Night vision system and control method thereof
First Claim
1. A night vision system, comprising:
- a device that emits electro-magnetic radiation towards a subject;
a camera that captures an image of the subject illuminated by the device;
a display, operably connected to the camera, that displays a captured image; and
a controller that is operably connected to and controls operation of the device, the camera and the display, the controller including a second circuit, a first circuit, a gamma adjuster and a gamma amplifier, wherein the controller;
receives a brightness signals, constituting an image signal indicative of an image to be displayed on the display from the second circuit;
produces a gamma correction signal from the brightness signal based on a brightness ratio characteristic via the gamma adjuster in which a display brightness is set to a maximum brightness using a first brightness correction ratio when a signal level of the brightness signal is a maximum signal level, and the display brightness is set using a second brightness correction ratio which is lower than the first brightness correction ratio when the signal level of the brightness signal is lower than the maximum signal level; and
outputs the produced gamma correction signal to the display via the gamma amplifier.
1 Assignment
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Accused Products
Abstract
A second circuit separately extracts a synchronization signal and brightness signal from an image signal output from a camera for capturing an image of a subject. A gamma amplifier produces a gamma correction signal based on a brightness ratio characteristic in which a display brightness increases as the signal level of the brightness signal increases and the display brightness is set using a display brightness correction ratio which is preferably 70 to 90% of an equi-proportional display brightness correction ratio when the signal level of the brightness signal falls in a high-brightness range. A liquid crystal display receives the gamma correction signal and displays an image captured by the camera with the display brightness set in accordance with the brightness ratio characteristic while synchronizing with a drive timing signal output from a first circuit. Thus, the difference in display brightness between different high-brightness regions or subjects is made large, whereby halation which may otherwise occur between those regions or subjects can be prevented.
6 Citations
19 Claims
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1. A night vision system, comprising:
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a device that emits electro-magnetic radiation towards a subject;
a camera that captures an image of the subject illuminated by the device;
a display, operably connected to the camera, that displays a captured image; and
a controller that is operably connected to and controls operation of the device, the camera and the display, the controller including a second circuit, a first circuit, a gamma adjuster and a gamma amplifier, wherein the controller;
receives a brightness signals, constituting an image signal indicative of an image to be displayed on the display from the second circuit;
produces a gamma correction signal from the brightness signal based on a brightness ratio characteristic via the gamma adjuster in which a display brightness is set to a maximum brightness using a first brightness correction ratio when a signal level of the brightness signal is a maximum signal level, and the display brightness is set using a second brightness correction ratio which is lower than the first brightness correction ratio when the signal level of the brightness signal is lower than the maximum signal level; and
outputs the produced gamma correction signal to the display via the gamma amplifier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 19)
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11. A control method for a night vision system, comprising:
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emitting electro-magnetic radiation toward a subject;
capturing an image including the electro-magnetic radiation reflected by the subject with a camera;
outputting an image signal from the camera to a controller comprising a second circuit, a first circuit, a gamma amplifier and a gamma adjuster;
inputting the image signal to the second circuit;
receiving a brightness signal constituting a portion of the image signal indicative of an image to be displayed on a display;
setting a display brightness to a maximum brightness using an equi-proportional display brightness correction ratio when a signal level of the brightness signal is a maximum signal level; and
setting a display brightness using a display brightness correction ratio that is lower than the equi-proportional display brightness correction ratio when the signal level of the brightness signal is lower than the maximum signal level. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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Specification