Abstract: A zoom lens includes, in order from an enlargement side to a reduction side, a first lens unit having positive refractive power and not moving for zooming, a second lens unit having negative refractive power and moving for zooming, a stop, a zooming lens unit having positive refractive power and moving for zooming, and a final lens unit having positive refractive power and not moving for zooming. During zooming from a wide-angle end to a telephoto end, the second lens unit moves to the reduction side and the zooming lens unit moves to the enlargement side. The zooming lens unit includes a cemented lens. The cemented lens includes a negative lens and a positive lens cemented in order from the enlargement side. A cemented surface of the cemented lens has a convex shape on the enlargement side. The zoom lens satisfies predetermined conditions.

Abstract: Horizontal support bodies supporting a color selection electrode in horizontal direction are supported by vertical support bodies extending in vertical direction. The vertical support bodies have positioning holes, respectively, and the positioning holes are disposed in horizontal direction. Positioning pins are engaged in the positioning holes, respectively. The positioning pins move in horizontal direction so that the support frame structure is positioned in horizontal direction and vertical direction.

Abstract: A color selection mask is provided with an aperture region including a slit region (21) and bridge regions (22). The bridge regions (22) are provided on top and bottom ends of the aperture region. In the slit region (21), slits (123) through which electron beams pass and strips (124) are arranged alternately. The strips (124) extend into the bridge regions (22), where bridges (25) for connecting adjacent two of the strips (124) and through holes (122) through which electron beams pass are provided.

Abstract: A tensioned mask structure for a color CRT includes a color-selecting mask that is formed with a plurality of electron beam passing holes therein, a mask frame on which the color-selecting mask is mounted, and a vibration-attenuating mechanism in contact with the color-selecting mask to damp vibration of the color-selecting mask. The color-selecting mask includes an effective mask area having a slit region and a slot region. The slit region has a plurality of long narrow elements that extend in a vertical direction of a screen of the CRT and are aligned to define slit-like holes between adjacent long narrow elements. The slot region has a plurality of slot-like holes shorter than the slit-like holes, the slot-like holes extending in the vertical direction. The slit region is formed in an area except a left peripheral portion and a right peripheral portion of the effective mask area.