HP DeskJet 1200C printer architecture - includes related articles on use of solid modeling CAD system in design, on how reusable packaging and rugged design can minimize environmental impact, and on a new model for product development - HP DeskJet 1200C and HP DeskJet 1200C/PS ink-jet printers - Technical

Hewlett-Packard Journal, Feb, 1994 by Kevin M. Bockman, Anton Tabar, Erol Erturk, Robert R. Giles, William H. Schweibert

LaserJet Compatibility. To be compatible with the HP LaserJet print margins, the design team found it necessary to define the interface between the print cartridge and the media path for good control over the media. At both the top and the bottom of the page, the physical sheet experiences a handoff to or from a set of drive wheels. Tiffs interface is a source for potential print quality errors especially during full area fills or the splitting of large text in the handoff region.

Size. With desktop space at a premium, the product size was under scrutiny all the time. An overall limitation was set on the size and the design team was challenged to operate within it. At every step of the way each design decision had to address the question, "Can it be made smaller or can it be eliminated?" One benefit of small size is the often overlooked aspect of shipping. Since most of the shipping cost comes from the size rather than the weight, the overall exterior dimensions are critical. In addition, the products are shipped on discrete pallets of a predetermined standard size, which has an influence on packaging efficiency.

High-Volume Production. A sharp focus was placed on low-cost manufacturing and product assemblability right from the start. Detailed attention was given to each system to choose the best technology for both functionalitc and cost and to scrutinize the way in which the parts were assembled. A lot of attention was given to ergonomic aspects of the assembly process as the cycle times were reduced and the possibility for repetitive motion injuries increased. In most cases, a solution came from changing the design, designing special dedicated assembly tooling, or using a highly automated assembly line.

Product Architecture

The product architecture establishes the boundaries of the product, provides a path to successful development of the product, and defines the product's fundamental feature set. The major systems defined by the Deskjet 1200C product architecture are the electrical system, the firmware system, and the mechanical system.

The architecture defines the layout of the machine by identifying the subsystem boundaries and component locations and by defining how the various designs integrate. It addresses issues such as user interfaces (how will the paper be loaded?), manufacturing processes for individual parts, manufacturing assembly of the whole product, and servicing of the product by company service representatives.

As a process, the product architecture acts as an organizational structure within which the individual designs are developed. It provides a negotiation mechanism between the various groups defining the product features.

Fast-track development of the Deskjet 1200C primer did not affect the product architecture as much as it did parts development, where rapid prototyping was necessary to squeeze time out of the schedule. Still, there was a continual emphasis placed on reducing design risks and consequently the potential for project delays. This conservative design approach provided substantial time savings throughout the project.