JP4545281B2 - Panel type LED display module - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a panel type LED display module for constructing, for example, a large-screen multi-color LED display device installed on an outer wall of an urban building, and in particular, realizes reduction in price, reduction in thickness, and ease of installation work. Regarding technology.
[0002]
[Prior art]
A high-performance full-color LED display device can be realized by practical use of a high-luminance blue LED (light-emitting diode). An LED display is often applied as a public display in a street or an airport because of its high brightness and relatively large screen.
[0003]
The large-screen LED display device has a basic design that constitutes a large screen having a required size by combining LED display modules having appropriately small dimensions vertically and horizontally. For example, 8 × 8 = 64 pixel lamps are arranged in a matrix at a constant pitch in one LED display module. One pixel lamp is an assembly of RGB three primary color LED lamps. For example, a large screen of 240 pixels in length and 320 pixels in width can be created by combining 1200 modules at a ratio of 30 vertical and 40 horizontal.
[0004]
A conventional LED display module of this type has a rectangular parallelepiped casing shape with a depth dimension that is nearly half of the front dimension in which LEDs are arranged in a matrix. This is due to the following internal structure. A large number of pixel lamps (LEDs) are mounted on a rectangular front printed wiring board. Several printed wiring boards are attached orthogonally to the back of this front printed wiring board, or another printed wiring board is attached in parallel to the back side of the front printed wiring board at an appropriate interval. . A display drive circuit and a power supply circuit (DC / DC converter) are mounted on these back printed wiring boards, and all of them are built in a rectangular parallelepiped casing having a large depth dimension.
[0005]
An appropriate frame structure for preparing a large screen is prepared, and a large number of LED display modules are arranged side by side in the frame. There are data signal and control signal terminals and power terminals on the back of the casing of each LED display module, and signal cables and power cables are systematically connected to the terminals on the back side.
[0006]
[Problems to be solved by the invention]
The conventional LED display module has a configuration in which a signal cable and a power cable are connected to the back side of the casing in addition to the large depth of the casing, so a large screen is configured by combining a number of modules. In some cases, the thickness of the screen structure is extremely large, and the overall weight is also increased. Therefore, it could not be easily attached to the building wall. It was necessary to construct a display installation structure on the wall of the building in advance, or to make a major change on the wall of the building. In addition, the module itself has a large number of parts and a large number of assembly steps, which increases the price, increases the weight, and makes it difficult to realize a highly reliable waterproof structure.
[0007]
The present invention has been made in view of the above-described conventional problems, and its object is to make the module itself a thin panel structure and to remarkably arrange the wiring on the back side when a large screen is formed by combining a large number of modules. An object of the present invention is to provide a panel type LED display module which can be made simple, can be easily installed on the wall of a building, can be configured at low cost with a reduced number of parts and assembly steps.
[0008]
[Means for Solving the Problems]
=== First Invention ===
The first invention is specified by the following items (1) to (7).
(1) A panel type LED display module for constructing a multi-color LED display device having a large screen by combining a large number of modules having the same configuration vertically and horizontally.
(2) In the front surface of the rectangular printed wiring board, m vertical and n horizontal pixel lamps are arranged in a matrix at a constant pitch p. One pixel lamp is an aggregate of three primary color LEDs, and the vertical dimension of the occupied space of one pixel lamp is a and the horizontal dimension is b. The lamp arrangement pitch p is set to be several times the pixel lamp dimensions a and b. The vertical dimension M and the horizontal dimension N of the printed wiring board are substantially expressed by the following equations.
M = (m−1) × p + a
N = (n−1) × p + b
(3) The printed wiring board is housed in a rectangular panel type case. The vertical and horizontal outer dimensions H and W of the panel type case are substantially expressed by the following equations.
H = m × p
W = n × p
(4) In the panel type case, the upper side of the printed wiring board is arranged as close as possible to the upper side of the panel type case, and between the lower side of the printed wiring board and the lower side of the panel type case Has an interval close to (pa).
(5) On the front surface of the printed wiring board, a plurality of integrated circuits for driving the pixel lamps are mounted at intervals between the pixel lamps. Two signal cables connected to these integrated circuits are drawn to the lower side of the printed wiring board. Connectors are attached to the ends of these signal cables.
(6) A cable / connector housing portion, which is a space for housing the signal cable with the connector, is formed in the space portion located below the lower side of the printed wiring board in the panel type case.
(7) When a large number of modules having the same configuration are combined vertically and horizontally, a transmission path for data signals for display and control signals is configured by interconnecting the connectors of the signal cables of adjacent modules.
[0009]
=== Second Invention ===
In the panel type LED display module according to the first aspect of the present invention, DC / DC converters, which are power supply circuits, are mounted in a distributed manner at intervals between the pixel lamps in front of the printed wiring board. A power cable with a connector for supplying input power to the converter is drawn out from the lower side of the printed wiring board to the cable / connector housing portion side.
[0010]
=== Third Invention ===
The panel-type LED display module according to the first or second invention, wherein the panel-type case includes an outer frame body that surrounds four sides of the printed wiring board, and the lower frame portion attached to the outer frame body. A cable / connector housing, a back cover that is inside the outer frame and covers the back side of the printed wiring board, and a front cover that is inside the outer frame and covers the front side of the printed wiring board; And the front cover is formed with a matrix of lamp windows for exposing the pixel lamps.
[0011]
=== Fourth Invention ===
A panel type LED display module according to a third aspect of the invention, wherein the outer frame body, the back cover, and the printed wiring board are fixedly integrated, and the front cover is screwed to the integrated object. The front of the cable / connector housing is closed by a small sub-cover separate from the front cover, and this sub-cover is detachably attached to the cable / connector housing by a snap-fit mechanism. It is characterized by being.
[0012]
=== Fifth Invention ===
The panel-type LED display module according to the first to fourth inventions, wherein the panel-type case includes a plurality of cylindrical bodies with screw insertion holes penetrating the printed wiring board from the front side to the back side. It is characterized by being formed individually.
[0013]
=== Sixth Invention ===
In the panel type LED display module according to the first to fifth inventions, a plastic waterproof piece embedded so as to surround the cable is integrally formed in the vicinity of the base of the signal cable. A waterproof resin which is positioned and fixed inside the lower side inner wall of the panel type case and filled with a certain thickness on the front side of the printed wiring board surrounds the inner periphery of the waterproof piece.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
A structure of a panel type LED display module according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The main components constituting this module are a printed wiring board 1 shown in FIG. 1 on which various circuit components are mounted, a case base 2 shown in FIG. 2 which is a base of a panel type case, and a back cover 3 shown in FIG. These are the inner frame 4 shown in FIG. 4, the front cover 5 shown in FIG. 5, and the sub-cover 6 shown in FIG. A module configured by combining these is shown in FIGS.
[0015]
=== Printed Wiring Board 1 and Mounted Component ===
The printed wiring board 1 is a square having a side of 225 mm, and 64 pixel lamps are arranged in an 8 × 8 matrix at a pitch of 30 mm on the front surface thereof. One pixel lamp is an aggregate of two red LED lamps 7r, one green LED lamp 7g, and one blue LED lamp 7b. These four lamps are arranged as close as possible in a 2 × 2 matrix, and the vertical dimension of the occupied space of the four aggregates (denoted as pixel lamps 7) falls within approximately 10 mm, and the horizontal dimension is approximately Fits within 12mm. Therefore, there is a large gap of approximately 20 mm in the vertical direction between the adjacent pixel lamps 7 and the pixel lamp 7, and a large gap of approximately 18 mm in the horizontal direction.
[0016]
A plurality of circuit elements are surface-mounted at large intervals between the pixel lamps 7 on the front surface of the printed wiring board 1, and a circuit system for driving the display of the pixel lamps 7 and a power supply circuit system including a DC / DC converter are provided. It is configured. Twelve QFP type integrated circuits 8 distributed on the wiring board 1 are the main elements of the display drive circuit system. Four DC / DC converters are mounted near both the left and right sides of the wiring board 1. One DC / DC converter includes one switching control SOP type integrated circuit 9, three inductors 10, one main switching transistor 11, one main capacitor 12, and the like. . In addition, a circuit system for transferring data to and from other modules when configuring a large screen display, a crystal oscillation circuit, and the like are mounted.
[0017]
An input signal cable 13, an output signal cable 14, and a power cable 15 are connected to the lower side of the printed wiring board 1. Waterproof connectors 13a, 14a and 15a are integrated at the ends of these cables. When a large screen display is configured by a large number of modules, a data transfer path that crosses each module is formed by connecting the input signal cable 13 of one module and the output signal cable 14 of the adjacent module by a connector. A display data signal and a control signal sent from the control device are distributed to each module. The connector 15a of the power cable 15 is connected to a predetermined DC power source.
[0018]
On the lower side of the printed wiring board 1, a notch 16 for passing the three cables 13, 14, 15 is formed. Further, a waterproof piece 17 for fixing the cable is attached to the base portion (portion located on the lower side of the wiring board 1) of each cable 13, 14, and 15 so as to surround the cable.
The printed wiring board 1 is formed with one large hole 38 near each of the four corners, and a large number of medium holes 39 and several small holes are formed in a dispersed manner.
[0019]
=== Case Base 2 and Back Cover 3 ===
The case base 2 is a plastic molded product, and as shown in FIG. 2, a rectangular outer frame 18, a skeleton 19 that connects the outer frame 18 vertically and horizontally at the back thereof, and a posture perpendicular to the panel surface The four large-diameter cylindrical bodies 20 for screw insertion formed integrally with the skeleton body 19 and the small-diameter screw fixing boss 21 (long boss) for fixing a tapping screw formed integrally with the skeleton body 19 in the same manner. And a short boss), and a positioning protrusion 22 formed integrally with the skeleton 19.
[0020]
The left side portion of the outer frame 18 has a double structure of the outer wall 23a and the inner wall 23b, and the lower side portion has a double structure of the outer wall 24a and the inner wall 24b. The upper side, the right side, the left side inner wall 23b, and the lower side inner wall 24b of the outer frame 18 form a square substrate housing space having a side of approximately 225 mm. The outer frame 18 has a square shape with sides of approximately 240 mm. The above-described cable / connector accommodating portion is the space portion (inner dimension is approximately 11 mm) between the outer wall 24a and the inner wall 24b on the lower side of the outer frame 18.
[0021]
The back cover 3 is an aluminum plate press-molded product. As shown in FIG. 3, a large number of holes are formed in a square plate slightly smaller than the printed wiring board 1, and unevenness is formed by a diaphragm. Yes. As shown in FIGS. 7 and 8, the back cover 3 is fitted into the outer frame 18 from the front side of the case base 2 and is fixed in contact with the skeleton 19. That is, a large number of holes are formed in the back cover 3 so as not to interfere with the cylindrical body 20, the screwing boss 21, and the positioning projection 22 that protrude from the skeleton body 19.
[0022]
=== Case Base 2 and Printed Wiring Board 1 ===
As shown in FIGS. 7 and 8, the printed wiring board 1 is fitted into the outer frame 18 of the case base 1 so as to overlap the back cover 3 with a slight gap. The printed wiring board 1 is also formed with a hole that does not interfere with the cylindrical body 20 protruding from the skeleton body 19 and the long screwing boss 21. The printed wiring board 1 abuts on a short screwing boss 21 and the wiring board 1 is fixed by screwing a tapping screw into the boss 21 from the front of the wiring board 1.
[0023]
Further, as described above, the waterproof pieces 17 are attached to the vicinity of the roots of the three cables 13, 14, 15 drawn to the lower side of the printed wiring board 1. The three cutout recesses 25 (FIG. 2) formed in the inner wall 24b on the lower side of the frame 18 are fitted. As a result, the positions where the cables 13, 14, and 15 are pulled out are restricted, and the waterproofness of the drawer portion is enhanced.
[0024]
=== Inner frame 4 and front cover 5 ===
The inner frame 4 is a plastic molded product, which is formed of a lattice of thin ribs as shown in FIG. 4 and is mounted so as to overlap the printed wiring board 1 fitted in the outer frame 18 of the case base 2. The grid of the inner frame 4 does not interfere with the pixel lamps 7 and circuit components mounted on the printed wiring board 1, and is formed with holes 26 through which the four cylindrical bodies 20 protruding from the skeleton 19 pass. .
[0025]
The front cover 5 is also a plastic molded product. As shown in FIG. 5, the outer shape of the front cover 5 is a rectangle having a vertical dimension of approximately 228 mm and a lateral dimension of approximately 240 mm, and the right side, the left side outer wall 23a, the upper side, and the lower side inner wall 24b of the outer frame 18 of the case base 2. The size exactly overlaps the top surface. On the front cover 5, 64 rectangular lamp windows 27 for exposing the pixel lamps 7 to the outside are arranged in rows and columns at a pitch of 30 mm. A cylindrical body 20 protruding from the skeleton body 19 is seen through the four large holes 28 formed in the front cover 5. The upper ends of the long screwing bosses 21 projecting from the skeleton body 19 are in contact directly below the four small holes 29 formed in the front cover 5, and a tapping screw is screwed into the front cover 5. Is fixed to the case base 2. On the upper part of each lamp window 27 in the front cover 5, a eaves 30 is formed for the purpose of preventing sunlight or the like from directly irradiating the pixel lamp 7.
[0026]
The space between the back cover 3 and the printed wiring board 1 assembled to the case base 2 is filled with epoxy resin or the like, and an epoxy with a certain thickness is provided on the front side of the printed wiring board 1 to which the internal frame 4 is assembled. Filled with resin. As a result, the inside of the panel type case in which the printed wiring board 1 is accommodated is almost completely waterproofed.
[0027]
=== Details of the mounting part of the waterproof piece 17 ===
The relationship between each of the three cables 13, 14, 15 and each waterproof piece 17 and the relationship between each waterproof piece 17 and each notch recess 25 formed in the lower inner wall 24 b of the outer frame 18 are the same. The cable 13 will be described as a representative based on FIG. 9 and FIG. As shown by a dotted line in FIG. 10, a metal ring 40 is attached to the outer periphery of a predetermined position of the cable 13 and fixed to the cable 13 by caulking. Is integrated around the cable 13. Accordingly, the joint surface of the cable 13 and the waterproof piece 17 is almost completely airtight, and the cable 13 and the metal ring 40 are caulked and the plastic waterproof piece 17 in which these are embedded has an integral structure. The piece 17 and the cable 13 do not shift (the metal ring 40 functions like an anchor).
[0028]
As shown in FIG. 9, the waterproof piece 17 has a substantially rectangular parallelepiped shape, and slits 41 are vertically formed on both side surfaces from the front side. Each notch recess 25 formed in the lower inner wall 24b of the outer frame 18 has a rectangular shape matching the front dimension of the waterproof piece 17, and fits into the slit 41 of the waterproof piece 17 on both sides of the notch. A vertical rib 42 having a shape to be inserted is formed. The waterproof piece 17 is formed with a screw insertion hole 43 penetrating vertically.
[0029]
As shown in FIG. 10, the opening by the notch recess 25 is filled with the waterproof piece 17 by fitting the waterproof piece 17 to the notch recess 25 of the lower inner wall 24 b of the outer frame body by engaging the slit 41 and the vertical rib 42. In this state, the screw insertion hole 43 of the waterproof piece 17 matches the screw fixing boss 21 formed integrally with the case base 2, and the tapping screw 44 is inserted into the hole 43 and twisted into the screw fixing boss 21. As a result, the waterproof piece 17 is fixed to the case base 2.
[0030]
In FIG. 10, what is expressed by fine dots is a waterproof resin (epoxy, silicon, weather-resistant urethane, etc.) filled with a substantially constant thickness on the front side of the printed wiring board 1. With the above structure, the drawn portions of the cables 13, 14, and 15 are almost completely waterproofed.
[0031]
=== Cable / Connector Housing and Sub-Cover 6 ===
As described above, the front surface of the cable / connector housing portion at the lower side of the case base 2 is not covered by the front cover 5. Covering this part is an elongate sub-cover 6 sized to fit this part. The sub cover 6 is detachably attached to the case base 2 by a snap fit mechanism. The sub cover 6 is also a plastic molded product, and elastic claws 31 are formed at three locations on the back surface of the sub cover 6 as shown in FIG. Correspondingly, engaging portions 32 are formed at three locations between the lower outer wall 24a and the inner wall 24b of the outer frame 18.
[0032]
=== Module connection installation ===
A large-screen display is constructed by connecting the necessary number of panel-type LED display modules of the present invention described above in detail, vertically and horizontally. In that case, it arrange | positions so that the outer frame bodies 18 of the case base 2 of each module may adhere. Then, the pitch of the pixel lamps 7 in one module is 30 mm, and the arrangement pitch of the pixel lamps 7 between adjacent modules is also 30 mm. Further, the above-described four cylindrical bodies 20 penetrate the panel-type case of one module from the front to the back. By inserting a screw into the cylindrical body 20 from the front side and screwing it into the installation base on the back side, each module can be installed on the installation base very easily.
[0033]
After installing a large number of modules, with the sub cover 6 removed, the input signal cable connector 13a and the output signal cable connector 14b of the adjacent modules are connected, and the power cable connector (not shown) is connected to the power cable connector 15a. Not connect). Then, after these connectors are stored in the space of the cable / connector storage portion of each module, the sub-cover 6 is put on and mounted.
[0034]
In this embodiment, the space between the outer wall 23a on the left side of the outer frame 18 and the inner wall 3b is not effectively used, but this portion is used as a connection storage space for the power cable, or a connection mechanism of the power feeding system. It is more desirable if it is used.
[0035]
【The invention's effect】
As described above in detail, according to the present invention, the multi-color LED display module itself for constituting a large screen display has a thin panel structure and can easily realize a highly reliable waterproof performance. The wiring on the back side when configuring a large screen by combining a large number of modules can be remarkably simplified, installation on the wall of the building is easy, and the number of parts and assembly man-hours constituting the module is small and inexpensive. Can be mass-produced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a printed wiring board according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of a case base in one embodiment of the present invention.
FIG. 3 is a configuration diagram of a back cover according to an embodiment of the present invention.
FIG. 4 is a configuration diagram of an inner frame body according to an embodiment of the present invention.
FIG. 5 is a configuration diagram of a front cover according to an embodiment of the present invention.
FIG. 6 is a configuration diagram of a sub-cover in one embodiment of the present invention.
FIG. 7 is a front view of a panel type LED display module according to an embodiment of the present invention.
FIG. 8 is a sectional view of the module.
FIG. 9 is an exploded perspective view showing details of a mounting portion of the waterproof piece in the module.
FIG. 10 is a plan view showing details of the waterproof piece mounting portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Printed wiring board 2 Case base | substrate 3 Back cover 4 Internal frame 5 Front cover 6 Sub cover 7 Pixel lamp 7r Red LED lamp 7g Green LED lamp 7b Blue LED lamp 8 QFP type integrated circuit 9 SOP type integrated circuit 10 Inductor 11 Main switching Transistor 12 Capacitor 13 Input signal cable 14 Output signal cable 15 Power cable 13a / 14a / 15a Waterproof connector 16 Notch 17 Waterproof piece 18 Outer frame 19 Skeletal body 20 Cylindrical body 21 Screwing boss 22 Positioning protrusion 23a Left side Outer wall 23b Inner wall 24 on the left side 24a Outer wall 24b on the lower side Inner wall 27 on the lower side 27 Lamp window 30 Hase 31 Elastic claw 32 Engagement part

Claims (6)

An invention that satisfies the following specific items (1) to (7).
(1) A panel-type LED display module for constructing a large-screen multi-color LED display device by combining a large number of modules having the same configuration vertically and horizontally.
(2) In the front of the rectangular printed wiring board, m vertical and n horizontal pixel lamps are arranged in a matrix at a constant pitch p. One pixel lamp is an aggregate of three primary color LEDs, and the vertical dimension of the occupied space of one pixel lamp is a and the horizontal dimension is b. The lamp arrangement pitch p is set to be several times the pixel lamp dimensions a and b. The vertical dimension M and the horizontal dimension N of the printed wiring board are approximately expressed by the following equations.
M = (m−1) × p + a
N = (n−1) × p + b
(3) The printed wiring board is housed in a rectangular panel type case. The vertical and horizontal outer dimensions H and W of the panel type case are substantially expressed by the following equations.
H = m × p
W = n × p
(4) In the panel type case, the upper side of the printed wiring board is arranged as close as possible to the upper side of the panel type case, and between the lower side of the printed wiring board and the lower side of the panel type case Has an interval close to (pa).
(5) On the front surface of the printed wiring board, a plurality of integrated circuits for driving the pixel lamps are mounted at intervals between the pixel lamps. Two signal cables connected to these integrated circuits are drawn out to the lower side of the printed wiring board. Connectors are attached to the ends of these signal cables.
(6) A cable / connector housing portion, which is a space for housing the signal cable with the connector, is formed in the space portion located below the lower side of the printed wiring board in the panel type case.
(7) When a large number of modules having the same configuration are combined vertically and horizontally, a transmission path for a display data signal and a control signal is configured by interconnecting the connectors of the signal cables of adjacent modules. 2. The panel type LED display module according to claim 1, wherein a DC / DC converter as a power supply circuit is mounted in a distributed manner in a space between the pixel lamps in front of the printed wiring board. A panel-type LED display module, wherein a power cable with a connector for supplying input power to the converter is drawn out from the lower side of the printed wiring board to the cable / connector housing side. The panel-type LED display module according to claim 1 or 2, wherein the panel-type case is attached to an outer frame body surrounding four sides of the printed wiring board and a lower side portion of the outer frame body. The cable / connector housing, a back cover that is inside the outer frame and covers the back side of the printed wiring board, and a front cover that is inside the outer frame and covers the front side of the printed wiring board A panel type LED display module, wherein the front cover is formed with a matrix of lamp windows for exposing the pixel lamps. 4. The panel-type LED display module according to claim 3, wherein the outer frame body, the back cover, and the printed wiring board are fixedly integrated, and the front cover is screwed to the integrated object. The front of the cable / connector housing is closed by a small sub-cover that is separate from the front cover, and this sub-cover is detachably attached to the cable / connector housing by a snap-fit mechanism. A panel-type LED display module. 5. The panel-type LED display module according to claim 1, wherein the panel-type case has a cylindrical body with a screw insertion hole penetrating the printed wiring board from the front side to the back side. A panel type LED display module, wherein a plurality of the LED are formed. The panel-type LED display module according to any one of claims 1 to 5, wherein a plastic waterproof piece embedded so as to surround the cable is integrally formed in a portion near the base of the signal cable. The piece is positioned and fixed along the inner wall of the lower side of the panel type case, and waterproof resin filled with a certain thickness on the front side of the printed wiring board surrounds the inner periphery of the waterproof piece. Panel type LED module.

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