In A Camera Patents (Class 352/91C)
  • Patent number: 5483293
    Abstract: In an output control device which controls an amplification factor of an amplifier in response to an input signal and a fade control signal to carry out a fade operation of an output signal, such as a fade-in or a fade-out operation, a level control signal is produced to widely control output levels of the output signal. A plurality of timing signals are produced from either the fade control signal or the level control signal and are selected in response to the level control signal and are selected in response to the level control signal to determine a combination of the timing signals. The amplification factor is controlled by the combination of the timing signals to change the output levels over a wide range by varying the combination of the timing signals from one to another.
    Type: Grant
    Filed: July 11, 1994
    Date of Patent: January 9, 1996
    Assignee: NEC Corporation
    Inventor: Yasuhiko Okuhara
  • Patent number: 4602857
    Abstract: A panoramic motion picture camera for continuously nonintermittently exposing a filmstrip in which a camera body assembly includes a stationary housing portion and a rotatable housing portion, the rotatable housing portion including an upper housing section and a lower housing section rotatable about an axis of rotation. Camera components including a lens means, a film gate, a main film sprocket, a film supply sprocket, and film idler spools providing a film path are enclosed within the upper housing section while a film supply reel and film take-up reel coaxially arranged and in spaced planar zones are contained within the lower housing section of the rotatable portion. Bidirectional film spools translate the filmstrip from the supply reel to the film path provided in the upper housing section and then to the film take-up reel at the lower part of the lower housing section.
    Type: Grant
    Filed: July 30, 1984
    Date of Patent: July 29, 1986
    Assignee: James H. Carmel
    Inventors: Robert L. Woltz, Thomas E. Brentnall
  • Patent number: 4456349
    Abstract: This invention relates to a cinematographic camera and more particularly to a method of controlling operation of the cinematographic camera in accordance with a sequence of instructions programmed to carry out a photographic process. In order to carry out a plurality of operating modes by use of one and the same control circuit, the program is planed to include a plurality of different photographic process program sections along with a selection program for selection of any one of said process program sections.
    Type: Grant
    Filed: January 29, 1980
    Date of Patent: June 26, 1984
    Assignee: Canon Kabushiki Kaisha
    Inventors: Noritsugu Hirata, Hidekazu Okajima, Tomoshi Takigawa, Toshikazu Ichiyanagi, Hiroyuki Takimoto
  • Patent number: 4326782
    Abstract: A sound motion picture camera capable of overlapping exposures by automatically controlling the sequence of a first step beginning with stopping of the take-up spool in a film cassette from further rotation in response to initiation of an overlapping exposure operation and terminating with a predetermined length of film being accumulated in the cassette in the form of a slack loop, a second step of rewinding the length of the looped film without further exposing the film and a third step of transporting the rewound film in the forward direction again while exposing the film again, characterized by the provision of control means for allowing release of a head pad from pressure contact against the magnetic head when the above second step starts.
    Type: Grant
    Filed: September 4, 1979
    Date of Patent: April 27, 1982
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidekazu Okajima
  • Patent number: 4322140
    Abstract: In the disclosed motion picture shutter angle control device, a motor serves exclusively for varying the shutter opening angle formed with a number of shutter blades. A detector detects when a predetermined shutter opening angle is obtained and delivers a signal which is used in a fade operation and the overlap operation to change the maximum opening angle.
    Type: Grant
    Filed: September 7, 1979
    Date of Patent: March 30, 1982
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroyuki Takimoto, Masamichi Toyama
  • Patent number: 4313653
    Abstract: Controller for the lapping, fade out and fade in photography of a cinecamera, in which a diaphragm is slowly stopped down partially, photography is interrupted, and the diaphragm is further rapidly stopped down to its full stroke with the shutter being shut off. The film is rewound a predetermined amount with shutter and diaphragm under that condition. The diaphragm is then rapidly opened with the shutter being shut off to effect the stand-by operation so that the fade-in photography may be started.
    Type: Grant
    Filed: September 12, 1979
    Date of Patent: February 2, 1982
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventor: Kuniharu Takeda
  • Patent number: 4311369
    Abstract: In the disclosed sound motion picture camera, a sound overlap device keeps the sound level constant during a predetermined time after the start of a fade out operation, then gradually lowers the sound level and then gradually raises the sound level during the start of a fade in operation.
    Type: Grant
    Filed: August 31, 1979
    Date of Patent: January 19, 1982
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yutaka Kohtani
  • Patent number: 4202610
    Abstract: A motion-picture camera switchable to long-term exposure, in the presence of insufficient illumination for normal filming, has a photodetector which in the long-term mode controls a timing circuit measuring the length of an exposure period during which the camera shutter is arrested in an unblocking position, that period varying inversely with the detected intensity of incident light. In order to provide a fade-out effect at the end of a scene taken in this manner, the exposure period is progressively shortened--or the diaphragm aperture is progressively reduced--in discrete steps during successive shutter cycles to substantially complete cutoff. For fade-in at the beginning of a scene filmed with long-term exposure, the opposite procedure is followed.
    Type: Grant
    Filed: September 20, 1978
    Date of Patent: May 13, 1980
    Assignees: Karl Vockenhuber, Raimund Hauser
    Inventor: Gerd Kittag
  • Patent number: 4200364
    Abstract: A motion picture camera wherein the diaphragm is adjusted in automatic response to signals from two outputs of a digital comparator which receives a first set of signals during each revolution of the shutter at a frequency varying as a function of changes of shutter speed and of changes of scene brightness. The comparator further receives a set of reference signals from a digital selector circuit during normal operation of the camera or from a binary counter when the camera is set for making exposures with fade-in, fade-out or lap dissolve. The counter forms part of a program circuit.
    Type: Grant
    Filed: July 26, 1978
    Date of Patent: April 29, 1980
    Assignee: AGFA-Gevaert, A.G.
    Inventors: Kurt Borowski, Istvan Cocron, Theodor Huber
  • Patent number: 4153352
    Abstract: Normally, the negative-feedback diaphragm control system of the motion-picture camera works off a through-the-lens photosensitive element. However, when an image fadeover is to be effected, the lower than normal-operation aperture size commanded for the diaphragm results in a decrease in the light incident on the through-the-lens photosensitive element creating problems if the diaphragm control system is to continue to respond to scene-light changes during the lower than normal-operation aperture-size situation. Accordingly, the through-the-lens photosensitive element is switched out of the control system, and a second photosensitive element is switched in. The second photosensitive element does not operate through-the-lens, but instead is positioned behind an auxiliary light attenuator the front of which is exposed to ambient scene light. The auxiliary light attenuator is coupled to the diaphragm and diaphragm-adjusting motor.
    Type: Grant
    Filed: May 10, 1978
    Date of Patent: May 8, 1979
    Assignee: AGFA-Gevaert A.G.
    Inventors: Kurt Borowski, Friedrich Stumpf, Theodor Huber
  • Patent number: 4153351
    Abstract: For trick cinematography, a motion-picture camera is equipped with a pushbutton which upon actuation blocks or retards the windup of a film in a cassette while the film transport past an image gate continues. The advancing film, with or without exposure according to the desired effect (cross-fading or reverse filming), is deflected from an exposure gap in the cassette, either at the image gate or at a sound-recording head, into a loop received in an adjacent storage chamber from which it is subsequently withdrawn by reverse transportation under the control of a counter which registers the number of frames in the loop. The deflection of the film during the loop-forming phase may be effected by a baffle or by a perforation-engaging detent.
    Type: Grant
    Filed: May 1, 1978
    Date of Patent: May 8, 1979
    Assignees: Karl Vockenhuber, Hauser Raimund
    Inventor: Friedrich Stockl
  • Patent number: 4150884
    Abstract: A motion-picture camera optionally loadable with silent-film and sound-film cassettes has a reversible film-feeding mechanism including a reciprocable transport claw and a catch engageable with a takeup reel through a coupling within the cassette including a rewind stop. A spring-loaded stud close to the catch enables the rewind stop to be disengaged in a sound-film camera whereby the film can be transported backward for trick cinematography such as superposition of scenes. During the first run of such a double exposure, a step-down transmission can be activated to slow the windup of the film within its cassette if the latter is of the silent-film type, thereby creating a reserve length of film that can be rewound on the supply reel. In the presence of a sound-film cassette, as determined by a sensor which could be the aforementioned stud, this stepdown transmission is disabled inasmuch as the disengagement of the rewind stop allows the film to be reverse-driven without such reserve length.
    Type: Grant
    Filed: April 27, 1977
    Date of Patent: April 24, 1979
    Assignee: Bolex International SA
    Inventor: Willi Reichen
  • Patent number: 4143950
    Abstract: Motion picture camera, with an objective, in the light path of which, two exposure control devices, on the one hand a diaphragm and on the other hand a shutter, are adjustable by means of a common adjustment drive according to a predetermined program for changing of the light quantity which falls on a film per picture. An additional override, adjustment device is provided for at least one of said two exposure control devices for adjustment thereof independent of the predetermined program.
    Type: Grant
    Filed: May 30, 1978
    Date of Patent: March 13, 1979
    Assignees: Ing. Karl Vockenhuber, DDr. Raimund Hauser
    Inventor: Josef Schild
  • Patent number: 4140374
    Abstract: A sound cinecamera is provided with an intermittent film feeding motor, a continuous film driving means for sound recording, an operating means, a plurality of switch means which is operated by said operating means so as to control the ON and OFF as well as the driving direction of said film feeding motor, and a controlling means which is connected with said film feeding motor by said operating means so as to be driven in concert with said motor and controls an overlapping operation in co-operation with said switch means.
    Type: Grant
    Filed: August 26, 1977
    Date of Patent: February 20, 1979
    Assignee: Chinon Industries Incorporation
    Inventor: Yasuhiko Nakayama
  • Patent number: 4139282
    Abstract: A device is provided for indicating fading operation in cinecamera. A control circuit receives the scene light indicating voltage and a manually adjusted output voltage for operating a diaphragm driving means to adjust the aperture to a proper value for the scene brightness an RC circuit is connected to the diaphragm control circuit which selectively applys either a constant charging or discharging voltage to the diaphragm control circuit, this causes the control circuit to drive the diaphragm to continuously vary the aperture for effecting the fading-out and the fading-in of the scene. A first comparator receives the output voltage of the RC circuit and the output voltage of the diaphragm control circuit and produces a signal when both voltages are coincident.
    Type: Grant
    Filed: May 17, 1977
    Date of Patent: February 13, 1979
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Tomio Kurosu
  • Patent number: 4124283
    Abstract: A fade-in and fade-out device of an automatic servomechanism for controlling the diaphragm exposure of cinecamera. A differential amplifier having a first input voltage corresponding to the scene light and a second reference input voltage corresponding to the requisite exposure, produces a differential control voltage which is applied to the diaphragm during fade-in or fade-out.
    Type: Grant
    Filed: May 13, 1977
    Date of Patent: November 7, 1978
    Assignee: Copal Company Limited
    Inventors: Yasuo Shigeru, Tomio Kurosu
  • Patent number: 4106865
    Abstract: The light-sensitive negative-feedback diaphragm control system of the motion-picture camera includes a stepper-motor coupled to the diaphragm, and a control circuit generating stepper-motor drive pulses. The control circuit includes an oscillator having a time-constant circuit which establishes the repetition frequency of the drive pulses. m different repetition frequencies can be established for the drive pulses, using m semiconductor switches each connected to the time-constant circuit. A program-step counter counts program-step-change signals generated during film transport, and a "1" signal appears on successive ones of the counter outputs. The outputs include, in succession, a fade-out output group, a rewind output group, and a fade-in output group. Each such output group contains m outputs.
    Type: Grant
    Filed: September 1, 1977
    Date of Patent: August 15, 1978
    Assignee: AGFA-Gevaert, A.G.
    Inventor: Norbert Burgermann
  • Patent number: 4106864
    Abstract: The user selects a fadeover duration by selecting the number of pulses in a reference pulse packet registered by a reference counter. During film transport in either direction, a frame-pulse counter counts up a number of frame pulses equal to the number of pulses in the reference pulse packet, and then performs another frame-pulse counting cycle. Each frame-pulse counting cycle advances a program-step counter. Logic circuitry is responsive to the count on the program-step counter and, during the successive program steps, causes fade-out, film-rewind, and fade-in operations to be performed. The adjusting motor for the diaphragm operates at a speed inversely related to the number of pulses in the reference pulse packet, and the amount by which the adjusting motor changes the diaphragm setting during each frame-pulse counting cycle is always the same.
    Type: Grant
    Filed: August 25, 1977
    Date of Patent: August 15, 1978
    Assignee: AGFA-Gevaert, A.G.
    Inventor: Norbert Burgermann
  • Patent number: 4101209
    Abstract: The invention relates to a cine camera with a shutter and a release which can be moved in the manner of a sequence switch from an inoperative position into two different operative positions, the shutter being switched on in the first operative position which follows the inoperative position and a stopping down device being switched on in the second operative position of the release.
    Type: Grant
    Filed: September 8, 1976
    Date of Patent: July 18, 1978
    Assignees: Karl Vockenhuber, Raimund Hauser
    Inventor: Otto Freudenschuss
  • Patent number: 4094594
    Abstract: A movie camera has a film advance motor which can only operate when a relay is closed that is controlled by a transistor. This transistor can be operated by the release switch of the camera and by a circuit which senses the end of a fade-out cycle so that the film-advance motor is automatically stopped at the end of the fade-out cycle. To this end a variable diaphragm, which is provided with automatic light-adjusting circuitry is operated by a driving coil adjacent which is provided a damping coil that causes a control circuit to change the level of an output signal when the diaphragm aperture is fully closed so that at this time the film-advance motor is automatically stopped.
    Type: Grant
    Filed: April 12, 1976
    Date of Patent: June 13, 1978
    Assignee: Robert Bosch GmbH
    Inventors: Hermann Mayer, Hans-Friedrich Kiefer
  • Patent number: 4083630
    Abstract: The disclosure relates to a fade circuit for a motion picture camera of the type which includes an automatic exposure control. The fade circuit includes a light emitting diode which illuminates the light sensitive device of the automatic exposure control to augment the ambient light levels normally received by the light sensitive device. The intensity of the light emitted by the light emitting diode is controlled by a variable current source which provides the light emitting diode with continuously increasing or decreasing current for increasing or decreasing the intensity of the light from the light emitting diode. Fade-in is obtained as the light intensity of the light emitting diode is gradually decreased from an initial intensity sufficient to close the diaphragm opening to zero intensity to allow the diaphram to assume an opened condition corresponding to ambient light levels.
    Type: Grant
    Filed: July 24, 1975
    Date of Patent: April 11, 1978
    Assignee: Bell & Howell Company
    Inventors: Robert C. Mau, deceased, Erwin E. Figge
  • Patent number: 4073580
    Abstract: A fade photographing controlling apparatus for a cine or movie camera comprises a rotary member adapted for alternate rotation through 180.degree. in a first direction and in an opposite, second direction, and a cam member including first and second eccentric cam surfaces and adapted to be coupled with the rotary member for rotation therewith only when the rotary member rotates in the first direction. The initial rotation of the rotary member in the first direction is utilized for fade out photographing, and the succeeding rotation of the rotary member in the second direction is used to reversely feed the film portion which has been used during the fade out photographing, while a final rotation of the rotary member in the first direction is utilized for fade in photography on the same film portion.
    Type: Grant
    Filed: June 23, 1976
    Date of Patent: February 14, 1978
    Assignee: Sankyo Kogaku Kogyo Kabushiki Kaisha
    Inventor: Toshitatsu Kawatsu
  • Patent number: 4065209
    Abstract: The invention is directed to a movie camera that is designed for loading with at least two different types of cassettes both of which are designed for accommodation together within the interior of the camera but which are provided with exterior configurations that are characteristic of each type of cassette, while additionally, at least one of the two types of cassettes is provided with a releasable rewind stop for at least one of the two reels of film contained in the cassette as well as being provided with a device for effecting the release of the rewind stop which is controlled by an actuating member supported on the camera.
    Type: Grant
    Filed: March 29, 1976
    Date of Patent: December 27, 1977
    Assignees: Karl Vockenhuber, Raimund Hauser
    Inventor: Otto Freudenschuss
  • Patent number: 4045132
    Abstract: In a film rewinding device for a movie camera which is capable of selective use of both the type A magazine provided with a non-releasable anti-backup mechanism on the exposed film take-up shaft and the type B magazine provided with an externally releasable anti-backup mechanism on the film take-up shaft, the film rewinding device comprises a pin to indicate the type of magazine loaded, and for locking the anti-backup mechanism for the type B magazine, to be released when this type of magazine is loaded; a counting gear to count the film footage of the forward or reverse feed, and a connecting gear. The present device makes it possible to selectively use rewinding patterns possessing the advantages of two types of magazines and to employ special photographing techniques for overlaps, superimposition and reverse shooting, in suitable combination.
    Type: Grant
    Filed: April 9, 1975
    Date of Patent: August 30, 1977
    Assignee: Nippon Kogaku, K.K.
    Inventor: Yozo Iida
  • Patent number: 4043649
    Abstract: A motion-picture camera has a diaphragm whose aperture size is inversely proportional to the frequency fed to the diaphragm control servo-motor. This frequency is normally maintained between a predetermined upper limit and a predetermined lower limit. For fade out the frequency is rapidly decreased to the lower limit and thereafter regularly increased to the upper limit whereas for fade in the frequency is rapidly increased to the upper limit and thereafter regularly decreased to the lower limit. During rewind the frequency is maintained between the limits. This frequency increase and decrease can be effected by connecting oscillators of different frequency to the motor in a stepwise fashion, or by varying an impedance element of the tuned circuit of the oscillator that operates the diaphragm motor. Resistors and/or conductors strips on a control or program wheel can be used to carry out the fade out and fade in.
    Type: Grant
    Filed: March 8, 1976
    Date of Patent: August 23, 1977
    Assignee: AGFA-Gevaert, A.G.
    Inventor: Helmut Mayr
  • Patent number: 4030820
    Abstract: A fading device for a motion picture camera includes a pair of sectors rotated with respect to each other to vary the angle of a light passing section formed thereby to obtain a fade-in or fade-out effect. The sectors are rotated relatively to each other by means of a drive mechanism operated by a motor by way of a change-over mechanism which is operable to change the direction of the relative rotation of the sectors. An indicator is connected with the change-over mechanism to indicate whether the fade-in or fade-out is possible in accordance with the situation of the sectors.
    Type: Grant
    Filed: December 5, 1975
    Date of Patent: June 21, 1977
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventor: Tetsuo Nishizawa
  • Patent number: 4015119
    Abstract: To inform the operator of a motion picture camera of under-exposure and the status of a fade operation, an indicator circuit is provided. The indicator circuit is in circuit with an automatic exposure control system which adjusts the diaphragm for correct film exposure under varying light conditions and an electronically controlled fade system which adjusts the diaphragm for a fade-in and fade-out sequence independently of the varying light condition on the subject.
    Type: Grant
    Filed: December 24, 1975
    Date of Patent: March 29, 1977
    Assignee: Nihon Beru-Haueru Kabushiki Kaisha
    Inventor: Teruhiko Miyake
  • Patent number: 4006976
    Abstract: Fade-in and fade-out device used in a cinecamera having an automatic exposure control circuit including a photoelectric element receiving light from scene through the diaphragm of the taking lens for generating an output voltage indicative of the scene brightness, a capacitor for generating an output voltage used as a reference voltage and a servoamplifier for comparing the output voltages of the photoelectric element and the capacitor so that an output, the sense of which is dependent on the values of the outputs of the photoelectric element and the capacitor and which is continuingly generated until both the outputs of the photoelectric element and the capacitor become equal to each other, is supplied to an actuating means for the diaphragm of the taking lens so as to control the same for the proper exposure.
    Type: Grant
    Filed: July 16, 1975
    Date of Patent: February 8, 1977
    Assignee: Copal Company Limited
    Inventor: Yasuo Ishiguro
  • Patent number: 4006975
    Abstract: Pressing of the camera release button causes start of the film transport and automatic setting of the diaphragm for a normal exposure. When fade-over switch is closed, a forward-reverse counter is started. When the count on the counter reaches 31, a first AND-gate switches a first JK flip-flop to a second state wherein an additional resistor is inserted in the normally balanced diaphragm control circuit thereby unbalancing same and causing the closing of the diaphragm to commence. When the count on the counter reaches 63, another AND-gate switches additional JK flip-flops for reversing both the film transport and the counting direction of the counter. When the counter has counted down to a predetermined number, further logic circuits cause a stoppage of the film transport and stopping and resetting of the counter so that reactivation of the release button automatically starts the fade-in.
    Type: Grant
    Filed: July 23, 1975
    Date of Patent: February 8, 1977
    Assignee: AGFA-Gevaert, A.G.
    Inventors: Eduard Wagensonner, Alfred Winkler
  • Patent number: 3973841
    Abstract: A motion picture camera wherein the trigger of the camera release is movable from an extended position to a second position in which it starts the camera motor, and beyond the second position to thereby cause an auxiliary tooth to enter a gap in the annulus of teeth at the periphery of a program wheel which forms part of the mechanism for making exposures with dissolve. The auxiliary tooth is thereby moved into the path of cyclical movement of the pallet on a pawl which is driven whenever the motor is on whereby the pallet can move the program wheel from a starting position and thereupon cooperates with the teeth of the program wheel to rotate the latter through one revolution during which the program wheel initiates the making of exposures with fade-out and subsequent rearward transport of film frames which were exposed with fade-out, and prepares the motor for renewed forward transport of such film frames with simultaneous exposure with fade-in.
    Type: Grant
    Filed: July 14, 1975
    Date of Patent: August 10, 1976
    Assignee: AGFA-Gevaert, A.G.
    Inventors: Rolf Gehlert, Friedrich Winkler
  • Patent number: 3972604
    Abstract: A motion-picture camera having exposure and sound-recording structures past which the film is transported by a pair of film-transporting structures, respectively, at least one of which is driven by a variable speed electric motor. The film is transported both forwardly and rearwardly and forms between the exposure and sound-recording structures a loop from which the film is continuously transported to the sound-recording structure and to which the film is transported in a stepwise manner from the exposure structure.
    Type: Grant
    Filed: September 30, 1974
    Date of Patent: August 3, 1976
    Assignee: Kabushiki Kaisha Yashica
    Inventors: Hirofumi Yoshimura, Toyonori Higuma, Noriaki Itoo
  • Patent number: 3966312
    Abstract: A bridge circuit contains a photoelectric resistor positioned behind the diaphragm and thus having a resistance varying as a function of the light falling on the film. A second arm of the bridge circuit contains a resistor. The bridge circuit output is connected to the inputs of a differential amplifier whose output controls a step motor which adjusts the size of the aperture until the bridge is balanced. For fade-out, an additional resistor is inserted in the second arm by opening a short-circuiting switch, thus causing the bridge to become unbalanced and the step motor to change the aperture until it is again in balance. This balance will take place at a predetermined low illumination suitable for fade-out. Closing the switch will result in fade-in, namely an opening of the aperture until the circuit is again in balance. The output signal from the bridge circuit thus controls the aperture even during fade-in and fade-out.
    Type: Grant
    Filed: December 5, 1974
    Date of Patent: June 29, 1976
    Assignee: AGFA-Gevaert, A.G.
    Inventors: Eduard Wagensonner, Volkmar Stenzenberger
  • Patent number: 3950083
    Abstract: A motion picture camera capable of recording sound simultaneously with film exposure and capable of carrying out fade-out as well as fade-in operations. A control is provided for automatically reducing the audio level during a fade-out operation and for automatically increasing the audio level during a fade-in operation.
    Type: Grant
    Filed: October 18, 1974
    Date of Patent: April 13, 1976
    Assignee: Kabushiki Kaisha Yashika
    Inventors: Hirofumi Yoshimura, Toyonori Higuma, Noriaki Itoo
  • Patent number: 3945719
    Abstract: In a motion picture camera which permits selective use of a magazine A of the type having an unreleasable reverse-preventing means provided on a take-up shaft for taking up thereon exposed film and a magazine B of the type having an extraneously releasable reverse-preventing means provided on a take-up shaft and which has a take-up gear rotatable in response to a motor and a member secured to the gear for rotating the take-up shaft with rotation of the gear, there is provided detector means displaceable to a first position upon insertion of the magazine A and to a second position upon insertion of the magazine B to identify the magazine inserted. The take-up gear is integrally formed with the detector means for displacement in the axial direction thereof.
    Type: Grant
    Filed: February 21, 1975
    Date of Patent: March 23, 1976
    Assignee: Nippon Kogaku K.K.
    Inventor: Yozo Iida