MAMMOGRAPHIC APPARATUS

Abstract

A mammographic apparatus for taking an image of a breast by detecting an X-ray radiated from an X-ray tube and transmitted a breast of a subject by means of an X-ray detector. The mammographic apparatus includes a column, a first support frame arranged, for rotation about a rotary axis, on the column and supporting the X-ray tube, a second support frame arranged, for rotation about the rotary axis, on the column and supporting the X-ray detector, and a mechanism for selectively switching over between a first mode that the second support frame is rotated by a rotation force of the first support frame and a second mode that the first support frame is rotated independently of the second support frame.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

FIG. 1 is a view showing a construction of a mammographic apparatus according to a first embodiment of the present invention;

FIG. 2 is a perspective view showing a FIG. 1 spur gear and arcuate gear with magnification;

FIG. 3 is a view showing a FIG. 1 frame, by partly broken away, and an internal arrangement of a column unit;

FIG. 4 is a view showing a construction of a mammographic apparatus according to a second embodiment in a first status of operation;

FIG. 5 is a view showing the construction of the mammographic apparatus according to the second embodiment in a second status of operation;

FIG. 6 is an exploded view showing a structure of an electromagnetic brake of FIGS. 4 and 5;

FIG. 7 is a view showing a concavo-convex formed in the FIG. 6 clutch plates;

FIG. 8 is a view showing the electromagnetic brake in an open state;

FIG. 9 is a view showing the electromagnetic brake in an locked state;

FIGS. 10A, 10B and 10C are views each showing a positional relationship of between an X-ray tube and an X-ray detector, in taking an image according to the basic radiography; and

FIG. 11 is a view showing a positional relationship of between the X-ray tube and the X-ray detector, in taking an image according to tomosynthetic radiography.

Claims

1. A mammographic apparatus for taking an image of a breast by detecting an X-ray radiated from an X-ray tube and transmitted a breast of a subject by means of an X-ray detector, the mammographic apparatus comprising: a column;a first support frame arranged, for rotation about a rotary axis, on the column and supporting the X-ray tube;a second support frame arranged, for rotation about the rotary axis, on the column and supporting the X-ray detector; anda mechanism for selectively switching over between a first mode that the second support frame is rotated by a rotation force of the first support frame and a second mode that the first support frame is rotated independently of the second support frame.

2. A mammographic apparatus according to claim 1, wherein the mechanism further includes a first motor for rotating the second support frame, a first gear in an arcuate form fixed on the second support frame, a second gear rotatably provided in the first support frame and placed in mesh with the first gear, and a second motor for rotating the second gear.

3. A mammographic apparatus according to claim 2, wherein the mechanism has suppressing means that suppresses the second frame from rotating in the second mode.

4. A mammographic apparatus according to claim 3, wherein the suppressing means has a self-locking function and made as a gear unit that delivers a force of the second motor to the second gear.

5. A mammographic apparatus according to claim 1, wherein the mechanism further comprises a motor for rotating the second support frame, and a clutch that delivers a rotation force of the motor to the first support frame in the first mode but does not deliver same to the first support frame in the second mode.

6. A mammographic apparatus according to claim 5, further including suppressing means that suppresses the second support frame from rotating in the second mode.

7. A mammographic apparatus according to claim 6, wherein the suppressing means is an electromagnetic brake.