Display device having an electron gun with pre-focusing lens portion
AssigneeLG. Philips Displays
InventorHeidrun Steinhauser
Life of this patent
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Abstract
This invention relates to a display device comprising a cathode ray tube (1), the cathode ray tube having an electron gun (7) comprising a pre-focusing lens portion, for generating a pre-focusing lens field (22), and a main lens portion, for generating a main lens field (23). The electron gun (7) further comprises an additional grid (10), being positioned in proximity with said main lens portion, whereby a potent Vgx is arranged to be applied to said additional grid (10), for generating, together with one of the potentials Vfoc or Vdyn, an additional lens field in proximity with said main lens field, whereby, in operation, the main lens field and the additional lens field is arranged to cooperate to form an effective main lens field.
Claims9
A display device comprising a cathode ray tube, the cathode ray tube having an electron gun comprising:
- a pre-focusing lens portion, for generating a pre-focusing lens field, and
- a main lens portion, for generating a main lens field,
- characterized in that the electron gun further comprises an additional grid being positioned in proximity with said main lens portion, whereby a potential Vgx is arranged to be applied to said additional grid, for generating, together with one of the potentials Vfoc or Vdyn, an additional lens field in proximity with said main lens field, whereby, in operation, the main lens field and the additional lens field is arranged to cooperate to form an effective main lens field.
A cathode ray tube device for use in a display device, the cathode ray tube having an electron gun comprising:
- a pre-focusing lens portion, for generating a pre-focusing lens field, and
- a main lens portion, for generating a main lens field.
- characterized in that the electron gun further comprises an additional grid being positioned in proximity with said main lens portion, whereby a potential Vgx is arranged to be applied to said additional grid, for generating, together with one of the potentials Vfoc or Vdyn, an additional lens field in proximity with said main lens field, whereby, in operation, the main lens field and the additional lens field is arranged to cooperate to form an effective main lens field.
An electron gun comprising:
- a pre-focusing, lens portion, for generating a pre-focusing lens field, and
- a main lens portion, for generating a main lens field,
- characterized in that the electron gun further comprises an additional grid being positioned in proximity with said main lens portion, whereby a potential Vgx is arranged to be applied to said additional grid, for generating, together with one of the potentials Vfoc or Vdyn, an additional lens field in proximity with said main lens field, whereby, in operation, the main lens field and the additional lens field is arranged to cooperate to form an effective main lens field.
Dependencies are inferred from the claim text.