Electro-optic device with folded interface substrate having folded projections with electronic parts

An electrooptic device is provided that comprises an electrooptic panel having an image display region for displaying an image and an interface substrate connected to the electrooptic panel via a connection part. The interface substrate has a folding part folded at the connection part toward a lower-surface side of the electrooptic panel and projections extending from the folding part positioned at the lower-surface side of the electrooptic panel. The projections are folded toward a top-surface side of the electrooptic panel so that electronic parts of the projections are opposed to driver ICs that are mounted on an overhanging part of the electrooptic panel.

RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2003-179591 filed Jun. 24, 2003 which is hereby expressly incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field of the Invention

The present invention relates to an electrooptic device, a method for manufacturing the same, and an electronic apparatus. More specifically, the present invention relates to an electrooptic device having electronic parts mounted on an interface substrate, the electronic parts being provided so as to face the top surface or lower surface of an electrooptic panel, a manufacturing method, and an electronic apparatus.

2. Related Art

A conventional electrooptic device such as a liquid-crystal display device comprises an electrooptic panel having an image display region including a plurality of pixels formed by a liquid crystal or the like, a driver circuit including a plurality of electronic parts required for driving the image display region, an interface substrate for connecting the electrooptic panel to an electronic apparatus such as a mobile phone, a light source for applying light to a light guide plate, and the light guide plate for emitting the light applied from the light source to the image display region. A backlight functioning as the light source is mounted on the interface substrate and provided in a case in which the electrooptic device is housed. The backlight applies light onto the light guide plate housed in the case, and the light guide plate emits light to the image display region of the electrooptic panel. Hitherto, hard substrates such as glass substrates have been used, as the interface substrate. Recently, however, flexible substrates that can be easily deformed and that have high versatility of design, such as FPCs (Flexible Printed Circuits), heat seals, and so forth, have been used.

The plurality of electronic parts forming the driver circuit includes a driver IC for supplying a driving voltage, a power-supply IC for supplying a voltage to the driver IC or the like, a control IC for controlling the driver IC and the power-supply IC. Of these electronic parts, the driver IC is mounted on the electrooptic panel and the other electronic parts (the power-supply IC, the control IC, and so forth) are mounted on the interface substrate. The other electronic parts are mounted near the light source mounted on the interface substrate.

However, the part on which the light source of the interface substrate is to be mounted is a limited space formed by the case and the light guide plate. Therefore, it is difficult to mount the above-described and the other electronic parts on this space. Conventionally, therefore, other electronic parts are mounted on a part of the interface substrate, where the part extends outside the electrooptic device. Therefore, the electrooptic device cannot be downsized. In the past, therefore, a technique for mounting the electronic parts such as the power IC and the control IC on the driver IC was proposed, where the driver IC is directly mounted on an overhanging part provided on the electrooptic panel including a pair of substrates that are opposed to each other.

According to this technique, a control-circuit substrate with the power-supply IC, the control IC, and so forth, that are mounted thereon is placed on the driver IC. Further, the control-circuit substrate and the driver IC are electrically connected to each other. However, according to the above-described known technique, the control-circuit substrate needs to be manufactured for each electrooptic panel with a different number of pixels or driver ICs mounted on overhanging parts at different positions. As a result, the number of procedures and the cost for manufacturing the electrooptic device increase. Further, the control-circuit substrate and the driver IC, or the electrooptic panel are connected by a number of wirings. In particular, where a plurality of the driver ICs are provided and electrically connected to the control-circuit substrate at one position, the area of the overhanging part with the driver ICs mounted thereon may increase, allowing for spaces among the wiring. As a result, the area of the control-circuit substrate may increase. Since the dimensions of the electrooptic device may increase, it may be difficult to downsize the entire electrooptic device. Further, since the control-circuit substrate is electrically connected only to the driver ICs, electronic parts other than those forming the driver circuit cannot be mounted on the control-circuit substrate.

Accordingly, an object of the present invention is to provide an electrooptic device that can be downsized and manufactured by reduced procedures and cost, a method for manufacturing the same, and an electronic apparatus.

SUMMARY

For achieving the above-described object, an electrooptic device according to one aspect comprises an electrooptic panel having an image display region for displaying an image and an interface substrate connected to the electrooptic panel via a connection part. The interface substrate has a folding part folded at the connection part toward a lower-surface side of the electrooptic panel and projections extending from the folding part positioned at the lower-surface side of the electrooptic panel. The projections are folded toward a top-surface side of the electrooptic panel so that electronic parts of the projections are opposed to the top surface of the electrooptic panel.

An electrooptic device according to another aspect comprises an electrooptic panel having an image display region for displaying an image and an interface substrate connected to the electrooptic panel via a connection part. The interface substrate has a folding part folded at the connection part toward a lower-surface side of the electrooptic panel and projections extending from the folding part positioned at the lower-surface side of the electrooptic panel. The projections are folded toward the lower-surface side of the electrooptic panel so that electronic parts of the projections are opposed to the lower surface of the electrooptic panel.

According to the above-described aspects, connection between the interface substrate and the electrooptic panel is achieved by using the connection part of the interface substrate, and the electronic parts are provided on the projections that are folded toward the top-surface side or lower-surface side of the electrooptic panel, whereby the electronic parts are opposed to the top surface or lower surface of the electrooptic panel. As a result, since the interface substrate does not need to be connected to the electrooptic panel, the projections may have any dimensions so long as the electronic parts can be mounted thereon. Therefore, the dimensions of the electrooptic device including the electrooptic panel and the interface substrate do not increase. Further, where the electronic parts of the projections are opposed to the top surface or lower surface of the electrooptic panel, or particularly where the electrooptic panel includes a pair of substrates and the electronic parts are opposed to an overhanging part provided between the substrates, the plurality of electronic parts can be provided on the top surface or lower surface of the electrooptic panel without increasing the thickness of the electrooptic device. Accordingly, the electrooptic device can be downsized. Further, where the connection part of the interface substrate can be connected to the electrooptic panel, the use of the single interface substrate is adequate, even though the pixel number and the positions of the mounted driver ICs are changed. As a result, it becomes unnecessary to manufacture the interface substrate for each electrooptic panel with different shapes (the pixel number and the position of the mounted driver ICs). As a result, the number of procedures and cost for manufacturing the electrooptic device are prevented from being increased.

Here, the electronic parts include not only electronic parts forming the driver circuit for driving the image display region of the electrooptic panel, that is, a driver IC for supplying a driving voltage to the image display region, a power-supply IC for supplying a voltage to the driver IC or the like, a control IC for controlling the driver IC and the power-supply IC, and so forth, but also other electronic parts. For example, where an LED functioning as a light source is mounted on the interface substrate, the other electronic parts include an electronic part for driving this LED and an electronic part required for an electronic apparatus having an electrooptic device including the interface substrate. Further, the electrooptic panel is formed as a hard substrate such as a glass substrate, or a flexible substrate such as an FPC (Flexible Printed Circuit) or a heat seal. The interface substrate is formed as the flexible substrate such as the FPC or the heat seal. Further, any light source can be used as the light source so long as it can be mounted on the interface substrate. Therefore, the light source includes the LED or an electro-luminescence device.

In an electrooptic device according to another aspect, the electrooptic panel has a driver IC mounted thereon for controlling image display of the image display region, and the projections are provided so as to face the driver IC.

According to this aspect, the electronic parts of the projections are opposed to the driver IC mounted on the electrooptic panel, whereby the electronic parts can be provided on the driver IC mounted on the electrooptic panel without increasing the thickness of the electrooptic device.

In an electrooptic device according to another aspect, the projections are provided on both sides of the interface substrate. According to this aspect, the plurality of projections is formed on the interface substrate so that the electronic parts are opposed to the top surface of the electrooptic panel. Therefore, compared to the case where the plurality of electronic parts is mounted on one projection, the number of wirings of the electronic parts formed on one of the projections becomes smaller, whereby the widths and dimensions of the projections can be reduced. As a result, it becomes possible to prevent the dimensions of the projections from being increased so as to become larger than those of the surface of the electrooptic panel. Particularly where the electrooptic panel is formed by the pair of substrates, the dimensions of the projections are prevented from being increased so as to become longer than those of the overhanging part provided between the pair of substrates. Therefore, the electrooptic device can further be downsized.

In an electrooptic device according to another aspect, the electronic parts include a power-supply IC for applying power at least to the image display region of the electrooptic panel. According to this aspect, the power-supply IC is mounted on the projection parts other than heat generation part of the interface substrate, such as a part on which the LED functioning as the light source is mounted. Therefore, it becomes possible to reduce malfunctions caused by heat in the power-supply IC including a temperature compensation circuit and irregular display of the image display region.

In an electrooptic device according to another aspect, the electronic parts are covered by an insulator layer. According to this aspect, the insulator layer is provided between the electronic parts of the projections and wiring formed on the top surface of the electrooptic panel, or the driver IC mounted thereon. As a result, it becomes possible to prevent the electronic parts of the projections from being electrically contacted with the wiring formed on the top surface of the electrooptic panel or the driver IC.

As a result, it becomes possible to further prevent irregular display of the image display region caused by shorting of the electronic parts of the projections, the wiring on the top surface of the electrooptic panel, and the driver IC.

In an electrooptic device according to another aspect, the electrooptic panel includes a pair of substrates with different dimensions and has an overhanging part formed by the pair of substrates, and the projections are provided so as to face the overhanging part. According to this aspect, the electronic parts of the projections are opposed to the overhanging part of the electrooptic panel, whereby the plurality of electronic parts can be provided on the top surface of the electrooptic panel without increasing the thickness of the electrooptic device.

As a result, the electrooptic device can be downsized.

In an electrooptic device according to another aspect, the driver IC is mounted on the overhanging part of the electrooptic panel, and the projections are fixed by fixing means so that a gap is provided between the electronic parts and the driver IC. According to this aspect, it becomes possible to prevent the electronic parts from being directly contacted with the driver IC by the gap formed between the electronic parts and the driver IC. As a result, irregular display of the image display region caused by shorting of the electronic parts or the driver IC can be reduced.

In an electrooptic device according to another aspect, the fixing means is a double-sided tape having an insulation characteristic and provided between opposing surfaces of the projections and the overhanging part. According to this aspect, the projections and the overhanging part are fixed to each other by using a double-sided tape with a predetermined height (thickness). Therefore, it becomes possible to form a gap with a predetermined height between the electronic parts and the driver IC by adjusting the height of the double-sided tape. As a result, the gap can be easily formed between the electronic parts and the driver IC, and positioning of the projections with reference to the overhanging part can be easily performed. Further, since the double-sided tape has the insulation characteristic, the wiring of the electronic parts or the like formed on the projections and that of the driver IC formed on the top surface of the electrooptic panel are not electrically contacted with each other. As a result, it becomes possible to reduce irregular display of the image display region caused by shorting of the wiring formed on the projections and the wiring formed on the top surface of the electrooptic panel.

In an electrooptic device according to another aspect, the fixing means is an adhesive having an insulation characteristic for fixing the electronic parts to the driver IC. According to this aspect, a gap is provided between the electronic parts and the driver IC by the adhesive having the insulation characteristic. Since the adhesive having the insulation characteristic exists between the electronic parts and the driver IC, the electronic parts are prevented from being directly contacted with the driver IC. As a result, it becomes possible to reduce irregular display of the image display region caused by shorting of the electronic parts, or the driver IC.

An electrooptic device according to another aspect further comprises a case having a housing for housing the electrooptic panel. A cutout part, where part of the projection folded toward the top-surface side of the electrooptic panel is placed, is provided on an inner-peripheral surface of the case. According to this aspect, each of the projections is inserted into the cutout part provided in the inner-peripheral surface of the case and folded toward the top-surface side of the electrooptic panel. As a result, the protrusions do not protrude outside the outer-peripheral surface of the case, whereby the electrooptic device can further be downsized. Further, it becomes possible to prevent the projections from being damaged and prevent the wiring thereof from being shorted out when the electrooptic panel is housed in the case, for example. As a result, irregular display of the image display region caused by shorting of the wiring of the projections can further be reduced.

An electrooptic device according to another aspect further comprises a light source provided on one of surfaces of the interface substrate and a light guide plate that is housed in the case and that receives light applied from the light source and emits the applied light onto the image display region. One end of a side face of the light guide plate has a curved face, where the one end is opposed to the cutout part. According to this aspect, the end of a side of the light guide plate, where the end is opposed to the cutout part where a folding part used for folding the protrusions toward the top-surface side of the electrooptic panel is placed, has the curved face. Therefore, since the folding part of the projection is folded along the curved face, the folding part of the projection is prevented from being bulged outward from the lower surface of the case. As a result, since the projections do not protrude outward from the lower surface of the case, the electrooptic device can further be downsized.

An electrooptic device according to another aspect further comprises a case having a housing for housing the electrooptic panel. A cutout part, where part of the projection folded toward the top-surface side of the electrooptic panel is placed, is provided on an outer-peripheral surface of the case. According to this aspect, the projection is inserted into the cutout part provided in the outer-peripheral surface of the case and folded toward the top-surface side of the electrooptic panel. As a result, the protrusions do not protrude from the outer-peripheral surface of the case, whereby the electrooptic device can further be downsized. Further, both ends of the cutout part of the case, where the folding part used for folding the projection toward the top-surface side of the electrooptic panel is placed at the cutout part, may preferably have a curved face. Since the folding part of the projection is folded along the curved face, the folding part of the projection is prevented from being bulged outward from the top surface or lower surface of the case.

Further, an electronic apparatus according to another aspect has the electrooptic device according to the present aspect, whereby the electrooptic device can be downsized. Therefore, the electronic apparatus can be downsized.

A method for manufacturing an electrooptic device according to another aspect comprises the steps of connecting an electrooptic panel having an image display region for displaying an image to a connection part of an interface substrate, folding a folding part of the interface substrate at the connection part toward a lower-surface side of the electrooptic panel, and folding projections extending from the folding part of the interface substrate toward a top-surface side of the electrooptic panel, so that electronic parts of the projections are opposed to the top surface of the electrooptic panel.

According to this aspect, connection between the interface substrate and the electrooptic panel is achieved by using the connection part of the interface substrate, and the electronic parts are provided on the projections that are folded toward the top-surface side of the electrooptic panel, whereby the electronic parts are opposed to the top surface of the electrooptic panel. As a result, since there is no need to use the projections for connecting the interface substrate to the electrooptic panel, the projections may have any dimensions so long as the electronic parts can be mounted thereon. Therefore, the dimensions of the electrooptic device do not increase. Further, where the electronic parts of the projections are opposed to the top surface of the electrooptic panel, or particularly where the electrooptic panel includes a pair of substrates and the electronic parts are opposed to an overhanging part provided between the substrates, the plurality of electronic parts can be provided on the top surface of the electrooptic panel without increasing the thickness of the electrooptic device.

Accordingly, the electrooptic device can be downsized. Further, where the connection part of the interface substrate can be connected to the electrooptic panel, the use of the single interface substrate is adequate, even though the pixel number and the positions of the driver ICs mounted on the overhanging part are changed. As a result, it becomes unnecessary to manufacture the interface substrate for each of electrooptic panels with different shapes (the pixel number and the position of the mounted driver ICs). As a result, the number of procedures and cost for manufacturing the electrooptic device are prevented from being increased.

A method for manufacturing an electrooptic device according to another aspect comprises the steps of connecting an electrooptic panel having an image display region for displaying an image to a connection part of an interface substrate having a light source mounted thereon, housing a light guide plate in a case, inserting a projection extending from a folding part of the interface substrate between a cutout part provided on an inner-peripheral surface of the case and the light guide plate, fixing the interface substrate to the light guide plate so that light emitted from the light source is incident on the light guide plate, housing the electrooptic panel in a housing formed in the case by folding the electrooptic panel at the folding part, folding the projection toward a top-surface side of the electrooptic panel, and providing electronic parts of the projection, so as to be opposed to the top surface of the electrooptic panel.

According to this aspect, connection between the interface substrate and the electrooptic panel is achieved by using the connection part of the interface substrate and the plurality of electronic parts are provided on the projections that are folded toward the top-surface side of the electrooptic panel, whereby the electronic parts are opposed to the top surface of the electrooptic panel. As a result, since the interface substrate does not need to be connected to the electrooptic panel, the projections may have any dimensions so long as the electronic parts can be mounted thereon. Therefore, the dimensions of the electrooptic device do not increase. Further, where the electronic parts of the projections are opposed to the overhanging part of the top surface of the electrooptic panel, the thickness of the electrooptic device can be decreased. Accordingly, the electrooptic device can be downsized.

Further, since the electrooptic device is assembled (manufactured) by inserting the projection of the interface substrate into the cutout part, it becomes possible to prevent the projection from being damaged and the wiring of the projection from being shorted out when the electrooptic panel is housed in the case. As a result, irregular display of the image display region caused by shorting of the wiring of the projection can be reduced.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described in detail with reference to the attached drawings. It should be noted that the present invention is not limited to these embodiments. An electrooptic device according to the present invention may be, for example, a liquid-crystal display, but is not limited thereto.

First Embodiment

FIGS. 1 and 2illustrate an exemplary electrooptic panel and an exemplary interface substrate. As shown in these drawings, an electrooptic panel10and an interface substrate20are mounted on an electronic apparatus such as a mobile phone. The electrooptic panel10is a hard substrate such as a glass substrate and has an image display region11. This image display region11includes a plurality of pixels. Where the electrooptic device is a liquid-crystal display, for example, the electrooptic panel10has two substrates including a first electrooptic panel10aand a second electrooptic panel10b. A liquid crystal is filled between these two substrates by using a sealing material (not shown). Further, polarization plates12and13are provided on and under the image display region11, so as to polarize light of LEDs27of a light source26that will be described later.

The first electrooptic panel10ais longer than the second electrooptic panel10bin the longitudinal direction, whereby an overhanging part14is formed. This overhanging part14has driver ICs15to17mounted thereon. The driver ICs15to17form a driver circuit for driving the image display region11. Input terminals (not shown) of the driver ICs15to17are electrically connected to wiring of the driver ICs15to17formed on the overhanging section14of the electrooptic panel10via an AFC (Anisotropic Conductive Film). That is to say, this electrooptic device has a COG (Chip On Glass) configuration. The driver ICs15and17form a scan-signal driver circuit and the driver IC16forms a data-signal driver circuit.

The interface substrate20is a flexible substrate such as an FPC, a heat seal, and so forth. This interface substrate20includes a folding part21, a connection part22, two projections23and24, and an external connection part25. The folding part21is substantially rectangular-shaped and the connection part22is formed on its end. A plurality of LEDs (Light Emitting Diode)27(three LEDs are shown inFIG. 1) is mounted on the folding part21, as the light source26. The light source26is provided between a light guide plate31and a case32of a light guide unit30that will be described later. The LEDs27apply light on the light guide plate31of the case32. The connection part22is electrically connected to the overhanging part14of the electrooptic panel10. That is to say, wiring of a power IC28aand control ICs (other electronic parts28b) of electronic parts28mounted on the projections23and24that will be described later, the wiring extending to the connection part22, is electrically connected to wiring (not shown) of the driver ICs15to17formed on the overhanging part14of the electrooptic panel10via an AFC (Anisotropic Conductive Film).

The two projections23and24project outside the width W of the electrooptic panel10to which the connection part22of the interface substrate20is connected. The projections23and24include band-shaped electronic-part mounting sections23aand24a, and band-shaped arms23band24bfor electrically connecting the electronic-part mounting sections23aand24ato the both sides of the folding part21. A plurality of electronic parts28is mounted on one face of each of the electronic-part mounting sections23aand24aof the projections23and24. The electronic parts28include, for example, a power-supply IC28afor supplying a voltage to the driver ICs15to17mounted on the electrooptic panel10and other electronic part28bsuch as a control IC for controlling the driver ICs15to17and the power-supply IC28a, and an electronic part required for an electronic apparatus on which the electrooptic device is mounted. These electronic parts28are electrically connected to wiring formed on one face of each of the projections23and24. This electrical connection can be achieved by using the above-described AFC. Here, the power-supply IC28ais mounted on the projection23. The projection part23is a part other than the light source26of the interface substrate20, where the light source26is a heat-generation part. As a result, it becomes possible to reduce malfunctions in a temperature compensation circuit of the power-supply IC28aand irregular display of the image display region11of the electrooptic panel10.

The wiring of the electronic parts28on the projection23and that of the electronic parts28on the projection24extend to the folding part21via the arms23band24b, respectively. Further, the wiring of the power-supply IC28aand that of the control IC, which is the other electronic part28b, extend to the connection part22of the folding part21and is electrically connected to the wiring of the driver ICs15to17. On the other hand, the wiring of the other electronic part28b, that is, the electronic part required for the electronic apparatus extends from the folding part21to the external connection part25and is electrically connected to the electronic apparatus. That is to say, the power-supply IC28athat is electrically connected only to the driver ICs and the other electronic part, that is, an electronic part other than the control IC can be mounted on the projections23and24.

FIG. 3illustrates an example light guide unit according to the present invention.FIG. 3(a) is an exploded perspective view of the light guide unit,FIG. 3(b) illustrates section A—A ofFIG. 3(a), andFIG. 3(c) illustrates section B—B ofFIG. 3(a). As shown in this drawing, a light guide unit30includes the light guide plate31, the case32, a reflection sheet33, a diffusion sheet34, and two prism sheets35.

This light guide unit30applies light from the LEDs27of the light source26of the interface substrate20onto the image display region11of the electrooptic panel10. The light guide unit30and the light source26form an illumination device for applying light onto the image display region11of the electrooptic panel10.

The light guide plate31is formed as a rectangular-shaped transparent synthetic resin. A plurality of retaining parts31a(four retaining parts are shown inFIG. 3(a)) are provided on predetermined positions on both sides of the light guide plate31. Further, two protruding parts31band31care provided on one of four sides of the light guide plate31, so as to project therefrom. The light source26of the interface substrate20is provided between these two protruding parts31band31c. Here, as shown inFIG. 3(b), one end (a lower end in this drawing) of a side of each of the protruding parts31band31cof the light guide plate31is a curved face31d.

The case32is formed as a heat-shaped plastic and includes a housing32afor housing the electrooptic panel10and a light-guide-plate housing32bfor housing the light guide plate31. A plurality of retaining holes32c(Four retaining holes are shown inFIG. 3(a).) is formed on predetermined parts of predetermined sides of a light-guide-plate housing32b, the predetermined parts corresponding to the retaining parts31aof the light guide plate31. Further, cutout parts32dand32eare formed, so as to be opposite to each other, on one side of the housing32aand one side of the light-guide-plate housing32b, as shown inFIG. 3(c). That is to say, the cutout parts32dand32eare formed on the inner-peripheral surface of the case32. The width of each of the cutout parts32dand32eis longer than the thickness of the interface substrate20.

The reflection sheet33is provided on the lower surface of the light guide plate31and reflects light emitted from the lower surface of the light guide plate31of light that is emitted from the light source26and guided to the light guide plate31toward the top-surface side of the light guide plate31. The diffusion sheet34is provided on the top surface of the light guide plate31and diffuses light incident from the top surface of the light guide plate31so that uniform light is emitted from the surface. The two prism sheets35are stacked on the surface of the diffusion sheet34and used for increasing the brightness of light emitted from the diffusion sheet34and applying the light onto the image display region11of the electrooptic panel10.

Reference numeral40indicates a light shielding plate for fixing the electrooptic panel10to the light guide unit30. The light shielding plate40is formed as a frame-shaped synthetic resin and has a light-shielding characteristic.

A protruding part41extends from one of four sides of the light shielding plate40in a longitudinal direction of the light shielding plate40, so as not to cover the cutout part32eof the light-guide-plate housing32bof the case32. An adhesive is applied on both surfaces of the light shielding plate40.

Next, a manufacturing method (assembly method) used for the electrooptic device according to the first embodiment will now be described, where the electrooptic device includes the electrooptic panel10, the interface substrate20, and the light guide unit30.FIG. 4shows the assembly flow of the electrooptic device1according to the first embodiment.FIGS. 5 to 9illustrate how the electrooptic device is assembled. First, the electrooptic panel10and the interface substrate20are connected to each other (step ST1), as shown inFIG. 4. That is to say, the connection part22of the interface substrate20is electrically connected to the overhanging part14of the electrooptic panel10.

Then, the light guide plate31is housed in the case32(step ST2). As shown inFIG. 5(a), the light guide plate31is housed in the light-guide-plate housing32bof the case32from the lower side of the case32. At this time, the retaining parts31aof the light guide plate31are inserted into retaining holes32cof the case32and retained. Then, the reflection sheet33is placed on the lower surface of the light guide plate31, so as to cover the lower side of the case32housing the light guide plate31, as shown inFIG. 5(b). At this time, the cutout parts32eof the case32are exposed at the lower side of the case32without being blocked by the reflection sheet33. Further, the diffusion sheet34and the two prism sheets35are sequentially provided on the top surface of the light guide plate31housed in the light-guide-plate housing32bof the case32, whereby the light guide unit30is assembled, as shown inFIG. 6(a). Further, the light shielding plate40is placed on the base of the housing32aof the case32, as shown inFIG. 6(b). At this time, the top surface of the light guide unit30, that is, the top surface of the prism sheet35provided on the light guide plate31is enclosed with the light shielding plate40. Further, the cutout parts32eof the case32are exposed due to the protruding part41without being blocked by the light shielding plate40.

Then, the two projections23and24of the interface substrate20are inserted between the cutout parts32eof the case32and the protruding parts31band31cof the light guide plate31, respectively (step ST3). First, the interface substrate20is positioned so that the lower surface of the case32and that of the electrooptic panel10are opposed to each other, as shown inFIG. 7. Then, the two projections23and24of this interface substrate20are folded in the direction of arrow C so that the two projections23and24are oriented in the lower side of the case32, that is, the cutout parts32eof the case32. Then, the electrooptic panel10and the interface substrate20are moved toward the lower side of the case32, where the projections23and24are folded, and the projections23and24are inserted between the cutout parts32eof the case32and the protruding parts31band31cof the light guide plate31, respectively, as shown by arrows D.

Then, the projections23and24of the interface substrate20are folded toward the top-surface side of the electrooptic panel10(step ST6). That is to say, the projections23and24exposed from the cutout parts32dof the case32, that is, electronic-part mounting parts23aand24aare folded in the direction of arrow F, as shown inFIG. 9(a). Next, the plurality of electronic parts28of the projections23and24are provided, so as to face the driver ICs15to17(step ST7). That is to say, the projections23and24of the interface substrate20are provided so as to face the top surface of the electrooptic panel10. More specifically, one of faces of a double-sided tape50functioning as fixing means, the double-sided tape50having an insulation characteristic of a predetermined height (thickness), is fixed to the overhanging part14of the electrooptic panel10beforehand. Then, where the projections23and24are folded toward the top-surface side of the electrooptic panel10at the above-described step ST6, the other surface of the double-sided tape50is fixed to the surfaces (the surfaces on which the plurality of electronic parts28is mounted) of the projections23and24facing the surface of the electrooptic panel10. Here, the height of the double-sided tape50is adjusted, so that the projections23and24folded toward the top-surface side of the electrooptic panel10are not provided above the electrooptic panel10. Further, a gap that will be described later is formed between the plurality of electronic parts28and the driver ICs15to17. That is to say, the gap can be easily formed between the electronic parts28and the driver ICs15to17by adjusting the height of the double-sided tape50, and the positions of the projections23and24with reference to the overhanging part14of the electrooptic panel10can be easily determined. Subsequently, the manufacturing (assembly) of the electrooptic device1is finished.

As has been described, the interface substrate20is folded at the connection part22toward the lower-surface side of the electrooptic panel10and the projections23and24are folded toward the top-surface side of the electrooptic panel10, whereby the electronic parts28(28aand28b) of the projections23and24are opposed to the top-surface of the electrooptic panel10. That is to say, the connection between the electrooptic panel10and the interface substrate20is achieved by using the connection part22of the interface substrate20, and the plurality of electronic parts28are provided on the projections that are folded toward the top-surface side of the electrooptic panel10, whereby the electronic parts28are opposed to the top surface of the electrooptic panel10. As a result, since the electrooptic panel10does not need to be connected to the interface substrate20, the projections23and24can be of any shape, so long as the plurality of electronic parts28is mounted thereon. Therefore, the dimensions of the electrooptic device1do not increase. Further, since the plurality of electronic parts28is opposed to the overhanging part14of the top-surface of the electrooptic panel10, the plurality of electronic parts28can be provided on the top-surface of the electrooptic panel10without increasing the thickness of the electrooptic device1. As a result, the electrooptic device1can be downsized.

Where the connection part22of the interface substrate20can be connected to the electrooptic panel10, the use of the single interface substrate20would be adequate, even though the number of pixels or the position of the driver ICs15to17are changed. As a result, it becomes unnecessary to manufacture the interface substrate20for each case where the shape (the number of pixels and the position of the driver ICs15to17) of the electrooptic panel10is changed. As a result, the number of procedures and the cost for manufacturing the electrooptic device1are prevented from being increased.

Further, the interface substrate20has the two projections23and24so as to make the plurality of electronic parts28face the surface of the electrooptic panel10. As a result, the wiring of the electronic parts28formed on one of the projections becomes less than that of the case where the plurality of electronic parts28is mounted on one projection, whereby the widths and dimensions of the projections can be reduced. As a result, it becomes possible to prevent the dimensions of the projections from being increased so as to be larger than those of the overhanging part14on the surface of the electrooptic panel10. Therefore, the electrooptic device1can further be downsized.

FIG. 10is a sectional view of the electrooptic device according to the first embodiment.FIG. 10(a) is a main-part longitudinal-sectional view,FIG. 10(b) is a main-part cross-sectional view, andFIG. 10(c) is an enlarged view of G part shown inFIG. 10(b). The assembled electrooptic device1has arms23band24bthat are part of the projections23and24, as shown inFIGS. 10(a) and10(b). The arms23band24bextend from the lower surface of the case32and between the sides of the protruding parts31band31cof the light guide plate31and the cutout parts32eof the case32. The arms23band24bfurther extend between the sides of the electrooptic panel10and the cutout parts32dof the case32. Then, the arms23band24bare drawn out to the top-surface side of the electrooptic panel10. That is to say, parts of the projections23and24are inserted into the cutout parts32dand32eformed on the inner-peripheral surface of the case32, and folded toward the display side of the electrooptic panel10. Therefore, the protrusions23and24do not protrude outside the outer-peripheral surface of the electrooptic device1(the case32), whereby the electrooptic device1can further be downsized. Further, it becomes possible to prevent the projections23and24from being damaged and the wiring thereof from being shorted out during the electrooptic panel10is housed in the case32, for example. As a result, irregular display of the image display region11of the electrooptic panel10of the electrooptic device1can be reduced.

Further, as shown inFIG. 10(c), the projections23and24are fixed by using the double-sided tape50functioning as the fixing means so that gap H is formed between the plurality of electronic parts28(28aand28b) and the driver ICs15to17. Therefore, this gap H reduces the shortings caused by direct contact between the plurality of electronic parts28and the driver ICs15to17. Further, since this double-sided tape50has an insulating characteristic, it can reduce shortings caused by electrical contact between the wiring of the plurality of electronic parts28formed on the projections23and24and that of the driver ICs15to17formed on the overhanging part14that is the top surface of the electrooptic panel10. As a result, irregular display of the image display region11of the electrooptic panel10of the electrooptic device1can be reduced.

Further, as shown inFIG. 10(b), an end of the side of each of the protruding parts31band31cof the light guide plate31, the protruding parts31band31cbeing opposed to the cutout parts32eof the case32, is formed as the curved face31d. Therefore, folding parts I used for folding the projections23and24toward the top-surface side of the electrooptic panel10are folded along the curved faces31d. That is to say, the folding parts I of the projections23and24are prevented from being bulged outward from the lower surface of the electrooptic device1(the case32). Since the projections23and24do not project outward from the lower surface of the electrooptic device1(the lower surface of the case32), the electrooptic device1can further be downsized.

Second Embodiment

FIG. 11illustrates another example case according to the present invention.FIG. 12illustrates an example electrooptic device according to a second embodiment. An electrooptic device1′ shown inFIG. 12is different from the electrooptic device1shown inFIG. 9(b) in that the projections23and24are folded toward the top-surface side of the electrooptic panel10via cutout parts32fprovided on the outer-peripheral surface of a case32′. Further, the basic configuration of the electrooptic device1′ except the electrooptic panel10, the interface substrate20, and the case32′ of the light guide unit30is substantially the same as that of the electrooptic device1shown inFIG. 9(b). Therefore, the description of the electrooptic device1′ is omitted. Here, the electrooptic device1′ has the COG configuration, as is the case with the electrooptic device1shown inFIG. 9(b).

The case32′ is formed as a heat-shaped plastic and includes the housing32afor housing the electrooptic panel10and the light-guide-plate housing32bfor housing the light guide plate31, as shown inFIG. 11. The plurality of retaining holes32c(Four retaining holes are shown in this drawing) is formed on predetermined sides of the light-guide-plate housing32bat predetermined positions corresponding to the retaining parts31aof the light guide plate31. Further, the cutout parts32fare formed, so as to be opposite to each other, on the outer-peripheral surface of the case32, as shown inFIG. 11(c). The width of each of the cutout parts32fis longer than the thickness of the interface substrate20.

Next, a manufacturing method (an assembly method) for the electrooptic device1′ will be described.FIG. 13illustrates the assembly flow of the electrooptic device1′. First, as shown inFIG. 13, the electrooptic panel10and the interface substrate20are connected to each other (step ST11), as shown inFIG. 13. That is to say, the connection part22of the interface substrate20is electrically connected to the overhanging part14of the electrooptic panel10. Then, the light guide plate31is housed in the case32′ (step ST12). That is to say, the light guide plate31is housed in the light-guide-plate housing32bof the case32′ from the lower side of the case32′ (refer toFIG. 5(a)). At this time, the retaining parts31aof the light guide plate31are inserted into the retaining holes32cof the case32′ and retained.  Then, the reflection sheet33is placed on the lower surface of the light guide plate31, so as to cover the lower surface of the case32′ housing the light guide plate31(refer toFIG. 5(b)). Further, the diffusion sheet34and the two prism sheets35are sequentially provided on the top surface of the light guide plate31housed in the light-guide-plate housing32bof the case32′, whereby the light guide unit30is assembled (refer toFIG. 6(a)). Further, the light shielding plate40is placed on the base of the housing32aof the case32′ (refer toFIG. 6(b)).

Next, the electrooptic panel10is housed in the housing32aof the case32′ (step ST13). That is to say, the lower surface (the polarizing plate13) of the electrooptic panel10is fixed by the above-described light shielding plate40, whereby the electrooptic panel10and the light guide unit30are integrated with each other. Subsequently, the LEDs27of the light source26are provided between the light guide plate31, the case32′, and the electrooptic panel10. Then, the interface substrate20is fixed to the light guide plate31, where the electrooptic panel10is housed in the housing32aof the case32′ (step ST14). That is to say, the interface substrate20is folded at the connection part22toward the lower-surface side of the electrooptic panel10, and the folding part21of the interface substrate20and the lower surface of the light guide plate31are fixed to each other by using an adhesive or a double-sided tape (not shown).

Then, the projections23and24of the interface substrate20are folded toward the top-surface side of the electrooptic panel10(step ST15). That is to say, the projections23and24are folded from the outer-peripheral surface of the case32′ toward the top-surface side of the optoelectronic panel10, as shown inFIG. 12(a). Here, predetermined parts of the projections23and24are inserted into the cutout parts32fprovided on the outer-peripheral surface of the case32′. Next, the plurality of electronic parts28of the projections23and24are provided, so as to be opposed to the driver ICs15to17(step ST16). That is to say, the projections23and24of the interface substrate20are provided, so as to be opposed to the top surface of the electrooptic panel10. This configuration is achieved by fixing the overhanging part14of the top surface of the electrooptic panel10to the surfaces of the projections23and24(the surfaces on which the plurality of electronic parts28are mounted), the surfaces facing the surface of the electrooptic panel10, by using the double-sided tape50functioning as the fixing means, as shown in this drawing. Subsequently, the manufacturing (assembly) of the electrooptic device1′ is finished.

As has been described, the interface substrate20is folded at the connection part22toward the lower-surface side of the electrooptic panel10and the projections23and24are folded toward the top-surface side of the electrooptic panel10, whereby the electronic parts28(28aand28b) of the projections23and24are opposed to the surface of the electrooptic panel10. That is to say, the connection between the electrooptic panel10and the interface substrate20is achieved by using the connection part22of the interface substrate20, and the plurality of electronic parts28are provided on the projections that are folded toward the top-surface side of the electrooptic panel10, whereby the electronic parts28are opposed to the top surface of the electrooptic panel10. As a result, since the electrooptic panel10does not need to be connected to the interface substrate20, the projections23and24may be of any shape, as long as the plurality of electronic parts28can be mounted thereon. Therefore, the dimensions of the electrooptic device1′ do not increase. Further, since the plurality of electronic parts28are opposed to the overhanging part14of the top surface of the electrooptic panel10, it becomes possible to provide the plurality of electronic parts28on the top surface of the electrooptic panel10without increasing the thickness of the electrooptic device1′. As a result, the electrooptic device1′ can be downsized.

Further, as shown inFIG. 12(b), the arms23band24bthat are parts of the projections23and24extend from the lower surface of the case32′, go through the cutout parts32fof the case32′, and are drawn out to the top-surface side of the electrooptic panel10. That is to say, parts of the projections23and24are inserted into the cutout parts32fformed on the outer-peripheral surface of the case32′, and folded toward the display side of the electrooptic panel10. Therefore, the protrusions23and24do not protrude outside the outer-peripheral surface of the electrooptic device1′ (the case32′), whereby the electrooptic device1′ can further be downsized.

The plurality of electronic parts28of the above-described embodiment can be covered by an insulator layer. In this case, the electronic parts28of the projections23and24are prevented from being electrically contacted with the wiring on the top surface of the electrooptic panel10and the driver ICs15to17.

As a result, it becomes possible to prevent the electronic parts28of the projections23and24, the wiring on the surface of the electrooptic panel10, and the driver ICs15to17from being shorted out. Further, irregular display of the image display region11of the electrooptic panel10is reduced.

In the above-described embodiment, the double-sided tape is used as the fixing means for fixing the projections23and24to the top surface of the electrooptic panel10. However, another means can be used where the gap H is formed between the electronic parts28of the projections23and24, and the driver ICs15to17of the electrooptic panel10. For example, the electronic parts28of the projections23and24may be fixed to the driver ICs15to17of the electrooptic panel10by using an insulating adhesive so that the projections23and24are fixed to the top surface of the electrooptic panel10. In this case, the insulating adhesive provided between the electronic parts28and the driver ICs15to17functions as a gap, whereby the electronic parts28and the driver ICs15to17are prevented from being directly contacted with each other. As a result, it becomes possible to reduce irregular display of the image display region caused by shortings of the electronic parts28, or the driver ICs15to17.

In the case where the projections23and24are prevented from being moved to the other side of the top surface of the electrooptic panel10through the use of a metal frame for holding the electrooptic devices1and1′, a gap may be provided between the electronic parts28of the projections23and24, and the driver ICs15to17of the electrooptic panel10. Further, the gap may be formed between the electronic parts28of the projections23and24, and the driver ICs15to17of the electrooptic panel10by forming a T-shaped retaining piece, for example, on one of the projections23and24, and a retaining hole on the other. This retaining piece is inserted into the retaining hole so that the projections23and24are retained to each other.

According to the above-described embodiment, the projections23and24of the interface substrate20project from both sides of the holding part21of the interface substrate20. However, the present invention is not limited to the above-described configuration.FIGS. 14 and 15illustrate other example interface substrates. As shown inFIG. 14, a projection23′ may project from one of sides of the folding part21of an interface substrate20′. In this case, length L of the projection23′ may preferably be determined so that the entire electronic parts28can be provided on the projections23′. The projections23and23′, and24only have to project outward from the width W of the electrooptic panel10to which the connection part22of the interface substrates20or20′ is connected. Further, an electronic-part mounting part23′aof the projection23′ may be connected to an arm23′cprojecting from the folding part21of the interface substrate20′ in a direction with a predetermined inclination, as shown inFIG. 15. In this case, the interface substrate20′ is folded at the connection part22toward the lower-surface side of the electrooptic panel10, and the arm23′cis folded back along the folding part21of the folded interface substrate20′. Subsequently, the projection23′ is folded toward the top-surface side of the electrooptic panel10, so that the plurality of electronic parts28of the projection23′ is opposed to the surface of the electrooptic panel10.

Although the electrooptic device having the COG configuration has been described, as the electrooptic devices1and1′, the present invention is not limited to the above-described embodiments, and can be used for an electrooptic device having a COF (Chip On FPC) configuration, wherein the driver ICs15to17are mounted on the interface substrate20.

Further, the liquid-crystal display has been described in the above-described embodiments, as the electrooptic devices1and1′. However, the present invention is not limited to the above-described embodiments, and can be used for an electrophoretic device, for example. That is to say, the present invention can be used for various electrooptic devices using externally applied light.

Application of the Present Invention

An electronic apparatus having the electrooptic device1or1′ of the present invention mounted thereon may be, among others, a mobile phone, or an apparatus using the electrooptic device, where the apparatus includes, for example, a mobile information apparatus referred to as a PDA (Personal Digital Assistants), a mobile personal computer, a personal computer, a digital still camera, an on-vehicle monitor, a digital video camera, a liquid-crystal television, a video tape recorder of view-finder type or monitor-direct-view type, a car navigation system, a pager, an electronic personal organizer, an electronic calculator, a word processor, a work station, a video phone, a POS terminal, and so forth.

The electrooptic devices1and1′ of the present invention may be either a semi-transmission liquid-crystal display device or a liquid-crystal display device of full-transmission type or full-reflection type. Where the full-reflection-type liquid crystal display is used, the light source26and the light guide unit30of the interface substrate20for applying light onto the image display region11of the electrooptic panel10may not be provided.

The sounder-equipped electrooptic devices1and1′ of the present invention may be a active-matrix-type liquid-crystal display (e.g., a liquid-crystal display having a thin-film transistor (TFT), or a thin-film diode (TFD) functioning as a switching element) or a passive-matrix liquid-crystal display. Further, the electrooptic devices1and1′ of the present invention are not limited to the liquid-crystal display, but may be an electro-luminescence device, a plasma display device, a field-emission display device, an LED (light emitting diode) display device, an electrophoretic display device, and so forth. Further, where a self-luminous electrooptic device is used, the light source26and the light guide unit30of the interface substrate20for applying light onto the image display region11of the electrooptic panel10may not be provided.