MOVIE PROJECTION SYSTEM

• US 20080272912A1
• Filed: 04/09/2008
• Published: 11/06/2008
• Est. Priority Date: 05/01/2007
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: ISHIDA, Tessho
• Granted Patent: US 7,884,716 B2
• Time in Patent Office: Days
• US Class Current: 340/545.6
• CPC Class Codes: G08B 13/08 by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind

Abstract

In a movie projection system, a switch circuit is disposed on a door of a case in which a video server is disposed. A tamper detector detects a state of the door as to whether the door is open or not and a state of the switch circuit as to whether the switch circuit has been tampered with or not, on the basis of an output signal provided by the switch circuit. A projecting operation controller controls the operation of the movie projection system such that when the door is detected to be in the open state or the switch circuit is detected to have been tampered with, the projecting operation controller stops inputting and outputting video data to or from the video server.

Claims

1. A movie projection system comprising:

a switch circuit disposed on a door of a case in which a video server is disposed;

a tamper detector adapted to detect a state of the door as to whether the door is open or not and a state of the switch circuit as to whether the switch circuit has been tampered with or not, on the basis of an output signal provided by the switch circuit; and

a projecting operation controller adapted to control the operation of the movie projection system such that when the door is detected to be in the open state or the switch circuit is detected to have been tampered with, the projecting operation controller stops inputting and outputting video data to or from the video server.

2. The movie projection system according to claim 1, wherein when the door is detected to be in the open state or the switch circuit is detected to have been tampered with, the projecting operation controller disables reading of the video data from a data storage unit in which the video data is stored.

3. The movie projection system according to claim 1, wherein

the switch circuit includes an SPDT switch adapted to switch between two signal paths in synchronization with opening of the door;

and

the tamper detector detects the state of the door as to whether the door is open or not or the state of the switch circuit as to whether the switch circuit has been tampered with, on the basis of two output signals supplied from the switch circuit.

4. The movie projection system according to claim 3, wherein the switch circuit includes

an exclusive OR circuit with two inputs respectively connected to the two signal paths, and

an AND circuit with two inputs one of which is connected to one of the two signal path and the other is connected to an output of the exclusive OR circuit.

5. The movie projection system according to claim 4, wherein the tamper detector detects the state of the door as to whether the door is open or not and the state of the switch circuit as to whether the switch circuit has been tampered with, on the basis of an output signal provided by the exclusive OR circuit disposed in the switch circuit and an output signal of the AND circuit disposed in the switch circuit.

6. The movie projection system according to claim 5, wherein when the tamper detector detects that the output signal provided by the exclusive OR circuit disposed in the switch circuit or the output signal provided by the AND circuit disposed in the switch circuit has an abnormal value, the tamper detector determines that the door is in the open state or the switch circuit has been tampered with.

7. The movie projection system according to claim 1, wherein the switch circuit includes

a plurality of switch units respectively disposed on a plurality of doors disposed in the case, and

an electric circuit unit connected to the plurality of switch units and adapted to detect states of the doors as to whether any of the doors is open or not and states of the switch units as to whether any of the switch units has been tampered with or not.

8. The movie projection system according to claim 7, wherein

each switch unit includes

a SPDT switch adapted to switch between two signal paths, and

a first output terminal and a second output terminal via which to electrically connect the two signal paths to the electric circuit unit, and

the electric circuit unit includes

a plurality of first input terminals respectively connected to the first output terminals of the plurality of switch units,

a plurality of second input terminals respectively connected to the second output terminals of the plurality of switch units,

a first AND circuit with inputs respectively connected to the outputs of the plurality of first input terminals,

a second AND circuit with inputs respectively connected to the outputs of the plurality of second input terminals,

an exclusive OR circuit with inputs respectively connected to the output of the first AND circuit and the output of the second AND circuit, and

a third AND circuit with inputs respectively connected to the output of the first AND circuit and the output of the exclusive OR circuit.

9. The movie projection system according to claim 8, wherein the tamper detector detects the states of the doors as to whether any of the doors is open or not and states of the switch units as to whether any of the switch units has been tampered with or not, on the basis of the output signal provided by the exclusive OR circuit disposed in the switch circuit and the output signal provided by the third AND circuit disposed in the switch circuit.

10. The movie projection system according to claim 9, wherein when the tamper detector detects that the output signal provided by the exclusive OR circuit disposed in the switch circuit or the output signal provided by the third AND circuit disposed in the switch circuit has an abnormal value, the tamper detector determines that one or more of the doors are in the open state or one or more of the switch circuits have been tampered with.