JPH0245905Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention can be used in the field of nuclear medicine, for example, to display images from a scintillation camera, or in other fields. The present invention relates to an image display device having an afterglow function (persistence function) used for.

(B) Prior Art Conventionally, a persistence scope has been used as an image display device having this afterglow function. However, this persistence scope has the disadvantage that it is very expensive because it is constructed using a special cathode ray tube.

(C) Purpose In view of the above, the present invention aims to provide an image display device that uses an ordinary cathode ray tube and has an afterglow function at low cost by using an electronic circuit without using a special cathode ray tube. purpose.

(d) Configuration The image display device according to this invention counts this signal for each position when a signal to display a dot at a certain position is input, and displays a dot on a cathode ray tube with a brightness proportional to the number of counts. In addition to displaying it on the screen, the above-mentioned count number is subtracted by a predetermined number every certain number of display frames to gradually reduce the brightness to create an afterglow effect, and a proportional coefficient between the count number and the brightness. Also, the reduction ratio of the count number to the number of display frames can be arbitrarily set.

(E) Embodiment In the figure, a memory circuit 1 has one-to-one addressing for position signals (X, Y signals) input from a scintillation camera, etc. Every time an unblank signal (dot display signal) is input to the adder circuit 2 and informs that the position signal has been inputted to the adder circuit 2, the address specified by the position signal is read out and added. The circuit 2 adds this read information "1" (or N, N is an arbitrary natural number), and the signal to which "1" (or N) has been added is written again to the same address. This means that the number of unblank signals input for each position specified by the position signal is counted. The count number stored in each address of this memory circuit 1 is read out and sent as a luminance signal to the cathode ray tube 4 via the multiplication circuit 3, and the count number is placed at a position specified by the deflection signal from the display scanning circuit 5. A dot with the corresponding brightness is displayed. A display scanning circuit 5 is provided so that the readout scan of the memory circuit 1 and the display scan of the cathode ray tube 4 are synchronized.
A read scanning signal is applied to the memory circuit 1 from the memory circuit 1. On the other hand, the signal read from each address is sent to the subtraction circuit 6, and is subtracted by "1" (or N) every time it is read out, that is, every time one frame is displayed, or Every time it is read n times (n is any natural number), that is, every n frames, it is subtracted by "1" (or N) and written to the same address. The number n of frames and the multiplication coefficient to be multiplied by the multiplication circuit 3 are given by the control circuit 7, and these can be set arbitrarily. Note that instead of subtracting, a coefficient less than "1" may be multiplied.

Therefore, according to the configuration of this embodiment, the brightness (Growth) for the same count number can be adjusted arbitrarily by setting the multiplication coefficient arbitrarily by the control circuit 7, and the brightness (Growth) can be adjusted arbitrarily by setting the number of frames n. Does the brightness remain for a long time (Persistence)?
can be adjusted. When dot display signals at a certain position are input one after another, they are counted and accumulated, and a dot is displayed with a brightness proportional to the count number using the set Growth as a proportional coefficient, and when there is no input, the dots are displayed according to the set Persistence. A display is made in which the brightness of the dot gradually decreases as time passes.

(f) Effects According to this invention, the same function as a persistence scope is achieved using an electronic circuit, so a cathode ray tube can be used in general, and there is no need to use a special cathode ray tube, so it is inexpensive and Maintenance is easier, and the cathode ray tube is less likely to burn out than traditional persistence scopes. Furthermore, the adjustment range for Growth and Persistence can be wider than traditional persistence scopes.

[Brief explanation of the drawing]

The figure is a block diagram of one embodiment of this invention. 1... Memory circuit, 2... Addition circuit, 3... Multiplication circuit, 4... Braun tube, 5... Display scanning circuit,
6... Subtraction circuit, 7... Control circuit.

Claims (1)

[Scope of utility model registration request] A storage means having an address corresponding to each position where a dot is to be displayed, and an adding means which adds the contents of the address corresponding to a certain position by a fixed number when a dot display signal for displaying a dot at a certain position is input. and a multiplication means for multiplying the signals read from each address of the storage means by a predetermined coefficient; and a multiplication means for multiplying the signals read from each address of the storage means by a predetermined coefficient, and sequentially placing dots of brightness corresponding to the signals successively outputted from the multiplication means at different positions on the display screen of the cathode ray tube. display means for performing display scanning so as to display the image; reading means for performing readout scanning of the memory circuit in accordance with the display scanning; 1. An image display device comprising: a subtracting means for storing data in the multiplication coefficient; and a control means capable of arbitrarily changing the reduction ratio with respect to the multiplication coefficient and the number of readout scans.