Projector device with theft prevention function and theft preventing method

• US 20060164242A1
• Filed: 01/24/2006
• Published: 07/27/2006
• Est. Priority Date: 01/25/2005
• Status: Active Grant

• Current Assignee: NEC Display Solutions, Ltd. (NEC Corporation)
• Original Assignee: NEC Viewtechnology, Ltd.
• Inventors: Aoyanagi, Hisakazu
• Granted Patent: US 7,429,930 B2
• Time in Patent Office: Days
• US Class Current: 340/568.100
• CPC Class Codes: G08B 13/1418 Removal detected by failure in electrical connection between the appliance and a control centre, home control panel or a power supply
• CPC Class Codes: G08B 13/1436 with motion detection
• CPC Class Codes: G08B 21/0213 System disabling if a separation threshold is exceeded disabling electrical appliances in case of unplugging G08B13/1409
• CPC Class Codes: G08B 21/0236 Threshold setting
• CPC Class Codes: G08B 21/0261 System arrangements wherein the object is to detect trespassing over a fixed physical boundary, e.g. the end of a garden

Abstract

X-direction double integrator 3 integrates twice an acceleration that is detected by x-direction acceleration sensor 1, estimating a traveled distance in an x direction. Y-direction double integrator 4 integrates twice an acceleration that is detected by y-direction acceleration sensor 2, estimating a traveled distance in a y direction. Detection boundary storage unit 5 stores a monitoring area. Detection boundary comparator 6 determines whether the projector device is positioned outside of the monitoring area or not based on the traveled distance in the x direction which is estimated by x-direction double integrator 3, the traveled distance in the y direction which is estimated by y-direction double integrator 4, and the monitoring area stored in detection boundary storage unit 5.

Claims

1. A projector device with a theft prevention function, comprising:

a position detecting unit that detects a present position of the projector device;

an area input unit that receives a monitoring area;

an area storage unit that stores the monitoring area received by said area input unit; and

a detecting unit that detects whether said projector device is positioned outside said monitoring area or not based on the present position of said projector device detected by said position detecting unit and the monitoring area stored by said area storage unit.

2. A projector device according to claim 1, wherein said monitoring area includes an initial position of said projector device;

and

wherein said position detecting unit comprises;

an acceleration detecting unit that detects accelerations of said projector device in two different directions; and

a traveled distance estimating unit that estimates traveled distances respectively in said two different directions of said projector from said initial position, based on the accelerations detected by said acceleration detecting unit.

3. A projector device according to claim 1, wherein said area input unit comprises:

a boundary input unit that receives a boundary for specifying said monitoring area; and

a distance input unit that receives a distance as the radius of a circular area which serves as said monitoring area around said initial position at a center thereof.

4. A projector device according to claim 3, wherein said detecting unit comprises:

a boundary detecting unit that detects whether said projector device is positioned outside said monitoring area or not based on the boundary of the monitoring area received by said boundary input unit and the present position of said projector device detected by said position detecting unit;

a linear distance estimating unit that estimates a linear distance between the present position of said projector device detected by said position detecting unit and said initial position; and

a distance detecting unit that detects whether said projector device is positioned outside said monitoring area or not based on the distance received by said distance input unit and the linear distance estimated by said linear distance estimating unit.

5. A projector device according to claim 1, further comprising:

an alarm generating unit that generates an alarm when said projector device is positioned outside said monitoring area.

6. A projector device according to claim 1, further comprising:

a device function disabling unit that stops image projecting operation of said projector device when said projector device Is positioned outside said monitoring area.

7. A projector device according to claim 5, further comprising:

a battery including a chargeable battery; and

a power supply detecting unit that detects whether there is electric power supplied from a power cable or not;

wherein said battery supplies electric power to said position detecting unit, said detecting unit, and said alarm generating unit if said power supply detecting unit detects when there is no electric power supplied from the power cable.

8. A projector device according to claim 6, further comprising:

a battery including a chargeable battery; and

a power supply detecting unit that detects whether there is electric power supplied from a power cable or not;

wherein said battery supplies electric power to said position detecting unit, said detecting unit, and said alarm generating unit if said power supply detecting unit detects when there is no electric power supplied from the power cable.

9. A projector device according to claim 7, further comprising:

a non-volatile memory;

a battery power detecting unit that detects a voltage drop of said battery; and

a battery power turn-off detecting unit that stores information representative of no supply of electric power in said non-volatile memory when the voltage drop of said battery is detected by said battery power detecting unit, and outputting the information stored in said non-volatile memory when the electric power resumes being supplied from the power cable.

10. A projector device with a theft prevention function, comprising:

position detecting means for detecting a present position of the projector device;

area input means for receiving a monitoring area;

area storage means for storing the monitoring area received by said area input means; and

detecting means for detecting whether said projector device is positioned outside said monitoring area or not based on the present position of said projector device detected by said position detecting means and the monitoring area stored by said area storage means.

11. A theft prevention method for being performed by a projector device, comprising:

a) detecting a present position of the projector device;

b) receiving a monitoring area;

c) storing the monitoring area received in said step b); and

d) detecting whether said projector device is positioned outside said monitoring area or not based on the present position of said projector device detected in said step a) and the monitoring area stored in said step c).

12. A theft prevention method according to claim 11, wherein said monitoring area includes an initial position of said projector device;

and

wherein said step a) comprises;

e) detecting accelerations of said projector device in two different directions; and

f) estimating traveled distances respectively in said two different directions of said projector from said initial position, based on the accelerations detected in said step e).

13. A theft prevention method according to claim 11, wherein said step b) comprises:

g) receiving a boundary for specifying said monitoring area; and

h) receiving a distance as the radius of a circular area which serves as said monitoring area around said initial position at a center thereof.

14. A theft prevention method according to claim 13, wherein said step d) comprises:

i) detecting whether said projector device Is positioned outside said monitoring area or not based on the boundary of the monitoring area received in said step g) and the present position of said projector device detected in said step a);

j) estimating a linear distance between the present position of said projector device detected in said step a) and said initial position; and

k) detecting whether said projector device is positioned outside said monitoring area or not based on the distance received in said step h) and the linear distance estimated in said step j).

15. A theft prevention method according to claim 11, further comprising:

l) generating an alarm when said projector device is positioned outside said monitoring area.

16. A theft prevention method according to claim 11, further comprising:

m) stopping image projecting operation of said projector device when said projector device is positioned outside said monitoring area.

17. A theft prevention method according to claim 15, wherein said projector device has a battery including a chargeable battery, a position detecting unit that executes said step a), a detecting unit that executes said step d), and an alarm generating unit that executes said step 1), said theft prevention method further comprising:

n) detecting whether there is electric power supplied from a power cable or not; and

o) supplying electric power from said battery to said position detecting unit, said detecting unit, and said alarm generating unit if said step n) detects when there is no electric power supplied from the power cable.

18. A theft prevention method according to claim 16, wherein said projector device has a battery including a chargeable battery, a position detecting unit that executes said step a), a detecting unit that executes said step d), and an alarm generating unit that executes said step 1), said theft prevention method further comprising:

n) detecting whether there is electric power supplied from a power cable or not; and

o) supplying electric power from said battery to said position detecting unit, said detecting unit, and said alarm generating unit if said step n) detects when there is no electric power supplied from the power cable.

19. A theft prevention method according to claim 17, wherein said projector device has a non-volatile memory, said theft prevention method further comprising:

p) detecting a voltage drop of said battery; and

q) storing information representative of no supply of electric power in said non-volatile memory when the voltage drop of said battery is detected in said step p), and outputting the information stored In said non-volatile memory when the electric power resumes being supplied from the power cable.