1. An optical tomographic image acquisition apparatus, comprising:
a light source unit which outputs light;
an interference unit which branches the light output from the light source unit in two to obtain first branch light and second branch light, irradiates a reflector with the first branch light, receives reflected light from the reflector resulting from the irradiation, irradiates an object with the second branch light, receives diffusely-reflected light from the object resulting from the irradiation, and causes the reflected light from the reflector and the diffusely-reflected light from the object to interfere with each other to output interference light;
a scanning unit which scans a radiation position of the second branch light for the object;
a detection unit which detects the interference light output from the interference unit; and
an analysis unit which analyzes a result of the detection by the detection unit to obtain an optical tomographic image of the object,
wherein the detection unit includes
a spectroscopic unit which divides the interference light output from the interference unit and outputs light of each wavelength in a different direction according to the wavelength on a predetermined plane;
a deflection unit which deflects the light of each wavelength output from the spectroscopic unit in a deflection angle direction with respect to the predetermined plane;
a light focusing unit which focuses the light of each wavelength deflected by the deflection unit; and
a light receiving unit which detects power of light arriving at each position on a light receiving surface on which the light is focused by the focusing unit, wherein
the analysis unit obtains the optical tomographic image of the object based on a correspondence relationship between the radiation position by the scanning unit and a deflection angle by the deflection unit and on optical power distribution detected by the light receiving unit.
2. The optical tomographic image acquisition apparatus according to claim 1, wherein the light source unit outputs light in a band including a wavelength range from 1200 nm to 1400 nm or a wavelength range from 1500 nm to 1800 nm.
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 making a positive temperature coefficient device, comprising:
(a) first forming a crosslinkable preform of a positive temperature coefficient polymer composition containing a polymer system and a conductive filler;
(b) then attaching a pair of electrodes to the crosslinkable preform;
(c) next soldering and hot pressing a pair of conductive leads to the electrodes using a lead-free solder paste having a melting point greater than 210\xb0 C. in a hot pressing machine;
(d) next crosslinking the crosslinkable preform after step (c); and then
(e) thermally treating the crosslinked preform after step (d) by iteratively repeating the process of heating the crosslinked preform to the first working temperature and then cooling the crosslinked preform to the second working temperature for a plurality of times, wherein soldering and hot pressing the conductive leads to the electrodes is conducted by applying a pressure to the conductive leads that ranges from 10 psi to 50 psi.
2. The method of claim 1, wherein the soldering in step (c) is conducted at a working temperature greater than the melting point of the lead-free solder paste and not greater than 260\xb0 C.
3. The method of claim 2, wherein the working temperature of the soldering in step (c) ranges from 240\xb0 C. to 260\xb0 C.
4. The method of claim 3, wherein the polymer system contains a crystalline polyolefin selected from the group consisting of non-grafted high density polyethylene, non-grafted low density polyethylene, non-grafted ultra-low density polyethylene, non-grafted middle density polyethylene, non-grafted polypropylene, and combinations thereof, and a copolymer of an olefin monomer and an anhydride monomer.
5. The method of claim 4, wherein the conductive filler is selected from the group consisting of carbon black, metal powder, and a combination thereof.
6. The method of claim 4, wherein the crosslinkable preform is formed by compounding and extruding the positive temperature coefficient polymer composition, the electrodes being attached respectively to two opposite surfaces of the crosslinkable preform through laminating techniques so as to form a laminate in step (b).
7. The method of claim 4, further comprising thermally treating the crosslinkable preform before step (d) by iteratively repeating a process of heating the crosslinkable preform to a first working temperature ranging from 50\xb0 C. to 130\xb0 C. and then cooling the crosslinkable preform to a second working temperature ranging from \u221280\xb0 C. to 0\xb0 C. for a plurality of times.
8. The method of claim 1, wherein the crosslinking operation in step (d) is conducted by irradiating the crosslinkable preform to a dosage of at least 10 kGy using Cobalt-60 gamma-ray irradiation.