second change-over switch 535-n + 1. It will be connected across the ON resistance. In other words, the resistance between the mounting terminals 531-1 to 531-66 can be switched to two systems, that is, the series of the fourth ladder resistor 514A and the series of the fifth ladder resistor 514B. . Here, the transistors constituting the first changeover switches 534-1 to 534-66 and the second changeover switches 535-1 to 535-66 are the transistors constituting the scanning line driving circuit 301 and the data line driving circuit 302 and pixel switching. Since it is manufactured in the same process as the element 401-nm, the cost does not increase.

  In this embodiment, a constant potential of 0 V is always applied to the mounting terminal 531-1 and a constant potential of 5 V is applied to the mounting terminal 531-66. As a result, a desired analog potential is applied to the mounting terminals 531-2 to 531-65 by resistance division in the same manner as the mounting terminals 521-2 to 521-65 described in the first embodiment. Since the drive IC 921 converts the digital signal into an analog potential and outputs the analog signal using the, the description is omitted. In this embodiment mode, the analog potential applied to the mounting terminals 531-2 to 531-65 changes into two types depending on the potential level applied to the mounting terminal 515 and the mounting terminal 516. Note that in this embodiment mode, the potential applied to the mounting terminal 531-1 and the mounting terminal 531-66 is constant and is not inverted. On the other hand, the mounting terminal 515 and the mounting terminal 516 are reversely driven between 0 V / 5 V potentials while maintaining the opposite polarities of the potentials applied every 34.6 microseconds. In this way, 1H inversion driving in which the polarity of the output potential for the same video signal is inverted every 1H (horizontal selection period) can be realized.

  As described above, in this embodiment, a plurality of ladder resistors are provided, but the number of mounting terminals can be reduced by incorporating a changeover switch for switching between them in the active matrix substrate. For this reason, the size of the driving IC 921 is not increased by the mounting terminal pad. In addition, since no current flows through the ladder resistor system that is not used, current consumption can be reduced. Since the changeover switch is arranged in the mounting area of the drive IC 921, the size of the liquid crystal display device 910 does not increase.

  In this embodiment, the configuration has two systems of ladder resistance for positive and negative polarity of inversion drive. However, as in the first embodiment, it has three systems of ladder resistance corresponding to each color of RGB, and these are temporally connected. It is good also as a structure which has 6 ladder resistances, and it is good also as a structure switched according to each RGB color and positive / negative polarity. Furthermore, it is good also as a structure which has four ladder resistances corresponding to four or more colors, such as RGBW (red, green, blue, white).

  The present invention is not limited to the embodiments, and is used for liquid crystal display devices such as a vertical alignment mode (VA mode) instead of the TN mode, an IPS mode using a lateral electric field, and an FFS mode using a fringe electric field. It may also be used for a display device (OLED) using organic EL. Further, not only a display device but also an image sensor using an active matrix substrate may be used.

  Further, an amorphous silicon thin film transistor may be used as an active element instead of a polycrystalline polysilicon thin film transistor, and the data line driving circuit and the scanning line driving circuit may be configured on the driving IC side instead of on the glass substrate.

The perspective view of the liquid crystal display device 910 regarding the Example of this invention. The block diagram of the active matrix substrate 101 regarding the Example of this invention. The pixel circuit diagram of the active matrix substrate 101 regarding the Example of this invention. The block diagram which shows the Example of the electronic device 1000 of this invention. The enlarged view of the dotted-line frame A part of FIG. 2 regarding the Example of this invention. The enlarged view of the dotted-line frame A part of FIG. 2 regarding another Example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Active matrix board | substrate as a board | substrate, 110 ... Overhang | projection part, 201 ... Scanning line, 202 ... Data line, 203 ... Capacitance line, 301 ... Scanning line drive circuit, 302 ... Data line drive circuit, 401 ... Pixel switching element, 402 ... Pixel electrode, 501A, 501B, 501C, 503 ... Mounting terminal, 504 ... OLB terminal, 511 ... First ladder resistor, 512 ... Second ladder resistor, 513 ... Third ladder resistor, 514 ... Ladder with switching function Resistance, 514A ... fourth ladder resistance, 514B ... fifth ladder resistance, 521, 531 ... mounting terminal, 522 ... resistance, 532 ... first resistance element, 533 ... second resistance element, 534 ... first Changeover switch, 535... Second changeover switch, 910... Liquid crystal display device, 921.

Claims (6)

A substrate in a region outside a display region in which a scanning line and a data line, a thin film transistor provided corresponding to the intersection of the scanning line and the data line, and a pixel electrode provided corresponding to the thin film transistor are formed above,
A first mounting terminal to which an analog potential applied to the pixel electrode is supplied via the data line ;
A reference potential circuit that outputs a plurality of reference potentials corresponding to the analog potential;
A second mounting terminal that is insulated from the first mounting terminal and outputs the plurality of reference potentials from the reference potential circuit;
Is formed,
A driving IC that inputs a video signal as a digital signal and outputs an analog potential corresponding to the digital signal is mounted at a position at least partially overlapping the reference potential circuit,
The driving IC is connected to the first mounting terminal and the second mounting terminal, receives a reference potential corresponding to the digital signal from the second mounting terminal, and uses the input reference potential as the digital signal. Outputting an analog potential corresponding to the signal to the first mounting terminal;
Electro-optic device. The reference potential circuit is
A plurality of resistive elements each formed to have a predetermined resistance value are connected in series,
Each of the resistance elements electrically connects terminals of the plurality of second mounting terminals provided corresponding to the plurality of reference potentials.
The electro-optical device according to claim 1. A plurality of the reference potential circuits are formed on the substrate, and each of the reference potential circuits has a reference potential corresponding to each color of the pixel electrode or a writing polarity when writing the analog potential to the pixel electrode. The electro-optical device according to claim 1, wherein the electro-optical device is configured to output a reference potential corresponding to. A selector switch for switching the plurality of reference potential circuits for each color or for each writing polarity;
A third mounting terminal to which a control signal for controlling the changeover switch is supplied;
Is formed on the substrate,
The driving IC is connected to the third mounting terminal and outputs the control signal.
The electro-optical device according to claim 3. The reference potential circuit is
A mounting region of a flexible substrate connected to an external device on a projecting portion provided by projecting one substrate out of a pair of substrates opposed to each other with an electro-optic material sandwiched therebetween; Formed between the display area and
The electro-optical device according to claim 1. An electronic apparatus comprising the electro-optical device according to any one of claims 1 to 5.

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