FILTER UNIT

PROBLEM TO BE SOLVED: To provide a filter unit that is suitable for an imaging device having a an image pick-up element of high resolution.SOLUTION: A filter unit 1 is formed of: an annular filter frame 2; a disc-like filter 3 that is housed in an open part on an inner peripheral side of the annular filter frame 2; an annular elastic member 4 in which an insertion part 41 is fittingly inserted into a circumferential groove 32 formed in a periphery face 31 of the disc-like filter 3; and a pressure ring 5 that presses and anchors a pressure reception part 42 of the annular elastic member 4 against the annular filter frame 2. The disc-like filter 3 is held without coming into contact with toughened annular filter frame 2 or pressure ring 5 to thereby allow occurrence of distortion in an incidence surface 3a of the disc-like filter 3 or emerging surface 3b thereof to be substantially prevented, which in turn can be suitable for an imaging device having an image pick-up element of high resolution.SELECTED DRAWING: Figure 1 【課題】高解像度の撮像素子を有する撮像装置に適したフィルターユニットを提供する。【解決手段】円環状フィルター枠２と、この円環状フィルター枠２の内周側空部に収容される円板状フィルター３と、この円板状フィルター３の周面３１に形成した円周溝３２に嵌入部４１が嵌挿される円環状弾性部材４と、この円環状弾性部材４の押圧受け部４２を円環状フィルター枠２に押圧して固定する押え環５と、から成るフィルターユニット１は、円板状フィルター３が硬質の円環状フィルター枠２や押え環５に接触することなく保持されているので、円板状フィルター３の入射面３ａや出射面３ｂに歪が発生するのを実質的に防止することができ、高解像度の撮像素子を有する撮像装置に適したものとなる。【選択図】図１