Display device and vehicle-use display device

A vehicle-use display device arranged in front of a passenger seat comprising:

• an illumination device emitting an illumination light;
• a display panel;
• a viewing angle control panel disposed between the illumination device and the display panel;
• and
• a polarizing axis rotation element disposed between the viewing angle control panel and the display panel, wherein
• the display panel includes a first liquid crystal layer which modulates a first polarization component,
• the viewing angle control panel includes a plurality of first transparent electrodes aligned in a first direction and a second transparent electrode opposed to the first transparent electrodes, a second liquid crystal layer disposed between the first transparent electrodes and the second transparent electrode and containing twist-aligned liquid crystal molecules,
• those of the liquid crystal molecules located in an approximate center of the second liquid crystal layer along a thickness direction thereof are aligned such that the long axis thereof is along the first direction,
• a second polarizing axis of a second polarization component transmitted through the viewing angle control panel is different from a first polarizing axis of the first polarization component,
• the polarizing axis rotation element rotates the second polarizing axis such that the second polarizing axis is aligned with the first polarizing axis,
• the plurality of first transparent electrodes are each rectangular in shape and aligned in the first direction,
• when no voltage is applied to the second liquid crystal layer, the viewing angle control panel transmits light symmetrically to positive and negative viewing angles relative to the normal direction of the viewing angle control panel,
• when the voltage is applied to the second liquid crystal layer, the viewing angle control panel transmits less light to the negative viewing angle than to the positive viewing angle, and a transmittance at the negative viewing angle is smaller than the transmittance at the positive viewing angle at positions where magnitudes of the positive and negative viewing angles are equal each other,
• the first transparent electrodes include a third transparent electrode close to a driver's seat that is aligned with the passenger seat in the first direction and a fourth transparent electrode close to the passenger seat,
• the first transparent electrodes aligned in the first direction are applied with voltages such that the voltages gradually increase from the fourth transparent electrode to the third transparent electrode,
• when the viewing angle control panel is in an off time, when an observation position is tilted to a left side or to a right side, a transmittance of 25% or more is obtained over a range of −40° to +40°, and
• when the viewing angle control panel is in an on time, when the observation position is tilted to one of the right side and the left side, the transmittance of 20% or more is obtained over a range of 0° to +50°, while when the observation position is tilted to the other side of the one of the right side and the left side, the transmittance is 3% or less in a range of 30° or more, and 1% or less in a range of 40° or more.