Radar device and the like
DCFirst Claim
1. Radar and like apparatus comprising:
- a current-image video memory for storing most recently received data;
a past-image video memory for accumulatively storing previously received data;
an indicator for superimposing and displaying the data stored in both the current-image video memory and the past-image video memory; and
a controller for transferring the data stored in the past-image video memory to a buffer in a first step and re-transferring the data stored in the buffer back to the past-image video memory in a second step when display range scale has been changed, wherein address shift data K specifying the amount of address shift per transfer cycle in the buffer and the past-image video memory for said data transfer and re-transfer processes is changed in accordance with the range scale.
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Accused Products
Abstract
When the range scale has been changed, past target images which have been stored are converted to fit to a new range scale such that the past target images can be displayed in continuity on the new range scale without erasing the previously stored past target images. When the range scale is switched by operating a range selector 24, a controller 23 sets the amount of address shift K2 for a current-image video memory 20 and the amount of address shift K1 for a past-image video memory 21. Data in the past-image video memory 21 are successively read out according to K1 and transferred to the current-image video memory 20 in a first step. During this step, access address of the memory 20 is advanced according to K2. In a second step, the data stored in the current-image video memory 20 is re-transferred back to the past-image video memory 21 according to the re-set amounts of address shift K1 and K2. Upon completion of data transfer of the first step and data re-transfer of the second step, normal operation is resumed on the new range scale.
13 Citations
6 Claims
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1. Radar and like apparatus comprising:
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a current-image video memory for storing most recently received data;
a past-image video memory for accumulatively storing previously received data;
an indicator for superimposing and displaying the data stored in both the current-image video memory and the past-image video memory; and
a controller for transferring the data stored in the past-image video memory to a buffer in a first step and re-transferring the data stored in the buffer back to the past-image video memory in a second step when display range scale has been changed, wherein address shift data K specifying the amount of address shift per transfer cycle in the buffer and the past-image video memory for said data transfer and re-transfer processes is changed in accordance with the range scale. - View Dependent Claims (2, 3, 4, 5)
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6. Radar and like apparatus comprising:
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a current-image video memory for storing most recently received data;
a past-image video memory for accumulatively storing previously received data;
an indicator for superimposing and displaying the data stored in both the current-image video memory and the past-image video memory;
stored data transfer means for transferring the data stored in the past-image video memory to the current-image video memory in a first step and re-transferring the data stored in the current-image video memory back to the past-image video memory in a second step when display range scale has been changed;
shift data setting means for changing address shift data K specifying the amount of address shift per transfer cycle in the current-image video memory and the past-image video memory for said data transfer and re-transfer processes in accordance with the range scale;
first access detecting means for judging whether each pixel of the video memory used as a transfer destination is at a first-accessed address when executing a scale-down operation in which the address shift data K for the transfer destination is smaller than the address shift data K for a transfer source; and
means for transferring data stored in the transfer source video memory to an address of the transfer destination video memory if the first access detecting means judges that said address is first accessed, and writing the data stored in the transfer source video memory or data previously stored in said address of the transfer destination video memory, whichever having a larger value, based on a comparison of these data if said address is not first accessed.
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Specification