php - json_encode は、ネストされた JSON の二重引用符を作成します

Question

を使用して出力する次の配列がありますecho json_encode(array);

Array (
  [0] => Array (
  [id] => 85
  [name] => yeyery
  [area_xy] => {"type": "rectangle","coordinates": {"point1":"22.272219163607744:114.13580417633057","point2":"22.275753627993897:114.1413402557373","point3":"22.27297371968214:114.14400100708008","point4":"22.270868895211578:114.13910865783691"}}
  )
)

そして、これは私が得る出力です:

[
   {
      "id":"85",
      "name":"yeyery",
      "area_xy":"{\"type\": \"rectangle\",\"coordinates\": {\"point1\":\"22.272219163607744:114.13580417633057\",\"point2\":\"22.275753627993897:114.1413402557373\",\"point3\":\"22.27297371968214:114.14400100708008\",\"point4\":\"22.270868895211578:114.13910865783691\"}}",
   }
]

しかし、意図した出力は次のとおりです。

[
   {
      "id":"85",
      "name":"yeyery",
      "area_xy":{"type": "rectangle","coordinates": {"point1":"22.272219163607744:114.13580417633057","point2":"22.275753627993897:114.1413402557373","point3":"22.27297371968214:114.14400100708008","point4":"22.270868895211578:114.13910865783691"}},
   }
]

入れ子になった JSON を二"area_xy"重引用符で囲みたくありません。