Telecommunication systems have had substantial increase in their usefulness and utility in association with automotive vehicles. Many people are engaged in occupations requiring that they travel, often on a frequent basis, such as in the construction trades or in sales and service businesses. These people may spend a substantial part of their working day in transit between their primary business location and remote work locations or construction sites or the business locations of others and desire to make the travel time also productive. This productivity is not limited merely to the individual who is traveling in the vehicle, and such individuals are usually traveling alone; but, it is also intended to effect increased productivity by associates and support personnel, such as those persons located at a fixed home office location, who are also engaged in the work of the individual who is in a mobile work situation.
One such telecommunication system which has provided impetus for this type of communicating is the cellular telephone. The cellular telephone system, particularly where it is installed in generally large geographical areas, enables the individual who is traveling to keep in contact with a home office and to also communicate with persons with which they are doing business or are engaged in performance of other work projects. Such telecommunications, however, have limitations in that they are essentially confined to verbal transmissions. Persons operating a motor vehicle have, of course, a prime responsibility and requirement to operate the vehicle while it is in transit from one location to another. This primary requirement thus limits the capability of the individual to perform other work functions since only one hand is available to perform those other work functions and an individual can only give limited visual attention to those functions.
Almost all business operations where mobile communications are highly desirable and particularly profitable require data transmissions in addition to voice communications. Such data transmissions are of particular importance in those business systems where computers provide a data source as well as storage for information that usually is placed in a visual form such as printed copies that are then relied upon in performance of additional work functions such as sales order forms, technical specifications for engineering projects as well as many other types of visual data formats.
Data input terminals of the type usually associated with data processing systems have a manually operated entry keyboard comprising a number of electrical switches having finger keypads to effect their actuation that are selectively operated to input alphabetical or numerical indicia into the communicating system. These keyboards in their most common form are of a configuration and pattern similar to a typewriter keyboard and require utilization of both hands of the operator to effect the input. This, of course, is impossible in a mobile type environment since, as was pointed out, the user frequently is traveling alone and therefore must continue use of one hand in maintaining control of the vehicle operation. Even though a person may be adept at operating a conventional input keyboard which is of a configuration resembling the keyboard format of conventional typewriters, it is generally impossible for such a person to maintain any degree of speed and proficiency while utilizing only one hand for the entire keyboard. The problem that is encountered is that a person only learns to use that one hand for operation of only the keys which essentially comprise about one half of the keyboard, the right half by the right hand and the left half by the left hand. The difficulty arises in large part because certain fingers are used with particular keys and it is not easy to modify the sequence so that a key which is normally operated by the little finger of one hand will be operated by the index finger of the other hand. The reverse orientation of fingers as between the two hands introduces this difficulty. Additionally, there is substantial difficulty in repositioning of one hand from one side of the keyboard to the other side to place the set of fingers in general alignment with the keys.
The necessity of single hand operation of a data input terminal has been recognized. One attempt to solve this particular problem is disclosed in U.S. Pat. No. 3,833,765 issued Sep. 3, 1974 to E. H. Hilborn, et al. That patent discloses an input terminal having a keyboard having a set of 12 key switches which is very similar to the well-known touch-key type telephone set. In the illustrative embodiment of that patent, these several keys are ascribed several functions such as multiple alphabetic indicia and enables data to be input by single hand operation. While the system enables single hand operation, it also requires that the operator learn a specific operating technique to effect the input of the data. This is a disadvantage in a situation where a person will also be utilizing conventional input terminals as it is difficult to transfer immediately from one operating system to another.