Mobile station and cover for mobile station having thermochromic liquid crystals

• US 6,466,299 B1
• Filed: 12/27/1999
• Issued: 10/15/2002
• Est. Priority Date: 12/30/1998
• Status: Expired due to Fees

• Current Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Paldanius, Juha, Lehtiniemi, Reijo
• Primary Examiner(s): Ton, Toan
• Assistant Examiner(s): SCHECHTER, ANDREW M
• Application Number:
  US09/473,250
• Time in Patent Office: 1,023 Days
• Field of Search: 349/20, 349/72, 349/199
• US Class Current: 349/199
• CPC Class Codes: H04M 1/0283 for providing a decorative aspect, e.g. customization of casings, exchangeable faceplate

Abstract

The cover or keyboard of an electronic device or a portable mobile station is coated or mixed to include liquid crystals changing color with changes of temperature, or thermochromic liquid crystals (TLC). Thermochromic liquid crystals can be used to implement reversible or irreversible color changes on several different color change temperature ranges. The cover (C) changes its color when changing temperature forming patterns (A1) following heat gradients, in its TLC-comprising parts. The color change indicates both heat applied externally to the mobile station and the heating caused by the internal energy consumption of the mobile station.

Claims

1. A mobile station with a cover, wherein the cover comprises:

thermochromic liquid crystals capable of color change in order to bring about at least a partially reversible change of color in response to a change in a temperature of the cover.

2. A mobile station according to claim 1, wherein said thermochromic liquid crystals have been micro-capsulated.

3. A mobile station according to claim 1, wherein the cover comprises thermochromic liquid crystals on a defined area that is at least a part of the externally visible area of the cover.

4. A mobile station according to claim 1, wherein said cover comprises an outer surface and the cover comprises at least one of the following for forming a pattern of color change visible on the external surface;

thermochromic liquid crystals spread unevenly with respect to the external surface of the cover in order to form a pattern that changes color as a function of temperature;

at least two different types of thermochromic liquid crystals unevenly spread with respect to the external surface of the cover, changing their color differently with a similar change of temperature, in order to form at least two different patterns visible in different temperatures;

thermochromic liquid crystals mixed into the cover material unevenly spread along the thickness axis of the cover material;

a substantially opaque layer of pigment unevenly covering the thermochromic liquid crystals comprised by the cover material, in order to cover some of the liquid crystals;

unhomogenically heat-conducting parts in order to spread the heat load on the cover material unevenly with respect to the external surface in order to spread the heat power of the thermochromic liquid crystals in an uneven way, in order to produce a patterned color change;

parts differing from their surroundings in their heat capacity in order to spread the heat load on the cover material unevenly with respect to the external surface in order to spread the heat power of the thermochromic liquid crystals in an uneven way, in order to produce a patterned color change; and

thickness changes in order to spread the heat load on the cover material with respect to the external surface in order to spread the heat power of the thermochromic liquid crystals in an uneven way, in order to produce a patterned color change.

5. A mobile station according to claim 1, wherein the cover comprises an external surface visible outward from the mobile station and an internal surface inwards into the mobile station;

and

the cover comprises at least one of the following;

on its external surface, a coating material comprising thermochromic liquid crystals;

on its internal surface, a coating material comprising thermochromic liquid crystals and a part of the cover is at least partially transparent in order to make the color changes in the liquid crystals inside visible to outside;

thermochromic liquid crystals mixed into the cover in order to make visible the color changes in at least those liquid crystals near the external surface; and

thermochromic liquid crystals changing color in at least two different temperature ranges joined into a substantially same visible area of the cover in order to increase the temperature range of the color change.

6. A mobile station according to claim 1, wherein said mobile station comprises a power source and a load formed by at least one electronic component that consumes variable amounts of power from the power source;

and

said color change indicates the power consumed by the load from the power source.

7. A mobile station according to claim 1, wherein the color change of said thermochromic liquid crystals of the cover has been arranged to take place when the mobile station reaches a temperature harmfully high or low to the operation of the mobile station.

8. A cover to a mobile station, wherein the cover comprises thermochromic liquid crystals capable of at least partially reversible color change in order to cause a color change in the cover in response to a temperature change in the cover.

9. A cover according to claim 8, wherein said thermochromic liquid crystals have been micro encapsulated.

10. A cover according to claim 8, wherein said cover comprises an external surface and said cover comprises, in order to form a patterned change in color visible on the external surface, at least one of the following:

thermochromic liquid crystals spread unevenly with respect to the external surface of the cover in order to form a pattern that changes color in a function of temperature;

at least two different types of thermochromic liquid crystals unevenly spread with respect to the external surface of the cover, changing their color differently with a similar change of temperature, in order to form at least two different patterns visible in different temperatures;

thermochromic liquid crystals mixed into the cover material unevenly spread along the thickness axis of the cover material;

a substantially opaque layer of pigment unevenly covering the thermochromic liquid crystals comprised by the cover material, in order to cover some of the liquid crystals;

unhomogenically heat-conducting parts in order to spread the heat load on the cover material unevenly with respect to the external surface in order to spread the heat power of the thermochromic liquid crystals in an uneven way, in order to produce a patterned color change;

parts differing from their surroundings in their heat capacity in order to spread the heat load on the cover material unevenly with respect to the external surface in order to spread the heat power of the thermochromic liquid crystals in an uneven way, in order to produce a patterned color change; and

thickness changes in order to spread the heat load on the cover material with respect to the external surface in order to spread the heat power of the thermochromic liquid crystals in an uneven way, in order to produce a patterned color change.

11. A method for changing at least partially reversibly a color of a mobile station with a cover, comprising the steps of:

introducing in the cover thermochromic liquid crystals capable of color change; and

subjecting the cover to a change of temperature, whereby the color of the cover changes as a response to the change of temperature in the cover.

12. A method according to claim 11, wherein

the cover comprises an external surface visible outward from the mobile station and an internal surface into the mobile station; and

the application of the thermochromic liquid crystals comprises at least one of the following;

coating the external surface of the cover with a coating material containing thermochromic liquid crystals;

coating the internal surface of an at least partially transparent cover with a coating material containing thermochromic liquid crystals;

mixing thermochromic liquid crystals into the basic material of the cover when it is manufactured; and

applying thermochromic liquid crystals that change their color on at least two different temperature ranges onto the external surface of the cover in order to increase the temperature range of the color change.

13. An electronic device comprising:

a cover;

wherein the cover includes thermochromic liquid crystals capable of color change in order to bring about at least a partially reversible change of color in response to a change in a temperature of the cover; and

a keyboard with at least one key;

the keyboard including thermochromic liquid crystals arranged on at least one part of one key on the keyboard to indicate a use of the key.

14. The electronic device of claim 13, wherein the thermochromic liquid crystals are arranged on a part of the cover surrounding the key.

15. A mobile station with a cover, wherein the cover comprises thermochromic liquid crystals capable of color change in order to bring about at least partially reversibly change of color in response to a change in a temperature of the cover caused by a user touching the cover to indicate use of the mobile station, and the thermochromic liquid crystals are contained in a coating applied on the cover or mixed into a cover material.

16. A mobile station according to claim 15, wherein thermochromic liquid crystals are arranged to change color in response to temperature change caused by one of:

a user'"'"'s hand, a user'"'"'s finger, the mobile station being in a user'"'"'s pocket, or the mobile station being pressed against a user'"'"'s ear or cheek.

17. A cover for a mobile station, wherein the cover comprises thermochromic liquid crystals capable of at least partially reversible color change in order to cause a color change in the cover in response to a temperature change in the cover caused by a user touching the cover to indicate use of the mobile station, and the thermochromic liquid crystals are contained in a coating applied on the cover or mixed into a cover material.

18. A method for indicating use of a mobile station, wherein the method comprises the steps of:

introducing into a cover of the mobile station thermochromic liquid crystals capable of color change as a response to a change of temperature; and

subjecting the cover to a change of temperature by a user touching the cover, wherein a color of the cover changes as a response to the change of temperature in the cover caused by the user to indicate use of the mobile station.