US 5,534,709 AGranted

Radiation image reading apparatus

AssigneeFujitsu Limited

InventorsShinichi Yoshimoto, Fumihiro Namiki

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Abstract

In a radiation image reading apparatus, a photostimulated phosphor member absorbs a portion of radiation energy transmitted through an object and stores the absorbed radiation energy as a latent image. An excitation light source irradiates excitation light on the photostimulated phosphor member which then emits photostimulated luminescence light which is received and converged by an image reading device, and the latter outputting, as image information, an electrical signal which is dependent on a light intensity of the photostimulated luminescence light. A source of erasing light, having a spectral distribution band positioned substantially in a visible light region and which is normally ON, includes a shutter which is selectively opened to irradiate the erasing light on the photostimulated phosphor during an erasure time and otherwise is closed. A moving mechanism relatively moves the excitation light source and the image reading device with respect to the photostimulated phosphor member, in a moving direction which is perpendicular to the main scan direction.

Claims22

Dependent claims

A radiation image reading apparatus operable in an alternating sequence of image reading and erasing, comprising:

a photostimulated phosphor member which absorbs a portion of radiation energy, transmitted through an object and incident thereon, and stores the absorbed radiation energy in a form of a latent image;
an excitation light source irradiating an excitation light onto said photostimulated phosphor member in a main scan direction so as to generate the emission of photostimulated luminescence light corresponding to the latent image from said photostimulated phosphor member;
an image reading unit for receiving and converging the photostimulated luminescence light emission from said photostimulated phosphor member and thereby reading image information of the latent image, which is dependent on light intensity of the corresponding photostimulated luminescence light, and outputting a corresponding electrical signal;
an erasing light source producing an irradiating erasing light for erasing residual, stored radiation energy of the latent image remaining in said photostimulated phosphor member at an erasure time, after obtaining the image information of the latent image by said image reading unit, said irradiating erasing light of said erasing light source having a major part of a spectral distribution thereof within a band substantially of a visible light region and said erasing light source further comprising a lamp, a controller and a shutter, the controller maintaining the lamp in an ON condition during the alternating sequence of image reading and erasing but switching the lamp to a reduced power level at times other than when erasing residual radiation energy and controlling the shutter to be closed to prevent irradiating, and to be opened to permit irradiating, the erasing light onto the photostimulated phosphor member for erasing same;
and
a moving unit which moves said excitation light source and said image reading unit with respect to said photostimulated phosphor member in a moving direction which is perpendicular to the main scan direction.

3 more elements

A radiation image reading apparatus operable in an alternating sequence of image reading and erasing, comprising:

a photostimulated phosphor member which absorbs a portion of radiation energy, transmitted through an object and incident thereon, and stores the absorbed radiation energy in a form of a latent image;
an excitation light source irradiating an excitation light onto said photostimulated phosphor member in a main scan direction so as to generate the emission of photostimulated luminescence light corresponding to the latent image from said photostimulated phosphor member;
an image reading unit for receiving and converging the photostimulated luminescence light emission from said photostimulated phosphor member and thereby reading image information of the latent image, which is dependent on light intensity of the corresponding photostimulated luminescence light, and outputting a corresponding electrical signal;
an erasing light source producing an irradiating erasing light for erasing residual, stored radiation energy of the latent image remaining in said photostimulated phosphor member at an erasure time, after obtaining the image information of the latent image by said image reading unit, said irradiating erasing light of said erasing light source having a major part of a spectral distribution thereof within a band substantially of a visible light region and said erasing light source further comprising:
a light blocking member having an end provided with a plurality of light emission openings,
a lamp provided inside the light blocking member and emitting the irradiating emission light through the plurality of light emission openings,
a plurality of shutters respectively positioned at the plurality of light emission openings and selectively and commonly movable to closed positions, for blocking the respective light emission openings and thereby blocking the irradiating erasing light from passing through the respective light emission openings at times other than when irradiating the phosphor member for erasing, and to opened positions, for passing the irradiating erasing light through the respective light emission openings, and
a plurality of common filters respectively corresponding to the plurality of emission openings and positioned thereat, at least in the opened positions of the corresponding plurality of shutters, for passing the irradiating erasing light therethrough, the plurality of filters commonly cutting a selected one of infrared rays and ultraviolet rays from the light emitted by the lamp and passing through the plurality of light emission openings and the corresponding filters when the respective plurality of shutters is opened.

5 more elements

A radiation image reading apparatus operable in an alternating sequence of image reading and erasing, comprising:

a photostimulated phosphor member which absorbs a portion of radiation energy, transmitted through an object and incident thereon and stores the absorbed radiation energy in a form of a latent image;
an excitation light source irradiating an excitation light onto said photostimulated phosphor member in a main scan direction so as to generate the emission of photostimulated luminescence light corresponding to the latent image from said photostimulated phosphor member;
an image reading unit for receiving and converging the photostimulated luminescence light emission from said photostimulated phosphor member and thereby reading image information of the latent image, which is dependent on light intensity of the corresponding photostimulated luminescence light, and outputting a corresponding electrical signal;
an erasing light source producing an irradiating erasing light for erasing residual, stored radiation energy of the latent image remaining in said photostimulated phosphor member at an erasure time, after obtaining the image information of the latent image by said image reading unit, said irradiating erasing light of said erasing light source having a major part of a spectral distribution thereof within a band substantially of a visible light region and said erasing light source further comprising:
a light blocking member having an end provided with a light emission opening,
a lamp disposed inside the light blocking member and positioned relatively to the light emission opening for transmission of the irradiating erasing light therethrough, a shutter being positioned at the light emission opening, such that when the shutter is closed, the transmission through the opening is blocked,
a filter provided at the light emission opening and cutting at least one of infrared rays and ultraviolet rays from the irradiating erasing light for transmission through the light emission opening when the shutter is open, and
a controller which controls said lamp so that said lamp is turned ON with a reduced power at times other than during the erasure time, relatively to the power of said lamp as turned ON at the erasure time;
and
a moving unit which moves said excitation light source and said image reading unit with respect to said photostimulated phosphor member in a moving direction which is perpendicular to the main scan direction.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/299,109Filed 2 Sep 1994
Priority: JP 5-2513457 Oct 1993
Granted: 9 Jul 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H04N 1/0283
Using a single or a few point light sources, e.g. a laser diode: in combination with a light deflecting element, e.g. a rotating mirror
G01N 23/043
And forming images of the material: using fluoroscopic examination, with visual observation or video transmission of fluoroscopic images
G01T 1/2014
Using stimulable phosphors, e.g. stimulable phosphor sheets: reading out of stimulable sheets, e.g. latent image
G01T 1/2016
Using stimulable phosphors, e.g. stimulable phosphor sheets: erasing of stimulable sheets, e.g. with light, heat or the like