201015602 九、發明說明： .【發明所屬之技術領域】 本發明涉及一種背光鍵盤，尤其涉及一種厚度較薄之 背光鍵盤。 / 【先前技術】 背光鍵盤可依靠其内部發光元件產生之光線照亮鍵 ❹ 盤，使用者在光線不足之情況下也可容易地辨識背光^盤 中各按鍵之位置，從而方便使用。目前，背光鍵盤廣泛應 用於手機、筆記型電腦、個人電腦、音樂播放器等便攜= 電子設備中。 "" 一種應用於手機之背光鍵盤，其包括按鍵、依次設置 於按鍵下方之遮光膜、導光板、彈片和光源。按鍵包ς鍵 體以及罩設於鍵體頂部並與其相黏接之鍵帽，鍵帽上通常 設有可透光之文字或符號。使用時，按壓按鍵，鍵體抵頂 彈片並使彈片發生彈性變形，彈片上設置之觸點使手機電 ©路板上之電路導通。遮光膜通常為一黑色塑膠薄膜，其用 於正向遮光，以使光源發出之光線經導光板勻光後，僅能 從遮光膜之開孔處出射並照亮鍵帽上之文字或符號。 一然，上述背光鍵盤中，按鍵與遮光膜分別單獨成型， 几件數量較多，增加了製造成本，也不便於装配。同時， 按鍵需具有較大之厚度以滿足製造和使用之要求， 光鍵盤厚度較大，不利於手機等便攜式電子裝置之薄型化 5¾ 言4* 〇 7 201015602 【發明内容】 蓥於上述内有必要提供—種厚度較薄之背光鍵盤。 -種背光鍵盤，其包括複數按鍵、導光板、遮光片、 彈片及《又置於導光板上之光源。每―按鍵包括鍵頂及與鍵 頂相連之抵>14，彈片包括與按鍵之抵壓部相對應之受壓 部。導光板鄰近按鍵i形成有出光部，遮光片設置於出 ❹ 光部所在-侧’出光部上除需要光線出射之部位外由遮光 片遮蔽。遮光片為金屬件，且遮光片與按鍵藉由欲入成型 技術結合為一體。 上述背光鍵盤，採用金屬件作為遮光片實現遮光，且 遮光片與按鍵藉由嵌入成型技術結合為一體，遮光片厚度 以及與之相結合之按鍵之厚度均可較薄，從而滿足背光鍵 盤之薄型化設計要求，此外，還簡化了結構，便於製造和 裝配。 ®【實施方式】 本發明背光鍵盤可應用於手機等便攜式電子裝置中。 下面結合附圖及實施例對本發明之背光鍵盤作進一步之詳 細說明^ 圖1所示為本發明實施例一之背光鍵盤，該背光鍵盤 100包括鍵帽110、按鍵120、遮光片130、導光板140以 及彈片160。鍵帽110與按鍵120相結合並設置於導光板 140上方，遮光片130設置於導光板14〇上並與按鍵12〇 201015602 * .藉由嵌入成型方式結合為一體，彈片160設置於導光板140 .下部。 每一按鍵120包括鍵頂121、連接部123及抵壓部125。 鍵頂121與連接部123及抵壓部125均採用透光性橡膠材 料製成。鍵頂121呈圓柱狀，連接部123由鍵頂121之外 圓週面沿徑向向外延伸形成，並與鍵頂121 —體成型。抵 壓部125形成於鍵頂121之底部，並可隨鍵頂121 —起動 作。 © 鍵帽110大致為一罩體，其可採用橡膠-樹脂黏結技術 罩設於鍵頂121頂部，鍵帽110上形成有可透光之文字或 圖案（圖未示），以便操作者識別對應之按鍵。鍵帽110可 呈整體結構覆蓋於各鍵頂121上，也可為單獨之結構，每 一鍵帽110對應覆蓋於一鍵頂121上。 遮光片130為不透光之金屬片，其可由延展性高之金 屬材料經塑性加工方法製成，其塑性加工方法可為鑄造、 衝壓、鍛造、衝鍛復合或壓鑄等。遮光片130上開設有複 ®數透光孔（圖未標），透光孔位置與鍵帽110以及其他需要 光線出射之部位相對應。遮光片130之材料可為鋼板、鋁 板、不銹鋼板或鋁合金板，其上之透光孔可藉由衝壓成型。 遮光片130與各按鍵120藉由嵌入成型技術（Insert Molding)成型為一體，成型後，遮光片130上與鍵帽110 相對應之透光孔之週緣部嵌入按鍵120之連接部123中。 上述將遮光片130與按鍵120藉由嵌入成型結合為一 體之方法大致包括以下步驟：（1 )將金屬材料經塑性加工 9 201015602 方法製成金屬片，其塑性加I方法可為鑄造、衝壓、鍛 復合或料；⑺對金屬片進行加工形成複數與 百 相對之通孔，通孔也可於步驟（1)中盥金屬片一 起成型：⑺將金屬片喪入一成型模具中，該成、型模具具 有與按鍵12G相對應之模腔形狀；（4)向·模呈之模腔 内注入成型材料，該成型材料為透光性橡膠材料，冷卻後 形成按鍵120與遮光片130之結合件。 為使按鍵120與遮光片130結合更為牢靠，進一步還 ❿可於遮光片130上透光孔之邊緣部形成弯折扣合結構（圖 未示）’或者於遮光片130上鄰近透光孔之位置開設一個或 者複數直徑較小之結合孔或設置凸包，嵌入成型時，成型 材料可包圍扣合結構或注入結合孔、凸包，成型後使按鍵 120與遮光片130結合處形成相互扣接之結構。 導光板140由可透光之材料製成’如聚碳酸醋（pc)、 聚甲基丙烯酸曱脂（PMMA)、聚苯乙烯（ps)、苯乙烯甲 ❿基丙烯酸甲酯等。導光板140具有一出光面143、與出光面 143相對之底面145以及侧壁147 ’出光面143與底面145 間具有一定厚度。導光板140上沿其厚度方向開設有貫穿 出光面143及底面145之通孔142,通孔142之位置與設置 於導光板140上之鍵頂121之位置相對應。導光板14〇之 出光面143侧形成有出光部141，該出光部ι41由出光面 143以及通孔142構成。導光板140 —側壁147上設置有複 數平行排佈之光源148 ’如發光二極體點光源，用於照亮導 光板140。光源148發出之光線於導光板142中擴散和勻光 201015602 .後主要從出光部141出射。 - 彈片160設置於導光板140之下方，其包括基部161 -及複數受壓部162,受壓部162朝導光板140方向凸神旅形 成半圓環形，其伸入導光板140之通孔142内，並可於外 力作用下產生彈性變形。每一受壓部162之内表面上設置 有觸點164,觸點164用於使電子裝置電路板上之電路電十生 連接。 裝配時，將按鍵120以及遮光片130之結合體設置於 ©導光板140上方，遮光片130蓋設於導光板140上放與導 光板140出光面143相接觸。按鍵120之鍵頂121之抵® 部125正對導光板140之通孔142,且抵壓部125伸入通孔 142中。將彈片160設置於導光板140下部，彈片160之基 部161與導光板140之底面145相接觸，彈片160之每一 受壓部162正對導光板140之通孔142並伸入其中，使彈 片160之受壓部162與按鍵12〇之鍵頂121之抵壓部125 相對應。 使用時’當施加壓力至按鍵120之鍵帽110上時，鍵 頂121向下移動，鍵頂121之抵壓部125則抵壓彈片160 之受壓部162使其產生彈性變形，使觸點164將電路板上 之電路導通，當撤銷按壓力後，鍵頂於連接部123之 作用下恢復至原來之位置，彈片16〇之受壓部162也恢復 至原形，從而元成對按鍵120之按壓過程。 在光線不足之情沉下使用該背光鍵盤1〇〇時，設置於 導光板140 —側之複數點光源ι48發出之光線於導光板ι4〇 11 201015602 .中進行擴散和勻光，其可照亮導光板140。因導光板140 -之出光部141上蓋設有遮光片130,並藉由遮蔽片130遮蔽 .除需要光線出射之外的部位，因此從光源148發出之光線 不會從導光板140之出光部141被遮蔽之部位出射，而僅 照亮背光鍵盤100之鍵頂121以及鍵帽110上之文字和圖 案。由於光線得到有效利用，使較多之光線用以照亮鍵帽 110，即使在光線不足之環境下，操作者也可很容易辨識出 背光鍵盤100各按鍵120之位置，從而便於使用和操作該 ❿背光鍵盤100上之按鍵120。 實施例一中，背光鍵盤100之遮光片130為不透光之 金屬片，從而導光板140之出光部141上無需光線出射之 區域可藉由遮光片130完全遮蔽，使需要光照之地方得到 良好之光照。在需要光線出射之地方，可經過衝壓等簡單 工藝於遮光片130上形成相應之出光孔。同時，因遮光片 130為金屬片，其具有光亮之表面，不僅可起到遮光作用還 能夠反射光線，使得光線經數次反射後從出光部141射出， w從而可提高光線之利用率。此外，遮光片130與按鍵120 藉由嵌入成型技術結合為一體，簡化了結構，減少生產工 序以及製造和裝配之工時。因遮光片130厚度可以較薄， 與之結合之按鍵120之連接部123以及鍵頂121之厚度可 減小，從而可縮減按鍵120之厚度以滿足薄型化設計之要 求。 此外，本發明之背光鍵盤100中之導光板140上形成 有通孔142，按鍵120之抵壓部125伸入通孔142中，相應 12 201015602 .設置於導光板140下部之彈片160之受壓部162也伸入於 ,導光板142之通孔中，從而無需為鍵頂121以及受壓部162 .預留空間，從而進一步縮減了整個背光鍵盤100之厚度。 可以理解，本發明背光鍵盤100之遮光片130其週邊 也可向一侧垂直延伸出侧壁（圖未示），該延伸出之侧壁用 於包圍導光板140之週向側壁147，從而從侧面遮蔽光線， 提高遮光效果，也使得光線於導光板140内形成全反射， 進一步提高光線之利用率。 ❿ 圖2所示為本發明實施例二之背光鍵盤，該背光鍵盤 200包括導光板240、設置於導光板240 —侧之光源243以 及依次設置於導光板240上方之薄膜電路板280、彈片 260、遮光片230、按鍵220以及鍵帽210，彈片260與薄 膜電路板280間還設有起支撐作用之架板290。其中，彈片 260、架板290以及薄膜電路板280均由可透光材料製成。 按鍵220與遮光片230藉由實施例一中所述之嵌入成型方 法結合為一體。本實施例中，為便於按鍵220與遮光片230 ®之結合體設置於彈片260上方，遮光片230上之開孔處彎 折形成凸出之嵌入部231，嵌入部231嵌入按鍵220。彈片 260為平板形，其包括與按鍵220相對應之受壓部261，受 壓部261底部設有觸點2613，觸點2613伸入架板290上之 穿孔中。使用時，按壓鍵帽210，按鍵220向下運動抵頂彈 片260之受壓部2613,使彈片260發生彈性形變，觸點2613 將薄膜電路板280上之電路導通。導光板240之上表面構 成出光部241。光源243發出之光線進入導光板240進行擴 13 201015602 .散和勻光後，從出光部241出射。光線依次穿過可透光之 -薄膜電路板280、架板290以及彈片260後，在不需要出光 .之部位，由遮光片230遮擋，從而光線僅能照亮按鍵220 及鍵帽210上之文字和圖案區，從而有效利用光線。 實施例二中，因按鍵220與遮光片230藉由嵌入成型 技術結合為一體，金屬遮光片230以及與之相結合之按鍵 220之厚度均可較薄，從而可縮減背光鍵盤200之整體厚 度，滿足薄型化設計之要求。 〇 綜上所述，本發明確已符合發明專利之要件，遂依法 提出專利申請。惟，以上所述者僅為本發明之較佳實施方 式，自不能以此限制本案之申請專利範圍。舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化，皆 應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1係本發明實施例一背光鍵盤之示意圖。 圖2係本發明實施例二背光鍵盤之示意圖。 ®【主要元件符號說明】 背光鍵盤 100 ' 200 鍵帽 110 、 210 按鍵 120、220 鍵頂 121 連接部 123 抵壓部 125 遮光片 130、230 導光板 140 、 240 出光部 141 、 241 通孔 142 出光面 143 底面 145 侧壁 147 光源 148 、 243 14 201015602 . 彈片 160 、 260 基部 161 . 受壓部 162 ' 261 觸點 164 、 2613 . 嵌入部 231 薄膜電路板 280 架板 290201015602 IX. INSTRUCTIONS: [Technical Field] The present invention relates to a backlit keyboard, and more particularly to a backlit keyboard having a relatively thin thickness. / [Prior Art] The backlit keyboard can illuminate the key disk by the light generated by its internal light-emitting elements. The user can easily recognize the position of each button in the backlight when the light is insufficient, so that it is convenient to use. Currently, backlit keyboards are widely used in portable=electronic devices such as mobile phones, notebook computers, personal computers, and music players. "" A backlit keyboard for mobile phones that includes buttons, a light-shielding film, a light guide plate, a shrapnel, and a light source that are sequentially disposed under the keys. The button includes a button body and a key cap that is disposed on the top of the key body and is bonded thereto. The key cap is usually provided with a light-transmissive text or symbol. When in use, press the button, the key body abuts the elastic piece and elastically deforms the elastic piece, and the contact provided on the elastic piece makes the circuit of the mobile phone electric circuit board conduct. The light-shielding film is usually a black plastic film, which is used for positive light-shielding, so that the light emitted by the light source can be lighted through the light guide plate and can only be emitted from the opening of the light-shielding film and illuminate the characters or symbols on the keycap. In the above backlight keyboard, the button and the light shielding film are separately formed separately, and the number of the parts is large, which increases the manufacturing cost and is not easy to assemble. At the same time, the button needs to have a large thickness to meet the requirements of manufacturing and use, and the thickness of the optical keyboard is large, which is not conducive to the thinning of portable electronic devices such as mobile phones. 53⁄4 言 4* 〇7 201015602 [Summary of the invention] Provides a thin backlit keyboard. A backlit keyboard comprising a plurality of buttons, a light guide plate, a light shield, a shrapnel, and a light source that is placed on the light guide plate. Each of the "keys" includes a key top and a contact with the top of the key. The spring piece includes a pressure receiving portion corresponding to the pressing portion of the key. The light guide plate is formed with a light exiting portion adjacent to the button i, and the light shielding sheet is disposed on the light exiting portion where the light exiting portion is located on the side of the light exiting portion, and is shielded by the light shielding sheet except for the portion where the light is required to be emitted. The visor is a metal piece, and the visor and the button are integrated by the molding technique. The backlight keyboard adopts a metal member as a light shielding film to realize light shielding, and the light shielding film and the button are integrated by insert molding technology, and the thickness of the light shielding film and the thickness of the combined button can be thin, thereby satisfying the thin shape of the backlight keyboard. Design requirements, in addition, simplify the structure and facilitate manufacturing and assembly. ® [Embodiment] The backlight keyboard of the present invention can be applied to a portable electronic device such as a mobile phone. The backlight keyboard of the present invention is further described in detail with reference to the accompanying drawings and embodiments. FIG. 1 is a backlight keyboard according to a first embodiment of the present invention. The backlight keyboard 100 includes a key cap 110, a button 120, a light shielding film 130, and a light guide plate. 140 and shrapnel 160. The key cap 110 is disposed on the light guide plate 140 and is disposed on the light guide plate 140. The light shielding plate 130 is disposed on the light guide plate 14A and integrated with the button 12〇201015602*. The elastic piece 160 is disposed on the light guide plate 140. . Lower part. Each of the keys 120 includes a key top 121, a connecting portion 123, and a pressing portion 125. The key top 121, the connecting portion 123, and the pressing portion 125 are made of a light transmissive rubber material. The key top 121 has a cylindrical shape, and the connecting portion 123 is formed to extend radially outward from the outer circumferential surface of the key top 121, and is integrally formed with the key top 121. The pressing portion 125 is formed at the bottom of the key top 121 and can be activated with the key top 121. The key cap 110 is substantially a cover body, which can be covered on the top of the key top 121 by a rubber-resin bonding technique. The key cap 110 is formed with a light transmissive text or pattern (not shown) for the operator to recognize the corresponding The button. The key cap 110 can be covered on the key tops 121 as a whole structure, or can be a separate structure, and each of the key caps 110 correspondingly covers a key top 121. The light shielding sheet 130 is an opaque metal sheet which can be made by a plastic processing method from a metal material having high ductility, and the plastic working method can be casting, stamping, forging, punching forging or die casting. The light-shielding sheet 130 is provided with a plurality of light-transparent holes (not shown), and the position of the light-transmitting holes corresponds to the key cap 110 and other parts where light is required to be emitted. The material of the light shielding sheet 130 may be a steel plate, an aluminum plate, a stainless steel plate or an aluminum alloy plate, and the light transmission holes thereon may be formed by press forming. The light-shielding sheet 130 and each of the buttons 120 are integrally molded by insert molding. After molding, the peripheral portion of the light-transmitting hole corresponding to the key cap 110 of the light-shielding sheet 130 is embedded in the connecting portion 123 of the button 120. The method for integrating the light shielding sheet 130 and the button 120 by insert molding generally comprises the following steps: (1) forming a metal sheet by plastic processing by a plastic processing method of 9 201015602, and the plastic addition method can be casting, stamping, Forging composite or material; (7) processing the metal sheet to form a plurality of through holes corresponding to the hundred, the through hole may also be formed together with the metal sheet in the step (1): (7) the metal piece is immersed in a molding die, the The mold has a cavity shape corresponding to the button 12G; (4) a molding material is injected into the cavity formed by the mold, and the molding material is a translucent rubber material, and after cooling, a joint of the button 120 and the light shielding film 130 is formed. . In order to make the button 120 and the light shielding sheet 130 more securely combined, a bending discount structure (not shown) may be formed on the edge portion of the light transmission hole on the light shielding sheet 130 or adjacent to the light transmission hole on the light shielding sheet 130. The position is provided with one or a plurality of small diameter joint holes or a convex hull. When insert molding, the molding material can surround the fastening structure or the injection bonding hole and the convex hull. After the molding, the button 120 and the visor 130 are combined to form a mutual fastening. The structure. The light guide plate 140 is made of a light transmissive material such as polycarbonate (pc), polymethyl methacrylate (PMMA), polystyrene (ps), styrene methyl methacrylate or the like. The light guide plate 140 has a light-emitting surface 143, a bottom surface 145 opposite to the light-emitting surface 143, and a sidewall 147' having a thickness between the light-emitting surface 143 and the bottom surface 145. A through hole 142 is formed in the thickness direction of the light guide plate 140 through the light exit surface 143 and the bottom surface 145. The position of the through hole 142 corresponds to the position of the key top 121 disposed on the light guide plate 140. A light exiting portion 141 is formed on the light-emitting surface 143 side of the light guide plate 14A, and the light-emitting portion 141 is formed by the light-emitting surface 143 and the through hole 142. The light guide plate 140 - the side wall 147 is provided with a plurality of parallel arranged light sources 148 ' such as light emitting diode point light sources for illuminating the light guide plate 140. The light emitted by the light source 148 is diffused and condensed in the light guide plate 142. The light is emitted from the light exit portion 141. The elastic piece 160 is disposed under the light guide plate 140 and includes a base portion 161 - and a plurality of pressure receiving portions 162. The pressure receiving portion 162 protrudes toward the light guide plate 140 to form a semicircular ring shape, and extends into the through hole 142 of the light guide plate 140. And can produce elastic deformation under the action of external force. The inner surface of each of the pressure receiving portions 162 is provided with a contact 164 for electrically connecting the circuits on the electronic device circuit board. During assembly, the combination of the button 120 and the visor 130 is disposed above the light guide plate 140. The visor 130 is disposed on the light guide plate 140 and is in contact with the light exit surface 143 of the light guide plate 140. The abutting portion 125 of the key top 121 of the button 120 faces the through hole 142 of the light guide plate 140, and the pressing portion 125 projects into the through hole 142. The elastic piece 160 is disposed on the lower portion of the light guide plate 140, and the base portion 161 of the elastic piece 160 is in contact with the bottom surface 145 of the light guide plate 140. Each pressure receiving portion 162 of the elastic piece 160 faces the through hole 142 of the light guide plate 140 and protrudes therein to make the elastic piece The pressure receiving portion 162 of the 160 corresponds to the pressing portion 125 of the key top 121 of the button 12A. When in use, when the pressure is applied to the keycap 110 of the button 120, the key top 121 moves downward, and the pressing portion 125 of the key top 121 presses the pressed portion 162 of the elastic piece 160 to elastically deform the contact portion. 164, the circuit on the circuit board is turned on, when the pressing force is removed, the key is restored to the original position by the connection portion 123, and the pressed portion 162 of the elastic piece 16 恢复 is restored to the original shape, thereby the pair of the button 120 Press the process. When the backlight keyboard is used under the condition of insufficient light, the light emitted from the plurality of point light sources ι48 disposed on the side of the light guide plate 140 is diffused and homogenized in the light guide plate ι4〇11 201015602, which can illuminate Light guide plate 140. The light-emitting portion 141 of the light guide plate 140 is covered with a light-shielding sheet 130, and is shielded by the shielding sheet 130. The light emitted from the light source 148 does not pass from the light-emitting portion 141 of the light guide plate 140 except for the portion where the light is required to be emitted. The shaded portion is emitted, and only the key top 121 of the backlit keyboard 100 and the characters and patterns on the keycap 110 are illuminated. Since the light is effectively utilized, more light is used to illuminate the keycap 110, and even in a low-light environment, the operator can easily recognize the position of each button 120 of the backlit keyboard 100, thereby facilitating use and operation. The button 120 on the backlit keyboard 100. In the first embodiment, the light-shielding sheet 130 of the backlight keyboard 100 is an opaque metal sheet, so that the area of the light-emitting portion 141 of the light guide plate 140 that does not need light to be emitted can be completely shielded by the light-shielding sheet 130, so that the place where the light is needed is obtained well. The light. Where light is required to exit, a corresponding light exit hole may be formed on the light shielding sheet 130 by a simple process such as stamping. At the same time, since the light-shielding sheet 130 is a metal sheet, it has a bright surface, which not only functions as a light-shielding effect but also reflects light, so that the light is reflected from the light-emitting portion 141 after being reflected several times, thereby improving the utilization of light. In addition, the visor 130 and the button 120 are integrated by the insert molding technique, which simplifies the structure, reduces the number of production steps, and the man-hours for manufacturing and assembly. Since the thickness of the light shielding sheet 130 can be thin, the thickness of the connecting portion 123 and the key top 121 of the button 120 combined therewith can be reduced, so that the thickness of the key 120 can be reduced to meet the requirements of the thin design. In addition, the light guide plate 140 of the backlight keyboard 100 of the present invention is formed with a through hole 142, and the pressing portion 125 of the button 120 extends into the through hole 142, and the corresponding spring 12 is disposed on the lower portion of the light guide plate 140. The portion 162 also extends into the through hole of the light guide plate 142, so that there is no need to reserve space for the key top 121 and the pressure receiving portion 162, thereby further reducing the thickness of the entire backlit keyboard 100. It can be understood that the light shielding sheet 130 of the backlight keyboard 100 of the present invention may also have a side wall (not shown) extending perpendicularly to one side, and the extending side wall is for surrounding the circumferential side wall 147 of the light guide plate 140, thereby The side shields the light to improve the shading effect, and also causes the light to form a total reflection in the light guide plate 140, thereby further improving the utilization of the light. 2 is a backlight keyboard according to a second embodiment of the present invention. The backlight keyboard 200 includes a light guide plate 240, a light source 243 disposed on the side of the light guide plate 240, and a thin film circuit board 280 and a spring piece 260 disposed above the light guide plate 240. The visor 230, the button 220, and the keycap 210 are further provided with a support plate 290 between the elastic piece 260 and the film circuit board 280. The elastic piece 260, the shelf plate 290, and the thin film circuit board 280 are all made of a light transmissive material. The button 220 and the light shielding sheet 230 are integrated by the insert molding method described in the first embodiment. In this embodiment, in order to facilitate the combination of the button 220 and the visor 230® above the elastic piece 260, the opening on the visor 230 is bent to form a convex embedded portion 231, and the embedded portion 231 is embedded in the button 220. The elastic piece 260 has a flat plate shape and includes a pressure receiving portion 261 corresponding to the button 220. The bottom portion of the pressure receiving portion 261 is provided with a contact 2613, and the contact portion 2613 projects into the through hole in the frame plate 290. In use, the keycap 210 is pressed, and the button 220 is moved downward to the pressed portion 2613 of the top elastic piece 260 to elastically deform the elastic piece 260, and the contact 2613 turns on the circuit on the thin film circuit board 280. The upper surface of the light guide plate 240 constitutes a light-emitting portion 241. The light emitted from the light source 243 enters the light guide plate 240 to be expanded. The light is emitted from the light exit portion 241 after being scattered and homogenized. After the light passes through the permeable light-transmissive circuit board 280, the shelf 290 and the elastic piece 260, the light is blocked by the light-shielding sheet 230 at the portion where the light is not required, so that the light can only illuminate the button 220 and the key cap 210. Text and pattern areas to make efficient use of light. In the second embodiment, since the button 220 and the light shielding sheet 230 are integrated by the insert molding technology, the thickness of the metal light shielding sheet 230 and the combined button 220 can be thinner, thereby reducing the overall thickness of the backlight keyboard 200. Meet the requirements of thin design.综 In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application in accordance with the law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the present invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a backlit keyboard according to an embodiment of the present invention. 2 is a schematic diagram of a backlit keyboard according to Embodiment 2 of the present invention. ® [Main component symbol description] Backlit keyboard 100 ' 200 key cap 110 , 210 button 120 , 220 key top 121 connecting portion 123 pressing portion 125 light shielding sheet 130 , 230 light guide plate 140 , 240 light emitting portion 141 , 241 through hole 142 light Face 143 bottom surface 145 side wall 147 light source 148, 243 14 201015602. spring piece 160, 260 base 161. pressure receiving portion 162 ' 261 contact 164, 2613. embedded portion 231 thin film circuit board 280 shelf 290
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