Novel Transfer Assist Blade employing Electro Active Polymers to enable precise and segment-wise actuation
Publication Date: 2005-Dec-05
The IP.com Prior Art Database
This invention proposes to use a properly configured Electroactive Polymer (EAP) to comprize critical parts of a Transfer Assist Blade device. In particular, it teaches use of an "ionmeric-type" EAP adjoined to a modified transfer blade member to create a multi-layer structure wherein the application of a suitable voltage to the EAP layer causes bending deformation in that layer.
Effective transfer of dry toner from photoreceptor to paper within the transfer process requires a minimal level of pressure between the photoreceptor and paper surfaces as well as a suitable electrostatic transfer field. In addition to bias transfer rolls and belts, Transfer Assist Blades (TABs) have emerged as a workable pressure enabling member and when used with a properly designed corotron or scorotron, the pair of devices yields acceptable transfer performance. Ideally, the TAB device is never allowed to contact the photoreceptor otherwise it becomes toner contaminated and the following sheets’ print quality degrades to an unacceptable level. Upon contact, the TAB can also scratch the photoreceptor. Thus, an expensive, complex design and control scheme has emerged for the TAB whereby it is configured in a series of segments, some of which are individually actuated into contact with the main body of the paper to affect transfer while the remaining segments are kept out of contact with the photoreceptor and/or paper edges. Problems with poor transfer with certain rough papers (limited media latitude), with incomplete paper edge transfer (lack of “full bleed”), and with a limited number of TAB sectors are found to be limitations with the present technology.
What is needed is a robust, compact, low energy, low cost, ‘smart’ and easy-to-implement means to improve the overall performance with TAB blades and in so doing solve the known problems.
This invention proposes to use a properly configured Electroactive Polymer (EAP) to comprize critical parts of a Transfer Assist Blade device. In particular, it teaches use of an “ionmeric-type” EAP adjoined to a modified transfer blade member to create a multi-layer structure wherein the application of a suitable voltage to the EAP layer causes bending deformation in that layer. The motion caused by the deformation is translated to the TAB layer resulting in a selectable blade-to-paper load. The load that the EAP can deliver is a funciton of the applied voltage. Proposed also is a large primary region of the multi-layer blade where the EAP is essentially continuous and thereby enables large region actuation of the blade onto the media undergoing transfer. In addition, multiple, secondary regions are proposed where the EAP-coated blade is divided into narrow sectors that can be individually actuated depending upon the size and transfer characteristics of the throughput media. Proposed electrical interconnects on the EAP layer coupled with an integrated, full-process-width, paper sensor can be used for automated selection/actuation of the TAB sectors required to cover the width of the media during transfer. Alternately, the circuitry can be configured along with an interface for the customer to customize ( viz. select and optimize) the transfer pressure and TAB coverag...