Appeal No. 95-2231 Application No. 08/114,285 a) introducing CF into said lasing gas or gas mixture 4 and reacting said CF with said oxygen impurity which 4 accumulates in said lasing gas or gas mixture, said CF being 4 introduced in an amount effective to produce one or more compounds which are condensable with refrigeration means; and b) condensing said one or more compounds produced in step a) in a cryogenic trap with refrigeration means and at a temperature sufficient to condense said one or more compounds substantially without condensing said lasing gas or gas mixture therewith, thereby removing said oxygen impurity from said lasing gas or gas mixture, thereby extending the operating life of the excimer laser. The references relied on by the examiner are: Bedwell 5,090,020 Feb. 18, 1992 Reid et al., (Reid) “Excimer Lasers: Current Trends and Future Directions,” SPIE O-E/LASE, pp. 1-8, January 1989, (hereinafter referred to as “Reid”). Claims 16 through 19, 21 through 24, 31 and 32 stand rejected under 35 U.S.C. § 103 as unpatentable over Bedwell in view of Reid. We reverse. The examiner acknowledges that: The difference [sic, differences] between the Bedwell reference and the claims are as follows: it does not teach operating the cooling system while the laser is on and does not discuss deliberate introduction of [oxygen or CF impurity] materials 4 into the system. See Answer at page 3. 3Page: Previous 1 2 3 4 5 6 7 8 NextLast modified: November 3, 2007