FOCUS POSITION LOCK DEVICE FOR PROJECTION TELEVISION

An apparatus and method for locking a focus position of a lens assembly without causing the lens cell to tilt, comprising: a spacer interposed between the lens cell and the focus mount. The spacer is received into a sleeve that is integral with the focus mount. The sleeve projects radially outward from the focus mount such that the spacer can be raised and lowered radially with respect to the focus mount. The spacer has a cylindrical body with a radial flange at one end. Moreover, the spacer has two ridges that extend downward from a lower surface of the flange, each of which is received into a corresponding groove on the sleeve, thus, preventing the spacer from rotating within the sleeve. The spacer also has an upwardly raised rim extending from an upper surface of the flange. The rim is slidably secured into a slot of the focus mount, which prevents lateral movement of the spacer. Further, a bolt is coupled to an opening within the spacer, such that one end of the bolt is disposed and secured within the spacer and the other end of the bolt extends radially outward through the slot of the focus mount. A nut is secured onto the bolt. After focusing the lens cell assembly, the nut is tightened onto the bolt in order to maintain focus of the lens cell assembly. The tightening of the nut brings an upper surface of the flange of the spacer into frictional engagement with an interior surface of the focus mount, which prevents the tilting of the lens cell within the focus mount, thus, maintaining a focus position of the lens assembly.