Canon Kabushiki Kaisha

Texas Instruments Corporation

Canon Inc.

Ryuji Tokuda

Ryoichi Suzuki

Masahiko Ogawa

Shuichi Tamura

Tokuichi Tsunekawa

Masanori Uchidoi

Bernhard H Andresen

Takashi Kobe

Yoshihiro Harunari

Hiroyoshi Tsuzuki

Tetsuya Taguchi

Yukio Mashimo

Tomonori Iwashita

Michio Hirohata

Akira Egawa

Noritaka Mochizuki

Mutsuhide Matsuda

Akio Sunouchi

Masanori Ohtsuka

Hikaru Hoshi

Michitaka Setani

Masanori Sakuranaga

Kenichi Kumazawa

A display device includes a transparent substrate, a plurality of electroluminescent elements arranged on the transparent substrate, transparent members respectively covering the electroluminescent elements, and reflection films formed respectively on the surfaces of the transparent members. Each of the electroluminescent elements is formed by sequentially laying a transparent electrode, an electroluminescent layer and a reflector electrode on the transparent substrate. Each of the transparent members has a profile of a frustum of pyramid or cone, or partly has a curved surface showing a positive curvature and a curved surface showing a negative curvature at the portion held in contact with the transparent substrate.

Display device having conical transparent members covering electroluminescent elements

In a distance measuring device which has a semiconductor position sensor or the like employed as a light receiving element and which produces two different signals corresponding to the incident angles of a light coming from an object, the signals from the light receiving element are supplied, one after another, to a dual-slope type integrator such as a Miller integrator. A length of time required for reverse integration of the dual-slope type integrator is measured. Distance to the object is computed on the basis of the measured time.

Distance measuring device

An input circuit which converts currents produced from a plurality of photo-sensitive elements arranged in a distance measuring apparatus. The input circuit has a switching element series connected to at least one of the photo-sensitive elements. When the switching element is operated, the output current of one of the photo-sensitive elements is supplied to a converting circuit which converts current into a voltage. Only one converting circuit is present. The output of the converting circuit is produced in a time series to a computing circuit. The computing circuit processes the signal thus received and produces a signal corresponding to an object distance.

Input circuit for distance measuring apparatus

A motor drive control circuit for a camera comprises means for comparing a power supply voltage with a predetermined voltage; means for holding information obtained by the comparison; and a timer circuit which causes an output signal to be generated after the lapse of a predetermined period of time. With exception of the time at which the power supply to the motor is started, the power supply voltage obtained during the process of power supply to the motor is compared with the predetermined voltage. The information thus obtained is retained and various control operations are performed on the basis of the information retained.

Motor drive control circuit

In the disclosed battery voltage checking apparatus a first detector detects a first battery voltage level and a second detector detects a second battery voltage level. The first detector produces a signal to instruct the operator to replace the battery when the voltage level of the battery is below the first battery voltage level. Another signal is produced to inhibit camera operation when the battery voltage is below the second battery voltage level. The apparatus includes a circuit arranged to cause the first and second detectors to simultaneously detect the battery voltage level and another circuit arranged to process the signal produced from the first detector before processing the signal from the second detector.

Battery voltage checking apparatus

A camera provided with a display device that displays changing of the coupling range of a strobe as the amount of charge stored on a main capacitor in the strobe changes, that is, changing of the target area for a proper exposure in stroboscopic photography, and displays an object distance obtained by the auto-focus means in a combined form.

Camera with a display device for displaying both object distance

A shutter release device designed so that at the time of the self-timer photographing, the self-timer circuit is operated by a depression of the shutter button which closes the switch associated with the shutter button, the self-timer circuit is made non-operative by closing the above switch with re-operation of the shutter button during the self-timer operation so that the shutter release operation can immediately be carried out.

Shutter release device

An active type automatic focusing device which has a signal projecting means and an electromagnetic means for starting a focal point adjusting action actuated by a power supply to the electromagnetic means and is provided with an inhibiting means which inhibits the power supply to the signal projecting means at least during a period in which a current flows to the electromagnetic means for actuating the device.

Automatic focusing device

An exposure control device for a camera wherein a current produced from a light sensitive element in proportion to the quantity of light incident on the element is logarithmically suppressed. A suppressed voltage obtained from this current to which voltage is added a voltage which is substantially proportional to absolute temperature and is produced according to encoded film sensitivity information expressed in the APEX system. The voltage resulting from the addition is converted into a current and expanded. The degree of an exposure is controlled on the basis of the expanded current.

Exposure control device for camera

To accurately check a battery of a camera, a battery checking operation must be performed under maximum load current, namely, the load current of a shutter release magnet or the like. The invention avoids the effect of a current through the magnet triggering a photographic operation of the camera during a battery check by having currents flow to a plurality of selected loads of the camera, such as light emitting diodes, etc., instead of through the magnet. The plurality of loads are preselected to draw the total sum of load currents nearly equal to the maximum load current. A battery check can be performed without applying a drive current to the largest load and yet the accuracy of the battery check thus obtained equals that of the accuracy obtainable with the largest load.

Battery check device for camera

In the disclosed indicating apparatus, an alarm operates an indicator when a light measuring system measures abnormal lighting. A latch latches the alarm in response to a shutter release to indicate that the shutter is open. A switchover device changes the alarm signal in response to the end of an exposure. According to one embodiment of the invention, the indicator displays the alarm condition while the shutter is open. According to another embodiment of the invention, the indicator assumes a condition constituting a substate of the alarm condition.

Indicating apparatus for camera

A brightness warning device for a camera is disclosed, which has a warning means and a detecting circuit for detecting a charge level of the timing capacitor in the exposure amount adjusting circuit of the aforesaid camera upon attainment of the detecting level to a predetermined value to produce an output signal driving the aforesaid warning means.

Brightness warning device for camera

The disclosed camera sequentially controls the operations of two or more units, for example, an exposure control circuit and a film advance motor. An arrangement senses whether or not an operation has been completed normally and stores the result. When the succeeding operation is to start, the condition of the storage is sensed. If the memory indicates that the operation has not been normal, then the following operation is disabled.

Electrically operated camera and disabling device therefor

Disclosed is a temperature compensation system for light measuring circuits. Said system compensates for the change, over temperature, of the output of the light measuring circuit by applying a bias source with a predetermined temperature coefficient. The system is designed so the bias voltage source is derived from the V.sub.BE (base to emitter voltage) difference between a pair of transistors, which difference is generated by the difference of current density at the junction of the pair of transistors obtained by flowing a pair of currents with a constant ratio independent of temperature.

Temperature compensation system of light measuring circuit

In the disclosed driving circuit for a coil, particularly for driving a coil in a device such as a camera whose shutter blades are driven with electro-magnetic force generated by a current flowing through the coil and a magnetic field in which the coil is positioned, a voltage approximately proportional to the absolute temperature is applied across the terminals of the coil so as to produce temperature compensation of the coil current.

Growing community of inventors

Tokyo, Japan

Ryuji Tokuda