Radiation irradiation device

Provided is a radiation irradiation device that can restrict movement of an arm part during device movement without providing a mechanism that becomes a user's obstacle. The radiation irradiation device includes a radiation generation unit that generates radiation; an arm part having one end to which the radiation generation unit is attached; a support member having one end to which the other end of the arm part is connected so as to be rotationally movable; a body part to which the other end of the support member is connected; a leg part that is provided on a bottom surface of the body part and is capable of traveling on a device placement surface; and an arm locking part that restricts the rotational movement of the arm part. The arm locking part is provided inside the arm part.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a radiation irradiation device having an arm part provided with a radiation source.

2. Description of the Related Art

In the related art, portable radiation irradiation devices used in a case where a patient's radiographic image is captured in operating rooms, examination rooms, or patients rooms have been suggested variously (refer to JP2014-73322A, JP2014-110872A, and JP2015-83113A).

The portable radiation irradiation devices basically include a leg part enabled to travel by wheels, a body part that houses a control unit including a battery for driving a radiation source, an electric circuit related to the driving of the radiation source, and the like and is held on the leg part, and an arm part connected to the body part, and are configured by attaching the radiation source to a tip of the arm part.

In a case where such radiation irradiation devices are used, a radiation irradiation device is first moved to the vicinity of a patient's bed. Next, the radiation source is moved to a desired position by extending the arm part, and a radiation detector is moved to a desired position behind a subject. In this state, the subject is irradiated with radiation by driving the radiation source, and a radiographic image of the subject is acquired by detecting the radiation transmitted through the subject using the radiation detector.

Meanwhile, in a case where the radiation irradiation device is moved, a state where the arm part is folded and the radiation source is housed is brought about. In this case, since there is a concern that the device may be damaged in a case where the arm part provided with the heavy radiation source vibrates, it is necessary to restrict movement of the arm part such that the arm part does not move.

Thus, for example, JP2014-73322A suggests a method of providing an outer peripheral surface of the folded arm part and a pillar at a position that faces the outer peripheral surface of the arm part in a case where the arm part is folded with connecting parts respectively and restricting movement of the arm part by connecting these connecting parts to each other.

SUMMARY OF THE INVENTION

However, in a case where a connecting part for locking the arm part is exposed as described in JP2014-73322A, there is a case where the connecting part may hit a user and become an obstacle.

An object of the invention is to provide a radiation irradiation device that can restrict movement of the arm part during device movement, without providing a mechanism that becomes a user's obstacle, in view of the above problems.

A radiation irradiation device of the invention comprises a radiation generation unit that generates radiation; an arm part having one end to which the radiation generation unit is attached; a support member having one end to which the other end of the arm part is connected so as to be rotationally movable; a body part to which the other end of the support member is connected; a leg part that is provided on a bottom surface of the body part and is capable of traveling on a device placement surface; and an arm locking part that restricts the rotational movement of the arm part. The arm locking part is provided inside the arm part.

Here, the expression “the arm locking part is provided inside the arm part” means that all constituent elements of the arm locking part may not be necessarily provided within the arm part and some constituent elements may be provided inside the support member.

Additionally, in the radiation irradiation device of the above invention, an arm unlocking part that releases the restriction by the arm locking part may be provided at the arm part.

Additionally, in the radiation irradiation device of the above invention, the arm unlocking part may be provided closer to the radiation generation unit side than a center in an extension direction of the arm part.

Additionally, in the radiation irradiation device of the above invention, the arm unlocking part may have a movable part that moves in a direction parallel to the extension direction of the arm part, and the restriction by the arm locking part may be released by the movement of the movable part.

Additionally, in the radiation irradiation device of the above invention, the arm unlocking part may release the restriction by the arm locking part depending on the movement of the movable part to the radiation generation unit side.

Additionally, in the radiation irradiation device of the above invention, the arm unlocking part may release the restriction by the arm locking part depending on the movement of the movable part to the support member side.

Additionally, in the radiation irradiation device of the above invention, the movable part may be a plate-shaped member or a tubular member that slides in the extension direction of the arm part.

Additionally, in the radiation irradiation device of the above invention, the arm locking part may restrict the rotational movement of the arm part, using a locking pin, and a locking part to which the locking pin is locked, and the arm unlocking part may release the locking performed by the locking part as the locking pin is moved by the movement of the movable part.

Additionally, in the radiation irradiation device of the above invention, the arm part may move rotationally only around one axis.

Additionally, in the radiation irradiation device of the above invention, the support member may be configured to be rotatable with an axis passing through a center of a connecting portion of the support member to the body part and extending in a vertical direction as a rotational axis.

Additionally, in the radiation irradiation device of the above invention, a support member locking part that restricts the rotation of the support member may be provided.

Additionally, in the radiation irradiation device of the above invention, the support member locking part may restrict the rotation in a case where the support member is located at a center of a rotational angle.

Additionally, in the radiation irradiation device of the above invention, the support member locking part may restrict the rotation of the support member only in a case where the rotational movement of the arm part is restricted using the arm locking part.

Additionally, in the radiation irradiation device of the above invention, the support member locking part may release the restriction of the rotation of the support member in an interlocking manner with the rotational movement of the arm part.

According to the radiation irradiation device of the invention, since the arm locking part that restricts the rotational movement of the arm part is provided inside the arm part, the movement of the arm part during device movement, can be restricted without providing a mechanism that becomes a user's obstacle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a radiation irradiation device of an embodiment of the invention will be described in detail, referring to the drawings.FIG. 1is a perspective view illustrating the entire shape of the radiation irradiation device of the present embodiment in a case where the device is not used, andFIG. 2is a side view illustrating the state of the radiation irradiation device of the present embodiment in a case where the device is used. In addition, in the following, an upper side and a lower side in the vertical direction in a state where the radiation irradiation device is placed, for example, a device placement surface, such as a floor of a medical institution, are referred to as “up” and “down”, respectively, and a direction perpendicular to the vertical direction in the same state is referred to as a “horizontal” direction. Additionally, in the views to be described below, the vertical direction is defined as a z direction, a right and left direction of the radiation irradiation device is defined as an x direction, and a forward-backward direction of the radiation irradiation device is defined as a y direction. In addition, the front herein means a side toward which an arm part is extended from a body part of the radiation irradiation device in a case where the device is used.

As illustrated inFIGS. 1 and 2, a radiation irradiation device1of the present embodiment includes a leg part10, a body part20, a support member30, an arm part40, and a radiation generation unit50.

The leg part10is capable of traveling on a device placement surface2, and includes a plate-shaped pedestal part11on which the body part20is placed, and a foot arm part12that extends from the pedestal part11toward the front.FIG. 3is a view of the leg part10as seen from below. As illustrated inFIG. 3, the foot arm part12is formed in a V shape that widens in the right and left direction toward the front.

The leg part10includes first casters10aand second casters10b. The first casters10aare respectively provided on bottom surfaces of two tip parts12aat the front of the foot arm part12, and second casters10bare respectively provided on bottom surfaces of two corners at the rear of the pedestal part11. By forming the foot arm part12in a V shape as described above, for example, as compared to a case where the entire leg part10is formed in a rectangular shape, an edge part of the leg part does not easily collide against its surrounding obstacle in a case where the leg part10is rotated. Thus, handling can be made easy. Additionally, weight reduction can also be achieved.

Additionally, as illustrated inFIG. 2, the foot arm part12is formed such that the thickness of the two front tip parts12ain the vertical direction is smaller than the thickness of a V-shaped root part12bin the vertical direction. In this way, by making the thickness of the two front tip parts12aof the foot arm part12small, it is possible to make the two tip parts12aeasier to enter a location under a bed where a subject is sleeping, or the like, and it is possible to use the device in a narrower space. In addition, the V-shaped root part means a portion where the legs that widen in the right and left direction toward the front join together at the rear side.

Each first caster10ahas a shaft that extends in the upward-downward direction, and is attached to a bottom surface of the foot arm part12such that a rotating shaft of a wheel is revolvable within a horizontal plane about the shaft of the first caster. Additionally, each second caster10balso has a shaft that extends in the upward-downward direction, and is attached to a bottom surface of the pedestal part11such that a rotating shaft of a wheel is revolvable within the horizontal plane about the shaft of the second caster. In addition, the rotating shaft of each wheel herein is a rotating shaft in a case where the wheel rotates and travels. The leg part10is configured so as to be capable of traveling in a certain direction on the device placement surface2by the first casters10aand the second casters10b.

Additionally, as illustrated inFIG. 1, a pedal part13is provided at the rear of the leg part10. The pedal part13is constituted of two pedals of a first pedal13aand a second pedal13b. The first pedal13ais a pedal for bringing the second casters10binto a non-revolvable state. As a user steps on the first pedal13a, the second casters10bare configured so as to be locked in revolution by a locking mechanism and brought into the non-revolvable state.

Additionally, the second pedal13bis a pedal for bringing the second casters10binto a revolvable state from the non-revolvable state. As the user steps on the second pedal13b, the second casters10bare configured so as to be released from the locking by the locking mechanism and brought into the revolvable state again.

A well-known configuration can be used as the locking mechanism that locks the revolution of the second casters10b. For example, the revolution may be locked such that both sides of the wheels of the second casters10bare sandwiches by plate-shaped members, or the revolution may be locked by providing members that stop the rotation of shafts of the second casters10bthat extend in the upward-downward direction.

The body part20is placed on the pedestal part11of the leg part10, and includes a housing21. A control unit22that controls driving of the radiation irradiation device1and a charging part27are housed within the housing21.

The control unit22performs control regarding generation of radiation and irradiation with radiation, such as a tube current, irradiation time, and a tube voltage, in the radiation generation unit50, and control regarding acquisition of radiographic images, such as image processing of a radiographic image acquired by a radiation detector to be described below. The control unit22is configured of, for example, a computer in which a program for control is installed, exclusive hardware, or a combination of both.

The charging part27includes a battery, and charges the radiation detector held by a cradle25to be described below. In addition, the charging part27is connected to an external power source via a connector (not illustrated), and the battery is charged under the supply of electrical power from the external power source.

Additionally, a monitor23is attached to a surface21b(hereinafter referred to as a monitor installation surface21b) that faces a bottom surface of the body part20via a pillar-shaped connecting member23a.

The monitor23made of a liquid crystal panel or the like, and displays a radiographic image acquired by imaging of the subject, and various kinds of information required for the control of the radiation irradiation device1. Additionally, the monitor23includes a touch panel type input unit24, and receives input of various instructions required for the operation of the radiation irradiation device1. Specifically, input for setting of imaging conditions and input for imaging, that is, emission of radiation, is received. In addition, instead of the touch panel type input unit24, buttons for performing various operations may be included as the input unit.

Additionally, a body handle part26for pushing or pulling the radiation irradiation device1is attached to an upper side, in the vertical direction, of the monitor installation surface21bof the body part20. The body handle part26is provided so as to go around the housing21, and is configured so as to be capable of being held not only from a rear side of the radiation irradiation device1but also from a front side or a lateral side.FIG. 4is a view of the radiation irradiation device1as seen from the front. As illustrated inFIG. 4, the body handle part26is provided so as to go around to a front side of the body part20.FIG. 5is a view of the radiation irradiation device1as seen from the rear.

As illustrated inFIGS. 2 and 5, the connecting member23ais connected to the monitor installation surface21bon a lower side in the vertical direction with respect to the body handle part26, and the monitor23is provided such that an end part of the monitor23on the lower side in the vertical direction is located on an upper side in the vertical direction with respect to the body handle part26. By configuring the invention in this way, the user can view the monitor23without being disturbed by the body handle part26, and the visibility of the monitor23can be improved.

Additionally, the body part20is configured to be capable of housing the radiation detector on the surface thereof opposite to a side where the support member30is attached. As the radiation detector, a cassette type radiation detector including a housing is used. Specifically, for example, a radiation detector including a scintillator (fluorescent body) that converts incident radiation into visible light, a photoelectric conversion layer that converts the visible light into electrical signals, and a thin film transistor (TFT) active matrix substrate.

As illustrated inFIGS. 1 and 2, the housing21of the body part20has a flat surface21ainclined to the support member30side, on a surface opposite to a side where the support member30is attached, and the flat surface21ais provided with the cradle25.

An insertion port25afor inserting the radiation detector is formed in an upper surface of the cradle25. The insertion port25ahas an elongated shape of a size such that the radiation detector is fitted thereto. In the present embodiment, one end part of the radiation detector is inserted into the insertion port25a, the one end part is supported by the cradle25, and the radiation detector is held by the cradle25. In this case, a front surface of the radiation detector is directed to the flat surface21aside.

A connector25bis attached to a bottom part of the cradle25. The connector25bis electrically connected to the connector of the radiation detector in a case where the radiation detector is held by the cradle25. The connector25bis electrically connected to the charging part27. The charging part27charges the radiation detector via the connector25b. In addition, the charging part27is connected to an external power source via a connector (not illustrated), and the battery is charged under the supply of electrical power from the external power source.

The radiation generation unit50is configured such that a radiation source, a collimator for narrowing the irradiation range of radiation, and the like is housed within a housing51. The radiation source is constituted of, for example, an X-ray tube, a booster circuit, and cooling means for cooling the X-ray tube, and the like. Emission of the radiation from the radiation source of the radiation generation unit50is performed depending on an instruction from an input unit24in the monitor23by an operator.

An L-shaped radiation source attachment part32is provided at a tip (one end) of the arm part40. The radiation generation unit50is attached to the one end of the arm part40via the radiation source attachment part32. The radiation generation unit50is connected to the radiation source attachment part32so as to be rotationally movable with an axis AX2as a rotational movement axis. The rotational movement axis AX2is an axis that extends in the right and left direction (x direction). In addition, the radiation source attachment part32holds the radiation generation unit50such that the radiation generation unit50moves rotationally via a friction mechanism. For this reason, the radiation generation unit50is rotationally movable by applying a certain degree of strong external force, and maintains a relative angle with respect to the arm part40without moving rotationally unless an external force is applied.

In addition, the rotational movement of the radiation generation unit50may be fixed by a well-known locking mechanism to the rotational movement position.

One end of the support member30is connected to the other end of the arm part40. The arm part40is connected to the support member30so as to be rotationally movable with an axis AX1as a rotational movement axis. The rotational movement axis AX1is an axis that extends in the right and left direction (x direction). The arm part40moves rotationally in a direction of arrow A illustrated inFIG. 2such that an angle formed with the support member30is changed about the rotational movement axis AX1. That is, the arm part40moves rotationally only around one axis (the rotational movement axis AX1) that extends in the right and left direction. In the present embodiment, as described above, the orientation of the arm part40can be freely changed together with the body part20by the revolution of the first casters10aand the second casters10b. Thus, the degree of freedom of rotation of the arm part40can be lowered, and a simpler configuration can be adopted.

A rotational movement part31having the rotational movement axis AX1holds the arm part40such that the arm part40moves rotationally via the friction mechanism. For this reason, the arm part40is rotationally movable by applying a certain degree of strong external force, does not move rotationally unless an external force is not applied, and maintains a relative angle with respect to the support member30.

An arm locking part60that restricts the rotational movement of the arm part40is provided inside the arm part40(inside the rotational movement part31). The arm locking part60restricts the rotational movement of the arm part40in a case where the arm part40is folded and brought into a non-use state, as illustrated inFIG. 1. Hereinafter, the configuration of the arm locking part60will be described in detail.FIG. 6is an internal structure view of the arm part40seen from a direction of arrow B in a state where the arm part40is extended as illustrated inFIG. 2. Additionally, althoughFIG. 7is a view of the arm locking part60illustrated inFIG. 6as seen from a direction of arrow C, and is a view illustrating the state of the arm locking part60in a case where being brought into the state where the arm part40is folded as illustrated inFIG. 1.

As illustrated inFIG. 6, the arm part40includes a tubular arm part body40athat has the radiation generation unit50attached to a tip thereof, and a locking part housing40bthat has the arm part body40aattached thereto and has a space40cwhere the arm locking part60is housed.

The arm locking part60housed inside the locking part housing40bincludes a locking pin61that extends in a direction (x direction) orthogonal to an extension direction of the arm part body40a, a locking spring part62that slides the locking pin61in the x direction, and a first plate member63and a second plate member64.

The first plate member63and the second plate member64are provided at an attachment member34, and the attachment member34is fixed to the support member30. That is, the first plate member63and the second plate member64are fixed to the support member30via the attachment member34.

Although the locking pin61is biased toward the first and second plate members63and64side by the locking spring part62, the locking pin61is reciprocated and moved in a direction of arrow D illustrated inFIG. 6by being pulled by a direction opposite to a direction in which the locking pin61is biased by a wire76(to be described below) attached to the locking pin61.

The first plate member63is a plate member formed in a teardrop type as illustrated inFIG. 7, and is provided to be fixed to the support member30via the attachment member34as described above. A first hole63aand a second hole63bare formed in the first plate member63. As illustrated inFIG. 7, a tip of the locking pin61is located in the second hole63bof the first plate member63in a state where the arm part40is folded, and the tip of the locking pin61moves inside the first hole63aformed in an arc along the arc in a case where the locking pin61is shifted from the state where the arm part40is folded to a state where the locking pin61is extended. In addition, the arm part40is extended by rotationally moving around a rotational movement shaft33illustrated inFIG. 7. InFIG. 6, although the rotational movement shaft33is not illustrated, the rotational movement shaft33is disposed at a position illustrated by a dotted line inFIG. 6, and both end parts thereof are fixed to the support member30.

The second plate member64(equivalent to the locking part) is provided on the surface of the first plate member63. The second plate member64is a plate member formed in a fan shape having a protrusion as illustrated inFIG. 7, and is provided to be fixed the surface of the first plate member63. The first hole63aand the second hole63bformed in the first plate member63are divided by the protrusion of the second plate member64. Thus, as the tip of the locking pin61inserted into the second hole63babuts against and is locked to the protrusion of the second plate member64, the movement of the locking pin61is restricted and thereby the movement of the arm part40is restricted. That is, the position of the arm part40is fixed in a state where the arm part40is folded as illustrated inFIG. 1.

In a case where the arm part40is unlocked in a case where the device is used, the locking pin61moves in the direction opposite to the biasing direction of the locking spring part62by being pulled by the wire76as described above, the second plate member64is unlocked by the tip of the locking pin61slipping out of the second hole63b, and thereby, the arm part40is unlocked. The tip of the locking pin61is inserted into the first hole63a, and the tip of the locking pin61moves within the first hole63atogether with the movement of the arm part40.

Next, the arm unlocking part70including the above-described wire76will be described. The arm unlocking part70includes a movable part71that moves in a direction parallel to the extension direction of the arm part40, a wire connecting member73that is connected to the movable part71via a pillar part72and has the wire76connected thereto, a releasing spring part74that biases the wire connecting member73toward the arm locking part60side, a fixing member75that fixes the releasing spring part74, the wire76having one end connected to the wire connecting member73and the other end connected to the locking pin61, and two pulleys77and78.

As illustrated inFIG. 8, the movable part71is a plate-shaped member, and the pillar part72connected to the above-described wire connecting member73is formed on the surface of the plate-shaped member. As illustrated inFIG. 9, a hole40dthat extends in the extension direction of the arm part body40ais formed in the arm part body40a. Thus, the pillar part72of the movable part71is inserted into the hole40d, and the movable part71is installed on an outer surface of the arm part body40a. The pillar part72inserted into the hole40dof the arm part body40ais connected to the wire connecting member73installed within the arm part body40a, and thereby, the movable part71and the wire connecting member73are connected together with a wall part of the arm part body40asandwiched therebetween.

In addition, in the present embodiment, the movable part71is formed in a flat plate shape. However, the invention is not limited to this, and the movable part71may be formed in a tubular shape. The shape of the movable part71may be combined with the shape of the arm part body40a. For example, in a case where the arm part body40ais formed in a cylindrical shape, a cross-section of the movable part71may be formed in a circular-arc plate shape or may be formed in a cylindrical shape. In a case where the movable part71is formed in a tubular shape, it is more preferable because the movable part71is easily held in a case where the user moves the movable part71.

The movable part71moves in the extension direction of the arm part40along an outer surface of the arm part40as the user applies an external force. The wire connecting member73moves in the extension direction of the arm part40by the movement of the movable part71. The wire connecting member73is configured to move in the same direction as the user holds the movable part71to move the movable part71toward the radiation generation unit50side, and to return in the opposite direction (toward the arm locking part60side) by the biasing of the releasing spring part74as the user lifts his/her hand from the movable part71. That is, the wire connecting member73is configured so as to reciprocally move in a direction of arrow E illustrated inFIG. 6.

In a case where the wire connecting member73has moved toward the radiation generation unit50side, the wire76with having one end connected to the wire connecting member73is pulled toward the radiation generation unit50side together with this movement. The other end of the wire76is connected to the locking pin61such that an extension direction thereof is changed to a direction parallel to the locking pin61by the two pulleys77and78. In a case where the wire76is pulled toward the radiation generation unit50side as described above, the locking pin61is pulled by the wire76and moves toward a side opposite to the first and second plate members63and64side, and the locking pin61is unlocked.

In a case where the movable part71and the wire connecting member73has moved toward the side opposite to the radiation generation unit50side as the user lifts his/her hand from the movable part71, the locking pin61moves toward the first and second plate members63and64side by the biasing of the locking spring part62. In a case where the tip of the locking pin61is inserted into the first hole63aas described above, the arm part40is unlocked and the extension of the arm part40is allowed.

In addition, it is desirable that a tip part of the locking pin61on the first and second plate members63and64side are formed in a tapered shape, or as illustrated inFIG. 6, an end surface is an inclined surface having a gradient that is not perpendicular to a side surface of the locking pin61. By configuring the invention in this way, in a case where the arm part40is shifted from a movable state to a locked state, that is, in a case where the tip part of the locking pin61is moved from the first hole63aof the first plate member63to the second hole63bthereof, the inclined surface of the tip part of the locking pin61can be moved while sliding on the protrusion of the second plate member64. Thus, the locking pin61can be moved toward the locking spring part62side without the user moving the movable part71in an unlocking direction (radiation generation unit50side). That is, the arm part40can be automatically brought into the locked state simply by the user folding the arm part40in the non-use state. In addition, in a case where the inclined surface having a gradient is formed at the tip part of the locking pin61, the inclined surface and the protrusion of the second plate member64are configured so as to face each other and are in contact with each other.

It is preferable that the movable part71is provided closer to the radiation generation unit50side than the center of the arm part40in the extension direction, and it is more preferable to provide the movable part71is provided at an end part of the arm part body40ain the vicinity of the radiation generation unit50. By providing the movable part71at such a position, the unlocking operation of the arm part40by the user and the operation of extending the arm part40can be performed through the series of operations without moving the user's hand.

Additionally, in the present embodiment, the arm part40is unlocked by moving the movable part71toward the radiation generation unit50side. However, contrary to this, the arm part40may be unlocked by moving the movable part71toward the support member30side (arm locking part60side). In this case, the unlocking direction may be changed to the support member30side by adding one pulley into the locking part housing40band folding back the orientation of the wire76. In this way, since the user draws the movable part71close to the user side at the time of unlocking by changing the unlocking direction to the support member30side, it becomes easier to operate the device.

The above is the description of the arm locking part60and the arm unlocking part70. In addition, the constituent elements of the arm locking part60and the arm unlocking part70are not limited to the above-described ones, and these constituent elements may be configured using a combination of a belt, a gear and a rack, a pinion, and the like as long as a mechanism that moves the locking pin61is provided similarly to the above.

In addition, in the present embodiment, the arm part40does not have an extendable and retractable configuration, and is configured to be incapable of being extended and retracted. In the present embodiment, as described above, the orientation of the arm part40can be freely changed together with the body part20by the revolution of the first casters10aand the second casters10b. Thus, it is not necessary to provide a configuration in which the arm part40is extended and retracted, and a simpler configuration can be adopted. However, the invention is not limited to such a configuration and a configuration in which the arm part40is extendable and retractable may be adopted.

The other end of the support member30is connected to the surface of the body part20on the front side. The support member30is configured to be rotatable with respect to the body part20. Specifically, as illustrated inFIG. 1, the support member30may be configured so as to be rotatable in a direction of arrow F, with an axis passing through the center of the connecting portion of the support member30to the body part20and extending in the vertical direction (z direction) as a rotational axis AX3.

FIG. 10is a view illustrating an example of a maximum rotational angle of the support member30, and is a view of the radiation irradiation device1as seen from the bottom. As illustrated inFIG. 10, it is desirable that a maximum rotational angle θ1of the support member30is an angle at which the position, in the right and left direction (x direction), of the radiation generation unit50in a case where the arm part40is extended to the maximum toward the front becomes the same position as the positions of the front first casters10ain the right and left direction (x direction). By setting the maximum rotational angle θ1in this way, the weight balance of the entire device can be prevented from collapsing in a case where the arm part40is extended. Additionally, since the support member30is not vainly rotated in a case where the radiation generation unit50is moved to a position immediately above a predetermined position of the subject on a bed, alignment of the irradiation position with respect to the subject can be performed easily.

Additionally, the maximum rotational angle of the support member30is not limited to the angle illustrated inFIG. 10. For example, the support member30may be configured to be rotatable up to an angle illustrated inFIG. 11. That is, an angle at which an axis extending in the length direction of the support member30and the arm part40comes to a position on a straight line connecting the rotational axis AX3of the support member30and the centers of the front first casters10ato each other may be a maximum rotational angle θ2.

The maximum rotational angle of the support member30is preferably ±20° and more preferably 15° more preferably with respect to a central position CP of the maximum rotational angle.

Additionally, in the present embodiment, the support member30is configured such that the rotation thereof is locked at the central position CP of the maximum rotational angle. By locking the rotation of the support member30at the central position CP of the maximum rotational angle in this way, the support member30and the arm part40can be disposed at a central position of the radiation irradiation device1in the right and left direction, for example, in a case where the radiation irradiation device1is moved, weight balance can be maintained and straightness can be improved. Additionally, the arm part40can be prevented from colliding against surrounding things.

Hereinafter, a support member locking part90that locks the rotation of the support member30will be described in detail, referring toFIGS. 12 to 14.

First, a rotating mechanism35is provided at the connecting portion of the support member30to the body part20. The support member30is configured to be rotatable up to the above-described maximum rotational angle with the rotational axis AX3as a center by the rotating mechanism35. The rotating mechanism35holds a support member body30asuch that the support member body30arotates via a friction mechanism. Hence, the support member30including the support member body30ais rotatable by a certain degree of strong external force being applied thereto, and maintains a relative angle with respect to the body part20with being rotated unless an external force is applied.

The above-described support member locking part90is further provided. Thus, in a case where the rotation is locked by the support member locking part90, the support member30is configured so as not to rotate even in a case where an external force is applied.

The support member locking part90includes a rotation restricting plate36and a locking shaft37.FIG. 13is a top view of the rotation restricting plate36. As illustrated inFIG. 13, the rotation restricting plate36is provided with a first opening36aand a second opening36b. The above-described rotating mechanism35is provided within the second opening36bof the rotation restricting plate36. As one end37aof the locking shaft37provided within the support member30is inserted into the first opening36aof the rotation restricting plate36, and the one end37aof the locking shaft37is engaged with an inner wall of the first opening36a, the rotation of the support member30is locked. The first opening36aof the rotation restricting plate36is formed at a position locked in a case where the support member30is located at the central position CP (refer toFIGS. 10 and 11) of the maximum rotational angle as described above.

The locking shaft37is configured to be movable in a direction of arrow Al and in a direction of arrow A2that are illustrated inFIG. 12. In a case where the locking shaft37has moved up to a position illustrated by a dotted line ofFIG. 12, and thereby, the one end37aof the locking shaft37has slipped out of the first opening36a, the support member30is unlocked. Specifically, the support member locking part90includes a wire91, and one end91aof the wire91is connected to the other end37bof the locking shaft37. By pulling the wire91in the direction of arrow A1, the locking shaft37moves in the direction of arrow A1, and the one end37aof the locking shaft37slips out of the first opening36aof the rotation restricting plate36.

Moreover, the support member locking part90includes two spring members38. One end of each of the two spring members38is connected to a fixing member39fixed to a housing of the support member30, or the like, and the other end of each of the two spring members38is connected to a flange37cprovided to be fixed to the locking shaft37. The two spring members38biases the locking shaft37in the arrow A2direction (toward the rotation restricting plate36side), and move the locking shaft37in the direction of arrow A2in a case where the tension of the locking shaft37in the direction of arrow Al by the wire91is loosened.

The support member locking part90restricts the rotation of the support member30only in a case where the rotational movement of the arm part40is locked by the above-described arm locking part60. Specifically, as illustrated inFIG. 14, the other end91bof the wire91is connected to a rotating plate41via three pulleys92,93, and94. The rotating plate41is connected to the arm part40, and rotates with the rotational movement axis AX1as an axis together with the rotational movement of the arm part40.

Hence, as the rotating plate41rotates in a direction of arrow B1, the wire91is pulled in the direction of arrow Al illustrated inFIG. 12, and as the rotating plate41rotates in a direction of arrow B2, the tension of the wire91in the direction of arrow A1is loosened.

As illustrated inFIGS. 1 and 7, the wire91is set to have such a length that the one end37aof the locking shaft37is inserted into the first opening36aof the rotation restricting plate36, in a state where the arm part40is folded (that is, in a state where the rotational movement of the arm part40is locked), and is set to have such a length that the one end37aof the locking shaft37slips out of the first opening36aof the rotation restricting plate36, in a case where the arm part40is unlocked and the arm part40moves rotationally. Accordingly, the rotation of the support member30can be restricted only in a case where the rotational movement of the arm part40is locked by the arm locking part60as described above. By configuring the invention in this way, the rotation of the support member30can be unlocked in an interlocking manner with the rotational movement of the arm part40, and the operability of the device can be improved.

In addition, in above description, the rotation of the support member30is unlocked in an interlocking with the rotational movement of the arm part40by connecting the other end91bof the wire91of the support member locking part90to the rotating plate41. However, the invention is not limited to this, and the other end91bof the wire91may be connected to the wire76of the arm unlocking part70. As a result, in a case where the user moves the movable part71of the arm unlocking part70, the wire91of the support member locking part90is pulled together with the wire76of the arm unlocking part70, and both the rotational movement of the arm part40and the rotation of the support member30can be unlocked. That is, the unlocking of the rotational movement of the arm part40and the unlocking of the rotation of the support member30can be interlocked with each other.

In addition, in the above description, in a case where the rotational movement of the arm part40is locked, the rotation of the support member30is locked as the one end37aof the locking shaft37is inserted into the first opening36aof the rotation restricting plate36. However, the method of locking the rotation of the support member30is not limited to this. For example, in a case where the rotating mechanism35of the support member30is provided with a friction brake mechanism having rubber or the like and the rotational movement of the arm part40is locked, the rotation of the support member30may be locked by the friction brake mechanism.

Additionally, in the above description, the first opening36ais provided on the rotation restricting plate36side and the locking shaft37is fitted to the first opening. However, the arrangement may be reversed, that is, a protrusion may be provided on the rotation restricting plate36side, and a member having a recess fitted to the protrusion may be provided on the locking shaft37side. The above is description regarding the support member locking part90.

Additionally, in the present embodiment, the support member30is configured to be rotatable with respect to the body part20. However, the invention is not limited to this, and the support member30may be provided to be fixed to the body part20, and may be configured to be non-rotatable. In this case, a simpler configuration can be adopted.

Additionally, as illustrated inFIG. 2, the support member30of the present embodiment is provided such that the inclination θ of the extension direction thereof with respect to the vertical direction become 30 degrees or more and 10 degrees or less. By setting the inclination θ of the support member30to 10 degrees or more, the user's front visibility can be secured. Additionally, by setting the inclination θ of the support member30to 30 degrees or less, the arm part40can be folded downward and the radiation generation unit50can be housed. Additionally, in a case where the radiation irradiation device1is used, a source image receptor distance (SID) can be secured.

In addition, the extension direction of the support member30means an axial direction thereof in a case where the support member30is formed linearly. Additionally, the extension direction means a direction in which a straight line connecting the centers of both end parts of the support member30together extends in a case where the support member30is formed in shapes, such as an arc, other than the straight line.

In the present embodiment, in a case where the subject is imaged, as illustrated inFIG. 2, the radiation detector80is disposed under the subject H that lies on ones' back on a bed3. As the user rotationally moves the arm part40around the rotational movement axis AX1in an illustrated counterclockwise direction from an initial position of the arm part40illustrated inFIG. 1, the radiation generation unit50is moved to a target position immediately above the subject H, as illustrated inFIG. 2.

The radiographic image of the subject H can be acquired by driving the radiation generation unit50according to an instruction from the input unit24to irradiate the subject H with radiation and detecting the radiation transmitted through the subject H, using the radiation detector80, after the radiation generation unit50is moved to the target position. In addition, the radiation detector80and the radiation irradiation device1are connected together with or without wires. Accordingly, the radiographic image of the subject H acquired by the radiation detector80is directly input to the radiation irradiation device1.

EXPLANATION OF REFERENCES

1: radiation irradiation device

10: leg part

10a: first caster

11: pedestal part

12: foot arm part

13: pedal part

20: body part

22: control unit

24: input unit

26: body handle part

27: charging part

30: support member

30a: support member body

31: rotational movement part

32: radiation source attachment part

33: rotational movement shaft

34: attachment member

36: rotation restricting plate

36a: first opening

36b: second opening

37a: one end of locking shaft

37b: other end of locking shaft

38: spring member

39: fixing member

40: arm part

40a: arm part body

40b: locking part housing

50: radiation generation unit

60: arm locking part

62: locking spring part

63: first plate member

63a: first hole

63b: second hole

64: second plate member

70: unlocking part

71: movable part

72: pillar part

73: wire connecting member

74: releasing spring part

75: fixing member

90: support member locking part

91a: one end of wire

91b: other end of wire

CP: central position of maximum rotational angle