JPS62179438A - Digital scanning converter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a digital scan converter used in a sector scan imaging device, a typical example of which is a sector scan ultrasonic diagnostic device.

(Prior Art) In a sector-scan ultrasonic diagnostic device, which is a typical example of a sector-scan imaging device, imaging data obtained along an acoustic scanning line that is sector-scanned is based on the acoustic scanning line in the measurement space. The data is written in a frame memory corresponding to the two-dimensional coordinates, and the data in this frame memory is read out in response to the rask scan of the screen of the image display device and given to the image display device. It performs a conversion between the sector scan of a scan line and the rask scan of an image display device. At that time, due to the nature of sector scanning, the imaging data stored in the frame memory becomes more spaced apart from the data on the adjacent acoustic scanning line as it goes further forward, so if it is displayed as is, in the deep part, the pixels in the direction of the rask scan The density of the image becomes sparse and the quality of the image deteriorates. Therefore, when writing to the frame memory, appropriate data is interpolated between adjacent acoustic scanning lines.

(Problem to be Solved by the Invention) In order to improve the quality of a real-time display image by interpolating imaging data when writing ul into a frame memory, the interpolation means must operate at extremely high speed. However, such interpolation means are generally expensive. Therefore, digital scan converters using such interpolation means are expensive.

The present invention has been made in view of these problems, and its purpose is to create a quality difference between a real-time image and a still image, and to use an interpolation means that does not require very high-speed operation. An object of the present invention is to provide a digital scan converter with reduced cost.

(Means for Solving the Problems) The present invention, which solves the above problems, provides a frame memory that stores imaging data generated by a sector scan imaging data generation means in addresses corresponding to two-dimensional coordinates of a space to be measured. , the operation is enabled in the still image display mode, and interpolation means performs higher-order interpolation than primary interpolation on data in the frame memory in the direction of sector scan; A frame memory reading means that reads data in accordance with the scanning of the two-dimensional display surface, and substantially zero-order interpolation of the data read by the frame memory reading means in the scanning direction of the two-dimensional display surface of the image display device. The apparatus is equipped with an output means for outputting the data as display data.

(Function) The interpolation circuit performs first-order or higher-order interpolation only when displaying a still image, and only O-order interpolation is performed by the output means when displaying a real-time image.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

An embodiment of the invention is shown in FIG. In FIG. 1, reference numeral 1 denotes a sector scan imaging data generation circuit, which in a sector scan ultrasonic diagnostic apparatus, for example, corresponds to a portion that generates received data for each acoustic scan line.

Reference numeral 2 denotes a frame memory that stores output data of the sector scan/imaging data generator 1 at an address specified by the write address generator 3. The captured address generator 3 generates, for each data on a scanning line subjected to sector scanning, an address corresponding to the two-dimensional coordinates of the data in the measured space. Write address generator 3 is controlled by control circuit 4 .

The data in the frame memory 2 is read out according to the address given by the read address generator 5 and given to the image display device 7 through the output circuit 6. The read address generator 5 performs read addressing in accordance with the display method of the image display device 7,
If the image display device 7 is, for example, a CRT display using a rask scan method, a read address corresponding to the rask scan is generated. Read address generator 5 too! It is controlled by the ljJ control circuit 4.

The output circuit 6 outputs the read data from the frame memory 2 while interpolating the data gap caused by the opening of the sector scan scanning line, and for example,
A zero-order interpolation circuit is suitable, which interpolates the same data as the previously read data until the next new data is read. Such an O-order interpolation circuit can also be called a data expansion circuit. Such an output circuit has a simple function and can be constructed at low cost.

Since the output circuit 6 performs O-order interpolation or data enlargement in the direction of the rask scan, the image displayed on the display device 7 does not have a sparse N degree of pixels even in deep parts. However, since the interpolation method is easy, the quality of the image is also comparable.
As a real-time image, this is acceptable in terms of cost.

High quality images are required rather in still images. Therefore, an interpolation circuit 8 that performs first-order or higher-order interpolation is provided, and the interpolation circuit 8 performs interpolation for image data to be displayed in a stationary state. When the image display device 7 is switched to the still image display mode under the control of the control circuit 4, the interpolation circuit 8 interpolates data stored in the frame memory 2 into gaps between sector scan lines. Performs interpolation calculations. Since interpolation calculations are performed on data for still images, high speed is not required unlike data for real-time display.

Therefore, even if the interpolation circuit 8 is a first-order or higher-order interpolation circuit, it can be constructed relatively inexpensively.

The interpolation circuit 8 may be provided on the input side of the frame memory 2 as shown in FIG. In Figure 2,
The write data input and write address input of the frame memory 2 are switched by switching circuits 9 and 10, respectively. The switching circuits 9 and 10 are controlled by the control circuit 4 to always select the write data from the sector scan imaging data generator 1 and the write address from the programmable address generator 3 during real-time imaging. However, when displaying a still image, control is performed to select the m write data and write address given from the interpolation circuit 8. In this case, the sector scan/imaging data generator 1 performs sector scan for each frame at a speed lower than that in real time so that the interpolation circuit 8 can operate in time based on the still image display notice signal, etc. shall be done for the same amount. Since the image to be displayed is a still image, there is often no problem even if the sector scan speed is reduced by one frame.

(Effects of the Invention) As explained above, according to the present invention, a difference in quality is created between a real-time image and a still image, and costs are reduced by using an interpolation means that does not require very high-speed operation. A reduced-sized digital scan converter can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of another embodiment of the invention. 1... Sector scan/imaging data generator 2... Frame memory 3... Write address generator 4... Control circuit 5... Read address generator 6... Output circuit 7... Image Display device 8...Interpolation circuit 9.10...Switching circuit

Claims (1)

[Claims] A frame memory that stores the imaging data generated by the sector scan/imaging data generation means at an address corresponding to the two-dimensional coordinates of the measured space.The operation is enabled in the still image display mode, and the data in the frame memory is sector scanned. interpolation means that performs higher-order interpolation than primary interpolation in the direction of A digital scan converter comprising output means for performing substantially zero-order interpolation in the scanning direction of a two-dimensional display surface of an image display device on the data read by the means and outputting the resultant resultant as display data.