JP2009222957A - Led display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an assembly structure which is improved so that the number of components, assembly man-hour and cost may be reduced regarding a light guide unit for guiding emission light of a light emitting diode (LED) chip to a display section. <P>SOLUTION: In the LED display device in which a plurality of LED chips 12 are arranged in array on a printed circuit board 3 disposed in a vertical posture in a box-shaped case with a display section in a front face, and in which a roughly L-shaped light guide member 5 is provided between the LED chip 12 and the display section, the light guide unit 4 is composed of two components of a light guide member aggregate 13 and a supporting plate 14, and unitedly molded by mutually connecting a plurality of light guide members corresponding to the array of the LED chip 12. Two sets of the light guide member aggregate 13 are arranged on the support plate 14, and in the support plate 14, positioning rib 14a, a light shield rib 14b of a corner section, a light shield wall 15 for preventing leak to surroundings, of light emitted from the LED chip 12, and an engaging pawl 16 of a snap fit system are unitedly formed, and the light guide unit 4 is assembled by interlocking and connecting them on a plate face of the printed circuit board 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an LED display device that is mounted on a programmable controller or the like and displays information on a front display portion thereof, and more particularly to an assembly structure thereof.

As the LED display device described above, a plurality of LED chips are arranged in an array on a printed circuit board that is housed in a box-shaped case having a display unit on the front surface and arranged in an upright posture, and the LED chips and A light guide member (lens) made of a transparent resin (for example, made of acrylic resin) having a light guide path formed in an approximately L shape between the display unit and a light output from each LED chip through the light guide member. Is known (see, for example, Patent Document 1), and its assembled structure is shown in FIGS.
In FIG. 7, 1 is a box-shaped case of a programmable controller comprising a front case 1a and a rear case 1b, 2 is a display unit arranged on the front surface of the front case 1a, and 3 is a plate surface along the side wall surface of the case 1. A printed circuit board 4 arranged in an upright position is a light guide unit for guiding emitted light from an LED chip (not shown) mounted on the printed circuit board 3 to the display unit 2 on the front surface of the case. A plurality of LED chips are arranged in an array on the side facing the light guide unit 4.
Further, as shown in FIG. 8, the light guide unit 4 includes a plurality of LED chips arranged between the LED chips and the display name plate of the display unit 2 in a one-to-one correspondence with the LED chips arranged in an array. The light guide member 5, the incident protrusion 6 and the objective protrusion 7 disposed on both the incident side and the emission side of the light guide member 5, and the light emitted from the LED chip by inserting the incident protrusion 6 leaks to the surroundings. A grid-shaped light-shielding partition plate 8 for preventing light, a grid-shaped mask 9 connected to the objective projection 7 and moving light emitted from each light guide member 5 forward, and a lens cover 10 covering the front surface of the mask 9 And a unit case 11 that contains these members and holds them in the assembly position. The mask 9 is provided with fixing ribs 9a and 9b as fixing legs, and the unit case 11 is provided with fixing ribs 11a. The fixing ribs 9a, 9b and 11a are formed in fixing holes formed on the plate surface of the printed circuit board 3. The light guide unit 4 is engaged and connected to the printed circuit board 3 by fitting. The detailed structure and function of each part are described in detail in Patent Document 1.
JP 2000-347605 A

By the way, the LED display device disclosed in Patent Document 1 has a complicated structure for assembling the light guide unit, a large number of parts and man-hours, and a mold for manufacturing various resin molded parts constituting the light guide unit. Cost is also required.
The present invention has been made in view of the above points, and provides an LED display device that has been improved by reviewing the above-described conventional light guide assembly structure to reduce the number of parts, the number of assembly steps, and the production cost. The purpose is to do.

In order to achieve the above object, according to the present invention, a plurality of printed circuit boards are housed in a box-shaped case having a display unit on the front surface and arranged in an upright posture along the plate surface along the side surface of the case. The LED chips are arranged in an array, and a light guide member made of a transparent resin having a light guide path bent in a substantially L shape is laid between the LED chip and the display unit. In the LED display device that guides the emitted light from the chip to the display unit,
A light guide member assembly formed by integrally molding tie bars between light guide members arranged corresponding to LED chips arranged in a horizontal row, and supporting the light guide member assembly in a horizontal posture After laying on the plate surface of the base plate and positioning and holding it, the support base plate is locked and connected to the printed circuit board (Claim 1), and specifically configured in the following manner To do.
(1) The said structure WHEREIN: The grid-shaped light-shielding wall part which prevents the leakage of the light radiate | emitted from an LED chip by inserting the incident end of each light guide member in the edge part of the support baseplate which opposes the board surface of a printed circuit board. Are integrally formed (claim 2).
(2) On the plate surface of the support base plate, positioning ribs that hold the light guide member assembly in place, and light between the adjacent light guide members covering the L-shaped corner portion of each light guide member A light shielding rib for preventing interference is formed upright.
(3) A snap-fit type engaging claw is provided at an end edge portion of the supporting base plate facing the printed board, and the supporting base plate is locked and connected to the printed board by the engaging claw.
(4) A plurality of LED chips are divided into upper and lower rows and arrayed on a printed circuit board, and two sets of light guide member assemblies molded corresponding to the LED chips in each row are arranged on the front and back sides of the support base plate. It is laid separately on both sides (Claim 5).

According to the above assembly structure, the assembly of the light guide unit that guides the emitted light of the LED chip mounted on the printed circuit board to the display unit disposed on the front surface of the box case becomes a single molded product. And a support base plate that is mounted and positioned at a fixed position by mounting this light guide assembly, which can significantly reduce the number of parts and assembly man-hours compared to the conventional structure. Cost reduction.
In addition, the support base plate includes a rib for positioning and holding the light guide member assembly at a fixed position, and a light shielding member that covers the L-shaped corner portion of each light guide member and prevents light interference between adjacent light guide members. The ribs, grid-shaped light-shielding walls, and snap-fit locking claws that are locked and connected to the printed circuit board are molded integrally, simplifying assembly workability and providing light guides that are adjacent to each other in terms of functionality. Light interference can be prevented by preventing light interference with the member.

Hereinafter, embodiments of the present invention will be described based on the examples shown in FIGS. 1 is an exploded perspective view of the light guide unit, FIG. 2 is a perspective view of the assembled state of the light guide unit, FIG. 3 is a plan view of FIG. 2, and FIG. 4 is an assembled state in which the light guide unit is locked and connected to the printed circuit board. FIG. 5 is a perspective view of the assembled state of FIG. 4, FIG. 6 is an exploded perspective view of the entire LED display device, and members corresponding to those of FIGS. It is attached.
In the LED display device of the illustrated embodiment, as shown in FIG. 1, the LED chips 12 are divided into two upper and lower rows and arrayed on the plate surface of the printed circuit board 3 (9 LED chips arranged in a horizontal row). Then, with respect to the array arrangement of the LED chips 12, a light guide unit for individually guiding and irradiating light emitted from each LED chip 12 toward the display unit 2 disposed on the front surface of the box-shaped case 1 of FIG. 4 includes two parts, two sets of light guide member assemblies 13 arranged vertically and a support base plate 14 that holds the two sets of light guide member assemblies 13 on the upper and lower surfaces and is engaged and connected to the printed circuit board 3. It is comprised with the assembly which consists of.
Here, the light guide member assembly 13 is a molded product of a transparent acrylic resin, and the incident end and the output end are on the same surface according to the number of array arrangements (9) of LED chips 12 mounted on the printed circuit board 3. The substantially L-shaped light guide members 5 (9 pieces) arranged so as to be lined up with each other are connected to each other by a tie bar (connecting bar) 13a to form a structure integrally molded. In addition, the light guide member 5 whose middle portion of the light guide path is bent in an L shape has its bent corner portion inclined at an angle of 45 °, and the light emitted from the LED chip 12 is reflected by the corner portion so as to be perpendicular. A light guide path is formed.

On the other hand, the support base plate 14 is a resin plate having an outer size corresponding to the light guide member assembly 13, and the upper and lower plate surfaces are fitted with the tie bar 13a and the light-emitting side end portions of the respective light guide members 5. Positioning ribs 14a for locking and holding the light guide member assembly 13 in place, and covering the inclined corner portions of the light guide member 5 from the inside and outside to prevent light from interfering between adjacent light guide members. The light shielding rib 14b is formed upright.
Further, a grid-like light shielding that prevents the light emitted from the LED chip 12 from leaking to the periphery by inserting the incident end of the light guide member 5 into the side edge of the support base plate 14 facing the printed circuit board 3. The wall 15 is integrally formed. Further, a snap-fit engagement claw 16 and a hook-shaped support leg 17 are formed at both ends of the light shielding wall portion 15 so as to protrude toward the printed circuit board 3. The printed circuit board 3 is inserted into an engagement hole formed in the hole and locked.
In order to assemble the light guide unit 4, first, the incident end of each light guide member 5 is inserted into a lattice-shaped light shielding wall portion 15 provided on the support base plate 14 to form two sets of light guide member assemblies 13. Overlaying the upper and lower surfaces of the support base plate 14, the light emission side end of each light guide member 5 and the tie bar portion 13 a are fitted between the positioning ribs 14 a erected on the support base plate 14 and held in place (holding). (See FIGS. 2 and 3). Next, engaging claw (snap fit) 16 and support legs 17 provided at both ends of the light shielding wall 15 are inserted into engaging holes drilled in the plate surface of the printed circuit board 3, and the light guide unit 4 is attached to the printed circuit board 3. Lock and connect (see FIGS. 4 and 5). In this assembled state, as shown in FIG. 4B, the incident-side end face of each light guide member 5 is close to and opposed to the LED chip 12, and its peripheral area is surrounded by a lattice-shaped light shielding wall portion 15.

The assembly of the printed circuit board 3 and the light guide unit 4 interconnected by the above procedure is assembled in the box-shaped case 1 of the programmable controller as shown in FIG. Configure the display device. The display unit 2 is printed with characters and numerical marks that are individually aligned with the light emitting end face of each light guide member 5.
In the above configuration, when the LED chip 12 is turned on, the light emitted from the LED chip leaks to the surroundings and enters the end surface of the light guide member 5 without interfering with each other, and then a bent corner formed in the middle portion thereof The light guide path is reflected in the right direction, the light guide path is changed to a right angle direction, and the display unit 2 is irradiated from the tip to illuminate the display characters and numerical marks on the front surface.
Moreover, in the light guide path, the bent corner portion of the light guide member 5 is covered from the inside and outside by the light shielding ribs 14b provided on the support base plate 14, so that the light guide member 5 is guided by diffuse reflection from the corner portion. There is no possibility that light leaking from the path enters the adjacent light guide member 5 to cause optical interference. Further, since the tie bars 13a that connect the light guide members 5 are formed in a direction perpendicular to the light guide path, they do not affect the light guide performance that goes straight.
The number of information points to be displayed on the display unit 2 is expanded by combining a plurality of sets of the light guide units 4 of the illustrated embodiment in which two sets of light guide member assemblies 13 are laid and assembled on both surfaces of the support base plate 14. It can also handle multipurpose specifications.

An exploded perspective view of a light guide unit according to an embodiment of the present invention The perspective view showing the assembly state of the light guide unit of FIG. Plan view of FIG. It is a figure showing the assembly state which latch-coupled the light guide unit of FIG. 2 to the printed circuit board, (a) is a top view, (b) is an expanded sectional view of the A section in (a). 4 is a perspective view. The exploded perspective view of the whole LED display device An exploded perspective view of a conventional LED display device mounted on a programmable controller 7 is an exploded perspective view showing the detailed structure of the light guide unit in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Box-shaped case 2 Display part 3 Printed circuit board 4 Light guide unit 5 Light guide member 12 LED chip 13 Light guide member aggregate | assembly 13a Tie bar 14 Supporting base plate 14a Positioning rib 14b Light shielding rib 15 Light shielding wall part 16 Engagement nail (snap fitting) )

Claims (5)

A plurality of LED chips are arranged in an array on a printed circuit board which is housed in a box-shaped case having a display unit on the front, and is placed in an upright position along the side of the case. A transparent resin light guide member having a light guide path bent in a substantially L shape is laid between the display unit and the display unit, and the emitted light from each LED chip is guided to the display unit through the light guide member. In the LED display device,
A light guide member assembly formed by integrally molding tie bars between light guide members arranged corresponding to LED chips arranged in a horizontal row, and supporting the light guide member assembly in a horizontal posture An LED display device, wherein the LED base plate is assembled by being laid on a plate surface of a base plate and positioned and held, and then the support base plate is locked and connected to the printed board. The LED display device according to claim 1, wherein an entrance end of each light guide member is inserted into an end portion of a support base plate facing the plate surface of the printed board to prevent leakage of light emitted from the LED chip. An LED display device in which the light shielding wall is integrally formed. 2. The LED display device according to claim 1, wherein a positioning rib for holding the light guide member assembly in a fixed position and an L-shaped corner portion of each light guide member are adjacent to the plate surface of the support base plate. An LED chip display device, characterized in that a light-blocking rib for preventing light interference with an optical member is formed upright. 2. The LED display device according to claim 1, wherein a snap-fit engagement claw is provided at an edge of the support base plate facing the printed circuit board, and the support base plate is locked and connected to the printed circuit board by the engagement claw. An LED display device characterized by that. 2. The LED display device according to claim 1, wherein a plurality of LED chips are divided into upper and lower rows and arrayed on a printed circuit board, and then molded in correspondence with the LED chips in each row. An LED display device characterized in that the body is laid separately on both the front and back sides of the support base plate.

Images