JP5868161B2 - Display device - Google Patents

Description

  The present invention relates to a backlight structure of a display device.

As a liquid crystal display device, a direct type configuration in which a backlight device is arranged on the back side of a liquid crystal panel is known.
FIG. 6 illustrates a configuration example of a conventional liquid crystal display device 620. The backlight device includes a heat radiating plate 600 inside a BL (backlight) case 601 formed by bending a sheet metal. A heat transfer sheet 602, a light source substrate 603, and a reflection diffusion sheet 604 are laminated in this order on the heat sink 600, and the case frame lid 610 is fastened to the BL case 601. Further, an optical sheet group 605 is arranged to form a diffusion space for making the light of the light emitting element of the light source substrate 603 into a uniform surface light source. In the case where the heat generation density of the light source substrate 603 is higher than the light emitting area of the backlight device, the BL case 601 and the heat radiating plate 600 may be made of different materials and manufactured as separate structures. In the combination of the BL case 601 and the heat radiating plate 600, there is an operation process of placing the heat radiating plate 600 on the assembly jig with one surface of the heat radiating plate 600, that is, the heat transfer sheet 602 side down. The heat radiating plate 600 is covered with a BL case 601 from above, and fastened with screws 609 from the back side of the BL case 601. Thereafter, the heat transfer sheet 602, the light source substrate 603, and the reflection diffusion sheet 604 are laminated on the heat radiating plate 600, and the heat radiating plate 600 or the BL case 601 is shared with fastening rivets or screws (not shown) from the reflection diffusion sheet 604 side. Assembled by tightening.

  As described above, in the structure in which the heat radiating plate 600 is arranged inside the BL case 601, the end of the BL case 601 on the display panel 607 side has no folded flange portion. In other words, when the folded flange portion exists, the area of the heat sink 600 disposed inside the BL case 601 is restricted. According to the configuration of FIG. 6, the area of the heat radiating plate 600 can be increased, and the area of the light source substrate 603 can be increased, so that the projected area is wider than the effective display area of the display panel 607. The light source element can be disposed on the substrate.

  In addition, a device disclosed in Patent Document 1 is disclosed as a technique related to narrowing the frame of a backlight device.

JP 2008-204794 A

  In the configuration shown in FIG. 6, an assembly jig for the heat radiating plate 600 and the BL case 601 and a case frame lid 610 which is a separate component from the BL case 601 are necessary. Further, the plate thickness of the BL case 601 is added to the thickness of the backlight device, which is disadvantageous for thinning. Therefore, a configuration in which the heat sink is coupled from the back side of the BL case is conceivable. In this case, while it is necessary to arrange the light source elements up to a projection area larger than the effective display area of the display panel, the external dimensions of the backlight device need to be reduced in order to narrow the frame of the display device. However, in the conventional configuration, it is difficult to meet this conflicting request.

  Accordingly, an object of the present invention is to improve the assemblability of the display device and to realize a narrow frame of the display device.

A display device according to the present invention is a display device that includes a display panel and a light source unit that emits light from the back side to the display panel, the light source substrate having a plurality of light source elements, and the light source substrate. A heat dissipating member disposed on the opposite side of the display panel, and a frame body that abuts on the outer peripheral edge of the heat dissipating member from the display panel side to form a side wall. among the body, the heat dissipation member abutting portion, said protrusion protruding to the light source substrate side is formed, the protruding portion is inserted into the cutout portion formed in the light source substrate, wherein A screw for fastening the heat dissipating member to the frame body is screwed into a screw hole formed in the projecting portion via a through hole portion of the heat dissipating member.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the assembly property of a display apparatus, the narrow frame of a display apparatus is realizable.

It is a figure which shows the example of a planar arrangement | positioning of a light source board | substrate, in order to demonstrate 1st Embodiment of this invention with FIG. 2 and 3. FIG. It is detailed drawing (A) and sectional drawing (C) which show the principal part of FIG. 1, and detailed drawing (B) and sectional drawing (D) of a comparative example. It is a figure which shows a modification about the shape of the protrusion part formed in the backlight case. It is a figure which shows the example of planar arrangement | positioning about the light source substrate which concerns on 2nd Embodiment of this invention. FIG. 5 is a detailed view (A) showing a main part of FIG. 4 and a view (B) showing a modification. It is sectional drawing of the principal part which shows the structural example of the conventional backlight apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
A display device according to a first embodiment of the present invention will be described with reference to FIGS.
1A and 1B are diagrams illustrating a part of a direct type backlight device that is a light source unit that irradiates light from the back side to a display panel. FIG. 1 particularly shows an arrangement example of the light source substrate. 2A is a detailed view of one light source substrate and its peripheral portion, and FIG. 2C is a cross-sectional view taken along the line CC in FIG. 2A.

  A plurality of light source elements 103e are mounted on the light source substrate 103b, and light emitting elements such as light emitting diodes are used. As shown in FIG. 2C, the heat transfer sheet 102 is disposed on one surface of the light source substrate 103b. This is, for example, a sheet member having a thickness of about 0.2 to 1.0 (mm) and a thermal conductivity of about 1 to 5 (W / m · K) and substantially the same shape as the light source substrate 103b. The heat transfer sheet 102 is coupled to the heat sink 100. The heat radiating plate is a heat radiating member made of plate-like aluminum having a thickness of about 1 to 3 (mm). The backlight (hereinafter abbreviated as “BL”) case 101 is a metal frame that abuts against a portion near the outer peripheral edge of the heat sink 100 from the display panel side to form a side wall. The reflection diffusion sheet 104 arranged on the irradiation surface side of the light source substrate 103b is formed with through holes corresponding to the respective light source elements 103e mounted on the light source substrate 103b. A surface light source is formed by forming a substantially sealed light source diffusion space using the optical sheet group 105.

Next, the planar arrangement of the light source substrate 103 will be described with reference to FIG.
The light source substrate 103 is composed of a total of 24 substrates of 3 vertical × 8 horizontal. In the example of FIG. 1A, the light source substrate 103 is classified into the following three types according to the number of sides adjacent to the BL case 101. .
14 light source substrates 103a in which one of the long side and the short side of the substrate is close to the BL case 101
-Four light source boards 103b at the corners where the two sides of the board are close to the BL case 101
-Six light source boards 103c in the center where all sides of the board are not close to the BL case 101.

  The light source substrates 103a, 103b, and 103c may basically have different shapes, but are preferably the same shape from the viewpoint of common use of the substrates. Therefore, the light source substrates 103a, 103b, and 103c have the same size rectangle so that the light source substrates 103a, 103b, and 103c can be placed anywhere, and a notch 103d is formed at the center of each side. The BL case 101 is formed with a plurality of protruding portions 101b protruding toward the light source substrate, and each protruding portion 101b is inserted into the notch 103d. The protruding portion 101 b has a role of connecting the BL case 101 and the heat sink 100 or a role of positioning the light source substrate 103. In the example of FIG. 1A, a fastening portion 101a is provided on the protruding portion 101b.

FIG. 1B shows another example of the arrangement of the light source substrates.
The light source substrate 113 includes two light source substrates 113 a whose three sides are close to the BL case 111 and two light source substrates 113 b whose two short sides are close to the BL case 111. The light source substrates 113a and 113b also preferably have the same shape from the viewpoint of common use of the substrates. Therefore, the notch portions 113d and 113e are formed on each side so that the light source substrates 113a and 113b can be arranged at any place. That is, a notch 113d is formed at the center of the two short sides facing each light source substrate, and a notch 113e is formed at the center of the two long sides facing each light source substrate. Yes. The protrusion 111b of the BL case 111 is inserted into the notches 113d and 113e. According to the arrangement shown in FIG. 1B, a positional relationship in which the long side of the light source substrate 113 is parallel to the short side of the BL case 111 by inserting the protruding portion 111b into the short-side cutout portion 113d. Can be maintained.

Next, the positional relationship between the notch formed in the light source substrate and the protruding portion of the BL case will be described with reference to FIG.
FIG. 2 is a detailed view of part A shown in FIG. FIG. 2A is a view when the heat sink 100 is attached to the back surface of the BL case 101 and viewed from a direction perpendicular to the light source substrate 103b. In FIG. 2A, only the heat radiating plate 100, the BL case 101, and the light source substrate 103b are shown so that the arrangement of the light source substrate can be seen. 2C further shows a heat transfer sheet 102, a reflection diffusion sheet 104, an optical sheet group 105, a panel support member 107, a display panel 106, and a panel holding frame 108 (front portion 108a). In the following description, the side approaching the display panel 106 is defined as the front.

  The backlight device includes a BL case 101 formed by bending a thin sheet metal, and has a configuration in which a heat radiating plate 100 is fastened with screws 109 on the back surface thereof. A light source substrate 103 is attached to the heat radiating plate 100 via a heat transfer sheet 102, and a reflection diffusion sheet 104 is disposed on the front surface of the light source substrate 103. The BL case 101 is provided with an optical sheet group 105 at the front end thereof, thereby forming a diffusion space for realizing a uniform surface light source using light from the light source element 103e of the light source substrate 103. When the heat generation density of the light source substrate 103 is higher than the light emitting area of the backlight device, the BL case 101 uses a cold-rolled steel plate to make the backlight device thinner, narrow the frame, and ensure rigidity. The heat radiating plate 100 is made of a metal material such as an aluminum plate having high thermal conductivity for radiating and diffusing the light source elements of the light source substrate 103.

  The BL case 101 and the heat radiating plate 100 are joined by fastening them to the back surface of the BL case 101 with screws 109 with the heat transfer sheet 102 side of the heat radiating plate 100 facing down. That is, the heat radiating plate 100 is fixed to the back surface of the BL case 101 by attaching the screw 109 to the screw hole of the fastening portion 101 a formed in the protruding portion 101 b of the BL case 101. Further, the heat transfer sheet 102, the light source substrate 103, and the reflection diffusion sheet 104 are fixed to the heat radiating plate 100 and the BL case 101 together by one-touch type fastening rivets and screws (not shown). A panel support member 107 is disposed outside the BL case 101, and a panel holding frame 108 is further provided outside the BL case 101. The display panel 106 using a liquid crystal panel or the like is sandwiched between the front end portion of the panel support member 107 and the front end portion of the panel holding frame 108. In a space formed by the panel support member 107 and the panel holding frame 108, a drive circuit portion of the display panel 106 and the like are arranged.

  2 (B) and 2 (D) show a configuration in which no protrusion is formed on the BL case 201 as a comparative example. FIG. 2B shows only the heat sink 200, the BL case 201, and the light source substrate 203 so that the arrangement of the light source substrate can be seen. 2D is a cross-sectional view taken along the line DD in FIG. 2B, and further includes a heat transfer sheet 202, a reflection diffusion sheet 204, an optical sheet group 205, a panel support member 207, a display panel 206, A panel holding frame 208 (front portion 208a) is shown.

  Hereinafter, the frame width A of the BL case 101 of the present embodiment and the frame width B of the BL case 201 of the comparative example will be described with reference to FIGS. 2 (A) and 2 (B). First, in FIG. 2A, the minimum distance between the outer peripheral edge of the BL case 101 and the center point of the fastening portion 101a is d1, and the minimum distance between the center point of the fastening portion 101a and the tip portion of the protruding portion 101b is d2. And On the other hand, in FIG. 2B, the distance between the center point of the fastening portion 201a and the inner peripheral edge portion of the BL case 201 is d2.

The protruding portion 101b of the BL case 101 is inserted into the cutout portion 103d of the light source substrate 103b, and the dimension of the protruding portion 101b protruding from the other portion toward the light source substrate 103b is d3. If the difference between the frame width A of the present embodiment and the frame width B of the comparative example is d4, the following relational expression holds.
A + d3 = d1 + d2 (1) equation B = d1 + d2 (2) equation d4 = BA−d3 (3) equation The thickness of the sheet metal plate of the BL case 101 is 0.8 (mm), As numerical examples when M3 burring tapping is performed on the fastening portion 101a, d1 = 5.5 (mm), d2 = 3.5 (mm), and d3 = 2.5 (mm). Substituting these into the equations (1) to (3) gives the following equation. The unit mm shown in parentheses is millimeters.
A = 5.5 + 3.5−2.5 = 6.5 (mm) (4) Formula B = 5.5 + 3.5 = 9.0 (mm) (5) Formula d4 = B− A = 2.5 (mm) (6) Formula According to the formula (6), in the case of the configuration in which the heat sink is attached to the back surface of the BL case, FIG. 2 (A) compared to FIG. 2 (B). In the present embodiment shown in FIG. 2, the frame width can be reduced by 2.5 (mm).

  The width W shown in FIG. 2A indicates the width of the notch 103d, that is, the width in the direction parallel to the short side of the light source substrate 103b. Moreover, the space | interval P shows the pitch of light source elements including the external size of the light source element 103e. Since the notch 103d is formed so as to satisfy the relationship of “W <P”, the position of the light source element 103e is not affected by interference between components.

Next, with reference to FIG. 2C and FIG. 2D, the thickness of the backlight device due to the difference in the detailed structure of the fastening portion between the BL case and the heat sink will be compared with a specific example.
First, in the configuration of FIG. 2D, a cylindrical convex portion 201b by burring tap processing protrudes forward from a fastening portion 201a between the BL case 201 and the heat sink 200. That is, the cylindrical convex portion 201b is provided on the side opposite to the heat radiating plate 200, and its height is about 0.8 (mm). The total value of this height and the plate thickness 0.8 (mm) of the BL case 201 is 1.6 (mm). The screw 209 is screwed into the hole of the fastening part 201a through the hole of the heat sink 200. The screw pitch of M3 is 0.5 (mm). In order to secure three or more ridges in the screw holes, the neck length of the screw 209 is 5 (mm) in consideration of the plate thickness 3.0 (mm) of the heat sink 200. In order to prevent the tip of the screw 209 from interfering with the reflection diffusion sheet 204, the total thickness of the heat transfer sheet 202 and the light source substrate 203 needs to be at least 2.0 (mm). Therefore, the total thickness including the heat sink 200, the heat transfer sheet 202, the light source substrate 203, and the reflection diffusion sheet 204 having a thickness of 1 (mm) is 6.0 (mm).

  On the other hand, in the configuration of FIG. 2C according to the present embodiment, the cylindrical convex portion 101c by burring tap processing protrudes rearward, that is, toward the heat dissipation plate 100. The height of the cylindrical protrusion 101c is 0.8 (mm), and is 1.6 (mm) when the plate thickness of the BL case 101 is included. The outer diameter of the cylindrical convex portion 101c is about Φ3.9 (mm), and the diameter of the cylindrical projection 101c enters the radiator plate 100 so that the cylindrical convex portion 101c enters the radiator plate 100 having a thickness of 3.0 (mm). A through hole 100a of about 5 to 5.0 (mm) is formed. The screw 109 is inserted into the through-hole portion 100 a and fastened to a screw hole formed in the fastening portion 101 a of the BL case 101. The screw 109 is an M3 screw having a screw head diameter of about Φ6-8 (mm). Regarding the fitting length of the screw 109, since the length including the sheet metal plate thickness of the cylindrical convex portion 101c is 1.6 (mm), it is possible to secure three or more threads in the screw hole in the fastening portion 101a. A stable fastening force can be obtained. When the neck length of the screw 109 is 4 (mm), in order to prevent the tip of the screw 109 from interfering with the reflection diffusion sheet 104, for example, the thickness of the heat transfer sheet 102 is 0.2 (mm), and the light source The thickness of the substrate 103 may be 1.0 (mm). Therefore, the total thickness including the heat sink 100, the heat transfer sheet 102, the light source substrate 103, and the reflection diffusion sheet 104 is 5.2 (mm). That is, the thickness can be reduced by 0.8 (mm) as compared with the total thickness 6.0 (mm) in the case of FIG. In the configuration of FIG. 2C, an increase due to the influence of the plate thickness of the BL case 101 is not added to the thickness of the backlight device, which is advantageous for thinning.

  When viewed from a direction orthogonal to the light source substrate 103b, the protruding portion 101b and the cutout portion 103d are in a positional relationship that does not overlap each other. For example, in FIG. 2C, when the thickness of the heat transfer sheet 102 is larger than the plate thickness of the BL case 101, a configuration in which the outer peripheral edge portion of the light source substrate 103b overlaps the protruding portion 101b is also conceivable. In the present embodiment, since the notch 103d is formed in the light source substrate 103b, the position of the light source substrate 103b can be determined with respect to the protruding portion 101b. In addition, when the protrusion part 101b has the positioning part of the light source substrate 103b, the said part engages with a notch part.

  Next, the shape of the protrusion formed on the BL case will be described with reference to FIG. In this example, the light source substrate 113b is positioned using the extending portion 301b extending in a direction perpendicular to the protruding portion shown in FIGS. 1A and 1B, that is, in a direction toward the display panel 106. . FIG. 3A is a perspective view of main parts showing the BL case 301 and the light source substrate 103b. FIG. 3B is a view when seen from a direction orthogonal to the light source substrate 103b. FIG. 3C is a cross-sectional view taken along line E-E in FIG. 3C further shows a heat transfer sheet 102, a reflection diffusion sheet 304, an optical sheet group 105, a panel support member 107, a display panel 106, and a panel holding frame 108. FIG. 3D is a perspective view showing a modification of the shape of the extending portion 301b.

In the example shown in FIG. 2A, the protruding portion 101b of the BL case 101 does not have an extending portion, and the protruding portion 101b and the light source substrate 103b are arranged on substantially the same plane. For this reason, the mounting position is not determined until the light source substrate 103b contacts the heat sink 100. Therefore, as shown in FIG. 3A, the extending portion 301b is provided in the protruding portion 101b, thereby realizing a structure in which the light source substrate 103b can be easily positioned on the heat radiating plate 100. The tip of the extending portion 301b is trapezoidal and, for example, assembling of the light source substrate 103b is improved by chamfering the corner portion of the extending portion 301b as shown in FIG. . Furthermore, it is necessary to design the shape of the extending portion 301b in consideration of the fact that light from the light source element of the light source substrate 103b spreads radially and repeats reflection and diffusion in the reflection diffusion sheet 304 and the optical sheet group 105. From the viewpoint of in-plane uniformity of backlight luminance, when the extending portion 301b protrudes forward from the light source substrate 103b and penetrates the reflection diffusion sheet 304, a shape that does not block the spread of light is preferable. FIG. 3D shows an example in which a notch 301d is formed from the front end to the center of the extending portion 301b so as not to block light from the light source element.
According to the first embodiment, since the heat sink can be mounted from the back surface of the BL case and screwed, the assemblability can be improved, and a thin and narrow frame backlight device can be provided.

[Second Embodiment]
Next, a second embodiment of the present invention will be described using FIG. 4 and FIG. FIG. 4 is a plan view showing a part of a direct type backlight device in which a plurality of light source substrates are arranged on the back surface of the display panel. FIG. 5 shows a detailed view (A) and a modified example (B) of part F in FIG.
First, the planar arrangement of the light source substrate 402 will be described with reference to FIG.
The light source substrate 402 is composed of a total of 24 vertical 3 × 8 horizontal, and is classified into the following three types according to the number of sides adjacent to the BL case 401.
14 light source substrates 402a whose long sides or short sides are close to the BL case 401
-Four light source boards 402b at the corners with two sides close to the BL case 401
-Six light source substrates 402c in the center where none of the sides is close to the BL case 401.
The light source substrates 402a, 402b, and 402c are only different in arrangement location, and are preferably the same shape from the viewpoint of common use of the substrates. Therefore, in order to allow these light source substrates to be placed at any location, notches 402d are formed at four corners of the substrate, respectively. As shown in FIG. 5A, the protruding portion 401b of the BL case 401 is inserted into the adjacent cutout portion 402d. The notch portions 402d formed in the adjacent light source substrates 402a and 402b each form a concave portion corresponding to the protruding portion 401b of the BL case 401 when viewed from the direction orthogonal to the light source substrate.

The modification shown in FIG. 5B shows a configuration in which the light source substrates 502a and 502b and the protruding portion 401b of the BL case 401 are arranged in the gap instead of providing the notch portions in the light source substrate. In this case, a space is required between adjacent light source substrates, but a process of excising a part of the substrate is not necessary.
According to the second embodiment, the same effect as that of the first embodiment can be obtained. At that time, it is only necessary to form the minimum necessary notch portion on the light source substrate, or it is not necessary to form the notch portion. .

  In addition, this invention is not limited to the said embodiment, It can implement with various forms. For example, in the example in which the configuration of FIG. 3B and the configuration of FIG. 4 are combined, the positioning of the light source substrate can be performed by the extending portion 301b, and the coupling of the BL case and the heat sink can be performed by the fastening portion 401a. .

100, 111, 200, 400 Radiating plate 101, 201, 401 BL case 101b, 111b, 401b Protruding part 101a, 401a Fastening part 103, 113, 203, 402, 502 Light source substrate 103d, 113d, 113e, 402d Notch part 103e Light source element 106,206 Display panel 301b Extension part 301d Notch part

Claims (6)

A display device including a display panel and a light source unit that emits light from the back side to the display panel,
A light source substrate having a plurality of light source elements;
A heat dissipating member disposed on the opposite side of the display panel with respect to the light source substrate;
A frame body that abuts from the side of the display panel on the outer peripheral edge of the heat dissipation member to form a side wall;
Among the frame body, wherein the heat-radiating member and the abutting portions are protrusions formed protruding on the light source substrate,
The protrusion is inserted into a notch formed in the light source substrate ;
A display device , wherein a screw for fastening the heat radiating member to the frame is screwed into a screw hole formed in the projecting portion through a through hole portion of the heat radiating member. . The display device according to claim 1 , wherein the protruding portion has a positioning portion with respect to the light source substrate. 3. The display device according to claim 1, wherein a width of the notch portion is smaller than a pitch between the light source elements including an outer size of the light source element. The notch has a display device according to any one of claims 1 to 3, characterized in that it is formed in a plurality of sides or corners of the light source substrate. The display device according to claim 2, wherein the positioning portion includes an extending portion extending toward the display panel. The display device according to claim 5, wherein a notch portion is formed in the extending portion.

Images