CN1024224C - X-ray perspective projection liquid crystal light valve imagning system - Google Patents

Abstract

The present invention relates to an X-ray perspective liquid crystal light valve projection imaging system which comprises an X-ray luminescent screen, a weak light objective lens, a weak light image intensifier tube, a liquid crystal light valve, a polarizing beamsplitter, a light distributor, a projection light source, a projection objective lens, a projection screen, etc. The present invention is characterized by bipolar enhancement and liquid crystal imaging; the bright light of an outer light source is utilized for displaying bright color X-ray images with high resolution through optical projection; the colors of the images are adjustable, positive images and negative images are changeable, and the projection area can be changed at will; thereby, the images in practical size, in part amplification, or in full frame size can be observed at any time.

Description

X-ray perspective projection liquid crystal light valve imagning system

The present invention relates to medical image and liquid crystal image technical field, especially relevant with the X line perspective imaging technology of ionising radiation imaging.

So far, medical X line fluoroscopy system mainly is that X line video screen, image strengthen speculum and x-ray tv, and closely connects four kinds of type image amplifiers.Their common trait is that display itself is luminous, fluorescence imaging and fluorescent screen show.Because rely on and self provide luminous energy, brightness is limited, is subject to ambient light effects.Traditional simple and cheap device, brightness is low, provides information few, and the inconvenience of working in the darkroom.And modern fluoroscopy system again because of complex structure, costs an arm and a leg, and volume and weight are huge and limited their universal scope.

In addition, the previous trial that application liquid crystal display X line image was once arranged, such as GB1.435.373, FR7214614, the clear 50-34194 of TOHKEMY, GB1.509.823, U.S.P3.939.345, GB2005857A, FR7728738, and the relevant scheme in the several schemes that propose in paper " liquid crystal XRII " (abstract of a thesis is stated from supplementary issue VII in 1979 59-60 of Inst. of Physics, CAS's " physical communication " page or leaf) literary composition in national liquid crystal academic conference in 1979, reported of the inventor.

Previous these trials, though scheme is different, its common ground is to take to shield the technology path of changing X line image by large-area liquid crystal.Yet, because in the flat device very big at area, that constitute by multi-layer solid film and one deck liquid film, the homogeneity that is difficult to make the necessary liquid crystal film as thin as a wafer of quick response and guarantees each rete.So mostly " preferentially select " the thicker storage-type liquid crystal of rete for use, utilize its memory effect, show static image intermittently.Must observe the diagnosis requirement of Real-time and Dynamic image continuously because they can not satisfy medical perspective, thereby still not have the X line fluoroscopy system appearance of medical liquid crystal imaging so far.

Liquid crystal display can be brought into play its advantage well in miniature device.Show at the paper that is entitled as " liquid crystal light valve is used for real-time light data processing " (be published in " optical engineering " 17 volumes 1978 4 phase 371 pages) as W.P. mine-laying Kazakhstan etc., reflective photoconduction-the liquid crystal light valve of optical-write-in mode, have resolution greater than 40 lines right/millimeter, contrast greater than 100: 1 and periodic response time less than characteristics such as 50 milliseconds; B.S. flood etc. is pointed out at the digest that is entitled as " liquid crystal light valve is used for the giant-screen diagram and shows " (be stated from U.S. information in 1979 and show the 22nd page of the inner collection of thesis of association), that the resolution of light valve reaches 50 lines is right/millimeter, 1 inch light valve has 1, the exploring degree that 000 * 1,000 resolution element is above.The contrast of large screen projection was greater than 30: 1, and response speed is greater than 30 frame/seconds; The above-mentioned same sampling device of U.S.'s " information demonstration " 1979 10 phase 14-15 pages or leaves report, the colour contrast of projected image be greater than 70: 1, projector distance from 15 centimetres until 9 meters, be 50 times at its magnification of 4.2 meters typical range; W.E.L. Haas etc. is published in the appended high-quality portrait picture of " applied physics communication " 29 volume 1976 10 phases, papers of 631 pages and shows being entitled as " extra low voltage image intensifier ", the resolution of light valve surpasses 90 lines right/millimeter, and gray level reaches 12 grades.

More above-mentioned major parameters show that small-sized light valve projective large-screen shows that its picture quality and response speed can reach above-mentioned diagnosis requirement.But, (be about 8 * 10 and the brightness of X line fluorescent screen images is very low because the X line can not focus on ^-3-3 * 10 ^-2Nit), far below the luminous sensitivity threshold (for example 10.76 luxs) of the photoconduction-liquid crystal light valve that transmits by fiber optics, deficiency is so that liquid crystal work.Though thereby the liquid crystal light valve projective large-screen shows and to have reached practicability at other field, uses as yet so far at medical domain." image intensifier tube/liquid crystal light valve device " that " the light emitting diode image tube light valve " of on January 23rd, 1975 application and the U.S3.971.931 that announces on July 27th, 1976 and W.P. mine-laying Kazakhstan in 1978 etc. are described in above-mentioned paper, though apparatus structure, purposes and characteristics have nothing in common with each other, but concurrent is all to have increased the relaying enhance device, thereby provides possibility for liquid crystal light valve Projection Display twilight image.The present invention is with above-mentioned to shield the technology path of changing X line image by large-area liquid crystal different, the present invention is improved on the basis of a scheme in above-mentioned liquid crystal XRII paper, has taked the liquid crystal light valve projective large-screen of small size to show another technology path of medical perspective X line image.

One object of the present invention is to utilize feature of LCD display, for medical X-ray is had an X-rayed the imaging technique that a kind of novelty is provided, so that a kind of inexpensive light fluoroscopy system that is suitable for popularizing of Development and Production;

Another object of the present invention is solve to use large-area liquid crystal screen X line video conversion in practicality problem medically, and an approach that reality is feasible is provided.

In order to achieve the above object, perspective imaging of the present invention system as shown in Figure 1, it is the reflective liquid crystal light valve that drives as the control of the optical-write-in mode photoconductor of meron, alternating voltage by with fibre optic faceplate, with with the small-sized twilight image reinforced pipe butt joint of fibre optic faceplate, form the mode of the two-stage enhancing of fiber optics coupling as the input and output window.From high resolving power X line luminescent screen and the twilight image that after lens focus, dwindles, strengthen and convert to real big, amplify or the high resolving power of dwindling and bright projected image.It is to have the x-ray imaging system that strengthens and show two kinds of functions all over the body concurrently, is mainly used in perspective, also can be made for the bright image source of small pieces photograph, telephotography and the process photography of spot film photograph.This system comprises: an X line source 1, an elite X line luminescent screen 3, the information translation of bringing when the X line is seen through human body 2 becomes fluoroscopic image, the focusing of a fluoroscopic image that dwindles luminescent screen 3 or catadioptric focus apart from or the low-light object lens 4(or the Shi Laite mirror-lens system of varifocal, one is enhanced to the twilight image reinforced pipe 5 that has fiber optics input and output window than bright image to above-mentioned small size image, an optical-write-in mode reflective liquid crystal light valve 6 that docks with image intensifier tube 5, the liquid crystal imaging mode that the two-stage that makes it form the fiber optics coupling strengthens, projection light source 7 and lens combination 8, the projected light of collimation is provided for above-mentioned light valve 6, one by the polarization beam splitter 9 of two quartz rectangular prism orthogonal configuration and (fixing by 1 to 3, or it is movable, total reflection or half transmitting) level crossing 10, the image conversion apparatus 14 that 11 light distributors of forming 111 are constituted, a focusing, amplify the polarized light projection objective 12(that has information that polarization beam splitter 9 transmits focus apart from or varifocal), accept projection optical screen 13 that projection objective 12 transmits and camera bellows 401 and controller etc. for one.The color of this system's gained image, size, positive and negative adjustable.

Above-mentioned X line luminescent screen is by ZnS.CdS: Ag, BaFCl: Eu, CaWO ₄, LaOBr: Tb, Cd ₂O ₂S: X line luminous materials such as Tb are coated in to be made on separately the substrate, its resolution height, and twilight sunset is short, high definition and dynamic twilight image can be provided.

The luminescent screen substrate can be square papery flat board, also can be round, with the spherical nick thin plate of low atomic number metal forming.

This projection imaging system with focusing apart from the low-light object lens, is used objective with variable focal length in multifunction system in single system.

Above-mentioned twilight image reinforced pipe 5 has fiber optics input window and output window, can be microchannel thin slice pipe, or microchannel inverted image pipe, three grades of electrostatically focused tubes, and its luminance gain should be greater than 10000 times.As adopt 20000-100000 image tube doubly.

Its light valve is to write as meron, light with fibre optic faceplate, photoconductor control, and AC driving, to mix the reflective liquid crystal light valve of field effect mode work, the output window of its above-mentioned meron and above-mentioned image tube 5 is to being connected into the fiber optics coupling.

Above-mentioned polarization beam splitter 9 is to be formed by two right-angle prism orthogonal configuration with light polarisation.

Its light distributor contains 1 to 3 facet mirror, works respectively for 1 to 3 passage imaging (as projection, TV, take a picture or make a flim), or the usefulness of working simultaneously.

The projection objective of native system is that objective with variable focal length or camera lens are telescopic, can throw the image of different area with the distance that is suitable for fixing.

Camera bellows 401 side of being or circle truncated cone shape, inside surface is the strong light metal alloy structure of all black, light weight and rigidity.

In said system, projection light source is used halogen tungsten lamp in single system, uses xenon lamp in multifunction system, and all is furnished with cold light reflection, air-cooled and collimation optics.

A low-voltage dc power supply is housed in the controller of said system, a low-voltage alternating current power supply, the power supply of a projection light source, direct supply the two poles of the earth binding post is by the extension line corresponding connection of lead with the voltage divider of above-mentioned image intensifier tube 5.Two binding posts of AC power are connected by the extension line of lead with above-mentioned former and later two transparent telegrams of liquid crystal light valve.

Said projection screen is made back projection type or pre-projecting type with the organic material flat board, also can be made into dual-purpose type, and screen is fixed in above-mentioned single system, and in multifunction system, screen is two screens can removing automatically and reset.

This system compares with previous similar techniques, and its major advantage is, because the light valve area is very little, can overcomes to shield and change the above-mentioned technical difficulty that X line image is faced with large-area liquid crystal, thus can be for medically practical.

Native system compares with the medical fluoroscopy system in modern times, and its major advantage is to use the passive-type display technique, and brightness of image depends on outer light source rather than relies on display itself luminous; Utilize the combination property of two class compact image boosters, its luminance gain is than the high 5-6 of existing large-scale XRII (X-I.I) order of magnitude.Thereby make optical projection giant-screen X line image become possibility; Different with the obvious visible television image of scan line, the image of optical projection is continuous picture, and the sharpness height, can closely shield to observe tiny lesion shadows; The area of projected image can be put into effect greatly or the change of amplifying at any time, for perspective, the consultation of doctors or teaching application.Preliminary experiment proves the supply voltage of this system's critical piece and operating voltage very low (under the frequency of 100KHz), the operating voltage of light valve is the 1.2-1.25 volt, the voltage divider power supply of image tube (electrostatic focusing formula, 100 times of luminance gains closely connect input X line fluorescent screen images) is 2.6 volts of direct currents; X line image colour on the screen is adjustable; The arbitrarily conversion of the plus or minus of image.In addition, owing to do not contain any sweep unit in the simple optical projection system, and non-essential part is assembled in the controller of establishing in addition, thereby the volume and weight of projection system main body, simpler and light than image intensifier television system.

Positive effect of the present invention also is, except that traditional video screen arrangement for perspective, this fluoroscopy system will be much lower than the price of other existing fluoroscopy system, it is estimated, be the imaging system of 1 to 3 passage equally, the possible price of native system is about image and strengthens 1/3 to 1/5 of x-ray television system price.

Below, will be in conjunction with the accompanying drawings, principle of the present invention and the embodiment that is used for illustration purpose are described.In the accompanying drawings:

Fig. 1 is a medical X-ray fluoroscopy system sketch of the present invention.

Fig. 2 is the schematic diagram of fluoroscopy system of the present invention.

Fig. 3 is the real cut-open view of system shown in Figure 2 major part.

Fig. 4 is the schematic diagram of the microchannel plate 54 of image tube shown in Fig. 35.

Fig. 5 is that analysing and observe of a microchannel amplifies and the electron multiplication synoptic diagram in the expression channel plate 54.

Fig. 6 is the cross-sectional schematic of liquid crystal light valve 6.

Fig. 7 is the equivalent electrical circuit of liquid crystal light valve 6.

Fig. 8, the 9th, liquid crystal light valve 6 alternative two kinds of shapes and structures.

Figure 10,11, the 12nd is according to left front view, right view and the vertical view of the duty of the single channel fluoroscopy system device of principle of the invention design.

Figure 13,14, the 15th, front view, right view and the vertical view of the triple channel imaging system work of design according to the present invention.

Figure 16 is the synoptic diagram of the overall and control system of above-mentioned three-way type device.

Mark 1 is an X line source, the 2nd among Fig. 1, patient, the 306th, the main body of this system, the 13rd, projection screen, the 201st, doctor.

Among Fig. 2, X line source 1 is the X spool of 5 to 500 milliamperes or this various X line machine more than capacity.Penetrate and be subjected to the taper X wire harness 101 of multi-leaf collimator 106 constraints to see through patient 2 from X line source 1, the X wire harness 102 that forms carrying information projects on the X line luminescent screen 3, and fluorophor is stimulated and produces visual image 300.The emission spectrum of above-mentioned screen 3 should mate with the response spectrum of image intensifier tube 5, because image tube series is open to whole spectrum, so X line luminescent screen 3 can select to adopt high-resolution ZnS.CdS: the Ag(granularity is less than 10 microns) video screen (peak wavelength 538nm) or utilize through improving the high resolving power X line intensifying screen of (after time is short), for example BaFCl: Eu(380-450nm), CaWO ₄(420nm), LaOBr: Tb(410-490nm) and Gd ₂O ₂S: the Tb(545nm) screen that waits the X line luminous material to make, for example, be 50 microns ZnS.CdS with granularity: the relative output brightness of Ag screen is 100, as its granularity is 5 microns, then exporting brightness relatively is 36, and granularity is 5 microns LaOBr equally: Tb(is LaOBr for example: 0.02Tb) can be for the relative output milli Du Keda 130 of this rare earth screen of changing dynamic X line image.The image light 301 of X line luminescent screen 3 sees through the light beam 302 that is focused after the low-light object lens 4, becomes inverted real image on the input window that is positioned at the above-mentioned image tube 5 on the focal plane.According to illumination and irradiance formula, that accepts on the window can be drawn by following formula as illuminance:

${\mathrm{E\; f}}_P=\frac{\mathrm{\Pi \; L\; s\; c}}{{\mathrm{4\; T}}^2{\mathrm{(1+m)}}^2}$

Picture illuminance in the formula on Efp-image tube 5 input windows, unit is the brightness of lux Lsc-X line luminescent screen 3, and unit is that nit T-T/ number is effective F/ number of object lens 4, (T/ number=F/ √ Tr, Tr is the transmittance of object lens 4 in the formula) the m-magnification, m=b/a=image height/screen height=image distance/screen distance.

According to X line luminescent screen 3(14 " * 14 ") the useful area length of side be 350 millimeters, ZnS.CdS: Ag screen brightness 8 * 10 ^-3-3 * 10 ^-2Nit is also got its low value 8 * 10 ^-3Nit, the relative aperture F/0.95 of object lens 4,30 millimeters of focal distance f, transmittance Tr75%(can be 90%), magnification m is 0.0857142, calculate, the result be obtain on the input window of image tube 5 equal 4.42957 * 10 luxs as illuminance Efp.If use the image tube of 5000 times of luminance gains, will export the picture luminance brightness of 69.58 nits on its output window, will obtain the picture illuminance of 22.15 luxs with the liquid crystal light valve 6 that 5 one-tenth fiber opticses of image tube are coupled.Though reached and surpassed the photosensitive threshold of light valve 6; light valve can be worked; but also to consider following factors; promptly; for making the light valve 6 can be with response speed work faster; the illumination that needs is far above above-mentioned threshold value illumination (for example 10.76 luxs); the conversion efficiency that causes because of X line luminescent screen 3 and image tube 5 and light valve 6 triangular Spectral matching degree changes; brightness when utilizing X line intensifying screen as above-mentioned screen 3 changes; and for protecting human body; dosage when x-irradiation dosage will be lower than traditional video screen perspective etc. are so that try to achieve a relatively reasonable balance between the factor of these mutual restriction.Therefore, require the luminance gain of image tube 5 should be greater than 10000 times, as adopting 20000-100000 image tube doubly, twilight image reinforced pipe 5 can adopt micropassage type image tube or the electrostatic focusing formula image tube that has fiber optics input and output window.As microchannel thin slice pipe, 40 millimeters of its effective diameters, 60 millimeters of maximum gauges, 20 millimeters of maximum lengths, 25000 times of luminance gains, the degree of distortion are zero, resolution 30 lines are right/millimeter, mean sharpness with 2400 equivalent electric sight lines.Microchannel inverted image pipe and for example, 25 millimeters of effective diameters, 38 millimeters of maximum gauges, 65 millimeters of maximum lengths, luminance gain can transfer to 100000 times, and resolution 35 lines are right/millimeter, sharpness can reach 1750 equivalent electric sight lines.Three grades of electrostatic focusing formula pipes for another example, 25 millimeters of effective diameters, 50 millimeters of maximum gauges (containing voltage divider), long 150 millimeters, 50000 times of luminance gains, resolution 30 lines are right/millimeter, sharpness reaches 1500 equivalent electric sight lines.These several image tubes can be selected for use with concrete conditions such as sources as required.Input picture through image tube 5 and light valve 6 as at accompanying drawing 3 to enhancing and the conversion described in the explanation of accompanying drawing 9.Light 701 scioptics 8 from light source 7, form equality or collimated light beam 702, and reflect into into light valve 6 through polarization beam splitter 9, from light valve 6, reflect the light transmission polarization beam splitter 9 that has information, be reflected at the level crossing 10 of light distributor 111 from the light 705 that wherein transmits, reflected light 706 is again through level crossing 11 reflections, reflected light 707 focuses on by projection objective 12, projected light 708 projects on the screen 13, thereby obtains high-resolution and the bright big or enlarged image 709 of reality.Actual conditions when using, level crossing 10 and 11 they can be one or two, fixing or movable, total reflection or half transmitting.Screen 13 is translucent (back projection types with) or opaque (pre-projecting type with) or can be general for above-mentioned two formulas, but their position be fix or lateral slip.Object lens 4 and 12 focus distance or varifocal.

Image tube 5 among Fig. 3 is to be example with microchannel thin slice pipe, and its performance is good, and volume and weight is little, and its volume is about 1/400 of above-mentioned X-I.I volume.Picture light 302 imaging on the outside surface of the fiber optics input window 51 of image tube 5 that focuses on through low-light object lens 4, and the photocathode 52 of being defeated by the inside surface place that is positioned at window through fiber optics, photocathode 52 causes that because of being subjected to illumination photoemission produces an electronic image.These electronics cross the vacuum electric field and arrive microchannel plate 54 under the effect of the distribution voltage V1 of voltage divider 58, the electronics that enters the microchannel causes continuously according to Fig. 5 principle in the high-voltage electric field of voltage V2 and increases progressively.Multiplication electronics 55 is quickened by the stronger electric field of voltage V3 again, impacts the video screen 56 on opposite, produces a tangible image.The image light that strengthens arrives light valve 6 by the fiber optics coupled transfer of output window 57 and light valve meron.Be converged to collimated light 702 from the light 701 of projection source 7 through lens combination 8 and incide polarization beam splitter 9, at this moment light beam is divided into polarized component, and the P polarization sees through prism and the S polarization is reflexed to light valve 6 by prism inclined-plane 92.When linearly polarized light 703 incident liquid crystal, because of the polarization of incident light direction, according to above-mentioned voltage pattern rotation.The polarization direction of the light 704 that is reflected by the light valve dielectric mirror is also according to above-mentioned fluorescent screen images rotation, so when its polarizing prism 91 by quadrature and 93 time once more, emergent light 705 just becomes the corresponding strength variation for above-mentioned projection imaging.

The two sides of the microchannel plate 54 of the image tube 5 on Fig. 4 is added with the above-mentioned voltage divider 58 of the voltage V2(that is about 1000 volts by the DC power supply of the three ten-day period of hot season only).

Those electronics 53 from photocathode 52 shown in Figure 3 among Fig. 5 arrive microchannel plate 54, incident electron 531 enters the microchannel 543 of inclination a little, electronics clashes into the conduit wall 541 of the emission layer 542 that scribbles secondary emission material continuously in the electric field of voltage V2, cause that constantly secondary causes the chain propagation of electronics, so the outgoing electron 550 in the exit of microchannel 543 doubles with geometric series, accelerating impact video screen 56 through above-mentioned voltage V3 produces the fluoroscopic image that strengthens, for activating liquid crystal light valve 6.

Fig. 6,7,8, the 9th, the schematic diagram of liquid crystal light valve shown in Figure 3.It is that promptly off-state is to utilize 45 ° of twisted-nematic effects with the work of mixing field effect mode, and on-state is then utilized electro-optic birefringent effect.Using this effect, be because it has the good advantage with colored contrast of brightness high definition, and response speed is fast, is suitable for dynamic demonstration.

Fig. 6 is the cross-sectional schematic of liquid crystal light valve 6, at meron 61 is on the inside surface of fibre optic faceplate, plates indium tin oxide transparent electrode 62, cadmium sulfide photoconductive layer 64, cadmium telluride light blocking layer 65, zinc sulphide cryolite multilayered medium mirror 66 and monox oriented layer 67 successively.On the inside surface that preceding substrate 610 is an optical flat, only plate indium tin oxide transparent electrode 620 and monox oriented layer 69, and the silicon oxide film packing ring 68 of giving prominence to the 2-3 microns than oriented layer 69.Front and back substrate 610 and 61 orientation directions according to oriented layer 69 and 67 are mutually the 45 configuration, method sealing-in according to Fig. 8 explanation becomes liquid crystal cell priming by vacuum biphenyl liquid crystal then, the sealing charging aperture, form a nematic crystal layer 60 as thin as a wafer, its liquid crystal molecule is to arrange along face to rotate 45 ° of orientations simultaneously continuously between two walls.Front and back transparency electrode 620 and 62 is connected on the power supply 63 by an extension line.Driving power 63 is a continuously adjustable square wave or a sine voltage generator in the scope of 10 volts and 300 KHz.The light inlet 561 of writing on light valve 6 left sides is that the output of above-mentioned image tube 5 is as light.The incident light 703 on the right is a linear polarization projection light from above-mentioned polarization beam splitter 9, and emergent light 704 is that the dielectric mirror 66 from light valve 6 reflects, and according to the information that is incident on the photoconductive layer 64, has rotated the light of polarization vector direction with liquid crystal layer 60.

R1 and C1 represent the resistance and the electric capacity of liquid crystal layer 60 respectively among Fig. 7, C2 is the electric capacity of dielectric mirror 66, forward resistance, back resistance and the electric capacity of the P-N knot that R4, (R3+R4) and C3 then represent to be formed by N-type semiconductor CdS photoconductive layer 64 and P-type semiconductor CdTe light blocking layer 65.The square frame that dotted line surrounds is the photosensitive heterojunction that expression is formed by above-mentioned P-N knot, and impedance Z descended when it was subjected to illumination, and and its impedance Z that belongs to dielectric mirror 66 and liquid crystal layer 60 of connecting ₀Constant, at this moment the big portion of voltage V is added on the liquid crystal; Its impedance Z is much larger than above-mentioned Z when photosensitive heterojunction is in dark attitude ₀, at this moment the big portion of voltage V drops on this heterojunction.Therefore, when photoconductive layer 64 is not subjected to illumination, because the voltage that is added on the liquid crystal layer 60 is very little, be lower than the threshold voltage that its electric light activates, the orientations of liquid crystal molecule still keeps twisted state.Though thereby by liquid crystal the direction of its polarization vector has been rotated 45 ° through 91 inclined to one side linear polarization incident lights 703 of prism, still be linearly polarized light according to the emergent light 704 that former sense of rotation is returned again from dielectric mirror 66 reflections, can not be by quadrature pick up polarizing prism 93.Because of there not being projected light output, so be details in a play not acted out on stage, but told through dialogues on the screen 13.As from the output image light 561 of image tube 5 fiber optics substrate 61 and transparency electrode 62 by light valve 6, irradiates light conducting shell 64 and when surpassing its luminous sensitivity threshold illumination, along with the impedance Z of above-mentioned photosensitive heterojunction descends, the voltage that is added on the liquid crystal rises.When surpassing threshold voltage, the major axis of liquid crystal molecule tends to vertical walls, the inclination angle size that they are holded up, the difference according to the electric field strong and weak of the voltage pattern distribution that is equivalent to image information.Birefringence takes place because of the polarization direction of polarized incident light and liquid crystal molecule optical axis direction are inconsistent, and linearly polarized light changes into and is elliptically polarized light.From the emergent light 704 that dielectric mirror 66 reflects, be that liquid crystal has rotated the polarized light of the rotation of polarization direction according to image information, along with its anglec of rotation, light can part by the analyzing prism 93 that shakes.Because the angle of the polarized light polarization that birefringence causes and the transmitance of light all depend on wavelength, the lucky half-twist of a certain specific wavelength, then the light transmission of this wavelength color is exactly maximum.Therefore, by above-mentioned light distributor 111 reflection and object lens 12 projections, at this moment the X line image of bright field and display color contrast just appears on screen 13 through the emergent light 705 of polarizing prism 93 analyzings.

The circular light valve effective diameter of Fig. 8 is 25 and 40 millimeters, and maximum gauge is 42 and 56 millimeters; Thickness is about 12 millimeters.The preceding substrate 610 of Fig. 8 is the optical glass of thick 5-6 millimeter, and meron 61 is fibre optic faceplates of thick 6-7 millimeter.The light valve frame of being made up of frame before the light valve 681 and light valve after-frame 682 all is to process with the high insulation of black organic material.Insulating washer 68 is inorganic thin film circles that periphery plates the 2-3 micron more when plating monox oriented layer 69.Clamp a thin insulation and lighttight elastic seal ring 683 between the frame of front and back.By regulating and screw 684 tightenings, just can keep the thickness evenness and the impermeability of liquid crystal cell.

The square light valve of Fig. 9, useful area are 25 * 25 and 40 * 40 millimeters, and the profile area is 30 * 36 and 45 * 50 millimeters, and thick 8 millimeters, it removes the method for sealing difference, are that all the other are identical with circular light valve with outside the bonding agent 685.Two kinds of shape light valves are compared, circular have sealing-in firmly, be convenient to the image tube butt joint and change advantage such as liquid crystal.But its diameter increases, and material and operation are more, and cost is higher.Square just opposite with circle.Therefore, square light valve is suitable for using in simple system, and circular light valve is applicable to multi-functional imaging system.

Embodiment 1

Shown in Figure 10,11,12 a kind of concrete device of simple light valve projection fluoroscopy system, for cooperating medium and small X line machine to make the usefulness of the routine perspective of upright position and other positions.Shown in the figure, be to be example with a single pass projection imaging system and a kind of perspective compartment X line machine fit applications.

X line source 1 is positioned at x-ray device 103 among Figure 10, and X wire harness 101 penetrates from window during work.Be equipped with device 103 front can lifting and two-way traversing electronic horse block 104, this has the electronic shedding cam 105 that can do both forward and reverse directions rotation at any angle around Z-axis, hollow square column 403 of fixed installation on its ground, the place ahead, its inner chamber is used for circuit trace, the upper end of post is mounted to the carriage 402 of picture system body 306, this front portion is supporting that area is 356 * 356 millimeters, resolution greater than 2 lines right/the micro powder type ZnS.CdS of millimeter: Ag or (LaOBr: Tb) video screen device 303 and, and talkback microphone 290 and loudspeaker 292 by the tapered camera bellows 401 in the side of light metal sheet forming.The rear portion of carriage 402 is then being supported its inside and relative aperture is being housed 1: 0.95,350 millimeters of the low-light object lens 4(object distances that focal length is 30 millimeters), homemade 3XZ25/25F type or the beautiful C33097 type twilight image reinforced pipe 5 that produces, the liquid crystal light valve 6 that (referring to back Figure 15) useful area 25 * 25 or diameter are 25 millimeters, form and the polarization beam splitter 9 of orthogonal configuration by the right-angle prism of two quartz, be about 30 * 40 millimeters the level crossing 10 and the figure image intensifying/conversion equipment 14 of parts such as 11 with area, and F/2.8, the projection objective 12 of f75 millimeter and by having cold light bowl 700, the halogen tungsten lamp of cold mirror 710 or xenon lamp (400-600 watt) projection light source 7 and instrument fan 709, and the light supply apparatus 15 formed of parts such as light lens group 8.Projected light beam 708 is expression projecting directions among the figure.

Patient 2 Body Position Change is to control electronic horse block 104 and shedding cam 105 by compartment to carry out among Figure 11, makes to be examined the position and be in from X line source 1, and is subjected to the irradiated site of the X wire harness 101 of multi-leaf collimator 106 constraints.See through that the X wire harness 102 of carrying information projects on the video screen device 303 after the patient 2, produce fluoroscopic image and strengthen and conversion through said apparatus 14.Utilize projection light source device 15 and make projected light 708 project imaging on the screen by projection objective 12.Patient 2 is carried out by microphone 290 and loudspeaker 292 with doctor's conversation.

Projected light 708 projects on the wall 17 at about 1.5 meters of central shaft of above-mentioned conversion equipment 14 among Figure 12, side surface in the screen window 171 is meticulous sanding, or with the organic glass or the glass screen 13 of pure white homogeneous film, the image of doctor on colourless optics lead glass 131 view screens 13.Lead glass 16 by view window 172 and with talkback microphone 29 and loudspeaker 291 is observed and the action of patient directions 2.The control of X line machine, patient posture and imaging system, then by x-ray machine console 18 and imaging system controller 19, compartment is operated and is finished.Because x-ray protection is tight and when using native system required irradiation dose little, thereby be in patient in the bright chamber 27 and the doctor in the Ming chamber 28, will be subjected to less and not influenced by x-ray radiation fully.

Embodiment 2

Figure 13,14, the 15th, a kind of can be with the embodiment of the imaging system of three passage work.Cooperate large-scale X line machine, be made for real big projection perspective, image part amplification, full width large screen projection, the monitoring of spy's inspection radiography, remote or multichannel x-ray tv and X ray examinations application such as PF or shooting X line film.

Shown in Figure 13 is when standing position work, to use first passage one projection and make X line fluoroscopic examination.Can see on the figure, be located in the bright chamber 27 and the patient's 2 that standing X line machine diagnostic bed 108 on, the profile of above-mentioned triple channel imaging system main body 306 and ingredient thereof is housed on spot film device 107.Be X line luminescent screen part 303, camera bellows part 401, figure image intensifying/conversion portion 14 and projection light source part 15, these several parts are that three imaging passages are shared.Penetrating in addition in addition projected light beam 708 projection objective 12 and zoom controller 120 thereof, be used for the telephotography part 22 of second channel, photograph (or process photography) part of using for third channel 260.And microphone 290 and loudspeaker 292; In addition, on the cut-open view of the wall 17 between bright chamber 27 and 28, can see portable screen 13 is housed in act window 173, the electronic act device 176 that moves, and fixing colourless lead glass 131.Screen 13 is to make with organic glass, and its side surface has pure white uniform organic film of one deck or meticulous sanding, and the former can be dual-purpose for pre-projecting type and back projection type, and the latter only is applicable to back projection type.Back projection type is meant that doctor's eyes are in 202 position, observes the diffusion transmission 709a from screen rear projection image 709; Pre-projecting type is eyes are observed above-mentioned projected image 709 at 203 places the 709b that diffuses.But, make light path minimizing primary event, in order to avoid reverted image occurs because the position of the catoptron 10 of above-mentioned light distributor 111 shown in Figure 2 according to the back projection type layout, thereby when only using for pre-projecting type, must be changeed 90 ° to counter-clockwise direction with catoptron 10.Be the pattern of operation before the bed and adopt pre-projecting type that these several parts promptly do not need if in bright chamber 28, be provided with talkback microphone 29 and the loudspeaker 291(X line machine that remote operation platform 180, doctor use).

Figure 14 removes and to see that above-mentioned part profile is arranged, also can see with shown in Figure 13 diagnostic bed 108 bed surface longitudinal centre line on the wall 17 at about 2.2 meters, two curtain windows 173 and 174 are housed, use for projection when making upright position loxosis and clinostatism perspective.Wherein, 80 * 100 centimetres of the areas of screen 13,80 * 120 centimetres of the areas of projection screen 130 when being used for upright position and semierect, projection usefulness during for clinostatism and semireclining position.Radial dotted line among the figure is represented projected light 708 cone-shaped beams, and the dashed rectangle district represents the real macreikonic area of projection; The big square frame of dot-and-dash line district is the imagery coverage of expression large screen projection.Dotted rectangle frame district represents to be equipped with the standby view window of lead glass 16, is under the situation of slidingtype at screen 13 and 130, and this window does not promptly need.

X line source 1 is the bifocus Biangulix among Figure 15.Diaphragm 106 is electric multiblade light choppers, is used for controlling the cone angle of X wire harness 101.Diagnostic bed 108 is can rise automatically, crouch and beddo that bed surface can stretch automatically.Be contained in the X line luminescent screen 3 of the video screen device 303 on the spot film device 107, be with have the 4-7 line right/bromine, lanthana, terbium screen or barium fluochloride: Quan Youping or the calcium tungstate screen or the gadolinium sulfide of high resolving power, short persistence, emission orchid light or the green glow of millimeter: the terbium screen is used for that the X line is seen through patient 2 information afterwards and becomes visible twilight image.Camera bellows 401 has sufficient rigidity, can bear the weight of three imaging passage components.Low-light object lens 4 can be used F/0.95, and 4 times of varifocus objectives of f20-80 millimeter in the time need being amplified the part of image, change focal length by electronic focalizer 41 and get final product.Twilight image reinforced pipe 5 should be used the L-4263 type microchannel thin slice pipe of 40 millimeters of effective diameters, and liquid crystal light valve 6 should adopt above-mentioned circular light valve, and its effective diameter should be consistent with image tube 5, and the two butt joint also makes it become fiber optics coupling with silica gel or optical resin gum.The prism useful area of polarization beam splitter 9 is consistent with light valve 6.The catoptron 10 and 11 of light distributor 111 is semi-permeable mirror preferably, and area is about 44 * 60 millimeters.If use completely reflecting mirror, must have the electronic mirror device 110 that moves, during for the conversion passage mirror 10 or 11 rotations are moved apart light path.Projection light source 7 usefulness are greater than 1 kilowatt xenon lamp, and reflector 700 and reflective mirror 710 should be used the cold light element, and the pupil of light lens group 8 is greater than 40 millimeters, in order to collimated light to be provided.The cooling of light source instrument fan 709, its light, little and noiselessness.Function according to above-mentioned each ingredient, from input fluoroscopic image low-light 301, through the enhancing and the conversion of image tube 5 and light valve 6, provide strong collimated light by the Lights section 15, be loaded with the high brightness polarized light of image information to polarization beam splitter 9 outputs, be three imaging passages, shared high light image source is provided.Projection objective 12 on the first passage is F/1.4,2.24 times of varifocus objectives of f70-157 millimeter, and to adapt to the different needs of real big projection and large screen projection, zoom is carried out by power zoom device 120; Second channel is a telephotography part 22, and fully-reflected plane mirror 20, camera lens 21, optical gate 230 and control parts 231 and pick-up tube 23 are arranged; Third channel is a small pieces photograph part 260, and camera lens 26, shutter 261, film 262 and their automatically controlled transmission 263 are arranged.Two, two passages in three-channel parts, the similar X-I.I triple channel can and require according to actual conditions to match.Hold the shell of above-mentioned each parts and the joint portion of mounted inside, should use light metal structure, make every effort to reduce its volume and weight.For preventing to cause picture noise, should prevent and eliminate any parasitic light.In addition, the light source cooling-part should ventilate fully and prevent that high light from exposing.

Among Figure 15, also see projected light beam 708 is arranged, can be respectively to the screen 13 that slides on one side and 130 and be positioned at the slideway 175 of wall 17, and the electronic act device 176 that moves, screen is equipped with ball in both sides up and down, so slip is light.But the effect of portable screen is an act window double as view window, because normally observe real big image, only use the sub-fraction of two giant-screens 13 and 130,, just can observe action with patient directions 2 across lead glass 131 or 132 so only need remove the part of not projection at that time.Because zone and the size removed are variable at any time, thereby compare with ad hoc view window, it has looking away and the variable advantage of viewing angle, when a screen when carrying out the large tracts of land projection, can remove another screen and come for view window.Like this, the doctor just can utilize the intercom dialogue in bright chamber 28, control X line machine and the imaging system that is arranged in bright chamber 27 by comprehensive remote operation platform 180, is in 202 position observation image at eyes.Control stand 180 can be adorned active pin, where operates so that just move with which screen viewing image.In addition, be located at TV monitor 25 and the video recorder 293 that is connected by vision cable 240 other places, that connect with telephotography part 22 by vision cable 24 on the figure in addition.

When making the projection perspective, use the first passage of light distributor 111.Above-mentioned analyzing is shaken the emergent light 705 of prism 93 through level crossing 10 and 11 folding reflections, then by projection objective (long as square focal distance ratio object space focal length, as to be equivalent to the long shot inversion) 12 projected light 708 is projected on the screen 13.Thereby obtain high-resolution color image than high some ten thousand times of the low-light black white image brightness of importing.Because the above-mentioned object lens 4 and 12 of usefulness are that objective with variable focal length or camera lens are that flexible is regulated here, thereby except that function with above-mentioned simple projection, fluoroscopy system, a local amplification of image and a real big whole large-screen image function that zooms into 80 * 120 centimetres of image have also been increased, for the tiny pathology of observational study and the collective's consultation of doctors or the application of imparting knowledge to students.When the needs large screen projection, make object lens 12 change focal lengths or that camera lens is contracted in doing is mobile by remote control electric zoom controller 120, till large-screen image is clear; When the enlarging projection of needs image part, dwindle the bore of multi-leaf collimator 106 earlier, make the irradiation field of X wire harness 102 only contain that zone that plan is put greatly, remote control adjustment object lens 4 and 12 focal length are amplified to until this zone till the multiple and image definition of requirement then.

If in the projection perspective, also needing provides same image to distant place or multichannel, then uses the second channel of light distributor 111.At mirror 11 is under the situation of semi-permeable mirror, incident light on this minute surface 90% is reflected and is used for projection, 10% transmission power supply is looked shooting and is used, only need open optical gate 230, the transmitted light of mirror 11 makes pick-up tube 23 exposures through mirror 20 reflections and by camera lens 21, and vision signal provides television image by cable 24 by monitor 25, connect with video recorder 293 by vision cable 240, also can record a video simultaneously.

Give over to record if in the projection perspective, want to take a picture, can utilize third channel.At mirror 10 is under the condition of semi-permeable mirror, and according to last reason, its reflected light is for the first and second passage usefulness, and transmitted light is used for taking a picture.Only need by above-mentioned transmission 263 starting shutters 261, see through camera lens 26 from the transmitted light of mirror 10 and make film 262 exposures immediately, and auto-slide one retaining.According to the difference of camera pattern, can connect and take 25 * 35 millimeters or 70 * 70 millimeters or 100 * 100 millimeters egative films.

Do not work simultaneously if require three passages, then above-mentioned mirror 10 and 11 also can be a completely reflecting mirror.When the conversion passage, can utilize the electronic mirror device 110 that moves that relevant catoptron (10 or 11) is moved apart light path or changes its reflection direction.Like this, because passage usefulness of 705 confessions of emergent light of polarization beam splitter 9, its brightness is very high.Thereby projected light 708 is brighter; Take a picture and also shorten the time shutter because of light is very strong; For telephotography,, could use afterwards so must install suitable dim light cover additional because of the luminance limit that this high light can bear considerably beyond pick-up tube.

Figure 16 is the schematic block diagram of the overall and control system of the foregoing description 2.X line source 1 is by x-ray machine console 18 controls (also control desk 18 and imaging system controller 19 can be attached together into above-mentioned comprehensive remote operation platform 180); X line luminescent screen 3 can not adorned lead glass in the application of straighforward operation, but photosensitive part (image tube, light valve, pick-up tube and camera) must have local x-ray protection; The substrate of luminescent screen 3 can be the papery square plate, also can be as shown in phantom in FIG. 3 ' like that, by low atomic number (for example beryllium or aluminium) the round metal sheet forming of the very big spherical nick of radius, the aberration that the latter helps improving the fluorescent quantum utilization factor and reduces object lens 4; Optical system adopts small-sized component as far as possible under the prerequisite that can meet the demands, make every effort to assemble compact to reduce the volume and weight of complete machine; The zoom of low-light object lens 4 is carried out by electronic focalizer 41; The level crossing 10 of light distributor 111 and 11 is if completely reflecting mirror.Their shift in position is carried out by the electronic mirror device 110 that moves; The shutter 261 of camera 260 and the action of film 262 are carried out by automatically controlled transmission 263; The zoom of projection objective 12 or camera lens are flexible to be carried out by power zoom device 120; Television camera 22 controlled device 19 controls, above-mentioned 22 video output is connected with the video input of monitor 25; Being displaced sideways projection screen 13(or 130)) carry out by the electronic act device 176(or unshowned 177 that moves; Electronic parts 109 controlled device 19 controls of multi-leaf collimator 106; The low-voltage alternating current power supply 63(of the low-voltage dc power supply of image tube 5, light valve 6 sees Fig. 8,9), the power supply of projection light source device 15 all is contained in centralized control in the controller 19.In a word, the operation of the electric device of above-mentioned each ingredient, whole controlled device 19(or comprehensive remote operation platform 180) centralized control, carry out respectively by very little micromotor and transmission device.Screen 13(and 130) is the giant-screen of above-mentioned size, can supplies to throw in fact the usefulness of the colored X line image of image, the local amplification of image and the amplification of image full frame greatly.

Claims (10)

1, a kind of medical X-ray perspective projection liquid crystal light valve imagning system, it comprises an X line source (1), the elite luminous optical screen of X line (3), focusing or catadioptric low-light object lens or a Shi Laite mirror-lens system (4) of dwindling the poly-picture of luminescent screen (3) fluoroscopic image, one the twilight image reinforced pipe (5) that has fiber optics input and output window of above-mentioned figure image intensifying, an optical-write-in mode reflective liquid crystal light valve (6) that docks with image intensifier tube (5), make the two poles of the earth that form the fiber optics coupling strengthen the liquid crystal imaging mode, a projection light source (7) and perspective group (8), the projected light of collimation is provided for above-mentioned light valve (6), polarization beam splitter (9) and fixing by 1 to 3 by two quartz rectangular prism orthogonal configuration, or it is movable, the level crossing of total reflection or half transmitting (10), (11) image conversion apparatus (14) that constituted of the light distributor of Zu Chenging (111), one poly-put polarized light that polarization beam splitter (9) transmits focus apart from or the projection objective (12) of varifocal, a projection screen (13), a camera bellows (401) and a controller, this system can get color, greatly, little, just, negative adjustable image.

2, system according to claim 1 is characterized in that above-mentioned X line luminescent screen is by ZnS.CdS: Ag, BaFCl: Eu, CaMO ₄, LaOBr: Tb, Cd ₂O ₂S: X line luminous materials such as Tb are coated on separately the substrate and make, substrate is square papery flat board, or the domed nick thin plate with the low atomic number metal forming of circle, luminescent screen has the resolution height, twilight sunset is short, and high definition and dynamic twilight image can be provided.

3, system according to claim 1 is characterized in that above-mentioned twilight image reinforced pipe (5) is a microchannel thin slice pipe, or microchannel inverted image pipe, or three grades of electrostatically focused tubes, and its luminance gain should be generally 20000-100000 doubly greater than 10000 times.

4, system according to claim 1, it is characterized in that above-mentioned light valve (6) is as meron with fibre optic faceplate, light writes, photoconductor control, AC driving, to mix the reflective liquid crystal light valve of field effect mode work, the output window of its above-mentioned meron and image tube (5) is to being connected into the fiber optics coupling.

5, system according to claim 1 is characterized in that above-mentioned light distributor (111), and 1 to 3 passage imaging is provided, as projection, TV, the usefulness of taking a picture or making a flim and working respectively or working simultaneously.

6, system according to claim 1 is characterized in that above-mentioned projection light source (7) is halogen tungsten lamp in single system, is xenon lamp in multifunction system, and they all are furnished with cold light reflection, air-cooled and collimated light parts.

7, system according to claim 1 is characterized in that the truncated cone shape of camera bellows side of being or circle, and inside surface is a black, is made by light weight, light metal alloy that rigidity is strong.

8, system according to claim 1, it is characterized in that above-mentioned controller is equipped with a low-voltage dc power supply, a low-voltage alternating current power supply, a projection light source power supply, the corresponding connection of extension line of the two poles of the earth of direct supply and the voltage divider of above-mentioned image intensifier tube (5), two binding posts of AC power are connected with the extension line of former and later two transparency electrodes of above-mentioned liquid crystal light valve (6).

9, system according to claim 1 is characterized in that the back projection type that above-mentioned projection screen (13) is made with organic plate material, or pre-projecting type, the screen of dual-purpose type.

10, system according to claim 9, it is characterized in that screen fixes in above-mentioned single system, being used for the real big image of projection, is two screens can removing automatically and reset in multifunction system, is used for the big image of reality of the many positions of projection or the large-screen image that the projection full frame amplifies.

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