JP2004118215A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a driver from malfunctioning due to a peripheral sealing material in an LCD with the built-in driver. <P>SOLUTION: Although a sealing material 3 passes above a drain driver consisting of a horizontal shift register 61 and a sampling part 62, the edge line of the sealing material 3 is made straight in the area on the horizontal shift register 61. Operation characteristics of TFT elements just below the sealing material 3 varies and are different from those of TFT elements outside the area of the sealing material 3, however the operation characteristics do not differ between phases, and adverse effects for display can be prevented. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a display device using an optical member such as a liquid crystal, and particularly to a display device having a built-in drive circuit.

A set of substrates on which predetermined electrode wirings are formed is attached with a small gap, and a liquid crystal is sealed in the small gap, so that a liquid crystal display device (LCD) comprising a capacitor having a liquid crystal as a dielectric layer as a display pixel. ) Or an organic EL display device using organic electroluminescence (EL), whose light emission amount can be controlled by the amount of current, is widely used as a display in the field of OA equipment and AV equipment because of its advantages of small size, thinness, and low power consumption. Used. In particular, in an LCD, an active matrix type in which a thin film transistor (TFT) is connected as a switching element to control writing and holding of a display signal voltage in each display pixel capacitor can perform high-definition display. Has become.

FIG. 11 is a plan view showing the entire LCD. (1) is a TFT substrate located on the other side of the paper, (2) is a counter substrate located on the near side of the paper, (3) is a peripheral sealing material for bonding the substrate (1) and the substrate (2), and is an epoxy resin. It is made of a thermosetting adhesive such as a resin, a resin that is cured by irradiation with UV light, or the like. Between the TFT substrate (1) and the opposing substrate (2), there is a slit supported by a spacer (not shown), and the sealing material (3) is partially cut out so as to have an injection hole (31). It has become. Liquid crystal is injected into the internal gap from the injection hole (31), and the liquid crystal is sealed by closing the injection hole (31) with a sealing material (32).

The TFT substrate (1) is formed by forming a TFT using polycrystalline silicon (p-Si) as a channel layer on a substrate. On the substrate (1), a plurality of gate lines (GL) and drain lines (DL) are arranged so as to intersect, and at these intersections, a pixel TFT (SE) and a display pixel connected to the pixel TFT (SE) are provided. A display region (4) in which a pixel electrode (PX) forming one of the capacitors is formed, and a gate around the display region (4) mainly composed of a bidirectional shift register and supplying a scanning signal to a pixel TFT (SE). A driver (5), a drain driver (6) mainly comprising a bidirectional shift register and an analog switch and supplying a display signal voltage to the pixel TFT (SE) in synchronization with the scanning of the gate driver (5); A control circuit (7) for switching the shift direction of the register to switch the operation direction of each driver (5, 6) is formed. These drivers (5, 6) are composed of p-Si TFTs having the same structure as that of the display area (4). However, since the operation speed of the p-Si TFT is sufficiently high, if only the pixel TFT (SE) is used in this way, Alternatively, a peripheral driver for driving the driver can be configured, and a driver-incorporated LCD in which the driver is formed in a display panel is possible. These TFTs are covered with a flattening insulating film such as acrylic resin, SOG (SPIN ON GLASS), BPSG (BORO-PHOSPHO SILICATE GLASS), and in the display area (4), the pixel electrode (PX) is overlaid. And is connected to the pixel TFT (SE) via a contact hole formed in the planarization insulating film. (8) is a signal input terminal of these drivers.

(4) The common electrode (9), which is the other of the display pixel capacitors, is entirely formed on the counter substrate (2) in correspondence with the display area (4). The display pixel capacitance is configured such that liquid crystal and a common electrode (9) are partitioned into pixel electrodes. A part of the common electrode (9) is drawn out to a corner of the substrate (2) to serve as a second counter electrode connection terminal (91). Further, a counter electrode signal input terminal (91) for the common electrode (9) is provided on the TFT substrate (1), and is formed in a region corresponding to the counter electrode connection terminal (91) by a lead wire (82). The first counter electrode connection terminal (83) is routed to the first counter electrode connection terminal (83), and the first and second counter electrode connection terminals (91, 83) are connected by a conductive adhesive (92).

FIG. 12 is a partially enlarged plan view of the LCD. The gate driver (5) includes a vertical shift register (51) and a buffer unit (52) provided along the vertical side of the figure. The drain driver (6) includes a horizontal shift register (61) provided along the horizontal side of the figure and a sampling unit (62) including an analog switch corresponding to each column. The analog switch is turned on / off by each output stage of the horizontal shift register (61), and synchronizes with a dot period assigned to each column in each horizontal period, and outputs a display signal from an externally supplied original image signal. The voltage is sampled and output to each column.
JP-A-8-220560

The epoxy resin or the UV resin serving as the sealing material (3) may contain moisture remaining after drying at the time of application, moisture in the outside air, impurity ions, and the like. Polarization is generated in the flattened insulating film, which causes a back channel effect of the TFT under the flattened insulating film to change the threshold value. For this reason, as shown in FIG. 11, in a configuration in which the sealing material (3) passes over the area of the gate driver (5) or the drain driver (6), in particular, a logic circuit such as a shift register uses the sealing material (3). 3) If the operating characteristics of each of the TFT elements change immediately below, a problem of a malfunction and a further malfunction is caused.

Further, even if the change in the characteristics of the TFT element is slight, as shown in FIG. 12, the sealing material (3) has a shape in which the curved portion, particularly the outer edge line, is on the drain driver (6). If there is, in each output stage of the drain driver (6), there is a difference in operation between the one under the sealing material (3) and the other. As a result, the display characteristics are different between the row of the display area (4) corresponding to the output stage below the seal material (3) and the row in the area other than the seal material (3). Similarly, on the gate driver (5) side, display characteristics are different between a row in which the corresponding step of the gate driver (5) is directly below the sealing material (3) and a row in a region other than the sealing material (3). In the figure, the shaded area is where the corresponding step of the gate driver (5) or the drain driver (6) is in the area other than the sealing material (3), and the area without shade is the corresponding step. It is directly below the sealing material (3). The region with the shadow is a region where there is no change in the display characteristics, and the region without the shadow is a region where there is a change in the display characteristics. Looks different from the area. In addition, since a large force is applied to the curved outer edge of the sealing material (3) and affects the characteristics of the TFT element thereunder, the corresponding step of the driver (5, 6) has the sealing material (3). The region in the curved portion of ()) looks different from other regions. As described above, when areas having different display characteristics are mixed in the display area (4), display quality is reduced.

If the control circuit (7) malfunctions, it is not possible to switch the operation direction of the drivers (5, 6), and there is a problem that the versatility of the LCD incorporating the driver is reduced.

The present invention has been made to solve the above-mentioned problem, and has a display in which a pixel electrode group arranged in a matrix and a first thin film transistor group for supplying a display signal voltage to each pixel electrode are formed on an opposing surface. A first region including a plurality of driving circuit regions each including a region, a second thin film transistor group formed around the display region for driving the first thin film transistor, and a control circuit region for controlling the driving circuit; And a second substrate on which a common electrode is formed and a second substrate on which a common electrode is formed, and the optical member is sandwiched by an adhesive provided on a peripheral edge of the display device. Is formed in a straight line extending in the long side direction of the drive circuit region.

(4) This prevents the adhesive from being affected differently between the stages in the drive circuit, and prevents the display regions from being mixed in different display regions.

Particularly, the adhesive is configured to avoid the control circuit area.

(4) Thereby, the operation direction of the drive circuit can be favorably switched.

A display region on which a pixel electrode group arranged in a matrix and a first thin film transistor group for supplying a display signal voltage to each pixel electrode are formed on a facing surface; a second region formed around the display region; A first substrate including a plurality of thin film transistor groups and provided with a plurality of drive circuit regions for driving the first thin film transistor, and a second substrate on which a common electrode is formed are optically bonded by an adhesive provided on a peripheral edge. In a display device in which a member is interposed therebetween, the adhesive is provided such that an edge line of the adhesive on the drive circuit region is provided in a linear shape extending in a long side direction of the drive circuit region. Configuration.

(4) This prevents the adhesive from being affected differently between the stages in the drive circuit, and prevents the display regions from being mixed in different display regions.

A display region on which a pixel electrode group arranged in a matrix and a first thin film transistor group for supplying a display signal voltage to each pixel electrode are formed on a facing surface; a second region formed around the display region; A first substrate including a plurality of thin film transistor groups and provided with a plurality of drive circuit regions for driving the first thin film transistor, and a second substrate on which a common electrode is formed are optically bonded by an adhesive provided on a peripheral edge. In a display device in which members are attached to each other with the members interposed therebetween, the adhesive is provided so as to avoid over the drive circuit region.

(4) This prevents the shift register from being malfunctioned due to the influence of the adhesive.

A display region on which a pixel electrode group arranged in a matrix and a first thin film transistor group for supplying a display signal voltage to each pixel electrode are formed on a facing surface; a second region formed around the display region; A first substrate provided with a plurality of drive circuit regions for driving the first thin film transistor and a control circuit region for controlling the drive circuit; and a second substrate on which a common electrode is formed. In a display device in which a substrate and an optical member are sandwiched by an adhesive provided on a peripheral edge thereof, the adhesive is provided so as to avoid over the drive circuit area and / or the control circuit area. Configuration.

(4) This prevents the shift register and the control circuit from malfunctioning due to the influence of the adhesive.

In particular, the drive circuit includes at least a shift register and a drive signal output unit based on an output from each output stage of the shift register, and the adhesive avoids the shift register area and / or the control circuit area. This is the configuration provided.

(4) This prevents the shift register and the control circuit from malfunctioning due to the influence of the adhesive.

Further, on a facing surface, a display region in which a pixel electrode group arranged in a matrix and a first thin film transistor group for supplying a display signal voltage to each pixel electrode are formed, and a second region formed around the display region is formed. A first substrate provided with a plurality of drive circuit regions for driving the first thin film transistor and a control circuit region for controlling the drive circuit; and a second substrate on which a common electrode is formed. In a display device in which a substrate and an optical member are sandwiched by an adhesive provided on a peripheral edge of the display device, the drive circuit outputs at least a shift register and a drive signal output based on an output from each output stage of the shift register. And the adhesive covers the entire shift register area or the drive signal output area.

(4) With this, the influence of the adhesive on all the steps in the shift register becomes equal, and the operation characteristics of all the steps become uniform, so that the display areas are prevented from being mixed in different display areas.

Particularly, the adhesive is configured to cover the entire drive circuit area.

(4) With this, the influence of the adhesive material on all the stages in the drive circuit becomes equal, and the operating characteristics of all the stages become uniform, so that the display regions are prevented from being mixed in different display regions.

According to the present invention, in a display device having a built-in drive circuit, an adhesive for bonding a pair of electrode substrates facing each other can prevent the drive circuit from malfunctioning, and can perform favorable display. It became so.

FIG. 1 is a partial plan view of the liquid crystal display device according to the first embodiment of the present invention. (1) and (2) are a TFT substrate on which a p-Si TFT is formed and a counter substrate, whose edges are coincident in a plane. In the TFT substrate (1), a plurality of gate lines (GL) and drain lines (DL) are arranged so as to intersect with each other. It has a display area (4) in which pixel electrodes (PX) forming one of the capacitors are arranged in a matrix. In the vicinity of the display area (4), a gate driver including a bidirectional vertical shift register (51) and a buffer section (52) as an output section thereof, and a bidirectional horizontal shift register (61) are provided. A drain driver including a sampling unit (52), which is an output unit controlled by the control unit, is provided. Further, a control circuit (7) is provided around the display area (4) to switch the shift direction of the shift registers (51, 61) to switch the operation direction of the driver between forward and reverse. A common electrode (not shown) is provided on the counter substrate (2).

FIG. 2 is an equivalent circuit diagram of the gate driver units (51, 52). The lower stage is a vertical shift register (51) unit, and the upper stage is an output buffer unit (52). Each stage of the vertical shift register (51) includes a first clocked inverter (53), an inverter (54), and a second clocked inverter (55) connected in parallel to the inverter (54) in the reverse direction. The outputs from the adjacent stages are ANDed by the AND gate (56) and output. The stage output from each output stage from the vertical shift register (51) is converted into a scanning signal having a desired amplitude via a buffer unit (52) in which a plurality of inverters (57) are connected in series. The signal is output to the gate line (GL) of each corresponding row in the display area (4), and is commonly input to the gate of each pixel TFT (SE) in the same row.

FIG. 3 is an equivalent circuit diagram of the drain driver units (61, 62). The lower stage is a bidirectional horizontal shift register (61), and the upper stage is a sampling unit (62). Each stage of the horizontal shift register (61) includes a first clocked inverter (63), an inverter (64), and a second clocked inverter (65) connected in parallel to the inverter (64) in the opposite direction. The output from each of these output stages is sent to a sampling unit (62) via a buffer unit in which a plurality of inverters (66) are connected in series. The sampling section (62) includes an analog switch (67) having a gate connected to each corresponding stage of the buffer section (66), and a video line (68) on which an original image signal from the outside is placed. The analog switch (67) is connected to the video line (68), and its on / off is controlled by the output from each stage of the horizontal shift register (61), and the display to be supplied from the original image signal to each display pixel. The signal is sampled, output to the drain line (DL) of each corresponding column of the display area (4), and supplied to the pixel TFT (SE) of the same column.

In the present invention, as shown in FIG. 1, a part of the sealing material (3) passes over the drain driver, in particular, the horizontal shift register (61), and its edge line is the horizontal shift register (61). The upper region is linear. The horizontal shift register (61) has one shift register circuit provided over the entire side of the display area (4) in the figure, or has a plurality of shift register circuits connected in series over the entire side. Is provided. In any case, the sealing material (3) passes over the horizontal shift register (61) with a straight edge line over the entire area on the horizontal shift register (61) with respect to the same side. For this reason, even if the characteristics of the TFT element immediately below the sealing material (3) fluctuate and the characteristics of the TFT element immediately below the sealing material (3) and the other area are different, the characteristics of the horizontal shift register (61) are changed. Differences in operating characteristics between the stages are prevented. Therefore, even in the display area (4), areas having different displays in the column direction are not mixed.

Similarly, also on the gate driver side, a part of the sealing material (3) passes over the vertical shift register (51) over the entire vertical side of the display area (4) in the figure, but its edge line is vertically shifted. It is linear on the register (51). For this reason, even if the characteristics of the TFT element immediately below the sealing material (3) fluctuate, the operation characteristics are prevented from being different between the stages of the vertical shift register (51), and the display region (4) is also prevented from changing in the line spacing direction. Regions with different displays are not mixed.

In addition, since the seal member (3) avoids the control circuit (7), it is possible to prevent the control circuit (7) from malfunctioning and to switch the operation direction of the driver (5, 6). It can be done freely.

Further, since the curved portion of the sealing material (3) is not present in any area on the driver (5, 6) or the control circuit (7), even if the curved portion of the sealing material (3) is stressed, it is displayed. Is prevented from being affected.

FIG. 4 is a partial plan view of the liquid crystal display device according to the second embodiment of the present invention. In the present embodiment, the entire width of the sealing material (3) passes over the drain driver including the horizontal shift register (61) and the sampling unit (62). The edge line of the sealing material (3) is linear. For this reason, even if the characteristics of the TFT element are different between the region immediately below the sealing material (3) and the other region, there is no difference in operation between the steps of the drain drivers (61, 62), and the display region is not changed. In (4), the display is prevented from being different between columns.

In particular, in the present embodiment, the outer edge line of the sealing material (3) in FIG. 4 is more specifically, as shown by the X-ray in FIG. 63, 64, 65) and the buffer section (66). That is, the buffer section (66) is located immediately below the sealing material (3), and the shift register circuit sections (63, 64, 65) are located outside the sealing material (3). Fluctuations in the threshold of the TFT element immediately below the sealing material (3) may affect the logic operation. However, in the buffer section (66), as long as there is no difference between the stages, the shift register circuit section (63, 64) , 65) is not affected by the threshold fluctuation. Similarly, the sampling section (67) is also less susceptible to the threshold fluctuation. For this reason, even if the sealing material (3) passes over the drain drivers (61, 62), especially when the sealing material (3) avoids the shift register circuits (63, 64, 65), the shift register circuits (63, 62) do not. 64, 65), the buffer section (66) and the sampling section (62) output a display signal with an accurate amplitude, and the drain driver (61, 62) operates satisfactorily as a whole. Is performed.

Similarly, on the gate driver side, the entire width of the sealing material (3) passes over the gate driver including the vertical shift register (51) and the sampling unit (52). The edge line of the sealing material (3) in the upper region is linear. Therefore, even if the characteristics of the TFT elements are different between the area immediately below the sealing material (3) and the other area, there is no difference in operation between the stages, and the display is different between rows in the display area (4). Can be prevented. Particularly, as shown by X-rays in FIG. 2, the outer edge of the sealing material (3) is located inside the shift register circuit section (53, 54, 55). Accordingly, it is possible to prevent the threshold value fluctuation of the TFT element from affecting the logical operation of the shift register (53, 54, 55). Further, by setting the outer edge line of the sealing material (3) inside the AND gate (56), the stability is further improved. Further, even if the sealing material (3) is on the buffer section (52), there is no influence of the threshold value fluctuation.

FIG. 5 is a partial plan view of the liquid crystal display device according to the third embodiment of the present invention.
In the present embodiment, the sealing material (3) passes over the drain driver. In particular, the entire width is located on the horizontal shift register (61), and in the region above the horizontal shift register (61). The edge line of the sealing material (3) is straight. Similarly, on the gate driver side, the entire width of the sealing material (3) is located on the vertical shift register (51), and the edge of the sealing material (3) is located above the vertical shift register (51). Are linear. Therefore, even if the characteristics of the TFT element are different between the area immediately below the sealing material (3) and the other area, there is no difference in operation between the steps, and the display in the display area (4) is prevented from being different. It is.

FIG. 6 is a partial plan view of a liquid crystal display according to a fourth embodiment of the present invention.
In the present embodiment, the sealing material (3) passes over the drain driver, but is particularly located so as to entirely cover the sampling section (62). As long as the operation of the analog switch (67) does not differ between the stages, the fluctuation of the threshold does not affect the sampling, thereby preventing the display from being different between columns. Further, the sealing material (3) is located so as to cover the entire buffer portion (52) of the gate driver. In this case as well, even if the threshold value of the TFT element constituting the inverter (57) fluctuates, the display is performed. Has no effect.

(4) Further, since the sealing material (3) is avoided on the control circuit (7), it is possible to prevent the switching operation of the driver from becoming defective.

FIG. 7 is a partial plan view of the liquid crystal display device according to the fifth embodiment of the present invention.
In the present embodiment, the sealing material (3) passes over the drain driver, but is provided so as to entirely cover the horizontal shift register (61). For this reason, since all the TFT elements in the horizontal shift register (61) are affected by the same threshold value fluctuation, there is no difference in operation between the stages, and as a result, the column in the display area (4) It is possible to prevent areas having different displays from being mixed. Similarly, the gate driver is provided so as to cover the entire vertical shift register (51), so that the display area (4) is prevented from having different display areas between rows in the display area (4).

FIG. 8 is a partial plan view of the liquid crystal display device according to the sixth embodiment of the present invention.
In the present embodiment, the sealing material (3) is provided so as to cover all of the drain driver including the horizontal shift register (61) and the sampling unit (62). For this reason, since all the TFT elements in the drain drivers (61, 62) are affected by the same threshold value fluctuation, there is no difference in operation between the stages, and as a result, in the display area (4), It is possible to prevent areas having different displays from being mixed between columns. Further, the sealing material (3) is provided so as to cover all of the gate driver including the vertical shift register (51) and the buffer unit (66). For this reason, since all the TFT elements in the gate drivers (51, 52) are affected by the same threshold fluctuation, there is no difference in operation between the stages, and as a result, in the display area (4), It is possible to prevent areas having different displays from being mixed between lines.

FIG. 9 is a partial plan view of the liquid crystal display device according to the seventh embodiment of the present invention.
In the present embodiment, since the sealing material (3) is provided so as to bypass the outside of the drain driver (61, 62) or the gate driver (51, 52), the threshold value variation of the TFT element due to the sealing material (3). The display is completely free of any adverse effects. In addition, since the seal member (3) avoids the control circuit (7), it is possible to prevent the switching of the operation direction of the driver from being disabled.

FIG. 10 is a partial plan view of the liquid crystal display device according to the eighth embodiment of the present invention.
In the present embodiment, since the sealing material (3) is provided so as to bypass the inside of the drain driver (61, 62) or the gate driver (51, 52), the threshold value variation of the TFT element due to the sealing material (3). There is no harmful effect on the display. In addition, since the seal member (3) avoids the control circuit (7), it is possible to prevent the switching of the operation direction of the driver from being disabled.

In each of the embodiments of the present invention described above, the case where the control circuit is provided is described. However, even when the control circuit is not provided, the shift register can be prevented from malfunctioning due to the influence of the adhesive. That is, the effect of the present invention can be obtained.

FIG. 2 is a partial plan view of the liquid crystal display device according to the first embodiment of the present invention. FIG. 2 is a partial equivalent circuit diagram of the liquid crystal display device according to the embodiment of the present invention. FIG. 2 is a partial equivalent circuit diagram of the liquid crystal display device according to the embodiment of the present invention. FIG. 5 is a partial plan view of a liquid crystal display device according to a second embodiment of the present invention. FIG. 9 is a partial plan view of a liquid crystal display device according to a third embodiment of the present invention. FIG. 14 is a partial plan view of a liquid crystal display device according to a fourth embodiment of the present invention. FIG. 15 is a partial plan view of a liquid crystal display device according to a fifth embodiment of the present invention. FIG. 14 is a partial plan view of a liquid crystal display device according to a sixth embodiment of the present invention. FIG. 15 is a partial plan view of a liquid crystal display device according to a seventh embodiment of the present invention. It is a partial top view of the liquid crystal display concerning an 8th embodiment of the present invention. It is a top view of a liquid crystal display device. FIG. 10 is a partial plan view of a conventional liquid crystal display device.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 TFT substrate 2 Counter substrate 3 Sealing material 4 Display area 5 Gate driver 6 Drain driver 7 Control circuit 8 Input terminal 9 Common electrode 51 Vertical shift register 52 Output buffer unit 61 Horizontal shift register 62 Sampling unit

Claims (4)

A display region on which a pixel electrode group arranged in a matrix and a first thin film transistor group for supplying a display signal voltage to each pixel electrode are formed on a facing surface; a second thin film transistor formed around the display region A first substrate provided with a plurality of drive circuit regions each of which is configured to drive the first thin film transistor and a control circuit region for controlling the drive circuit; and a second substrate on which a common electrode is formed. However, in a display device that is bonded by sandwiching an optical member with an adhesive provided on the periphery,
The driving circuit includes a shift register having a shift register circuit section and a buffer section, and an outer edge line of the adhesive is located between the shift register circuit section and the buffer section. Display device. The display device according to claim 1, wherein the adhesive has an outer edge line provided in a straight line extending in a long side direction of the drive circuit. The display device according to claim 1, wherein the adhesive is provided so as to avoid the control circuit area. The drive circuit includes at least a shift register and a drive signal output unit based on an output from each output stage of the shift register, and the adhesive is provided to avoid the shift register area and / or the control circuit area. The display device according to any one of claims 1 to 3, wherein: