Optical shutter for display device, image display apparatus, and apparatus and method for manufacturing the optical shutter

An image display apparatus comprising:

• a light source;
• and
• an image display unit configured to transmit light emitted from the light source,
• wherein the image display unit has an optical shutter for controlling the amount of transmission of the light emitted from the light source, the optical shutter including
• a partition wall configured to surround and isolate a light-transmitting portion through which the light is transmitted;
• a polar liquid having polarity, allowing transmission of light, and placed at the light-transmitting portion surrounded by the partition wall;
• a nonpolar liquid having no polarity, blocking transmission of light, and placed at the light-transmitting portion surrounded by the partition wall;
• an insulator having hydrophobic properties and disposed over the entire light-transmitting portion surrounded by the partition wall;
• a first electrode;
• and
• a second electrode different from the first electrode,
• wherein when no voltage is applied across the first electrode and the second electrode, the nonpolar liquid spreads near the insulator, becomes stable, and thus blocks transmission of the light;
• when a voltage is applied across the first electrode and the second electrode, the polar liquid gravitates toward the insulator because of a change in wettability of the insulator against the polar liquid and causes the nonpolar liquid to collect in a part of the light-transmitting portion according to the level of the voltage, thereby controlling the amount of transmission of the light;
• and
• the following conditions are satisfied,
• 100 μm2≦A≦30000 μm2
• 1 μm≦H≦10 μm
• where A denotes the area of a light-transmitting surface of the light-transmitting portion surrounded by the partition wall, the light-transmitting surface being orthogonal to a traveling direction of the light, and H denotes the height of the partition wall.

An optical shutter manufacturing apparatus for manufacturing an optical shutter for controlling the amount of transmission of light emitted from a display device, the optical shutter manufacturing apparatus comprising:

• partition wall forming means for forming, on a transparent substrate, a partition wall for surrounding and isolating a light-transmitting portion through which the light is transmitted,
• wherein the partition wall forming means forms the partition wall such that the optical shutter satisfies the following conditions,
• 100 μm2≦A≦30000 μm2
• 1 μm≦H≦10 μm,
• where A denotes the area of a light-transmitting surface of the light-transmitting portion surrounded by the partition wall, the light-transmitting surface being orthogonal to a traveling direction of the light, and H denotes the height of the partition wall.

An optical shutter manufacturing method carried out by an optical shutter manufacturing apparatus for manufacturing an optical shutter for controlling the amount of transmission of light emitted from a display device, the optical shutter manufacturing method comprising the step of:

• forming, on a transparent substrate, a partition wall for surrounding and isolating a light-transmitting portion through which the light is transmitted,
• wherein the partition wall is formed such that the following conditions are satisfied,
• 100 μm2≦A≦30000 μm2
• 1 μm≦H≦10 μm,
• where A denotes the area of a light-transmitting surface of the light-transmitting portion surrounded by the partition wall, the light-transmitting surface being orthogonal to a traveling direction of the light, and H denotes the height of the partition wall.

An optical shutter for controlling the amount of transmission of light emitted from a display device, the optical shutter comprising:

• a partition wall configured to surround and isolate a light-transmitting portion through which the light is transmitted;
• a polar liquid having polarity, allowing transmission of light, and placed at the light-transmitting portion surrounded by the partition wall;
• a nonpolar liquid having no polarity, blocking transmission of light, and placed at the light-transmitting portion surrounded by the partition wall;
• an insulator having hydrophobic properties and disposed over the entire light-transmitting portion surrounded by the partition wall;
• a first electrode;
• and
• a second electrode different from the first electrode,
• wherein when no voltage is applied across the first electrode and the second electrode, the nonpolar liquid spreads near the insulator, becomes stable, and thus blocks transmission of the light;
• and
• when a voltage is applied across the first electrode and the second electrode, the polar liquid gravitates toward the insulator because of a change in wettability of the insulator against the polar liquid and causes the nonpolar liquid to collect in a part of the light-transmitting portion according to the level of the voltage, thereby controlling the amount of transmission of the light.

An image display apparatus comprising:

• a light source;
• and
• an image display unit configured to transmit light emitted from the light source,
• wherein the image display unit has an optical shutter for controlling the amount of transmission of the light emitted from the light source, the optical shutter including
• a partition wall configured to surround and isolate a light-transmitting portion through which the light is transmitted;
• a polar liquid having polarity, allowing transmission of light, and placed at the light-transmitting portion surrounded by the partition wall;
• a nonpolar liquid having no polarity, colored in at least one of red, green and blue, and placed at the light-transmitting portion surrounded by the partition wall;
• an insulator having hydrophobic properties and disposed over the entire light-transmitting portion surrounded by the partition wall;
• a first electrode;
• and
• a second electrode different from the first electrode,
• wherein when no voltage is applied across the first electrode and the second electrode, the nonpolar liquid spreads near the insulator, becomes stable, and thus blocks transmission of the light;
• and
• when a voltage is applied across the first electrode and the second electrode, the polar liquid gravitates toward the insulator because of a change in wettability of the insulator against the polar liquid and causes the nonpolar liquid to collect in a part of the light-transmitting portion according to the level of the voltage, thereby controlling the amount of transmission of the light.