PC analog output signal control for copy protect

• US 6,370,318 B1
• Filed: 10/21/1998
• Issued: 04/09/2002
• Est. Priority Date: 10/31/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Iwaki, Tsutomu
• Primary Examiner(s): NGUYEN, HUY THANH
• Application Number:
  US09/176,097
• Time in Patent Office: 1,266 Days
• Field of Search: 386/46, 386/94, 386/95, 386/125, 386/126, 380/201, 380/203, 380/210, 708/100
• US Class Current: 386/252
• CPC Class Codes: H04N 2005/91314 the copy protection signal being a pulse signal inserted in blanking intervals of the video signal, e.g. pseudo-AGC pulses, pseudo-sync pulses
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection

Abstract

When a copy-inhibited source such as a DVD title or a digital satellite broadcast is inputted, or a DVD-ROM drive is loaded, output of an image signal for an external CRT display or a TV image signal by a VGA controller is inhibited by generating a protect signal under the control of hardware or software, disabling a buffer, a DAC, and a TV encoder, and switching a selector. Accordingly, illicit copying of an image source using output of an image signal for an external image unit can be prevented.

Claims

1. A computer comprising:

a decoder configured to decode coded image data and output decoded image data in an interlaced form;

a protect signal generator configured to determine if the coded image data requires a copy protect, and produce a copy protect signal when the coded image requires a copy protect;

a copy protect circuit configured to perform copy protect processing on the decoded image data output from the decoder in response to the copy protect signal, and

supply copy protected image data to an external display coupled to an external interface;

a video graphic controller connected to the decoder and configured to convert the decoded image data to graphic data in a non-interlaced form, and supply the graphic data to an internal display and to the external display,

wherein the video graphic controller does not supply the graphic data to the external display in response to the copy protect signal; and

a selector configured to select one of the copy protected image data and the graphic data based on the copy protect signal, and

supply the selected data to the external display,

wherein the selector selects the copy protected image data output from the copy protect circuit in response to the copy protect signal.

2. The computer according to claim 1, wherein said video graphic controller comprises a television encoder that converts the decoded image data to television image data that can be displayed by an external display connected to the external interface,

wherein operation of the encoder is halted in response to the copy protect signal.

3. The computer according to claim 1, wherein said video graphic controller comprises a buffer connected to an internal interface and operatively configured to halt in response to the copy protect signal.

4. The computer according to claim 1, wherein said protect signal generator comprises:

a device bay in which a disk drive for reading the coded image signal from a disk medium is loaded;

a sense switch that is activated in response to a loading of a DVD drive; and

a switch determining circuit which determines that the coded image data requires a copy protect in response to the activation of the sense switch.

5. The computer according to claim 1, wherein said protect signal generator determines whether or not the coded image data requires copy protect in accordance with a predetermined identifier included in the coded image data.

6. A computer comprising:

a decoder configured to decode coded image data and output decoded image data in an interlaced form;

a protect signal generator configured to determine if the coded image data requires a copy protect, and produce a copy protect signal when the coded image data requires a copy protect; and

a video graphic controller connected to the decoder and configured to convert the decoded image data to graphic data in a non-interlaced form, supply the graphic data to an internal display and an external display, and prevent the graphic data from being supplied to the external display in response to the copy protect signal.

7. The computer according to claim 6, wherein said video graphic controller is connected to the internal display through a dedicated internal interface and to the external display through an external interface.

8. The computer according to claim 6, wherein said video graphic controller comprises a buffer connected to the internal display and operatively configured to halt in response to the copy protect signal.

9. An image signal control method for a computer system comprising an internal display and external display, the method comprising:

decoding coded image data and outputting the decoded image data in an interlaced form;

determining if the coded image data requires a copy protect;

producing a copy protect signal when the coded image data requires a copy protect;

performing a process on the decoded image data that copy protects the image data in response to the copy protect signal and supplying the copy protected image data to the external display;

converting the decoded image data into graphic data in a non-interlaced form;

supplying said graphic data to the internal display;

supplying said graphic data to the external display if the copy protect signal is not present; and

selecting one of the protected image data and graphic data in response to the copy protect signal and supplying the selected data to the external display.

10. The method of claim 9, wherein converting includes converting the decoded image data into television image data for display on the external display, wherein the converting is halted in response to the copy protect signal.

11. The method of claim 9, wherein converting further includes buffering, wherein the buffering halts in response to the copy protect signal.

12. The method of claim 9, wherein determining if the coded image data requires a copy protect includes reading said data from a disk medium by way of a disk drive loaded in a device bay.

13. The method of claim 12, wherein determining further includes activating a sense switch in response to the loading of a DVD drive into the device bay, wherein said switch indicates that the coded image requires a copy protect.

14. The method of claim 9, wherein determining if the coded image data requires a copy protect is based on a predetermined identifier included in the coded image data.

15. An image signal control method for a computer system comprising an internal display and external display, the method comprising:

decoding coded image data and outputting the decoded image data in an interlaced form;

determining if the coded image data requires a copy protect;

producing a copy protect signal when the coded image data requires a copy protect;

converting the decoded image data into graphic data in a non-interlaced form;

supplying the graphic data to the internal display and external display; and

preventing the graphic data from being supplied to the external display in response to the copy protect signal.

16. The method of claim 15, wherein supplying said graphic data to the internal display and external display and preventing said data from being supplied to the external display in response to the copy protect signal is performed through a dedicated internal interface and an external interface.

17. The method of claim 15, wherein converting includes buffering, wherein the buffering halts in response to the copy protect signal.