Abstract: Silicon wafers in the entire volume of which crystal lattice vacancies are the prevalent point defect type, have a rotationally symmetric region whose width is at least 80% of the wafer radius, crystal lattice vacancy agglomerates of at least 30 nm in a density ?6·103 cm?3, crystal lattice vacancy agglomerates of from 10 nm to 30 nm in a density of 1·105 cm?3 to 3·107 cm?3, OSF seeds in a density of 0 to 10 cm?2, and an average bulk BMD density of 5·108 cm?3 to 5·109 cm?3, which varies at most by a factor of 10 radially over the entire silicon wafer, and a BMD-free layer on the front side, wherein the first BMD is found at a depth of at least 5 ?m and on average at a depth of at least 8 ?m.

Abstract: The epitaxial layer defects generated from voids of a silicon substrate wafer containing added hydrogen are suppressed by a method for producing an epitaxial wafer by: growing a silicon crystal by the Czochralski method comprising adding hydrogen and nitrogen to a silicon melt and growing from the silicon melt a silicon crystal having a nitrogen concentration of from 3×1013 cm?3 to 3×1014 cm?3, preparing a silicon substrate by machining the silicon crystal, and forming an epitaxial layer at the surface of the silicon substrate.

Abstract: A silicon wafer having no epitaxially deposited layer or layer produced by joining to the silicon wafer, with a nitrogen concentration of 1·1013-8·1014 atoms/cm3, an oxygen concentration of 5.2·1017-7.5·1017 atoms/cm3, a central thickness BMD density of 3·108-2·1010 cm?3, a cumulative length of linear slippages ?3 cm and a cumulative area of areal slippage regions ?7 cm2, the front surface having <45 nitrogen-induced defects of >0.13 ?m LSE in the DNN channel, a layer at least 5 ?m thick, in which ?1·104 COPs/cm3 with a size of ?0.09 ?m occur, and a BMD-free layer ?5 ?m thick. Such wafers may be produced by heat treating the silicon wafer, resting on a substrate holder, a specific substrate holder used depending on the wafer doping. For each holder, maximum heating rates are selected to avoid formation of slippages.

Abstract: The present invention relates to limiting an x-ray beam used in connection with dental extra oral imaging by a plate mechanism (1) arranged to be operated by a drive mechanism including an actuator (3) arranged to move at least one plate element (2, 3) comprised in the mechanism (1). The plate mechanism (1) includes at least a first and a second plate element (2, 3) which include at least a first slot (12) and a second slot (13), respectively, and said drive mechanism is arranged to directly or indirectly move said first plate element (2) independently of location of said second plate element (3) and said second plate element (3) is arranged to be moved as dependent on the movements of said first plate element (2) only.

Abstract: The invention concerns an integrated dental care apparatus which comprises a patient chair and a dental care unit, which according to the invention are arranged to comprise means for mounting the dental care unit on a floor while the dental care unit and the patient chair are structurally connected by means which support the patient chair, and wherein both the dental care unit and the patient chair are arranged to comprise means for enabling them to be turned in relation to a vertical axis.

Abstract: The invention relates to a skid device (6) for spotlights with skids (7, 8), which extend essentially parallel to the optical axis of the spotlight, and cross members (11, 12), which connect the skids (7, 8) to one another and which serve to hold a bottom section of the spotlight housing (3). The invention provides that at least one skid (7, 8) has a section (73 to 75, 83 to 85) situated at an angle to the center longitudinal axis (M) of the spotlight housing (1, 3).

Abstract: A panoramic X-ray apparatus, comprising at least a support element (2), a patient support (9) arranged to be movable in a vertical direction and an imaging station (4a). The panoramic X-ray apparatus has a support structure (4) arranged to support at least the imaging station (4a), and it has an actuator (15) producing a vertical linear motion for moving at least the imaging station (4a) to different height positions. The panoramic X-ray apparatus comprises a transmission mechanism (28) which affects the velocity/travel distance of the vertical movement of the imaging station (4a) and which is connected at least to the actuator (15) and either to the aforesaid support structure (4) or to the aforesaid support element in such manner that the velocity/travel distance of the vertical movement of the imaging station (4a) is substantially greater than the velocity/travel distance of the motion imparted by the actuator (15) to the transmission mechanism (28).

Abstract: Semiconductor wafers composed of monocrystalline silicon and doped with nitrogen contain an OSF region and a PV region, wherein the OSF region extends from the center radially toward the edge of the wafer as far as the Pv region; the wafer has an OSF density of less than 10 cm?2, a BMD density in the bulk of at least 3.5×108 cm?3, and a radial distribution of the BMD density with a fluctuation range BMDmax/BMDmim of not more than 3. The wafers are produced by controlling initial nitrogen content and maintaining oxygen within a narrow window, followed by a heat treatment.

Abstract: The invention relates to a method and an arrangement for controlling the movements of the functional elements (13-16) of an X-ray apparatus, such as a panoramic X-ray apparatus. In the method, one or more power means (1) provided with a control system (21), a power stage (11) and a rotating power output shaft (2) is/are controlled so as to produce the aforesaid movements of the functional elements. The power output shaft (2) of the power means is caused to rotate by the control system and the power stage so that the power output shaft is in direct contact with the force receiving means (3, 3a) of the functional element.

Abstract: A silicon wafer having no epitaxially deposited layer or layer produced by joining to the silicon wafer, with a nitrogen concentration of 1·1013-8·1014 atoms/cm3, an oxygen concentration of 5.2·1017-7.5·1017 atoms/cm3, a central thickness BMD density of 3·108-2·1010 cm?3, a cumulative length of linear slippages ?3 cm and a cumulative area of areal slippage regions ?7 cm2, the front surface having <45 nitrogen-induced defects of >0.13 ?m LSE in the DNN channel, a layer at least 5 ?m thick, in which ?1·104 COPs/cm3 with a size of ?0.09 ?m occur, and a BMD-free layer ?5 ?m thick. Such wafers may be produced by heat treating the silicon wafer, resting on a substrate holder, a specific substrate holder used depending on the wafer doping. For each holder, maximum heating rates are selected to avoid formation of slippages.

Abstract: The invention relates to a medical imaging means including a movement mechanism (10). The movement mechanism (10) comprises a first mounting part (21) and a second mounting part (22) and at least three link arm members. The link arm assemblies of the mechanism include actuator means and a link arm member or a set of link arm members. The movement mechanism is used for moving a medical imaging device or a part thereof.

Abstract: This invention relates to tomographic imaging and is particularly intended to be applied to medical x-ray photography. An object of the invention is to provide an imaging mode where the imaging means can follow the anatomy of the object to be imaged without having to make compromises between the thickness of the layer to be imaged and the optimal imaging path, i.e., a path which is perpendicular to the object to be imaged. The invention provides a new way of producing tomographic effect in tomographic methods based on the use of a narrow beam, the new way being based on the idea that the rotational direction of the beam is changed in the object to be imaged during an imaging scan.

Abstract: The present invention relates to a cranial radiography apparatus, particularly intended for dental panoramic radiography, said apparatus comprising a first body part to which is connected a second body part (13) having thereto connected a third body part (14) to which is connected a fourth body part (15). To the opposite ends of said fourth body part (15) are connected an x-ray source and an x-ray detector. The body parts are connected to each other by means of pivot shafts aligned essentially parallel to each other. The pivot shafts are rotated by means of active actuators and their rotational movement is programmably controlled by means of a computer, thus permitting the x-ray source and the x-ray detector to be moved over any predetermined orbit. The apparatus further includes means for radiography using a cephalostat.

Abstract: This invention relates to tomographic imaging, and particularly to producing complex motion or spiral tomography images in medical X-ray imaging. According to the invention, a curved path is arranged for the radiation source of the imaging apparatus in the vertical direction with respect to the object to be imaged, and a counter-movement with respect to the curved movement of the radiation source in the vertical is implemented by moving the radiation detector substantially linearly with respect to the radiation source on the opposite side of the object to be imaged. It is also preferable to keep the detector constantly parallel with a cross-sectional plan through the object to be imaged.

Abstract: A method of producing complex motion or spiral tomography images in tomographic imaging, comprising the steps of positioning an object to be imaged in a fixed position, arranging a radiation source on one side of the object to be imaged, arranging a detector on a second diametrically opposed side of the object to be imaged from the radiation source, the detector receiving radiation from the radiation source, while the radiation is being received, rotating the radiation source and the detector substantially around a vertical axis passing through the object to be imaged in a controlled manner whereby a tomographic effect is produced, while the radiation is being received, moving the radiation source in a first vertical direction, while the radiation is being received and simultaneously with the step of moving the radiation source, moving the detector in a second vertical direction opposite from the first vertical direction, and wherein the radiation source and the detector are moved independently from one anoth