BACKGROUND

During the development stage of a printer, it was found that the temperature rise in the light source area was much higher than expected. Since the countermeasures that are available would result in a cost increase, it was decided to apply robust design to reduce the temperature. Normally, trying to lower the temperature requires temperature measurement. Such an approach is not recommended because of two reasons. First, the environmental temperature must be controlled during experimentation. Second, the selection of material must consider all three aspects of heat transfer, i.e., conduction, radiation and convection. Hence, this process is quite time consuming.

To reduce the development time, it was decided to consider the functionality of an airflow (air speed) generation by the cooling fan.

PROCESS

Instead of following the common design-build-test method, the technically more efficient robust design methodology was used and the functionality of the engineering system was studied. Eight control factors were tested by 18 design configurations under two noise levels, with and without obstacle. Motor voltage into the fan was considered the input signal and air speed was measured as the output response.

BENEFITS

• The developmental time was reduced significantly with the help of the robust design approach. It took only four hours to complete the study including the fabrication of the components from cardboard used to build the test pieces.

• A 5.83-dB gain in the S/N ratio was achieved.

• An 11.1-dB improvement in air speed generation was achieved. This is equivalent...