Nec Corporation

Iix Inc.

Keisuke Okada

Takashi Sakamoto

Makoto Hatakenaka

Kiminori Ishido

Ryo Maniwa

Kouichi Hirosawa

Seiji Furui

Takumi Hiroto

Junichi Taneda

An unevenness correction system according to the present invention includes a panel drive circuit provided with a gamma correction circuit that performs gamma correction on an image signal input to an input interface, a gamma correction information acquisition circuit that acquires a gamma correction signal obtained through gamma correction as gamma correction information, an unevenness correction circuit that performs an unevenness correction on the gamma correction signal based on correction data, and an output interface that externally outputs the gamma correction information, and an unevenness correction apparatus provided with a pattern generator that outputs the image signal of a predetermined image to the input interface, and a control unit that generates correction data based on gamma correction information of each individual display panel input to and read by a gamma correction information reading unit from the output interface regarding the output image signal.

Unevenness correction system, unevenness correction apparatus and panel drive circuit

A recording medium stores data supplied from an external device. A memory stores an erase program for executing erasing of the data stored in the recording medium. An erasing unit erases the data stored in the recording medium in accordance with the erase program stored in the memory, in accordance with a start instruction for instructing a start of erasing the data supplied from the external device.

Data storage device and method of erasing data stored in the data storage device

In a method for producing a multilayer printed wiring board, first and second copper foils for surface layer are disposed on both sides of an inner wiring substrate so that each of first and second prepreg sheets provided with through-holes is sandwiched between each of the copper foils for surface layer and each face of the substrate, the through-holes being formed therethrough at desired positions corresponding to positions where the connecting pads on each face of the substrate are formed, and the resulting structure is integrally bonded by applying heat and pressure thereto. During the heat- and pressure-processing step, the through-holes within the prepreg sheets are filled with a resin fused from the prepreg sheets. After selectively removing the copper foil for surface layer within an area which matches each of the connecting pads, the resin is selectively removed by the irradiation of laser beams to form via holes and allow the connecting pads to be exposed. Next, a conductive paste is embedded in the via holes. According to the above-mentioned method, it is possible to suppress occurrence of defective in boring of the via hole for electrically connecting circuit patterns of the surface layer to circuit patterns of the inner layer and also to shorten the production term and reduce the production cost.

Method for producing multilayer printed wiring boards

A multilayered board is formed by applying a photosensitive insulating resin layer on a laminated plate on which via holes and a circuit pattern are formed, followed by the formation of photoviaholes through the photoprinting method, plating and etching. Then, the multilayered board is adhered to another multilayered board prepared in the same manner through a prepreg layer and a conductive paste while applying heat and pressure to give a multilayer printed wiring board. According to this method, electrical connections between the conductive layer of the upper-most layer and the inner conductive layers, between the inner conductive layers, and between the lower-most conductive layer and the inner conductive layers can be achieved through the photoviaholes and the conductive paste. Therefore, it is not necessary to form through-holes for the electrical connection therebetween. The multilayer printed wiring boards can be substantially improved in the number of layers and wiring density thereof.

Disclosed is a process for preparing a multi-layer printed wiring board including the step of forming a through hole and an external layer circuit on a laminated board of double-sided or multi-layer construction. Then the laminated board is coated over the whole front and back surfaces with a paste-like heat-resistant resin, simultaneously filling the through hole with a resin. A copper foil is disposed on the whole front and back surfaces of the laminated board. Next, the arrangement is heated and pressure-molded in a vacuum. The copper foil is then removed to form an intermediate laminated board. Then, multilayer molding of at least two sets of intermediate laminated boards with a prepreg interposed therebetween is preformed via a step of heat and pressure-molding. In using the penetrated through hole as the divided via hole, there is no longer a restriction of the thickness of the respective divided via holes on the same lattice point. Thus, it has become possible to use the via holes in a higher multilayer board, dramatically improving wiring capacity over the prior art divided via holes.

Growing community of inventors

Tokyo, Japan

Keisuke Okada