METHOD AND APPARATUS FOR MANUFACTURING A COLOR CRT

IN ACCORDANCE WITH THE PRESENT INVENTION, A METHOD FOR MANUFACTURING A COLOR CRT (10) HAVING A FACEPLATE PANEL (12) IS DISCLOSED. THE METHOD INCLUDES THE STEPS OF FORMING A PHOTORECEPTOR (36) ON AN INTERIOR SURFACE OF A VIEWING FACEPLATE (17); ESTABLISHING A SUBSTANTIALLY UNIFORM ELECTROSTATIC CHARGE ON THE PHOTORECEPTOR (36); AND EXPOSING SELECTED AREAS OF THE PHOTORECEPTOR (36) TO VISIBLE LIGHT TO FORM A LATENT CHARGE IMAGE. THE PROCESS FURTHER INCLUDES THE STEPS OF DEVELOPING THE LATENT CHARGE IMAGE ON THE PHOTORECEPTOR (36) BY DEPOSITING (212, 213, 214) THEREON CHARGED PHOSPHOR PARTICLES; MONITORING THE WIDTH (218) OF THE DEPOSITION OF THE CHARGED PHOSPHOR PARTICLES; AND TERMINATING THE DEPOSITION (226, 227, 228) OF THE CHARGED PHOSPHOR PARTICLES WHEN PREDETERMINED PROCESS PARAMETERS (222, 224) ARE SATISFIED. A PHOSPHOR DEPOSITION MONITOR (PDM) APPARATUS (90) FOR MONITORING THE DEPOSITION OF THE CHARGED PHOSPHOR PARTICLES ON THE LATENT CHARGE IMAGE, FORMED ON THE PHOTORECEPTOR (36), ALSO IS DESCRIBED. THE PDM APPARATUS (90) INCLUDES MONITORING MEANS (96, 99, 123) EXTERNAL TO THE VIEWING FACEPLATE (17) FOR MEASURING THE WIDTH (218) OF THE DEPOSITION OF THE CHARGED PHOSPHOR PARTICLES. CONTROL MEANS (122) RESPONSIVE TO THE MONITORING MEANS (96, 99,123) IS UTILIZED FOR TERMINATING THE DEPOSITION (226, 228) OF THE CHARGED PHOSPHOR PARTICLES WHEN THE PREDETERMINED PROCESS PARAMETERS (222, 224) ARE SATISFIED.