Confocal scanning microscope and beamsplitter therefor

A confocal scanning microscope for viewing an object, the confocal scanning microscope comprising:

• an illuminating device for transmitting an illuminating beam along an illuminating beam path;
• optic means for defining an imaging beam path;
• a beamsplitter mounted in said imaging beam path and having a partially reflecting layer for deflecting a component of said illuminating beam toward the object whereby said component is reflected back from the object toward said beamsplitter and passes through said beamsplitter into said imaging beam path with unwanted reflections occurring within said beamsplitter;
• said beamsplitter including two prisms having optical faces and said two prisms each having the geometrical form of an isosceles triangle and conjointly defining said partially reflecting layer;
• said beamsplitter having an external form defined by the optical faces of said prisms with each two mutually adjacent ones of said optical faces conjointly defining an angle unequal to 90.degree. whereby said unwanted reflections are substantially prevented from entering said imaging beam path;
• and,
• a perforated rotatable mask mounted between said beamsplitter and said optic means in said beam path so as to be inclined with respect to said beam path.