Hitachi, Ltd.

Takashi Itoh

Masanori Ogino

Yoshiaki Iwahara

Shuichi Sakamoto

Shoji Kuroda

Makoto Kamiya

Miyuki Ikeda

Tsutomu Imai

Takaji Takenaka

Toshiyuki Kimoto

Mituo Takase

Katsumi Seno

Nobuho Takagi

Satoshi Ohtomo

Toshihiko Koseki

A rear projection type display system with a transmissive screen. A transparent reinforcing plate is coupled to a lenticular sheet of the screen on the light output side by a connective member to broaden the horizontal diverging angle by 60 degrees or more to the right and left sides. The duty factor of a black stripe formed on the lenticular sheet is set to 60% or more so improve the contrast of an image. The diverging angle at each point of a vertically-diffusing lens for diverging light in the vertical direction is modulated in accordance with the height of each point to offer a proper visual angle range in the vertical direction.

Rear projection type display system

A uniformity correction signal generating apparatus includes a horizontal address signal generating unit and a vertical address signal generating unit for generating address signals (X) and (Y, y) having one-to-one correspondence to a position on a display screen of a display unit, respectively. Upper and lower adjacent lattice point data are read out from an E.sup.2 PROM on the basis of the address signals X and Y. Interpolated correction data are obtained on the basis of the upper and lower lattice point data and vertical lower address coordinates y. The apparatus is suitable for an auto-scan type display unit and can correct the uniformity for gradation and focus by using the inexpensive E.sup.2 PROM without need of a large capacity expensive E.sup.2 PROM.

Uniformity correction signal generating apparatus for display image

A through hole is formed by a drill in a defective through hole in a board. An insulating resin is coated on the inner surface of the through hole and a cylindrical conductor is closely fixed with an adhesive to the hole h1 to form a reproduced through hole. Thereafter, as usual, a part lead is inserted into and soldered in the reproduced through hole to thereby recover the connection of the lead with the wiring circuit copper foil impaired by the recovering operation of the defective through hole using an external lead.

Methods of recovering a multi-layer printed circuit board

Disclosed is a vertical deflection circuit in which first and second NPN output transistors are connected in series to make up a single-ended push-pull circuit. A vertical deflection coil and a low-value resistor are connected in series between the output terminal of the push-pull circuit and the earth. The second NPN output transistor is driven by a driving transistor which amplifies the oscillated signal produced from a vertical oscillation stage. The voltage generated at the junction point of the vertical deflection coil and the low-value resistor is fed back to the driving transistor. An emitter resistor is inserted between the emitter of the second NPN output transistor and the earth, while a resistor for differentiating the amount of feedback in the former and latter halves of the vertical scanning period is inserted between the emitter of the second NPN transistor and the junction point.

Vertical deflection circuit

A pump starting method for hydraulic machinery such as a pump turbine and a pump having adjustable guide vanes and an inlet valve, by which hydraulic vibrations due to pump no discharge operation can be prevented by beginning pumping-up with said adjustable guide vanes being opened before a main valve included in a said inlet valve is fully opened in starting the pump.

Pump starting method for hydraulic machinery

Growing community of inventors

Hiratsuka, Japan

Takashi Itoh