Patents by Inventor Takeshi Egawa

Takeshi Egawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4509842
    Abstract: A camera system with an auto-focusing system includes a camera body and an interchangeable zoom lens. The interchangeable objective lens stores various data to be sent to the camera body for improving automatic focus adjustment, such as an information necessary to convert the detected defocus information into a movement of the driving power source to carry out the automatic focus adjustment. The driving power source in the camera body is controlled in response to the data from the interchangeable objective lens and the detected focus information, the driving power being transmitted to the interchangeable objective lens. The camera body is further capable of inhibiting the focus adjustment or focus indication in response to a data from the interchangeable objective lens under an unfavorable condition.
    Type: Grant
    Filed: January 31, 1984
    Date of Patent: April 9, 1985
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Nobuyuki Taniguchi, Norio Ishikawa, Yasuaki Akada, Takeshi Egawa, Kunio Kawamura
  • Patent number: 4492429
    Abstract: As improved mounting device for an optical unit consists of two optical components, one of which is mounted on the other, or else demounted therefrom, by relative rotation of the two with sliding contact of mating seating and mounting faces thereof, wherein in the seating face of the one optical component is formed a positioning recess which is engaged by a positioning member of the other optical component. The positioning member is constantly urged to project beyond the associated mounting face when the other optical component is properly mounted on the one optical component. Along a circular path on the seating face adjacent to the positioning recess is provided an accommodation groove which accommodates the positioning member when the one optical component is turned relative to the other optical component.
    Type: Grant
    Filed: May 21, 1982
    Date of Patent: January 8, 1985
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Yukio Miki, Takeshi Egawa
  • Patent number: 4449807
    Abstract: A driving force transmitting arrangement in an interchangeable optical type optical unit in an optical system including a driving shaft and a driven shaft respectively provided in one part and the other part of the optical instrument which are engageable with or disengageable from each other so that the driving shaft and the driven shaft are connected with or disconnected from each other following the engagement or disengagement between the one part and the other part of the optical instrument. The driving force transmitting arrangement includes a motor for rotating the driving shaft for focusing of the optical system interchangeable optical instrument, and a circuit having a controller of the motor, and a switch to be closed according to connection between the driving shaft and driven shaft.
    Type: Grant
    Filed: April 7, 1982
    Date of Patent: May 22, 1984
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Yukio Miki, Takeshi Egawa
  • Patent number: 4435058
    Abstract: An auto-focus control camera includes an arrangement for measuring distance to a subject to be photographed, a calculator for calculating the degree of out of focus and an actuator for actuating a motor that shifts camera picture taking lens to a proper focus position according to the calculated result. The auto-focus control camera further includes a detector for detecting a time it takes for the arrangement of distance measuring and calculator to complete its operation. If the detected time is within a predetermined time period, the actuator is made operative to complete the photographing operation with auto-focusing, and if the detected time is longer than the predetermined time period, the photographing operation is carried out without auto-focusing.
    Type: Grant
    Filed: February 17, 1982
    Date of Patent: March 6, 1984
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Fumio Yoshida, Yukio Miki, Takeshi Egawa, Akira Yoshizaki
  • Patent number: 4431285
    Abstract: A movable mirror arrangement for use in a single lens reflex camera, including a main mirror and an auxiliary mirror. The arrangement includes a pivotal shaft about which the auxiliary mirror is pivoted towards the main mirror at the time of photographing an object, a main mirror holder having an opening formed larger in size than the auxiliary mirror, and a masking plate for shielding, at the time of photographing the object, a clearance formed adjacent to the pivotal shaft of the auxiliary mirror between the auxiliary mirror and the opening.
    Type: Grant
    Filed: June 21, 1982
    Date of Patent: February 14, 1984
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Hideo Kajita, Takeshi Egawa, Yukio Miki
  • Patent number: 4419000
    Abstract: A single lens reflex camera includes a body member having an intermediate compartment containing the photographic and view finding light paths, the shutter, reflex mirror and mirror viewing components and a pair of opposite side compartments respectively housing the film takeup and rewind mechanisms. A motor is housed in a first of the side compartments and a transmission shaft extends from the mechanism in the second compartment to the first compartment through a space offset from the light paths and a selector mechanism alternatively drive couples the transmission shaft at the first compartment housed film mechanism. The selector mechanism is controlled by an externally accessible knob or is responsive to the direction of rotation of the motor.
    Type: Grant
    Filed: October 19, 1981
    Date of Patent: December 6, 1983
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Fumio Yoshida, Yukio Miki, Takeshi Egawa
  • Patent number: 4413894
    Abstract: An interchangeable lens for a camera is constructed such that as a lens shifting ring for focusing an optical system of the interchangeable lens is shifted to a position for manual focusing, a driven shaft for focusing retracts to be disengaged from a driving shaft inside a camera body with simultaneous connection of a means for transmission of driving force from the lens shifting ring to a lens shifting mechanism. This means for transmitting driving force from the lens shifting ring to the lens shifting mechanism is disconnected as the lens shifting ring is shifted to a position for automatic focusing with resultant engagement of the driven shaft with the driving shaft.A camera is equipped with a detecting member which is shifted to an operating position as the driving shaft for driving the driven shaft of the mounted interchangeable lens is engaged with the driven shaft and a means for opening and closing an electric circuit for focusing according to shifting of the abovementioned detecting member.
    Type: Grant
    Filed: June 25, 1982
    Date of Patent: November 8, 1983
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Yukio Miki, Takeshi Egawa
  • Patent number: 4405221
    Abstract: In a motor drive mechanism for a camera, a film winding mechanism is actuated by a first motor and a second motor is selectively connected to either a control device for automatically performing a preparatory photographic operation prior to the commencement of an exposure or to a film rewinding mechanism.
    Type: Grant
    Filed: October 14, 1981
    Date of Patent: September 20, 1983
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Fumio Yoshida, Yukio Miki, Takeshi Egawa
  • Patent number: 4309078
    Abstract: A pentagonal prism for use in a viewfinder of a single lens reflex camera is made of a glass whose refractive index and Abbe number are not less than 1.6 and 45, respectively. Effective optical path regions on a pair of roof surfaces of the prism are left transparent so that viewfinder light can be totally reflected at both of the roof surfaces. A light absorbing paint is coated in an upper front surface, a pair of said surfaces of the prism as well as at regions other than effective optical path region of the roof surfaces, a bottom light incident surface and a rear light exit surface of the prism. The light absorbing paint prevents the occurrence of ghost images in the view field of the viewfinder. New type glasses suited for the prism are proposed.
    Type: Grant
    Filed: May 7, 1980
    Date of Patent: January 5, 1982
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Kyoichi Hara, Yasuo Yamazaki, Takeshi Egawa
  • Patent number: 4293185
    Abstract: An optical conversion attachment assembly for objective camera lenses is provided to convert a lens into a monocular optical device. A camera exchangeable lens can be detachably mounted on the barrel of an optical attachment having an erecting prism and an ocular system to vary the diopter power. The optical attachment further provides a device for automatically contacting and holding the diaphragm of the camera exchange lens at a maximum aperture opening.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: October 6, 1981
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Yasuo Yamazaki, Takeshi Egawa
  • Patent number: 4278339
    Abstract: A pentagonal prism for use in a viewfinder of a single lens reflex camera makes use of total reflection of viewfinder light flux at effective optical path regions on its pair of roof surfaces. The prism constitutes a module together with a protection cover attachable thereto for protection of the roof surfaces. The cover is provided with a pair of roof walls accomodated to the roof surfaces of the prism and including recessed portions corresponding to the effective optical path regions on the roof surfaces and peripheral portions corresponding to portions on the roof walls out of the effective optical path regions. Upon attachment of the cover to the prism, the peripheral portions contact the portions on the roof surfaces out of the effective optical path regions and an air space which ensures the total reflection is left between the inner surfaces of the recessed portions and the effective optical path regions on the roof surfaces.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: July 14, 1981
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Isamu Uchida, Yasuo Yamazaki, Takeshi Egawa
  • Patent number: 4217044
    Abstract: An indicating device for a camera, which includes a viewfinder and which is selectively settable to either an automatic diaphragm control mode or an automatic shutter speed control mode, enables selective observation of the f-number and the shutter speed scales in accordance with the selection of the exposure control modes. The f-number and shutter speed scales are provided on a common transparent scale plate which is interconnected with an exposure control mode selecting member by a scale shifting mechanism. The scale shifting mechanism shifts the scale plate to a first position wherein only the f-number scale is in the viewfinder optical path upon selection of the automatic diaphragm control mode, and to a second position wherein both the f-number scale and the shutter speed scale are in the viewfinder optical path. A scale shielding member is provided within the viewfinder optical path to shield the f-number scale when the scale plate is in the second position.
    Type: Grant
    Filed: November 16, 1977
    Date of Patent: August 12, 1980
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Keiji Yamazaki, Takeshi Egawa, Yasuo Yamazaki, Hiroshi Ueda
  • Patent number: 4217048
    Abstract: An improved eyepiece for a viewfinder of a single lens reflex camera is provided. This improved eyepiece is capable of adjusting both the diopter and astigmatism correction to the demands of the individual user. The eyepiece includes a negative meniscus lens element convex to the object side and a stationary positive lens element. As the negative lens element is movable along the optical axis it adjusts the diopter of the viewfinder. A pair of relatively rotatable prisms is capable of providing variable astigmatism correction.
    Type: Grant
    Filed: March 13, 1979
    Date of Patent: August 12, 1980
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventor: Takeshi Egawa
  • Patent number: 4206988
    Abstract: A viewfinder for a single lens reflex camera of the T.T.L. light measurement type, wherein light measurement is apt to be affected by external light entering through an eyepiece, includes a diopter adjusting mechanism and an eyepiece shutter. The eyepiece is divided into at least a movable first optical element and a fixed second optical element. The diopter adjusting mechanism is capable of shifting the first optical element for diopter adjustment within a predetermined space which extends along the viewfinder optical axis and is at least partially common to a space that the eyepiece shutter occupies at an advanced position for blocking the viewfinder optical path. Operation of a manually operable member for shifting the eyepiece shutter toward the advanced positon causes the first optical element to be retracted toward the rear away from the predetermined space prior to the shift of the eyepiece shutter into the advanced position.
    Type: Grant
    Filed: April 12, 1979
    Date of Patent: June 10, 1980
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Takayoshi Miyamoto, Takeshi Egawa, Yasuo Yamazaki