X-RAY DETECTOR

Abstract: An X-ray detector is provided with a plate-shaped image pick-up device (10) which includes a sensor (5) and has at least one rounded corner. The sensor is provided with signal lines (7) which extend from at least one side (6) of the sensor. The signal lines extending from the side of the sensor are connected to a carrier plate (4, 11) provided with the rounded corner, near the rounded corner the signal lines (7) enclose an acute angle relative to the side.

Description: X-ray detector. The invention relates to an X-ray detector which includes a plate-shaped image pick-up device which is provided with a sensor and has at least one rounded comer, the sensor being provided with at least one signal line which extends from at least one side of the sensor. A signal line is to be understood to mean herein an electrically conductive signal line or signal wire. The sensor of the image pick-up device in an X-ray detector of this kind which is known from EP-B 1-0.714.632, has an octagonal shape so that it can be positioned in a comparatively small housing having rounded comers. The X-ray detector described in EP-B1- 0.714.632 is used to form X-ray images of the teeth in the mouth of a patient. The rounded comers serve to prevent damaging of the oral cavity. The sensor disclosed in EP-B 1-0.714.632 includes, near its center, a read-out register whereto various segments of the sensor are connected. Connection lines for connecting the sensor to, for example an image processing device extend from a side of the sensor. It is a drawback of the known sensor that the part occupied by the read-out register cannot act as a sensor. As a result, the sensor can produce only an interrupted image. It is an object of the invention to provide an X-ray detector in which the sensor can produce an uninterrupted image, it nevertheless being possible for the image pick-up device to have rounded comers so that it can still be accommodated in a comparatively small housing. This object is achieved in the X-ray detector according to the invention in that the signal lines extending from at least the side of the sensor are connected to a carrier plate provided with the rounded comer, the signal lines enclosing an acute angle relative to the side near the rounded co er. These signal lines are employed to read-out signals from the sensor and/or to apply control signals to the sensor. In the sensor according to the invention, all necessary signal lines are situated along one or more sides of the sensor so that an image can be formed by means of the entire surface of the sensor. Because, moreover, near the rounded comer of the carrier plate the signal lines enclose an acute angle relative to the side of the sensor, all required signal lines can be arranged on the carrier plate provided with the rounded comers. A rounded comer of the carrier plate is to be understood to mean herein a comer of given radius, with chamfered edge portions, and any other shape whereby a right- angled comer of a carrier plate is avoided. Because the carrier plate is provided with rounded comers, it can be accommodated in a comparatively small housing. A comparatively small housing is desirable because the manoeuvrability and positionability of the entire X-ray detector is thus enhanced; this is of importance notably for cardiological and vascular applications. Embodiments of the X-ray detector according to the invention are characterized in that near the rounded comer each of at least two lines encloses an acute angle relative to the side, the acute angles being equally large or smaller as the distance from the rounded comer is greater. Depending on the desired further course of the signal lines, the angles may be either equal or different. A further embodiment of the X-ray detector according to the invention is characterized in that beyond a predetermined distance from the rounded comer the signal lines, extending from the sensor at an acute angle relative to the side, further extend transversely of the side. This enables connection of the signal lines at a side which is remote from the sensor to a coupling piece which extends parallel to the side of the sensor, for example a flexible foil provided with lines. The invention will be described in detail hereinafter with reference to the drawing; therein Fig. 1 is a plan view of a known X-ray detector with a rectangular carrier plate, Fig. 2 shows a detail of the X-ray detector shown in Fig. 1, Fig. 3 is a plan view of an X-ray detector according to the invention, and Fig. 4 shows a detail of the X-ray detector shown in Fig. 3. Corresponding components in the Figures are denoted by corresponding reference numerals. Figs. 1 and 2 show a known X-ray detector 1 which includes a square image pick-up device 2 which may be accommodated in a housing 3 denoted by a dashed line. The image pick-up device 2 includes a square glass carrier plate 4 which supports a square sensor 5 which is made of amorphous silicon. Along sides 6, the sensor 5 is provided with signal lines 7 which extend transversely of the associated side 6. At a side which is remote from the sensor 5 the signal lines 7 can be coupled to, for example a coupling piece (not shown) which may include a flexible coil provided with lines. In order to accommodate the signal lines 7 on the carrier plate 4, the sensor 5 is situated at a distance B from the sides 8 of the carrier plate 4. If the carrier plate 4 is to be accommodated in a circular housing 3, the diameter of the circular housing 3 is determined by the diagonal of the sensor plus 2V2B. The distance B is of the order of magnitude of from 20 to 30 mm, so that a saving of from 55 mm to 85 mm in respect of the diameter of the circular housing can be realized. Figs. 3 and 4 show an X-ray detector 9 according to the invention which is provided with an image pick-up device 10 which includes a glass carrier plate 11 and a sensor 5 which is arranged thereon and is made of an amorphous silicon. The sensor 5 has the same dimensions as the sensor 5 of the X-ray detector 1 shown in Fig. 1. Near each comer the carrier plate 11 has three consecutive edge portions 12 which enclose an angle of 22.5° relative to the adjacent side 8 and/or the adjacent edge portion 12. Near the comers 13 of the sensor 5 the signal lines 7 are provided on the carrier plate 11 in such a manner that they enclose an acute angle relative to the associated side 6 of the sensor 5. At a distance from the co er 13 of the sensor 5 the signal lines 7 have portions which extend transversely of the associated side 6. As a result, near the side 8 of the carrier plate 11 the signal lines 7 can be connected to a coupling piece in a manner similar to that described with reference to Fig. 1. In the image pick-up device 10 shown in Fig. 4 the signal line 7 which is situated nearest to the comer 13 of the sensor 5 encloses an angle relative to the side 6 which is larger than the angle β enclosed relative to the side 6 by a signal line 7 situated at a distance from the comer 13. However, all signal lines 7 may alternatively enclose the same angle relative to the side 6. Preferably, the signal lines 7 are provided on the carrier plate 11 in such a manner that the distance between the portions 14 of the signal lines 7 is the same everywhere. If the image pick-up device 10 is to be accommodated in a circular housing 15, as a result of the rounded co ers of the carrier plate 11 the diameter of the housing 15 will be determined exclusively by the diagonal of the sensor 5. Evidently, it is alternatively possible to provide the carrier plate 11 with more edge portions 12 or with a circular edge portion. Evidently, it is also possible to conduct the signal lines in smooth curves from the sensor to an edge of the carrier plate which is situated at a distance from the sensor.

Claims: CLAIMS: 1. An X-ray detector which includes a plate-shaped image pick-up device which is provided with a sensor and has at least one rounded comer, the sensor being provided with at least one signal line which extends from at least one side of the sensor, characterized in that the signal lines extending from the side of the sensor are connected to a carrier plate provided with the rounded comer, the signal lines enclosing an acute angle relative to the side near the rounded comer. 2. An X-ray detector as claimed in Claim 1, characterized in that each of at least two lines near the rounded comer encloses an acute angle relative to the side, the acute angles being equal. 3. An X-ray detector as claimed in Claim 1, characterized in that near the rounded comer each of at least two lines encloses an acute angle relative to the side, the acute angle being smaller as the distance from the rounded comer is greater. 4. An X-ray detector as claimed in Claim 1, 2 or 3, characterized in that beyond a predetermined distance from the rounded co er the signal lines, extending from the sensor at an acute angle relative to the side, further extend transversely of the side. 5. An X-ray detector as claimed in one of the preceding Claims, characterized in that the rounded co er of the carrier plate comprises a number of consecutive edge portions, angles enclosed by the adjacently situated edge portions being equal. 6. An X-ray detector as claimed in one of the preceding Claims, characterized in that the signal lines are provided on the carrier plate by vapor deposition. 7. An X-ray detector as claimed in one of the preceding Claims, characterized in that the carrier plate is a glass plate. 8. An X-ray detector as claimed in one of the preceding Claims, characterized in that the sensor is made of amorphous silicon. 9. An X-ray detector as claimed in one of the preceding Claims, characterized in that the plate-shaped image pick-up device is accommodated in a round housing.

Inventors: DECKERS JACOBUS A J M, VAN VLIET MAARTEN, DECKERS, JACOBUS, A., J., M., VAN VLIET, MAARTEN
Applicants: KONINKL PHILIPS ELECTRONICS NV, KONINKLIJKE PHILIPS ELECTRONICS N.V.
Application year: 1999
Main classification: A61B
IPC codes: A61B6, G01T1, H01L25, H01L27, H01L31