JP3028603B2 - Multi-line type radiographic imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is to move a detector array in which a plurality of radiation element arrays in which a plurality of radiation element elements are arranged one-dimensionally are arranged in a predetermined direction while moving in a predetermined direction. The present invention relates to a so-called multi-line sensor type radiation image capturing apparatus that captures a two-dimensional radiation image by collecting data of the output of an element based on a photon counting method.

<Prior Art> In the above-described multi-line sensor type radiation image capturing apparatus, conventionally, the step movement direction of the detection element row is a direction orthogonal to the row, and the movement amount of one step is:
The same as the length of the detector in the direction of its movement,
Corresponding to each detection element row, counter rows consisting of the same number of counters as the number of elements in the row are provided in the same number as the detection element rows, and each is individually connected to the detection element row and the output from each element is output. Is configured to count.

And the count data by each counter row is
At the end of each stepwise movement of the detector array, all of them are transferred to the memory of the data processing device before the next step is started, and the contents of each counter are reset before proceeding to the next measurement step. It is configured to be.

<Problem to be Solved by the Invention> When all data counted by each counter row is transferred after one-step measurement is completed as in the above-described conventional apparatus, the number of detection elements is proportional to the number of detection elements. As a result, the transfer time and the time required for writing to the memory increase. Until the data is transferred and written to the memory, the next measurement step cannot be performed, so that an increase in these times leads to an increase in the measurement time.

In such a conventional imaging device, the spatial resolution is such that the length of the detecting element in the moving direction (longitudinal dimension) in the moving direction, and the length of the element in that direction in the direction perpendicular to the moving direction (longitudinal dimension). Lateral dimension) is the limit.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the two-dimensional resolution by improving the spatial resolution over the detection element size and reducing the effect of the time required for data transfer from the counter train and writing to the memory on the entire measurement time. It is an object of the present invention to provide a multi-line sensor type radiation image measuring apparatus having a high spatial resolution and a short measuring time.

<Means for Solving the Problems> A configuration for achieving the above object will be described with reference to FIG. 1 corresponding to the embodiment. In the present invention, as shown in the front view of FIG. The sensitive surface of each detection element s ‥‥ s is made rectangular, and the detector array 1
検 出 s is moved in the diagonal direction, and the movement amount of one step is 1 / m of the length 1 of the diagonal of each detection element s ‥‥ s.
(M is an integer), and as shown in the side view and the circuit configuration diagram in FIG. 3 (b), n detection element rows S ₁ , S ₂ ,.
· · S m × relative _{n (n} + 1) columns of the counter column C _{1, 1,} C
_1,2 , C _2,1 , C _2,2 ,..., C _{n + 1, m} are provided, and each detecting element row S ₁ , S ₂ ,.
Counter column C _{1, 1} for inputting the output data of the _{S n, C 1,2, C 2,1} ,
_.. Cn _{+ 1, m} are sequentially switched, and the counter row in which the input is not performed is configured to either hold count data or transfer data to the data processing device 4. ing.

<Operation> m sets of counter rows always correspond to each detection element row, data is input to any one of these sets at each step, and the other data is kept in a data holding state. Since there are m × (n + 1) counter columns, m sets of counter columns always remain. By transferring the count content of the counter row in the remaining state to the data processing device 5, data can be transferred for a predetermined counter row while another count row is counting, in other words, during measurement.

As for the resolution, the detector is moved stepwise in the diagonal direction length direction by 1 / m of the diagonal length l as shown in FIG. 5 so as to be orthogonal to the element row direction as exemplified in FIG. The length of the element s in each direction is divided into 1 / m, in other words, the area of one element S is divided into m ² . Then, this is counted by m counters for each step. By deconvolving the count contents of each counter, the area of the element s is reduced.
A spatial resolution of 1 / m ² is obtained.

<Embodiments> FIGS. 1A and 1B are configuration diagrams of an embodiment of the present invention. FIG. 1A is a front view of the detector array 1 as viewed from a sensing surface side, and FIG. For, there are a plurality of elements or counters in a direction orthogonal to the paper surface.

The detector array 1 is composed of three detection element rows S ₁ , S ₂ and S ₃ , and each detection element s ‥‥ s has a square sensing surface of the same size.

Further, all the elements s ‥‥ s in each element row are connected to a signal processing circuit 11 such as a charge amplifier, respectively.
The output signal of の s is converted into a pulse signal of a logic level and output. Then, the detector array 1 is driven by a driving device (not shown) in the diagonal direction of each detection element s ‥‥ s, with the diagonal length l of the element.
The displacement is given in steps of 1/2 distance.

An output signal for each element from the detector array 1 is input to a counter of a corresponding row of any counter column in the counter column group 3 through a gate of a corresponding row in the gate column group 2A, 2B. Is done.

Counter array groups 3, 2 × (3 + 1) = eight columns counter column _{C 1,1, C 1,2, C 2,1} , C 2,2, constituted by · · · C _{4, 2,} each counter The number of counters in a row is equal to the number of elements in each detection element row.

Each counter in the counter row group 3 is given an operation instruction such as input data counting, count data transfer, or reset by a control signal from the control circuit 5, and the transferred count data is subjected to data processing. Incorporated into device 4.

Each of the gate row groups 2A and 2B is a circuit having half the number of gate rows of the counter row, and the counter rows C _1,1 , C _1,2
Is connected to the gate row G _B1 , C _2,1 , C _2,2 is connected to the gate row G _B2 , and the ‥‥ counter row C _4,1 , C _4,2 is connected to the gate row GB ₄ . Also, the gate rows G _B1 , G _B2 , ‥‥ G of the gate row group 2B
_B4 is the gate row G _A1 , G _A2 , ‥‥ G _{A4 of the} gate row group 2A, respectively.
It is connected to the.

The outputs from the detection element arrays S ₁ , S _2, and S ₃ are both introduced into each of the gate arrays in each of the gate array groups 2 A and 2 B, and the detector array 1 is controlled by a command from the control circuit 5. moved in synchronism with the steps, detecting element arrays S _1, S ₂
And switching the counter column for introducing the output of the S _3.

In FIG. FIG. 2 showing the gate array group 2A, the gate array G _Ai in 2B, G _Bi and each counter column C _i, a specific configuration of _j, gate array G _Ai
In each gate, the output from the element in the corresponding row of the detection element columns S ₁ , S ₂ and S ₃ is introduced, and one of three inputs is provided by a gate signal supplied from the control circuit 5. Is selectively introduced into the counter of the corresponding row in the counter column C _{i, j} . Note that the same selection is made for all counters in the same column.

The control circuit 5 supplies the gate signals to the gate row groups 2A and 2B as described above, and counts the input signal, transfers the count data, holds the data, or counts each of the counters in the counter row group 3. An operation command for resetting the contents is given, and the control of each counter row by the control circuit 5 is summarized in Tables 1 and 2 on the next page.

In each of these tables, mode A is a mode for selecting i of the counter train represented by C _{i, j} , and is used for the gate signal of the gate train G _Ai , and mode B is a mode for selecting j similarly, Used as G _Bi gate signal. Mode B consists of 0 and 1 and advances by one for each step. The mode A is composed of 0, 1, 2, and 3, and increases by one each time the mode B becomes 0. Further, in the table, the count indicates an operation of counting data from the detection element row, the transfer indicates transfer of count data to the data processing device 4, and the reset further indicates that the transfer is performed before the count operation is started. Means to reset the count contents.

To explain by taking the example, for example, in mode A = 0, Datosuruto mode B = 0 at this time, the data row of detecting elements S ₁ is introduced into the counter column C _{1, 1.}

FIG. 3 shows a configuration example of the control circuit 5 for performing the above control. In this example, five counters 51-55,
Each control signal is obtained with the lapse of time by using two decoders 58 and 59 and using a clock signal.

Here, the clock signal from the clock oscillator 56 is adjusted by the programmable frequency divider 57 so that the data transfer time of one counter row (the time when the counters 51 and 52 become full) and the measurement time become equal. Note that counters 51 and 52
Goes to full scale in one step.

The output of the counter 51 and the output of the decoder 58 specify the row number and address of the counter for transferring data. Further, a signal indicating the number of transfer (measurement) steps is obtained from the output of the counter 53, and a mode B signal is obtained from the output of the counter 54. The output of the counter 55, which counts up by one according to the carry signal of the counter 54, is passed through the decoder 59 to obtain the mode A signal.

Next, what data is transferred from each counter row by the above operation will be described.

FIG. 4 is a conceptual explanatory view of the relationship between the vertical component of the movement of the detector array 1 and the counter row 3, and FIGS.
(F) shows the order of the steps in order of time, and shows a counter sequence C1 _{, j} as an example. Further, in this example, X within the range of the size of the detection element around the point α is used.
A line (hereinafter, referred to as an X-ray in an α region) and an X-ray (hereinafter, referred to as an X-ray in a β region) centered on the β point and within the size of the detection element are detected by a detection element array. The process of counting is shown. The α point and the β point are separated by 1/2 of the vertical length of the detection element, and the α region and the β region are 1/1 of the respective regions.
Two overlaps. _{Incidentally, s 1, s 2, s} 3 in FIG.
Represents a detection element of a predetermined row in each row of detecting elements _{S 1, S 2, S 3} , the counter c _1,1, c _1,2 are counter column C _{1, 1,} of a predetermined row in the C _{1, 2} Shows a counter.

FIG. 5 is an explanatory diagram showing the detector array 1 as viewed from the front.
In the diagonal direction, the relationship between the sensing surface of each detection element s ‥‥ s and the X-ray is two-dimensionally as shown in FIG. This two-dimensional description will be made after the description focusing on only the vertical component shown in FIG.

Now, in the first FIG. 4 (a), X-ray of the α region is measured by the detection element s _3. At this time, the output signal of the detection element is processed into a pulse signal, which is counted by the counter _c1,1 .

Next, as shown in (b), the detection element row moves by 1/2 in the diagonal direction by one step. At this time, if attention is paid only to the vertical component, the X-rays in the α region are detected by the detection element s ₃
Because it irradiated to the lower half of the upper half and the detection element s _2, and can not be extracted as the sole signal. Instead, the detector
In s ₃ can detect X-rays of the β region. This signal is counted by the counters c ₁ , ₂ . During that time, the counter c _1,1 is made to play while holding the data.

Next, as shown in (c), when the detection element row moves by one more step, this time, for the same reason, X
Can no longer be measured by the line single detector elements, X-rays of the α region can be detected solely by the detecting element s _2. Here changing connecting the output signal of the detector element s ₂ in the counter c _{1, 1,} is added to the top of the previous data. During this time, the counters c _{1, 2} are made to play while holding the data. Figures (d), (e), (f)
Indicates a state in which the detection element row sequentially moves down one step at a time in the same manner. If there is a detection element capable of independently detecting X-rays in the α region as described above, the signal from the detection element is counted by a counter c. ₁ , and the counters c ₁ , ₂ are left idle in the data holding state. The same applies to X-rays in the β region. Then, when the state of the step position which is also not incident X-rays of the X-ray also β region of α region, ie If a next step position state in FIG. (F), the counter c _{1, 1,} of c _{1, 2} Transfer the contents to memory.

By the way, actually, it is necessary to consider the horizontal component as well as the above. That is, as shown in FIG. 5 (a), the α region and the β region are considered to be regions in which one half of each side overlaps each other. Then, since each detection element having the same sensitive surface area as each of these regions moves by l / 2 in the diagonal direction, the information in the region divided into 1/2 of each side in the horizontal direction as described above. Is obtained, and by combining the outputs from the detection elements for two rows, each region is sampled as spatial information divided into quarters of its area as shown in FIG. Will be.

The above is performed for X-rays in all regions. Then, by deconvolving these data, an image having a resolution of / 4 of the area of the detection element s ‥‥ s is obtained.

In the present invention, the number of detection element rows is not limited to three, but can be any n rows and one.
The moving amount of the step is not limited to 1/2 of the diagonal line of the detecting element s, but can be set to any 1 / m, and the number of counter rows is set to m × (n + 1) according to the n and m.
And it is sufficient. Further, the shape of the sensitive surface of the detection element s ‥‥ s is not limited to a square, but may be, for example, a rectangle as shown in FIG. 6 or an arbitrary parallelogram.

<Effects of the Invention> As described above, according to the present invention, in the multi-line sensor type radiation image capturing apparatus, the detection element row is
1 / m of the diagonal length of the rectangular detector element in the diagonal direction
Each of the measurement elements is provided with m × (n + 1) counter rows for each of the n detection element rows, and the detection signals from the detection element rows are sequentially switched at each measurement step and introduced into each counter row. However, by retaining the contents or transferring the data of the counter row remaining for each step, the speed and efficiency of the data transfer can be increased, and the detection element can be easily mounted despite handling a large amount of data. An image with a spatial resolution of 1 / m ² of the area can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, in which (a) is a front view of a detector array 1, (b) is a block diagram showing an entire configuration, and FIG. 2 is a block diagram showing the gate groups 2A and 2B. FIG. 3 is a diagram showing a specific configuration of a gate row G _Ai , G _Bi and each counter row C _{i, j} , FIG. 3 is a block diagram showing a configuration of a control circuit 5, FIG. 4 and FIG. FIG. 6 is an explanatory view of the shape of the sensing surface of a detecting element according to another embodiment of the present invention. 1 ...... detector array 2A, 2B ...... gate array groups 3 ...... counter array group 4 ...... data processing apparatus 5 ...... control circuit _{S 1, S 2, S 3} ...... detecting element array s ... s ...... Detection Element C _1,1 , C _1,2 ... C _4,2 ... Counter row G _A1 ... G _B4 ... Gate row

Claims (1)

(57) [Claims] An output signal from each detection element is counted while moving a detector array in which a plurality of (n) detection element rows in which radiation detection elements are arranged one-dimensionally are arranged stepwise. In a device for obtaining a radiation image by collecting the radiation image in a data processing device, the sensitive surface of each of the detection elements has a rectangular shape, and the detector array is moved in a diagonal direction of the detection element. The moving amount of the step is set to 1 / m (m is an integer) of the length of the diagonal line of the detection element, and m × (n
+1) counter rows are provided, and the counter rows for inputting the output data of the respective detection element rows are sequentially switched at each step of moving the detector array, and the counter rows in which the input is not performed hold count data. And a multi-line sensor type radiation image capturing apparatus configured to perform any one of data transfer to the data processing apparatus.