JPS5964029A - Window control apparatus for image display - 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 The present invention relates to an image display window control device used in a tomographic imaging apparatus (hereinafter simply referred to as a CT rack) using a converter, and in particular to a window control device for setting the window center level and window width. The present invention relates to an improvement of a variable image display window control device.

As shown in FIG. 1, images reconstructed by an OT device generally have an X-ray absorption coefficient (CT value) of water of "0" and an X-ray absorption coefficient of air of "1-1000".

The X-ray absorption coefficient of bone is expressed as -1-1000j.

Here, if X-ray absorption coefficients from -1000 to +1000 are actually displayed on a cathode ray tube (CRT), fine differences in X-ray absorption coefficients cannot be distinguished. Therefore, a window mechanism is used to enlarge and display a portion of the image, for example, an X-ray absorption coefficient of 0 to 100, and fine differences in X-ray absorption coefficients are observed in black and white. At this time, if it is desired to change the displayed portion of the X-ray absorption coefficient to be enlarged, it is necessary to be able to independently vary the setting of the window center level and window width for enlarged display.

FIGS. 2(A-) and 2(B) are diagrams showing a conventional example of an image display window control device in which the window center level and window width settings are variable.

In the conventional example shown in FIG. 2(A), two levers, a window center level setting lever LBVT and a window width setting lever WIDTI-1, are provided on the operation panel. When the lever LEVEL is manually moved and held upward, the window center level gradually rises, and when it is moved and held downward, the window center level gradually falls. It's Kade.
When the lever WIDTI is moved and held upward,
The window width gradually increases, and if you move and hold it downward, the window width gradually decreases.

Here, the lever LEVEL and WIDTT-
The number of control pulses increases and decreases in accordance with the movement and holding time of 1, and the window center level and window width are controlled by this number of control pulses.

The conventional example shown in FIG. 2 (13) uses a dial system instead of the one-lever system, and the direction of vertical movement of the window center level and the expansion or contraction of the window width are determined by the rotation direction of the dial. It is something that The amount of change in the window center level and window width is controlled by the number of control pulses depending on the rotation angle of the dial.

In such conventional image display devices, large adjustments when the amount of change in the window center level and window width are large, and fine adjustments when the amount of change is small conflict with each other. The drawbacks were that it took too much time to set the center level and window width, and the operability was poor.

It is an object of the present invention to eliminate the drawbacks of the prior art, to provide a rotary plate having one or a plurality of slots arranged at regular intervals in the radial direction, and to rotate the slots and torsions. Equipped with a means to set the amount of change according to the rotation speed of the plate,
To provide an image display window control device in which a rotary plate is rotated quickly when a large amount of change is desired, and rotated slowly when a small amount of change is desired.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 3 is a sectional view showing the control pulse signal generation mechanism of this embodiment, and FIG. 4 is a plan view of the pickpocket and rotating plate of FIG. 3.

In the figure, 1 is the panel of the operation panel, 2 is the window control dial, 6 is the rotating shaft of the window control dial 2, and 4 is the slotted rotating plate. A plurality of slots 4A are provided on the periphery. This rotary plate 4 is attached to a rotary shaft 6 of the window control dial 2, and the rotary shaft 3 is rotatably supported by a support member 5. Reference numeral 6 denotes a pick-pocket detector using light, which converts pick-pockets and pick-ups into pulse signals.

FIG. 5 is a configuration diagram of the window control circuit of this embodiment, in which 7 is a counter for counting the number of sets of pulse signals from the pick-and-drop detector 6 of FIG. 3, and 8 is a counter for latching the output of the counter 7. , child circuit 9 is a nonlinear circuit for increasing the number of set window levels, and uses, for example, a squaring circuit consisting of a multiplier.

+oB computer read gate circuit; 11 is a control circuit that controls each of the circuits described above;

FIG. 6 is a diagram for explaining the operation of this embodiment,
(a) is a counter reset signal, (h) crawl, chi signal,
(c) is a nonlinear circuit calculation output signal, and (d) is a combinatorial gate signal.

Next, the operation of this embodiment will be explained.

When the window control dial 2 is rotated to the right,
The rotating plate 4 rotates. The amount of rotation of this slit rotary plate 4 is the same as that of 4A.

The number of pulses is detected by the pulse detector 6 and output as a pulse signal. The pulse signals from the pick-up and pick-up detectors 6 are input to the counter 7;
The pulse signal is input after the count number is reset to zero by the counter reset signal (a) from the control circuit 11. The pulse signal is input to a counter 7 and counted for a certain period of time T1, for example, 02 seconds. This counted value is calculated as follows:
) is transferred to the next stage, the child circuit 8, and the counter 7 is reset by the counter reset signal (a) to start the next count. The output of the circuit 8 is input to the non-linear circuit 9 and divided.

After this calculation, the computer read gate circuit (d) reads the calculated value to the computer CPU, and changes the window center level and window width of the window display.

Here, when the window control dial 2 is rotated quickly, a large number of slots IJ, ) 4 A provided on the pickpocket rotary plate 4 are detected during a certain period of time, and when the window control dial 2 is rotated slowly. Will be detected as a pickpocket.

) 4A, the window control dial 2 is rotated quickly for adjustment with a large amount of change, and rotated slowly for fine adjustment with a small amount of change. Furthermore, the reason why the number of slits detected is increased by the non-linear circuit 9 is to expand the number of set window levels and to speed up the operation when the amount of change is large.

FIG. 7 shows the relationship between the window control dial rotation speed and the number of computer read pulses.

It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without changing the gist thereof. For example, although a square circuit is used as the non-linear circuit, it is also possible to use a circuit multiplied by n, such as a 15th power, a cube, etc., and obtain the numerical value by experiment. Further, all functions of the control circuit shown in FIG. 5 may be performed by a computer.

As explained above, according to the present invention, it is possible to rotate a slit rotary plate having one or more slits and grooves in the radial direction, and set the amount of change according to the rotational speed of the slit and groove rotary plate. This makes it possible to control the amount of change due to the rotation speed of the window control dial, and to
It can be changed not only at high speeds but also continuously in response to rotational speeds of 1 degree. As a result, the window center level and window width can be freely set, and the setting time can also be shortened. Moreover, operability can also be improved.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the window function, and Figs. 2 (A) and (B) are diagrams showing a conventional example of a window control device for image display in which the window center level and window width settings are variable. , FIG. 3 is a cross-sectional view showing a control pulse signal generation mechanism according to an embodiment of the present invention, FIG. 4 is a plan view of the pickpocket rotary plate shown in FIG. 3, and FIG. FIG. 6 is a diagram for explaining the operation of the embodiment shown in FIGS. 3 to 5. FIG. 7 is a diagram showing the window control dial rotation speed and the heater. FIG. 3 is a diagram showing the relationship between the number of read pulses. In the figure, 1 operation panel panel, 2 window control dial, 6 window control dial rotation axis, 4 slot, rotating plate, 5 support member, 6 slot detector, 7
8 a latch circuit, 9 a nonlinear circuit, 10 a computer read gate circuit, and 11 a control circuit. Agent Patent Attorney Autumn 1) Collection Figure 1 (Air) Figure 2 (A) (El)

Claims (1)

[Claims] In an image display window control device having means for controlling a window center level and window width, a slit or a plurality of slits are provided in the radial direction for setting the window center level and window width; a rotating plate; a slit detector that uses light to detect slits on the rotating plate and convert them into electrical signals; and sampling the output of the slit detector at a fixed time; A sample and hold circuit that holds it,
An image display window control device comprising a non-linear circuit that converts the output of the sample-and-hold circuit into a non-linear output.