{
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  "endpoint": "timeline",
  "stock_code": "6762",
  "company_name": "TDK",
  "content_lang": "ja",
  "meta_lang": "en",
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  "updated": "2026-09-05",
  "license": "© 2026 Yutaka Sugiura. All rights reserved.",
  "attribution": "The社史 (the-shashi.com) — https://the-shashi.com/tse/6762/",
  "source": {
    "primary": [
      "有価証券報告書"
    ],
    "extraction": "有価証券報告書の沿革を基礎に、社史・報道で補完",
    "row_field": "source"
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  "timeline": [
    {
      "date": "1930",
      "importance": 1,
      "event": "世界初の酸化物磁性体「フェライト」の発明",
      "source": null
    },
    {
      "date": "1935/12",
      "importance": 3,
      "event": "フェライト工業化の決断",
      "source": null,
      "link": "/tse/6762/decisions/founding-1935/"
    },
    {
      "date": "1937",
      "importance": 1,
      "event": "フェライトコアの製品化に世界で初めて成功",
      "source": null
    },
    {
      "date": "1937/7",
      "importance": 1,
      "event": "蒲田工場を新設",
      "source": "有価証券報告書"
    },
    {
      "date": "1946",
      "importance": 1,
      "event": "GHQがスーパーヘテロダイン令を交付",
      "source": null
    },
    {
      "date": "1951",
      "importance": 1,
      "event": "セラミックコンデンサーの生産開始",
      "source": null
    },
    {
      "date": "1952/10",
      "importance": 2,
      "event": "清水工場を新設・磁気テープ生産開始",
      "source": "有価証券報告書"
    },
    {
      "date": "1953/10",
      "importance": 1,
      "event": "磁気テープ製品第1号を発売",
      "source": null
    },
    {
      "date": "1957",
      "importance": 1,
      "event": "NHKの放送用テープとして認定",
      "source": null
    },
    {
      "date": "1961/6",
      "importance": 1,
      "event": "事業部制組織形態を採用",
      "source": "有価証券報告書"
    },
    {
      "date": "1961/9",
      "importance": 1,
      "event": "東京証券取引所に株式上場",
      "source": null
    },
    {
      "date": "1966",
      "importance": 3,
      "event": "フィリップスと特許契約を結び国産第1号カセットテープの生産を開始",
      "source": null,
      "link": "/tse/6762/decisions/cassette-tape-1966/"
    },
    {
      "date": "1968/9",
      "importance": 1,
      "event": "世界初の音楽用カセットテープ「SDカセット」を発表",
      "source": null
    },
    {
      "date": "1969/12",
      "importance": 1,
      "event": "千曲川工場を竣工・磁気テープ量産",
      "source": "有価証券報告書"
    },
    {
      "date": "1974/7",
      "importance": 1,
      "event": "米国預託証券（ADR）を発行",
      "source": null
    },
    {
      "date": "1977/4",
      "importance": 1,
      "event": "VHS用ビデオテープの大増産",
      "source": null
    },
    {
      "date": "1978/10",
      "importance": 1,
      "event": "成田工場を竣工・希土類磁石生産",
      "source": "有価証券報告書"
    },
    {
      "date": "1979/11",
      "importance": 1,
      "event": "売上高営業利益率20.1%を記録",
      "source": null
    },
    {
      "date": "1982",
      "importance": 1,
      "event": "磁気テープで世界シェア31.5%、首位を獲得",
      "source": null
    },
    {
      "date": "1982/6",
      "importance": 3,
      "event": "ニューヨーク証券取引所に上場",
      "source": null,
      "link": "/tse/6762/decisions/global-electronics-pivot-1982/"
    },
    {
      "date": "1983/3",
      "importance": 1,
      "event": "社名を「ティーディーケイ」に変更",
      "source": null
    },
    {
      "date": "1985/1",
      "importance": 1,
      "event": "国内初の「完全無担保普通社債」を発行",
      "source": null
    },
    {
      "date": "1986/8",
      "importance": 2,
      "event": "SAE Magneticsを買収、HDD用ヘッド事業に参入",
      "source": null
    },
    {
      "date": "1997",
      "importance": 1,
      "event": "黒字子会社を売却",
      "source": null
    },
    {
      "date": "1997",
      "importance": 2,
      "event": "磁気ヘッドに集中投資",
      "source": null
    },
    {
      "date": "2002/3",
      "importance": 1,
      "event": "上場来初の営業赤字に転落",
      "source": null
    },
    {
      "date": "2005/5",
      "importance": 2,
      "event": "リチウムイオン電池メーカーATLを買収",
      "source": null
    },
    {
      "date": "2005/10",
      "importance": 1,
      "event": "Invensysから電源事業ラムダパワーを買収",
      "source": "有価証券報告書"
    },
    {
      "date": "2007/8",
      "importance": 2,
      "event": "TDKブランド記録メディア事業の売却と磁気テープ生産撤退",
      "source": null
    },
    {
      "date": "2008/10",
      "importance": 3,
      "event": "電子部品メーカーEPCOSを買収",
      "source": null,
      "link": "/tse/6762/decisions/epcos-acquisition-2008/"
    },
    {
      "date": "2013/8",
      "importance": 1,
      "event": "磁気テープ事業からの撤退を発表",
      "source": null
    },
    {
      "date": "2017/2",
      "importance": 2,
      "event": "Qualcommと合弁RF360で高周波部品移管",
      "source": "有価証券報告書"
    },
    {
      "date": "2017/5",
      "importance": 2,
      "event": "InvenSenseを約1,427億円で買収",
      "source": null
    },
    {
      "date": "2023/3",
      "importance": 1,
      "event": "連結売上高2兆円を突破",
      "source": null
    },
    {
      "date": "2025/3",
      "importance": 1,
      "event": "創業90周年、売上高2兆2,048億円",
      "source": null
    }
  ]
}