JP2001126520A - Light source substrate for illumination and liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source substrate for illumination having a reduced thickness, and a liquid crystal device. SOLUTION: The light source substrate 41 for illumination has a light emitting element substrate 6 on which a light-emitting element 31 is mounted; and a support substrate 7 to which the light emitting element substrate 31 is connected. The light emitting element substrate 6 is attached in such a manner that it protrudes in a thickness direction Z-Z of the support substrate 7. The light source substrate 41 for illumination is formed by connecting the light emitting element substrate 6 attached with a concave portion 37 and the support substrate 7 attached with convex portion 7 to each other. Both substrates 6 and 7 are attached to each other by connection of the concave portion 37 and the convex portion 38, thereby allowing a dimension in the thickness direction Z-Z to be significantly reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination light source substrate having a light emitting element and a liquid crystal device using the same.

[0002]

2. Description of the Related Art Electro-optical devices that perform a predetermined operation using light include, for example, a liquid crystal device, an optical device using an electroluminescence (EL) element, a plasma display (PDP), and a field emission element (FED). Various devices such as an optical device used are conventionally known.

When a liquid crystal device is considered as the electro-optical device, the liquid crystal device controls the voltage applied to the liquid crystal to control the orientation of the liquid crystal, thereby modulating the light passing through the liquid crystal, thereby forming a character. , Numbers, figures, etc. are displayed. Conventionally, as this liquid crystal device, for example, FIG.
One using an illumination light source substrate 51 shown in FIG.

The conventional light source substrate 51 for illumination is formed by mounting an LED (Light Emitting Diode) 52 as a light emitting element on a light emitting element substrate 53 and connecting the light emitting element substrate 53 to a support substrate 54. Support substrate 5
4 is configured as, for example, a control board on which various control circuits are mounted. When the illumination light source substrate 51 is incorporated in a liquid crystal device, as shown in FIG.
The light emitting surface of 52 is arranged at a position facing the light receiving surface of the light guide 56.

In the liquid crystal device using the illumination light source substrate 51, light from the LED 52 is taken into the light guide 56,
Further, light R of uniform intensity is emitted from the light emission surface,
This uniform light is supplied to a liquid crystal panel (not shown) and used for displaying a visible image such as a character.

[0006]

However, in the conventional illumination light source substrate 51, the light emitting element substrate 53 is simply connected in the thickness direction of the support substrate 54, that is, in the ZZ direction without any contrivance. Was just being. For this reason, the conventional illumination light source substrate 51 has a thickness direction ZZ
Therefore, there is a problem that the size of the liquid crystal device using the same is also large.

The present invention has been made in view of the above problems, and has as its object to provide an illumination light source substrate and a liquid crystal device having a small dimension in the thickness direction.

[0008]

(1) In order to achieve the above object, an illumination light source substrate according to the present invention comprises a light emitting element substrate on which a light emitting element is mounted and a support to which the light emitting element substrate is connected. A light-emitting element substrate, wherein the light-emitting element substrate is provided with a concave portion on the light-emitting element substrate, a convex portion on the support substrate, The light emitting element substrate and the support substrate are connected to each other in a state where the protrusion of the support substrate is fitted in the recess.

According to this light source substrate for illumination, the light emitting element substrate and the supporting substrate are not simply superposed and connected, but the concave portion provided on the light emitting element substrate and the convex portion provided on the supporting substrate are fitted. Since the two are connected in this state, the dimension in the thickness direction can be reduced, that is, the overall shape can be reduced.

[0010] Further, since the light emitting element substrate can be pressed by the convex portion of the support substrate, it is possible to prevent the light emitting element from being displaced for a long time. further,
By fitting the concave portion of the light emitting element substrate and the convex portion of the support substrate,
Since both substrates can be directly positioned with respect to each other, a soldering process or the like for connecting both substrates can be performed accurately and quickly.

(2) In the illumination light source substrate according to the above (1), a plurality of the light emitting elements can be provided on the light emitting element substrate. In this case, the concave portion is formed by the adjacent light emitting element. It is desirable to be formed between them. In this case, the thickness can be further reduced.

(3) In the illumination light source substrate according to the above item (1) or (2), it is preferable that the light emitting element is accommodated in an opening formed beside a convex portion of the support substrate. In this case, the thickness can be further reduced.

(4) Next, the liquid crystal device according to the present invention comprises:
A liquid crystal panel in which liquid crystal is sealed between a pair of substrates, a light emitting element substrate on which a light emitting element is mounted, a support substrate to which the light emitting element substrate is connected, and guiding light from the light emitting element to the liquid crystal panel In a liquid crystal device having a light guide, the light emitting element substrate is provided with a concave portion, the support substrate is provided with a convex portion, and the light emission is performed in a state where the convex portion of the support substrate is fitted into the concave portion of the light emitting element substrate. The device substrate and the supporting substrate are connected to each other.

According to this liquid crystal device, the light emitting element substrate and the supporting substrate are not simply overlapped and connected, but the concave portion provided on the light emitting element substrate and the convex portion provided on the supporting substrate are fitted. Because we connected both in the state,
The dimension in the thickness direction of the illumination light source substrate including the light emitting element substrate and the support substrate can be reduced, and as a result, the thickness of the overall shape of the liquid crystal device can be reduced.

(5) In the liquid crystal device according to the above (4), the connection between the light emitting element substrate and the support substrate is closed so as to close the openings formed on both sides of the convex portion of the support substrate. It is desirable to provide a shielding member on a portion of the portion opposite to the side on which the light guide is provided.

In the case where a structure for accommodating an LED by an opening formed in the control board in order to reduce the thickness is adopted, there is a possibility that flux, dust and the like may enter the liquid crystal panel through this opening. . Before connecting the TCP to the internal area terminal of the control board, if a shielding tape is attached to the connection portion between the LED board and the control board so as to cover the opening, it is possible to use such a flux or dust to the liquid crystal panel. Can be prevented from entering.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example in which an illumination light source substrate according to the present invention is used as a light source of a liquid crystal device will be described.

FIG. 1 shows an embodiment of the liquid crystal device according to the present invention. The liquid crystal device 1 includes a liquid crystal panel 2 and
For example, a frame 4 having a flat light guide 3, an LED substrate 6 as a light emitting element substrate, a control substrate 7 as a support substrate, and a shielding tape 8 as a shielding member are provided. The light guide 3 and the frame 4 can be integrally formed of resin, or they can be formed separately and then assembled together.

FIG. 2 shows a cross-sectional structure in which the above-described components are combined. As shown in FIG. 2, the liquid crystal panel 2 is disposed so as to face the light emitting surface (the upper side surface in FIG. 2) of the light guide 3, and the LED substrate 6 faces the side surface of the light guide 3, that is, the light receiving surface. The control board 7 is provided so as to face the non-light-emitting surface (the lower side face in FIG. 2) of the light guide 3, and the shielding tape 8 covers the openings 39 formed on both sides of the control board 7. As described above, the connection portion between the LED board 6 and the control board 7 is provided on the surface opposite to the side on which the light guide 3 is provided.
Note that a reflection sheet 25 is provided on the non-light-emitting surface of the light guide 3. In FIG. 1, the liquid crystal panel 2 has a pair of substrates 9a and 9b facing each other. These substrates 9a and 9b are formed by attaching electrodes and other necessary elements to a substrate material formed of a hard light-transmitting material such as glass or a flexible light-transmitting material such as plastic. It is formed.

In FIG. 2, the substrate material 1 of the first substrate 9a
On the liquid crystal side surface of 2a, that is, on the surface facing the second substrate 9b, for example, a first electrode 13a acting as a common electrode is provided.
Are formed in a predetermined pattern, an overcoat layer 14a is formed thereon, and an alignment film 16a is further formed thereon. Further, a polarizing plate 17a as an optical element is adhered to the outer surface of the substrate material 12a.

On the liquid crystal side surface of the substrate material 12b of the second substrate 9b facing the first substrate 9a, that is, on the surface facing the first substrate 9a, for example, a second electrode 13b acting as a segment electrode is formed in a predetermined pattern. The overcoat layer 14b is formed thereon, and the alignment film 16b is further formed thereon. Further, a polarizing plate 17b as an optical element is adhered to the outer surface of the substrate material 12b.

The optical element provided on both or one of the first substrate 9a and the second substrate 9b may be, if necessary, an element other than the polarizing plates 17a and 17b, for example, a retardation plate or a light diffusion plate. Etc. may be provided. In addition, a semi-transmissive reflector may be provided between the liquid crystal panel 2 and the light guide 3 as an optical element. Further, the substrate material 12a,
The 12b may be provided with other optical elements, for example, a color filter, if necessary.

The first electrode 13a and the second electrode 13b are formed of a transparent electrode such as ITO (Indium Tin Oxide) to a thickness of about 1000 Å, and the overcoat layers 14a and 14b Or a mixture thereof, etc.
The alignment films 16a and 16b are formed to a thickness of about 800 angstroms using, for example, a polyimide resin.

As shown in FIG. 1, the first electrode 13a is formed in a so-called stripe shape by arranging a plurality of linear patterns in parallel with each other. On the other hand, the second electrode 13b is formed by arranging a plurality of linear patterns parallel to each other so as to intersect with the first electrode 13a.
Again, it is formed in a stripe shape. These electrodes 13a
A plurality of points where the pixel and the electrode 13b intersect in a dot matrix form pixels for displaying an image. An area defined by the plurality of pixels is a display area for displaying an image such as a character.

The first substrate 9a formed as described above
As shown in FIG. 2, a plurality of spacers 18 are dispersed on one of the liquid crystal side surfaces of the second substrate 9b and the sealing material 11 on the liquid crystal side surface of one of the substrates.
For example, the sealing material 11 is provided in a frame shape by printing or the like as shown in FIG.
Is formed.

As shown in FIG. 2, between the substrates 9a and 9b, uniform dimensions held by spacers 18,
For example, a gap of about 5 μm, that is, a so-called cell gap is formed, and the liquid crystal 19 is injected into the cell gap through the liquid crystal injection port 11a (see FIG. 1).
The liquid crystal injection port 11a is sealed with a resin or the like.

In FIG. 1, the first substrate 9a is the second substrate 9
The first electrode 13a on the first substrate 9a extends directly to the substrate overhang 9c to form a wiring 21a. Also, the second substrate 9
b has a substrate overhang 9d that extends outside the first substrate 9a, and the second electrode 13b on the second substrate 9b extends directly to the substrate overhang 9d to form a wiring 21b.

In practice, a large number of the electrodes 13a and 13b and the wirings 21a and 21b extending therefrom are formed at very narrow intervals over the entire surface of each of the substrates 9a and 9b. In each of the drawings, the electrodes and the like are schematically illustrated at intervals wider than the actual intervals in order to clearly show the structure, and some of the electrodes are not illustrated. Further, the electrodes 13a and 13b formed in the region where the liquid crystal is sealed are not limited to being formed in a linear shape, but may be formed as a pattern such as an appropriate character or graphic.

In FIG. 1, the substrate overhangs 9c and 9d
Has a TCP (Tape Carrier Package) 22
a and 22b are anisotropic conductive adhesive elements such as ACF (An
The connection is made by an isotropic conductive film (23).

As is well known, the ACF 23 is a conductive polymer film used for electrically connecting the pair of terminals anisotropically and collectively connecting them.
As shown in the figure, a thermoplastic or thermosetting resin film 2
4 is formed by including a large number of conductive particles 26 in a dispersed state.

In FIG. 1, TCPs 22a and 22b
Is an IC structure formed by using the TAB technology. For example, an FPC (Flexible P
liquid crystal driving ICs 29a and 29
b is formed by bonding, for example, gang bonding. Reference numerals 30a and 30b indicate terminals for making electrical connection with an external circuit.

The substrate overhang portion 9c and the T
The TCP 22a is bonded to the substrate overhang portion 9c by thermocompression bonding with the CP 22a, that is, pressing under heating, and a unidirectional conductivity is provided between the wiring 27 of the TCP 22a and the wiring 21a on the substrate overhang portion 9c. Realize the connection that has. Further, similar bonding and conductive connection are realized between the substrate overhang portion 9d and the TCP 22b.

The liquid crystal panel 2 formed as described above
With respect to, a scanning voltage is sequentially applied to one of the first electrode 13a and the second electrode 13b in a linear pattern by the liquid crystal driving ICs 29a and 29b, and simultaneously, the other of the electrodes is based on a display image. By applying data voltage to each linear pattern,
The light passing through each pixel portion selected by the application of both voltages is modulated, so that a character,
Displays images such as numbers.

The LED substrate 6 provided on the non-light-emitting surface (lower surface in FIG. 1) of the light guide 3 is, as shown in FIG.
A plurality of LEDs 31 serving as light emitting elements are formed by lower side hem portions 6a on both sides and a higher beam portion 6b bridged between the hem portions 6a, and a plurality of LEDs 31 as light emitting elements are arranged in the longitudinal direction of the beam portion 6b. Are mounted at appropriate intervals over the entire area. Beam 6b
Are notched at predetermined intervals at the bottom of the
Are provided, and the plurality of LEDs 31
7 are provided. A terminal 32 is formed on the foot 6a of the LED substrate 6, and the terminal 32, the LED 31, and other electronic components (not shown) provided as needed are connected to the inside or the surface of the LED substrate 6. Wiring (not shown) is formed.

As shown in FIG. 1, the LED substrate 6 is mounted on the frame 4 or the light guide 3 from the non-light emitting surface side of the light guide 3 (the lower surface side in FIG. 1). For this mounting, for example, the skirt 6a of the LED substrate 6 is inserted into an opening (not shown) formed between the light guide 3 and the frame 4 without using a special fixing means such as a screw or an adhesive. Can be achieved by doing

With the skirt 6a of the LED substrate 6 mounted on the frame 4 or the light guide 3, as shown in FIG.
The beam portion 6b of the D substrate 6 is disposed at the side surface of the light guide 3, that is, at a position facing the light receiving surface, whereby the LED 31 mounted on the beam portion 6b faces the light receiving surface of the light guide 3. Placed. This state can be clearly understood by looking at the cross-sectional structure of FIG.

In FIG. 3A, the control board 7 is formed of a non-flexible material such as a glass epoxy resin, and has a rear surface (a lower surface side in FIG. 3A)
A control circuit 33, internal area terminals 34a and 34b, and edge terminals 36 are provided. The control circuit 33 controls the operation of the liquid crystal driving ICs 29a and 29b of the liquid crystal panel 2 (see FIG. 1), controls the lighting operation of the LED 31, or an electronic device using the liquid crystal device 1, for example, a portable device. It controls the operation of telephones, personal digital assistants, etc.

As shown in FIG. 1, the internal area terminal 34a is connected to the terminal 3 of the TCP 22a extending from the liquid crystal panel 2.
0a is a terminal to be connected. Also, the internal area terminal 34
b is another TCP 22b extending from the liquid crystal panel 2.
Are connected to the terminal 30b. In addition, a plurality of protrusions 38 are formed at an edge of the control board 7 to which the LED board 6 is connected, and openings 39 are necessarily formed on both sides of these protrusions 38.

In FIG. 1, the control board 7 is mounted on the frame 4 on which the LED board 6 is mounted, from the non-light emitting surface side of the light guide 3 (the lower surface side in FIG. 1). In this mounting, for example, a fixing projection (not shown) is provided at an appropriate position of the frame 4 without using a special fixing means such as a screw or an adhesive, and the control board 7 is stopped using the projection. Can be achieved by: Further, the control board 7 may be simply mounted on the light guide 3 while guiding the control board 7 with the frame 4 without necessarily using such fixing means.

When the control board 7 is mounted on the frame 4 in this manner, as shown in FIG. 3 (b), the LE 38 is engaged with the projection 38 of the control board 7 in the recess 37 of the LED board 6.
The LED board 6 and the control board 7 are assembled together so that the D board 6 extends in the thickness direction ZZ of the control board 7 and in the illustrated embodiment, both extend in a direction substantially perpendicular to each other. At this time, each LED 31 is accommodated in an opening 39 which is necessarily formed on both sides of the convex portion 38 of the control board 7.

When the LED board 6 and the control board 7 are assembled together, the terminal 32 of the LED board 6 and the control board 7
Are in contact with each other in a positional relationship that is mutually coincident with each other. The contact portion between the terminal 32 and the terminal 36 is conductively connected, for example, by soldering, so that the LED board 6 is electrically and mechanically connected to the control board 7 to form the light source board 41 for illumination. You.

In the illumination light source substrate 41 thus formed, the LED substrate 6 and the control substrate 7 are assembled by fitting the concave portions 37 and the convex portions 38 provided respectively, so that the thickness direction ZZ Of the conventional structure (FIG. 5)
), That is, the overall shape can be made very thin. For this reason, the dimension of the liquid crystal device 1 configured using the illumination light source 41 in the thickness direction (ZZ direction in FIG. 1) can be reduced.

The LE 38 is formed by the projection 38 of the control board 7.
Since the D board 6 can be pressed in the direction from the control board 7 to the light guide 3 in FIG. 1, it is possible to prevent the LED 31 from being displaced for a long time. In addition, LE
By fitting the concave portion 37 of the D substrate 6 and the convex portion 38 of the control substrate 7, the two substrates can be directly positioned with respect to each other, so that the soldering process for connecting the two substrates can be performed accurately and quickly. it can.

Thereafter, in FIG. 1, the control board 7 is mounted on the frame 4 with the LED board 6 and the control board 7 mounted.
A shielding tape 8 is attached to the surface of the connection portion between the LED substrate 6 and the control substrate 7 on the side opposite to the side on which the light guide is provided so as to cover the opening 39 of the LED substrate 6. The function and effect of the shielding tape 8 will be described later.

In FIG. 1, the liquid crystal panel 2 is mounted on the frame 4 such that the image display surface side is on the outside. At this time, one of the TCPs 22b is bent so that the tip thereof passes through a space K formed between the frame 4 and the light guide 3 in the vertical direction in the drawing. After the liquid crystal panel 2 is thus supported and arranged on the light emitting surface of the light guide 3 by the frame 4, one TCP 22 a is bent to the back side of the control board 7 through the cutout 42 provided in the frame 4,
Then, as shown in FIG. 2, the tip terminal 30a is connected to the internal area terminal 34a formed on the back surface of the control board 7 by, for example, soldering.

On the other hand, in FIG.
2b is similarly bent to the back side of the control board 7 through the light guide 3 and the frame 4, and its tip terminal 30b
Are the internal area terminals 34b formed on the back surface of the control board 7.
Are connected by, for example, soldering.

As described above, the liquid crystal device 1 disassembled and shown in FIG. 1 is manufactured.
As shown in (b), when adopting a structure for accommodating the LED 31 by the opening 39 formed in the control board 7 in order to reduce the thickness dimension, through this opening 39,
There is a possibility that flux, dust and the like may enter the liquid crystal panel 2 side. Before connecting the TCPs 22a and 22b to the internal area terminals 34a and 34b of the control board 7,
If the shielding tape 8 is attached to the connection portion between the LED board 6 and the control board 7 so as to cover the
It is possible to prevent the flux and the like and the dust from entering the space.

(Other Embodiments) The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications may be made within the scope of the invention described in the claims. Can be modified.

For example, in the embodiment shown in FIG. 1, the illumination light source substrate according to the present invention is applied to a liquid crystal device. However, the illumination light source substrate can be applied to other electro-optical devices, for example, EL devices, plasma displays, and the like. .

Further, the number of LEDs as light emitting elements is not limited to a specific number.
Any light emitting element other than D can be applied.

[0051]

According to the illumination light source substrate and the liquid crystal device of the present invention, the light emitting element substrate and the support substrate are not simply connected to each other by overlapping, but the recess provided in the light emitting element substrate and the support substrate are connected to each other. Since the two are connected in a state where the provided protrusions are fitted, the dimension in the thickness direction is small,
That is, the overall shape can be reduced.

Further, since the light emitting element substrate can be pressed by the convex portion of the support substrate, it is possible to prevent the light emitting element from being displaced for a long time. Furthermore, since the two substrates can be directly positioned with respect to each other by fitting the concave portion of the light emitting element substrate and the convex portion of the support substrate, soldering processing for connecting the two substrates can be performed accurately and quickly. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an illumination light source substrate according to the present invention and an embodiment of a liquid crystal device according to the present invention in an exploded state.

FIG. 2 is a cross-sectional view illustrating a cross-sectional structure of the liquid crystal device taken along line II-II of FIG.

FIGS. 3A and 3B are diagrams showing in detail an illumination light source substrate used in FIG. 1, wherein FIG. 3A shows a state before an LED substrate and a control substrate are connected, and FIG. This shows the state after connection.

FIG. 4 is a diagram showing a main part of the structure shown in FIG. 1;
It is a figure showing the state where an ED board was attached to a light guide.

FIG. 5 is a diagram showing an example of a conventional illumination light source substrate.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 liquid crystal device 2 liquid crystal panel 3 light guide 4 frame 6 LED substrate (light emitting element substrate) 6 a foot 6 b beam 7 control substrate (support substrate) 8 shielding tape 9 a, 9 b substrate 9 c, 9 d substrate overhang 13 a, 13 b electrode Reference Signs List 19 liquid crystal 22a, 22b TCP (connection substrate) 31 LED (light emitting element) 37 concave portion 38 convex portion 39 opening 41 illumination light source substrate Z thickness direction

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/00 336 F21Y 101: 02 // F21Y 101: 02 G02F 1/1335 530

Claims (5)

[Claims] A light emitting element substrate on which the light emitting element is mounted;
A support substrate to which the light-emitting element substrate is connected, wherein the light-emitting element substrate is a lighting light source substrate that projects in the thickness direction of the support substrate; A light source substrate for lighting, wherein the light emitting device substrate and the support substrate are connected to each other in a state where a portion is provided and a convex portion of the support substrate is fitted into a concave portion of the light emitting device substrate. 2. The light source substrate for illumination according to claim 1, wherein a plurality of the light emitting elements are provided on the light emitting element substrate, and the recess is formed between adjacent light emitting elements. 3. The light source substrate for illumination according to claim 1, wherein the light emitting element is accommodated in an opening formed beside a convex portion of the support substrate. 4. A liquid crystal panel in which liquid crystal is sealed between a pair of substrates, a light emitting element substrate on which a light emitting element is mounted, a support substrate to which the light emitting element substrate is connected, and light from the light emitting element. In a liquid crystal device having a light guide for guiding to the liquid crystal panel, a concave portion is provided in the light emitting element substrate, a convex portion is provided in the support substrate, and a convex portion of the support substrate is fitted in the concave portion of the light emitting element substrate. A liquid crystal device, wherein the light emitting element substrate and the support substrate are connected to each other in a state in which the light emitting element substrate is in an inclined state. 5. A connection portion between the light emitting element substrate and the support substrate, on a side where the light guide is provided, so as to cover openings formed on both sides of the convex portion of the support substrate. The liquid crystal device according to claim 4, wherein a shielding member is provided on the opposite side.