200419220 玖、發明說明： 【發明所屬之技術領域】 本發明係關於一種透反射式顯示器及背照系統。透反射 式顯示器乃屬能在反射及透射中運作之顯示器。於反射中， 顯示器上的圖像資訊通常利用周圍光顯現，而在透射中則 利用背照系統，背照系統僅在周圍光位準在反射模式中太 低無法提供適度觀賞時始加採用。為獲顯示器可兼於透射 及反射中操作起見，透反射式顯示器含一透反射器，該透 反射器基本上係一半透明鏡，將入射其上之光部分透射並 邵分反射。與純反射式顯示器相較，於反射中操作之透反 射式顯示器亮度不足，蓋透反射器使大部分周園光得以透 射，然後即行消失無法供觀賞顯示器上的圖像資訊。與純 透射式顯示器相較，於透射中操作之透反射式顯示器亮度 較差’因透反射器僅部分透射由背照所放射之光。此種效 差而欠党更屬彩色透反射式顯示器中的一大問題，緣於在 此等顯示器中大量之光亦於彩色濾光器中被吸收之故。藉 降低透反射器之透射以供透反射式顯示器更強反射光方面 為更強力背照系統’俾於透反射式顯示器在透射運作中時 保持亮度。 【先前技術】 歐洲專利申請案第877282號試圖改進透反射式顯示器之 亮度與效率。其中所揭示之顯示器包含一液晶面板，一配 置於該面板後方之透反射益以及配置於透反射哭後方之背 照組合。為提高該顯示器的效率，歐洲申請案877282號建 86168 200419220 議採用-反射式極化器以配合具有吸光能力之背…。 不過反射式極化器係屬相當複雜而昂貴之光學組件。而且 具有吸光能力之背照組合却有背照放射之光部分被吸收而 降低顯π詻用於透射時之效率的缺點。 【發明内容】 次第含有： -透反射式光閥； 本發明之主要目的在於提供—種透反射式顯示器，其於 透射或反射模式或兩者兼具之操作時，皆有效而明亮。 此目的係利用—種透反射式顯示器而達成者，該顯示器 •透反射為；及 -一背照系統； 該背照系統次第包含： -一第一四分波阻滞器； -適於放射線性極化光之透明線性極化發光之光源； -第二四分波阻滯器；以及 -一反光表面。 孩背照系統與透反射器協同以高效率方式提供環形極化 光至透反射式光閥，從而提供透射很有效率之透反射式顯 示裝置。此南效率乃由利用背照系統之四分波阻滞器及反 光表面以回收透反射器所反射出之光而達成。由於背照系 統之組件皆不吸收光，至少理論上均屬理想組件，則回收 可使全部自線性極化發光之光源之光供至透反射式光閥。 而且’透反射器之透射僅決定在透反射器將光透射前之循 86168 200419220 環的平均數。故透反射器背照系統之效率大致與透反射器 的透射無關。從而可降低透反射器的透射以改善反射中的 亮度’同時維持透射中的亮度。尤其在反射中，透反射式 顯示器基本上其效率與明亮如一純反射式裝置，蓋背照系 統不會吸收或改變入射其上之周遭光的極化性。 為改善透反射式顯示器於透射中之對比起見，在一較佳 具體實例之透反射式裝置中，該線性極化發光光源以適應 背照系統之透反射器側之放射線性極化光為先。 自線性極化發光光源向反光表面之光經反光表面到達透 反射器，且於其呈現該透反射器時，具有與直接導向透反 射器之光的旋向性互補之旋向性。由於透反射式光閥通常 適應之功能為一極化成分之光閥，其它成分通常就光閥之 啟閉而透射，故出現在透反射器處具互補旋向性之光降低 透反射式顯示器之對比。此種對比的損失，只要線性極化 發光光源優先放射至透反射器一方時，即可避免或至少獲 得減輕。達成此優先耦出的方法屬業界所熟知，其中之一 為洋雕結構之搞出表面。 入適當旋向200419220 (1) Description of the invention: [Technical field to which the invention belongs] The present invention relates to a transflective display and a backlighting system. A transflective display is a display that works in both reflection and transmission. In reflection, the image information on the display is usually displayed using ambient light, while in transmission, a backlight system is used. The backlight system is only used when the ambient light level is too low in reflection mode to provide moderate viewing. In order that the display can operate in both transmission and reflection, a transflective display includes a transflector, which is basically a semi-transparent mirror that transmits and partially reflects light incident on it. Compared with a pure reflective display, a transflective display operating in reflection is not bright enough. Covering the transflective reflector allows most of the garden light to be transmitted, and then disappears immediately, making it impossible to view the image information on the display. Compared to a purely transmissive display, a transflective display operating in transmission is less bright because the transflector only partially transmits the light emitted by the backlight. Such inefficiency is a major problem in color transflective displays because a large amount of light in these displays is also absorbed in color filters. By reducing the transmission of the transflective to provide a more reflective light for the transflective display, a more powerful backlight system is used to maintain the brightness of the transflective display during transmission. [Prior Art] European Patent Application No. 877282 attempts to improve the brightness and efficiency of a transflective display. The display disclosed therein includes a liquid crystal panel, a transflective benefit disposed behind the panel, and a backlight combination disposed behind the transflective element. In order to improve the efficiency of the display, European application No. 877282 86168 200419220 proposes the use of a reflective polarizer to match the back with light absorption ... However, reflective polarizers are quite complex and expensive optical components. In addition, a back-illuminated combination with light-absorbing ability has the disadvantage of partially absorbing the light emitted from the back-illuminated light, which reduces the efficiency when the π 詻 is used for transmission. [Summary of the invention] The second time contains:-transflective light valve; the main object of the present invention is to provide a transflective display, which is effective and bright when operating in transmissive or reflective mode or both. This objective is achieved by using a transflective display, which is a transflective display; and-a back-illuminated system; the back-illuminated system includes:-a first quarter wave blocker;-suitable for radiation A transparent linearly polarized light source of polarized light;-a second quarter wave blocker; and-a reflective surface. The back-illuminated system works in conjunction with a transflector to provide circularly polarized light to a transflective light valve in a highly efficient manner, thereby providing a transflective display device with a very efficient transmission. This southern efficiency is achieved by using the quarter-wave blocker and the reflective surface of the back-illuminated system to recover the light reflected by the trans-reflector. Since the components of the back-illuminated system do not absorb light, at least in theory, they are ideal components. Recycling allows all the light from the linearly polarized light source to be supplied to the transflective light valve. And the transmission of the 'transflector' only determines the average number of loops before the transflector transmits light. Therefore, the efficiency of the transflector back-illuminated system is roughly independent of the transmission of the transflector. It is thus possible to reduce the transmission of the trans-reflector to improve the brightness in the reflection 'while maintaining the brightness in the transmission. Especially in reflection, a transflective display is basically as efficient and bright as a purely reflective device. The cover-back illumination system does not absorb or change the polarization of the surrounding light incident on it. In order to improve the contrast of the transflective display in transmission, in a transflective device of a preferred embodiment, the linearly polarized light source is adapted to emit linearly polarized light on the transflector side of the back-illuminated system as first. The light from the linearly polarized light-emitting light source to the reflective surface passes through the reflective surface to the transreflector, and when it presents the transreflector, it has a rotational direction that is complementary to the rotational direction of the light directly directed to the transflector. Since the transflective light valve is usually adapted to a light valve with a polarized component, the other components are usually transmitted when the light valve is opened and closed, so the light with complementary rotation in the transflector appears to reduce the transflective display. The contrast. This loss of contrast can be avoided or at least mitigated as long as the linearly polarized light source emits light preferentially to the transflector side. The method of achieving this preferential coupling is well known in the industry, one of which is to create the surface of the foreign carving structure. Into proper rotation
制不良鏡效應’最好亦具有若干擴散反射性。 為回收由背照系統所放射及自透反射器反射 性光内之光，反光表面將入射並μ 士止, 可在線性極化發光 為獲致相當平整之透反射式顯示器， 86168 200419220 光源對面採用一側照（邊緣照射）線性發光波導，其中將燈配 置於反射器與透反射器兩者間光之路徑中。 部分透射且部分反射之透反射器宜具有百分之二十以下 之透視率以便用周遭光獲最佳觀視度。最好該透反射器具 有面朝背照系統之反射表面，此反射表面具銀製或銀合金 之表面。銀或銀合金表面之反射率通常高於鋁製者。由於 回收光數度入射於透反射器上之結果，故有利於採用此一 高效率反射表面。此外，若該透反射器含有一適於將入射 其上之光部分反射部分透射之介質鏡時，即可獲一高效率 透反射器。 高亮度及高效專在彩色透反射式顯示器而言特具重要 性，蓋此等顯示器含有將大部分入射光吸收之彩色濾光器 之故由於本發明之諸顯示器提供此一高效率及高亮度， 就含此等彩色濾光器之顯示器而言，本發明即具特別重要 性。為可兼用於反射式及透射式模式，彩色濾光器通常配 置於透反射器之觀視的一邊上。 本發明並關於一種背照系統，特別是用於本發明透反射 式顯π器中之背照系統。依據本發明，該背照系統次第包 含： -第一四分波阻滯器； -適於放射線性極化之透明線性極化發光光源； •第二四分波阻滞器；以及 -一反光表面。 本發明並關於-種透反射式顯示器，其次第包含·· 86168 200419220 -一透反射式光閥； -一透反射器；及 •一背照系統； 此背照系統次第包含： -一透明側照式環形極化發光波導；及 -一反光表面。 若使背照系統含一透明側照式環形極化發光波導，即可 獲致與含具線性極化光源之透反射式顯示器相同功能之透 反射式顯示器。此種背照系統組件較少，故設計簡單且產 製經濟。： 一如含線性極化發光背照之透反射式顯示器，該環形極 化發光光源最好適應背照系統透反射器側之放射極化光， 及/或與具百分之二十以下透射率之透反射器配合，及/或與 具有銀或銀合金屬且面向背照系統之反射表面之透反射器 配合，及/或與含適於將入射光部分反射且部分透射之介質 鏡的透反射器配合，及/或用於含彩色濾光器之透反射式顯 示器中。 * · · . _ ‘ 側照環形極化發光波導可由組合透明波導基板及膽固醇 層（其屬膽固醇的序化層）而成，選定其傾度以使入射於該膽 固醇層上具可見光譜範圍中波長之波導光而言，第一旋向 性的環形極化成.分經選擇性地反射，而與第一互補之第二 旋向性的環形極化成分屬選擇性地透射。 【實施方式】 本發明之此等及他等方面，參閱下文中圖式及具體實例 86168 -10- 200419220 說明當可一目了然。 簡略顯示本發明透反射式顯示器—具體實例之橫切面 圖。此透反射式顯示器⑴次第包含—透反射式光閥⑺一透 反射器(4)及一背照系統⑷。該光閥⑺適於與透反射器⑷ 配合而於啟與閉或接通與關斷間’就周遭光及/或背照系統⑹ 所發之光，進行反向地電性轉換4本具體實例中，尚有 - 擇該透反射式光閥（2)含有一線性（二色）極化器 (16)、一四分波阻滞器（18)及一液晶室（2〇广用於液晶室（2〇) 之液晶效應及四分波阻滯器（18)具有併合效應，在接通狀態 提供"0"或半波阻滯（或其倍數），而在關斷狀態提供四分波 阻滯。 背照系統次第包含第一四分波阻滯器（8)，含燈（11)之 線性極化發光波導（10)，第二四分波阻滯器（12)及一反光表 面（14)。該線性極化發光光源（1〇)適於放射ΠρΠ極化光。尤 其為改善透射模式中之對比，該線性極化發光光源宜將光 放射至背照系統（6)之透反射器的一邊。 圖2概略顯示由背照系統所放射且於接通狀態經由圖1透 反射式顯示器傳播之光線的,軌跡。 在透射運作中，即背照系統（6)轉換至接通狀態，由線性 極化發光光源射向透瓦射器（4)之光線（3丨）經線性極化（在本 具體實例中光源放射"Ρ"極化光，而顯然，，s，，極化光同樣可 能）’並入射於第一四分波阻滯器上，而將”ρ，，極化光轉 換成右旋環形極化光線（3 1)(採用具相反極性可獲左旋環形 極化光然後右旋極化光線（31)即入射於透反射器（4)上。 86168 -11- 200419220 該透反射器（4)屬部分透射部分反射，而將光線（31)分裂成 透射光線（33)及反射光線（35)。由於透反射器之反射配置為 鏡式，故旋向性依反射而倒轉，且反射之光線（35)呈左旋環 形極化。為說明晰起見，該反射之光線（3 5)在圖中與光線（31) 相對移位。在通過四分波阻滯器（8)中，反射之右旋光線（3 5) 成為”sfl極化，然後由透明線性極化發光光源（1〇)透射，並 由四分波阻滯器（12)將之轉換成左旋環形極化光。該左旋光 線（35)即由反射表面（14)反射以形成光線（37)。因反光表面 (14)至少部分呈鏡面反射，故光線（37)呈右旋環形極化。此 右旋極化光線（37)由四分波阻滯器（12)將之變成”p”極化， 並由透明線性極化發光光源（1〇)原樣透射。現在光線（37)在 光線（31)原始地位，因此，顯然此同一光徑一次次追溯，以 獲更多正確極化之光呈現於透反射式液晶室。此項回收法 之最終成果為在理論上，全部背照系統射向透反射器之光 最終由透反射器·透射，.而其效率至少理論上不計各相關組 件之非理想性下為百分之百。此外，光線（3丨）及（37)乃環形 極化，尤其在本具體實例中為右旋環形極化，故無需進一 步極化裝置以使光為透反射式光閥（2)所適宜使用。而且， 透反射器之透射卑僅影響回收光線透射前之平均次數，而 不太影響透反射器（4)與背照系統⑹兩者組合的效率。因 此，可降低透反射器（4)的透射率以增強透反射式顯示器反 射模式中之亮I，同時大致保持透射模式中之相同” 效率。 、 該由透反射器⑷所透射並以光（33)及（37)所表示之右旋光 86168 -12- 200419220 入射於液晶室（20)上。液晶室（20)經配置而使之與四分波阻 滞器（18)共同具有在接通狀態提供”〇”或半波阻滯（或其倍數） 的組合效應，且該由透反射器（4)所透射之光徑液晶室（20) 及四分波阻滞器（18)透射，極化上並無改變。該右旋環形極 化光由同量之”s”極化及”p”極化光組成，該”s”極化成分由 極化器（16)吸收以產生可呈現給觀賞器之” p，，極化光線。因 此’在接通狀態該透反射式顯示器呈現光亮。 圖3概略顯示由背照系統所放射且於關斷狀態經圖1透反 射式顯7F咨之光的軌跡。 光線（31)之光路徑與圖2中所示者相同。現在液晶室（20) <狀態為液晶室（2〇)與四分波阻滯器（18)之組合效應呈四分 波阻滯’由背照系統（6)所提供之右旋環形極化光線（33)及 (3 7)轉換成”s”極化光。此”s"極化光由二色極化器（16)吸收。 光線無法到達觀賞器故透反射式顯示器呈現黑暗。 圖4概略顯示經由圖i之透反射式顯示器在接通狀態下周 遭光線所傳播之軌跡。 在透反射式顯示器（1)於反射之操作時，周遭未經極化之 光線（41)由二色極化器（16)轉變成"p”極化光線。該液晶室（2〇) 經配置以使液晶室（2〇)與四分波阻滯器（18)配合而具有於接 通狀怨下’提供”〇”或半波阻滯（或其倍數）之組合效應，由 極化器（16)所透射之光經液晶室（20)及四分波阻滞器（18)透 射，其極化並無改變，”p”極化光線（41)入射於透反射器（4) 上。鏡面反射並不改變線性極化光之極化，故反射光線(43) 仍屬” P”極化。液晶室（2〇)及阻滯器（18)並不影響該光線(43) 86168 -13- 200419220 之極化，’’ρπ極化光入射於二色極化器（16)上且極化與二色 極化器（1 6)之透射軸排列一致，則光線（43)即能到達觀賞 器。 由透反射器（4)所透射之光線（45)使之呈"ρ"極化，然後相 繼由四分波阻滞器（8)轉換成右旋環形極化光線（45)，不受 線性極化發光光源（10)影響而以不改變極化透射，由四分波 阻滯器（12)轉換成πρπ極化之光線。線性極化光之極化不會 改變自鏡反射面之反射，故反射光線（47)呈，，ρ"極化。此光 線（47)以與光線（45)類似方式，於次第通過四分波阻滞器 (12)、線性極化發光光源（1〇)、四分波阻滯器（8)以及透反射 器（4)等之後，呈現於液晶室（2〇)為一極化光線。顯然，自 圖3可見，凡自透反射器（4)所反射至反光表面（14)之光線， 最終皆達觀賞器。 總之，圖3說明至少理論上該背照系統（6)及透反射器（4) 皆不會負面影響反射操作中透反射式顯示器（1)之亮度，理 論上’若各組件功能皆屬理想下，所獲亮度應與純反射式 顯示器者相同。 圖5概略顧示周遭光線通過圖1關斷狀態之透反射式顯示 器的軌跡。 以透反射式顯示器（1)於關斷狀態之反射操作中，未經極 化 <周遭光線（51)由二色極化器（16)將之變成"ρ，，極化，且 於液晶室（20)及四分波阻滯器（1 8)在關斷狀態中之組合效應 提供四分波阻滞時，光線（53)出現為一左旋環形極化光線 (53)。當鏡反射表面於反射期改變入射其上之光的旋向性 86168 200419220 時，自透反射器（4)之反射產生一右旋光線（53)。如參考圖3 所說明，在關斷狀態中，右旋環形極化光由液晶室（2〇)及阻 滯器（18)將之轉換成ns’’極化光，然後由透反射式光閥（2)之 二色極化器（16)吸收。 由該透反射器（4)所透射之光線（55)保持左旋極化，然後 由四分波阻滯器（8)予以”s’’極化，不受線性極化發光光源（10) 影響而在不改變極化下透射，由四分波阻滯（12)轉換成左旋 極化光，於鏡光反射表面（14)之後，轉換成右旋極化光線 (5 5)，此光線（55)即相繼由四分波阻滯器（12)轉換至”p”極化 光，由線性極化發光光源（1〇)以不改變極化而透射，由四分 波阻滯器（8)轉換成右旋極化光，以及由透反射器（4)以不改 變極化而透射，以產生一如上述由透反射式光閥（2)所完全 吸收之右祿極化光線。右旋光線（55)自透反射器（4)反射後 之光線再呈左旋極化。 總之，此透反射式顯示器（1)呈現黑暗，特別是暗至純反 射式顯示器程度，證實透反射器（4)及背照系統（6)對反射操 作中透反射式顯示器皆無負面影響。 在圖1之顯示器中，液晶室（2〇)經配置而與四分波阻滯器 (18)組合，以於接通狀態下提供零或半波阻滯或其倍數，而 於關斷狀態下提供四分波阻滯器。該四分波阻滯器（18)提供 四分波阻滯，該液晶室（2〇)應於接通狀態提供四分波阻滯（相 對於阻滯器（18)之正或負），而於關斷狀態提供零阻滯。提 供此等狀態之室的範例係熟知之電控雙折射室，其包含佈 置於透明電極間之單軸導向列液晶層，單料向與 86168 -15- = 1Τ)之透射轴成四十五度。除電控雙折射室外， 合，或鐵電液以。 換式四分波阻滯器之組 在反射閥⑺《類型並無關鍵性。凡與透反射器協同 ，W中利用未極化之周遭光，於亮與暗狀態間變換， 且透射操作中利用環形極化光於亮與暗狀態間變換之透 反射式光閥皆可使用。例如’亦可採用扭曲式向列室。具 -有四切之彩色超扭曲式向列室含有人百三十奈米與扭It is also preferable that the "mirror effect" has some diffuse reflectivity. In order to recover the light radiated by the back-illuminated system and reflected light from the transflective reflector, the reflective surface will be incident and μ stop. It can emit light in linear polarization to obtain a fairly flat transflective display. 86168 200419220 Opposite the light source A side-illuminated (edge-illuminated) linear light-emitting waveguide in which a lamp is arranged in the path of light between a reflector and a trans-reflector. Partially transmissive and partially transmissive transflectors should have a transmittance of less than 20% in order to obtain the best viewing with ambient light. Preferably, the transflective appliance has a reflective surface facing the back-illuminated system, the reflective surface having a surface made of silver or a silver alloy. The reflectivity of silver or silver alloy surfaces is usually higher than that of aluminum. Because the recovered light is incident on the transflector several degrees, it is advantageous to use this highly efficient reflective surface. In addition, if the transflector includes a dielectric mirror adapted to transmit a partially reflecting portion of light incident thereon, a high-efficiency transflector can be obtained. High brightness and high efficiency are especially important for color transflective displays. Covering these displays includes a color filter that absorbs most of the incident light. The displays of the present invention provide this high efficiency and high brightness. The present invention is particularly important for displays containing these color filters. To be used in both reflective and transmissive modes, color filters are usually placed on the viewing side of the transflector. The present invention also relates to a back-illuminated system, particularly a back-illuminated system used in the transflective display of the present invention. According to the invention, the back-illuminated system includes:-a first quarter wave blocker;-a transparent linearly polarized light source suitable for emitting linear polarization; a second quarter wave blocker; and-a reflective light surface. The invention also relates to a type of transflective display, which secondly includes: 86168 200419220-a transflective light valve;-a transflective reflector; and a back-illuminated system; this back-illuminated system includes:-a transparent side Illuminated circularly polarized light emitting waveguide; and-a reflective surface. If the back-illuminated system includes a transparent side-illuminated circularly polarized light-emitting waveguide, a transflective display having the same function as a transflective display with a linearly polarized light source can be obtained. This back-illuminated system has fewer components, so it is simple to design and economical to produce. : Just like a transflective display with a linearly polarized luminous back-light, the circularly polarized luminous light source is best adapted to the radiated polarized light on the transflector side of the back-illuminated system, and / or has a transmittance of less than 20% With a transflective reflector, and / or with a transreflector with silver or silver metal facing the reflective surface of the back-illuminated system, and / or with a transmissive lens containing a dielectric mirror suitable for partially reflecting and partially transmitting incident light Reflector mating and / or use in transflective displays with color filters. * · ·. _ 'Side-illuminated circularly polarized light-emitting waveguides can be formed by combining a transparent waveguide substrate and a cholesterol layer (which is a serialized layer of cholesterol), and the inclination is selected so that the incident wavelength on the cholesterol layer has a wavelength in the visible spectral range. As for the waveguide light, the first circularity of the circularity is polarized into. The partial reflection is selectively reflected, and the second circularity of the circularity that is complementary to the first is selectively transmitted. [Embodiment] For these and other aspects of the present invention, please refer to the following drawings and specific examples 86168 -10- 200419220 to explain at a glance. A schematic cross-sectional view of a transflective display of the present invention-a specific example is shown briefly. This transflective display includes, for the first time, a transflective light valve, a transflector (4), and a back-illuminated system. The light valve ⑺ is suitable for cooperating with the transflective reflector 启 to open and close or switch on and off the light emitted by the surrounding light and / or the backlight system 反向, and perform the electrical conversion in the reverse direction. In the example, there is still-the transflective light valve (2) contains a linear (two-color) polarizer (16), a quarter wave retarder (18) and a liquid crystal cell (20 The liquid crystal effect of the liquid crystal chamber (20) and the quarter-wave retarder (18) have a merging effect, providing "" 0 " or half-wave retardation (or multiples thereof) in the on state, and providing four The back-illuminated system includes the first quarter-wave blocker (8), the linearly polarized light-emitting waveguide (10) including the lamp (11), the second quarter-wave block (12), and a Reflective surface (14). The linearly polarized light source (10) is suitable for emitting ΠρΠ polarized light. Especially to improve the contrast in the transmission mode, the linearly polarized light source should emit light to the back-illuminated system (6) Fig. 2 schematically shows the trajectory of the light emitted by the back-illuminated system and propagating through the transflective display of Fig. 1 in the on state. During the transmission operation, that is, the back-illuminated system (6) is switched to the on state, and the light (3 丨) from the linearly polarized luminescent light source to the penetrator (4) is linearly polarized (in this specific example, the light source emits light) " Ρ " polarized light, and obviously, s, polarized light is also possible) 'and incident on the first quarter wave blocker, and "ρ," polarized light is converted into a right-handed circular pole (3 1) (Using reverse polarity to obtain left-handed circularly polarized light and then right-handedly polarized light (31) is incident on the transflector (4). 86168 -11- 200419220 The transflector (4) It belongs to partial transmission and partial reflection, and splits the light (31) into transmitted light (33) and reflected light (35). Since the reflection of the transflector is configured as a mirror, the rotation is reversed by the reflection, and the reflected light (35) is left-handed circularly polarized. For the sake of clarity, the reflected light (3 5) is relatively shifted from the light (31) in the figure. In the passage through the quarter wave blocker (8), the reflected light The right-handed light (3 5) becomes "sfl polarized", and then transmitted by a transparent linearly polarized light source (1〇), and divided by four The blocker (12) converts it into left-handed circularly polarized light. The left-handed light (35) is reflected by the reflective surface (14) to form light (37). Since the reflective surface (14) is at least partially mirror-reflected, The light (37) is right-handed circularly polarized. This right-handed polarized light (37) is turned into "p" polarization by a quarter wave blocker (12), and is made of a transparent linearly polarized light source (1〇 ) Is transmitted as it is. Now the light (37) is in the original position of light (31). Therefore, it is clear that the same light path is traced back and again to get more correctly polarized light to appear in the transflective liquid crystal cell. The final result is that, in theory, all the light from the back-illuminated system to the transflector is ultimately transmitted by the transflector, and its efficiency is at least 100% theoretically excluding the non-idealities of the related components. In addition, the light rays (3 丨) and (37) are circularly polarized, especially in this specific example, they are right-handed circularly polarized, so no further polarization device is needed to make the light suitable for the transflective light valve (2). . Moreover, the transmission of the transflector only affects the average number of times before the recovered light is transmitted, and does not affect the efficiency of the combination of the transflector (4) and the back-illuminated system. Therefore, the transmittance of the transflective reflector (4) can be reduced to enhance the bright I in the reflective mode of the transflective display, while maintaining substantially the same "efficiency" in the transmissive display. The light transmitted by the transflector ⑷ is light ( The right-handed light 86168 -12- 200419220 indicated by 33) and (37) is incident on the liquid crystal cell (20). The liquid crystal cell (20) is configured so that it shares a connection with the quarter wave blocker (18). The on-state provides the combination effect of "〇" or half-wave retardation (or multiples thereof), and the light path liquid crystal cell (20) and quarter-wave retarder (18) transmitted by the transflector (4) transmit There is no change in polarization. The right-handed circularly polarized light is composed of the same amount of "s" polarization and "p" polarization, and the "s" polarization component is absorbed by the polarizer (16) to produce Can be presented to the viewer's "p", polarized light. Therefore, the transflective display appears bright in the on state. Fig. 3 schematically shows the trajectory of the light emitted by the back-illuminated system through the transflective display 7F in Fig. 1 in the off state. The light path of the ray (31) is the same as that shown in FIG. The liquid crystal cell (20) is now < the state is that the combined effect of the liquid crystal cell (20) and the quarter wave blocker (18) is a quarter wave block. The right-handed circular pole provided by the back-illuminated system (6) The converted rays (33) and (3 7) are converted into "s" polarized light. The "s " polarized light is absorbed by the two-color polarizer (16). The light cannot reach the viewer, so the transflective display appears dark. Figure 4 shows schematically the surrounding light when the transflective display shown in Figure i is on. The transmitted trajectory When the transflective display (1) is operating in reflection, the surrounding unpolarized light (41) is transformed from a two-color polarizer (16) into " p "polarized light. The liquid crystal cell (20) is configured so that the liquid crystal cell (20) cooperates with the quarter wave blocker (18) to have a "provide" of "0" or a half-wave block (or a multiple thereof) under the connection state. ) Combination effect, the light transmitted by the polarizer (16) is transmitted through the liquid crystal cell (20) and the quarter wave retarder (18), and its polarization is not changed, and the "p" polarized light (41) Incident on the transflector (4). The specular reflection does not change the polarization of linearly polarized light, so the reflected light (43) is still "P" polarized. The liquid crystal chamber (20) and the retarder (18) do not affect the polarization of the light (43) 86168 -13- 200419220, and the ρπ polarized light is incident on the two-color polarizer (16) and polarized. In accordance with the arrangement of the transmission axis of the two-color polarizer (16), the light (43) can reach the viewer. The light (45) transmitted by the trans-reflector (4) makes it " ρ " polarized, and is successively converted into right-handed circularly polarized light (45) by the quarter wave blocker (8). The linearly polarized light source (10) affects the transmission without changing the polarization, and is converted into πρπ-polarized light by the quarter wave blocker (12). The polarization of linearly polarized light will not change the reflection from the mirror reflection surface, so the reflected light (47) is,, ρ " polarized. This light (47) passes through the quarter wave blocker (12), the linearly polarized light source (10), the quarter wave blocker (8), and the transflector in a similar manner to the light beam (45). (4) After waiting, the liquid crystal cell (20) appears as a polarized light. Obviously, it can be seen from Fig. 3 that all the light reflected by the transflective reflector (4) to the reflective surface (14) finally reaches the viewer. In summary, Figure 3 illustrates that at least in theory neither the back-illuminated system (6) nor the transflective (4) will negatively affect the brightness of the transflective display (1) in reflective operation. In this case, the obtained brightness should be the same as that of a purely reflective display. Fig. 5 schematically shows the trajectory of ambient light passing through the transflective display in the off state of Fig. 1. In the reflective operation of the transflective display (1) in the off state, the unpolarized < surrounding light (51) is changed to " ρ by the two-color polarizer (16), polarized, and When the combined effect of the liquid crystal cell (20) and the quarter-wave retarder (18) in the off state provides quarter-wave retardation, the light (53) appears as a left-handed circularly polarized light (53). When the reflective surface of the mirror changes the rotation of the light incident on it during the reflection period 86168 200419220, the reflection from the transflective reflector (4) produces a right-handed ray (53). As explained with reference to FIG. 3, in the off state, the right-handed circularly polarized light is converted into ns '' polarized light by the liquid crystal cell (20) and the retarder (18), and then transmitted by the transflective light. The two-color polarizer (16) of the valve (2) absorbs. The light (55) transmitted by the transflector (4) maintains left-handed polarization, and is then "s" polarized by the quarter wave blocker (8), and is not affected by the linearly polarized light source (10). And transmitted without changing the polarization, it is converted into left-handed polarized light by the quarter wave retardation (12), and after the mirror light reflecting surface (14), it is converted into right-handed polarized light (5 5). This light ( 55) That is, the "p" polarized light is successively converted by the quarter wave blocker (12), transmitted by the linearly polarized light source (10) without changing the polarization, and the quarter wave blocker (8) ) Is converted into right-handed polarized light, and transmitted by the transflector (4) without changing polarization, so as to generate right-polarized light completely absorbed by the transflective light valve (2) as described above. The rotating light (55) reflects left-handed polarization after being reflected from the transflective reflector (4). In short, this transflective display (1) appears dark, especially dark to a purely reflective display, confirming that the transflector (4 ) And backlight system (6) have no negative impact on the transflective display in reflective operation. In the display of Figure 1, the liquid crystal chamber (2) is equipped with It is combined with a quarter wave blocker (18) to provide zero or half wave block or a multiple thereof in the on state, and a quarter wave blocker in the off state. The quarter wave blocker The retarder (18) provides four-wave retardation. The liquid crystal cell (20) should provide four-wave retardation in the on state (relative to the positive or negative of the retarder (18)), and in the off state. Provides zero retardation. An example of a chamber providing these states is the well-known electrically controlled birefringence chamber, which includes a uniaxially oriented liquid crystal layer arranged between transparent electrodes, with a single direction of transmission and 86168 -15- = 1T). The axis is forty-five degrees. In addition to the electronically controlled birefringence outdoor, hybrid, or ferroelectric liquid. The type of the switchable quarter wave blocker is not critical in the type of the reflection valve. In cooperation with the transflector, Transmissive light valves that use unpolarized ambient light to switch between light and dark states and use circularly polarized light to switch between light and dark states in transmission operations can be used. For example, 'distortion can also be used Nematic room. With-four-colored super-twisted nematic room containing one hundred and thirty nanometers and twisted
阻滞器層組合之阻滯層者(業界皆知如此)可供採用。就薄膜 電晶體有源矩卩車途晶顧一 工A 、 』斤兜1早，夜日日顯不态而舌，一六十度扭曲構件（TN) 室可屬合宜使用。 該透反射器（4)可用做如圖2所示自透反射式光闕⑺分立 之、，且件或與透反射式光閥統合，利用電極而適於將入射 其上之光部分透射而部分反射。本具體實例之運作已以二 元之接通與關斷狀態中說明，不過此點並不具重要性，灰 色層級正以傳統方式實施。此透反射式光閥（？）可含單一閥 或多個光閥。尤其是光閥可含多個獨立定址式光閥。此等 光閥可經配置以構成顯示細胞，或配成矩陣以獲無源矩陣 或有源矩陣，其中每一個別定址式光閥皆由一薄膜電晶體 或薄膜二極體所激勵。而且，此等光閥可與漉色器組合而 獲一多彩色或全彩色之透反射式顯示器（丨）。由於濾色器通 常吸收大部分入射光（例如含紅、綠、黃色域之濾色器通常 吸收三分之一入射光），故在彩色透反射式顯示器中，效率 與亮度具特別重要性。為了濾色器兼用於反射及透射，濾 86168 -16- 200419220 色器常配置於透反射器（4)的收視邊。 此透反射器（4)對入射光部分透射而部分反射。透反射器 本身屬即知，此等即知之透反射器宜用於本發明之透反射 式顯π器中。例如，該透反射器可屬一透明基板，諸如玻 璃或透明合成樹脂等，並於其一邊或相對兩邊上配置如金 屬層之反光層。透反射器的透射率可藉改變該金屬層的厚 度而碉諧之。另外，金屬層依據圖案覆蓋基板，改變覆蓋 金屬的百分比以調諧透射率。理論上，透反射器之透射 率應儘量降低，蓋如以上圖2及圖3之說明，無論限定之透 射率若何，背照系統（6)確保其所放射之全部光最終皆呈現 至透反射式光閥（2)，從而於反射中當透射率降低時有更多 周遭光供用。因此，透射率可為百分之五十以下，而以百 分之二十以下較佳。另一方面，由於背照系統（6)之組件以 及透反射器本身不夠理想，若干程度之光損失無法避免者 例如介面處之寄生反射及反光表面處吸收等，實務上以限 制回收由光源（10)放射之光的次數為宜，此等限制以增高透 反射器（4)的透射率即可達成。金屬層可由任何金屬所製， 諸如鋁等。不過，由於光源（1〇)放射之光自透反射器（4)數 次反射，而每次皆有若干光吸收入金屬層，故最好採用銀 或銀合金之金屬表面。銀及銀合金層以吸光性低著稱。透 反射器（4)亦可含一介質鏡，此等鏡係業界所熟知者。此等 介質躁之優點在於大致無吸光性。 該背照系統（6)含第一及第二兩個四分波阻滞器（8 I])。 此等阻滯器為技術界所熟知。此第一及第二四分波阻滯哭 86168 -17- 200419220 之旋向性能互相獨立選定。 該線性極化發光光波導（1〇)適於放射線性極化光。其宜將 光射至背照系統（6)的透反射器一邊。若圖丨之線性極化發光 光源（10)將一 πρπ極化光線射向反光表面（14)，則在關斷狀 態下，此一光線最終以”ρ”極化呈現至極化器（16);由於此 方向與極化器（16)之透射軸合同，故此一光線能到達如關斷 狀態中所欲之顯示器呈現黑暗。宜以線性極化發光光源（i 〇) 放射至透反射器邊而抑制此對比降低。而且此線性極化發 光源（10)係屬透明，以使自透反射器反射之光到達反光 表雨（14)，反之亦然。 圖1中所示之線性極化發光光源（1〇)乃屬側照式線性極化 發光光源。此型光源實屬較佳但非必要。另一允宜型式之 線性極化發光載於EP 606939中。其中所揭示之線性極化發 光光源含有配置於寬帶固醇極化器與一光反射器兩者間的 燈。在本系統之背照系統中採用此種配置，其缺點在於該 燈及光反射器阻碍自透反射器（4)反射至反光表面（14)之光 的徑路，從而妨碍回收過程。尤其是需較厚顯示器。 在該較佳之側照式線性極化發光光源（10)中，燈配置於波 導的一侧，光經由波導的入口側面耦入。波導利用總内部 反射將光循波導而導引。光循此波導而於出口表面耦出， 此表面為波導之主要表面，其面向光要放射的一邊。藉由 含入適當極化選擇裝置，光選擇性地耦出極化作用。此種 線性極化發光光源乃屬已知。請參見US 5,729,3 11，US 5,84 5，03 5，WO 01/5 3 745 及 WO 01/90637。另外是在歐洲專 86168 -18- 200419220 利申w案案虓〇12〇3674·5(申請人參考號PHNL010690EPP)及 01203 666.1(申請人參考號pHNL〇1〇683Epp)中說明特別合宜 <具體實例。此等文件並提供適當方法以使波導允宜放射 至一邊’方法之一為提供具浮雕結構耦出表面之波導或採 槽式搞出表面之耦出元件之方式行之。 於環形極化光入射時，該反光表面（14)適於反轉其旋向 性。如技術界所熟知，鏡面反射式金屬表面提供此種反轉。 銘屬低成本之傳統選擇，但鋁具相當高的吸光性，故宜採 用銀或銀合金層之較低吸光性的表面。鑒於效率與亮度起 見’鏡面反射率愈高愈好。不過，為獲於收視角度範圍下 之舒適收視，最好具有一定程度之擴散反射率，譬如百分 之十或以下等。 圖1中諸組件雖經以互相間隔而繪製，但其不具重要性。 諸組件可允宜疊在一起構成一統合疊。而且諸組件可適當 統合以節省空間。 在圖1中所述之顯示器中，可用含有透明側照式環形極化 ‘ · . . 發光波導之背照系統以取代該背照系統，透明意指供入射 於波導主表面上之光之特別透明，入射光諸如自透反射器 及反光表面所反射之光。 侧照式線性極化發光波導可用透明波導基板與固醇層的 組合構成，選定固醇層的傾度以使可見波導光選擇性地反 射於波導基板與固醇層的介面處，從而獲得第一旋向性環 形極化光之反射束以及補充第一束之第二旋向性環形極化 光之透射束。技術方家皆知，依特定之背照設計，特別是 86168 -19- 200419220 固醇層與波導基板兩者折射率如何匹配上，該具第一旋向 性光束或具第二旋向性光束皆能以選擇方式耦出。 EP 606 940中所揭示之固醇層可適用以獲得為背照採用之 固醇層，但須選定傾度以使固醇層最宜在波導角度，而非 如EP 606 940中正常角度以選擇性地反射環形極化可見光入 射。傾度選定乃利用熟知之關係式入=n p C〇s $，其中”n„ 為固醇材料之平均折射率，’，ΡΠ為傾度而” <9，，為自正常角度 所測量之入射角。該非正常角度入射光所遭遇之傾度大於 正常入射光所遭遇者。因此，如果可見光於非正常入射角 選擇性地反射，尤其是於波導角度，則需將傾度減小。減 小傾度的有利後果在於該反射波長於正常入射處，移入或 移向紫外線範圍、使側照環形極化發光波導在可見光範圍 内更多透射性，其反射的結果，出現於液晶室之錯誤旋向 性先趨光受到抑制。 為使該側照環形極化發光波導對在正常或近乎正常角度 入射之光更具透射性，該波導基板可依據理想圖案配置分 互之耦出元件。此等耦出元件乃屬熟知，且由固醇系材料 構成。未為耦出元件所覆蓋之區域就正常或近乎正常入射 光而g係屬向透辦性。 為在固醇層與波導基板之介面處獲得有效反射，固醇層 或元件具最小厚度或高度，相當於構成固醇層或元件之固 醇材料傾度的四倍。標準厚度約一至十微米。 【圖式簡單說明】 圖1概略顯示本發明透反射式顯示器一具體實例之橫切面 86168 -20- 200419220 圖； 圖2概略顯示由背照系統所放射之光線，經過圖1之於接 通狀態透反射式顯示器時該光線的軌跡； 圖3概略顯示由背照系統所放射之光線，經過圖1之於關 斷狀態透反射式顯示器傳播時該光線之軌跡； 圖4概略顯示在周遭光線經圖1接通狀態之透反射式_示 器傳播時，該周遭光線之軌跡；以及 圖5概略顯示周遭光線經圖1關斷狀態之透反射器顯示器 通過之軌跡。 【圖式代表符號說明】 1 透反射拭顯示器 2 透反射式光閥 4 透反射器 6 背照系統 8 第一四分波阻滯器 1 〇波導 11燈 12第二四分波阻滞器 14反光表面 1 ό極化器 18 四分波阻滞器 20 液晶室 31光線 33透射光線 86168 -21 - 反射光線 光線. 周遭未極化光線 反射光線 右旋極化光線 反射光線 周遭光線 左旋極化光線 右旋極化光線 -22-Blockers of the blocker layer combination (known in the industry) are available. As far as the thin film transistor is active, the car's transistor A, “Jin Dou” is early in the morning, and every day, it ’s stubborn. One to sixty degree twisted member (TN) room is suitable for use. The transflector (4) can be used as a separate self-transflective light barrier as shown in FIG. 2 and can be integrated with a transflective light valve. The electrode is suitable for transmitting the light incident on it. Partial reflection. The operation of this specific example has been described in a binary on and off state, but this point is not important and the gray level is being implemented in a traditional way. This transflective light valve (?) Can contain a single valve or multiple light valves. In particular, light valves can contain multiple independently addressed light valves. These light valves can be configured to form display cells, or they can be arranged in a matrix to obtain a passive matrix or an active matrix, where each individual addressing light valve is excited by a thin film transistor or thin film diode. Moreover, these light valves can be combined with a color filter to obtain a multi-color or full-color transflective display (丨). Since color filters usually absorb most of the incident light (for example, color filters with red, green, and yellow domains usually absorb one third of the incident light), efficiency and brightness are of particular importance in color transflective displays. In order to use the color filter for both reflection and transmission, the 86168 -16- 200419220 color filter is often arranged on the viewing side of the transflector (4). This transflector (4) partially transmits and partially reflects incident light. Transflectors are known per se, and such known transflectors are suitable for use in transflective display devices of the present invention. For example, the transflector may be a transparent substrate, such as glass or transparent synthetic resin, and a reflective layer such as a metal layer may be disposed on one side or opposite sides. The transmittance of the transflector can be humorized by changing the thickness of the metal layer. In addition, the metal layer covers the substrate according to the pattern, and the percentage of the covered metal is changed to tune the transmittance. Theoretically, the transmittance of the trans-reflector should be reduced as much as possible. As described in Figure 2 and Figure 3 above, no matter what the limited transmittance is, the back-illuminated system (6) ensures that all the light emitted by it will eventually appear to be trans-reflective. Type light valve (2), so that when the transmittance decreases in reflection, there is more ambient light available. Therefore, the transmittance may be 50% or less, and more preferably 20% or less. On the other hand, because the components of the back-illuminated system (6) and the transflector are not ideal enough, some degree of light loss cannot be avoided, such as parasitic reflection at the interface and absorption at the reflective surface. In practice, the recycling by the light source ( 10) The number of times of the emitted light is appropriate, and these restrictions can be achieved by increasing the transmittance of the transflective reflector (4). The metal layer may be made of any metal, such as aluminum. However, since the light emitted by the light source (10) is reflected several times from the transflective reflector (4), and each time a certain amount of light is absorbed into the metal layer, it is preferable to use a metal surface of silver or a silver alloy. Silver and silver alloy layers are known for their low light absorption. The transflector (4) may also contain a dielectric mirror. Such mirrors are well known in the industry. These media have the advantage of being substantially non-absorptive. The back-illuminated system (6) includes first and second two quarter wave blockers (8 I)). These retarders are well known in the art. The first and second quarter-wave retardation choppers 86168 -17- 200419220 are selected independently of each other. The linearly polarized light-emitting optical waveguide (10) is adapted to emit linearly polarized light. It should direct light to the side of the transflector of the back-illuminated system (6). If the linearly polarized light source (10) in Figure 丨 emits a πρπ-polarized light toward the reflective surface (14), in the off state, this light is finally presented to the polarizer (16) with "ρ" polarization Since this direction is contracted with the transmission axis of the polarizer (16), this light can reach the display as dark as desired in the off state. A linearly polarized light source (i 〇) should be radiated to the side of the transreflector to suppress this decrease in contrast. In addition, the linearly polarized light source (10) is transparent, so that the light reflected from the transflective reflector reaches the reflective surface rain (14), and vice versa. The linearly polarized light source (10) shown in FIG. 1 is a side-illumination linearly polarized light source. This type of light source is better but not necessary. Another permissible version of linearly polarized light emission is contained in EP 606939. The linearly polarized light source disclosed therein includes a lamp disposed between a broadband sterol polarizer and a light reflector. The disadvantage of using this configuration in the back-illuminated system of this system is that the lamp and light reflector impede the path of light reflected from the transflective reflector (4) to the reflective surface (14), thereby hindering the recycling process. Especially thicker displays are needed. In this preferred side-illuminated linearly polarized light-emitting light source (10), the lamp is disposed on one side of the waveguide, and light is coupled in through the entrance side of the waveguide. The waveguide uses total internal reflection to guide light through the waveguide. Light follows this waveguide and is decoupled from the exit surface. This surface is the main surface of the waveguide and faces the side where the light is to be emitted. By incorporating an appropriate polarization selection device, light is selectively coupled out of polarization. Such linearly polarized light sources are known. See US 5,729,3 11, US 5,84 5,03 5, WO 01/5 3 745 and WO 01/90637. In addition, in the European patent 86168 -18- 200419220 Lishen case 〇012〇3674 · 5 (applicant reference number PHNL010690EPP) and 01203 666.1 (applicant reference number PHNL〇〇〇683Epp) to explain particularly suitable < specific Instance. These documents also provide suitable methods to allow the waveguide to radiate to one side. One of the methods is to provide a waveguide with a relief structure to the surface or a groove-type coupling element. When the circularly polarized light is incident, the reflective surface (14) is adapted to reverse its rotation. As is well known in the art, specularly reflective metal surfaces provide this inversion. Ming is a low cost traditional choice, but aluminum has a relatively high light absorption, so it is better to use a silver or silver alloy layer with a lower light absorption surface. In view of efficiency and brightness, the higher the specular reflectance, the better. However, for comfortable viewing in the viewing angle range, it is best to have a certain degree of diffuse reflectance, such as ten percent or less. Although the components in FIG. 1 are drawn at intervals, they are not important. The components may be stacked together to form a unified stack. And the components can be properly integrated to save space. In the display described in FIG. 1, a back-illuminated system including a transparent side-illuminated circular polarization can be used instead of the back-illuminated system. Transparency means a special light for incident on the main surface of the waveguide. Transparent, incident light such as that reflected by transflective reflectors and reflective surfaces. The side-illuminated linearly polarized light-emitting waveguide can be composed of a combination of a transparent waveguide substrate and a sterol layer. The inclination of the sterol layer is selected so that visible waveguide light is selectively reflected at the interface between the waveguide substrate and the sterol layer, thereby obtaining the first The reflected beam of the circularly polarized circularly polarized light and the transmitted beam of the second circularly polarized circularly polarized light supplementing the first beam. As everyone skilled in the art knows, according to a specific back-illuminated design, especially 86168 -19- 200419220 how the refractive indices of the sterol layer and the waveguide substrate match, the beam with the first rotation or the beam with the second rotation Can be coupled out in a selective manner. The sterol layer disclosed in EP 606 940 can be adapted to obtain the sterol layer used for back-lighting, but the inclination must be selected so that the sterol layer is most preferably at a waveguide angle rather than the normal angle as in EP 606 940 to be selective Ground reflection is incident on circularly polarized visible light. The inclination is selected using a well-known relation formula = np C0s $, where "n„ is the average refractive index of the sterol material, ', PΠ is the inclination and "< 9, is the incident angle measured from a normal angle The inclination encountered by the incident light at an abnormal angle is greater than that encountered by the incident light at normal angle. Therefore, if visible light is selectively reflected at an abnormal incident angle, especially at a waveguide angle, the inclination needs to be reduced. It is advantageous to reduce the inclination The consequence is that the reflection wavelength is shifted into or into the ultraviolet range at the normal incidence, making the side-illuminated ring-polarized light-emitting waveguide more transmissive in the visible range. As a result of the reflection, the wrong rotation of the liquid crystal cell is prevalent. Light is suppressed. In order to make the side-illuminated ring-polarized light-emitting waveguide more transparent to light incident at normal or near normal angles, the waveguide substrate can be configured with decoupling elements according to the ideal pattern. These decoupling elements are It is well-known and is composed of sterol-based materials. The area that is not covered by the coupling-out element is normal or near-normal incident light, and g is translucent. Effective reflection is obtained at the interface of the substrate. The minimum thickness or height of the sterol layer or element is equivalent to four times the inclination of the sterol material that constitutes the sterol layer or element. The standard thickness is about one to ten microns. 1 A schematic cross-sectional view of a specific example of the transflective display of the present invention, 86168 -20- 200419220; Fig. 2 schematically shows the light emitted by the back-illuminated system when passing through the transflective display in the on state in FIG. 1 Fig. 3 schematically shows the ray trajectory of the light emitted by the back-illuminated system when it is transmitted through the transflective display in the off state in Fig. 1; Fig. 4 schematically shows the transmission of ambient light through the on state in Fig. 1 The trace of the surrounding light when the reflective type indicator is propagating; and FIG. 5 schematically shows the trace of the surrounding light passing through the transflective display in the off state of FIG. 1. [Description of Representative Symbols] 1 Transflective wiper display 2 Transparent Reflective light valve 4 Transflector 6 Back-illuminated system 8 First quarter wave retarder 1 〇 Waveguide 11 lamp 12 Second quarter wave retarder 14 Reflective surface 1 Polarizer 18 quarter Wave blocker 20 LCD cell 31 Light 33 Transmitted light 86168 -21-Reflected light Ray. Surrounded unpolarized light Reflected light Right-handed polarized light Reflected light Peripheral light Left-handed polarized light Right-handed polarized light -22-