1. A method of forging a metallic plate member, comprising steps of:
providing a first die, in which a plurality of first projections are arranged in a first direction with a fixed pitch, each of the first projections being elongated in a second direction perpendicular to the first direction;
providing a second die, in which a plurality of second projections are arranged in the first direction with the fixed pitch, each of the second projections being elongated in the second direction and provided with a concave portion extending in the second direction at a distal end portion thereof;
providing a third die, in which a pair of third projections arranged in the second direction and elongated in the first direction so as to define a groove therebetween, each of the third projections having a flat distal end face;
opposing the first die to a first face of the plate member while opposing the second die to a second face of the plate member;
performing a first forging work by sandwiching the plate member with the first die and the second die in a third direction orthogonal to the first direction and the second direction, so as to generate a plastic flow of a material in the plate member into gaps defined between the first projections while generating a plastic flow of the material into the concave portion of each of the second projection;
opposing the third die to the second face of the plate member, after the first forging work; and
performing a second forging work, by sandwiching the plate member with the first die and the third die in the third direction, such that the flat distal end face of each of the third projections generates a plastic flow of the material into the gaps between the first projections, while a protrusion formed on the plate member by the concave portion is received by the groove,
wherein a plurality of recesses formed by the first projections are partitioned by partition walls formed by the material flown into the gaps between the first projections.
2. A method of manufacturing a liquid ejection head, using the forging method as set forth in claim 1, the manufacturing method comprising steps of:
forming a through hole in each of the recesses so as to communicate each of the recesses with the second face of the plate member;
joining a sealing plate onto the first face of the plate member so as to seal the recesses;
providing a metallic nozzle plate formed with a plurality of nozzles; and
joining the nozzle plate, with an adhesive agent, onto the second face of the plate member such that each of the nozzles is communicated with an associated one of the recesses via the through hole,
wherein the liquid ejection head is configured such that liquid droplets are ejected from the nozzles by pressure fluctuation generated in liquid contained in the recesses.
3. The manufacturing method as set forth in claim 2, wherein a plurality of dents formed by the second projections and remained on the second face of the plate member are used to receive excess adhesive agent when the nozzle plate is joined onto the second face of the plate member.
4. The manufacturing method as set forth in claim 2, wherein a height of one of the flat distal end faces of the third projections which is closer to a portion where the through hole is to be formed is lower than the other one of the flat distal end faces.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for producing an image of a subject positioned in a field of view (FOV) of a medical imaging system, the steps comprising:
a) acquiring with the medical imaging system a plurality of views of the subject positioned in the FOV;
b) producing an image frame data set from selected views acquired in step a);
c) producing a composite image from views acquired in step a) wherein the views combined to produce the composite image includes the views in the image frame data set and additional acquired views;
d) reconstructing a normalized weighting image of the subject, which comprises:
d)i) producing a limited composite data set from the composite image which contains views corresponding to the selected views in the image frame data set;
d)ii) blurring the image frame data set with a filter function;
d)iii) blurring the limited composite data set with a filter function;
d)iv) calculating the normalized weighting image by dividing the blurred image frame data set by the blurred limited composite data set; and
d) producing a highly constrained image of the subject in the FOV by multiplying pixel values in the normalized weighting image by the corresponding pixel values in the composite image.
2. The method as recited in claim 1 in which the views acquired in step a) are projection views acquired at interleaved projection angles, the image data set produced in step b) includes producing the image data set from a selected set of said projection views, and the limited composite data set produced in d)i) is formed by reprojecting the composite image produced in step c) at the projection angles corresponding to the selected set of projection views.
3. The method as recited in claim 1 which includes:
d) producing additional images of the subject by repeating step d) using different ones of the views acquired in step a).
4. The method as recited in claim 1 in which the blurring operations in steps d)ii) and d)iii) are performed by multiplying the data sets by a transformed filter kernel.
5. The method as recited in claim 1 in which the views acquired in step a) are acquired over a period of time during which changes occur in the subject; step b) includes selecting a set of views acquired during a time interval in the performance of step a); and step c) includes selecting a set of views acquired during a window of time that includes said time interval and is longer than said time interval.
6. The method as recited in claim 1 in which the medical imaging system is a magnetic resonance imaging system and each view samples a line in k-space.
7. The method as recited in claim 1 in which step d)iv) is performed by reconstructing a filtered image frame from the filtered image frame data set, reconstructing a filtered limited composite image from the filtered limited composite data set, and then dividing pixel values in the filtered image frame by corresponding pixel values in the filtered limited composite image.
8. The method as recited in claim 1 in which step d)iv) is performed by dividing the blurred image frame data set by the limited composite data set and transforming the result to image space.
9. The method as recited in claim 1 in which the blurring operations in steps d)ii and d)iii) are performed by transforming the data sets to image space and convolving the transformed data sets with a filter kernel.
10. A method for producing an image of a subject, the steps comprising:
a) acquiring with a medical imaging system a composite image of the subject having a relatively high quality;
b) acquiring with a medical imaging system an image frame having a relatively low quality; and;
c) producing a higher quality image frame by:
c)i) producing a normalized weighting image using the image frame and the composite image; and
c)ii) multiplying the normalized weighting image by the composite image.
11. The method as recited in claim 10 in which step c)i) includes blurring the image frame and the composite image and dividing the blurred image frame by the blurred composite image.
12. The method as recited in claim 11 in which the blurring is performed by convolving each image with a filter kernel.
13. A highly constrained reconstruction of an acquired image frame data set the steps comprising:
reconstructing a conventional image frame from the acquired image frame data set;
separating the conventional image frame into a plurality of segments;
reprojecting each image frame segment to form a corresponding plurality of segment projection view data sets; and
reconstructing final image frame segments using corresponding segment projection view data sets in a backprojection process that is highly constrained by a composite image containing a priori information about the subject being imaged.
14. The method as recited in claim 13 in which the final image frame segments are combined to form a final image frame.
15. The method as recited in claim 13 in which a final image segment is selectively displayed.
16. The method as recited in claim 13 in which the composite image is reconstructed using the acquired image frame data set combined with other acquired image data.