JPH0731373B2 - Radiation image information reader - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for optically reading radiation image information recorded on a stimulable phosphor panel, and particularly to appropriately deal with deterioration of each component. Related to the device.

[Background of the Invention]

For example, when a stimulable phosphor is irradiated with radiation such as X-rays and ultraviolet rays, a part of the energy of this radiation is stored and recorded in the phosphor, and then the phosphor is irradiated with excitation light,
The phosphor emits stimulated light depending on the stored energy.

The stimulable phosphor panel is a panel having such characteristics and is capable of recording a radiation image such as X-ray of a human body as a latent image. Then, when the latent image portion is irradiated with excitation light such as laser light, stimulated luminescence with an intensity corresponding to the density of the latent image occurs. Therefore, if the stimulated emission light is detected by a photomultiplier (photomultiplier tube) and appropriately processed, a recorded radiation image can be obtained.

FIG. 6 is a diagram showing an outline of a radiation image information reading device 2 using such a stimulable phosphor panel 1. Prior to reading the stimulable phosphor panel 1, an image of a subject 5 such as a human body is recorded by the radiation generator 4 controlled by the radiation controller 3.

This image is formed as a latent image on the stimulable phosphor layer by accumulating energy according to the radiation transmittance distribution of the subject 5 with respect to the radiation dose from the radiation source 4.

In the reading device 2, the light beam generator 6 made of a semiconductor laser generates a light beam whose emission intensity is controlled, and the light beam reaches the scanner 7 via an optical system (not shown), Then, the light is deflected, the optical path is changed by the reflecting mirror 8, and the light is guided to the panel 1 as excitation scanning light.

In the vicinity of the panel 1, a condenser 9 made of an optical fiber is arranged along the scanning line of the excitation light, and stimulated emission light substantially proportional to the latent image energy from the panel 1 scanned by the light beam is emitted. Receive light. Reference numeral 10 is a filter that passes only the light in the stimulated emission wavelength range from the light introduced from the light collector 9, and the light passing therethrough is incident on the photomultiplier 11 and converted into a current signal corresponding to the incident light. To be converted. 12 is a high voltage power supply for the Photomul 11.

The output current from the photomultiplier 11 is converted into a voltage signal by the current / voltage converter 13, amplified by the amplifier 14, and then converted into digital data of a predetermined number of bits by the A / D converter 15.
Then, this digital data is input to the arithmetic unit 16 and subjected to image processing (for example, gradation processing, frequency processing, movement, rotation, statistical processing, etc.), and the processed data is output for printing or display. It 17 is panel 1 after reading
It is an erasing lamp consisting of a halogen lamp with a cover for erasing the afterimage of.

By the way, the stimulable phosphor panel 1 used in this device
Other parts may be regenerated, replaced, or
Correction etc. will be necessary. The timings of reproduction, replacement, correction, etc. are mainly a function of the total number of read images and the accumulated elapsed time. If the proper time is missed, there is a possibility that reproduction cannot be performed or the device cannot be used. is there.

[Object of the Invention]

It is an object of the present invention to provide a radiation image information reading device in which such reproduction, exchange and correction are accurately performed.

[Structure of Invention]

To this end, the present invention is a radiation image information reading device configured to scan a stimulable phosphor panel storing and recording radiation image information with excitation light and photoelectrically read the radiation image information stored and recorded. In, a cumulative counter for measuring the usage time of the device, the number of times the panel is read, or the number of times the panel is erased, and a correction data generator for generating correction data for adjusting the system sensitivity of the device by the output of the cumulative counter. And means for resetting the integrating counter by replacing the panel.

〔Example〕

Examples of the present invention will be described below. First, as shown in FIG. 2, the sensitivity of the stimulable phosphor panel 1 decreases with the elapsed time (cumulative use time). This can be regenerated within a reproducible range mainly due to moisture absorption, and the impression is restored. Therefore, if the limit sensitivity of reproduction is A and the elapsed time at this time is T ₀ , this time
When the time is within T ₀ , for example, each time T ₁ elapses and the sensitivity is recovered as shown in FIG. 3, long-term use becomes possible.

Then, since the sensitivity deterioration up to the reproduction in this case is a time function, the sensitivity can be corrected. As shown in FIG. 4 (b), this correction method is such that if the system sensitivity of the entire device is adjusted to a characteristic that cancels the sensitivity change of the stimulable phosphor (FIG. 4 (a)), the corrected total As shown in FIG. 4 (c), the sensitivity of has a characteristic that it is not affected by the passage of time.

FIG. 1 is a diagram showing an outline of an apparatus of this embodiment which is adapted to perform such a correction. In this embodiment, as an integrator for measuring reading, an integrator 18 for measuring the usage time of the device is used.
The measurement data obtained here is sent to the correction data generator 19, and the correction data (function of time) generated by the correction data generator 19 is supplied to the high voltage power supply 12 for the photomultiplier 11 and the light beam generator. 6, it is sent to the arithmetic circuit 16 and the like to adjust the respective parts.

As a result, the output of the semiconductor laser, the sensitivity of the photomultiplier 11, the digital arithmetic processing method, etc. are adjusted, and the overall sensitivity of the system can be adjusted as shown in FIG. 4 (b). The integrator 18 is reset to “0” by, for example, exchanging the phosphor panel (by a micro switch which is turned on when the phosphor panel is inserted and turned off when the phosphor panel is taken out).

By the way, the integrated time meter 18 measures the usage time, but it may be replaced with an integrated measuring instrument for measuring the number of read sheets. As shown in FIG. 5A, the total lighting time of the semiconductor laser is proportional to the number of read sheets. Further, as shown in FIG. 5 (b), the total irradiation time of the erasing lamp 17, which is a halogen lamp, is also proportional to the number of read sheets. And
As shown in FIG. 5 (c), the erasing lamp 17 has a reduced irradiation light amount depending on the number of read sheets, so that the residual image erasing ability also deteriorates, and when the light amount is below a certain amount, the previous image remains,
The S / N of read data will decrease. Also, since the support and protective film of the stimulable phosphor panel are exposed to a strong lamp or laser beam and gradually deteriorate, the panel should be replaced not only by time management but also by the number of erasing and reading. Or it is desirable to issue a warning.

On the other hand, if the integrated counter is provided and the number of read sheets is counted, the total lighting time Ta
A warning prompting the replacement of the semiconductor laser can be generated when the number of scanned sheets S ₁ corresponding to (the time indicating the usage limit) is
Similarly, the erasing lamp 17 can also issue a similar warning when the number of read sheets S ₂ corresponding to the total lighting time Tb, which is the end of life, and the erasing lamp 17 has a light intensity of S / N.
A similar warning can be issued even when the number of read sheets S ₃ that affects B. Further, it is possible to issue a warning so that the deviation of the mechanical portion due to vibration or the like can be adjusted according to the number of read sheets.

〔The invention's effect〕

From the above, according to the present invention, the deterioration of the panel sensitivity is detected by the integrating counter, and the system sensitivity of the entire apparatus is corrected in accordance with the detection, so that the overall system sensitivity is kept the same regardless of the deterioration of the panel. it can. Further, since the integrating counter is reset when the panel is replaced, the system sensitivity is also reset.

[Brief description of drawings]

FIG. 1 is a block diagram of a radiation image information reading apparatus according to an embodiment of the present invention, FIG. 2 is a characteristic diagram of sensitivity deterioration of a stimulable phosphor, and FIG. 3 is an explanatory diagram of restoration of sensitivity of the phosphor. FIG. 4 is an explanatory diagram of system sensitivity adjustment according to sensitivity deterioration and restoration of the same phosphor, FIG. 5 is an explanatory diagram of aging characteristics of a semiconductor laser and an erase lamp, and FIG. 6 is a conventional general radiation image information. It is a figure which shows the block of the apparatus of the recording / reading of.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideyuki Handa No. 1 Sakuramachi, Hino-shi, Tokyo Photo of Konishi Roku Photo Industry Co., Ltd. (72) Masafumi Saito No. 1 Sakuracho, Hino-shi, Tokyo Photograph of Roku Konishi Photo Within

Claims (1)

[Claims] 1. A radiation image information reading apparatus configured to scan a stimulable phosphor panel storing and recording radiation image information with excitation light to photoelectrically read the radiation image information stored and recorded, An integration counter for measuring the usage time of the device, the number of times the panel has been read or the number of times the panel has been erased, and a correction data generator for generating correction data for adjusting the system sensitivity of the entire device by the output of the integration counter. And a means for resetting the integrating counter by replacing the panel, the radiation image information reading apparatus.