Abstract: To minimize the adverse effects of flare in a photostimulable phosphor read out apparatus, the input face of a light guide for guiding light emitted upon stimulation has an elliptical cross section. It is positioned so that one of the foci of the ellipse defining the elliptical cross section coincides with the scan line. The second focus is positioned above the scan line and in the vicinity of the second focus a light beam reflection preventing means is provided so that stimulation light reflected by the input face of the light guide is extinguished. In an alternative embodiment the light guide has a circular cross section and is positioned so that the axis of a cylinder comprising the input face does not coincide with the scan line.

Abstract: A method for quantitative verification of line-wise scanning geometry in a digital radiographic read out system. An x-ray transparent phantom substrate with an embedded ruler having a number of equidistant parallel strips that are opaque on top of a photostimulable phosphor screen so that the ruler is parallel with the direction of line-wise scanning. After x-ray exposure and scanning, the position in the scanning direction of the center of each ruler strip is computed. At least one of the following parameters is determined: average pixel sampling distance, geometric distortion value, and total scanned width.

Abstract: In a radiation image read-out apparatus, a stimulable phosphor sheet, on which a radiation image of an object has been stored, is scanned with a laser beam of a predetermined output power, which causes the stimulable phosphor sheet to emit light in proportion to the amount of energy stored thereon during its exposure to radiation, and the emitted light is photoelectrically detected with a predetermined sampling time. A response speed r ?sec! of the stimulable phosphor constituting the stimulable phosphor sheet, the laser beam output power p ?W!, a picture element size s ?m!, and the sampling time t ?sec! are set such that they may satisfy Formulas (1), (2), and (3):r/(s.multidot.t)<5,000 (1)t/s.sup.2 <80 (2)p.multidot.t/s.sup.2 >1 (3)The radiation image having been stored on the stimulable phosphor sheet is thereby read out quickly and such that a reproduced image having good image quality may be obtained.

Abstract: A method of acquiring an ionizing radiation image including, irradiating a material with patterned ionizing radiation, exciting the irradiated material with excitation radiation to emit light in accordance with the pattern and acquiring the emitted light. The excitation radiation has a wave length which does not cause substantial electron-hole recombinations in said material. Preferably, the irradiation forms luminescent centers in the material and the excitation radiation has a wave length suited for excitation of the luminescent centers.

Abstract: An apparatus for reading a radiographic image on a stimulable phosphor sheet, includes a scanner having a rotatable polygon mirror having N pieces of mirror surfaces so that the scanner scans N lines during one rotation of the polygon mirror, and a correcting circuit for correcting image signals so as to eliminate irregularity caused by the polygon mirror. The correcting circuit includes a memory for storing a correction value for each of the mirror surfaces, a surface detecting circuit to identify a mirror surface used for scanning a current line of the image signals, and a shifting circuit to shift data in the memory to the correction value of the identified mirror surface.

Abstract: By means of a read/write terminal patient identification data stored in a touch memory, an EEPROM, a bar code label or an RF tag are read or identification data are retrieved from a hospital identifictaion system (HIS). On the read/write terminal an examination type is selected from a displayed list of examination types. The patient identification data and the identifier of the selected examination type are associated, stored and transferred onto an RF tag provided on a cassette conveying a photostimulable phosphor screen or onto an RF tag that is attachable to the cassette. After exposure of the screen to X-rays, the RF tag and the photostimulable phosphor screen are read out and the radiation image read out of the screen is processed in accordance with processing parameters associated with the selected examination type.

Abstract: In a radiation image read-out apparatus, a radiation image read-out section reads out a radiation image stored on a stimulable phosphor sheet, and an erasing section erases residual image information remaining on the stimulable phosphor sheet after read-out. A plurality of cassettes each containing therein a stimulable phosphor sheet are loaded in a cassette holding section. The stimulable phosphor sheet is taken out from arbitrary one of the cassettes, transferred to the radiation image read-out section and the erasing section and returned to the same cassette from that the stimulable phosphor sheet is taken out.

Abstract: Prospective abnormal patterns in a radiation image of an object are detected in accordance with an image signal representing the radiation image. A probability density function of the image signal, which corresponds to a region, that is inward from a contour of each of the prospective abnormal patterns having been detected, and a neighboring region, is formed. Probability density function information in accordance with the probability density function is obtained. A definite prospective abnormal pattern, which is among the prospective abnormal patterns having been detected and has a high level of probability that it will be the true abnormal pattern, is detected in accordance with the probability density function information.

Abstract: A radiographic image read out system having on-line performance verification. A number of parameters to be used in a test program are stored together with (a) limiting value(s) for (a) characteristic value(s) resulting from application of the test program. An image signal of a phantom is processed according to the test program to determine at least one characteristic value. At least one limiting value for each determined characteristic value is retrieved from storage and a hard copy of the image of the phantom along with the at least one characteristic value in relation to the limiting value(s) is produced.

Abstract: Scanning apparatus with a scanning and erasing station for scanning and erasing a cassette of the type used in photo-stimulable luminiscence ("PSL") radiography, which apparatus has a cassette receiving station comprising a roll-down shutter (15) for supporting thereon a vertical stack (35) of cassettes to be scanned, lateral grippers (42, 43) for supporting the bottom cassette (33) of said stack at opposite lateral sides thereby to hold said bottom cassette while a bottom supporting roller shutter (15) is temporarily removed, and vertical transfer support cams (51, 52) for taking over the support of the bottom cassette from the lateral grippers, and for first lowering said cassette over a distance equal to the height of the cassette so that the next cassette can be gripped and held by the lateral grippers, and for then further lowering said bottom cassette on the scanning carriage (31) of said scanning station.

Abstract: A chemiluminescent detecting method includes the steps of uniformly irradiating with radiation a stimulable phosphor sheet formed with a stimulable phosphor layer containing a stimulable phosphor which can store an energy of radiation and be stimulated by visible light to emit the energy of radiation in a form of light, thereby storing energy of radiation uniformly therein, selectively labeling a biopolymer with a labeling substance which can produce chemiluminescent light by contact of itself and a chemiluminescent substance, causing the biopolymer labeled with the labeling substance and the chemiluminescent substance to come into contact with each other, and exposing the stimulable phosphor sheet to chemiluminescent light produced by the contact of the biopolymer labeled with the labeling substance and the chemiluminescent substance.

Abstract: A dose distribution analyzer (20) and methods for providing a radiation dose map indicating energy of a spacially variable radiation pattern beamed onto a dose map radiation dosimeter (10). The radiation dosimeter (10) is exposed to a proposed spacially variable radiation pattern such as used in a phantom patient for patient radiation dose treatment verification. The dosimeter (10) is subsequently analyzed by the dose distribution analyzer (20). Such analyzer includes a phosphor stimulator (53), an image forming subsystem (38), and an image sensor (37). A dosimeter holder (32) holds the dosimeter near the phosphor stimulator (53). A system controller (22) is connected to receive image data from the image sensor (37) while the dosimeter (10) is stimulated. The controller (22) utilizes the image data to derive a radiation dose map which indicates the distribution of radiation in the spacially variable radiation pattern which strikes the dosimeter (10).

Abstract: A stimulable phosphor sheet, on which a radiation image has been stored, is exposed to stimulating rays, which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to radiation. The light, which is emitted from the front surface of the stimulable phosphor sheet, and the light, which is emitted from the back surface of the stimulable phosphor sheet, are respectively detected. An image readout from the front surface of the stimulable phosphor sheet and an image readout from the back surface of the stimulable phosphor sheet are thus carried out independently of each other, two image signals being thereby obtained. An abnormal state in the image readout from each of the front and back surfaces of the stimulable phosphor sheet is detected.

Abstract: A universal radiation image identification system for use in an environment such as a hospital wherein an information management system is already available. The identification system is interfaced to the existing information system in order to avoid reentering the identification data with respect to radiological data. The radiological data or image typically is stored in a photostimulable phosphor screen.

Abstract: A system and method for reading and processing a radiation image that has been stored in a photostimulable phosphor screen. An identification station, a read out and processing station and an off-line workstation are provided. A customized and configurated parameter set is generated that links with an examination type a set of parameters. This parameter set is used when controlling operation of each individual station of the system.

Abstract: A radiation image reading and erasing apparatus for deriving image signals in such a manner that an accelerated phosphorescence fluorescent material object, onto which radiation images are accumulated and stored, is scanned with an excitation light, and an accelerated phosphorescence fluorescent light, which is emitted from the accelerated phosphorescence fluorescent material object, is received. The apparatus is designed to obtain image data free of unwanted noises, and to occupy less space. The accelerated phosphorescence fluorescent material object is irradiated with a laser beam passing through a slit member to photomultipliers through reflection between sheets. The slit member may move with up-and-down motions. The sheets are taken-up or sent out by or from the associated take-up rollers, respectively, in accordance with the movement of slit member. The apparatus also has an erasing unit with a movable reflector to erase image information from the accelerated phosphorescence fluorescent material object.

Abstract: A system is provided for reading an image stored on a storage layer radiation screen. The system includes a carousel for holding a storage layer radiation screen and a screen scanning system. The screen scanning system includes a carousel mount on which the carousel may be mounted and a rotation mechanism for rotating the carousel mount, rotation of the carousel mount serving to rotate the carousel about a rotational axis which, in turn, causes the screens held on the carousel to move in a circular path about the rotational axis. The carousel is preferably removable from the carousel mount. The screen scanning system also includes an image acquisition optical system positioned adjacent the circular path of the screen, the image acquisition optical system including an excitation system for focusing an excitation beam on a portion of the screen to cause a light emission, and an emission collecting system for collecting the light emitted from the screen.

Abstract: Stimulable phosphor sheets are superposed one upon another. Each stimulable phosphor sheet is provided with a first layer of a substance, which absorbs neutrons and emits secondary particles, and a second layer of a stimulable phosphor, which can store energy from the secondary particles. The stimulable phosphor sheets are exposed to a neutron beam carrying image information, and neutron images are thereby stored on the stimulable phosphor sheets. Image signals representing the neutron images stored on the stimulable phosphor sheets are then obtained. The image signal components of the image signals are then added to each other, which represent corresponding picture elements in the neutron images. An image signal representing the neutron images stored on the stimulable phosphor sheets is thereby obtained. Alternatively, at least one stimulable phosphor sheet for absorbing neutrons, emitting particles, and storing energy of these particles and, a second phosphor sheet for detecting and storing energy from .

Abstract: Radiation images of a single object are formed respectively with radiation having different energy distributions, and image signals respectively representing the radiation images are obtained. An unsharp mask signal Lu corresponding to super-low frequency is calculated from one of the image signals or from an image signal, which represents the mean-level image of the radiation images and is calculated from the image signals. The values of parameters for a subtraction process are changed in accordance with the unsharp mask signal Lu. The image signal components of the image signals are subtracted from one another, which image signal components represent corresponding picture elements in the radiation images, with the value of each of the parameters being thus changed for different picture elements in each of the radiation images.

Abstract: A calibration technique for a storage phosphor reader which calibrates the storage phosphor reader to the exposure value of the x-ray source measured at the time that the storage phosphor to be read is exposed.

Abstract: Method and apparatus for displaying images obtained by reading out stimulable phosphor screens wherein radiation images are stored. A mosaic type image is composed by means of a plurality of read-out images and said mosaic type image is displayed on a preview monitor or on one of a plurality of preview monitors.

Abstract: In a radiation image read-out method, a radiation image storage panel, on which a radiation image has been stored, is exposed to stimulating rays, which cause the panel to emit light in proportion to the amount of energy stored thereon during its exposure to radiation. The emitted light is photoelectrically detected with a photoelectric read-out device, which has detection characteristics such that it may detect light having wavelengths within a wavelength distribution range different from the wavelength distribution range of the stimulating rays and may not detect light having wavelengths within the wavelength distribution range of the stimulating rays. An image signal representing the radiation image is thereby obtained. An identification code is formed on a portion of the radiation image storage panel by using a fluorescent substance.

Abstract: A radiation image storage panel preferably employable for a double-side reading system has a colored stimulate phosphor layer in which a ratio of weight of phosphor particles to binder is so adjusted as to vary in the direction of depth of the phosphor layer under the condition that a ratio of weight of phosphor particles to binder in a portion up to 1/5 of the depth of the layer from one surface of the layer is lower than the ratio of weight of phosphor particles to binder in the phospher layer, and the portion is colored more deeply than other portion of the phosphor layer.

Abstract: An image plate coated with a photostimulable element and a method of testing a digital device for scanning such plate with respect to various system parameters.

Abstract: A stimulable phosphor sheet, on which a radiation image has been stored, is exposed to stimulating rays, which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to radiation. The light emitted by the front surface of the stimulable phosphor sheet and the light emitted by the back surface of the stimulable phosphor sheet, are detected photoelectrically. The image signal components of the two image signals are subtracted from each other, which represent corresponding picture elements on the front and back surfaces of the stimulable phosphor sheet, difference values being thereby obtained. A judgment is made as to whether each of the difference values falls or does not fall within a predetermined range. In cases where a difference value is judged as being outside the predetermined range, it is determined that an abnormal signal component is contained in at least either one of the two image signals.

Abstract: A first image signal representing a Magen radiation image is obtained by exposing a stimulable phosphor sheet, on which the Magen radiation image has been stored in a subdivision pattern composed of at least a single subdivision, to stimulating rays, which cause the stimulable phosphor sheet to emit light in proportion to the amount of energy stored thereon during its exposure to radiation, the emitted light being detected. The kind of the subdivision pattern of the Magen image is discriminated on the basis of the first image signal or information given by an image recording system, which carries out an image recording operation. The kind of an image recording pattern of the Magen image is determined from the kind of the subdivision pattern, which has been discriminated.

Abstract: As photodetectors for detecting light radiated out of a recording sheet, on which a radiation image has been recorded, during its scanning with reading light, at least a single first photodetector, which has a high detection sensitivity and is apt to undergo a saturation phenomenon at its photoelectric surface, and at least a single second photodetector, which has a low detection sensitivity and undergoes little saturation phenomenon at its photoelectric surface, are utilized. A maximum amount of the amounts of the light, which is radiated out of a region inside of each of predetermined units in the radiation image recorded on the recording sheet, is measured. Image signal components corresponding to a unit, in which the measured maximum amount of the radiated light is larger than a predetermined value, are obtained by using only the signal having been generated by the second photodetector.

Abstract: A radiation image read-out apparatus includes cassette support devices for releasably supporting at least two cassettes, each of which can house a single stimulable phosphor sheet therein. A read-out unit moves between at least two read-out positions, each of which corresponds to one of the cassettes supported by the cassette support devices, and at each of which a radiation image is read out from a stimulable phosphor sheet taken out of each cassette. An erasing device is located so as to correspond to each read-out position. A sheet conveyance system takes a stimulable phosphor sheet out of each cassette, conveys the stimulable phosphor sheet into the read-out unit and the erasing device, and then returns the stimulable phosphor sheet into the cassette. The waiting period of the read-out unit and the waiting period of the erasing device are kept short, and the cycle time for the image read-out and erasing operations is thereby kept short as a whole.

Abstract: A combination is provided comprising a supported or self supporting photostimulable phosphor panel, comprising a photostimulable phosphor layer, the phosphor being capable of storing energy upon irradiation with X-rays and of releasing the stored energy as stimulated emission light upon irradiation with stimulating light and collecting means for stimulated emission light, and showing a restricted angular aperture. The combination comprises a volume reflection hologram H1, situated between the phosphor panel and the light collecting means. The volume reflection hologram H1 reflects stimulated emission light entering the volume reflection hologram under any angle outside a restricted angle, determined by the angular aperture of the collecting means and transmits stimulated emission light entering the volume reflection hologram under the predetermined restricted angle.

Abstract: A vertical autoloader capable of handling a variety of different size cassettes without the use of pallets, which includes a separator mechanism and an indexer mechanism. The separator mechanism has a plurality of partitions that define a plurality of slots, and the indexer mechanism has a plurality of partitions that define a plurality of slots corresponding to the slots defined by the partitions of the separator mechanism. An indexer drive mechanism moves the indexer mechanism with respect to a home position of the separator mechanism, wherein the slots defined by the partitions of the indexer mechanism are moved by one position with respect to the slots defined by the partitions of the separator mechanism.

Abstract: An x-ray cassette (1) to accommodate photosensitive material in sheet form, especially a phosphor film (2), having a cover part (1b), a bottom part (1a) and side parts (1c) joined thereto, the cover part, bottom part and side parts being made of plastic and closing off the cassette interior in a light-tight manner. The cassette has at least one electrically conductive element (6) which covers at least 20% of the surface of the cassette (1).

Abstract: An apparatus for recording and reading a radiographic image formed by exposing a subject with radioactive rays includes a cooling device to cool a photostimulable phosphor containing iodine to a range of 250K to 300K. The cooled photostimulable phosphor is irradiated with radioactive rays so that radiographic energies corresponding to said radioactive rays are stored on the cooled photostimulable phosphor. The cooled photostimulable phosphor is stimulated with an exciting light so as to emit lights corresponding to the stored radiographic energies.

Abstract: A storage phosphor radiography patient identification system which matches a patient with an x-ray image of the patient stored in a storage phosphor. The system includes a patient identifying bar code--uniquely identifying a patient; a storage phosphor identifying bar code uniquely identifying a storage phosphor and a portable bar code scanner. The bar code scanner is used to scan the patient bar code and the storage phosphor bar code when a patient is exposed to an X-ray which is stored on the storage phosphor. Preferably, a portable x-ray source has a chart having sets of bar codes identifying x-ray examination type information. The bar code scanner scans the examination type bar codes at the time the x-ray of the patient is taken. The storage phosphor has a non-volatile read/write memory adhered to it. The bar code scanner has a memory probe which transfers the patient ID, storage phosphor ID and exam time information from the bar code scanner to the storage phosphor memory.

Abstract: A radiation image read-out apparatus which comprises an optical system for exposing a stimulable phosphor plate (1) which contains a latent radiation image to a stimulating beam, and a light collector (3) for directing the stimulated light generated in the phosphor plate (1) to a photodetector (4), for example, a photomultiplier tube. Such read-out apparatuses often have the disadvantage that sufficient light cannot be collected into the photodetector. This problem has been solved by using a shiny mirror tube as the light collector.

Abstract: Radiation images of an object constituted of tissues exhibiting different levels of radiation absorptivity are formed with two kinds of radiation having different energy levels. A first original image signal SO1 and a second original image signal SO2 representing the radiation images are detected. A superposition image signal is generated with a weighted addition expressed asS=(N2.sup.2 /(N1.sup.2 +N2.sup.2)).times.SO1+(N1.sup.2 /(N1.sup.2 +N2.sup.2)).times.SO2wherein N1 and N2 respectively represent noise contained in the first and second original image signals. A first image signal representing a first image primarily composed of patterns of first tissues of the object is generated by subtracting the first and second original image signals from each other. A first smoothed image signal representing a first smoothed image, in which noise of the first image has been reduced or eliminated, is generated by smoothing the first image signal.

Abstract: An area detection device for use with X-ray or ultraviolet radiation wherein light from an integrating device is passed through an optical fiber to fall on a phosphor-containing film which is capable of storing a diffraction pattern formed by the transmission of X-rays or ultraviolet radiation through a sample when the diffraction pattern is projected onto the film and also being capable of fluorescing in correspondence to the diffraction pattern. Fluoresced light from the film is directed back along the fiber and into the integrating device and is fed from the integrating device to a photomultiplier which sends a signal from which the diffraction pattern can be detected.

Abstract: A cassette for a radiation image storage panel comprises a box member for housing a radiation image storage panel therein. The box member is provided with an opening, through which the radiation image storage panel is to be fed into and out of the box member. A cover member opens and closes the opening. A small window is formed in either one of the box member and the cover member. An identification mark put on the radiation image storage panel having been housed in the box member is read through the small window from the exterior of the cassette. A lead-containing, plate-like member, which is substantially transparent, closes the small window. The plate-like member is releasably engaged with the small window, and the small window is provided with a protective cover, which covers the plate-like member.

Abstract: Storage phosphor imaging system includes a source of stimulating light, a scanner for scanning a storage phosphor with a latent x-ray image with said stimulating light in a raster pattern to produce an emitted light x-ray image and a photodetector for converting the emitted light x-ray image into an x-ray image signal. The storage phosphor has associated with it a first bar code pattern of alternating bars and spaces for identifying the storage phosphor and a second bar code pattern of contiguous reflective/nonreflective cells for identifying storage phosphor exposure speed and storage phosphor size parameters. A first scanning bar code reader and a second bar code reader including a number of contiguous light emitter and photodetector assemblies, read the first and second bar code patterns, respectively, to produce signals used in identifying, reading and processing the storage phosphor and image signal.

Abstract: A computed radiography patient identification system which matches a patient with an X-ray image of the patient stored in a stimulable storage phosphor. The system includes a patient identifying bar code uniquely identifying a patient; a stimulable storage phosphor identifying bar code uniquely identifying a stimulable storage phosphor and a portable bar code scanner. The bar code scanner is used to scan the patient bar code and the storage phosphor bar code when a patient is exposed to an X-ray which is stored on the stimulable storage phosphor. Preferably, a mobile X-ray source has an associated set of bar codes identifying X-ray examination types (chest, head, limb, etc.) and/or X-ray exposure conditions. The bar code scanner scans the examination type bar code at the time the X-ray of the patient is taken. The system includes a storage phosphor reader for converting an X-ray image stored in a storage phosphor into an X-ray image signal.

Abstract: The invention relates to a radiation image converting apparatus which employs an accelerated phosphorescence fluorescent plate which is rigid or low in flexibility, and it is an object of the invention to provide a radiation image converting apparatus which prevents radiations having passed through an accelerated phosphorescence fluorescent plate from being scattered and irradiated upon the accelerated phosphorescence fluorescent plate again and achieves miniaturization of the equipment and simplification in structure.

Abstract: A method and apparatus for recording the information from the slidable sheet (5) of a RIM cassette (2). The information included on the sheet, used especially in X-ray photography, is read from the sheet surface drawn out of the cassette with the aid of a laser beam focused on it, after which the sheet is emptied of information with the aid of a powerful light and returned to the cassette. According to the invention, the reading is effected during the linear withdrawal of the slidable sheet (5) in the reading position (9) past which the sheet surface including the information is guided, and the removal of the information is effected during the linear return travel of the slidable sheet in the emptying position (10) past which the sheet surface travels while the sheet is being pushed back into the cassette (2).

Abstract: An apparatus for clamping a cassette containing a photosensitive element. The apparatus includes a frame and a stop bar movably mounted to the frame for movement between an operative position and a non operative position. The stop bar has a registration surface for registering the forward end of cassette. A first jaw member is secured to the frame and has a second registration surface for engagement with a first side of the cassette. A second movable jaw member is provided movable between a clamping position and a non clamping position. The second jaw member having a clamping surface for engaging a second side of the cassette opposite the first side of the cassette so as to clamp the cassette between the first and second jaw members when the second jaw member is in the clamping position. A mechanism is provided for moving the second jaw member between the clamping and non clamping positions.

Abstract: A laser imaging apparatus, such as a storage phosphor reader, which converts a latent x-ray image stored in a storage phosphor into an x-ray image signal. Diagnostic routines for the storage phosphor reader are controlled by means of a touch screen monitor which displays a diagnostic screen having a plurality of selectable buttons.

Abstract: First and second stimulable phosphor sheets are located such that the first stimulable phosphor sheet may be closer to a source of radiation. The radiation, which has passed through an object, is irradiated to the first and second stimulable phosphor sheets, and radiation images of the object are stored on the two sheets Read-out image signals A1 and A2 are respectively read out from the first and second stimulable phosphor sheets. Read-out image signals A1us and A2us are obtained respectively from high frequency component eliminating processes carried out on the read-out image signals A1 and A2. The read-out image signals A1us and A2us are subjected to a first operation expressed asB=A1us-.alpha..multidot.A2uswhere .alpha. is a coefficient, and .alpha.>0, and an image signal B is thereby obtained. A second operation is then carried out which is expressed asC=(1-.beta.).multidot.A1+.beta..multidot.A2-.gamma..multidot.Bwhere .beta. and .gamma. are coefficients, 0.ltoreq..beta..ltoreq.1, and .gamma.

Abstract: A method for adjusting conditions comprises the steps of, when a radiation image of a specific object is recorded and read out, investigating whether recording and read-out operations were or were not carried out in the past for the same object as the specific object. When recording and read-out operations were carried out in the past for the same object as the specific object, image recording conditions for the specific object are adjusted such that they coincide with those under which the recording operation was carried out for the same object as the specific object.

Abstract: A surface, on which uniform information has been recorded, is two-dimensionally scanned with light beam deflected by a rotating polygon mirror having reflecting surfaces. Light radiated out of the scanned surface is photoelectrically detected, and groups of reference signal components for correcting purposes are thereby obtained, each group corresponding to one reflecting surface. Each time the groups of reference signal components for correcting purposes, which groups correspond to the whole reflecting surfaces, are obtained while the rotating polygon mirror rotates one turn, an averaging process is carried out on these groups of reference signal components for correcting purposes. A group of correction signal components are generated from a group of reference signal components for correcting purposes, which have been obtained from the averaging process.

Abstract: A radiographical image reader for photoelectrically reading a radiographical image of an object. The image reader comprises a radioactive ray irradiator; a radiographical image converting panel which is a radioactive ray absorbent for absorbing the radioactive ray passed through the object so that a radiographical image information is obtained; a scanner to scan the converting panel with exciting light so that the converting panel is subjected to stimulated emission; a reader to read the stimulated emission of the converting panel so that the radiographical image is obtained; a memory to store at least one of radioactive ray uneven generation information of the irradiator and sensitivity unevenness information of the converting panel; and a processor to compensate the radiographical image information according to at least one of the radioactive ray uneven generation information and the sensitivity unevenness information.