Method and arrangement for accomplishing a function in an electronic apparatus and an electronic apparatus

• US 20020075239A1
• Filed: 12/10/2001
• Published: 06/20/2002
• Est. Priority Date: 12/15/2000
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Potkonen, Ari
• Granted Patent: US 6,750,849 B2
• Time in Patent Office: Days
• US Class Current: 345/168
• CPC Class Codes: G06F 3/0426 tracking fingers with respect to a virtual keyboard projected or printed on the surface virtual keyboards on touch screens G06F3/04886

Abstract

The invention relates to a method and arrangement for generating a virtual keyboard in connection with an electronic apparatus (10) on a planar surface (16). The virtual keyboard is drawn by a laser transmitter (11), and the light reflected from an obstacle (15b) in the area of the virtual keyboard is received. The angle of incidence and time of arrival of the received signal are observed, and on the basis thereof a conclusion is drawn about whether a certain key in the virtual keyboard has been pressed.

Claims

1. A method for accomplishing a function in an electronic apparatus housed within a body, which method comprises

a step of drawing a virtual keyboard on a plane by means of radiation visible to the eye,

where the source of radiation visible to the eye comprises at least one laser transmitter emitting a beam of light which both draws the desired key pattern and observes the position of an obstacle in the key pattern,

a step of placing an obstacle in the keyboard pattern produced,

a step of receiving radiation reflected from the obstacle, and

a step of determining the position of the obstacle on the basis of the signal received.

2. A method according to claim 1 wherein the same laser transmitter is used in the drawing of the virtual keyboard and in the recognition of the position of an obstacle.

3. A method according to claim 1 wherein to determine the position of the obstacle the angle of incidence and the reception time of the received reflected signal are measured, and if they are within a predetermined limit value range and if a sufficient number of successive drawing scans produce a reflection, it is concluded that a virtual key has been pressed.

4. A method according to claim 1 which further comprises a step in which, after receiving a signal reflected from an obstacle, the drawing power of the laser transmitter is reduced for as long a time as the signal reflected from the obstacle can be received.

5. A method according to claim 4 which further comprises a step in which the position of the signal reflected from an obstacle is stored as an indicator in the memory of the electronic apparatus.

6. A method according to claim 5 which further comprises a step in which the power of the laser transmitter is always reduced at positions according to the indicators stored in the memory of the electronic apparatus when the virtual keyboard is drawn the next time.

7. A method according to claim 4 which further comprises a step for gradually raising the drawing power in the next drawing rounds back to the original drawing power after it is detected that the reflection has been removed.

8. An arrangement for accomplishing a function in an electronic apparatus housed within a main body, which arrangement comprises a means for generating and using a virtual keyboard produced on a planar input area outside the main body of the apparatus, where the said means comprises a laser transmitter for drawing a virtual keyboard and observing the position of an obstacle, and a receiver for receiving radiation/light reflected from an obstacle in the virtual keyboard, which comprises at least one row of virtual keys.

9. An arrangement according to claim 8 which further comprises a means for determining the reception angle and reception time of radiation/light reflected from an obstacle.

10. An arrangement according to claim 9 which further comprises a means for comparing the reception angle, reception time and the number of successive drawing scans that produced reflections, with predetermined limit values in order to recognize the operation of a virtual key.

11. An arrangement according to claim 8 wherein the drawing of the virtual keyboard and observation of the position of an obstacle are carried out by separate laser transmitters.

12. An arrangement according to claim 8 which further comprises a means for preventing the operation of a laser transmitter in the electronic apparatus if the position of the electronic apparatus relative to the plane used as a drawing platform is not within the allowed range of limit values.

13. An arrangement according to claim 8 which further comprises a means for reducing the power of a laser transmitter when a reflection has been received from the radiation field of the laser transmitter.

15. A terminal according to claim 14 wherein the means for observing the position of an obstacle in the virtual keyboard comprises

means for determining the reception angle and reception time of a received signal,

means for determining the validity of the reception angle,

means for determining the validity of the reception time,

means for counting the successive reflection signals received at different scanning rounds and for estimating whether a sufficient number of reflections have been received, and

means for detecting a press of a key in the virtual keyboard.

16. A terminal according to claim 15 wherein the means for observing the position of an obstacle in the virtual keyboard further comprises a portion allocated from the memory of a drawing control unit connected to the terminal for storing indicators caused by reflected signals for the next scanning round.

14. A cellular network terminal, comprising

means for receiving signals,

means for transmitting signals,

means for controlling the operation of the terminal,

memory for storing programs, and

means for producing a virtual keyboard and observing an obstacle in the virtual keyboard, said means comprising a laser transmitter and a receiver for receiving radiation/light reflected from an obstacle and a drawing control unit.

17. Software means for recognizing the position of an obstacle in the area of a virtual keyboard of an electronic apparatus, which software means comprises

a step of determining the reception angle and reception time of a received signal,

a step of determining the validity of the reception angle,

a step of determining the validity of the reception time,

a step of counting the successive reflection signals received at different scanning rounds and estimating whether a sufficient number of reflections have been received, and

a step of detecting a press of a key in the virtual keyboard.