200840247 九、發明說明 【發明所屬之技術領域】 本發明係關於一種使用照明光來進行通訊的技術。 【先前技術】 近年來，正在實際運用以LED (Light Emitting Diode )等之半導體發光元件來做爲光源的照明，連利用這些照 明光來傳送資訊的技術，也在如專利文獻1等中被提出硏 究。爲了用於照明使用，就必須具備某種強度的光，藉由 這種強光即可傳送資訊。爲了得到這種強光，可在照明裝 置設置多數的半導體發光元件，並使其發光。 但是，因爲照明光是只有從照明裝置放射出來而已， 所以僅能夠進行單向通訊。以往爲了可以進行雙向通訊， 則在照明器具上設置受光元件。例如在專利文獻2中，除 了照明用的半導體發光元件外，又設置了可視光或紅外線 的受光元件。 另一方面，雖然發光元件的單一 LED亦可做爲受光 元件來使用，例如在非專利文獻1等中已爲眾所皆知。但 是，LED的受光特性，比起目前廣被使用於受光元件的光 電二極體爲差。所以，只能在具有透鏡等之用來集光的光 學系，在接收傳收固定的狀態下，才能來進行通訊。 此外，爲了讓發光元件可直接做爲受光元件來使用， 必須使其在不發光的狀態下來進行受光。但是，在使用發 光元件來做爲照明時，不使該發光元件發光，則又產生了 -5- 200840247 失去其做爲照明功能的問題。 [專利文獻1]日本發明第3 827082號公報 [專利文獻2]日本特開2004-221747號公報 [非專利文獻1]岡本硏正、「使用超高亮度發光二極 體來做爲發光兼受光元件之新的光裝置」、電子資訊通訊 學會、信學技報OQE90-7、1990 【發明內容】 [發明所欲解決之課題] 本發明鑑於上述情事，其目的即爲提供一種雙向照明 光通訊裝置，其係可直接將進行照明的半導體發光元件使 用於受光，不須要用來受光的元件。 [用以解決課題之手段] 本發明之雙方照明光通訊裝置，其特徵爲具備··由發 出照明光之複數個半導體發光元件所構成之發光手段；和 把必須傳送之資料予以調變，使上述發光手段閃爍或改變 其光量的調變手段；和收訊手段，該收訊手段係接收，在 上述發光手段沒有發光之狀態下受光時所得到之訊號爲基 礎而被發送過來的資料；和切換手段，該切換手段係切換 著，利用上述發光手段之發光所進行的資料之傳送、與不 使上述發光手段發光所進行之資料的接收；以及時序訊號 產生手段，該時序訊號產生手段係產生一種針對上述切換 手段，以分時方式來切換資料之傳送接收所需的切換訊號 -6 - 200840247 發光手段的可構成爲：將複數個半導體發光元件予以 並聯；或者是將複數個上述半導體發光元件中的數個設爲 一個群組，再把群組內的半導體發光元件予以串聯的同時 ，各群組爲並聯。此外，其構成亦可爲：利用時序訊號產 生手段的切換訊號，將複數個上述半導體發光元件的連接 ，切換爲並聯或串聯。 時序訊號產生手段係產生一種切換訊號，該切換訊號 係在資料收訊時，即使上述發光手段沒有亮燈，仍不會發 生明滅的週期中，切換資料的接收與傳送。 [發明效果] 根據本發明，即可將由爲了照明而設置之複數個半導 體發光元件所構成的發光手段，用於資料的傳送與接收， 只要利用發光手段，即可進行資料的傳送接收。此外，雖 然單一的半導體發光元件，在受光時的輸出非常小，但只 要利用爲了照明所設置之複數個半導體發光元件來受光， 即可在資料的收訊時，得到充份的輸出。 甚至，在接收資料時，必須在不使發光手段發光的狀 態下來進行，一旦發光手段燈滅就無法進照明。在本發明 中，可藉由快速地切換收送訊，使目視如同連續燈亮般， 可一邊進行照明，一邊進行資料的傳送接收。 【實施方式】 200840247 第1圖係本發明之一實施形態的方塊圖。在圖中，1 爲照明裝置，1 1爲調變部，12爲切換部’ 1 3爲發光元件 群，1 4爲收訊部，1 5爲時序產生部，2爲通訊終端裝置， 21爲受光部，22爲收訊部，23爲同期部’ 24爲調變部， 25爲發光部。 照明裝置1係由：用來發光並執行照明的發光元件群 1 3、調變部1 1、切換部1 2、收訊部1 4、以及時序產生部 1 5所構成。 調變部1 1係將藉由照明光所傳送之送訊資料予以調 變。有關調變方式，不論在傳送任何送訊資料的情況下， 只要可儘量使發光元件群1 3所放射之光量均一的方式即 可。 切換部1 2係爲切換收訊與送訊者，在送訊時，係將 在調變部1 1所調變的送訊資料送到發光元件群1 3，在收 訊時則是將由發光元件群1 3所受光的訊號，傳送到收訊 部1 4。用來切換收訊送訊的切換訊號，係來自時序產生部 15 〇 發光元件群13係由多數的LED或LD (Laser Diode )等的半導體發光元件所構成。在本實施形態中，各半導 體發光元件係爲並聯。在送訊時’根據由調變部1 1所調 變的送訊資料來閃爍或改變其光量而發光，全體均可做爲 照明光來使用。此外，在收訊時’用來發光的訊號會不見 ，而將受光的訊號傳送到收訊部1 4。此時，因爲各半導體 發光元件係爲並聯，所以在某程度的範圍內，只要有訊號 -8 - 200840247 光（在通訊終端裝置2所發出的訊號光）照射的話，複數 個半導體發光元件都可受光，使受光訊號變大。再者，在 串聯的情況下，雖然所有的半導體發光元件若沒有照射到 訊號光即無法收訊，但是只要爲並聯的話，則只要一部份 的半導體元件有照射到訊號光，即可收訊。 做爲構成發光元件群13之各半導體發光元件來使用 的LED，爲了可發出照明光，最好使用可發出白色光或近 於白色光者爲宜。但是，LED本身則是具有愈接近波長較 長之紅色，其收訊感度愈高的特性。所以，使用發出 RGB3波長之光的元件，使其得到3波長中之紅色光的受 光訊號，係優於將藍色的發光照射到螢光體，以得到白色 光的光源。甚至，還可藉由使用反射型LED等，使受光 面積變大。 收訊部1 4係將由發光元件群1 3所受光之訊號予以調 變，並將收訊資料予以輸出。 時序產生部1 5係產生用來利用時分割以切換收送訊 的切換訊號。此時，因爲係以由發光元件群1 3所放射出 來的光做爲照明爲前提，所以在收訊時，就必須避免因爲 燈滅所造成的照明阻礙，或讓人有閃爍的感覺。因此，用 來切換的週期，最好是以數kHz以上來進行爲宜。當然， 點燈與熄燈的時間不須相同，在照明時，讓點燈時間較長 爲宜。相反地，在照明燈滅時，則可使收訊時間變長，或 是使沒有送訊的時間做爲收訊狀態。 通訊終端裝置2，係具有在接收了由照明裝置1之照 -9 - 200840247 明光所傳送來之資料的同時，又藉由光來傳送資料的功能 。因此，通訊終端裝置2的構成係包含：受光部21、收訊 部22、同期部23、調變部24，以及發光部25等。 受光部2 1係接收照明光，並將之轉換爲電性訊號。 例如：可爲將光電二極體等的光轉換爲電性訊號的元件所 構成。收訊部2 2係將從受光部2 1所輸出的訊號予以解調 ，接收原來的資料。此外，也將來自受光部2 1的訊號傳 送到同期部2 3，並且在接受資料時，係根據來自同期部 23的同期訊號來執行。 同期部23係以來自收訊部22的訊號爲基準，檢測照 明裝置1的送訊時機，並將該檢測結果傳送到收訊部2 2 以及調變部24。特別是，因爲照明裝置丨係如上述般，切 換著送訊以及收訊，所以，只要照明裝置1進到收訊相， 就會注意到照明光消失，即可取得同期。 調變部24係根據來自同期部23的同期訊號，將必須 送到照明裝置1的資料予以調變，再傳送到發光部25。發 光部25係將來自調變部24之已被調變的資料轉換爲光來 傳送。發光部25係可使用如LED等之發光元件。所發之 光的波長，儘可能是在照明裝置1之發光元件群1 3中， 可有效受光者爲佳，例如：在使用RGB之發光元件來做 爲半導體發光元件1 3時，以使用近於紅色者爲宜。 再者，通訊終端裝置2也可同於照明裝置1，其受光 部2 1以及發光部25係可由發光元件所構成。 接下來，針對本發明之一實施形態的動作來加以說明 -10- 200840247 。在以下的說明中，係針對以藉由發光元件群1 3所發出 之光來做爲照明者來加以說明。時序產生部1 6，係在因爲 收訊時之發光元件群1 3的燈滅，仍無損其做爲照明功能 的週期中，產生並輸出切換收訊以及送訊的切換訊號。 利用時序產生部1 6之切換訊號，藉由照明光來傳送 送訊資料時，調變部1 1會將送訊資料予以調變，而切換 部1 2則將已被調變的送訊資料傳送到發光元件群1 3。如 此一來，發光元件群13的各半導體發光元件，就可依已 被調變的送訊資料來閃爍或改變其光量，以進行送訊資料 之傳送。此時的閃爍或光量變動，係以極高速來進行，所 以人眼是不太容易發覺。此外，若在不使照明光之光量變 動的情況下，先進行送訊資料之調變的話，則發光元件群 1 3所發出的光，就可做爲幾乎一樣的照明光來使用。 由發光元件群1 3所發出的照明光，只要在通訊終端 裝置2的受光部21受光，在解調部2 2被解調的話，即可 接收送訊資料。再者，在通訊終端裝置2，同期部23係從 接收之照明光所得到之訊號，檢測出照明裝置1之收訊送 訊的切換時序，根據檢測出來的時序訊號，來進行資料的 傳送與接收。 另一方面，在通訊終端裝置2將資料傳送到照明裝置 1時，藉由接收照明光，即可根據在同期部23所檢測出之 照明裝置1之收送訊的切換時序，當照明裝置1處於收訊 狀態時’可根據由調變部24所調變的資料，驅動發光部 25，並利用光來傳送資料。 -11 - 200840247 在照明裝置1，當接收資料時，切換部1 2係根據時序 產生部16的切換訊號，將來自發光元件群13的訊號，切 換成傳送到收訊部14。被通訊終端裝置2之發光部25所 放出的資料所調變的光，係被發光元件群1 3所接收。此 日寸’來自通訊終端裝置2的光，會有某種程度的擴散，所 以會被並聯的複數個半導體發光元件所接收，並由各個半 導體發光元件轉換成電性訊號。因此，雖然一個半導體發 光元件的受光能力較小，但可利用由複數個半導體發光元 件來受光，即可得到更大的訊號。並且，收訊時的訊號大 小，係隨著半導體發光元件的個數愈多，也變得愈大。 由發光元件群1 3所輸出的訊號，被輸入至收訊部1 4 ’藉由解調即可接收來自通訊終端裝置2的資料。 以下係針對本發明之一實施形態之通訊的具體例來加 以說明。第2圖係資料之接收傳送之一例的說明圖。在此 例中，係使用 PPM (Pulse Position Modulation: 脈衝位 置調變）方式來做爲調變方式，8個時槽構成1個符號， 前半的4個時槽係用於從照明裝置1朝通訊終端裝置2傳 送的通訊用，而後半的4個時槽則是用於從通訊終端裝置 2朝照明裝置1傳送的通訊用。並且，藉由在各4個時槽 中有否設置脈衝，來顯示2位元圖案〇〇、01、1〇、11中 的任一個。 於第2圖所示的實施例中，從照明裝置1朝通訊終端 裝置2傳送時，係將一般所使用的PPM的波形予以反轉 來使用。也就是說，在具有脈衝的位置，波形爲下降。如 -12- 200840247 此一來，只要將0N的時間變長’即可儘量抑制照明光的 光量減少。此外，在ppM中，ΟΝ/OFF的時間不會根據資 料而有太大的改變’故可確保穩定的照明光量。 有關從通訊終端裝置2將資料傳送到照明裝置1，因 爲與照明裝置1相反，係可利用使發光時間變短來抑制消 耗的電力，所以是使用一般所使用的PPM方式，來進行 資料的傳送。 第3圖係通訊終端裝置2之時序檢測方法之一例的說 明圖。如第2圖所示，只要使用PPM方式的反轉波形， 從照明裝置1來傳送資料的話，則後半的4個時槽必定爲 OFF，而前半的4個時槽中，則只有任一個爲OFF。此外 ，如果照明裝置1沒有在傳送資料時，前半的4個時槽則 全部爲ON。 具有這樣的特性，即可在通訊終端裝置2的同期部23 ，檢測出照明裝置1之送訊收訊的切換時序。也就是說， 照明裝置1是否如第3圖（A )所示般，傳送著各種的資 料，或者是沒有傳送資料的話，只要將1訊框（8時槽） 份的收訊訊號加以合成、加算或平均化，就會如第3圖（ B )所示般，前半的4個時槽會變成ON，後半的4個時槽 會變成OFF。只要檢測出這種上揚或下降的範圍，即可在 通訊終端裝置2檢測出照明裝置1的收送訊的切換時序。 通訊終端裝置2只要使用如此檢測出來的切換時序，將資 料的收訊送訊予以切換即可。 再者，爲了檢測出切換時序，就必須將來自照明裝置 -13- 200840247 1的照明光分成複數個訊框份，加以合成、加算或平均化 等’但只要讓該訊框數增多，即可更正確地檢測出時序。 此外’在照明裝置1燈滅時，雖可使用一般的PPM波形 來進行資料的傳送，但在此種情況下，只要照明裝置1有 傳送資料，即可利用同樣的方法來檢測出切換時序，來進 行通訊。 上述的通訊方法係爲一例，有關1個符號的時槽數、 或是1個符號中所分配的時槽數，只要在設計時決定了即 可。例如可採用：設定1個符號爲12時槽，將8個時槽 用於從照明裝置1傳往通訊終端裝置2的通訊，將4個時 槽用於從通訊終端裝置2傳往照明裝置1的通訊。此時， 因爲照明裝置之發光元件群1 3的發光時間變長，所以可 增加照明光量。當然，調變方式不只限於PPM，只要做爲 照明光之光量的變動較少的調變方式即可。 第4圖係顯示本發明之一實施形態之第1變形例的方 塊圖。在第1圖所示的構成例中，發光元件群1 3的各半 導體發光元件係爲並聯。一旦各半導體發光元件爲並聯， 在接收資料時，即可利用來自受到通訊終端裝置2的光所 照射之各半導體發光元件的訊號。但是，在使其發光時， 必須對並聯的各半導體發光元件供應驅動電流才行’所以 驅動電流也會變大。因此，爲了降低發光時的電流，在第 4圖所示的變形例中，即把數個半導體發光元件做爲一群 組並將其串聯，再將這種群組予以並聯。再者，通訊終端 裝置2的構成可同於第1圖所示者。 -14- 200840247 在這種構成中，可提高發光驅動發光元件群13時的 電壓，使電流降低，此與第1圖所示的構成相較的話，可 藉由較小的電流來驅動發光元件群1 3。此外’只要群組內 的半導體發光元件有受到光，即可輸出訊號，所以即使是 只有發光元件群1 3的一部份受光，仍可受光而輸出訊號 〇 第5圖係顯示本發明之一實施形態之第2變形例的方 塊圖。在本第2變形例中，發光元件群13的各半導體發 光元件的連接，在送訊時係爲串聯，而在收訊時則切換爲 並聯。第5圖（A )係顯示切換爲串聯的情形，第5圖（B )係顯示切換爲並聯的情形。此外，雖省略有關通訊終端 裝置2的圖示，其構成可同於第1圖。 當從照明裝置1傳送資料時，因爲要發出照明光，所 以須要較大的電力。因此，就如第5圖（A )所示般，各 半導體發光元件被切換成串聯。如此一來，就能產生較高 的電壓，藉由較小的電流仍可發光驅動。此外，在收訊時 ，爲了可有效利用各半導體發元件受光所輸出的訊號，就 會如第5圖（B)所示般，將各半導體發光元件切換成並 聯。當複數個半導體發光元件爲串聯時，雖然只能輸出由 該串聯之半導體發光元件所輸出之訊號中最弱的訊號，但 若爲並聯的話，則可利用各個半導體發光元件來進行輸出 〇 又，串聯與並聯的切換，係可使用來自時序產生部1 5 的切換訊號，該切換訊號係用於在切換部1 2之收訊送訊 -15- 200840247 的切換。 上述的一實施形態以及其變形例係爲一例’只要是在 沒有脫離本發明之要旨的範圍內，當然仍可有其他各種的 變化。 【圖式簡單說明】 第1圖係本發明之一實施形態的方塊圖° 第2圖係資料之傳送接收之一例的說明圖。 第3圖係通訊終端裝置2之時序檢測方法之一例的說 明圖。 第4圖係顯示本發明之一實施形態之第1變形例的方 塊圖。 第5圖係顯示本發明之一實施形態之第2變形例的方 塊圖。 【主要元件符號說明】 1 :照明裝置 1 1 :調變部 1 2 :切換部 1 3 :發光元件群 1 4 :收訊部 1 5 :時序產生部 2 :通訊終端裝置 21 :受光部 -16- 200840247 2 2 :收訊部 23 :同期部 24 :調變部 2 5 :發光部200840247 IX. Description of the Invention [Technical Field of the Invention] The present invention relates to a technique for communicating using illumination light. [Prior Art] In recent years, a technique in which a semiconductor light-emitting element such as an LED (Light Emitting Diode) is used as a light source, and a technique of transmitting information by using the illumination light is also proposed as in Patent Document 1 and the like. research. In order to be used for lighting, it is necessary to have light of a certain intensity, by which the information can be transmitted. In order to obtain such strong light, a plurality of semiconductor light-emitting elements can be provided in the illumination device and emit light. However, since the illumination light is emitted only from the illumination device, only one-way communication is possible. Conventionally, in order to enable two-way communication, a light receiving element is provided on a lighting fixture. For example, in Patent Document 2, in addition to the semiconductor light-emitting element for illumination, a light-receiving element of visible light or infrared light is provided. On the other hand, a single LED of a light-emitting element can also be used as a light-receiving element, and is known, for example, in Non-Patent Document 1 and the like. However, the light-receiving characteristics of the LED are inferior to those of the photodiode which is currently widely used for the light-receiving element. Therefore, it is only possible to communicate in an optical system for collecting light, such as a lens, in a state where reception and transmission are fixed. Further, in order to allow the light-emitting element to be used as a light-receiving element as it is, it is necessary to receive light in a state where it does not emit light. However, when the illuminating element is used as the illumination, the illuminating element is not caused to emit light, and the problem of losing the illumination function is also generated. [Patent Document 1] Japanese Laid-Open Patent Publication No. 2004-221747 [Non-Patent Document 1] Okamoto Masahiro, "Using Ultra High Brightness Light Emitting Diodes as Light Emitting and Receiving Light [New Optical Device for Components", Electronic Information and Communication Society, Letters and Information Technology OQE90-7, 1990 [Disclosure] The present invention has been made in view of the above circumstances, and its object is to provide a two-way illumination optical communication. A device for directly illuminating a semiconductor light-emitting element for receiving light, which does not need to be used for receiving light. [Means for Solving the Problem] The both-illuminated optical communication device of the present invention is characterized in that it includes a light-emitting means composed of a plurality of semiconductor light-emitting elements that emit illumination light, and a material that must be transmitted is modulated. a means for modulating the amount of light by the illuminating means; and means for receiving the signal, the receiving means receiving the data transmitted based on the signal obtained when the light-emitting means is not illuminated; and a switching means for switching the data transmitted by the light-emitting means and the data received by the light-emitting means not to be received; and the timing signal generating means, the timing signal generating means is generated A switching signal required for transmitting and receiving data in a time-sharing manner for the above switching means -6 - 200840247 illuminating means may be configured to: connect a plurality of semiconductor light-emitting elements in parallel; or a plurality of the above-mentioned semiconductor light-emitting elements The number in the group is set to one group, and then the semiconductor light-emitting elements in the group While being connected in series, each group is connected in parallel. Further, the configuration may be such that the connection of the plurality of semiconductor light-emitting elements is switched to be connected in parallel or in series by using a switching signal of the timing signal generating means. The timing signal generating means generates a switching signal which is used for receiving and transmitting the switching data during the data reception even if the above-mentioned light-emitting means is not lit, and the switching data is not generated during the clearing period. [Effect of the Invention] According to the present invention, a light-emitting means composed of a plurality of semiconductor light-emitting elements provided for illumination can be used for data transmission and reception, and data can be transmitted and received by using a light-emitting means. Further, although a single semiconductor light-emitting element has a very small output at the time of light reception, it is possible to obtain a sufficient output at the time of data reception by receiving light by a plurality of semiconductor light-emitting elements provided for illumination. Even when receiving data, it must be carried out without lighting the illuminating means, and once the illuminating means is turned off, the lighting cannot be performed. In the present invention, by quickly switching the transmission and reception, the viewing can be performed as if the continuous light is on, and the data can be transmitted and received while being illuminated. [Embodiment] 200840247 Fig. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is an illumination device, 1 1 is a modulation unit, 12 is a switching unit '1 3 is a light-emitting element group, 14 is a reception unit, 15 is a timing generation unit, 2 is a communication terminal device, 21 is The light receiving unit 22 is a receiving unit, and 23 is a synchronous unit '24 is a modulation unit, and 25 is a light emitting unit. The illumination device 1 is composed of a light-emitting element group 13 for emitting light and performing illumination, a modulation unit 1 1 , a switching unit 1 2, a reception unit 14 and a timing generation unit 15 . The modulation unit 1 1 modulates the transmission data transmitted by the illumination light. Regarding the modulation method, the amount of light emitted by the light-emitting element group 13 can be made uniform as much as possible, regardless of the transmission of any transmission data. The switching unit 12 is configured to switch between the receiving and the transmitting, and sends the transmitted data modulated by the modulation unit 1 to the light-emitting element group 13 during the transmission, and is illuminated by the receiving unit. The signal received by the component group 13 is transmitted to the receiving unit 14 . The switching signal for switching the reception of the reception is from the timing generation unit 15 〇 The light-emitting element group 13 is composed of a plurality of semiconductor light-emitting elements such as LEDs or LDs (Laser Diodes). In the present embodiment, each of the semiconductor light-emitting elements is connected in parallel. At the time of transmission, the light is flashed or changed according to the transmission data modulated by the modulation unit 1 to emit light, and all of them can be used as illumination light. In addition, the signal used for illumination will not be seen at the time of reception, and the signal received by the light will be transmitted to the receiving unit 14. In this case, since the semiconductor light-emitting elements are connected in parallel, in a certain range, as long as the signal -8 - 200840247 light (signal light emitted from the communication terminal device 2) is irradiated, a plurality of semiconductor light-emitting elements can be used. Receiving light, making the received signal larger. Furthermore, in the case of series connection, although all of the semiconductor light-emitting elements cannot be received without the signal light, as long as they are connected in parallel, as long as a part of the semiconductor elements are irradiated with the signal light, the signal can be received. . As the LED used for each of the semiconductor light-emitting elements constituting the light-emitting element group 13, in order to emit illumination light, it is preferable to use white light or white light. However, the LED itself has a characteristic that the closer the wavelength is, the higher the reception sensitivity is. Therefore, an element that emits light of RGB3 wavelength to obtain a light signal of red light of three wavelengths is superior to a light source that emits blue light to the phosphor to obtain white light. It is even possible to increase the light receiving area by using a reflective LED or the like. The receiving unit 14 adjusts the signal received by the light-emitting element group 13 and outputs the received data. The timing generation unit 15 generates a switching signal for switching the transmission and reception by time division. At this time, since the light emitted from the light-emitting element group 13 is used as the illumination, it is necessary to avoid the illumination hindrance caused by the lamp being extinguished or the flickering feeling. Therefore, it is preferable that the period for switching is preferably several kHz or more. Of course, the time for lighting and turning off the lights does not have to be the same. When lighting, it is better to let the lighting time be longer. Conversely, when the illumination is off, the reception time can be made longer, or the time when no transmission is made can be used as the reception status. The communication terminal device 2 has a function of transmitting data by light, while receiving data transmitted by the illumination device 1 - 200840247. Therefore, the configuration of the communication terminal device 2 includes the light receiving unit 21, the receiving unit 22, the synchronization unit 23, the modulation unit 24, and the light-emitting unit 25. The light receiving unit 2 1 receives the illumination light and converts it into an electrical signal. For example, it can be composed of an element that converts light such as a photodiode into an electrical signal. The receiving unit 2 2 demodulates the signal output from the light receiving unit 2 1 and receives the original data. Further, the signal from the light receiving unit 2 1 is also transmitted to the synchronization unit 23, and when the data is received, it is executed based on the synchronization signal from the synchronization unit 23. The synchronization unit 23 detects the transmission timing of the illumination device 1 based on the signal from the reception unit 22, and transmits the detection result to the reception unit 2 2 and the modulation unit 24. In particular, since the illumination device is switched as described above, the transmission and reception are switched. Therefore, as long as the illumination device 1 enters the reception phase, it is noticed that the illumination light disappears and the synchronization can be obtained. The modulation unit 24 modulates the data that must be sent to the illumination device 1 based on the synchronization signal from the synchronization unit 23, and transmits the data to the light-emitting unit 25. The light-emitting unit 25 converts the modulated data from the modulation unit 24 into light for transmission. As the light-emitting portion 25, a light-emitting element such as an LED can be used. The wavelength of the emitted light is preferably as high as possible in the light-emitting element group 13 of the illumination device 1. For example, when the RGB light-emitting element is used as the semiconductor light-emitting element 13 Suitable for red. Further, the communication terminal device 2 may be the same as the illumination device 1, and the light receiving portion 21 and the light emitting portion 25 may be constituted by light emitting elements. Next, an operation of an embodiment of the present invention will be described. -10- 200840247. In the following description, the light emitted by the light-emitting element group 13 will be described as an illuminator. The timing generation unit 1 6 generates and outputs a switching signal for switching reception and transmission in a period in which the light-emitting element group 13 is turned off when the reception is not performed as a lighting function. When the transmission data is transmitted by the illumination light by the switching signal of the timing generation unit 16 , the modulation unit 1 1 modulates the transmission data, and the switching unit 1 2 transmits the transmission data that has been modulated. It is transmitted to the light-emitting element group 13. As a result, each of the semiconductor light-emitting elements of the light-emitting element group 13 can blink or change the amount of light according to the modulated transmission data to transmit the transmission data. At this time, the flicker or the amount of light changes is performed at an extremely high speed, so that the human eye is less likely to be detected. Further, when the amount of illumination light is not changed, if the transmission data is first modulated, the light emitted from the light-emitting element group 13 can be used as almost the same illumination light. The illumination light emitted from the light-emitting element group 13 is received by the light-receiving unit 21 of the communication terminal device 2, and is demodulated by the demodulation unit 2, so that the transmission data can be received. Further, in the communication terminal device 2, the synchronization unit 23 detects the switching timing of the reception and reception of the illumination device 1 from the signal obtained by the received illumination light, and transmits the data based on the detected timing signal. receive. On the other hand, when the communication terminal device 2 transmits the data to the illumination device 1, by receiving the illumination light, the illumination device 1 can be switched based on the switching timing of the transmission and reception of the illumination device 1 detected by the synchronization unit 23. When in the reception state, the light-emitting unit 25 can be driven based on the data modulated by the modulation unit 24, and the light can be used to transmit the data. -11 - 200840247 In the illumination device 1, when receiving data, the switching unit 12 switches the signal from the light-emitting element group 13 to the receiving unit 14 based on the switching signal of the timing generating unit 16. The light modulated by the data emitted from the light-emitting unit 25 of the communication terminal device 2 is received by the light-emitting element group 13. The light from the communication terminal device 2 is diffused to some extent, so that it is received by a plurality of semiconductor light-emitting elements connected in parallel, and is converted into electrical signals by the respective semiconductor light-emitting elements. Therefore, although the light-receiving ability of a semiconductor light-emitting element is small, a larger signal can be obtained by receiving light from a plurality of semiconductor light-emitting elements. Moreover, the size of the signal at the time of reception is larger as the number of semiconductor light-emitting elements increases. The signal output from the light-emitting element group 13 is input to the receiving unit 14', and the data from the communication terminal device 2 can be received by demodulation. The following is a description of specific examples of communication in an embodiment of the present invention. Fig. 2 is an explanatory diagram showing an example of reception and transmission of data. In this example, PPM (Pulse Position Modulation) is used as the modulation method. Eight time slots form one symbol, and the first half of the four time slots are used for communication from the illumination device 1. The terminal device 2 transmits the communication, and the second half of the time slot is used for communication from the communication terminal device 2 to the illumination device 1. Further, any one of the 2-bit patterns 〇〇, 01, 1〇, and 11 is displayed by setting a pulse in each of the four time slots. In the embodiment shown in Fig. 2, when the illumination device 1 is transferred to the communication terminal device 2, the waveform of the PPM which is generally used is inverted and used. That is to say, at the position with the pulse, the waveform is lowered. For example, -12- 200840247, as long as the time of 0N is lengthened, the amount of illumination light can be reduced as much as possible. In addition, in ppM, the ΟΝ/OFF time does not change much depending on the material', so that a stable amount of illumination light can be ensured. When the data is transmitted from the communication terminal device 2 to the illumination device 1, the power can be suppressed by using the PPM method that is generally used, because the illumination time is shortened, and the data is transmitted. . Fig. 3 is an explanatory diagram showing an example of the timing detecting method of the communication terminal device 2. As shown in Fig. 2, if the inverted waveform of the PPM method is used and data is transmitted from the illumination device 1, the four time slots in the second half must be OFF, and only one of the four time slots in the first half is OFF. In addition, if the lighting device 1 is not transmitting data, the four time slots of the first half are all ON. With such characteristics, the synchronization timing of the transmission and reception of the illumination device 1 can be detected in the synchronization unit 23 of the communication terminal device 2. That is to say, whether the illumination device 1 transmits various materials as shown in FIG. 3(A), or if no data is transmitted, the reception signals of the 1-frame (8-time slot) are synthesized. Addition or averaging will be as shown in Figure 3 (B). The four time slots in the first half will turn ON, and the four time slots in the second half will turn OFF. As long as such a range of upswing or falling is detected, the communication terminal device 2 can detect the switching timing of the transmission and reception of the illumination device 1. The communication terminal device 2 can switch the reception of the data by using the thus detected switching timing. Furthermore, in order to detect the switching timing, it is necessary to divide the illumination light from the illumination device-13-200840247 1 into a plurality of frame components, synthesize, add or average, etc., but as long as the number of frames is increased, The timing is detected more correctly. In addition, when the illumination device 1 is turned off, the data can be transmitted using a general PPM waveform. However, in this case, as long as the illumination device 1 transmits data, the same method can be used to detect the switching timing. To communicate. The above communication method is an example, and the number of time slots for one symbol or the number of time slots allocated for one symbol may be determined at the time of design. For example, it is possible to set one symbol to be a 12-hour slot, eight time slots for communication from the illumination device 1 to the communication terminal device 2, and four time slots for transmitting from the communication terminal device 2 to the illumination device 1 Communication. At this time, since the light-emitting time of the light-emitting element group 13 of the illumination device becomes long, the amount of illumination light can be increased. Of course, the modulation method is not limited to the PPM, and it is only required to be a modulation method in which the amount of illumination light is less changed. Fig. 4 is a block diagram showing a first modification of an embodiment of the present invention. In the configuration example shown in Fig. 1, each of the semiconductor light-emitting elements of the light-emitting element group 13 is connected in parallel. When the semiconductor light-emitting elements are connected in parallel, the signals from the respective semiconductor light-emitting elements irradiated by the light of the communication terminal device 2 can be utilized when receiving the data. However, when it emits light, it is necessary to supply a drive current to each of the parallel semiconductor light-emitting elements, so that the drive current also becomes large. Therefore, in order to reduce the current at the time of light emission, in the modification shown in Fig. 4, a plurality of semiconductor light-emitting elements are grouped as a group and connected in series, and this group is connected in parallel. Furthermore, the configuration of the communication terminal device 2 can be the same as that shown in Fig. 1. In the above configuration, the voltage at the time of light-emitting driving of the light-emitting element group 13 can be increased, and the current can be lowered. This can drive the light-emitting element with a smaller current than the configuration shown in Fig. 1 . Group 1 3. In addition, as long as the semiconductor light-emitting elements in the group receive light, the signals can be output, so that even if only a part of the light-emitting element group 13 receives light, the light can be received and the signal is output. FIG. 5 shows one of the present inventions. A block diagram of a second modification of the embodiment. In the second modification, the connection of the semiconductor light-emitting elements of the light-emitting element group 13 is connected in series at the time of transmission, and is switched in parallel at the time of reception. Fig. 5(A) shows the case of switching to series, and Fig. 5(B) shows the case of switching to parallel. Further, although the illustration of the communication terminal device 2 is omitted, the configuration can be the same as that of Fig. 1. When data is transmitted from the lighting device 1, since it is necessary to emit illumination light, a large amount of electric power is required. Therefore, as shown in Fig. 5(A), the semiconductor light-emitting elements are switched in series. In this way, a higher voltage can be generated, and the light can be driven by a smaller current. Further, at the time of reception, in order to effectively utilize the signals output by the semiconductor elements, the semiconductor light-emitting elements are switched in parallel as shown in Fig. 5(B). When a plurality of semiconductor light-emitting elements are connected in series, although only the weakest signals among the signals outputted by the series-connected semiconductor light-emitting elements can be output, if they are connected in parallel, the semiconductor light-emitting elements can be used for outputting. In the series and parallel switching, the switching signal from the timing generating unit 15 can be used, and the switching signal is used for switching of the receiving transmission -15-200840247 in the switching unit 12. The above-described one embodiment and the modifications thereof are merely examples, and as long as they are within the scope of the gist of the invention, various other changes are possible. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention. FIG. 2 is an explanatory diagram showing an example of transmission and reception of data. Fig. 3 is an explanatory diagram showing an example of the timing detecting method of the communication terminal device 2. Fig. 4 is a block diagram showing a first modification of an embodiment of the present invention. Fig. 5 is a block diagram showing a second modification of the embodiment of the present invention. [Description of main component symbols] 1 : Illumination device 1 1 : Modulation unit 1 2 : Switching unit 1 3 : Light-emitting element group 1 4 : Reception unit 1 5 : Timing generation unit 2 : Communication terminal device 21 : Light-receiving unit - 16 - 200840247 2 2 : Reception unit 23 : Synchronization unit 24 : Modulation unit 2 5 : Light-emitting unit