Observation device
AssigneeCanon Kabushiki Kaisha
InventorKen Wada
Life of this patent
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Abstract
In an observation device including a display device, paired ocular optical systems each include a resin lens having a shape defined by an arch and a chord, and provided with a molding gate in an outer peripheral portion of the arc shape, and is appropriately set in: a difference RC between the radius of the resin lens and the length of a line connecting the midpoint of the chord and the point on the optical axis; the diameter D of the resin lens; an angle θ between a direction connecting a midpoint of a long side of the display surface and the point on the optical axis and a direction connecting the molding gate and the point on the optical axis; and an acute angle α between directions connecting the point on the optical axis and the respective molding gates of the resin lenses in the paired ocular optical systems.
Claims5
An observation device comprising:
- a display element having a rectangular display surface;
- and
- a pair of ocular optical systems for use to observe an image displayed on the display surface, wherein
- each of the paired ocular optical systems includes a resin lens having a shape defined by an arc and a chord on a cross section perpendicular to an optical axis,
- the resin lens is provided with a molding gate in a portion of an outer periphery of the shape defined by the arc, and
- the following conditional expressions are satisfied:
- 0.08<Rc/D<0.30
- −35°≤θ≤35°
- 0°≤|α|<40°,
- where, on the cross section, Rc is a difference between a radius of a circle formed by extending the arc and a distance from a midpoint of the chord to the optical axis, D is a diameter of the circle, θ is an angle between a direction from the optical axis to a midpoint of a long side of the display surface and a direction from the optical axis to the molding gate and α is an angle between a direction from the optical axis to the molding gate of the resin lens included in one of the paired ocular optical systems and a direction from the molding gate of the resin lens included in the other ocular optical system to the optical axis.
Dependencies are inferred from the claim text.