Ricoh Company, Ltd.

Susumu Iguchi

Kazumasa Aoki

Yoshimi Ohno

Daisuke Hata

Takayuki Hatase

Masamichi Furukawa

Takao Yamaguchi

Hirofumi Horigome

Yoshihiko Shimura

Akira Ueno

Hiroshi Takeda

Kenji Koyama

Yoshio Fukushima

Toshiaki Nakahira

Yoshio Serikawa

Kunihiko Araki

Satoshi Yamane

Yoshimi Ono

Koichi Nishi

Shigeru Mitsu

Tadafumi Ohguro

Hideaki Akiyama

Yukihisa Narazaki

In a range finder, a capacitor for light emission is charged by turning off first and second switching elements and turning on third and fourth switching elements before light is emitted from a light emitting diode. A sum of a charging voltage of the capacitor for light emission and the voltage of a direct current power source is applied to the light emitting diode by turning on the first and second switching elements and turning off the third and fourth switching elements when light is emitted from the light emitting diode. At this time, an operation of the second switching element is controlled with a constant electric current by a constant current control circuit constructed by a transistor, a resistor for current limitation, a diode, etc. so that an electric current flowing through the light emitting diode is constant and a light emitting amount of the light emitting diode becomes constant.

Range finder

A flashing apparatus of an automatic light-adjusting type for illuminating a photographed object by discharging a charge charged to a main capacitor from a light emitting tube has an energy amount detector for detecting an energy amount applied to the light emitting tube from the main capacitor; an energy amount setting device for setting an amount of discharged energy of the main capacitor corresponding to a quantity of light required to illuminate the photographed object; a comparator for comparing the energy amount detected by the energy amount detector with the energy amount set by the energy amount setting device; and a light emission stopping device for stopping light emission of the light emitting tube by a signal outputted from the comparator when the comparator detects that the discharged energy amount of the main capacitor is in conformity with the set amount of the energy amount setting device after the light emission is started. The flashing apparatus may further has a voltage detector constituting the energy amount detector and detecting a voltage applied to the light emitting tube from the main capacitor; an electric current detector for detecting an electric current flowing through the light emitting tube; a multiplying device for multiplying the detected voltage by the detected electric current; an integrator for integrating the multiplied results; etc.

Flash control based on calculated required flash energy

An auto-focus arithmetic device suitable for use in a photographic camera is provided. The device includes a photographic lens which is movable along a predetermined optical axis and a CCD for detecting light coming from a subject of interest through the lens. An arithmetic unit for determining the direction and amount of movement of the lens with respect to the subject of interest based on a detection signal from the CCD is provided. The arithmetic unit includes an integer portion calculating sub-unit for calculating an integer portion of the detection signal and a fractional portion calculating sub-unit for calculating a fractional portion of the detection signal. The fractional portion calculating sub-unit remains deactivated as long as the detected amount of discrepancy from the in-focus condition is larger than a predetermined level; however, it is activated when the detected amount of discrepancy becomes equal to or less than the predetermined level. In this manner, in accordance with the present invention, the integer and fractional portion calculating sub-units are used alternately.

Auto-focus arithmetic device

An apparatus for controlling a motor in a camera including, a motor drive unit for driving the motor in a prescribed sequence, a braking device for applying the brakes on the motor in accordance with the prescribed sequence, and a speed detecting unit for monitoring the speed of the motor and permitting initiation of the next action only after the speed of the motor, in consequence of application of the brakes by the braking device, is brought to a level incapable of obstructing the next action.

Apparatus for controlling a motor in a camera

An automatic focusing control system includes a focus detecting light detector, a rangefinder, a lens driver, a manual range setting unit, a mode setting unit, and a control unit. When a manual mode is selected by the mode setting unit, the control unit applies a lens driving signal from the manual range setting unit to the lens driver unit to drive a lens. When an automatic mode is selected by the mode setting unit, the control unit operates the lens driver unit to drive the lens based on a measured distance at the time distance measurement is possible, applies the lens driving signal from the manual range setting unit to the lens driver unit at the time distance measurement is impossible, and operates the lens driver unit to drive the lens based on the measured distance at the time distance measurement becomes possible from a condition in which distance measurement is impossible.

Automatic focusing control system

An image signal amplifier circuit includes an amplifier for amplifying an image signal from a focusdetecting self-scanned image sensor, and a monitor photodetector for detecting the brightness of an object to be photographed. The amplification degree of the image signal is controlled by an automatic gain controller in the amplifier based on an output signal from the monitor photodetector so that the image signal as amplified will be of a constant level. An offset voltage is added to an output signal from the amplifier.

Focus detecting device and image signal amplifier circuit therefor

A battery check device for checking a battery of a camera having at least a storoboscopic flash unit is disclosed, which functions to compare a first reference time with a charging time of a main capacitor of the flash unit and, when the charging time becomes longer than the reference time, to indicate it as showing a considerable consumption of the battery. The device may have a second reference time which is longer than the first reference time so that the battery is disconnected from the flash unit when the charging time is longer than the second reference time. Thus, the battery can be checked even during a usage of the flash unit and prevented from being discharged completely.

Battery check circuit of electronic strobe flash unit of camera

A charge-coupled device has a plurality of photodiode arrays, a plurality of storage electrodes, a pluratity of shift gates, a plurality of reset terminals, and a plurality of shift terminals, which can be operated at different timings. Object images detected by the charge-coupled device at a certain time interval are compared for camera shake detection.

Charge-coupled device for automatic focusing and camera shake detector

A device for indicating the current focus condition of an auto-focus system for use in a camera and the like includes an indication processing circuit interposed between an arithmetic processing circuit, which receives distance information to an object of interest, and an indicator/controller. The indication processing circuit allows to maintain the detected in-focus condition sufficiently long so that an observer can judge the proper focus condition even if the object is in slight motion, or the camera is being held by hands.

Focus condition indicating device of an auto-focus system

A film advancing system of a camera in which a roll of film inside a film cartridge is first wound to a spool and then the film is rewound into the cartridge one frame from another after each photographic operation is provided. The system includes a reversibly rotatable motor the drivement and rotational direction of which are automatically controlled depending upon various conditions of the camera to implement required advancement of the film.

Film feeding system of a camera

An address counter sequentially addresses locations in a shift register or random access memory in which a waveform is stored in digital form to display the waveform on a cathode ray tube. Several magnification ranges are provided so that a selected portion of the waveform may be viewed in magnified form. A manually controllable position counter selects the portion of the magnified waveform for viewing in such a manner that the center of the portion will remain in the center of the cathode ray tube when the system is switched between magnification ranges. The position counter is an up-down counter which is driven by a same clock pulse generator which drives the address counter. A variable frequency divider is provided between the clock pulse generator and the position counter in such a manner that the position counter is driven at a convenient speed regardless of the magnification range. Two manually controllable mark counters similar to the location counter are also driven from the clock pulse generator, and indicate memory locations for which respective markers are to be displayed on the cathode ray tube. The contents of the memory location corresponding to the first of the markers is displayed in digital form, and the time difference between the markers is also measured and displayed in digital form. Variable frequency dividers provide magnitude and time scaling for the digital displays, and also ensure movement of the markers on the cathode ray tube at a convenient speed regardless of the magnification range. The frequency dividers are switched so that the address and mark counters are driven at low speed when the selected portion for magnification and marks are addressed and at high speed at other times.

Waveform analysis system

Voltage comparators for actuating a camera shutter and a low-light indicating lamp respectively have inputs connected to junctions between photocells and resistors so as to be controlled in response to the light level. The voltage comparator for the low-light indicator energizes the indicator when the light level is below a low-light value from the time the shutter release button is partially depressed until the time the shutter is closed after the exposure. The voltage comparator for the shutter produces a shutter opening signal to open the shutter for the required length of time based on the light level. The output of the voltage comparator for the shutter is connected through a diode to the input of the voltage comparator for the low-light indicator so that the low light indicator is deenergized when the shutter is closed.

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Yokohama, Japan

Susumu Iguchi