WO2007064069A1

WO2007064069A1 - A sign apparatus equipped with an easily replaceable and non-flat type sign unit and a differential light emission type backlight unit therefor

Info

Publication number: WO2007064069A1
Application number: PCT/KR2006/002760
Authority: WO
Inventors: Bumyoung Myoung
Original assignee: Hunatech Co., Ltd.
Priority date: 2005-12-02
Filing date: 2006-07-13
Publication date: 2007-06-07

Abstract

Disclosed herein are a slim energy-saving sign board apparatus and a differential light- emission backlight unit therefor. The sign member of the sign board apparatus can be expressed in a 3-dimensional fashion and replaced with other one, with the backlight unit remained in place. The apparatus includes a backlight unit and a sign board unit detachably combined with the backlight unit. In the backlight unit, the lamp light incident through the lateral side of a light guide plate is scattered and reflected by a light- scattering element formed in the bottom floor of the light guide plate and the scattered and reflected light is output through the top face of the light guide plate. The sign board unit is made of at least one of a transparent material and an opaque material. The light source of the backlight unit may adopt multiple straight-tube type lamp modules arranged in a row. In this case, an auxiliary lamp is provided between two adjacent lamp modules to eliminate a dark spot in-between. The backlight unit is designed to emit light uniformly over the entire top face thereof, or such that an area of certain shape can be brightened more brightly than the other remaining area.

Description

A SIGN APPARATUS EQUIPPED WITH AN EASILY REPLACEABLE AND NON-FLAT TYPE SIGN UNIT AND A DIFFERENTIAL LIGHT EMISSION TYPE BACKLIGHT UNIT

THEREFOR Technical Field

[1] The present invention relates to a sign board apparatus and a backlight unit therefor, more particularly, to a sign board apparatus in which a backlight is formed using a light guide plate and a sign member is combined with the backlight so as to enable to be replaced. Background Art

[2] There are various types of sign boards. Among them, a backlight type sign board is prevalent, which has a sign unit exhibiting a content to be advertised ("ad-content") and a backlight illuminating the sign unit from the rear side thereof so as to be well- recognized even at the night time. Recently, a vinyl material, called "Panaflex " produced by the company 3M, has mostly been employed in fabricating a backlight type sign board. In addition to this, colored tapes are cut and attached to construct the ad-contents of a sign board. Regarding this technique, the letters can be easily replaced, etc., but the ad-contents are expressed in a planar fashion, thereby leading to limited ways of expressions. A large fluorescent lamp is employed as a backlight source. Thus, in order to brighten the ad-contents, many fluorescent lamps are required, which result in an increase in the power consumption and complicated installation of securing and wiring each lamp.

[3] Further, the fluorescent backlight is disposed inside a roughly rectangular frame and an ad-content is attached to the front plate, which is hinged to the sidewall of the frame. Hence, if the ad-content needs to changed, it is impossible to replace only the portion to be changed in the ad-contents. Thus, the entire sign board must be detached and the ad-contents are to be changed as required. Otherwise, a separate new sign board must be fabricated. Even though only the ad-content is to be changed, the whole sign board structure including the backlight unit must be replaced, leading to waste of resources. In addition, generally the existing sign board structures are bulky and heavy and thus quite often a crane equipment is required to attach it to a wall structure and detach if form the wall. This attaching and detaching works cannot be easily done and are time and labor consuming.

[4] One way to express an ad-content in a 3-dimensional fashion is the neon sign. However, a sign board apparatus using neon signs consume excessive power, relative to the one using fluorescent lamps. The ad-contents such as letters and patterns are expressed by neon lamps, thereby necessitating a lot of efforts to work on the neon lamps. Furthermore, in case of sign board once fabricated using neon lamps, it is almost impossible to make a change to the contents expressed in the sign board, and there are some limitations in expressing various delicate contents.

[5] On the other hand, a sign board capable of replacing only the ad-contents has been proposed. Korean Utility Model Publication No. 20-0210644 discloses a sign board where its advertising phrase ("ad-phrase") can be replaced. That is, a guide groove for installing an ad-phrase plate is formed in the sign board frame. The ad-phrase plate is inserted into the guide groove. Alternatively a phrase frame having a phrase plate is re movably installed and a phrase film printed with an ad-phrase can be detachable attached inner side of the phrase plate. Korean Utility Model Registration No. 20-0301430 discloses a similar type of sign board entitled "a replaceable sign board." In this sign board structure, a base frame is installed in a building and remains there, but a phrase plate printed with an ad-phrase can be replace. However, the backlight of this sign board is structure such that a plurality of large fluorescent lamps is disposed at certain intervals right below the ad-phrase. Hence, in order to prevent optical stains, the fluorescent lamps need to be spaced apart from the ad-phrase plate by a certain distance. Hence, it has a limitation in decreasing the thickness of the sign board and consequently is not suitable for fabricating a slim sign board. In order to achieve a satisfactory luminance, the number of the fluorescent lamps to be installed must be increased, which leads to an excessive consumption of power. In addition, the ad- contents are expressed in a planar style. Thus, this cannot become a solution to the monotonousness in the existing planar sign boards.

[6] On the other hand, recently a light guide plate is being applied as the backlight of a sign board. In the provision of background light to a sign member, a certain specific portion of the sign board may be made brighter than the other portions thereof in order to perform an empathetic expression and thereby draw people's attention more efficiently. For this purpose, the backlight must enable to provide a differential background light. However, the conventional backlight unit using a light guide plate is designed mainly such that a uniform luminance can be achieved over the entire surface of the light guide plate to provide a uniform background light to the installed sign member.

Disclosure of Invention Technical Problem

[7] Accordingly, the present invention has been made in order to solve the above problems occurring in the prior art, and it is an object of the invention to provide a sign board apparatus which has a slim form and consumes less power, and can replace the sign member without having to detaching the backlight unit.

[8] Another object of the invention is to provide a sign board apparatus capable of expressing an advertising content in a 3-dimensional fashion, using various materials such as transparent fluorescent materials and opaque materials.

[9] A further object of the invention is to provide a sign board apparatus, in which the backlight is disposed in required regions only to selectively brighten, rather than other portions, thereby using the power efficiently and easily drawing people's attention.

[10] A yet another object of the invention is to provide a backlight apparatus for sign boards, using a light guide plate designed to emit a larger amount of light to a certain shape of area in its top surface, relative to the other remaining area thereof, thereby enabling to brightly empathize the selected area having the certain shape. Technical Solution

[11] In order to accomplish the above objects, according to one aspect of the invention, there is provided a sign board apparatus comprising a backlight unit and a sign board unit. The backlight unit includes a light guide plate having a light- scattering element provided in a bottom floor thereof and a light source having a lamp disposed in at least one lateral side of the light guide plate, the light of the lamp being provided inside of the light guide plate through the lateral side thereof, the light of the lamp incident through the lateral side of the light guide plate being scattered and reflected by the light- scattering element and emitted towards a top face of the light guide plate. The sign board unit includes a cover detachably combined with the backlight unit and cove ring the top face of the backlight unit, at least part of the cover area being opened or made of a transparent plate so as to pass the light provided by the backlight unit, and a 3-dimensional sign member inserted into the opening of the cover or attached to the transparent plate thereof, the sign member being made of a light-transmissible material passing light and generating a unique color, or an opaque material shielding light- transmission, or both of the transparent material and the opaque material. The 3-dimesional sign member exhibits an inherent color thereof in a 3-dimensional way by means of the backlight, and if necessary, only the sign board unit can be removed from the backlight unit and replaced with a new one, with the backlight unit remained in place.

[12] The backlight unit further includes a frame receiving and gripping the light guide plate and light source so as to be held close to the lateral side of the light guide plate, and, when necessary, to release and replace the light source only. In stead of proving such a frame, the cover may serve as a frame holding the light guide plate and the light source into a single body and simultaneously covering at least part of the top face of the backlight unit.

[13] The sign member is made of a light-transmissible material or a semi-transmissible material such as transparent or translucent acrylic resin plates, fluorescent acrylic plates, light- transmissible color films and the like. Various fluorescent acrylic resin plates generating a unique fluorescent color can be used to construct a sign member of various atmospheres. Further, an opaque metallic or non-metallic plate, or films or tapes can be used as a sign member. Preferably, these opaque materials may be combined with a transparent or semi-transparent material.

[14] Preferably, the sign member has a layered structure formed of multiple sign members having identical sizes or different sizes. In case of this structure, the light comes out from the side wall of the sign member so that the sign member can be recognized from the side thereof. Even in case of fabricating the sign member in a 3-dimension way, the backlight unit can be made to be a slim type having a thickness of no more than 30 mm, using an edge light type. Thus, the overall thickness of the sign board apparatus can be made thinner than the conventional ones.

[15] The material for the cover can be selected appropriately from transparent, semi- transparent, or opaque materials, according to the areas through which the backlight provided by the backlight unit is projected. In addition, the area in the cover where the sign member is placed is at least cut out correspondingly to the shape of the sign member, or made of a transparent material, thereby minimizing the backlight loss that is applied to the sign member. The sign member is inserted into the cut-out (opening) area or attached to the transparent material area to protrude three-dimensionally. At this time, the 3-dimensional sign member, inserted into the opening, is fixed using an adhesive so as not to create a gap in-between with an edge of the opening. The light from the light guide plate is applied to the sign member, which them generates a unique color according to its material properties.

[16] The light source of the sign board apparatus includes at least one lamp module. The lamp module includes a lamp unit, a lamp drive circuit and a lamp housing. The lamp unit has at least one lamp disposed along the lateral side of the light guide plate. The lamp emits light when a driving power is supplied. The lamp drive circuit provides the driving power to the lamp. The lamp housing has a light reflector trough and a tube member integrated with each other. The lamp housing has a first electrode terminal electrically connected with the lamp drive circuit and disposed in a certain position so as to be electrically connected from outside. The lamp drive circuit and the lamp are received in and integrally combined with the tube member and the light reflector trough respectively with an output terminal of the lamp drive circuit connected to an electrode of the lamp. The lamp housing further includes a second electrode terminal connected electrically in parallel with the first electrode terminal and exposed so as to enable to be externally connected. The first and second electrode terminals may be disposed at both lengthwise ends of the lamp housing. In this case, the light source includes a multiple number of the lamp modules of which total length is substantially equal to the whole length of light- incident lateral side of the light guide plate, and at least one connection jack electrically connecting the multiple lamp modules. The multiple lamp modules are linearly arranged in a row along the light-incident lateral side, and the connection jack is interposed between two adjacent lamp modules such that the first electrode terminal of the one of the two adjacent lamp modules is connected in parallel to the second electrode terminal of the other one of the two adjacent lamp modules.

[17] The lamp of the light source may employ a multiple number of straight tube type lamps arranged in a row along a lateral side of the light guide plate and each lamp is selected from the group consisting of a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL) and an external electrode fluorescent lamp (EEFL). By way of one example, in case of using a straight-tube type lamp such as a CCFL, the lamp module may further include a lamp holder gripping and fixing both ends of the straight-tube type lamp to the lamp housing; and an auxiliary lamp installed in a non- emission area at both end portions of the straight-tube type lamp where the lamp is not exposed. The straight-tube type lamp and the auxiliary lamp emit light together by an electric power supplied from the lamp drive circuit, thereby allowing the entire length of the lamp module to emit light.

[18] In some cases, the lateral side of the light guide plate is longer than the lamp module and a plurality of lamp modules need to be linearly connected one after another. In this case, the light source further includes one or more connection jacks electrically connecting the plurality of the lamp modules, of which total length is substantially equal to that of the lateral side of the light guide plate. The plurality of the lamp modules are linearly arranged in a row along the light-incident lateral side, and the connection jack is interposed between two adjacent lamp modules such that the first electrode terminal of the one of the two adjacent lamp modules is connected in parallel to the second electrode terminal of the other one of the two adjacent lamp modules.

[19] In case where the lamp is a straight-tube type lamp, and the lamp module further includes a lamp holder gripping and fixing both ends of the straight-tube type lamp to the lamp housing, the light source further includes an auxiliary lamp-integrated connection jack. The auxiliary lamp-integrated connection jack further includes one or more connection jack electrically connecting multiple lamp modules; and an auxiliary lamp integrated with the connection jack. The auxiliary lamp is automatically disposed between two adjacent lamp modules when connected by the connection jack, so that the straight- tube type lamp and the auxiliary lamp emit light together, without discontinuity between two adjacent lamp modules.

[20] In case of adopting a lamp module having the auxiliary lamp, the auxiliary lamp emits light in the connection area between two adjacent lamp modules, thereby not creating a dark spot over the entire length of the light source. Here, in case where the auxiliary lamp protrudes towards the light- incident side of the light guide plate further than the straight-tube type lamp, the light guide plate may be provided with a receiving space formed in a lateral side facing the auxiliary lamp so as to accommodate the protruded portion of the auxiliary lamp.

[21] In one embodiment, the backlight unit further includes a frame designed to receive and grip the light guide plate and the lamp module so as to be held close to a lateral side of the light guide plate, and, when necessary, to enable to release and replace the lamp module. In addition, the backlight unit may be further provided with a transparent water-proof member covering at least part of the light guide plate and the light source to prevent moisture from penetrating into inside of the light source.

[22] In some cases, light from the backlight unit is concentrated on the sign member to brightly empathize the sign member among the entire sign board apparatus. For this purpose, the light output region can be configured to conform to the shape of a sign member. That is, the light- scattering element is disposed, among the entire bottom floor of the light guide plate, only in portions corresponding to the opening of the cover or the transparent base plate, such that light is intensively emitted from the light- scattering element region. Alternatively, in case where the opening areas and the transparent base plate areas are distributed over multiple locations, the backlight unit is disposed for each opening area and transparent base plate, or the opening area and the transparent base plate areas are grouped based on spatial closeness thereof and each group is provided with the backlight unit.

[23] For the purpose of further diversification of expressions, an advertisement film can be utilized, along with the 3-dimensional sign member. That is, the sign board apparatus may further comprise an advertisement film disposed and fixed between the sign board unit and the backlight unit, or on top face of the sign board unit so as not to veil the 3-dimensional sign member, the advertisement film being printed with a content to be expressed.

[24] According to another aspect of the invention, there is provided a backlight apparatus capable of differential light-emission. The backlight apparatus comprises: a light guide plate having a light- scattering element provided only in a certain portion of the bottom floor thereof; a light source including one or more lamp and a power supply for lighting the lamp, the light generated by the lamp being incident through at least one lateral side of the light guide plate; and a frame for gripping and supporting the light guide plate and the light source so as for the light source to be held close to a lateral side of the light guide plate Light introduced through the lateral side of the light guide plate is scattered mainly in the certain portion such that, among the entire top face of the light guide plate, a portion facing the certain portion is brightened more brightly than the other remaining portion thereof. [25] In the above backlight apparatus, the light guide plate is made of a transparent acrylic resin plate material and the light- scattering element is formed of numerous fine depressions formed only in the certain portion to extent to be invisible with naked eyes. Preferably, a light reflector film is further attached to the bottom floor of the light guide plate. The light introduced through the lateral side of the light guide plate is mostly scattered and reflected in the fine depressions area and the backlight comes out mostly from the fine depressions area (i.e., the certain area of the light guide plate).

Advantageous Effects

[26] According to the sign board apparatus of invention, the contents in the sign board are expressed in a 3-D fashion to provide a wider viewing angle. The sign board apparatus of the invention provides for a simplified structure, relatively to conventional 3-D sign boards (e.g., neon signs or the like), and, in view of the previously mentioned various advantages, is superior to the conventional techniques in many respects.

[27] The cold cathode fluorescent lamp or LED used as the light source consumes relatively less power, thereby significantly reducing the power consumption of the sign board apparatus.

[28] In addition, the backlight can be concentrated in a desired portion only, not the entire sign board apparatus, thereby enabling an efficient use of power and also drawing people's attention effectively. In particular, the backlight is configured to be emitted differentially over the entire region of the light guide plate. Thus, comparing to the conventional backlight device generating the same amount of light, at least the light emitting region can achieve much higher luminance. Such a backlight apparatus can be used to provide a sign board apparatus capable of creating a variety of expressions and atmospheres.

[29] Furthermore, the invention adopts an edge type backlight configuration using a light guide plate to thus enable a slim type backlight and sign board apparatus. Brief Description of the Drawings

[30] Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:

[31] Fig. 1 is a perspective view of a sign board apparatus according to the first embodiment of the invention;

[32] Fig. 2 is a cross sectional view taken along the line A-A in Fig. 1;

[33] Fig. 3 is a cross sectional view showing a modification of the sign board apparatus of Fig. 1;

[34] Figs. 4 to 6 show methods for fastening a sign member;

[35] Figs. 7 to 11 show exemplary photographs of sign board apparatuses manufactured according to the first embodiment of the invention; [36] Figs. 12 to 14 are perspective views of a sign board apparatus according to the second embodiment of the invention;

[37] Fig. 15 is a cross sectional view taken along the line B-B in Fig. 12;

[38] Fig. 16 is a cross sectional view showing a modification of the sign board apparatus of Fig. 12; [39] Figs. 17 to 19 are exemplary photographs of sign board apparatuses fabricated according to the second embodiment of the invention: [40] Fig. 20 is an exploded perspective view of a sign board apparatus according to the third embodiment of the invention;

[41] Fig. 21 illustrates assembling of the sign board apparatus of third embodiment;

[42] Fig. 22 is a cross sectional view taken along the line C-C in Fig. 20;

[43] Fig. 23 is a cross sectional view showing a modification of the sign board apparatus of Fig. 22; [44] Fig. 24 is a cross sectional view showing another modification of the sign board apparatus of Fig. 22; [45] Fig. 25 is an exploded perspective view of a lamp module adopted in the third embodiment of the invention;

[46] Fig. 26 shows a connection of multiple lamp modules of Fig. 25;

[47] Fig. 27 is an exploded perspective view of a sign board apparatus according to the fourth embodiment of the invention; [48] Figs. 28 and 29 are exploded perspective views showing variations of the fourth embodiment; [49] Fig. 30 is an exploded perspective view of a sign board apparatus according to the fifth embodiment of the invention;

[50] Fig. 31 shows an assembled view of the sign board apparatus of Fig. 30.

[51] Fig. 32 is an exploded perspective view of a lamp module using an auxiliary light source to eliminate the non-emitting area;

[52] Fig. 33 shows a connection of multiple lamp modules of Fig. 32;

[53] Fig. 34 is an enlarged view of the connection area of two lamp modules to explain operation of the auxiliary light source; [54] Figs. 35 and 36 are an exploded perspective view and an assembled perspective view respectively showing the connection of two lamp modules using a connection jack integrated with an auxiliary light source; and

[55] Fig. 37 is a cross sectional view taken along the line D-D in Fig. 36.

Mode for the Invention

[56] Hereafter, exemplary embodiments of the invention will be explained, with reference to the accompanying drawings.

[57] (1) First embodiment

[58] Fig. 1 is a perspective view of a sign board apparatus according to the first embodiment of the invention, where the sign board apparatus is denoted generally by 100. The sign board apparatus 100 includes generally two components. One is a sign board unit containing contents to be expressed in the sign board and the other one is a backlight unit providing backlight to the sign board unit.

[59] The backlight unit is formed of an edge type using a light guide plate 140.

Specifically, the backlight unit includes a light guide plate 140 having a light- scattering element formed in its bottom floor, at least one lamp 150 providing light to the inside of the light guide plate, and a lamp drive circuit 160 providing a power necessary for driving the lamp 150. The light guide plate 140 is configured such that light incident through the side thereof is scattered and reflected by the light-scattering element and output through the top face of the light guide plate. The lamp 150 is disposed close to at least one side of the light guide plate 140 or both opposing sides thereof. The light guide plate 140 is made of a plate material of transparent acrylic resin. The light- scattering element formed in the bottom floor of the light guide plate 140 is formed of any one of well-known techniques, which for example include a fine depression pattern made up of numerous fine depressions to the extent to be invisible with naked eyes, multiple dot ink pattern, and a V-cut pattern made up of multiple V- shape grooves. The fine depression pattern is formed preferably of a gradation pattern in order to achieve uniform luminance. In addition, the lamp drive circuit 160 is disposed on the bottom floor or on the side of the light guide plate. The backlight unit further includes a frame 170. The frame 170 receives and holds the light guide plate 140, the lamp 170 and the lamp drive circuit 160 so as to form one integral body or unit. The backlight unit is formed of an edge type and thus can be made of a slim form having a thickness of no more than 30 mm. This thin thickness can result in a uniform luminance over the entire surface of the light guide plate 140.

[60] The sign board unit is provided with a cup-shaped cover, which covers the edge portion of the top surface of the light guide plate 140 and the lamp 150, and wraps around the side face of the light guide plate. The cover 130 has an opening formed at its center. Preferably, the sign board unit may further include an inner cover plate 120 covering the entire central opening of the cover, and made of a transparent or translucent material so as to pass the light coming from the light guide plate 140. The inner cover plate 120 is bonded to the cover along around the opening, for example, using an adhesive to thereby provide a water-proof function. The inner cover plate 120 has a function of passing the light of light guide plate 140 and also serves as a bas plate on which a sign member 110 is attached. Thus, it may be attached to the outer face of the cover, as well as the inner face thereof. This is applied to other embodiment which will be explained hereafter. An adhesive to attach the sign member 110 to the cover 130 may employ a transparent adhesive such as a transparent tape or a transparent bond, but not limited thereto.

[61] The sign board unit further includes a sign member 110, which displays an advertising content (hereinafter, referred to as an "ad-content"). The sign member 110 is combined to the cover 130, for example, joined to the top surface of the cover or inserted into a cut-out portion of the cover 130. The sign member 110 is disposed on the inner cover plate 120, which serves as a base plate. The sign member 110 is formed as a three-dimensional form using at least one of transparent, translucent and opaque materials. The sign member 110 is disposed on the light-emitting region of the light guide plate so as to receive the light from the light guide plate and then emit the light, or shield the light from the light guide plate, thereby expressing a specific ad-content. The sign member 110 is needed to create a variety of expressions and atmospheres, using light. Hence, the sign member may be made of either one of transparent or translucent materials, or appropriate combinations thereof when necessary, such as a transparent acrylic plate having a good optical expressiveness, a fluorescent acrylic plate of various colors, and a transparent color film of various colors. In addition, for further variety of expressions of the sign member 110, for example, a metallic or non- metallic opaque material having various colors can be used together. For the purpose of three-dimensional expression, the sign member 110 is formed of a stacked structure of multiple layers of sign members. By way of example, various types of transparent, translucent or opaque materials are used to implement desired ad-contents having a variety of sizes and shapes, which then can be stacked to fabricate a sign member 110, thereby enabling to produce various atmospheres and appearances of three-dimensional. As more specific examples, at least one of a transparent acrylic plate material and a fluorescent acrylic plate material can be used to make the shapes of desired alphabets having same sizes or having different sizes but similar contours, and then stack these to form a stacked structure of sign member. Alternatively, at least one of a transparent acrylic plate material and a fluorescent acrylic plate material, and an opaque plate material are used to make the shapes of desired alphabets having same sizes or having different sizes but similar contours, and then stack these to form a stacked structure of sign member.

[62] The sign board unit is combined with a backlight unit using for example a screw

165. Thus, when necessary, the screw can be released to replace the sign board unit only. In this way, the sign board apparatus 100 of invention, as described above, is configured such that light provided from the light guide plate 140 is used to make the three-dimensional sign member 110 to exhibit its inherent color in a three-dimensional fashion, and simultaneously when required, only the sign board unit can be detached from the backlight unit and replaced with other one.

[63] Figs. 1 and 2 show a sign board unit expressing an English alphabet letter H. The sign member indicating the letter H is structured in such a way that a transparent acryl 116, a fluorescent acryl 114 and an opaque material 112 are stacked in sequence on an inner cover plate 120. The transparent acryl 116 and the fluorescent acryl 114 serve as a color-emitting layer, which receives light from the light guide plate 140 and emits its own colors. As shown in Fig. 3, if these two layers are switched, another different atmosphere can be created. In addition, the opaque material 112 covers part of the two acrylic materials 114 and 116 to allow for a variety of expressive patterns.

[64] Figs. 4 to 6 illustrate several ways for securing the sign member 110. One way to combine the inner cover plate 120 serving as a water-proof transparent window and a base plate with the materials constituting the sign member 110 is shown in Fig. 4, which uses a transparent adhesive at portions required to minimize the light loss. The light passes through between the inner cover plate 120 and the transparent acryl 116 and between the transparent acryl 116 and the fluorescent acryl 114. Hence, it is preferable to use a transparent adhesive such as a transparent acrylic adhesive or a transparent double-side adhesive. The light is shielded between the metallic or non- metallic opaque material 112 and the fluorescent acryl 114 or the transparent acryl 116, where a transparent adhesive is not necessary, a double-side adhesive or a resin adhesive may be applied. In addition, the light does not pass through the portions where the cap ( -shape) cover 130 and the inner cover plate 1120 are overlapped, and hence a double-side adhesive or a resin bond can be applied thereto without any concern. As shown in Fig. 5, the inner cover plate 120 and the sign member 110 may be secured to each other, using a plurality of screws 110a, 118b and 118c. In addition, as illustrated in Fig. 6, the -shape cover 130 may be manufactured to have an opening conforming to the lowest layer of the sign member 110 (the transparent acryl 116 in Fig. 6). The transparent acryl 116 is inserted into the opening of the cover 130 and then the gap between the transparent acryl 116 and the cover 130 is tightly sealed with an adhesive such as a silicon sealant to thereby achieve bonding and water-proofing simultaneously. In this embodiment, the transparent acryl 116 serves as a base plate and a water-proof plate simultaneously. Hence, the inner cover plate 120 is not necessarily required.

[65] With the above first embodiment of the invention, an English letter sign board can be constructed conveniently. For this purpose, first, multiple sign members are manufactured for each of the English alphabetic letters. If various types of materials are used to fabricate the sign member, each alphabet letter can be expressed in a variety of patterns and fashions. For example, it includes transparent or translucent materials such as transparent acrylic resin plates and fluorescent acrylic resin plates having various colors, and opaque materials such as metallic or non-metallic opaque plates or films. These materials having various colors and optical properties can be used to fabricate each alphabet letter so as to have various different sizes. Then they can be combined appropriately and desirably to express the alphabet letter in a variety of ways. That is, the sign member can be configured to receive light from the backlight unit and emit its own unique colored-light or to shield the light, to thereby express a single alphabet letter in various different fashions. When constructing a sign member of a certain alphabet, the transparent material is fabricated to have a larger size and the opaque material is made to have a smaller size, but for both to have similar contours, such that the smaller opaque sign member can be disposed within the larger transparent sign member. Alternatively, the transparent materials may be fabricated to have different sizes and then a smaller one can be overlapped on a larger one, etc. In this way, sign members made of various materials can be stacked to express one alphabet letter.

[66] Figs., 7 to 11 are photographs showing sign board apparatuses manufactured according to the first embodiment of the invention. In Figs. 7 and 8, the opening of the cover 130 is made larger than the letters to be expressed, regardless of the types of the letters. In Figs. 9 to 11, the opening of the cover 130 is machined so as to conform to the shapes of letters to be expressed. According to whether or not an opaque material 120 is employed, the entire letter emits light (Figs. 8 and 9), or part of the letter does not emit light, but instead is expressed in a different color (Figs. 7, 10 and 11). Specifically, in Fig. 7, a first layer letter ¹H' made of a black opaque material and a second layer letter ¹H' having a larger size and made of a yellow fluorescent acryl are stacked in sequence on a rectangular white-light background. In Fig. 8, stacked on the same background are letters ¹H' having the same size and made of a transparent acryl and a pink fluorescent acryl respectively. In case of Fig. 9, stacked on a white-light letter ¹H' background are letters ¹H' made of a transparent acryl and a yellow fluorescent acryl respectively so as to have a smaller size than the background. In Fig. 10, stacked on a white-light letter ¹H' background is a first layer letter ¹H' made of a transparent acryl so as to have a size equal to or greater than the background, and further stacked thereon are a second layer letter ¹H' and third layer letter ¹H' made of a transparent acryl and a red opaque material respectively so as to have a smaller size than the first layer. Fig. 11 has the same background and first layer as in Fig. 10. The second layer is a letter ¹H' made of a yellow fluorescent acryl so as to have the same size as the first layer and a third layer stacked on the second layer is a letter ¹H' made of a black metallic plate so as to have a smaller size than the second layer. In Figs. 7 and 8, the letter portion and the background portion emit together their own unique lights to express the letter ¹H'. In case of Figs. 9 to 11, only the letter portion emits its own unique light to express the letter ¹H'.

[67]

[68] (2) Second embodiment

[69] Figs. 12 to 14 shows assembled sign board apparatuses 100-1, 100-2 and 100-3 according to the second embodiment of the invention. Fig. 15 is a sectional view taken along the ling B-B in Fig. 12. These sign board apparatuses 100-1, 100-2 and 100-3 are different from that 100 of Fig. 1, in that a base plate 135 for resting a sign member 110 thereon is employed, instead of the cover 130 and the inner cover plate 120. The backlight unit is structure such that a light guide plate 140 and a lamp 150 and a lamp drive circuit 160 disposed at the side thereof are received in a frame 170 and secured therein. Here, the frame 170 is configured to open the top face of the light guide plate, similar to the cover 130 in the first embodiment. The base plate 135 may be installed spaced apart from the frame 170, for example, by disposing a support pole in-between using a screw, as shown in Fig. 15. As shown in Fig. 16, alternatively, it may be combined with the top face of the frame 170 directly, without a support pole. In case of Fig. 16, for the purpose of water-proofing, it is preferable that the base plate 135 and the top face of the frame 170 are tightly bonded to each other so that external moisture cannot smear thereinto. In Fig. 15, in order to provide water-proofing, preferably, a water-proof transparent base plate 139 or film is further installed so as to seal the opening area of the frame 170, thereby preventing moisture from smearing into the inside of the frame 170. The base plate 135 may be made of a transparent material ca pable of passing the light of light guide plate 140. For example, a fluorescent acrylic plate, emitting its unique fluorescent light when receiving light, can be used to provide an excellent background for a letter intended to express.

[70] Figs. 17 to 19 are photographs showing sign board apparatuses manufactured according to the second embodiment. According to Fig. 12, the frame 170 in Fig. 17 is provided at its top face with an opening having the form of letter ¹H' through which light comes out from the light guide plate 140, and a red fluorescent rectangular acryl is covered on top of the opening. In case of Fig. 18, a transparent acryl mad into a letter ¹H' shape is disposed above the fluorescent acryl of Fig. 17. In Fig. 19, disposed on the fluorescent acryl of Fig. 17 is an opaque metallic plate of letter ¹H', which is machined into a letter ¹H' smaller than the opening area of letter ¹H'.

[71] The previous embodiments 1 and 2 have been explained illustrating an English alphabet ¹H', but the types of letters to be expressed are not particularly limited. In addition, for example, one way of constructing a sign board expressing a word "HUNATECH" is that the above-described sign board apparatus is fabricated separately for each letter of the word and they are disposed adjacently to constitute the word. As an alternative, the sign board apparatus may be made in a single piece so as to express the eight letters of the word.

[72]

[73] (3) Third embodiment

[74] Figs. 20 to 22 show a sign board apparatus 200 according to the third embodiment of the invention. In particular, Fig. 22 is a cross sectional view taken along the line C- C in Fig. 21. This embodiment is similar to the two previous ones in that a lamp 150 is disposed at the side of the light guide plate 140 to provide an edge type backlight unit 260. However, the lamp drive circuit 160 supplying the power necessary for lighting the lamp 150 is disposed rearwards of the lamp 150, not the bottom floor of the light guide plate 140 (right side of the light guide plate 140 in the figures). For purpose of this arrangement, the frame 180 is structured so as to provide a space to accommodate the lamp 150 and the lamp drive circuit 160 along the side of the light guide plate 140 while surrounding the sides of the light guide plate 140.

[75] Preferably, the lamp 150 and the lamp drive circuit 160 are integrated into a modular structure for the purposes of convenient installation and maintenance. For this purpose, a lamp housing 190 is employed to receive the lamp 150 and the lamp drive circuit 160 together to thereby construct an integrated lamp module. The lamp module is housed inside of the accommodation space of the frame 180. The sign board apparatus 200 of Fig. 20 employs four lamp modules 250-1, 250-2, 250-3 and 250-4. The accommodation space of the frame 180 provided along each of opposing sides of the light guide plate 140 receives two lamp modules respectively.

[76] Fig. 25 is an exploded view showing details of the lamp module 250. The lamp housing 190 has an integrated structure of a light-reflector trough 192a and a tube member 192b combined thereto. The lamp housing 190 is a rod type having a length slightly longer than the lamp 150. The lamp drive circuit 160 is made up of a circuit board 160 and circuit elements mounted o\thereon. An output terminal of the lamp drive circuit 160 is connected to the electrode of the lamp 150 through an electric wire 167. At this state, the lamp drive circuit 160 and the lamp 150 are received inside of the tube member 192b and the light reflector trough 192a respectively of the lamp housing 190. Both ends of the lamp housing 190 are closed with a lid plug 194. A lamp holder 152a, 152b made of elastic rubber is inserted into a small through-hole provided in the end portions of the lid plug 194 and the light-reflector trough 192a. Both end portions of the lamp 150 are inserted into through-holes formed inside of the lamp holders 152a and 152b to be elastically supported therein. The lid plug 194 is provided with electrode terminals 194a and 194b, which are electrically connected with electrode terminals 164a and 164b of the lamp drive circuit 160. This electrode terminal 194a, 194b is exposed so as to enable to be externally coupled with an electric power plug 191, a connection jack 193a or a connection cable 193b.

[77] In this way, the lamp 150 and the lamp housing 190 and other elements associated therewith are modularized into an integrated piece by means of the lamp housing 190. Thus, it can be easily mounted in the accommodation space of the frame 180 and provides for a simple and convenient maintenance. In particular, failure of a sign board apparatus is usually caused from the power supply and lamp. Hence, using this modular structure, a certain concerned module such as a broken module can only be replaced, without having to detach the entire sign board apparatus, when in failure or trouble.

[78] In the case where the lamp 150 employs a cold cathode fluorescent lamp, it is preferable to take a measure to facilitate lighting of the lamp at a lower temperature outside in the winter. For this purpose, an electrode heater 196a, 196b is provided to rapidly heat up the electrode lead wire of the cold cathode fluorescent lamp to increase the ambient temperature around it. The lamp drive circuit 160 further includes a circuit for supplying an electric power necessary for heating two electrode plates of the electrode heater 196a, 196b for a certain length of time, before supplying a starting voltage to the lamp. This electrode heater 196a, 196b is made up of a heating material plate made of fine ceramic material and electrode plates closely adhered to both faces thereof, and contacts the electrode lead wire of the fluorescent lamp so as to be capable of thermal conduction. If an electric power is applied to both electrode plates of the electrode heater, the heating material plate is rapidly heated and the heat is transferred to the electrode lead wire of the fluorescent lamp 150.

[79] The lamp module of the invention is configured such that multiple modules are connected to form a light source having a certain desired length. Fig. 26 shows the lamp module of the invention. A first lamp module 250- 1 and a second lamp module 250-2 are linearly connected by means of a connection jack 193a interposed in- between. The first electrode terminal 194a of the first lamp module 250-1 is coupled to a power plug 191, which is connected with an external power supply. The connection jack 193a is formed of a body made of an insulator and houses a connection terminal disposed at a desired position of the body. The body of the connection jack 193a is structured such that roughly half of the connection jack is snugly fitted into a hole formed in each of the facing led plugs of two lamp modules 250-1 and 250-2. Thus, the connection terminal is electrically coupled to the electrode terminal 194a, 194b. Where the lamp module is disposed at both opposing sides of the light guide plate 140, a connection cable 193b can be used to connect the two with each other. That is, the connection jack 193a allows multiple lamp modules to be linearly connected so as to conform to the side length of the light guide plate, thereby providing a parallel connection. In this way, the lamp modules 250- 1 and 250-2 provides for a good lengthwise expandability and thus can be applied flexibly to various lengths of sign board apparatus.

[80] Here, when two lamp modules 250-1 and 250-2 are connected through the connection jack 193a, two lid plugs 194-1 and 194-2 closing both ends of the module and two lamp holders 152-1 and 152-2 abut against each other. Thus, two lamps 150-1 and 150-2 create a discontinuity T in-between, which does not emit light. Hence, in the light guide plate 140, the front area of the two lamps 150-1 and 150-2 becomes brighter, relatively to the front area of the light guide plate corresponding to the discontinuity T. Difference in the brightness of the two areas is significant to the extent to be recognized by people, thereby appearing as an optical stain.

[81] Therefore, preferably an auxiliary lamp is provided to both ends of the lamp module

250-1, 250-2, to thereby remove the dark area of discontinuity T. Fig. 33 illustrates an auxiliary lamp 151 (151-la and 151- Ib, or 151-2a and 151-2b) further installed on the lamp holder 151-1, 151-2. If the above-configured lamp modules 250-1 and 250-2 are connected using a connection jack 193a, the discontinuity T between the first and second lamps 150-1 and 150-2 can be covered by the auxiliary lamps 151- Ib and 151-2b. That is, the first lamp 150-1, the auxiliary lamps 151- Ib and 151-2a, and the second lamp 150-2 are continuously and linearly arranged to eliminate the optical stain, which may occur in the front area of the discontinuity T. A preferred example for the auxiliary lamp 151 is a light emitting diode (LED). Further, considering the luminance of the first and second lamps 150-1 and 150-2, it is preferable to select an auxiliary lamp 151 so as to have the same as or similar luminance to that of the lamps. In addition, for the same purpose, the number of the auxiliary lamps 151 to be installed in the discontinuity T can be determined appropriately according to the desired brightness.

[82] The auxiliary lamp may be attached to the front side of the lid plug 194-1, 194-2 or the lamp holder 152-1, 152-2 of the lamp module 250-1, 250-2, using various methods. The rear side of the base plate 153 of the auxiliary lamp 150 is applied with an adhesive and attached to the front face of the lamp holder 152-1, 152-2. Although not illustrated here, alternatively the base plate 153 of the auxiliary lamp 151 may be fixed to the lid plug 194-1, 194-2 or the lamp holder 152-1, 152-2, using a small screw or bolt. [83] In case where the auxiliary lamp 151 is installed, it may protrude slightly forwards relative to the first and second lamp 150-1, 150-2. In this case, as shown in Fig. 33, the side portion of the light guide plate 160, facing the auxiliary lamp 151, can be slightly removed to form a receiving space 142 for accommodating the auxiliary lamp 151.

[84] The auxiliary lamp 151 is connected to the terminal of the circuit board 162 of the lamp drive circuit 160 through an electric wire 155 and supplied with driving power. This driving power is configured to be turned on and off, synchronized with the driving power being supplied to the lamps 150.

[85] Figs. 35 to 37 shows a connection of two lamp modules 250-1, 250-2 using a connection jack 270 integrated with an auxiliary lamp. The auxiliary lamp 276a, 276b is formed integrally with a connection jack body 272. Specifically, disposed inside of the connection jack body 272 is an electrode terminal 272 to be connected with the electrode terminal 194a, 194b of the two lamp modules 250-1 and 250-2. The connection jack is provided with a jack arm 274 extended outwards from the center portion of the outer face of the jack body 272. A bracket 275 is attached to the end of the jack arm 274. Installed inside of the bracket 275 is a printed circuit board 277 where an auxiliary lamp 276a, 276b and a drive circuit for supplying a driving power thereto are provided. The printed circuit board 277 is electrically connected with the electrode terminal 273 of the connection jack through an electric wire 278 embedded inside of the jack arm 274. The drive circuit in the printed circuit board 277 generates a driving power for the auxiliary lamp 276a, 276b, using an electric power transferred through the electrode terminal 273 and the electric wire 277. The auxiliary lamp- integrated connection jack 270 can be installed simply by inserting it into the hole formed in each lid plug 194-1, 194-2, which is installed in the lamp housing 190 of the lamp module 250-1, 250-2. In this way, the electrode terminal 273 of the connection jack 270 is coupled with an electrode terminal 194a, 194b provided in both lid plugs 194-1, 194-2, so that two lamp modules 250-1, 250-2 are connected to each other in parallel. At the same time, the auxiliary lamps 276a and 276b are automatically placed in front of the lamp holders 152-1, 152-2 between the two lamps 150, thereby eliminating discontinuity T of the emitting region. The lid plug 194-1, 194-2 may be provided with a depressed space formed so as to embed or receive the jack arm 274, such that the two lid plugs 194-1, 194-2 abut against each other not to create any gap between the two lamp modules 250- 1 and 250-2. This auxiliary lamp-integrated connection jack 270 provides an advantage of installing an auxiliary lamp conveniently, i.e., when the connection jack 270 is inserted, the auxiliary lamp comes to be automatically installed.

[86] Referring to Figs. 20 to 22 again, the frame 180 includes a hinged cover 185 for covering the accommodation space. The hinged cover 185 is provided with a leaf spring 187 mounted at the inner face thereof, such that it can be opened and closed from the front side, due to resiliency of the leaf spring 187. The cover 135, on which a sign member 110 is fixed, has the form of a flat plate having no opening and has a size enough to cover almost the entire front face of the sign board apparatus. The edge portion of the cover 135 is detachably attached to the frame 180, using a screw 214. In case where the cover 135 is formed of, for example, a transparent material such as acryl, an inner cover plate 120 providing a desired background color may be further attached to the light guide plate 140 side of the cover 135. Of course, the cover 135 may have an opening at its center such that the inner cover plate 120 can be exposed, except for its edge portions. In case where the cover 135 is made of an opaque material, it may be structured such that the portion corresponding to the light guide plate 140 is made open and the opened portion is covered by the inner cover plate 120. Stacked on the surface of the cover 135 or the inner cover plate 120 are various sign members 110 in various combinations, which express an ad-content by means of light- emission. In order for the light guide plate 140 to be secured inside the frame 180 without clearance, an auxiliary member 252-1, 252-2 having the same shape as the lamp housing 190 is disposed at lateral spaces of the frame 180 which is not occupied by the lamp module 250.

[87] The sign board apparatus 200-1 shown in Fig. 23 is a modification to that 200 of

Fig. 20. This sign board apparatus 200-1 differs from Fig. 22, in that the cover 135-1 has a size roughly to cover the light guide plate 140 and the hinged cover 185 of the frame 180 is exposed. The cover 135-1 is, at its edge portion, detachably attached to the edge of the hinged cover 185, using a screw 214. The construction of the sign member 110 may be varied, for example, further providing a fluorescent resin plate 119 to the outermost face thereof.

[88] Fig. 24 shows another variation of the sign board apparatus 200 of Fig. 22. The cover 130-1 is fabricated in the form of a cap ( -shaped), for example, made of an opaque material. The cover 130-1 is structured such that it covers the entire light guide plate 140 and frame 180, but the portion facing the light guide plate 140 is opened and the inner face of the opened portion is covered by an inner cover plate 120 formed of a transparent material. For instance, as illustrated, a screw 210 is fastened in the lateral side of the cover 130-1 so as to be latched at the bottom of the frame 180, thereby preventing the cover 130-1 from releasing from the frame 180. When necessary, the screw 210 can be unfastened to detach the cover 130-1 from the frame 180. Various combinations of sign members 110 are stacked on the inner cover plate 120.

[89] In the sign board apparatuses illustrated in Figs. 22 to 24, the lamp modules 250-1,

250-2, 250-3 and 250-4 have a water-proofing function of its own, but may be provided with a dual water-proofing means for ensuring a robust water-proofing. For this purpose, preferably a water-proof film 122 is further installed in a way to wrap around the lamp modules 250-1, 250-2, 250-3 and 250-4 including the lamp 150 and the lamp drive circuit 160, thereby preventing moisture from penetrating the inside thereof. In addition, as previously mentioned, attached to the cover 130-1, 135, 135-1 or the inner cover plate 120 is a sign member 110 formed by three-dimensionally stacking transparent and opaque materials in various combinations. These sign board apparatuses 200, 200-1 and 200-2 can be secured, for example, on a wall (not shown), using a fastener means 220. The fixing means 220 includes, for example, an L-shaped fixing plate 226, a fixing bolt 228, 229, and a bolt and a connection bar 224 for connecting the fixing plate 226 with the frame 180. Further, the frame 180 may be secured to a surrounding fixed structure (not shown) by means of a screw 212. When the sign board unit needs to be replaced, it can be detached from these sign board apparatuses 200, 200-1, and 200-2 by releasing the fastener means, i.e., the screws 210 and 214 tightened between the cover 130-1, 135 and 135-1 of the sign board unit and the backlight unit. In addition, in case where the lamp of the backlight unit does not come to turn on, the cover 130-1, 135, 135-1 can be detached (in case of Figs. 22 and 24), or the hinged cover 185 can be opened (in case of Fig. 23) and then only the lamp module 250 can be replaced with other one, thereby enabling to easily fixing defects relevant to the lamps and their lighting.

[90]

[91] (4) Fourth embodiment

[92] Fig. 27 is an exploded perspective view showing a sign board apparatus 300 according to the fourth embodiment of the invention. Typically, the sign board is constituted of an expression region being occupied by phrases, figures and symbols, and a background region for the expression region. In order for the sign board to effectively draw people's attention, it is thought to be better to provide a difference in the luminance between the two regions, i.e., to make either one of the expression region and the background region to be brighter than the other. This thought is adopted in the sign board apparatus 300 of fourth embodiment. In the sign board apparatus 300, the sign board unit 320 includes a plurality of sign members 324a, 324b and 324c for expressing desired contents. The sign members are combined to the cover 322. The cover 322 has an opening, to which the sign members 324a, 324b and 324c are attached by means of an adhesive or the like. The sign members 324a, 324b and 324c may not be attached directly to the cover 322. That is, the portion, where the sign members are to be placed, is machined to be opened. An inner cover plate (not shown) made of a transparent material is attached to the cover so as to cover the opened area. Then, the sign members 324a, 324b and 324c may be attached to the inner cover plate. The backlight unit 310 is constructed so as to conform to this arrangement of the sign board unit 320. Here, this backlight may be secured directly to a wall. Alternatively, the backlight is fixed to a support plate 312, which is then secured to a wall. That is, the backlight unit 310 is fixed to a wall structure (not shown) using for example a bolt 314. Of course, the sign board unit 320 is joined with the support plate 312 by means of a screw 326 or the like, so that it can be easily detached, when necessary. On the top face of the support plate 312, a backlight unit 310a, 310b, 310c is disposed at the areas facing each sign members 324a, 324b, 324c. That is, the backlight unit is disposed separately for each sign member. In connection with the arrangement of the backlight unit, the sign member and the backlight unit may be arranged in such a one-to-one fashion, but a single backlight unit may be installed for multiple sign members. For instance, in the case of a big sign board and multiple sign members to be arranged thereon, the areas, in which the sign members are to be arranged can be grouped, based on their spatial closeness and then each group can be provided with one light guide plate.

[93] Figs. 28 and 29 show modifications to the fourth embodiment. This sign board apparatus 400 is configured such that a certain specific expression region is illuminated brighter than others, i.e., using a backlight unit 420 capable of differential light e missions. That is, as shown in Fig. 28, the backlight unit 420 has a size corresponding to that of the sign board unit 410. However, a light scattering element 424 is formed in the light guide plate 422 of the backlight unit 420 so as to correspond to the areas 412 only where the sign members of the sign board unit 410 are provided. If Fig. 27 is the case, the light scattering element is formed only in the areas having the same shapes as the sign members 324a, 324b and 324c. The light scattering element 424 is formed, for example, a fine depression pattern made up of numerous fine depressions to the extent to be invisible with naked eyes, multiple dot ink pattern, and a V-cut pattern made up of multiple V-shape grooves. Example ways to form a depression pattern include a sandblasting process, an injection molding process, an extrusion forming process, and the like. It is preferable to further attach a light reflector film (not shown) to the bottom floor of the light guide plate 422.

[94] One or more lamp modules described in connection with Figs. 15 and 26 are disposed in at least one lateral side of the light guide plate 422. The frame 426 holds the light guide plate 422 and the lamp module 250 to maintain this arrangement. Light incident inside of the light guide plate 422 by the lamp 150 of the lamp module 250 is scattered and reflected by means of a light-scattering element 424 formed in the bottom floor of the light guide plate 422 and then externally output through the top face of the light guide plate 422. The portions in the bottom floor of the light guide plate 422, where the light-scattering element is not formed, causes the light to be total- internally reflected. The total-internally reflected light is mostly total-internally reflected again in the top face of the light guide plate 422, so that not so much light escapes the light guide plate. That is, since the lamp 150 generates a certain amount of light and the light- scattering element 424 area forms most of the light-output region, the light-scattering element area is made to be much brighter, as compared with the case where the light is uniformly output over the entire surface of the light guide plate. Thus, in the whole bottom area of the light guide plate 422, the light- scattering element 424 area comes to brighten brighter than the other remaining area. Preferably, the sign member 412 area facing the light-scattering element 424 area is formed of a material generating its unique color by the backlight, such as a fluorescent acrylic resin plate, a transparent acrylic resin plate, and the like. The materials for other areas are not particularly limited, but may include various materials including light-transmissible (transparent) materials and opaque materials. Since, in any case, the light- scattering element 424 is formed only in the portions where the light guide plate 422 faces the sign member 412 area, the light guide plate 422 becomes much more brighter in the light- scattering element 424 areas, rather than the other areas. Therefore, in the sign board unit 410, the sign member 412 area facing the light-scattering element 424 area is expressed and exhibited more brightly. Further, the sign board unit 410 is combined with the backlight unit 420, for example, using a screw 414 so as to be detached from each other, when necessary.

[95]

[96] (5) Fifth embodiment

[97] Figs. 30 and 31 show a sign board apparatus 500 according to the fifth embodiment of the invention. The sign board apparatus is structured in a way that an advertisement film 530 is further provided to the sign board apparatus 200 (Figs. 20 to 22) of third embodiment. That is, in the sign board apparatus 500 of this embodiment, a cover 520 is disposed on the light guide plate 140 of the backlight unit 260 and a 3-dimensional sign member 510 is combined on the top face of the cover 520, which serves as a base plate for the sign member. On top thereof, the advertisement film 530 ("ad-film") is placed. Then the film 530 and the cover 520 are covered by a hinged cover 185 of the frame so as to be secured and held in place by means of the hinged cover 185. For more reliable installation, a screw 214 may be used to fasten the hinged cover 185, the film 530 and the cover 520 to each other.

[98] In order for the ad-film 530 to be brightly expressed by the backlight, it is preferable that the cover 520 is formed of a transparent material. As illustrated, in order for the 3-dimensional sign member 510 not to be veiled by the ad- film 530, preferably the portion of the ad- film 530 corresponding to the sign member 510 is cut to form an opening 534 and the remaining portion thereof may be printed with an ad- content 532 such as figures, letters, photos and the like. Such an ad-film 530 is placed on the transparent cover 520 and then the 3-dimensional sign member 510 is brightly exposed, with having the brightening ad-content 532 on the ad-film as a background. Dissimilar to this arrangement, the ad-film 530 may be disposed under the cover 520, i.e., between the backlight unit 260 and the cover 520. In this case, the ad-film 530 does not need to be cut out, with respect to the portions facing the 3-dimensioanl sign member 510.

[99] As described above, this sign board apparatus 500 further includes a printable ad- film 530, along with the 3-D sign member 510, in order to express an ad-content. In some cases, the 3-D sign member 510 alone may have a difficulty in expressing a sophisticate ad-content, or a photo, picture and the like. In the fifth embodiment, such ad- contents can be expressed using the ad-film 530, thereby harmonizing the unique advantages of the 3-D sign member and the ad-film. As the result, a variety of expressions can be achieved, in terms of designing the ad-contents of a sign board.

[100] The concept of this embodiment, i.e., combination of a sign member and a film, can be applied to each of the previous embodiment. Further, besides the film, a thin element may be further provided as an expressing means. By way of example, a partial selective emission type backlight unit 420 can be adopted in the fifth embodiment. That is, instead of the light guide plate 140 of Fig. 30 providing a uniform- luminance background light over the entire top face thereof, an alternative light guide plate can be adopted, which is designed such that its light-scattering element is formed only in the ad-content 532 portion of the film 530 and the portion facing the 3-D sign member 510 in order to provide a brighter background light to these portions, rather than the remaining portions. If such a light guide plate is employed in the backlight unit, the ad- content 532 portion of the film 530 and the 3-D sign member 510 portion are made brighter than the remaining background area and thus empathetically expressed.

[101] (6) Other variations to the embodiments

[102] The lamp used in the previous embodiments has a thickness, preferably, no larger than that of the light guide plate. Otherwise, a light loss may increase. Preferred examples for the lamp include a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL) and the like. These lamps can be used each individually or in combinations of two or more to construct a lamp unit. In case of LEDs, a lamp unit can be configured such that a lamp unit can be configured such that a plurality of LEDs is arranged in one or two rows along the lateral side of the light guide plate as much as the length thereof. In case where the LEDs are capable of emitting lights of three primary colors and have a good controlled blinking capability, a further diversification to the expressions can be achieved.

[103] The fastener means 220 mentioned in the third embodiment can be applied to other embodiments or can be slightly modified for applying to other embodiments. Sign boards are installed usually outdoor and thus requires a water-proofing. Each embodiment has mentioned a water-proofing structure. Additionally, in order to reinforce the water-proofing function, there may be further provided a transparent water-proof member covering at least part of the light guide plate and the light source unit to thereby preventing moisture from penetrating into the inside of the light source unit.

[104] Although the present invention has been described with reference to several preferred embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. For example, the lamp is illustrated as being a cold cathode fluorescent lamp in the drawings, but of course an LED lamp can be adopted. Various modifications and variations to the embodiments, including equivalents thereof, may readily occur to those skilled in the art from the above description, without departing from the spirit and scope of the invention, as defined by the appended claims. Industrial Applicability

[105] The sign board apparatus of the invention allows the ad-contents thereof to be flexibly replaced or changed, with minimum cost and labor. That is, only the sign board unit can be replaced with a new one, with the backlight unit remained in place. Thus, replacement of a new sign board can be carried out in a very simple way, relatively to the conventional techniques. When necessary, the sign board can be partially replaced or modified.

[106] In addition, the sign board apparatus of the invention can be commercialized as ready-made products or ready-to-assemble sign boards or assembling kits. Using them, a user can assemble to construct a sign board, using them. For instance, each English alphabet can be made into a standardized sign board apparatus and thus the user can assemble the letters of standardized apparatus to construct a sign board apparatus expressing a desired phase.

Claims

[1] A sign board apparatus comprising: a backlight unit including a light guide plate having a light- scattering element provided in a bottom floor thereof and a light source having a lamp disposed in at least one lateral side of the light guide plate, the light of the lamp being provided inside of the light guide plate through the lateral side thereof, the light of the lamp incident through the lateral side of the light guide plate being scattered and reflected by the light- scattering element and emitted towards a top face of the light guide plate; and a sign board unit including a cover detachably combined with the backlight unit and covering the top face of the backlight unit, at least part of the cover area being opened or made of a transparent plate so as to pass the light provided by the backlight unit, and a 3-dimensional sign member inserted into the opening of the cover or attached to the transparent plate thereof, the sign member being made of a light-transmissible material passing light and generating a unique color, or an opaque material shielding light-transmission, or both of the transparent material and the opaque material, wherein the 3-dimesional sign member exhibits an inherent color thereof in a 3-dimensional way by means of the backlight, and if necessary, only the sign board unit can be removed from the backlight unit and replaced with a new one, with the backlight unit remained in place.

[2] The apparatus as claimed in claim 1, wherein the backlight unit further includes a frame integrating the light guide plate and the light source into a single body.

[3] The apparatus as claimed in claim 1, wherein the cover serves as a frame holding the light guide plate and the light source into a single body and simultaneously covering at least part of the top face of the backlight unit.

[4] The apparatus as claimed in claim 1, wherein the light- transmissible material of the sign member includes a light-transmissible material and a semi-transmissible material such as transparent or translucent acrylic resin plates, fluorescent acrylic plates, light-transmissible color films and the like.

[5] The apparatus as claimed in claim 1, wherein the 3-dimemsional sign member has a layered structure formed of multiple sign members having identical sizes or different sizes.

[6] The apparatus as claimed in claim 1, wherein the backlight unit has a slim structure having a thickness of no more than 30 mm.

[7] The apparatus as claimed in claim 1, wherein the 3-dimensional sign member, inserted into the opening, is fixed using an adhesive so as not to create a gap in- between with an edge of the opening.

[8] The apparatus as claimed in claim 1, wherein the light source includes at least one lamp module, the lamp module including a lamp unit having at least one lamp disposed along the lateral side of the light guide plate, the lamp emitting light when a driving power is supplied; a lamp drive circuit providing the driving power to the lamp; and a lamp housing having a light reflector trough and a tube member integrated with each other, the lamp housing having a first electrode terminal electrically connected with the lamp drive circuit and disposed in a certain position so as to be electrically connected from outside, the lamp drive circuit and the lamp being received in and integrally combined with the tube member and the light reflector trough respectively with an output terminal of the lamp drive circuit connected to an electrode of the lamp.

[9] The apparatus claimed in claim 8, wherein the lamp housing further includes a second electrode terminal connected electrically in parallel with the first electrode terminal and exposed so as to enable to be externally connected, the first and second electrode terminals being disposed at both lengthwise ends of the lamp housing.

[10] The apparatus as claimed in claim 9, wherein the light source includes a multiple number of the lamp modules of which total length is substantially equal to the whole length of light- incident lateral side of the light guide plate, and at least one connection jack electrically connecting the multiple lamp modules, wherein the multiple lamp modules are linearly arranged in a row along the light- incident lateral side, and the connection jack is interposed between two adjacent lamp modules such that the first electrode terminal of the one of the two adjacent lamp modules is connected in parallel to the second electrode terminal of the other one of the two adjacent lamp modules.

[11] The apparatus as claimed in claim 9, wherein the lamp is a straight- tube type lamp, and the lamp module further includes a lamp holder gripping and fixing both ends of the straight-tube type lamp to the lamp housing; and an auxiliary lamp installed in a non-emission area at both end portions of the straight-tube type lamp where the lamp is not exposed, wherein the straight-tube type lamp and the auxiliary lamp emit light together by an electric power supplied from the lamp drive circuit, thereby allowing the entire length of the lamp module to emit light.

[12] The apparatus as claimed in claim 11, wherein the light source further includes one or more connection jacks electrically connecting a plurality of lamp modules, and wherein the plurality of the lamp modules are linearly arranged in a row along the light-incident lateral side, and the connection jack is interposed between two adjacent lamp modules such that the first electrode terminal of the one of the two adjacent lamp modules is connected in parallel to the second electrode terminal of the other one of the two adjacent lamp modules.

[13] The apparatus as claimed in claim 9, wherein the lamp is a straight- tube type lamp, and the lamp module further includes a lamp holder gripping and fixing both ends of the straight-tube type lamp to the lamp housing, and wherein the light source further includes an auxiliary lamp-integrated connection jack, the auxiliary lamp-integrated connection jack further includes one or more connection jack electrically connecting multiple lamp modules; an auxiliary lamp integrated with the connection jack, the auxiliary lamp being automatically disposed between two adjacent lamp modules when connected by the connection jack, so that the straight-tube type lamp and the auxiliary lamp emit light together, without discontinuity between two adjacent lamp modules.

[14] The apparatus as claimed in claim 12 or 13, wherein, in case where the auxiliary lamp protrudes towards the light-incident side of the light guide plate further than the straight-tube type lamp, the light guide plate is provided with a receiving space formed in a lateral side facing the auxiliary lamp so as to accommodate the protruded portion of the auxiliary lamp.

[15] The apparatus as claimed in claim 8, wherein the backlight unit further includes a frame designed to receive and grip the light guide plate and the lamp module so as to be held close to a lateral side of the light guide plate, and, when necessary, to enable to release and replace the lamp module.

[16] The apparatus as claimed in claim 1, wherein the lamp includes a multiple number of lamps arranged in a row along a lateral side of the light guide plate, and each lamp is selected from the group consisting of a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL) and an external electrode fluorescent lamp (EEFL).

[17] The apparatus as claimed in claim 1, further comprising a transparent waterproof member covering at least part of the light guide plate and the light source to prevent moisture from penetrating into inside of the light source.

[18] The apparatus as claimed in any one of claims 1 to 17, wherein the light- scattering element is disposed, among the entire bottom floor of the light guide plate, only in portions corresponding to the opening of the cover or the transparent base plate, such that light is intensively emitted from the light- scattering element region.

[19] The apparatus as claimed in any one of claims 1 to 17, wherein, in case where the opening areas and the transparent base plate areas are distributed over multiple locations, the backlight unit is disposed for each opening area and transparent base plate, or the opening area and the transparent base plate areas are grouped based on spatial closeness thereof and each group is provided with the backlight unit.

[20] The apparatus as claimed in any one of claims 1 to 17, further comprising an advertisement film disposed and fixed between the sign board unit and the backlight unit, or on top face of the sign board unit so as not to veil the 3-dimensional sign member, the advertisement film being printed with a content to be expressed.

[21] The apparatus as claimed in claim 1, wherein the cover includes a cup-shaped cover detachably combined with the backlight unit so as to cover a lateral side and part of an edge area of top face of the backlight unit and be open at a portion facing the light guide plate to be light-transmissible; and a water-proof plate covering the opened area of the cup-shaped cover and of which overlapped portions are adhered to each other to prevent moisture from penetrating from outside, the water-proof plate being made of a transparent plate material to allow light-transmission.

[22] A backlight apparatus capable of differential light-emission, comprising: a light guide plate having a light- scattering element provided only in a certain portion of the bottom floor thereof; a light source including one or more lamp and a power supply for lighting the lamp, the light generated by the lamp being incident through at least one lateral side of the light guide plate; and a frame for gripping and supporting the light guide plate and the light source so as for the light source to be held close to a lateral side of the light guide plate, wherein light introduced through the lateral side of the light guide plate is scattered mainly in the certain portion such that, among the entire top face of the light guide plate, a portion facing the certain portion is brightened more brightly than the other remaining portion thereof.

[23] The apparatus as claimed in claim 22, wherein the light guide plate is made of a transparent acrylic resin plate material and the light-scattering element is formed of numerous fine depressions formed only in the certain portion to extent to be invisible with naked eyes.

[24] The apparatus as claimed in claim 23, wherein a light reflector film is further attached to the bottom floor of the light guide plate, thereby allowing the backlight apparatus to be applied to a sign board apparatus.