Pointing device and portable information terminal using the same

• US 20020030668A1
• Filed: 08/16/2001
• Published: 03/14/2002
• Est. Priority Date: 08/21/2000
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hoshino, Takeshi, Asada, Yukinori, Maruyama, Yukinobu
• Granted Patent: US 7,239,304 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A pointing device is placed in a through hole provided on an outer case of the portable information terminal. The portable information terminal includes a fingerplate attached to a through hole via a hinge 4e; an image pick-up element placed on a circuit board; a condensing lens that forms an image on an outer surface of the fingerplate on an image pick-up plane of the image pick-up element; and a light emitting device that irradiates the outer surface of the fingerplate with illumination light, and takes the image of a pattern such as a fingerprint of a fingertip that touches the outer surface of the fingerplate by using the image pick-up element. When the fingertip moves while touching the fingerplate, the image taken by the image pick-up element changes and the pointer displayed on a display screen is moved in a direction according to a change direction and by a distance corresponding to a quantity of change.

Claims

1. A pointing device for moving a pointer shown on a display screen, comprising:

a transparent plate having an outer surface to contact a surface of an object;

image detecting means for detecting an image of the surface of said object that contacts an outer surface of said plate; and

optical means for forming an image on the outer surface of said plate on a detection plane of said image detecting means,

wherein said pointer is configured to be able to move according to a movement of the image on the outer surface of said plate detected by said image detecting means.

2. A portable information terminal provided with a pointing device according to claim 1, comprising means for detecting a movement of said image detected by said image detecting means and moving said pointer in a direction according to the direction of said detected movement.

3. A portable information terminal provided with a pointing device according to claim 1, comprising means for determining a presence/absence of movement of the image on the outer surface of said plate detected by said image detecting means and switching a sensing frequency of said image detecting means according to the determination result.

4. The pointing device according to claim 1, comprising light emitting means for emitting light onto the outer surface of said plate.

5. A portable information terminal provided with a pointing device according to claim 4, further comprising:

first means for measuring a reflection factor of said plate on the outer surface from the quantity of light received of said image detecting means and the quantity of light emitted of said light emitting means;

second means for designating a quantity of light emitted of said light emitting means as a first reference value when the reflection factor measured by said first means falls below a predetermined minimum reference value and adjusting the quantity of light emitted of said light emitting means when the reflection factor measured by said first means exceeds said minimum reference value so that the quantity of light received by said image detecting means becomes a predetermined second reference value which is larger than said first reference value;

third means for detecting a movement of said image detected by said image detecting means and moving said pointer in the direction according to the direction of said detected movement; and

fourth means for determining a presence/absence of movement of said image detected by said image detecting means, setting said pointing device in an action mode when said movement is detected, moving said pointer in the direction according to the direction of said movement and setting said pointing device in a standby mode when said movement is not detected for a predetermined period of time,

wherein the sensing frequency of said pointing device in said standby mode is smaller than the sensing frequency of said pointing device in said action mode.

6. The portable information terminal provided with a pointing device according to claim 5, wherein said second means temporarily changes a quantity of light emitted of said light emitting means when the reflection factor measured by said first means falls below a predetermined minimum reference value and designates the quantity of light emitted of said light emitting means as the predetermined first reference value when the quantity of light received of said image detecting means does not change as said quantity of light emitted changes.

7. The portable information terminal provided with a pointing device according to claim 6, wherein said plate of said pointing device allows a pushing operation and comprises at least one operation switch that operates in accordance with said pushing operation.

8. The portable information terminal provided with a pointing device according to claim 7, wherein one of said operation switches is an “

Enter”

switch to enter a menu on said display screen indicated by said pointer.

9. The portable information terminal provided with a pointing device according to claim 8,

wherein optical means of said pointing device is a first condensing lens that forms an image on the outer surface of said plate on the detection plane of said image detecting means, and

said image detecting means is an image pick-up element, and there are provided:

a second condensing lens with a focal distance different from that of said first condensing lens; and

means for switching between said first and second condensing lenses and inserting between said plate and said image pick-up element, and

said image pick-up element is configured to be able to pick up images of an object by said second condensing lens at a greater distance than the outer surface of said plate.

10. The portable information terminal provided with a pointing device according to claim 8, wherein optical means of said pointing device is a condensing lens capable of switching between a first focal distance at which the image on the outer surface of said plate is formed on the detection plane of said image detecting means and a second focal distance longer than said first focal distance, and

said image detecting means is an image pickup element and is configured to be able to pick up the image of an object by said image pick-up element at a longer distance than the outer surface of said plate by setting the focal distance of said condensing lens to said second focal distance.