Minolta Company, Ltd.

Minolta Camera Kabushiki Kaisha

Masaaki Miyano

Masayuki Ueyama

Toyotoshi Kawasaki

Minoru Kuwana

Masayuki Miyazawa

Shinichi Suzuki

Yoshihiro Tasaka

Tougo Teramoto

Kyoko Hashimoto

Hiroyuki Ogura

A pulse detection mechanism for detecting the rotation amount of a rotary member and its rotational direction with a high degree of accuracy by reducing the degree of fluctuation in the position of contact between pins and a pulse surface. A rotation shaft to which a pulse plate has been fixed is supported by a shaft insertion hole of a rotation shaft holding member and that of a pin receiving member. Pins are inserted through pin holes formed through the pin receiving member so that one end of each pin contacts the pulse surface and the other end thereof is urged by a leaf spring of a leaf spring member. The pulse surface and the pins are placed in position by the shaft insertion hole of the rotation shaft holding member and that of the pin receiving member so that the pulse detection mechanism so as to prevent a position fluctuation from being reduced greatly.

Rotary pulse detection mechanism

A lens holding frame holding a lens in a lens barrel is arranged, and a contact member extending therebelow is in friction coupling with a driving axis. By applying driving pulses having such a waveform that includes a moderate rising portion followed by an abrupt falling portion to a piezoelectric element, the holding frame is moved along the direction of the optical axis. An index provided at the holding frame is exposed through a slit of lens barrel, and from the position of the lens on the holding frame, information with respect to the distance to the object is displayed. Detection of the position of the holding frame is performed by a position sensor of ferromagnetic thin film magneto-resistive element type (MR sensor) so as to obtain positional information of the lens on the holding frame based on the detection signal, and the obtained information may be displayed on a liquid crystal or other display portion provided on the lens unit or on a camera body.

Apparatus for detecting and displaying position of a lens on an optical

A sliding coupling mounted between a pair of separately rotational members, including a pair of coiled springs, which realizes no rotational delay at time of reversing a rotational direction of one of the rotational members. Each coiled spring has a projecting part extending radially outwardly from one end thereof. The pair of coiled springs are fictionally mounted on an outer surface of one of the rotational members with the circular parts and the projecting parts of the coiled springs being overlapped with each other so that the winding directions of the coiled springs are opposite to each other. The other rotational member has an engaging groove with which the projecting parts of the coiled springs are engaged without a space between each projecting part and a surface forming the engaging groove of the rotational member in each rotational direction. When the rotational direction of the one rotational member is reversed, the rotational direction of the other rotational member is also reversed with no rotational delay.

Drive transmission mechanism

Lens moving apparatus

A zoom lens barrel based on the vari-focal optical system includes a zoom cam ring which is supported only rotatably about the optical axis and a focus cam ring which is supported movably only in the axial direction both fitted on a fixed tube inside a lens barrel. For the alteration of the lens focal length, the zoom cam ring is turned to carry out zooming, and for the focusing of an object, the focus cam ring is moved in the axial direction to carry out focusing, thereby preventing the interference between zooming and focusing caused by the movement of the lens sets. A drive mechanism based on a piezo-electric element is used to move the focus cam ring in the axial direction, thereby simplifying the structure and reducing the weight.

Zoom lens barrel based on the vari-focal optical system

A structure for preventing an image being shaken when a vibration occurs in an optical system so as to stabilize the object. A compensating lens is incorporated in a third lens group of a lens barrel constituting the optical system. The compensating lens is allowed to move within the third lens group and only in a direction perpendicular to the optical axis. A pulse motor mounted on a fixed barrel drives the compensating lens. The rotation of the pulse motor is converted into the rotation of an interlocking lever. The interlocking lever is a straight bar having an uncircular sectional configuration. A driving lever having approximately the same configuration as the sectional configuration of the interlocking lever is slidably inserted thereinto. The driving lever rotates together with the interlocking lever. One end of the driving lever penetrates through the frame of the third lens group, thus contacting the head portion of a pin which presses the compensating lens. When the driving lever rotates, the compensating lens is pressed through the pin. At a position opposed to the pin, a plate urged by a leaf spring supports the compensating lens. A mechanism for driving the compensating lens is provided in x-direction and y-direction with respect to the compensating lens. When the driving lever rotates in the opposite direction, the compensating lens is moved to the initial position by the elastic force of the leaf spring.

Structure for stabilizing image in optical system

A catadioptric lens system capable of an automatic focusing operation without the necessity of increasing the outer diameter of a lens barrel is provided. The catadioptric lens system comprises a focusing optical unit, a focusing optical unit holder capable of movement in a direction of an optical axis of the lens band for holding the focusing optical unit, and a driving means disposed between a mount and a reflecting mirror which is disposed to reflect light coming from an object toward an object side and connected directly or indirectly to the focusing optical unit holder for transmitting a driving force to the focusing optical unit holder at a reduced speed so as to move the focusing optical unit holder in the direction of the optical axis to effect focusing.

Growing community of inventors

Sakai, Japan

Masaaki Miyano