Abstract:
The present invention aims to provide an X-ray detecting apparatus having excellent stability of the support of an X-ray detector, and an X-ray imaging apparatus provided with this X-ray detecting apparatus. The X-ray imaging apparatus has an X-ray irradiating device and an X-ray detecting apparatus opposing to the X-ray irradiating device, wherein the X-ray detecting apparatus has a vertical first column; a second column that is telescopically engaged with the first column; a first raising/lowering mechanism that moves up/down the second column along the first column; a carriage attached to the second column; a second raising/lowering mechanism that moves up/down the carriage along the column; and an X-ray detector held by an arm extending horizontally from the carriage.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Chinese Patent Application No. 200610073612.9 filed Apr. 13, 2006. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to an X-ray detecting apparatus and an X-ray imaging apparatus, and more particularly to an X-ray detecting apparatus in which the height of an X-ray detector is variable, and to an X-ray imaging apparatus provided with this type of X-ray detecting apparatus. 
     There is an X-ray imaging apparatus in which the height of an X-ray detector can be changed in accordance with an X-ray source. In this type of X-ray imaging apparatus, an X-ray detector is supported by an extendable column standing upright from the floor, and X-ray is irradiated from an X-ray source hanging down from a ceiling (see Patent Reference 1, for example). 
     In order to support the X-ray detector with a cantilever method and to change the height thereof, the X-ray detecting apparatus is configured as shown in  FIG. 7 . Specifically, the X-ray detecting apparatus is configured as follows. A carriage  120  is attached to a column  110 , which stands upright from the floor, so as to be capable of moving up and down. An arm  130  is horizontally disposed to the carriage  120 . An X-ray detector  140  is attached to the leading end of the arm  130 . On the other hand, an X-ray irradiating device is configured such that an X-ray source  320  is attached to an extendable column  310  hanging down from a ceiling. 
     [Patent Document 1] Japanese Published Unexamined Patent Application No. HEI10-057360 
     In the X-ray imaging apparatus having the above-mentioned configuration, the column  110  should be long enough to match with the elevating distance of the X-ray detector  140 . In the case where the column  110  is so long as described above, the X-ray irradiating device should be installed such that the column  310  supporting the X-ray source  320  is sufficiently shifted ahead of the column  110  in order to avoid the interference with the column  110 . 
     Therefore, the arm  130  supporting the X-ray detector  140  becomes long, so that the stability of the support of the X-ray detector  140  is deteriorated. Further, since both of the column  110  and the arm  130  are long, the X-ray detecting apparatus is made large-sized, which is inconvenient for packing, transportation, installation, or the like. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to realize an X-ray detecting apparatus having excellent stability of the support of an X-ray detector, and an X-ray imaging apparatus provided with this X-ray detecting apparatus. The present invention further aims to realize an X-ray detecting apparatus convenient for packing, transportation, installation, or the like, and an X-ray imaging apparatus provided with this X-ray detecting apparatus. 
     In order to solve the above-mentioned subject, the invention in the first aspect is an X-ray detecting apparatus comprising: a vertical first column; a second column that is telescopically engaged with the first column; a first raising/lowering mechanism that moves up/down the second column along the first column; a carriage attached to the second column; a second raising/lowering mechanism that moves up/down the carriage along the column; and an X-ray detector held by an arm extending horizontally from the carriage. 
     In order to solve the above-mentioned subject, the invention in the second aspect is an X-ray imaging apparatus having an X-ray irradiating device and an X-ray detecting apparatus opposing to the X-ray irradiating device, wherein the X-ray detecting apparatus comprises: a vertical first column; a second column that is telescopically engaged with the first column; a first raising/lowering mechanism that moves up/down the second column along the first column; a carriage attached to the second column; a second raising/lowering mechanism that moves up/down the carriage along the column; and an X-ray detector held by an arm extending horizontally from the carriage. 
     It is preferable that the first column has a linear guide for the second column in terms of the prevention of meandering of the column in the upward and downward movements. 
     It is preferable that the first raising/lowering mechanism has a combination of a linear actuator and a gas spring in terms of easy extension of the column. 
     It is preferable that the second column has a linear guide for the second column in terms of the prevention of meandering of the column in the upward and downward movements. 
     It is preferable that the second raising/lowering mechanism has a combination of a gear and a chain in terms of easy extension of the column. 
     It is preferable that the first column has an encoder for detecting the absolute height of the X-ray detector in terms of the detection of the height of the X-ray detector. 
     EFFECT OF THE INVENTION 
     According to each aspect of the invention, an X-ray detecting apparatus comprises: a vertical first column; a second column that is telescopically engaged with the first column; a first raising/lowering mechanism that moves up/down the second column along the first column; a carriage attached to the second column; a second raising/lowering mechanism that moves up/down the carriage along the column; and an X-ray detector held by an arm extending horizontally from the carriage, whereby an X-ray detecting apparatus having excellent stability of the support of the X-ray detector and an X-ray imaging apparatus provided with this X-ray detecting apparatus can be realized. Further, an X-ray detecting apparatus convenient for packing, transportation, installation, or the like, and an X-ray imaging apparatus provided with this X-ray detecting apparatus can be realized. 
     Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view for showing a structure of an X-ray imaging apparatus according to one example of a best mode for carrying out the present invention. 
         FIGS. 2   a  and  2   b  are views showing a structure of an X-ray detecting apparatus according to one example of a best mode for carrying out the present invention. 
         FIGS. 3   a  and  3   b  are views showing a structure of an X-ray detecting apparatus according to one example of a best mode for carrying out the present invention. 
         FIG. 4  is a view showing a structure of an X-ray detecting apparatus according to one example of a best mode for carrying out the present invention. 
         FIGS. 5   a  and  5   b  are views showing a structure of a carriage raising/lowering mechanism in an X-ray detecting apparatus according to one example of a best mode for carrying out the present invention. 
         FIGS. 6   a  and  6   b  are views showing a structure of a column extension mechanism in an X-ray detecting apparatus according to one example of a best mode for carrying out the present invention. 
         FIG. 7  is a view showing a structure of a conventional X-ray imaging apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A best mode for carrying out the invention will be explained hereinbelow in detail with reference to the drawings. It should be noted that the invention is not limited to the best mode for carrying out the invention.  FIG. 1  shows a schematic construction of an X-ray imaging apparatus. This device is one example of the best mode for carrying out the invention. The construction of this device represents one example of the best mode for carrying out the invention relating to an X-ray imaging apparatus. Further, a part of the construction of this device represents one example of the best mode for carrying out the invention relating to an X-ray detecting apparatus. 
     As shown in  FIG. 1 , this device has an X-ray irradiating device  200  and an X-ray detecting apparatus  400 . The X-ray irradiating device  200  is one example of an X-ray irradiating device according to the present invention. The X-ray detecting apparatus  400  is one example of an X-ray detecting apparatus according to the present invention. 
     The X-ray irradiating device  200  is configured such that an X-ray source  220  is attached at the leading end of a column  210  that hangs down from a ceiling. The X-ray source  220  changes its direction so as to be capable of changing the irradiating direction of X-ray. The column  210  supporting the X-ray source  220  is extendable in the longitudinal direction, and movable in the horizontal direction along the ceiling. 
     The X-ray detecting apparatus  400  is configured as follows. Specifically, a carriage  420  is disposed to a column  410  that stands upright from the floor so as to be capable of moving up and down. An arm  430  is horizontally attached to the carriage  420 . An X-ray detector  440  is attached to the leading end of the arm  430 . The X-ray detector  440  is a component having a flat-plate shape. It can change its inclination such that the light-receiving surface becomes horizontal or vertical in accordance with the incident direction of the X-ray. 
     The X-ray detector  440  is one example of an X-ray detector according to the present invention. The arm  430  is one example of an arm according to the present invention. The carriage  420  is one example of a carriage according to the present invention. 
     The detection signal of the X-ray detector  440  is inputted to an operator console  600 . The operator console  600  reconstructs the radioscopic image of an object to be examined based upon the inputted signal, and displays the reconstructed radioscopic image on a display  610 . Note that the X-ray detector  440  may be made of a photosensitive material which is photosensitive with X-ray. In this case, the radioscopic image is made visible by a developing process. 
     The operator console  600  controls the X-ray irradiating device  200  and the X-ray detecting apparatus  400  under the operation by an operator. As for the X-ray irradiating device  200 , it controls the horizontal and vertical positions of the X-ray source  220  and the X-ray irradiating direction, and further, the X-ray intensity and irradiating timing. As for the X-ray detecting apparatus  400 , it controls the height of the X-ray detector  440  depending upon the height of the X-ray source  220  and controls the inclination of the light-receiving surface so as to become horizontal or vertical depending upon the X-ray incident direction. 
     The column  410  is extendable in the longitudinal direction. It is continuously extendable from the shortest state shown in  FIG. 2  to the longest state shown in  FIG. 3  under the control of the operator console  600 . In  FIGS. 2 and 3 , (a) is a side view and (b) is a front view. 
     The column  410  is composed of an upper column  412  and a lower column  414  as shown in  FIG. 4 . The upper column  412  is telescopically engaged with the lower column  414 . The lower column  414  is one example of a first column according to the present invention. The upper column  412  is one example of a second column according to the present invention. With this configuration, the column  410  is telescopically extendable. 
     The carriage  420  is disposed to the upper column  412  so as to be movable in the lengthwise direction. The movable distance of the carriage  420  on the upper column  412  is, for example, 830 mm. The movable distance of the upper column on the lower column  414  is, for example, 670 mm. Accordingly, the total movable distance of the carriage is 1500 mm. The length of the column  410  is, for example, 1370 mm minimum and 2040 mm maximum corresponding to the movable distance of the carriage  420 . 
     Even if the X-ray irradiating device  200  is arranged such that its column  210  is coaxial with the column  410  of the X-ray detecting apparatus  400 , both devices do not interfere with each other, since the length of the column  410  is extendable/retractable as described above. The column  410  is extended when the column  210  is shortened for raising the position of the X-ray source  220 . Therefore, both devices do not interfere with each other. 
     Since the column  210  and the column  410  may be coaxially arranged, the length of the arm  430  supporting the X-ray detector  440  can be shortened, with the result that the stability of supporting the X-ray detector  440  can be enhanced. The column  410  and the arm  430  are both shortened, so that the X-ray detecting apparatus is downsized, which is convenient for packing, transportation, installation, or the like. 
     Subsequently, a raising/lowering mechanism of the carriage  420  and extension mechanism of the column  410  will be explained.  FIG. 5  show views of a structure of the carriage raising/lowering mechanism. In  FIG. 5 , (a) is a side view, while (b) is a front view. The carriage raising/lowering mechanism is one example of a second raising/lowering mechanism according to the present invention. 
     As shown in  FIG. 5 , the carriage raising/lowering mechanism has a pair of guide rails  502  and  504 . The guide rails  502  and  504  are attached to both side faces of the upper column  412  so as to be parallel to the shaft. The carriage  420  has inside thereof a slider and roller engaged with these guide rails  502  and  504 . The carriage  420  is movable along the guide rails  502  and  504 . 
     A pair of drive gears  602  and  604  and a pair of driven gears  612  and  614  are provided at both side faces of both edge sections of the upper column  412  for moving the carriage  420 . Chains  702  and  704  are entrained about the drive gear  602  and the driven gear  612  and about the drive gear  604  and the driven gear  614 . A part of the respective chains  702  and  704  is fixed to the carriage  420 . 
     Therefore, when the drive gears  602  and  604  rotate in the normal direction and reverse direction as driven by a motor incorporated in the upper column  412 , the carriage  420  moves up and down along the guide rails  502  and  504  with the rotations. 
     The guide rails  502  and  504  function as a linear guide. The linear guide is one example of a linear guide according to the present invention. The carriage raising/lowering mechanism has the linear guide, whereby meandering of the carriage  420  during the upward and downward movements can be prevented. 
     The portion composed of the drive gears  602  and  604 , driven gears  612  and  614  and chains  702  and  704  is one example of a combination of gear and chain according to the present invention. The carriage raising/lowering mechanism has the combination of gear and chain, whereby raising and lowering the X-ray detector can be easily performed. Note that raising and lowering the carriage  420  is performed not only by the combination of gear and chain but also by a suitable mechanism such as a combination of gear and toothed belt. 
       FIG. 6  show views of a structure of a column extension mechanism. In  FIG. 6 , (a) is a longitudinal sectional view seen from a side, while (b) is a front view. The column extension mechanism is one example of a first raising/lowering mechanism according to the present invention. 
     As shown in  FIG. 6 , the lower column  414  has a pair of guide rails  802  and  804 . The guide rails  802  and  804  are attached to the front and back surfaces of the lower column  414  so as to be parallel to the shaft. The upper column  412  has inside thereof a slider and roller engaged with the guide rails  802  and  804 , and is movable along the guide rails  802  and  804 . 
     A linear actuator  902  is provided in the lower column  414  so as to be parallel to the shaft for moving the upper column  412 . A gas spring  904  is provided parallel to the shaft in the lower column  414 . 
     The working edges of the linear actuator  902  and the gas spring  904  are connected to the upper end section of the upper column  412  at the inside thereof. The linear actuator  902  pushes up or pulls down the upper column  412 . The gas spring  904  generates force against the weight of the upper column  412  for reducing the load of the linear actuator  902 . 
     The upper column  412  is driven by the linear actuator  902 , so that it moves up and down the lower column  414  along the guide rails  802  and  804 . Accordingly, the column  410  is telescopically extended/retracted. 
     The combination of the linear actuator  902  and the gas spring  904  is one example of a combination of linear actuator and gas spring according to the present invention. The guide rails  802  and  804  are one example of a linear guide according to the present invention. 
     The column extension mechanism has the combination of linear actuator and gas spring, so that the column can easily be extended and retracted. Further, it has the linear guide, whereby meandering of the column upon the extension/retraction can be prevented. Note that the upper column  412  is moved up and down by not only the combination of linear actuator and gas spring but also by a suitable mechanism such as a liner motor or the like. 
     The height (absolute height) of the X-ray detector  440  from the floor is changed with the movement of the upper column  412  on the lower column  414  and the movement of the carriage  420  on the upper column  412 . An encoder  910  is provided at the base section of the lower column  414  in order to detect the absolute height of the X-ray detector  440 . The rotator of the encoder  910  is coupled to the carriage  420  via a non-expansion wire, not illustrated, whose extension and reel-up are possible. 
     The height detection signal of the encoder  910  is inputted to the operator console  600 . Thus, the operator console  600  can recognize the absolute height of the X-ray detector  440 . The encoder  901  is one example of an encoder according to the present invention. 
     Many widely different embodiments of the invention may be configured without departing from the spirit and the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.