CN1467698A

CN1467698A - Display

Info

Publication number: CN1467698A
Application number: CNA021410534A
Authority: CN
Inventors: 吉田毅昌
Original assignee: NEC LCD Technologies Ltd
Current assignee: Tianma Japan Ltd
Priority date: 2002-07-12
Filing date: 2002-07-12
Publication date: 2004-01-14
Anticipated expiration: 2022-07-12
Also published as: CN100405447C

Abstract

A linking substrate of the crystal display supported by a first supporting member and a second supporting member, wherein a first septum and a septum will be spaced apart at a predetermined distance that can regulate the unnecessary electromagnetic radiation.

Description

Display

Technical field

The present invention relates to a kind of flat display of for example colour liquid crystal display device, more specifically, the present invention relates to a kind of flat display that limits unnecessary electromagnetic radiation, this unnecessary electromagnetic radiation meeting causes EMI (electromagnetic interference (EMI)) etc.

Background technology

As a kind of flat display, the colour liquid crystal display device of active matrix system for example, comprises a LCD panel and a back-lighting light source (backlight) that illuminates surface under the LCD panel.Horizontal drive circuit substrate and vertical drive circuit substrate are arranged on the outside of the periphery of LCD panel.In addition, the signal Processing substrate is arranged on the rear surface side of LCD panel, and the picture intelligence that the signal Processing substrate is supplied with the outside is converted to horizontal drive signals and by connecting substrate horizontal drive signals is offered at the on-chip liquid crystal drive IC of horizontal drive circuit.Hold LCD panel, back-lighting light source, level and vertical drive circuit substrate in the box that barricade constitutes after by preceding shielding and metal.Before sheet metal be made of metal and have display window, barricade is used to hold and the back-lighting light source is installed behind the metal.

Figure 1A is the skeleton view of an example of conventional LCD, the position relation of its LCD panel, horizontal drive circuit substrate and signal Processing substrate has been described, Figure 1B is that linkage unit is connected to horizontal LCD panel on the signal Processing substrate along the signal Processing substrate of planar extension and the planimetric map of linkage unit.Fig. 2 A and Fig. 2 B are the xsects that the line A-A ' along Figure 1A is got, and a part and the having of secondary shielding plate that will not connect the nail portion (nail portion) that substrate is fixed to the secondary shielding plate of having described the secondary shielding plate respectively will be connected the part that substrate is fixed to the nail portion of secondary shielding plate.By way of parenthesis, in order to simplify description, horizontal drive circuit substrate, preceding barricade, back barricade and back-lighting light source etc. are not shown in Figure 1A.Fig. 3 is the cross-sectional view of being got along Figure 1A center line B-B '.

Referring to Figure 1A to Fig. 3, conventional LCD 510 comprises: LCD panel 511, preceding barricade 531, the first back barricade, 533, the second back barricades 534, signal Processing substrate 521, adopt the horizontal drive circuit substrate 524 that horizontal drive IC526 is installed of TCP (tape carrier encapsulation) form thereon, connect substrate 523, flexible print circuit substrate (being called FPC hereinafter) 522 and the light diffusing sheet 513 that is used for evenly spreading from the light of back-lighting light source (not shown), or the like.In addition, horizontal drive circuit substrate 524 is called TCP hereinafter.

The periphery of display board 511 is non-display areas, by first liner 546 and second lining plank 547 periphery of display board 511 is clipped between the preceding barricade 531 and the second back barricade 534 respectively.By the first back barricade 533 hold with fixing light diffusing sheet 513, rear surface side (relative) that back-lighting light source (not shown) is arranged on LCD panel 511 with display surface on.

As shown in Figure 3, by insulating trip 555 signal Processing substrate 521 is fixed to the rear surface side of the first back barricade 533, will be connected substrate 523 and be fixed to second afterwards on the barricade 534 actually with in the vertical plane of the display surface of LCD panel 511 by insulating trip 551.Realize connecting the fixing of substrate 523 by at least one the nail portion 537 that is arranged on barricade 534 appropriate positions, second back, shown in Fig. 2 B.Be provided with nail portion 537 the second back barricade 534 part with connect substrate 523 do not form the regional corresponding of wiring diagram.In addition, signal Processing substrate 521 is comprised FPC522, is connected substrate 523 and TCP524, shown in Figure 1B with the linkage unit 520 that LCD panel 511 links to each other.

For example by using the thermocompression bonding of thermoplasticity anisotropic conductive film, the end (at output end) of TCP524 is bonded on the electrode of the marginal portion that is arranged at LCD panel 511, and for example is connected on the connection substrate 523 in input by the other end (distolateral) of welding with TCP524.Connecting substrate 523 and signal Processing substrate 521 interconnects by FPC522.

In addition, have the shell that at least one electrically conductive inner surface part and covering comprise the whole liquid crystal board rear surface of signal Processing substrate 521, be arranged on the rear surface side of LCD 510.Preceding barricade, the first back barricade and the second back barricade link to each other with the inner surface portion of shell.

In above-mentioned conventional LCD 510, can cause EMI etc. owing to be arranged on the electronic component on the vertical drive circuit substrate that do not illustrate among signal Processing substrate 521, TCP524 and/or the figure etc. and the unnecessary radiation of wiring, therefore the electrically conductive inner surface part of the shell by covering these elements to the major general links to each other with the public ground extension line (not shown) of LCD 510 and fetches the electromagnetic armouring structure that formation limits electromagnetic interference (EMI).

Yet along with the LCD frequency of operation is tending towards increasing, especially its horizontal drive circuit frequency is tending towards increasing, and unnecessary electromagnetic radiation just becomes problem, particularly transmits in the connection substrate of a large amount of horizontal drive signals along long wiring in limited zone.As Fig. 2 A, Fig. 2 B and shown in Figure 3, will connect substrate 523 by thin insulating sheet 551 and be fixed on the second back barricade 534, thereby keep its electrical isolation.Yet, have been found that, when a large amount of high-frequency signals flows in the connection substrate, owing to for example capacitive coupling makes signal leakage between the first back barricade 533 and the second back barricade 534, and unnecessary electromagnetic radiation by the first back barricade 533 and the second back barricade 534 with the form radiation of antenna.

Summary of the invention

An object of the present invention is to provide display as colour liquid crystal display device and so on, this display has such structure, even when in the connection substrate with limited wiring space during, also can limit the unnecessary electromagnetic radiation that causes EMI etc. along a large amount of high-frequency signal of long wiring transmission.

To achieve these goals, display according to the present invention is characterised in that and comprises: the display unit of at least one displayed image on the display unit front surface; Handle the signal processing unit that outside picture intelligence of supplying with and output are used for first signal of displayed image; Receive the driver element that first signal and output drive the secondary signal of display unit; The linkage unit that signal processing unit is connected with display unit; First screen unit by the conductive material manufacturing of for example metal and so on and have image display portion corresponding opening part with display unit, is used for the side surface area of electromagnetic screen external zones and visual display surface; The secondary shielding unit by the conductive material manufacturing of for example metal etc. and so on, is used for the whole rear side surface (rear side surface) of electromagnetic screen display unit.Linkage unit comprises: what link to each other with signal processing unit first flexibly connects part; Link to each other with display unit and with driver element mounted thereto second flexibly connect part; Connect substrate, be used for flexibly connecting part and second and flexibly connect part and interconnect first, the connection substrate remain between first screen unit and the secondary shielding unit respectively with the be separated by position of preset distance of first screen unit and secondary shielding unit.

Preferably, represent to be arranged on the distance that connects between on-chip first screen unit and the secondary shielding unit by L, be illustrated in along the center line of the thickness direction that connects substrate and the distance between first screen unit by d1 and d2 respectively, and connect the center line of substrate thickness direction and the distance between the secondary shielding unit on the edge.D1 and d2 satisfy following relation for L:

D1 〉=0.4 * L and d2 〉=0.4 * L.

Display can comprise first support component and second support component further, first support component is used to support the part connecting between the substrate and first screen unit, and second support component is used to support the part connecting between substrate and the secondary shielding unit.The height of first support component and second support component is equal to each other.First support component and second support component are preferably made by the non-conductive material (electrically non-conductive material) of for example silicon rubber and so on.

Display unit can be a LCD panel, and it comprises two substrates being faced each other by the predetermined space of being separated by therebetween, and liquid crystal material is between two substrates.

Description of drawings

Figure 1A is the skeleton view of an example of conventional LCD, describes the position relation between its LCD panel, horizontal crystal drive circuit substrate and the signal Processing substrate;

Figure 1B is along the signal Processing substrate of planar extension and the planimetric map of the linkage unit that horizontal LCD panel is linked to each other with the signal Processing substrate;

Fig. 2 A is the detailed cross sectional view that the line A-A ' along Figure 1A is got, and has described not connect the part that substrate is fixed to the nail portion of secondary shielding plate;

Fig. 2 B is the detailed cross sectional view that the line B-B ' along Figure 1A is got, and has described to have the part that at least one suitably is provided with nail portion;

Fig. 3 is the cross-sectional view that the line B-B ' along Figure 1A is got;

Fig. 4 is a cross-sectional view, has described the major part according to the LCD of the embodiment of the invention;

Fig. 5 is a cross-sectional view, has described the major part according to the LCD of the embodiment of the invention;

Fig. 6 A is a planimetric map, describes first example of the support component of the present invention's use;

Fig. 6 B is a planimetric map, describes second example of the support component of the present invention's use;

Fig. 6 C is the cross-sectional view that the line X1-X1 ' along Fig. 6 B is got;

Fig. 6 D is the cross-sectional view that the line Y1-Y1 ' along Fig. 6 A is got;

Fig. 6 E is the cross-sectional view that the line Y2-Y2 ' along Fig. 6 B is got;

Fig. 6 F is a planimetric map, describes the 3rd example of the support component of the present invention's use;

Fig. 6 G is a planimetric map, describes the 4th example of the support component of the present invention's use;

Fig. 6 H is the cross-sectional view that the line X2-X2 ' along Fig. 6 F and Fig. 6 G is got;

Fig. 6 I is the cross-sectional view that the line Y3-Y3 ' along Fig. 6 F is got;

Fig. 6 J is the cross-sectional view that the line Y4-Y4 ' along Fig. 6 G is got;

Fig. 7 is a curve map, shows the example from the measurement result of the unnecessary electromagnetic radiation of the LCD of the embodiment of the invention;

Fig. 8 is a block scheme of measuring the electromagnetic radiation measuring system that the unnecessary electromagnetic radiation of display uses.

Embodiment

The contrast accompanying drawing is described the present invention below.

Fig. 4 and Fig. 5 describe the cross-sectional view of the major part of LCD according to an embodiment of the invention; In addition, in the LCD of this embodiment, position between LCD panel, horizontal drive circuit substrate and signal Processing substrate relation is similar with the conventional LCD shown in Fig. 1, and Fig. 4 and Fig. 5 are the cross-sectional views of being got along line A-A ' and the B-B ' of Figure 1A respectively.

Referring to Fig. 4 and Fig. 5, the LCD 10 of present embodiment is by constituting as lower member in conjunction with Fig. 1: at least one LCD panel 11, as a display unit in front surface side displayed image; A signal Processing substrate 21 is as handling the outside signal processing unit of supplying with picture intelligence and exporting first signal that is used for displayed image; Drive IC 26 is exported the driver element of the secondary signal that drives LCD panel 11 in response from first signal of signal Processing substrate 21; First barricade 31 has the first metallic shield unit of opening portion as the image displaying area in LCD panel 11, is used for the external zones of electromagnetic screen LCD panel 11 and the side surface area of visual display surface side; The first back barricade 33 and the second back barricade 34 as metal secondary shielding unit, the whole rear surface side FPC22 that is used for covering liquid crystal display 11, flexibly connect part TCP24 as first of connection signal Processing substrate 22, as the substrate that is connected that connects FPC22 and TCP24; First support component 41 and second support component 42 are used for supporting respectively part and the part between the connection substrate 23 and the second back barricade 34 connecting between substrate 23 and the preceding barricade 31; The back-lighting light source that does not illustrate; With light diffusing sheet 13, be used for evenly diffusion from the light of back-lighting light source.In addition, the first back barricade 33 and the second back barricade 34 for example interconnect by the screw (not shown).And the linkage unit 20 that connects LCD panel 11 and signal-processing board 21 comprises FPC22, is connected substrate 23 and TCP24.

Similar with conventional LCD, use within it first liner 46 and second liner 47 respectively, the periphery of the LCD panel 11 of LCD 10 of the present invention is clipped between the preceding barricade 31 and the second back barricade 34.By the first back barricade 33 hold with fixing light diffusing sheet 13, rear surface side (relative) that back-lighting light source (not shown) is arranged on LCD panel 11 with display surface on.By insulating trip 55 for example signal Processing substrate 21 is fixed to the rear surface side of the first back barricade 33, by first support component 41 and second support component 43 support and connection substrate and make and connect substrate and be fixed in the in fact vertical plane between the preceding barricade 31 and the second back barricade 34 with the display surface of LCD panel 11.First support component 41 and second support component 43 can be formed by the non-conductive material of for example silicon rubber and so on.Limit by this way and connect substrate position in vertical direction, by L represent before barricade 31 and second the back barricade 34 facing surfaces between distance, be illustrated in along the distance between the surface of the center line 28 that connects substrate 23 thickness directions and preceding barricade 31 by d1 and d2 respectively, and along the center line 28 that connects substrate 23 thickness directions and with connect substrate 23 relative second after distance between the barricade 33.D1 and d2 satisfy following relation for L:

D1 〉=0.4 * L and d2 〉=0.4 * L

For example, in normal circumstances, d1 is identical with d2.In addition, represent the height of first support component 41 and second support component 42 respectively with h1 and h2, promptly connect the distance between substrate 23 and the preceding barricade 31 and be connected substrate 23 and secondary shielding substrate 34 between distance.Can limit h1 and h2 is h1=h2.

LCD panel 11 comprises: glass substrate 11a, and for example the mode with matrix forms a plurality of transistors on glass substrate; Has relative (opposing) substrate of (opposing) electrode relatively; Be clipped in the liquid crystal material layer (not shown) between above-mentioned two substrates that be arranged in parallel by predetermined space.For example by using the thermocompression bonding of thermoplastic conductive anisotropic membrane, the end (output end) of TCP24 is bonded on the electrode on the side surface portion of the glass substrate that is arranged at LCD panel 11, and for example the other end (distolateral in input) of TCP24 is connected to and connects on the substrate 23 by the hot pressing welding.Connecting substrate 23 and signal Processing substrate 521 interconnects by FPC522.

In addition, the LCD 10 of this embodiment comprises shell, and shell is arranged on the rear surface side.It is inboard that shell has at least one conduction, and cover the entire device part that comprises signal Processing substrate 21.For example, by screw shell is fixed to the first back barricade 33 and the second back barricade 34.In addition, can also require shell, the first back barricade 33 and the second back barricade 34 to be linked together, to strengthen its electrical connection by for example metal leaf springs (finger).In addition, be what to separate owing to connect substrate 23 with the preceding barricade 31 and the second back barricade 34, so the capacitive couplings between the wiring that connects substrate 23 and first barricade 31 and the second back barricade 34 becomes enough little.Thereby even when transmitting a large amount of high-frequency signals by the long line on the connection substrate 23 with limited wiring space, the leakage of radio-frequency signal also becomes quite little to preceding barricade 31 and secondary shielding plate 34.Therefore, can limit the unnecessary electromagnetic radiation that causes by the preceding barricade 31 that plays the antenna effect and the second back barricade 34.

Though do not describe the structure of first support component 41 and second support component 43 in detail, there is no particular limitation to its structure, do not make 23 distortion of connection substrate just passable as long as keep the distance between preceding barricade 31 and the secondary shielding plate 34.Fig. 6 A to Fig. 6 J shows the various examples of supporting part structure.Fig. 6 A, Fig. 6 B, Fig. 6 F and Fig. 6 G are planimetric maps, show four examples of supporting part structure pattern when watching connection substrate 23 from the P part side of Fig. 4 or Fig. 1 (for the ease of understanding, having removed preceding barricade 31).Fig. 6 C, Fig. 6 D, Fig. 6 E, Fig. 6 H, Fig. 6 I, Fig. 6 J are its cross-sectional views, have described the holding state of first support component 41 and second support component, 43 support and connection substrates 23.

In the example shown in Fig. 6 A, each of first support component 41 and second support component 43 all by two in fact the support member of the whole length of the long side of support and connection substrate 23 constitute, in the example shown in Fig. 6 B, constitute by the single support member in the whole zone of support and connection substrate 23.In the example shown in Fig. 6 F and Fig. 6 G, two support members shown in Fig. 6 A are divided into along a plurality of support members that are connected the long side direction of substrate 23 with the single support member shown in Fig. 6 B, so that it is for its opposed end,, that they are thinning thin at the longer side direction that they kept.

Will referring to Fig. 7 and Fig. 8 be described in according in the LCD of present embodiment to the restriction effect of unnecessary electromagnetic radiation.Fig. 7 is a curve map, shows the measurement result from the unnecessary electromagnetic radiation of the LCD of embodiment.Fig. 8 is a block scheme of measuring the measuring system of unnecessary electromagnetic radiation.

The structure of measuring system shown in Figure 8 is at first described.On the rotating disk of the LCD with shell 10 in personal computer (PC hereinafter referred to as) 61, keyboard 62 and mouse 63 etc. are installed in predetermined mask room 70 as shown in Figure 4.Measurement shows that from liquid crystal the antenna of the amount of electromagnetic radiation of device 10 is arranged between shielding house in 70 the position away from the measurement target on the rotating disk (being LCD 10) 3m.Usually measurement target is positioned at the center of rotating disk 73.Antenna 71 be arranged between shielding house 70 outer EMI receivers 76 and link to each other.The position of antenna 71 and rotating disk 73 is controlled by being arranged between shielding house 70 outer controllers 77, so that become 3m as the LCD 10 of measurement target and the distance between the antenna 71.In addition, in order to control whole measuring system, EMI receiver 76 and controller 77 be arranged between shielding house 70 outer control PC75 and link to each other.

Measure by using this measuring system.That is to say, disconnect the power supply of LCD 10, connect the power supply of PC61, keyboard 62 and mouse 63, make system be in common mode of operation.At this state, measure amount of electromagnetic radiation.Then, connect the power supply of LCD 10 and measure amount of electromagnetic radiation.The difference of the amount of electromagnetic radiation between measuring for the first time and measuring for the second time is exactly the amount of electromagnetic radiation from LCD 10.In scheduled frequency range, measure.In addition, measure the amount of electromagnetic radiation in the energy measurement LCD periphery when the height that in preset range, changes antenna 71 and when changing LCD 10 with respect to the angle of antenna 71 by rotation in succession.Fig. 7 is a curve map, show by change between the connection substrate 23 of LCD and the second back barricade 34 apart from d2, and in the scope from 30MHz to 1000MHz, change the measured result of frequency for each value of d2.Ordinate by the peak value of electromagnetic radiation represent the amount of electromagnetic radiation (noise level) of LCD 10, abscissa be illustrated in the second back barricade 34 and connect between the center line 28 of substrate 23 apart from d2.In addition, in this curve, the d2 that illustrates is and the ratio of the preceding barricade 31 and second distance L of back between the barricade 34.In this example, obtain the peak noise level (vertical polarization electromagnetic radiation) of 208MHz frequency.Referring to Fig. 7, noise level, both the peak value of unnecessary electromagnetic radiation in the frequency range from 30MHz to 1000MHz was minimum in distance range d2=(3/7) L to L/2.

Although described this embodiment as an example with LCD, the present invention is not limited thereto.In the display of for example flat-panel monitor and so on, as in the EL display etc., can obtain and above-mentioned effect similar effects, these displays have the structure of coming transmitting high-frequency signal by at the on-chip long transmission line of the connection with limited wiring space.

As noted earlier, because even display according to the present invention is when by when the on-chip long transmission line of the connection with limited wiring space comes transmitting high-frequency signal, also can limit from the unnecessary electromagnetic radiation that connects substrate, so have the advantage of the EMI that can limit display etc.

Claims

1, display comprises:

The display unit of a displayed image on the display unit front surface;

Signal processing unit is exported first signal that is used for displayed image by handling the outside picture intelligence of supplying with;

Driver element, response are exported the secondary signal that drives described display unit from first signal of described processing unit;

The linkage unit that described signal processing unit is connected with described display unit, described linkage unit comprises: be connected to first of described signal processing unit and flexibly connect part, that link to each other with described display unit and with described driver element mounted thereto second flexibly connect part, and be used to be connected described first and flexibly connect part and described second and flexibly connect partly the substrate sections that is connected;

Electric conductivity first screen unit has opening portion in the image displaying area territory of described display unit, is used for the side surface area in electromagnetic screen external zones and described image displaying area territory;

Electric conductivity secondary shielding unit, the whole rear side surface that is used for the described display unit of electromagnetic screen, and the support and connection substrate make its between described first screen unit and described secondary shielding unit respectively with the be separated by position of preset distance of described first screen unit and described secondary shielding unit.

2, display as claimed in claim 1, it is characterized in that, represent distance between described first screen unit and the secondary shielding unit by L, be illustrated in along the distance between the center of the thickness direction that connects substrate sections and described first screen unit with on the edge by d1 and d2 respectively and be connected the center of substrate sections thickness direction and the distance between the described secondary shielding unit, d1 and d2 satisfy following relation for L:

D1 〉=0.4 * L and d2 〉=0.4 * L.

3, display as claimed in claim 1, it is characterized in that also comprising first support component and second support component, first support component is used to support the part between described connection substrate sections and described first screen unit, second support component is used to support the part connecting between substrate sections and the secondary shielding unit, wherein with the described distance that is connected between substrate sections and described first screen unit, described first support component that distance between described connection substrate sections and the described secondary shielding unit is corresponding and the height of second support component are equal to each other.

4, display as claimed in claim 3 is characterized in that described first support component and described second support component made by non-conductive material.

5, display as claimed in claim 4 is characterized in that described non-conductive material is a silicon rubber.

6, display as claimed in claim 1 is characterized in that described display unit can be a LCD panel, it comprise the predetermined space of being separated by that be arranged in parallel two substrates, liquid crystal material layer is clipped between described two substrates.