Nippondenso Co., Ltd.

Denso Corporation

Masami Kataoka

Nobumasa Higo

Hiroyuki Ban

Junji Hayakawa

Tomohisa Yamamoto

Yoshimasa Hara

Katsuhiro Kumazawa

Toshiki Wada

Shinji Tsuda

Toshiharu Shiratsuchi

Nobuhiko Wakayama

Masashi Yamakawa

Tukasa Miyake

Hiroshi Hashimoto

A display system that includes a liquid crystal element, a backlight, an adjustment unit, a light source control unit, and a liquid crystal control unit. The light source control unit operates the backlight to change a light source luminance level of light. The liquid crystal control unit operates a first plurality of pixels of the liquid crystal element to display normal information with a normal tone level. The liquid crystal control unit operates a second plurality of pixels of the liquid crystal element to display emphasis information with an emphasis tone level. When an adjustment value changes within a predetermined changeable range, the luminance level gradually changes with a change of the adjustment value, the normal tone level gradually changes with the change of the adjustment value, and simultaneously the emphasis tone level is maintained to correspond to brightness equal to or greater than brightness of the normal tone level.

Display system

A pointer of a meter such as a speedometer for use in an automobile is so structured that it is observed as if its illuminated length extends upon turning on a key switch and as if its illuminated length is shortened upon turning off the key switch, thereby giving an ornamental effect to the meter. A pointer cover gradually covering or exposing the illuminated pointer may be provided at a vicinity of a zero-scale position. The pointer may be progressively illuminated by plural light sources disposed behind a scale plate by tuning on the light sources one by one. The light sources such as light-emitting diodes may be embedded in the transparent pointer needle. Plural light sources covered by a bimetal cover may be disposed at a foot portion of the pointer needle, and the bimetal cover may be heated to gradually uncover the light sources thereby to progressively illuminate the pointer needle.

Automotive meter having illuminated pointer

In a control apparatus for a self-heating type cold-cathode discharge tube, a microcomputer determines boosting time based on a detected surrounding temperature of the cold-cathode discharge tube. The boosting time is increases as the detected temperature decreases. A switching circuit, powered from a direct current power supply, performs a switching operation based on a determination output from the microcomputer. An inverter circuit actuates the cold-cathode discharge tube based on the switching operation which is duty-controlled. The duty ratio is determined to be higher when the detected surrounding temperature is within a predetermined low temperature range than outside the predetermined low temperature range.

Self-heating type cold-cathode discharge tube control apparatus

An indicator of a meter is driven by a step motor in which a rotating magnetic field formed by field coils which is a composite of magnetic fields of the coils supplied with a sine-wave-driving current and cosine-wave driving current. The indicator is also returned to a stopper located at a zero position of the meter by the rotating magnetic field. A part of the rotating magnetic field, which is formed from the sine and cosine waves in a range of the phase angle between -340 degree and -(180 degree-.DELTA.a degree) in the zero-return process, is cut after the indicator rests on the stopper so that such part of the rotating magnetic field may not separate the indicator from the stopper.

Indicating instrument and method of operation thereof

Indicating instrument

A driving circuit of a pulse motor for use in a vehicle odometer is provided. The driving circuit includes a pulse source for providing drive pulses, in sequence, to a plurality of phase coils of the pulse motor, and a wave-shaper for shaping leading and trailing edges of each of the drive pulses so as to vary at a given rate in plural steps for noiseless smooth rotation of the pulse motor.

Pulse motor driver

A flow rate transducer has a housing in which a cylindrical fluid chamber and a support portion surrounded by an annular guide groove formed coaxial with the fluid chamber are formed. Rotatably carried by the support portion is a vane wheel having plate pieces arranged circumferentially of the vane wheel at regular intervals and extending in the guide groove. A light emitting element and a light receiving element are disposed to face a locus defined by the rotated plate pieces so that, every time the plate pieces pass by the light receiving element, the light receiving element produces an electrical signal to measure the flow rate of a fluid in the fluid chamber. The support portion has vane wheel speed adjusting chambers each having an L-shaped configuration and opening to said guide groove for minimizing the flow rate measurement errors of the flow rate transducer both in the high and low rate regions.

Flow rate transducer

In a flow rate transducer of the type arranged to detect the rotational speed of a blade wheel by transmitting a light beam from one side thereof to the other, a printed circuit board for carrying thereon a light-emitting element and a light-receiving element is provided. The light-emitting element and the light-receiving element are received in recessed portions of a casing made of a transparent material, where all parts including the printed circuit board contained in the casing are fixedly supported by a synthetic resin filling. The optical axes of the light-emitting element and the light-receiving element can be readily adjusted to align before assembled in the casing. The size and shape of the recessed portions may be arranged to correspond to the size and shape of the corresponding light-emitting element and the light-receiving element so that optical axes alignment can be automatically performed when fitted therein.

Growing community of inventors

Anjo, Japan

Masami Kataoka