Abstract: In present day color display tubes (1) the microphony performance of the shadow mask (13) is becoming increasingly important, especially in color display tubes (1) with a flat or nearly flat outer side of the display window (3). This invention discloses a mask frame (14) which by means of the transfer of vibrations from the outside of the color display tube (1) to the shadow mask (13) is hampered. This makes the shadow mask (13) less sensitive to vibrations, leading to an improved performance with respect to color purity. This object is achieved by providing the diaphragm parts (15), which form a part of the mask frame (14), with indents (27). Preferably, the skirt (19) of the shadow mask (13) is connected to the diaphragm part 15 by providing one spot weld (28) in between each pair of adjacent indents (27).

Abstract: In color display tubes (1) the color purity performance is of the utmost importance. One of the factors adversely affecting this color purity performance is the microphony behavior of the shadow mask (13). Vibrations or shocks coming from outside the color display tube (1) can be transferred to the shadow mask (13) via the suspension means (20) of the color selection electrode (12). By introducing a vibration damping element (40, 45) coupled to the resilient element (30) of the suspension means (20), the amount of spot shift on the screen (6) due to these vibrations is reduced by at least 50%. The vibration damping element (40, 45) is preferably a flat plate which is rigidly coupled with one side to the suspension means (20), while the other side is in close contact with the resilient element (30), as a result of which it is capable of absorbing said vibrations.

Abstract: In color display tubes (1) the color purity performance is of the utmost importance. One of the factors adversely affecting this color purity performance is the microphony behavior of the shadow mask (13). Vibrations or shocks coming from outside the color display tube (1) can be transferred to the shadow mask (13) via the suspension means (20) of the color selection electrode (12). By introducing a vibration damping element (40, 45) coupled to the resilient element (30) of the suspension means (20), the amount of spot shift on the screen (6) due to these vibrations is reduced by at least 50%. The vibration damping element (40, 45) is preferably a flat plate which is rigidly coupled with one side to the suspension means (20), while the other side is in close contact with the resilient element (30), as a result of which it is capable of absorbing said vibrations.