1. A video display apparatus which displays a video image based on a video signal using a fixed-pixel type device, comprising
a contrast adjusting unit to adjust the contrast of the video image by controlling the gain of the video signal based on a maximum luminance level information and an average luminance level information of the video signal; and
a black level extension unit to perform black level extension processing for the video signal,
wherein the black level extension unit is configured to decrease an output luminance level corresponding to an input luminance level which is equal to or lower than a starting level set for the video signal in the case where the contrast is adjusted to increase by the contrast adjusting unit.
2. The video display apparatus according to claim 1, wherein the contrast adjusting unit is configured to adjust the contrast of the video image by controlling the gain of an analog video signal or the gain of a digital video signal.
3. The video display apparatus according to claim 1, wherein the fixed-pixel type device is a plasma display panel or a liquid crystal panel.
4. The video display apparatus according to claim 1, wherein the maximum luminance level information and the average luminance level information are detected for a period of one frame or one field of the video image.
5. The video display apparatus according to claim 1, wherein the black level extension unit performs the black level extension processing based on the average luminance level information of the video signal.
6. The video display apparatus according to claim 5, wherein the black level extension unit is configured to perform the black level extension processing so that the higher the average luminance level information is, the larger the decreasing amount of the output luminance level is.
7. The video display apparatus according to claim 5, wherein the black level extension unit is so configured as not to perform the black level extension processing if the average luminance level information is equal to or lower than a set value, and to perform the black level extension processing if the average luminance level information is equal to or larger than the set value.
8. The video display apparatus according to claim 7, wherein the black level extension unit is configured so that the unit performs the black level extension processing based on the characteristic of the decreasing amount corresponding to the average luminance level information and that the characteristic of the decreasing amount in the case, where the average luminance level information falls within a second luminance region which is larger than a first luminance region, that is, a region between the set value and a prescribed value, is smaller than the characteristic of the decreasing amount in the case where the average luminance level information falls within the first luminance region.
9. The video display apparatus according to claim 1, wherein the black level extension processing is performed by the black level extension unit after the contrast is adjusted by the contrast adjusting unit.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A device for protection against unauthorized removal of a trailer, the trailer having a first electronic brake system and a second brake system, the device comprising:
an operator controller configured to protect against the unauthorized removal of the trailer by at least one of activating and deactivating a first protection component that comprises service brakes of the second brake system and a second protection component that comprises a spring-actuated brake of the second brake system; and
a control element coupled to (i) the first electronic brake system, (ii) a parking brake valve of the second brake system, and (iii) an overload protection valve of the second brake system via a connecting line, wherein the operator controller is configured to activate the first protection component by controlling the first electronic brake system to activate the service brakes, wherein the operator controller is configured to activate the second protection component by controlling the control element via the first electronic brake system to vent the connecting line such that the spring-actuated brake is engaged, and wherein the operator controller is configured to receive at least one of a first coded numerical value and authentication information to activate and deactivate the first and second protection components.
2. The device of claim 1, wherein the control element is shiftable from a first stable operating condition to a second stable operating condition by at least one of a single current and voltage pulse.
3. The device of claim 1, wherein when any one of the first and second protection components is activated, the trailer is braked with a metered braking action, the metered braking action being smaller than a maximum braking action, such that the trailer is not fully stopped.
4. The device of claim 3, wherein the metered braking action is controlled to prevent the trailer from exceeding a predetermined speed.
5. The device of claim 3, wherein the metered braking action is effected by one of the spring-actuated brake and the service brakes.
6. The device of claim 4, wherein when the predetermined speed is exceeded, a signal is presented at a predefined signal output of the trailer.
7. The device of claim 1, wherein the authentication information is obtainable from one of a magnetic card and a chip card.
8. The device of claim 1, wherein activation and deactivation of the first and second protection components is performed externally on the trailer.
9. The device of claim 1, wherein the operator controller (i) activates at least one of the first and second protection components at least one of automatically and manually, and (ii) deactivates at least one of the first and second protection components in response to receiving a radio signal.
10. The device of claim 1, wherein the operator controller activates and deactivates at least one of the first and second protection components in response to receiving a radio signal.
11. The device of claim 1, wherein at least one of the first and second protection components is activatable and deactivatable by a tractor coupled to the trailer, the tractor being configured to activate and deactivate the at least one of the first and second protection components via a controller-area network interface.
12. The device of claim 9, wherein the radio signal is a Short Message Service.
13. The device of claim 10, wherein the radio signal is a Short Message Service.
14. The device of claim 1, wherein the control element comprises a bistable current surge valve.
15. The device of claim 1, wherein the control element is configured to vent the connecting line by occupying a first of two stable operating conditions, and wherein the control element is configured to remain in the first stable operating condition even after a power supply is disconnected from the control element.