Overshadowing the exciting news of the Sony Building and successful foreign investment bids were the diligent efforts of the Chromatron development team.
Completed and announced to the public in September 1964, the Chromatron color TV was displayed at the Sony Building and was the focus of much attention. Nonetheless, mounting production costs and its tendency to malfunction made mass production unfeasible.
Numerous practical problems not addressed in Dr. Lawrence's theory arose when producing an operational model. These included troubles derived from the use of high voltage and difficulties in insulating against it. The scanning stripes, which make up the fluorescent screen, must be so thin as to not be detected by the naked eye. At least 270 to 300 stripes are needed for picture resolution. When compressing the stripes, however, the space between the color switching grid wires must be proportionally narrowed. The precision needed to focus the electron beam through the narrowed grid requires high voltage. This, in turn, requires high performance insulation, which is technically difficult. Naturally, the insulation material must tolerate high voltage. The problems involved in determining what materials to use for insulation and how to affix it were not easily resolved. Since the insulated parts were set inside the cathode-ray tube, there were problems creating and maintaining the proper vacuum level inside the tube. The more tests they ran, the more problems they incurred.
To double the brightness of the picture, the development team devised aluminum film for the back of the fluorescent material. Due to high voltage, however, the thin aluminum film was often drawn toward the color-switching grid. As a result, the display would show dark spots in places where the coating had chipped and glittering patches where it had stuck to the grid. Eventually, as large sections chipped off and stuck to the grid, it would short circuit and the switches would stop functioning. Such electrical defects developed one after another.
To compound matters, etching the phosphor was much more difficult with Chromatron than with the shadow mask process. Compared to the optical printing method of the shadow mask process, which etched the phosphor stripes using the rectilinear propagation characteristics of light, the electron beam printing method used in Chromatron involved etching after the cathode-ray tube was assembled. This was extremely time consuming -- in all, one phosphor stripe alone required from forty minutes to an hour to etch. Thus, even if a printing machine was in full operation 24 hours a day, it could only print 24 stripes a day. In order to meet demand within the eight hour working day, Sony would have to buy dozens of printing machines. In any event, it was not a very productive process.
There were no simple answers, research expenses continued to mount. Yoshida, Miyaoka and Ohgoshi, leaders of the Chromatron team, went through one difficulty after another. At this rate, Sony would never claim Chromatron color TV as its fifth innovative product. In fact, those involved considered it more of a  kuro-matron than the Chromatron, kuro meaning struggle in Japanese,.
 Are you sure that the shadow mask doesn't deserve reconsideration? Ibuka suddenly brought this up at a board meeting. It seemed that the ever confident, resolute Ibuka had nearly lost hope. The Chromatron situation was that serious.
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