JP3994600B2 - Light source substrate for illumination and liquid crystal device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination light source substrate including a light emitting element and a liquid crystal device configured using the same.
[0002]
[Prior art]
Examples of the electro-optical device that performs a predetermined operation using light include a liquid crystal device, an optical device using an electroluminescence (EL) element, a plasma display (PDP), an optical device using a field emission element (FED), and the like. As described above, various types are conventionally known.
[0003]
Considering a liquid crystal device as this electro-optical device, this liquid crystal device modulates the light passing through the liquid crystal by controlling the voltage applied to the liquid crystal and controlling the orientation of the liquid crystal, thereby having letters, numbers, An image such as a figure is displayed. As this liquid crystal device, one using a light source substrate 51 for illumination shown in FIG.
[0004]
The conventional illumination light source substrate 51 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. For example, the support substrate 54 is configured as a control substrate on which various control circuits are mounted. When the illumination light source substrate 51 is incorporated in the liquid crystal device, the light emitting surface of the LED 52 is disposed at a position facing the light capturing surface of the light guide 56 as shown in FIG.
[0005]
In the liquid crystal device using the illumination light source substrate 51, the light from the LED 52 is taken into the light guide 56, and the light R having a uniform intensity is emitted from the light emitting surface. (Not shown) and used to display a visible image such as a character.
[0006]
[Problems to be solved by the invention]
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 ingenuity. For this reason, the conventional illumination light source substrate 51 has a problem that the dimension in the thickness direction ZZ is large, and therefore the thickness dimension of the liquid crystal device using the same is also large.
[0007]
The present invention has been made in view of the above-described problems, and an object thereof is to provide an illumination light source substrate and a liquid crystal device having a small size in the thickness direction.
[0008]
[Means for Solving the Problems]
(1) In order to achieve the above object, an illumination light source substrate according to the present invention includes a light emitting element substrate on which a light emitting element is mounted, and a support substrate to which the light emitting element substrate is connected. The substrate is a light source substrate for illumination projecting in the thickness direction of the support substrate, wherein the light emitting element substrate is provided with a recess, the support substrate is provided with a protrusion, and the light emitting element substrate is provided with a protrusion on the support substrate. The light emitting element substrate and the support substrate are connected to each other in a fitted state.
[0009]
According to this light source substrate for illumination, the light emitting element substrate and the support 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 support substrate are fitted. Therefore, the dimension in the thickness direction can be reduced, that is, the overall shape can be reduced.
[0010]
In addition, 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 period of time. Furthermore, since the two substrates can be directly positioned by fitting the concave portion of the light emitting element substrate and the convex portion of the support substrate, the soldering process for connecting the two substrates can be performed accurately and quickly. .
[0011]
(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, and in this case, the concave portion is formed between adjacent light emitting elements. It is desirable that In this way, the thickness dimension can be further reduced.
[0012]
(3) In the illumination light source substrate described in the above item (1) or (2), it is desirable that the light emitting element is accommodated in an opening formed beside the convex portion of the support substrate. In this way, the thickness dimension can be further reduced.
[0013]
(4) Next, a liquid crystal device according to the present invention includes a liquid crystal panel in which liquid crystal is sealed between a pair of substrates, a light emitting element substrate on which the light emitting element is mounted, and a support substrate to which the light emitting element substrate is connected. And a light guide for guiding light from the light emitting element to the liquid crystal panel, the light emitting element substrate is provided with a recess, the support substrate is provided with a protrusion, and the light emitting element substrate is provided with a recess. The light emitting element substrate and the support substrate are connected to each other in a state where the convex portions of the support substrate are fitted.
[0014]
According to this liquid crystal device, the light emitting element substrate and the support substrate are not simply overlapped and connected, but both the concave portion provided on the light emitting element substrate and the convex portion provided on the support substrate are fitted together. Thus, the dimension in the thickness direction of the illumination light source substrate composed of the light emitting element substrate and the support substrate can be reduced, and as a result, the overall shape of the liquid crystal device can be reduced in thickness.
[0015]
(5) With regard to the liquid crystal device according to the above (4), the connection portion between the light emitting element substrate and the support substrate 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 the side opposite to the side where the light guide is disposed.
[0016]
When adopting a structure in which the LED is accommodated by an opening formed in the control board in order to reduce the thickness dimension, there is a possibility that flux, dust, etc. may enter the liquid crystal panel through the opening. Before connecting the TCP to the internal area terminal of the control board, if a shielding tape is affixed to the connection part of the LED board and the control board so as to block the opening, such as flux to the liquid crystal panel and dust etc. Can be prevented from entering.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the case where the illumination light source substrate according to the present invention is used as a light source of a liquid crystal device will be described as an example.
[0018]
FIG. 1 shows an embodiment of a liquid crystal device according to the present invention. The liquid crystal device 1 includes a liquid crystal panel 2, a frame 4 provided with a flat light guide 3, for example, an LED substrate 6 as a light emitting element substrate, a control substrate 7 as a support substrate, and a shielding member. And a shielding tape 8. The light guide 3 and the frame 4 can be integrally formed of resin, or both can be assembled after being formed separately.
[0019]
FIG. 2 shows a cross-sectional structure in which the above elements are combined. As shown in FIG. 2, the liquid crystal panel 2 is disposed to face the light emitting surface (upper side surface of 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 capturing surface. The control board 7 is arranged to face the non-light emitting surface (the lower side of FIG. 2) of the light guide 3, and the shielding tape 8 blocks the openings 39 formed on both sides of the control board 7. Thus, it arrange | positions on the surface on the opposite side to the side by which the light guide 3 was arrange | positioned of the connection part of the LED board 6 and the control board 7. FIG. A reflective sheet 25 is provided on the non-light emitting surface of the light guide 3. The liquid crystal panel 2 has a pair of substrates 9 a and 9 b facing each other in FIG. 1, and these substrates are bonded to each other by a sealing material 11. 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.
[0020]
In FIG. 2, a first electrode 13a acting as a common electrode, for example, is formed in a predetermined pattern on the liquid crystal side surface of the substrate material 12a of the first substrate 9a, that is, the surface facing the second substrate 9b. An overcoat layer 14a is formed, and an alignment film 16a is further formed thereon. A polarizing plate 17a as an optical element is attached to the outer surface of the substrate material 12a.
[0021]
On the liquid crystal side surface of the substrate material 12b of the second substrate 9b facing the first substrate 9a, that is, the surface facing the first substrate 9a, for example, a second electrode 13b acting as a segment electrode is formed in a predetermined pattern, An overcoat layer 14b is formed thereon, and an alignment film 16b is further formed thereon. A polarizing plate 17b as an optical element is attached to the outer surface of the substrate material 12b.
[0022]
In addition, as an optical element provided in both or one side of the 1st board | substrate 9a and the 2nd board | substrate 9b, elements other than polarizing plate 17a, 17b, for example, a phase difference plate, a light diffusing plate, etc. are provided as needed. Sometimes. A transflective plate may be provided as an optical element between the liquid crystal panel 2 and the light guide 3. Further, the substrate materials 12a and 12b can be provided with other optical elements such as a color filter, if necessary.
[0023]
The first electrode 13a and the second electrode 13b are formed to a thickness of about 1000 angstroms by a transparent electrode such as ITO (Indium Tin Oxide), and the overcoat layers 14a and 14b are made of, for example, silicon oxide, titanium oxide, or their The alignment films 16a and 16b are formed with a thickness of about 800 angstroms by, for example, a polyimide resin.
[0024]
As shown in FIG. 1, the first electrode 13 a 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 also formed in a stripe shape by arranging a plurality of linear patterns parallel to each other so as to intersect the first electrode 13a. A plurality of points where these electrodes 13a and 13b intersect in a dot matrix form a pixel for displaying an image. An area partitioned by the plurality of pixels is a display area for displaying an image such as a character.
[0025]
As shown in FIG. 2, a plurality of spacers 18 are dispersed on the liquid crystal side surface of one of the first substrate 9a and the second substrate 9b formed as described above. A sealing material 11 is provided on the liquid crystal side surface in a frame shape as shown in FIG. 1 by, for example, printing, and a liquid crystal injection port 11 a is formed in a part of the sealing material 11.
[0026]
As shown in FIG. 2, a uniform dimension held by the spacer 18, for example, a gap of about 5 μm, a so-called cell gap, is formed between the substrates 9a and 9b, and is passed through the liquid crystal inlet 11a (see FIG. 1). Liquid crystal 19 is injected into the cell gap, and after the injection is completed, the liquid crystal injection port 11a is sealed with resin or the like.
[0027]
In FIG. 1, the first substrate 9a has a substrate overhanging portion 9c that protrudes to the outside of the second substrate 9b, and the first electrode 13a on the first substrate 9a directly extends to the substrate overhanging portion 9c to form the wiring 21a. It has become. Further, the second substrate 9b has a substrate overhanging portion 9d that protrudes to the outside of the first substrate 9a, and the second electrode 13b on the second substrate 9b extends directly to the substrate overhanging portion 9d to become a wiring 21b. ing.
[0028]
The electrodes 13a and 13b and the wirings 21a and 21b extending from the electrodes 13a and 21b are actually formed on the entire surface of the respective substrates 9a and 9b at a very narrow interval. In FIG. In order to show the structure in an easy-to-understand manner, the electrodes and the like are schematically shown at intervals wider than the actual intervals, and some of the electrodes are not shown. In addition, the electrodes 13a and 13b formed in the region where the liquid crystal is sealed are not limited to being formed in a straight line, and may be formed as a pattern such as an appropriate character or figure.
[0029]
In FIG. 1, TCP (Tape Carrier Package) 22a and 22b are connected to the substrate overhanging portions 9c and 9d by anisotropic conductive adhesive elements, for example, ACF (Anisotropic Conductive Film) 23, respectively. .
[0030]
As is well known, the ACF 23 is a conductive polymer film that is used to electrically connect a pair of terminals with anisotropy and is electrically connected. For example, as shown in FIG. Alternatively, it is formed in the thermosetting resin film 24 by including a large number of conductive particles 26 in a dispersed state.
[0031]
In FIG. 1, TCPs 22a and 22b are IC structures configured by using TAB technology. For example, liquid crystal driving ICs 29a and 29b are bonded to an FPC (Flexible Printed Circuit) 28 in which wirings 27 are formed, respectively. For example, it is formed by gang bonding. Reference numerals 30a and 30b indicate terminals for electrical connection with an external circuit.
[0032]
The substrate overhanging portion 9c and the TCP 22a are sandwiched between the ACF 23 by thermocompression bonding, that is, the pressure is applied under heating, so that the TCP 22a is bonded to the substrate overhanging portion 9c, and the TCP 27a wiring 27 and the wiring over the substrate overhanging portion 9c To achieve a unidirectional conductive connection between them. Further, the same adhesion and conductive connection are realized between the substrate overhanging portion 9d and the TCP 22b.
[0033]
With respect to the liquid crystal panel 2 formed as described above, a scanning voltage is sequentially applied in a linear pattern to either the first electrode 13a or the second electrode 13b by the liquid crystal driving ICs 29a and 29b, and at the same time, By applying a data voltage based on the display image to each of the linear patterns to the other of the electrodes, the light passing through each pixel portion selected by the application of both voltages is modulated, so that the substrate 9a or 9b Images such as letters and numbers are displayed on the outside.
[0034]
As shown in FIG. 3 (a), the LED substrate 6 provided on the non-light emitting surface (lower side surface of FIG. 1) side of the light guide 3 includes a skirt 6a on both sides having a low height, and skirts thereof. A plurality of LEDs 31 serving as light emitting elements are mounted at appropriate intervals in the longitudinal direction of the beam portion 6b. The bottom of the beam portion 6 b is notched with a predetermined interval, that is, a recess 37 is provided, and the plurality of LEDs 31 are provided so as to sandwich the recess 37. Terminals 32 are formed on the skirt 6a of the LED board 6, and the terminals 32, LEDs 31 and other electronic components (not shown) provided as needed are connected to the inside or the surface of the LED board 6. Wiring (not shown) is formed.
[0035]
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 (the lower surface side in FIG. 1) of the light guide 3. For this mounting, for example, the skirt 6a of the LED board 6 is inserted into an opening (not shown) formed between the light guide 3 and the frame 4 without using any special fixing means such as screws or adhesives. Can be achieved.
[0036]
With the skirt 6a of the LED substrate 6 mounted on the frame 4 or the light guide 3, the beam 6b of the LED substrate 6 faces the side surface of the light guide 3, that is, the light capturing surface, as shown in FIG. Accordingly, the LED 31 mounted on the beam portion 6b is arranged to face the light capturing surface of the light guide 3. This state can be clearly understood by looking at the cross-sectional structure of FIG.
[0037]
In FIG. 3A, the control board 7 is formed of an inflexible material such as glass epoxy resin, for example, and on the back side (the lower side of FIG. 3A), the control circuit 33 and the internal region are formed. Terminals 34a and 34b and side 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 in which the present liquid crystal device 1 is used, for example, a mobile phone. Control the operation of telephones, personal digital assistants, etc.
[0038]
Further, as shown in FIG. 1, the internal region terminal 34 a is a terminal to which a terminal 30 a of the TCP 22 a extending from the liquid crystal panel 2 is connected. The internal region terminal 34b is a terminal to which a terminal 30b of another TCP 22b extending from the liquid crystal panel 2 is connected. In addition, a plurality of convex portions 38 are formed on the side end portion of the control substrate 7 to which the LED substrate 6 is connected, and openings 39 are inevitably formed on both sides of the convex portions 38.
[0039]
In FIG. 1, the control board 7 is attached from the non-light emitting surface side (lower surface side in FIG. 1) of the light guide 3 to the frame 4 in a state where the LED board 6 is attached. For this mounting, for example, a fixing protrusion (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 protrusion. Can be achieved. Further, it is not always necessary to use such fixing means, and the control board 7 may be simply mounted on the light guide 3 while being guided by the frame 4.
[0040]
When the control board 7 is mounted on the frame 4 in this way, the LED board 6 is in a state where the convex part 38 of the control board 7 is fitted in the concave part 37 of the LED board 6 as shown in FIG. In the illustrated embodiment, the LED board 6 and the control board 7 are assembled to each other so that both extend in a direction substantially perpendicular to each other so as to project in the thickness direction ZZ of the control board 7. At this time, each LED 31 is accommodated in an opening 39 inevitably formed on both sides of the convex portion 38 of the control board 7.
[0041]
When the LED board 6 and the control board 7 are assembled to each other, the terminals 32 of the LED board 6 and the side edge terminals 36 of the control board 7 are in contact with each other in a positional relationship that coincides with each other. Then, the contact portion between the terminal 32 and the terminal 36 is subjected to conductive connection processing such as soldering, whereby the LED substrate 6 is electrically and mechanically connected to the control substrate 7 to form the illumination light source substrate 41. The
[0042]
With respect to the illumination light source substrate 41 formed in this way, the LED substrate 6 and the control substrate 7 are assembled by fitting the concave portion 37 and the convex portion 38 provided in each, so that the dimension H in the thickness direction Z-Z. Is much smaller than that of the conventional structure (see FIG. 5), that is, the overall shape can be made very thin. For this reason, the dimension in the thickness direction (the ZZ direction in FIG. 1) of the liquid crystal device 1 configured using the illumination light source 41 can be reduced.
[0043]
Further, since the LED substrate 6 can be pressed from the control substrate 7 toward the light guide 3 in FIG. 1 by the convex portion 38 of the control substrate 7, it is possible to prevent the positional deviation of the LED 31 from occurring for a long period of time. Further, since the two substrates can be directly positioned by fitting the concave portion 37 of the LED substrate 6 and the convex portion 38 of the control substrate 7, a soldering process for connecting the two substrates is performed accurately and quickly. be able to.
[0044]
Thereafter, in FIG. 1, in a state where the LED board 6 and the control board 7 are mounted on the frame 4, light is guided on the surface of the connection portion between the LED board 6 and the control board 7 so as to close the opening 39 of the control board 7. The shielding tape 8 is stuck on the side opposite to the side where the body is disposed. The effect of the shielding tape 8 will be described later.
[0045]
In FIG. 1, the liquid crystal panel 2 is mounted on the frame 4 with the image display surface side facing outward. At this time, one of the TCPs 22b is bent so that its tip passes through the space K formed between the frame 4 and the light guide 3 in the vertical direction in the figure. Thus, after the liquid crystal panel 2 is arranged on the light emitting surface of the light guide 3 so as to be supported by the frame 4, one TCP 22 a is bent to the back side of the control board 7 through the notch portion 42 provided in the frame 4. As shown in FIG. 2, the tip terminal 30a is connected to an internal region terminal 34a formed on the back surface of the control board 7, for example, by soldering.
[0046]
On the other hand, in FIG. 1, the other TCP 22 b is similarly bent through the light guide 3 and the frame 4 to the back side of the control board 7, and the tip terminal 30 b is formed on the back side of the control board 7. The region terminal 34b is connected by, for example, soldering.
[0047]
As described above, the liquid crystal device 1 shown in the exploded view in FIG. 1 is manufactured. As shown in FIGS. 3A and 3B, the control board 7 is used to reduce the thickness dimension. When the structure in which the LED 31 is accommodated by the opening 39 formed in the above is adopted, there is a possibility that flux, dust or the like may enter the liquid crystal panel 2 through the opening 39. 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 part of the LED board 6 and the control board 7 so as to close the opening 39, such as Intrusion of flux and dust into the liquid crystal panel 2 can be prevented.
[0048]
(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 can be made within the scope of the invention described in the claims.
[0049]
For example, in the embodiment of FIG. 1, the illumination light source substrate according to the present invention is applied to the liquid crystal device, but the illumination light source substrate can also be applied to other electro-optical devices such as EL devices and plasma displays.
[0050]
Further, the number of LEDs as light emitting elements is not limited to a specific number, and any light emitting element other than LEDs can be applied as the light emitting elements.
[0051]
【The invention's effect】
According to the illumination light source substrate and the liquid crystal device according to the present invention, the light emitting element substrate and the support 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 support substrate are provided. Since both of them are connected in a state of being fitted, the dimension in the thickness direction can be reduced, that is, the overall shape can be reduced.
[0052]
In addition, 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 period of time. Furthermore, since the two substrates can be directly positioned by fitting the concave portion of the light emitting element substrate and the convex portion of the support substrate, the soldering process 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 a light source substrate for illumination 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 showing a cross-sectional structure of the liquid crystal device according to the line II-II in FIG.
FIG. 3 is a diagram showing in detail the light source substrate for illumination used in FIG. 1, wherein (a) shows a state before the LED substrate and the control substrate are connected, and (b) shows the LED substrate and the control substrate. The state after connection is shown.
4 is a diagram showing a main part of the structure shown in FIG. 1, and is a diagram showing a state where an LED substrate is mounted on a light guide. FIG.
FIG. 5 is a diagram showing an example of a conventional illumination light source substrate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Liquid crystal device 2 Liquid crystal panel 3 Light guide 4 Frame 6 LED substrate (light emitting element substrate)
6a Hem 6b Beam 7 Control board (support board)
8 Shielding tape 9a, 9b Substrate 9c, 9d Substrate overhanging portion 13a, 13b Electrode 19 Liquid crystal 22a, 22b TCP (connection substrate)
31 LED (light emitting element)
37 Concave part 38 Convex part 39 Opening 41 Light source substrate Z for illumination Thickness direction

Claims (4)

A light-emitting element substrate on which a light-emitting element is mounted; and a support substrate to which the light-emitting element substrate is connected. The light-emitting element substrate extends in the thickness direction of the support substrate.
The light emitting element substrate is provided with a concave portion, the support substrate is provided with a convex portion, and the convex portion of the support substrate is fitted into the concave portion of the light emitting element substrate. Connected to each other,
The light source substrate for illumination, wherein the light emitting element is accommodated in an opening formed beside a convex portion of the support substrate.   The illumination light source substrate according to claim 1, wherein a plurality of the light emitting elements are provided on the light emitting element substrate, and the concave portion is formed between adjacent light emitting elements. 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 is guided 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 convex portion of the support substrate is fitted into the concave portion of the light emitting element substrate. Connected to each other,
The liquid crystal device, wherein the light emitting element is accommodated in an opening formed beside a convex portion of the support substrate.   The connection portion between the light emitting element substrate and the support substrate is shielded on the side opposite to the side where the light guide is disposed so as to block the openings formed on both sides of the convex portion of the support substrate. The liquid crystal device according to claim 3, further comprising a member.

Images