USOO7385,665B2
`
`(12) United States Patent
`Matsumoto
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,385,665 B2
`Jun. 10, 2008
`
`(54) DISPLAY DEVICE
`(75) Inventor: Tomohiro Matsumoto, Kumagaya (JP)
`(73) Assignee: Toshiba Matsushita Display
`Technology Co., Ltd., Tokyo (JP)
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`(21) Appl. No.: 11/553,274
`
`(22) Filed:
`
`Oct. 26, 2006
`
`(65)
`
`Prior Publication Data
`US 2007/009.7309 A1
`May 3, 2007
`
`Foreign Application Priority Data
`(30)
`Oct. 31, 2005 (JP)
`............................. 2005-317079
`
`(51) Int. Cl.
`(2006.01)
`H05K L/00
`(52) U.S. Cl. ........................ 34.9/150; 349/149; 349/33;
`439/55; 439/951; 174/250; 257/59
`(58) Field of Classification Search ................ 34.9/150,
`349/149,33; 174/250, 255; 345/88: 257/59;
`439/55,951
`See application file for complete search history.
`References Cited
`
`(56)
`
`U.S. PATENT DOCUMENTS
`6,583,845 B1* 6/2003 Chung et al. ............... 349,150
`2001/0026345 A1 * 10, 2001 Park et al. .................. 349,149
`2004.0036833 A1
`2/2004 Monzen
`
`7/2005 Yoon et al. ................... 349,33
`2005/O162577 A1*
`4/2006 Ho et al. .......
`... 174/250
`2006/0O86532 A1*
`6/2006 Kim et al. .................... 257/59
`2006/O118786 A1*
`2006/0232533 A1* 10/2006 Miyazawa .....
`... 345,88
`2007/0085960 A1* 4/2007 Kim ........................... 349,149
`
`FOREIGN PATENT DOCUMENTS
`
`9, 2005
`9, 2001
`3, 2004
`
`2005-241852
`JP
`2001-0083972
`KR
`2004-00182O1
`KR
`* cited by examiner
`Primary Examiner Gary F. Paumen
`(74) Attorney, Agent, or Firm Oblon, Spivak, McClelland,
`Maier & Neustadt, P.C.
`
`ABSTRACT
`(57)
`A display device includes a display panel which includes an
`effective display section, a flexible board which supplies a
`driving signal to the effective display section, a connection
`part at which the display panel and the flexible board are
`connected, and a plurality of connection wiring lines which
`connect the connection part and the effective display section.
`The connection part includes a first connection section
`including at least two connection pad groups, which are
`composed of connection pads that are connected to the
`effective display section via the connection wiring lines, and
`a dummy pad group which is disposed between the connec
`tion pad groups, and is composed of dummy pads, and a
`second connection section including connection terminal
`groups, which are composed of connection terminals corre
`sponding to the connection pads, and a dummy terminal
`group which is composed of dummy terminals correspond
`ing to the dummy pads.
`
`4 Claims, 7 Drawing Sheets
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`Tianma Exhibit 1001
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`U.S. Patent
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`Jun. 10, 2008
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`Sheet 1 of 7
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`U.S. Patent
`U.S. Patent
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`Jun. 10, 2008
`Jun.10,2008
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`U.S. Patent
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`Jun. 10, 2008
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`U.S. Patent
`U.S. Patent
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`Jun. 10, 2008
`Jun.10,2008
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`U.S. Patent
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`Jun. 10, 2008
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`U.S. Patent
`U.S. Patent
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`Jun. 10, 2008
`Jun.10,2008
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`U.S. Patent
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`Jun. 10, 2008
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`Sheet 7 Of 7
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`US 7,385,665 B2
`
`1.
`DISPLAY DEVICE
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is based upon and claims the benefit of
`priority from prior Japanese Patent Application No. 2005
`317079, field Oct. 31, 2005, the entire contents of which are
`incorporated herein by reference.
`
`10
`
`BACKGROUND OF THE INVENTION
`
`15
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`25
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`30
`
`35
`
`1. Field of the Invention
`The present invention relates generally to a display
`device, and more particular to an active-matrix display
`device.
`2. Description of the Related Art
`In general, a display device includes a display panel
`having an effective display section in which a plurality of
`display pixels are arranged. The display panel includes a
`plurality of Scanning lines for selecting the display pixels,
`and a plurality of signal lines for Supplying image signals to
`the selected display pixels. A driving IC, which Supplies
`driving signals to the signal lines and scanning lines, has the
`same number of driving signal output lines as the number of
`the signal lines and Scanning lines.
`In recent years, liquid crystal display devices, for
`instance, have widely been used as display devices. In order
`to meet a demand to accommodate a display panel in a
`limited space within the housing of the device and a demand
`to increase the amount of information to be displayed, such
`a structure has been desired that the display region is
`increased as large as possible while the picture-frame
`shaped region of the display device is reduced in size.
`As a method for decreasing the size of the picture-frame
`shaped region of the display device, there has been proposed
`in the prior art a method in which the positional relationship
`between the driving IC, a flexible board and their lead lines
`is improved (see Jpn. Pat. Applin. KOKAI Publication No.
`11-305254).
`However, even if the positional relationship between the
`driving IC, etc. is improved as in the above-mentioned liquid
`crystal display device, an increase in the number of signal
`lines and Scanning lines leads to an increase in length of
`45
`connection wiring between the flexible board and the signal
`lines, etc. As a result, the size of the picture-frame-shaped
`region of the display device would increase.
`In addition, there is a limit to the length of the connection
`part between the flexible board and an array substrate of the
`display device in the direction in which connection terminals
`are arranged. Thus, if connection terminals, the number of
`which is equal to that in the prior art, are disposed with a
`pitch less than in the prior art, a region where there is no
`connection terminal would occur on the connection part. In
`this case, when the flexible board is thermal press-bonded to
`the array substrate, defective connection of the flexible
`board may occur in the region where there is no connection
`terminal.
`
`40
`
`50
`
`55
`
`BRIEF SUMMARY OF THE INVENTION
`
`The present invention has been made in consideration of
`the above-described problem, and the object of the invention
`is to provide a display device which enables reduction in size
`of a picture-frame-shaped region and prevents defective
`connection of a flexible board.
`
`60
`
`65
`
`2
`According to an aspect of the present invention, there is
`provided a display device comprising: a display panel which
`includes an effective display section on which an image is
`displayed; a driving signal Source which Supplies a driving
`signal to the effective display section; a connection part at
`which the display panel and the driving signal source are
`connected; and a plurality of connection wiring lines which
`connect the connection part and the effective display section,
`the connection part comprising: a first connection section
`including at least two connection pad groups which are
`composed of connection pads that are connected to the
`effective display section via the connection wiring lines, and
`a dummy pad group which is disposed between the at least
`two connection pad groups and is composed of dummy
`pads; and a second connection section including connection
`terminal groups which are composed of connection termi
`nals corresponding to the connection pads, and a dummy
`terminal group which is composed of dummy terminals
`corresponding to the dummy pads.
`The present invention can provide a display device which
`enables reduction in size of a picture-frame-shaped region
`and prevents defective connection of a flexible board.
`Additional objects and advantages of the invention will be
`set forth in the description which follows, and in part will be
`obvious from the description, or may be learned by practice
`of the invention. The objects and advantages of the invention
`may be realized and obtained by means of the instrumen
`talities and combinations particularly pointed out hereinaf
`ter.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRAWING
`
`The accompanying drawings, which are incorporated in
`and constitute a part of the specification, illustrate embodi
`ments of the invention, and together with the general
`description given above and the detailed description of the
`embodiments given below, serve to explain the principles of
`the invention.
`FIG. 1 is a plan view that schematically shows an example
`of a liquid crystal display panel of a liquid crystal display
`device according to an embodiment of the present invention;
`FIG. 2 is a view for describing an example of the structure
`of a connection part between an array Substrate of the liquid
`crystal display panel and a flexible board;
`FIG. 3A is a view for describing an example of arrange
`ment of connection pads of the connection part of the array
`substrate shown in FIG. 2;
`FIG. 3B is a view for describing an example of arrange
`ment of the connection pads in a case where the pitch of
`arrangement of the connection pads is decreased in the
`connection part shown in FIG. 2;
`FIG. 3C shows in detail an example of the structure of the
`connection part of the array substrate shown in FIG. 2;
`FIG. 3D shows in detail another example of the structure
`of the connection part of the array substrate shown in FIG.
`2:
`FIG. 4 is a view for describing an example of the structure
`of the connection part between the array substrate and
`flexible board of the liquid crystal display panel shown in
`FIG. 1;
`FIG. 5A is a cross-sectional view, taken along line A-A in
`FIG. 1, showing an example of the cross-sectional structure
`of the liquid crystal display panel shown in FIG. 4;
`FIG. 5B is a cross-sectional view, taken along line A-A in
`FIG. 1, showing another example of the cross-sectional
`structure of the liquid crystal display panel shown in FIG. 4;
`
`Page 9 of 12
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`US 7,385,665 B2
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`3
`FIG. 6 shows an Example of the liquid crystal display
`device according to the embodiment of the present inven
`tion; and
`FIG. 7 is a view for describing a liquid crystal display
`device according to a Comparative Example for comparison
`with the embodiment shown in FIG. 4.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`4
`If the connection part TA and the connection wiring lines
`CW are arranged as described above, a Y-directional length
`L2 of the first wiring region WA1 and second wiring region
`WA2 increases. As a result, a Y-directional length L3
`between the edge portion 12E of the array substrate 12 and
`the effective display section 10A increases.
`To cope with this problem, the pitch of arrangement of
`connection pads CP on the liquid crystal display panel 10
`shown in FIG. 1 and FIG. 2 is decreased. For example, on
`the liquid crystal display panel 10 shown in FIG. 1 and FIG.
`2, the connection pads CP are arranged with a pitch P1 as
`shown in FIG. 3A. By decreasing the pitch P1, the connec
`tion pads CP are arranged with a pitch P2 (P1 >P2) as shown
`in FIG. 3B. In this case, the connection pads CP comprises
`two connection pad groups, that is, a first connection pad
`group PA1 and a second connection pad group PA2. The first
`and second connection pad groups PA1 and PA2 are dis
`posed on both end portions of the first connection section
`TA1.
`Accordingly, as shown in FIG. 4, the pitch of arrangement
`of the connection terminals CT of the flexible substrate 16,
`which correspond to the connection pads CP decreases, and
`two connection terminal groups, that is, a first connection
`terminal group CTA1 and a second connection terminal
`group CTA2, are disposed on both end portions of the
`second connection section TA2 of the flexible board 16.
`To be more specific, as shown in FIG. 4, the array
`substrate 12 and flexible board 16 are arranged such that the
`first connection pad group PA1 of the array substrate 12 is
`opposed to the first connection terminal group CTA1 of the
`flexible board 16, and the second connection pad group PA2
`of the array substrate 12 is opposed to the second connection
`terminal group CTA2 of the flexible board 16.
`As described above, if the pitches of the connection pads
`CP and connection terminals CT are decreased and the
`connection pad groups and connection terminal groups are
`disposed on end portions in the X direction of the connection
`part TA, the connection wiring lines CW extend from the
`respective connection pad groups to the right and left
`directions.
`Specifically, as shown in FIG. 4, the second wiring region
`WA2, which extends from the first connection pad group
`PA1, includes connection wiring lines CW which extend
`from the first wiring region WA1 to the left toward the
`effective display section 10A, and connection wiring lines
`CW which extend from the first connection pad group PA1
`to the right toward the effective display section 10A.
`Similarly, the second wiring region WA2, which extends
`from the second connection pad group PA2, includes con
`nection wiring lines CW which extend from the first con
`nection region WA1 to the left and right toward the effective
`display section 10A.
`Accordingly, there are provided not only a region where
`the connection wiring lines CW extend toward the end
`portions in the X direction of the array substrate 12, but also
`a region where the connection wiring lines CW extend
`toward the center of the array substrate 12. Thus, the number
`of connection wiring lines CW, which extend toward the end
`portions in the X direction of the effective display section
`10A, decreases. Hence, the length L2 in the Y direction of
`the first wiring region WA1 and second wiring region WA2
`can be decreased, and as a result the distance L3 between the
`edge portion 12E of the array substrate 12 and the effective
`display section 10A can be decreased.
`The X-directional length of the second connection section
`TA2 of the flexible board 16 is limited. Thus, if the pitch of
`arrangement of the connection pads CP is decreased as
`
`10
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`15
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`25
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`30
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`As is shown in FIG. 1, a liquid crystal display device,
`which serves as a display device, includes a liquid crystal
`display panel 10 having an effective display section 10A
`which displays an image.
`The liquid crystal display panel 10 includes a pair of
`mutually opposed substrates, that is, an array Substrate 12
`and a counter-substrate 14, and a liquid crystal layer (not
`shown) which is held between the array substrate 12 and
`counter-substrate 14. The effective display section 10A is
`composed of a plurality of display pixels PX which are
`arrayed in a matrix.
`On the array Substrate 12, a plurality of Scanning lines SL
`(SL1 to SLm) are disposed along the rows of display pixels
`PX, and a plurality of signal lines DL (DL1 to DLn) are
`disposed along the columns of display pixels PX. In the
`example shown in FIG. 1, 432 signal lines are disposed on
`the array substrate 12.
`The array substrate 12 includes an extension part 12A
`which extends from a position where the array substrate 12
`is opposed to an edge portion 14E of the counter-substrate
`14. A connection part TA, to which a driving signal Source
`that supplies a driving signal to the effective display section
`10A is connected, is disposed on the extension part 12A.
`Specifically, a flexible board 16, which functions as the
`driving signal Source, is connected to the connection part
`TA. A driving circuit DC is mounted on the flexible board.
`As is shown in FIG. 2, a first connection section TA1 of
`the array Substrate 12 and a second connection section TA2
`of the flexible board 16 are connected at the connection part
`TA. The first connection section TA1 of the array substrate
`12 includes a plurality of connection pads CP which are
`connected to the effective display section 10A by connection
`wiring lines CW. In the example shown in FIG. 2, the first
`connection section TA1 includes 432 connection pads. CP
`which are connected to connection wiring lines extending to
`45
`the 432 signal lines.
`The array substrate 12 includes a wiring region WA on
`which the connection wiring lines CW are disposed. The
`wiring region WA includes a first wiring region WA1 in
`which connection wiring lines CW extend in a direction (Y
`50
`direction) which is Substantially perpendicular to an edge
`portion 12E of the array substrate 12, and a second wiring
`region WA2 in which connection wiring lines CW extend
`from the first wiring region WA1 toward the signal lines DL.
`In the example shown in FIG. 2, the second wiring region
`WA2 extends from an end portion of the first connection
`section TA1 in a widening fashion toward both end portions
`in an X direction of the effective display section 10A.
`Connection terminals CT, which correspond to the con
`nection pads CP of the first connection section TA1, are
`disposed on the second connection section TA2 of the
`flexible board 16. Specifically, in the example shown in FIG.
`2, 432 connection terminals CT, which correspond to the 432
`connection pads CP of the first connection section TA1, are
`disposed on the second connection section TA2 with the
`same pitch as the pitch of arrangement of the connection
`pads CP.
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`5
`described above, a region A1, where no connection pad CP
`is disposed, is formed on the first connection section TA1, as
`shown in FIG. 3B. Accordingly, a region A2 (corresponding
`to CTA3 in FIG. 4 to FIG. 6), where no connection terminal
`CT is disposed, is formed on the second connection section
`TA2 of the flexible board 16 in association with the region
`A1 where no connection pad CP is disposed.
`In this case, if the flexible board 16 is thermal press
`bonded on the array substrate 12, a thermal distribution on
`the connection part TA becomes non-uniform, leading to
`possible defective connection. To cope with this problem, as
`shown in FIG. 3C, a plurality of dummy pads DP, which are
`not connected to the connection wiring lines CW, are dis
`posed on the region A1 where no connection pad CP is
`disposed.
`Specifically, as shown in FIG. 5A, in the first connection
`part TA1, there are provided the first and second connection
`pad groups PA1 and PA2, which are composed of the
`connection pads CP, and a third connection pad group PA3
`which is disposed between the first connection pad group
`PA1 and second connection pad group PA2 and is composed
`of dummy pads DP.
`In this case, as shown in FIG. 3C, a pitch P3 of the dummy
`pads DP is equal to the pitch P2 of the connection pads CP.
`In accordance with this, in the second connection section
`TA2 of the flexible board 16, as shown in FIG. 5A, dummy
`terminals DT, which are opposed to the dummy pads DP are
`disposed on the region A2 where no connection terminal CT
`is disposed, which is interposed between the first connection
`terminal group CTA1 and second connection terminal group
`CTA2.
`To be more specific, as shown in FIG. 6, in the second
`connection part TA2, there are provided the first and second
`connection terminal groups CTA1 and CTA2, which are
`composed of the connection terminals CT, and a third
`connection terminal group CTA3 which is disposed between
`the first connection terminal group CTA1 and second con
`nection terminal group CTA2 and is composed of dummy
`terminals DT.
`As described above, the third connection pad group PA3
`comprising the dummy pads DP is disposed between the first
`and second connection pad groups PA1 and PA2 which are
`structural components of the first connection section TA1,
`and the third connection terminal group CTA3 comprising
`the dummy terminals DT is disposed between the first and
`second connection terminal groups CTA1 and CTA2 which
`are structural components of the second connection section
`TA2. Thereby, even if the pitch of arrangement of the
`connection pads CP is decreased, the thermal distribution at
`the time of thermal press-bonding can be made uniform and
`defective connection can be prevented.
`An Example of the present invention and a Comparative
`Example of the invention will now be described. Each of
`liquid crystal display panels according to the Example and
`Comparative Example includes an effective display section
`10A having an X-directional length of 331 mm, 432 con
`nection pads CP and 432 connection terminals CT. In
`addition, the X-directional length L1 of the second connec
`tion section TA2 of the flexible board 16 is 39 mm.
`The liquid crystal display device according to the
`Example includes a liquid crystal display panel 10 as shown
`in FIG. 6. Specifically, connection wiring lines CW are
`connected to the signal lines DL via a switch circuit SWC
`which includes Switching elements that are formed by using
`polysilicon. In the Example, 432 connection wiring lines
`CW are connected to 1296 signal lines DL (DL1 to DL1296)
`via the Switch circuit SWC.
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`US 7,385,665 B2
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`10
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`6
`Except for the above-described respects, this liquid crys
`tal display panel 10 is the same as the liquid crystal display
`panel shown in FIG.1. Thus, the common parts are denoted
`by like reference numerals, and a description thereof is
`omitted. As shown in FIG. 4, the array substrate 12 includes
`first to third connection pad groups PA1, PA2 and PA3. The
`number of connection pads CP of each of the first and second
`connection pad groups PA1 and PA2 is 216, and these
`connection pads CP are arranged with a pitch of 65 Lum. In
`the third connection pad group PA3, 118 dummy pads DP
`are arranged with a pitch of 65 Lum.
`The second connection section TA2 of the flexible board
`16 includes first to third connection terminal groups CTA1,
`CTA2 and CTA3 in association with the first connection
`section TA1. In the first and second connection terminal
`groups CTA1 and CTA2, connection terminals are arranged
`with the same pitch as the pitch of the connection pads. In
`the third connection terminal group CTA3, dummy termi
`nals DT are arranged with the same pitch as the pitch of the
`dummy pads DP.
`In this case, the Y-directional length L2 of each of the first
`wiring region WA1 and second wiring region WA2 was 5.3
`mm, and the Y-directional length L3 between the edge
`portion 12E of the array substrate 12 and the effective
`display section 10A was about 5.8 mm.
`In the liquid crystal display device according to the
`Comparative Example, like the device shown in FIG. 6, the
`connection wiring lines CW of the array substrate 12 are
`connected to the signal lines DL via the switch circuit SWC.
`Specifically, as shown in FIG. 7,432 connection wiring lines
`CW are connected to 1296 signal lines DL via the switch
`circuit SWC.
`In the first connection section TA1, 432 connection pads
`CP are arranged with a pitch of 80 Lum. In the second
`connection section TA2 of the flexible board 16, the con
`nection terminals CT are arranged with the same pitch as the
`pitch of the connection pads CP on the first connection
`section TA1. In this Comparative Example, except for the
`above-described points, the liquid crystal display panel 10
`has the same structure as the display panel 10 shown in FIG.
`1, so the common parts are denoted by like reference
`numerals and a description thereof is omitted.
`In this case, the Y-directional length L2 of each of the first
`wiring region WA1 and second wiring region WA2 was 5.9
`mm, and the Y-directional length L3 between the edge
`portion 12E of the array substrate 12 and the effective
`display section 10A was about 6.4 mm.
`Specifically, in the Example of the invention, compared to
`the Comparative Example, the Y-directional length L2 of
`each of the first wiring region WA1 and second wiring
`region WA2 was successfully reduced by 10%, and as a
`result the Y-directional length L3 between the edge portion
`12E of the array substrate 12 and the effective display
`section 10A could be reduced by 9.4%. Thus, this Example
`can provide the liquid crystal display device which enables
`reduction in size of a picture-frame-shaped region of the
`liquid crystal display panel 10 and prevents defective con
`nection of the flexible board 16.
`The present invention is not limited directly to the above
`described embodiments. In practice, the structural elements
`can be modified without departing from the spirit of the
`invention.
`In the liquid crystal display device according to the
`embodiment, the invention has been applied to the arrange
`ment of connection wiring lines that are connected to the
`signal lines. Alternatively, the invention may be applied to
`the arrangement of the scanning lines. In this case, too, the
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`same advantageous effect as with the above-described
`embodiment can be obtained.
`In the liquid crystal display device according to the
`embodiment, each of the pitch of the connection pads. CP
`and the pitch of the dummy pads DP is 65um. However, the
`pitch of the dummy pads DP may be different from the pitch
`of the connection pads CP. For example, as shown in FIG.
`3D and FIG. 5B, the dummy pads DP may be arranged with
`the pitch P1 and the connection pads CP may be arranged
`with the pitch P2 (P1 > P2). In this case, too, the same
`advantageous effect as with the above-described embodi
`ment can be obtained.
`Various inventions can be made by properly combining
`the structural elements disclosed in the embodiments. For
`example, Some structural elements may be omitted from all
`the structural elements disclosed in the embodiments. Fur
`thermore, structural elements in different embodiments may
`properly be combined.
`What is claimed is:
`1. A display device comprising:
`a display panel which includes an effective display section
`on which an image is displayed;
`a driving signal source which Supplies a driving signal to
`the effective display section;
`a connection part at which the display panel and the
`driving signal source are connected; and
`a plurality of connection wiring lines which connect the
`connection part and the effective display section,
`the connection part comprising:
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`10
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`15
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`25
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`US 7,385,665 B2
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`5
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`8
`a first connection section including at least two connec
`tion pad groups which are composed of connection
`pads that are connected to the effective display section
`via the connection wiring lines, and a dummy pad
`group which is disposed between the at least two
`connection pad groups and is composed of dummy
`pads; and
`a second connection section including connection termi
`nal groups which are composed of connection terminals
`corresponding to the connection pads, and a dummy
`terminal group which is composed of dummy terminals
`corresponding to the dummy pads.
`2. The display device according to claim 1, wherein a
`pitch of arrangement of the dummy pads is equal to, or
`greater than, a pitch of arrangement of the connection pads.
`3. The display device according to claim 1, wherein the
`effective display section includes a plurality of signal Supply
`lines which Supply signals to display pixels, and a Switch
`circuit which Switches and connects the plurality of signal
`Supply lines to the connection wiring lines, and
`the Switch circuit includes Switching elements which are
`formed by using polysilicon.
`4. The display device according to claim 1, wherein the
`display panel includes a pair of mutually opposed substrates,
`and a liquid crystal composition which is held between the
`pair of Substrates.
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