Ferroelectric liquid crystal panel and method of manufacturing same

• US 5,307,190 A
• Filed: 08/19/1992
• Issued: 04/26/1994
• Est. Priority Date: 08/19/1991
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Uemura, Tsuyoshi, Wakita, Naohide
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MAI, HUY KIM
• Application Number:
  US07/931,992
• Time in Patent Office: 615 Days
• Field of Search: 359/42, 359/46, 359/82, 359/100, 359/49
• US Class Current: 349/158
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/13392 spacers dispersed on the cell substrate, e.g. spherical particles, microfibres
• CPC Class Codes: G02F 1/1341 Filling or closing of cells
• CPC Class Codes: G02F 1/141 using ferroelectric liquid crystals
• CPC Class Codes: G02F 2201/503 Arrangements improving the resistance to shock
• CPC Class Codes: G02F 2201/54 Arrangements for reducing warping-twist

Abstract

A ferroelectric liquid crystal panel includes a first substrate, a second substrate opposed to and spaced from the first substrate, and a ferroelectric liquid crystal interposed between the first and second substrates and having a given layer structure. The second substrate expands and contracts in a direction normal to the layer structure of the liquid crystal according to deformation of the first substrate.

Claims

1. A ferroelectric liquid crystal panel comprising:

a first substrate having a first substrate surface;

a second substrate having a second substrate surface opposed to and spaced from said first substrate; and

a ferroelectric liquid crystal interposed between said first and second substrates and having a given layer structure,

wherein said second substrate expands and contracts in a direction normal to said layer structure of said liquid crystal according to deformation of said substrate, and wherein when a pressure of a value corresponding to the pressure applied to said liquid crystal panel during normal use is applied to said liquid crystal panel, a maximum deviation between said first substrate surface and said second substrate surface is less than 0.6 microns in said direction.

2. The ferroelectric liquid crystal panel according to claim 1, wherein a product of a tensile modulus of elasticity in said direction and a thickness of said second substrate is less than 750 kg/cm.

3. The ferroelectric liquid crystal panel according to claim 2, wherein first and second substrate is made of glass and said second substrate is made of plastic resin.

4. The ferroelectric liquid crystal panel according to claim 3, wherein said fist and second substrates have a thickness greater than 0.55 mm and a thickness less than 0.3 mm, respectively.

5. A display unit having a ferroelectric liquid crystal panel, which comprises:

a first plastic resin film substrate;

a second plastic resin film substrate opposed to and spaced from said first substrate;

a ferroelectric liquid crystal interposed between said first and second substrates and having a given layer structure; and

a pair of protection members disposed in front of and behind said liquid crystal panel, respectively, for protecting said liquid crystal panel,

wherein a product of a tensile modulus of elasticity of said second substrate in a direction normal to said layer structure of said liquid crystal and a thickness of said second substrate is less than 750 kg/cm,

wherein said second substrate expands and contracts in said direction according to deformation of said first substrate, and

wherein when a pressure less than a given value is applied to said liquid crystal panel, said protection members protect said liquid crystal panel from being bent to an extent of exceeding a given curvature, thereby limiting a maximum deviation between a first substrate surface and a second substrate surface to be less than 0.6 micron in said direction.

6. A display unit having a liquid crystal panel, which comprises:

a first glass substrate;

a second plastic resin film substrate opposed to and spaced from said first substrate;

a plurality of electrodes formed on an internal surface of said first substrate;

a plurality of electrodes formed on an internal surface of said second substrate;

a liquid crystal interposed between said first and second substrates, thereby providing a display on a side of said first substrate; and

a frame for supporting said liquid crystal panel at a peripheral portion thereof, wherein a space is defined between said frame and said second substrate;

wherein said liquid crystal panel comprises a ferroelectric liquid crystal panel and wherein a product of a tensile modulus of elasticity of said second substrate in a direction normal to a layer structure of said liquid crystal and a thickness of said second substrate is less than 750 kg/cm.

7. A method of manufacturing a liquid crystal panel having first and second substrates, at least one of which comprises a plastic resin film, said method comprising the steps of:

coating an ultraviolet-curable sealant on a peripheral portion of at least one of said substrates so that said sealant encircles a display region;

uniformly distributing a given amount of a liquid crystal over said second substrate;

bonding and pressing said substrates in a vacuum chamber; and

applying ultraviolet rays to said sealant, thereby hardening said sealant.

8. The method according to claim 7, further comprising, prior to said step of bonding and pressing, the steps of scattering a number of spacers coated with an adhesive on said first substrate and bonding said spacers to said first substrate without bonding said spacers to said second substrate.

9. The method according to claim 8, wherein said liquid crystal is a ferroelectric liquid crystal.

10. The method according to claim 8, wherein said given amount of said liquid crystal is 1% to 3% less than a product of an area inside said sealant and a diameter of said spacers.

11. The method according to claim 10, wherein said liquid crystal is a ferroelectric liquid crystal.

12. The method according to claim 10, wherein said first substrate comprises a glass plate whereas said second substrate comprises a plastic resin film, wherein said first substrate is placed on said second substrate via said sealant within said vacuum chamber, and wherein a pressure is applied to said first substrate radially outwardly from a central portion thereof by an elastic member.

13. The method according to claim 12, wherein said liquid crystal is a ferroelectric liquid crystal.

14. The method according to claim 7, wherein said liquid crystal is a ferroelectric liquid crystal.