Abstract: A viewing angle-controlling liquid crystal panel sequentially includes a first polarizing plate; a first liquid crystal panel; a second polarizing plate; a second liquid crystal panel; and a third polarizing plate, wherein an azimuthal angle ?P1 of the absorption axis of the first polarizing plate, an azimuthal angle ?1 of a director of liquid crystal molecules near the first substrate and an azimuthal angle ?2 of a director of liquid crystal molecules near the second substrate in the first liquid crystal panel, an azimuthal angle ?P2 of the absorption axis of the second polarizing plate, an azimuthal angle ?3 of a director of liquid crystal molecules near the third substrate and an azimuthal angle ?4 of a director of liquid crystal molecules near the fourth substrate in the second liquid crystal panel, and an azimuthal angle ?P3 of the absorption axis of the third polarizing plate satisfy specific formulas.

Abstract: A viewing angle-controlling liquid crystal panel sequentially includes a first polarizing plate; a first liquid crystal panel; a second polarizing plate; a second liquid crystal panel; and a third polarizing plate, wherein an azimuthal angle ?P1 of the absorption axis of the first polarizing plate, an azimuthal angle ?1 of a director of liquid crystal molecules near the first substrate and an azimuthal angle ?2 of a director of liquid crystal molecules near the second substrate in the first liquid crystal panel, an azimuthal angle ?P2 of the absorption axis of the second polarizing plate, an azimuthal angle ?3 of a director of liquid crystal molecules near the third substrate and an azimuthal angle ?4 of a director of liquid crystal molecules near the fourth substrate in the second liquid crystal panel, and an azimuthal angle ?P3 of the absorption axis of the third polarizing plate satisfy specific formulas.

Abstract: In construction of a switching device interposed between a pair of power sources and a load circuit and provided with switch and by-pass units, the switch unit is extractable from its housing and operation of the by-pass circuit is interlocked with position of the switch unit with respect to the housing so that the load circuit should be selectively connected to one of the two power sources. For convenience in maintenance and/or operation of device elements, shift of connection of the load circuit from one to the other power source can be performed by an interlocked operation of the two units without any contact damage and incorrect power source connection.