Patent Description:
<CIT> discloses an X-ray diagnostic apparatus for mammography comprising: X-ray exposure means for exposing X-rays (for example, corresponding to a radiation source), an X-ray plane detector for detecting X-rays incident on a detection surface, a compression plate for compressing and fixing a breast, and projection means for projection a reference image which is referred to in a case of fixing the breast by the compression plate onto the compression plate or the detection surface. The technology described in <CIT> discloses that the projection means (for example, a projector) is used to project the reference image (for example, a skin line) for positioning the breast onto the compression plate or the detection surface. The projection means is provided in an arm accommodating an X-ray tube.

In the mammography apparatus disclosed in <CIT>, for example, a cooling fan is provided in an arm accommodating a radiation source. The cooling fan cools the radiation source with air sucked from the outside and discharges the air that has passed through the radiation source to the outside through an exhaust port. In such a mammography apparatus, a method of cooling a projector accommodated in the arm has been studied. For example, a cooling method is conceivable in which the projector is cooled by the air sucked from the outside in the same manner as the radiation source, and the air that has passed through the projector is discharged to the outside through the same exhaust port.

However, in this cooling method, a cooling efficiency of the projector may be decreased. This is because a size of the radiation source is larger than that of the projector, so that a flow rate of the air passing through the radiation source needs to be larger than that of the projector. Therefore, in a case where the air directed from the radiation source to the exhaust port and the air directed from the projector to the exhaust port are merged in front of the exhaust port and then discharged from the exhaust port, a flow of the air cooling the projector is obstructed and the cooling efficiency of the projector may be decreased.

<CIT> and <CIT> do not describe a configuration for cooling the radiation source and the projector.

The technology of the present disclosure provides a mammography apparatus capable of efficiently cooling a projector.

According to a first aspect, there is provided a mammography apparatus comprising: an arm that accommodates a radiation source emitting radiation toward a breast and is supported by a stand; a first cooling fan that is disposed on a stand side with respect to the radiation source in the arm, sucks air from an outside of the arm, and discharges air that has cooled the radiation source from a first exhaust port provided on the stand side with respect to the radiation source; a projector that is disposed in the arm and projects information; a second cooling fan that is disposed between the projector and the first exhaust port in the arm, sucks a part of air directed from the first cooling fan to the first exhaust port, blows the sucked air toward the projector to cool the projector, and has a flow rate smaller than that of the first cooling fan; and a second exhaust port that is provided separately from the first exhaust port and through which air that has cooled the projector is discharged.

In an embodiment, the mammography apparatus further comprises: a first flow path in which the first cooling fan is disposed and that is directed from the first cooling fan to the first exhaust port; and a second flow path that is directed from a branch portion branching from the first flow path to the second exhaust port between the first cooling fan and the first exhaust port and in which the second cooling fan and the projector are disposed, in which a partition is provided between the first flow path and the second flow path except for the branch portion.

In an embodiment, a first distance from an end surface of the radiation source on a first cooling fan side to the second cooling fan via the branch portion is longer than a second distance from the end surface to the first exhaust port.

In an embodiment, a light source of the projector is disposed on a second cooling fan side with respect to the second exhaust port.

In an embodiment, an emission port through which projection light is emitted from the projector also serves as the second exhaust port.

In an embodiment, the projector is disposed on a radiation source side with respect to the first cooling fan and the second cooling fan, and in a case where the first flow path and the second flow path are viewed as a whole, the first flow path and the second flow path form a V-shape with the branch portion as an apex.

The technology of the present disclosure can provide a mammography apparatus capable of efficiently cooling the projector.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

In the following description, for convenience of explanation, a height direction, a width direction, and a front-rear direction (also referred to as a depth direction) of the mammography apparatus <NUM> are indicated by three arrows X, Y, and Z. First, the height direction is indicated by the arrow Z, an arrow Z direction pointed by the arrow Z is an upward direction of the mammography apparatus <NUM>, and an opposite direction of the upward direction is a downward direction. The height direction is a vertical direction. The width direction is indicated by the arrow X orthogonal to the arrow Z, a direction pointed by the arrow X is a right direction of the mammography apparatus <NUM>, and an opposite direction of the right direction is a left direction. The front-rear direction is indicated by the arrow Y orthogonal to the arrow Z and the arrow X, a direction pointed by the arrow Y is a front direction of the mammography apparatus <NUM>, and an opposite direction of the front direction is a rear direction. That is, in the mammography apparatus <NUM>, a stand <NUM> side is the rear direction, and an opposite side thereof on which a subject A stands (see <FIG>) is the front direction. In addition, in the following, expressions using sides such as an upper side, a lower side, a left side, a right side, a front side, and a rear side have the same meanings as the expressions using the directions.

In the present embodiment, a "vertical direction" refers not only to a perfect vertical direction but also to a vertical direction in the sense of including an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the concept of the technology of the present disclosure. The same applies to a "horizontal direction". The "horizontal direction" refers not only to a perfect horizontal direction but also to a horizontal direction in the sense of including an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the concept of the technology of the present disclosure.

As shown in <FIG> and <FIG>, the mammography apparatus <NUM> according to a first embodiment is a radiography apparatus that irradiates a breast M of the subject A to be examined with radiation and captures a radiographic image of the breast M. The radiation is X-rays as an example, but γ-rays may also be used. The subject A is located on the front side with respect to the mammography apparatus <NUM>. The mammography apparatus <NUM> is an example of a "mammography apparatus" according to the technology of the present disclosure.

The mammography apparatus <NUM> is connected to a console (not shown). The console has a setting function of setting the mammography apparatus <NUM> in accordance with an imaging order and a function of acquiring a radiographic image captured by the mammography apparatus <NUM> and displaying the acquired radiographic image. The console is communicably connected to an image database server (not shown) via a network (not shown) such as a local area network (LAN).

The mammography apparatus <NUM> includes a stand <NUM> and an arm <NUM>. The stand <NUM> includes a pedestal 20A that is provided on a floor of a radiography room and a support column 20B that extends from the pedestal 20A in a height direction. The arm <NUM> has a substantially C-shape as viewed from the left side and is connected to the support column 20B. Since the arm <NUM> is movable in a height direction with respect to the support column 20B, a height of the arm <NUM> can be adjusted according to a height of the subject A. The arm <NUM> is rotatable about a rotation axis perpendicular to the support column 20B. The stand <NUM> is an example of a "stand" according to the technology of the present disclosure. The arm <NUM> is an example of an "arm" according to the technology of the present disclosure.

The arm <NUM> is composed of a radiation source accommodation portion <NUM>, a main body portion <NUM>, and an imaging table <NUM>. A radiation source <NUM> is accommodated in the radiation source accommodation portion <NUM>. The radiation source accommodation portion <NUM> has, for example, a housing structure having a longitudinal direction in the horizontal direction (that is, a direction along the Y direction shown in <FIG>). The breast M of the subject A is placed on the imaging table <NUM>. A radiation detector <NUM> is accommodated in the imaging table <NUM>. The main body portion <NUM> integrally connects the radiation source accommodation portion <NUM> and the imaging table <NUM>. The main body portion <NUM> holds the radiation source accommodation portion <NUM> and the imaging table <NUM> at positions facing each other. Handrails <NUM> for the subject A to hold are provided on both sides of the main body portion <NUM>.

The radiation source <NUM> emits radiation toward the breast M placed on the imaging table <NUM>. The radiation source <NUM> is an example of a "radiation source" according to the technology of the present disclosure. The radiation emitted from the radiation source <NUM> is transmitted through the compression plate <NUM> and then is incident on the breast M. The radiation detector <NUM> detects the radiation transmitted through the breast M and outputs a radiographic image. The radiation detector <NUM> is referred to as a flat panel detector (FPD). The radiation detector <NUM> may be an indirect conversion type that includes a scintillator converting the radiation into visible light and converts the visible light emitted from the scintillator into an electric signal or a direct conversion type that directly converts the radiation into an electric signal.

An irradiation field limiter <NUM> is provided between the radiation source accommodation portion <NUM> and the imaging table <NUM>. The irradiation field limiter <NUM> is also referred to as a collimator and defines an irradiation field of the radiation to the imaging table <NUM>.

A face guard <NUM> is attached to the radiation source accommodation portion <NUM>. The face guard <NUM> is formed of or coated with a material not transmitting the radiation and protects a face of the subject A from the radiation.

The compression plate <NUM> is provided between the imaging table <NUM> and the irradiation field limiter <NUM> to sandwich the breast M with the imaging table <NUM> and compress the breast M. The compression plate <NUM> is formed of a material that transmits the radiation. The compression plate <NUM> is disposed at a position facing the imaging table <NUM>. In the present embodiment, the compression plate <NUM> has a box shape in which an upper surface side is open. The compression plate <NUM> may have other shapes such as a flat plate shape.

A drive mechanism <NUM> movably supports the compression plate <NUM> between the radiation source <NUM> and the imaging table <NUM>. Further, a movable portion <NUM> is disposed between the compression plate <NUM> and the drive mechanism <NUM>. The movable portion <NUM> is slidably held by a rail <NUM> provided in the drive mechanism <NUM>. The rail <NUM> extends in an up-down direction.

The compression plate <NUM> is attached to the movable portion <NUM>. The movable portion <NUM> moves in the up-down direction together with the compression plate <NUM> by the drive mechanism <NUM> described later. The up-down direction is functionally a direction in which the compression plate <NUM> moves toward the imaging table <NUM> (that is, the downward direction) and a direction in which the compression plate <NUM> moves away from the imaging table <NUM> (that is, the upward direction). As described above, the compression plate <NUM> is configured to be movable in such a manner that a distance from the imaging table <NUM> is changed.

A projector <NUM> is accommodated in the radiation source accommodation portion <NUM>. The projector <NUM> emits projection light L through an emission port <NUM>. The projector <NUM> projects an image toward an imaging surface 24A of the imaging table <NUM>. Here, the imaging surface 24A is a surface facing the radiation source <NUM> on the imaging table <NUM>. In addition, the projector <NUM> projects an image toward a surface facing the radiation source <NUM> on the compression plate <NUM>. Since the compression plate <NUM> of the present embodiment has a box shape, a bottom surface 30A of the box shape is a surface facing the radiation source <NUM>. The projector <NUM> projects an image toward the bottom surface 30A of the compression plate <NUM>. The projector <NUM> is an example of a "projector" according to the technology of the present disclosure.

The radiation source accommodation portion <NUM> accommodates a radiation source cooling fan <NUM> and a projector cooling fan <NUM>. The radiation source cooling fan <NUM> is a fan for cooling the radiation source <NUM>. The radiation source cooling fan <NUM> sucks air from the outside of the arm <NUM> and further exhausts the air to the outside of the arm <NUM>. Accordingly, an airflow F1 of the air passing through the radiation source is generated in the arm <NUM>. The projector cooling fan <NUM> is a fan for cooling the projector. The projector cooling fan <NUM> sucks a part of the air directed from the radiation source cooling fan <NUM> to the outside and blows the sucked air toward the projector <NUM>. As a result, an airflow F2 of the air passing through the projector <NUM> is generated in the arm <NUM>. The radiation source cooling fan <NUM> is an example of a "first cooling fan" according to the technology of the present disclosure, and the projector cooling fan <NUM> is an example of a "second cooling fan" according to the technology of the present disclosure.

As shown in <FIG>, in the mammography apparatus <NUM>, the projection light L is emitted from the projector <NUM> so that imaging condition information <NUM> is projected onto the compression plate <NUM>, and a skin line 24B is projected onto the imaging surface 24A.

Imaging conditions indicated by the imaging condition information <NUM> include a current compression pressure, compression thickness, or type of imaging technique for the breast M. Examples of the imaging technique include cranio-caudal (CC) imaging and medio-lateral (MLO) imaging. The imaging condition information <NUM> is an example of "information" according to the technology of the present disclosure.

In the bottom surface 30A of the compression plate <NUM>, a region <NUM> onto which the imaging condition information <NUM> is projected is subjected to a process of suppressing transmission of light (for example, blasting process). As a result, the projection light L representing the imaging condition information <NUM> is less likely to transmit through the compression plate <NUM>, and an amount of reflected light on the compression plate <NUM> increases, so that the imaging condition information <NUM> is clearly visible.

Portions of the compression plate <NUM> other than the region <NUM> are made of a material transparent to the projection light L. Therefore, the projection light L transmitted through the compression plate <NUM> is projected onto the imaging surface 24A. A skin line 24B indicating a contour of the breast M, which is an index for placing the breast M, is projected onto the imaging surface 24A. The skin line 24B is an example of "information" according to the technology of the present disclosure. In addition, instead of the skin line 24B or together with the skin line 24B, a mark indicating a position of a papilla of the breast M (for example, a mark of a cross having an intersection at the position of the papilla) may be projected onto the imaging surface 24A.

The breast M of the subject A is positioned on the imaging surface 24A of the imaging table <NUM> by a user. The breast M is compressed by the compression plate <NUM> in a state in which the breast M is positioned.

Here, an example of a form in which the imaging condition information <NUM> is projected onto the compression plate <NUM>, and the skin line 24B is displayed on the imaging surface 24A has been described, but the technology of the present disclosure is not limited thereto. For example, an aspect in which the imaging condition information <NUM> and the skin line 24B are displayed on the compression plate <NUM> may be employed.

As shown in <FIG>, the radiation source cooling fan <NUM> is disposed on the stand <NUM> side (that is, the rear side) with respect to the radiation source <NUM> in the horizontal direction (a direction along the Y direction shown in <FIG>). The radiation source cooling fan <NUM> sucks the air from the front side of the radiation source accommodation portion <NUM> and exhausts the air to the rear side of the radiation source accommodation portion <NUM>. Specifically, an air supply port <NUM> is provided on the front side of a top wall 22A of the radiation source accommodation portion <NUM>. Further, an exhaust port <NUM> is provided on the upper side of a rear wall 22B of the radiation source accommodation portion <NUM>. The radiation source cooling fan <NUM> sucks outside air from the air supply port <NUM> and exhausts the air toward the exhaust port <NUM>. The exhaust port <NUM> is an example of a "first exhaust port" according to the technology of the present disclosure.

The radiation source cooling fan <NUM> generates the airflow F1. The airflow F1 is a flow of air that enters into the radiation source accommodation portion <NUM> from the air supply port <NUM>, passes through an upper flow path <NUM> in the radiation source accommodation portion <NUM>, and is discharged to the outside from the exhaust port <NUM>. The radiation source <NUM> is provided below the air supply port <NUM>. As the airflow F1 hits the radiation source <NUM>, heat of the radiation source <NUM> is transferred to the airflow F1 and the radiation source <NUM> is cooled. The airflow F1 that has cooled the radiation source <NUM> is discharged toward the exhaust port <NUM> through the radiation source cooling fan <NUM>.

The projector cooling fan <NUM> is disposed between the exhaust port <NUM> and the projector <NUM> in the horizontal direction. The projector cooling fan <NUM> sucks a part of the airflow F1 discharged from the radiation source cooling fan <NUM> and directed to the exhaust port <NUM>, and blows the sucked airflow toward the projector <NUM>. The airflow F2 is generated by the projector cooling fan <NUM>. The airflow F2 is a flow of air in which a part of the airflow F1 is directed to the emission port <NUM> of the projector <NUM>. As the airflow F2 hits the projector <NUM>, heat of the projector <NUM> is transferred to the airflow F2 and the projector <NUM> is cooled. Here, in general, a temperature (for example, about <NUM>) of heat generated in the projector <NUM> mounted on the mammography apparatus <NUM> is higher than a temperature (for example, about <NUM>) of heat generated in the radiation source <NUM>. Therefore, even the air after cooling the radiation source <NUM> can cool the projector <NUM> because the air has a temperature lower than the temperature of the heat generated in the projector <NUM>.

The airflow F2 that has cooled the projector <NUM> is discharged from the emission port <NUM> of the projector <NUM>. In other words, the emission port <NUM> also serves as an opening through which the airflow F2 is discharged. The emission port <NUM> is an example of an "emission port" and a "second exhaust port" according to the technology of the present disclosure.

A flow rate of the projector cooling fan <NUM> is smaller than a flow rate of the radiation source cooling fan <NUM>. Here, the flow rate refers to a volume of air passing through the fan per unit time. In general, a size of the projector <NUM> mounted on the mammography apparatus <NUM> is smaller than a size of the radiation source <NUM>. As described above, the temperature of the radiation source <NUM> is lower than the temperature of the projector <NUM>. However, the size of the radiation source <NUM> is larger than the size of the projector <NUM>. Therefore, it is necessary to increase the flow rate of the radiation source cooling fan <NUM>, and the flow rate of the projector cooling fan <NUM> becomes relatively small. Referring to <FIG>, a flow rate of the airflow F2 is smaller than a flow rate of the airflow F1.

The upper flow path <NUM> and a lower flow path <NUM> are formed in the radiation source accommodation portion <NUM>. The upper flow path <NUM> and the lower flow path <NUM> are formed by dividing the inside of the radiation source accommodation portion <NUM> into upper and lower parts in the vertical direction by a partition plate <NUM>. The upper flow path <NUM> is a flow path formed on the upper side of the partition plate <NUM> in the radiation source accommodation portion <NUM>. The radiation source cooling fan <NUM> is disposed in the upper flow path <NUM>. The upper flow path <NUM> is a flow path directed at least from the radiation source cooling fan <NUM> to the exhaust port <NUM>. In an example shown in <FIG>, the upper flow path <NUM> guides the airflow F1 from the air supply port <NUM> to the exhaust port <NUM>. That is, the upper flow path <NUM> causes the airflow F1 to propagate in a predetermined path in the radiation source accommodation portion <NUM>, and prevents the airflow F1 from flowing into the other airflow F2. The upper flow path <NUM> is an example of a "first flow path" according to the technology of the present disclosure, and the lower flow path <NUM> is an example of a "second flow path" according to the technology of the present disclosure. Further, the partition plate <NUM> is an example of a "partition" according to the technology of the present disclosure.

The lower flow path <NUM> is a flow path formed on the lower side of the partition plate <NUM> in the radiation source accommodation portion <NUM>. The lower flow path <NUM> is a flow path directed from a branch portion <NUM> to the emission port <NUM>. The branch portion <NUM> is a region where the upper flow path <NUM> branches between the radiation source cooling fan <NUM> and the exhaust port <NUM>. In other words, the upper flow path <NUM> and the lower flow path <NUM> are partitioned by the partition plate <NUM> except for the branch portion <NUM>. The projector <NUM> and the projector cooling fan <NUM> are disposed in the lower flow path <NUM>. The lower flow path <NUM> guides the airflow F2 from the branch portion <NUM> to the emission port <NUM>. That is, the lower flow path <NUM> causes the airflow F2 to propagate in a predetermined path in the radiation source accommodation portion <NUM> and prevents the airflow F2 from flowing into the other airflow F1. The branch portion <NUM> is an example of a "branch portion" according to the technology of the present disclosure.

In a case where the upper flow path <NUM> and the lower flow path <NUM> are viewed from the side of the mammography apparatus <NUM> (that is, in case of being viewed from the X direction shown in <FIG>), the upper flow path <NUM> and the lower flow path <NUM> form a V-shape (that is, a shape of ">") with the branch portion <NUM> as an apex. That is, the lower flow path <NUM> is branched from the upper flow path <NUM> so as to be folded back at the branch portion <NUM>. Here, the projector <NUM> is disposed on the radiation source <NUM> side (that is, the front side) with respect to the radiation source cooling fan <NUM> and the projector cooling fan <NUM>. Thus, a distance from the radiation source cooling fan <NUM> to the projector <NUM> is ensured.

For example, the radiation source <NUM> includes a bulb 25A that generates radiation and a container 25B that accommodates the bulb 25A. The container 25B is an insulating container that accommodates the bulb 25A in a state in which a periphery of the bulb 25A is filled with insulating oil. In the container 25B, a distance from an end surface 25C (that is, a rear end surface 25C) of the container 25B on the radiation source cooling fan <NUM> side to the exhaust port <NUM> is defined as L1. Here, the distance L1 is the shortest distance along the upper flow path <NUM> from the rear end surface 25C to the exhaust port <NUM> in a case where the upper flow path <NUM> is viewed sideways. On the other hand, a distance from the rear end surface 25C to the branch portion <NUM> is defined as L2. Further, a distance from the branch portion <NUM> to the projector cooling fan <NUM> is defined as L3. The distance L2 is the shortest distance along the upper flow path <NUM> from the rear end surface 25C to the branch portion <NUM> in a case where the upper flow path <NUM> is viewed sideways. In addition, the distance L3 is the shortest distance along the lower flow path <NUM> from the branch portion <NUM> to the projector cooling fan <NUM> in a case where the lower flow path <NUM> is viewed sideways.

In this case, a sum of the distances L2 and the distance L3 is longer than the distance L1 (that is, L2 + L3 > L1). In this way, a distance from the rear end surface 25C of the radiation source <NUM> to the projector cooling fan <NUM> via the branch portion <NUM> is set to be longer than the distance from the rear end surface 25C to the exhaust port. Therefore, the distance from the radiation source cooling fan <NUM> to the projector <NUM> is ensured.

As shown in <FIG>, the projector <NUM> includes a display 14A, a projection optical system 14D, and a light source 14E. The display 14Aprojects an image displayed on an image display surface 14A1. Examples of the display 14A include a liquid crystal display (LCD). As is well known, the LCD comprises a plurality of liquid crystal cells corresponding to a plurality of pixels, and changes a transmission state of light from the light source 14E for each liquid crystal cell to perform optical modulation according to an image to be projected. In a case where the display 14A is the LCD, an arrangement surface on which the plurality of liquid crystal cells are two-dimensionally arranged corresponds to the image display surface 14A1. The projection optical system 14D includes a built-in optical system 14B and a mirror 14C. The built-in optical system 14B is an optical system including a lens 14B1. In addition, the mirror 14C reflects the projection light L emitted from the built-in optical system 14B to emit the projection light L to the compression plate <NUM> and the imaging surface 24A. The light source 14E emits the projection light L toward the display 14A. Further, a reflecting plate 14F is provided on a side of the light source 14E opposite to the display 14A, and the reflecting plate 14F reflects a part of the projection light L toward the display 14A. Accordingly, it is possible to increase a light quantity of the projection light L directed to the display 14A. The light source 14E is an example of a "light source" according to the technology of the present disclosure.

Although an example of a form in which the LCD is used as the display 14A has been described here, this is only an example. For example, a digital micromirror device (DMD) may be used as the display 14A. As is well known, the DMD comprises a plurality of micromirrors corresponding to a plurality of pixels. As an example, by changing an angle of each micromirror, a reflection direction of the light from the light source 14E is changed between on-light that is incident on the projection optical system 14D and off-light that is not incident on the projection optical system 14D. Then, a light quantity for each pixel is adjusted according to the duration of the on-light.

In the projector <NUM>, the light source 14E is disposed on the projector cooling fan <NUM> side with respect to the emission port <NUM>. In other words, the airflow F2 discharged from the projector cooling fan <NUM> is directed to the light source 14E. A main heat source in the projector <NUM> is the light source 14E. In a case where the airflow F2 after being discharged from the projector cooling fan <NUM> hits a portion of the projector <NUM> on the light source 14E side, the heat of the projector <NUM> (for example, heat generated from the light source 14E) is transferred to the airflow F2.

As described above, in the mammography apparatus <NUM> according to the present embodiment, the radiation source cooling fan <NUM> that sucks the air from the outside and discharges the air that has cooled the radiation source <NUM> from the exhaust port <NUM> provided in the rear wall 22B of the radiation source accommodation portion <NUM> is provided in the radiation source accommodation portion <NUM>. In addition, the projector cooling fan <NUM> that sucks a part of the air directed from the radiation source cooling fan <NUM> to the exhaust port <NUM> and blows the sucked air toward the projector <NUM> to cool the projector <NUM> is provided in the radiation source accommodation portion <NUM>. Further, the flow rate of the projector cooling fan <NUM> is set to be smaller than that of the radiation source cooling fan <NUM>. Then, the air that has cooled the projector <NUM> is discharged from the emission port <NUM>. Thus, a cooling efficiency of the projector <NUM> is improved.

For example, as shown in <FIG> as a comparative example, in a case where a cooling fan that sucks air from the outside and discharges the air that has cooled the projector <NUM> from the exhaust port <NUM> in the same manner as the radiation source cooling fan <NUM> is used as the projector cooling fan <NUM>, there is the following problem. That is, in a case where the flow rate of the projector cooling fan <NUM> is smaller than the flow rate of the radiation source cooling fan <NUM>, the flow of the air directed from the projector cooling fan <NUM> to the exhaust port <NUM> (that is, the airflow F3) is lost to momentum of the air directed from the radiation source cooling fan <NUM> to the exhaust port <NUM>. As a result, the airflow F3 that cools the projector <NUM> does not flow smoothly, which causes a problem in that the cooling efficiency of the projector <NUM> is decreased.

In the present configuration, the projector cooling fan <NUM> sucks a part of the air directed from the radiation source cooling fan <NUM> toward the exhaust port <NUM> and blows the sucked air toward the projector <NUM>. Then, the air that has cooled the projector <NUM> is discharged from the emission port <NUM> which is different from the exhaust port <NUM>. Therefore, since the projector cooling fan <NUM> does not allow the air to flow toward the same exhaust port <NUM> as that of the radiation source cooling fan <NUM>, even in a case where the flow rate of the projector cooling fan <NUM> is smaller than the flow rate of the radiation source cooling fan <NUM>, the air that cools the projector <NUM> can flow smoothly. Thus, a cooling efficiency of the projector <NUM> is improved.

Further, for example, in the present configuration, the airflow F1 discharged from the radiation source cooling fan <NUM> is discharged from the exhaust port <NUM> as well as a part thereof is discharged from the emission port <NUM> as the airflow F2. For this reason, as compared to the comparative example shown in <FIG>, exhausting by the radiation source cooling fan <NUM> is also efficiently performed, so that a cooling efficiency of the radiation source <NUM> is also improved.

In the comparative example shown in <FIG>, for example, it is also conceivable to exhaust the air from the exhaust port <NUM> by making the flow rate of the projector cooling fan <NUM> larger than that of the radiation source cooling fan <NUM>. However, in this case, a power consumption in the projector cooling fan <NUM> increases, and a noise caused by the air blowing becomes a problem. According to the present configuration, an effect of improving the cooling efficiency of the projector <NUM> can be expected while solving the problem of increasing the size of the projector cooling fan <NUM>.

In addition, in the mammography apparatus <NUM> according to the present embodiment, the radiation source accommodation portion <NUM> is provided with the upper flow path <NUM> and the lower flow path <NUM>. The radiation source cooling fan <NUM> is disposed in the upper flow path <NUM>. The projector cooling fan <NUM> and the projector <NUM> are disposed in the lower flow path <NUM>, and the lower flow path <NUM> is a flow path directed from the branch portion <NUM> to the emission port <NUM>. In a region other than the branch portion <NUM>, the partition plate <NUM> is provided between the upper flow path <NUM> and the lower flow path <NUM>. Since the inflow of air from the upper flow path <NUM> to the lower flow path <NUM> from portions other than the branch portion <NUM> is suppressed, turbulence in the flow of the air that cools the projector <NUM> can be suppressed. Thus, a cooling efficiency of the projector <NUM> is improved.

In addition, in the mammography apparatus <NUM> according to the present embodiment, in a case where the distance L1 is from the rear end surface 25C to the exhaust port <NUM>, the distance L2 is from the rear end surface 25C to the branch portion <NUM>, and the distance L3 is from the branch portion <NUM> to the projector cooling fan <NUM>, the sum of the distance L2 and the distance L3 is longer than the distance L1. Accordingly, as compared to a case where the sum of the distance L2 and the distance L3 is shorter than the distance L1, a cooling period of the airflow F2 that is sucked by the projector cooling fan <NUM> and blown to the projector <NUM> becomes longer. Therefore, a temperature of the airflow F2 is sufficiently lowered, and the cooling efficiency of the projector <NUM> by the projector cooling fan <NUM> is improved.

Further, in the mammography apparatus <NUM> according to the present embodiment, the light source 14E of the projector <NUM> is disposed on the projector cooling fan <NUM> side with respect to the exhaust port <NUM>. In the projector <NUM>, the light source 14E is a main heat source. The light source 14E of the projector <NUM> is disposed on the projector cooling fan <NUM> side with respect to the emission port <NUM>. In other words, the projector cooling fan <NUM> blows the air toward the light source 14E of the projector <NUM>. As a result, a flow rate of the air blown to the light source 14E of the projector <NUM> is larger than that of a case where the light source 14E of the projector <NUM> is disposed on the emission port <NUM> side with respect to the projector <NUM>, so that the cooling efficiency of the projector <NUM> is improved.

For example, in the comparative example shown in <FIG>, the projector cooling fan <NUM> sucks the air from the emission port <NUM> and exhausts the air toward the exhaust port <NUM>. Further, the projector <NUM> is disposed between the emission port <NUM> and the exhaust port <NUM> in the lower flow path <NUM>. Therefore, the projector cooling fan <NUM> sucks the air from the projector <NUM> side and discharges the air toward the exhaust port <NUM>. That is, in the comparative example shown in <FIG>, the projector cooling fan <NUM> does not blow the air toward a heat source of the projector <NUM>. In this case, the cooling efficiency is decreased as compared to a case where the projector <NUM> is disposed on an exhaust side of the projector cooling fan <NUM> and is cooled. In the present configuration, the projector cooling fan <NUM> blows the air toward the heat source of the projector <NUM>, so that the projector <NUM> can be cooled more efficiently.

Further, in the present configuration, as described above, since the projector <NUM> is cooled by using the air that has cooled the radiation source <NUM>, it is required to improve the cooling efficiency in the cooling of the projector <NUM>. Therefore, in the present configuration, by disposing the light source 14E of the projector <NUM> on the projector cooling fan <NUM> side with respect to the exhaust port <NUM>, the flow rate of the air blown to the light source 14E of the projector <NUM> increases, and the cooling efficiency of the projector <NUM> is improved.

Further, in the mammography apparatus <NUM> according to the present embodiment, the emission port <NUM> through which the projection light L is emitted from the projector <NUM> also serves as an opening for exhausting the air that has cooled the projector <NUM>. As a result, the air flowing from the emission port <NUM> toward the projector <NUM> is suppressed, so that adhesion of dust or the like to the projection optical system 14D of the projector <NUM> is suppressed.

Further, in the mammography apparatus <NUM> according to the present embodiment, the projector <NUM> is disposed on the radiation source <NUM> side with respect to the radiation source cooling fan <NUM> and the projector cooling fan <NUM>, and in a case where the upper flow path <NUM> and the lower flow path <NUM> are viewed as a whole, the upper flow path <NUM> and the lower flow path <NUM> form a V-shape with the branch portion <NUM> as an apex. Accordingly, since two flow paths of the upper flow path <NUM> and the lower flow path <NUM> can be partitioned by one partition plate <NUM>, it is easy to simplify the configuration as compared to a shape having a plurality of folded portions. In addition, by forming the V-shape, an effect that a thickness of the radiation source accommodation portion <NUM> in the height direction can be suppressed can also be expected as compared to a case of, for example, an L-shape.

The above embodiment has been described with an example of a form in which the air supply port <NUM> is provided on the front side of the top wall 22A of the radiation source accommodation portion <NUM>, but the technology of the present disclosure is not limited thereto. For example, the air supply port <NUM> may be provided on a front wall of the radiation source accommodation portion <NUM>. In addition, the above embodiment has been described with an example of a form in which the exhaust port <NUM> is provided on the rear wall 22B of the radiation source accommodation portion <NUM>, but the technology of the present disclosure is not limited thereto. For example, the exhaust port <NUM> may be provided on the rear side of the top wall 22A of the radiation source accommodation portion <NUM>.

The above embodiment has been described with an example of a form in which the airflow F2 is discharged from the emission port <NUM>, but the technology of the present disclosure is not limited thereto. For example, the airflow F2 may be discharged from an opening provided on a lower surface of the radiation source accommodation portion <NUM> separately from the emission port <NUM>.

In addition, the above embodiment has been described with an example of a form in which the upper flow path <NUM> and the lower flow path <NUM> are formed by the partition plate <NUM>, but the technology of the present disclosure is not limited thereto. For example, the upper flow path <NUM> and the lower flow path <NUM> may be formed by a tubular member provided in the radiation source accommodation portion <NUM>.

Claim 1:
A mammography apparatus comprising:
an arm (<NUM>) that accommodates a radiation source (<NUM>) emitting radiation toward a breast and is supported by a stand (<NUM>);
a first cooling fan (<NUM>) that is disposed on a stand side with respect to the radiation source in the arm, sucks air from an outside of the arm, and discharges air that has cooled the radiation source from a first exhaust port (<NUM>) provided on the stand side with respect to the radiation source;
characterized in that the mammography apparatus comprises
a projector (<NUM>) that is disposed in the arm and projects information;
a second cooling fan (<NUM>) that is disposed between the projector and the first exhaust port in the arm, sucks a part of air directed from the first cooling fan to the first exhaust port, blows the sucked air toward the projector to cool the projector, and has a flow rate smaller than that of the first cooling fan; and
a second exhaust port (<NUM>) that is provided separately from the first exhaust port and through which air that has cooled the projector is discharged.