A photographic cathode ray tube (CRT) recorder in which the displayed information of two cockpit displays are simultaneously recorded via a slave 2-inch CRT is described in this paper. One display is a 5-inch storage tube and the other is a 9-inch CRT Writing speeds on both displays vary greatly and two shades of gray are required. The recording is further complicated by adjacent overlapping lines in the storage tube display in which exposure to film is increased by as much as 100 times. Proper film exposure is achieved by the control of the slave 2-inch CRT beam current to compensate for line overlapping and writing speeds. Because both displays appear simultaneously, resolution and magnification must be weighted to produce the best compromise for information transfer.
In recent years many types of numeric and alpha-numeric displays have become available. These units have been designed primarily as visual displays for instruments with digital read-out, not for the film data annotation function in which our company has been active. As a result, considerable ingenuity is required to adapt these primarily visual devices for recording alpha-numeric data on film.
There exists an ever increasing need for producing information from a machine or putting information into a machine. This information is often in alphanumeric or pictorial form and is created or presented on two-dimensional media such as film. A computer often processes information serially, so a point of light which can at great speed be controlled on a two-dimensional surface in position and intensity, is the desirable characteristic of film recorders and scanners.
Film recording has been an integral part of the operation of broadcast television ever since its conception. The development of the video tape TV storage system was hailed by some as the death knell to film recording. However, the continuing, need for this transfer technique is demonstrated by the interest of broadcast and military users and by the financial success of studios offering this service. It thus becomes clear that the purpose of film recording of TV images is not in the use of that medium for the dissemination of programs. In fact, in retrospect, it appears that video tape not only did not replace film recording but gave it a new lease on life by allowing the process to be used in an "off line" mode.
Advances in nucleation technology have made possible the thy development of thin-film metallic images on a sensitized substrate at high speed. The media are sensitive to ultraviolet light exposure or may be written upon with a scanning elec tron beam. Development occurs at reduced pressure by the selective condensation of metal atoms from a vapor. This technique for image formation allows development to occur in about one second. Permanent, black-on-white images are produced on the opaque media which are well suited for use in high brightness, reflection displays, or opaque pro lectors. Alternatively, cathodoluminescent readout may be employed to produce a video signal directly from the image. The resolution of the medium exceeds 500 line pairs/mm on a flexible substrate and the granularity is very low.
There are several methods of recording onto microfilm from a computer. My remarks here will be primarily concerned with CRT graphic recording; however, many of the principles are directly related to any type of microfilm recording I wish to discuss the limitations and state of the art as it presently stands in regard to methods employed to obtain precision, high-resolution microfilm recording
The sensitivity of the human eye to slight shifts in color balance, particularly in the blue-green and yellow-orange regions of the spectrum, necessitates careful control over all of the color-influencing parameters of a projection system. In a modern optical projection system, the dichroic coating of an integral reflector tungsten-halogen lamp may be the source of objectionable color imbalance. Despite rigorous manufacturing control, significant variations in spectral energy distribution of radiation reflected and transmitted from the dichroic coatings occur.
COMMENT: Manpower and Scientists
In previous book review sections we have stayed with the tradional idea that technical books are of prime interest to the readers of this section of the journal. In this issue we are departing from this normal situation slightly in reviewing a couple of non-technical books that should be of interest to readers of this journal.