Video camera unit having an airtight mounting arrangement for an image sensor chip

A solid-state image pickup device comprising:

• a base;
• a solid-state image sensor mounted on said base;
• a cylindrical holder having an inner wall, a front end and a back end, said back end being coupled to said base;
• a plurality of plastic lenses housed in said cylindrical holder, each of said lenses having a central portion for focusing light and also being provided at its peripheral edge with a rib in contact with the inner wall of said cylindrical holder, wherein, for each of said lenses, the thickness of its rib is greater than the thickness of at least a part of said central portion of the lens, and wherein a surface of each of said ribs which contacts said inner wall of said cylindrical holder is tapered for facilitating insertion of said lenses into said holder for said housing of said lenses;
• a lens holding cover provided at said front end of said cylindrical holder for fixing said plurality of plastic lenses;
• and
• light shielding plates provided between adjacent ones of said plurality of plastic lenses,
• wherein said light shielding plates are located between ribs of adjacent lenses, and wherein the thicknesses of said ribs and the thicknesses of said light shielding plates serve to define distances between the central portions of said lenses.

An airtight sealed video camera unit using a bare solid-state image sensor chip comprising:

• a plastic lens unit;
• a cylindrical holder in which said plastic lens unit is housed, said cylindrical holder having a front end and a back end;
• a one-piece cylindrical base member including a circular plate having a peripheral edge, and including a cylindrical upright member extending to a predetermined height from the peripheral edge of said circular plate to be integral therewith, said back end of said cylindrical holder being received by said cylindrical base member;
• a bare solid-state image sensor chip mounted on said plate for receiving light having passed through said plastic lens unit, said height of said cylindrical upright member being such that at least part of said cylindrical upright member adjustably surrounds said back end of said cylindrical holder for focusing adjustment between said plastic lens unit and said bare solid-state image sensor on said circular plate when said back end of said cylindrical holder is received by said cylindrical base member;
• a cylindrical case having front and back end openings opposed to each other and surrounding said cylindrical holder and said cylindrical upright member of said cylindrical base member, said cylindrical upright member of said cylindrical base member being coupled to said cylindrical case in an airtight structure;
• and
• a transparent cap mounted on said cylindrical case in an airtight structure to cover said front end opening of said cylindrical case and to be spaced apart from said plastic lens unit, said back end opening of said cylindrical case being covered with said circular plate of said cylindrical base member, and said lens unit in said cylindrical holder receiving light coming from through said transparent cap;
• wherein said cylindrical case, said cylindrical base member and said transparent cap cooperate with one another to provide a airtight sealed structure for said plastic lens unit and said solid-state image sensor chip.