Photoflash Patents (Class 315/241P)
  • Patent number: 6167199
    Abstract: In an information transmitting apparatus capable of transmitting information by using flash light emission of a flash light emission tube, communication data is detected at timing synchronized with a predetermined period and, when the detected communication data indicates a light emission instruction, a predetermined light emission signal is formed and outputted to cause the flash light emission tube to make light emission, wherein a time interval from a point of time at which the light emission instruction has been detected to a point of time at which the light emission signal is outputted is varied according to a time interval from a point of time at which the preceding light emission has been performed to a point of time at which the light emission instruction for the current light emission is detected, so that the intervals of flash light emission are adjusted.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: December 26, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hajime Fukui
  • Patent number: 6157140
    Abstract: A plurality of energy emitters, such as flash tubes for visibile light or speakers for audio emissions, are placed in communication with an appropriate trigger circuit, one circuit for each of the energy emitters. Each trigger circuit is placed in communication with a timing circuit which communicates sequentially with each of the trigger circuits and is in communication with means to adjust an input energy level delivered to the timing circuit. When a trigger circuit is in communication with the timing circuit, energy is delivered to the trigger circuit to cause the transmission of input energy through the trigger circuit sufficient to cause the emission of energy by the energy emitter. A plurality of energy collectors appropriate to the nature of the emitted energy, are maintained in spatial arrangement to the energy emitter for the purpose of recovering spurious or nonfocused energy released by the emitter and from other sources of spurious energy within the system.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: December 5, 2000
    Inventor: Joseph Edward Rodrigue
  • Patent number: 6150770
    Abstract: In a flash apparatus capable of making high-speed repeating light emission, a self-maintaining switch element provided for various purposes is prevented from erroneously operating due to the high-speed repeating light emission, by providing a circuit element which reverse-biases a control electrode of the self-maintaining switch element.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: November 21, 2000
    Assignees: Canon Kabushiki Kaisha, West Electric Co., Ltd.
    Inventors: Shinji Hirata, Hideaki Kondo
  • Patent number: 6147460
    Abstract: In a power supply device for a flash apparatus having the primary winding side of a transformer and an oscillation-controlling switching element connected in parallel to a power supply and the secondary winding side of the transformer connected to a main capacitor through a rectifier element, a current-to-voltage conversion circuit is arranged to output a voltage signal according to a current flowing from the secondary winding side of the transformer to the main capacitor, and the main capacitor is charged by on-off controlling the switching element according to the voltage signal outputted from the current-to-voltage conversion circuit.
    Type: Grant
    Filed: May 25, 1999
    Date of Patent: November 14, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshiro Ichihara
  • Patent number: 6111364
    Abstract: A device and method that inhibits the ability of photographic equipment from obtaining a recognizable picture upon its recording media, of areas of a vehicle equipped with this invention. The leading edge or beginning of the photographic equipment's photoflash is detected by the photoflash detector cicuit group (50). A xenon reply flash (30) is immediately output towards the photographic equipment's general location, for the remainder of the photographs exposure time, rendering sections of the photograph unrecognizable.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: August 29, 2000
    Inventors: Jerry L. Davis, Steven S. Davis
  • Patent number: 6104144
    Abstract: A conventional stroboscope circuit in use for a film camera has encountered with problems that charging of a main capacitor is incapable when other functions of the camera are operated and that a charging operation is delayed. To solve aforesaid problems, the present invention is to charge the capacitor C1 for a flashlight illumination by a use of a stroboscope charging circuit 1. During that, a usual charging operation is performed by feeding a higher current which flows through a transistor Q1, in a manner wherein a control signal CTL is switched to an H (a high) level status. When the other functions of the camera are operated on the contrary, the charging is performed by feeding a lower current which flows through a resistor R1, wherein the control signal CTL is switched to an L (a low) level status.
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: August 15, 2000
    Assignee: Stanley Electric Co., Ltd.
    Inventors: Takayuki Yoneya, Keizo Sekido
  • Patent number: 6081076
    Abstract: A fill-in light emitting apparatus having an illuminating mechanism for emitting illumination light whose color temperature can be varied; a color temperature metering mechanism for measuring the color temperature of the external light; and a color temperature controlling mechanism for varying the color temperature of the illumination light in accordance with color temperature data measured by the color temperature metering mechanism.
    Type: Grant
    Filed: August 20, 1997
    Date of Patent: June 27, 2000
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventor: Kimiaki Ogawa
  • Patent number: 6072281
    Abstract: A fill-in light emitting apparatus having an illuminating mechanism for emitting illumination light whose color temperature can be varied; a color temperature metering mechanism for measuring the color temperature of the external light; and a color temperature controlling mechanism for varying the color temperature of the illumination light in accordance with color temperature data measured by the color temperature metering mechanism.
    Type: Grant
    Filed: August 21, 1997
    Date of Patent: June 6, 2000
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventor: Kimiaki Ogawa
  • Patent number: 6066926
    Abstract: An electronic flash device in which a voltage of a power supply battery is boosted to be supplied to a load, includes a first oscillation portion of self-excited type, a second oscillation portion of separately-excited type, and a changeover portion which performs a changeover between causing the first oscillation portion to operate and causing the second oscillation portion to operate, according to a condition of the load.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: May 23, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masanori Yamada
  • Patent number: 6064159
    Abstract: In a power-saving stroboscopic device, a main capacitor is not completely discharged even in full light emission, so that a predetermined amount of charge can be left in a main capacitor, in order to save power in a stroboscopic circuit of the device. A light emission unit of the stroboscopic device can perform full light emission and flat emission based on a period of light emission time set by predetermined conditions. The stroboscopic device comprises a light emission control unit and a control unit for controlling a period of light emission time, so that a residual voltage in a main capacitor in the stroboscopic circuit is higher than a residual voltage after full light emission, in order to improve the charging efficiency after the full light emission.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: May 16, 2000
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Hiroshi Yamada, Akira Inoue
  • Patent number: 6054814
    Abstract: In a flash circuit for a single use camera, a minimum residual charge voltage level is maintained on a flash capacitor to ensure availability of an energy source to operate an auxiliary circuit, such as an optical data recording circuit, even after prolonged periods of non-use of the camera. This minimum charge voltage level is maintained by provision of a DC circuit path from the camera battery via the charger circuit and flash power rectifier diode to the flash capacitor. Automatic restart of the flash charging circuit upon closing of the flash trigger switch is assured by connecting the charging circuit start terminal to the trigger switch by means of a normally reverse biased re-start diode that isolates the start terminal from the flash capacitor voltage on the trigger circuit at all times when the flash trigger switch is open.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: April 25, 2000
    Assignee: Eastman Kodak Company
    Inventor: Douglas W. Constable
  • Patent number: 6049175
    Abstract: A light transmitting arrangement includes a light emitting device, for example a light emitting diode and an arrangement for peaking the current through the light emitting device upon switching on and/or off. The peaking arrangement includes a peaking network which is arranged in parallel with a light emitting device and which is a passive network.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: April 11, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Gunnar Forsberg
  • Patent number: 6034486
    Abstract: The present invention relates to an electronic flash device which, even if the charged voltage of a main capacitor is low, can securely effect a trigger operation by making a trigger voltage higher than the charged voltage of the main capacitor.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: March 7, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hajime Fukui
  • Patent number: 6011359
    Abstract: The present invention discloses a multiple flash/single lamp circuit for fast sequential strobing. More particularly, the present invention comprises a flashlamp, a pair of capacitors, a voltage multiplier and regulator to charge the capacitors, a pair of trigger circuits to discharge the capacitors and a controller to selectively activate each trigger circuit to activate the flashlamp.
    Type: Grant
    Filed: January 16, 1998
    Date of Patent: January 4, 2000
    Assignee: Acushnet Company
    Inventor: Charles A. Days
  • Patent number: 6005352
    Abstract: An electronic flash device includes a first DC--DC converter circuit of separately-excited type, a second DC--DC converter circuit of separately-excited type, a capacitor to be charged by the first DC--DC converter circuit and the second DC--DC converter circuit, and a discharge tube which converts charging energy charged to the capacitor into light energy. The first DC--DC converter circuit includes a first switching element having a first control electrode, and an a first oscillation transformer to which energization is controlled by the first switching element. A first control pulse signal is supplied to the first control electrode. The second DC--DC converter circuit includes a second switching element having a second control electrode, and an a second oscillation transformer to which energization is controlled by the second switching element. A second control pulse signal is supplied to the second control electrode.
    Type: Grant
    Filed: December 17, 1997
    Date of Patent: December 21, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yukio Odaka
  • Patent number: 5990631
    Abstract: In a current cut-off type automated stroboscope circuit which controls a flashlight intensity by cutting off the current flowing through a flash lamp, a high-speed semiconductor switching device inserted in series with respect to the stroboscopic tube has been encountered up to now with malfunction and breakdown problems induced by chattering. To solve aforesaid problems, the present invention is to provide a xenon tube 1 with an IGBT 2 connected in series with respect to the xenon tube 1. The gate electrode of the IGBT is connected to two pnp-type transistors Q1 and Q2 substantially inbetween, both transistors of which are connected in series with respect to each other. The IGBT is controlled by turning on and turning off of the transistors Q1 and Q2. Furthermore, a time constant circuit which is formed of a capacitor C1 and a resistor R1 is connected to the transistor Q1. A gate voltage is applied to the IGBT 2 only for a certain period of time (one shot) which is defined by a time constant of CR product.
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: November 23, 1999
    Assignee: Stanley Electric Co., Ltd.
    Inventors: Tatsuya Hioki, Keizo Sekido
  • Patent number: 5982114
    Abstract: A control apparatus for a copying machine or the like, has a halogen lamp for exposing an original, a detection circuit for monitoring a turn-on voltage of the lamp, a comparator for comparing the monitored turn-on voltage with a reference value, a microcomputer having an internal timer, and a memory for storing a phase control amount for a previous exposure operation. The light amount of the halogen lamp can be converged to a target value within a predetermined period of time and without adverse influence of turn ON/OFF operations of other loads such as a motor.
    Type: Grant
    Filed: December 9, 1993
    Date of Patent: November 9, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshiaki Takayanagi
  • Patent number: 5956535
    Abstract: In a flash device arranged to perform flat emission by detecting the intensity of light emission of a discharge tube during process of the light emission and by controlling the intensity of light emission to become almost constant during process of the light emission, the flat emission is adequately performed by varying a detection level for the intensity of light emission.
    Type: Grant
    Filed: February 25, 1997
    Date of Patent: September 21, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kei Tohyama
  • Patent number: 5896014
    Abstract: A fill-in light emitting apparatus having an illuminating mechanism for emitting illumination light whose color temperature can be varied; a color temperature metering mechanism for measuring the color temperature of the external light; and a color temperature controlling mechanism for varying the color temperature of the illumination light in accordance with color temperature data measured by the color temperature metering mechanism.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: April 20, 1999
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventors: Kimiaki Ogawa, Tahei Morisawa
  • Patent number: 5892332
    Abstract: On one side, a high-pressure gas discharge lamp (10) is connected, by way of the secondary winding (16) of an ignition transformer (14), to a line (11) and, on its second side, to a second line (12). It is therefore connected to a first voltage U.sub.1. A third line (13) delivers a further voltage U.sub.2. The ignition energy is supplied with the aid of a pulse. For this purpose, a spark gap (17) is provided in series with the primary winding (15), which gap abruptly becomes conductive when the breakdown voltage is attained. A first capacitor (18) that is charged by the voltage U.sub.2 by way of a resistor (20) connected in series is disposed in parallel to the first capacitor. The series connection of a second capacitor (19) and a diode (22) is provided in parallel to the first capacitor. The connecting point of the second capacitor and the diode is connected to the second line (12) by way of a resistor (21). This second capacitor 19 is charged by the voltage U.sub.1.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: April 6, 1999
    Assignee: Robert Bosch GmbH
    Inventors: Ulrich Drews, Bernd Rothfuss, Thomas Kienzler
  • Patent number: 5869936
    Abstract: A strobe device according to the present invention includes: a main capacitor; and step-up means including at least one step-up capacitor, the at least one step-up capacitor being rapidly charged via a flash discharge tube in an ionization state, a charged voltage of the at least one step-up capacitor being superimposed on a charged voltage of the main capacitor and applied across the flash discharge tube at least via an insulated gate bipolar transistor and a restriction resistor coupled in series with the flash discharge tube.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: February 9, 1999
    Assignee: West Electric Company, Ltd.
    Inventors: Katsumi Horinishi, Takanaru Kobayashi
  • Patent number: 5842047
    Abstract: A strobe light which emits light by supplying a flash discharge tube with the electric charge stored in a main capacitor uses an aluminum-electrolytic capacitor having a dissipation factor (tan.delta.) of 0.03 or lower, and has voltage controlling means for setting the charge completion voltage of the aluminum-electrolytic capacitor at a predetermined value within 265.+-.35 V.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: November 24, 1998
    Assignee: West Electric Company, Ltd.
    Inventors: Hisashi Ogura, Katsumi Ogisako
  • Patent number: 5814948
    Abstract: A flash circuit for a low cost camera in which a voltage dependent resistor is employed as a flash capacitor charge voltage sensing device to perform a control effect in the flash circuit, such as turning on a flash ready indicator light or activating a oscillation terminating device to arrest self oscillations in a flash charging circuit.
    Type: Grant
    Filed: January 14, 1997
    Date of Patent: September 29, 1998
    Assignee: Eastman Kodak Company
    Inventor: Paul Teremy
  • Patent number: 5780976
    Abstract: This invention is designed to reduce the number of parts in the circuits of a constant-voltage automatic charging strobe circuit, thus reducing the cost. In addition, it allows a user to decide when to use the strobe flash. In a oscillation charge/discharge circuit, an oscillation startup switch is installed between a battery and a transistor through the primary coil of a step-up transformer. When the switch is closed, the direct current input to the transistor is suppressed, and an abnormal input current control resister may have a low resistance value. A trigger flash circuit comprises a circuit that both controls the constant-voltage flash of a neon lamp NE and controls the oscillation stop of the transistor. A recharge circuit comprises a circuit that uses the resistor in the primary coil of the step-up transformer and a capacitor that takes out pulse fluctuations when the xenon lamp Xe is flashed.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: July 14, 1998
    Inventor: Takumi Matsuo
  • Patent number: 5747944
    Abstract: In a flash device of the kind having a coil connected to a flash lamp and arrange to bring about a flat emission by the action of the coil, a switching circuit is arranged to short-circuit the coil after flashing emission is started, so that a good flash terminating characteristic for normal flashing emission can be obtained.
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: May 5, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshihito Harada
  • Patent number: 5739643
    Abstract: An output from a D.C. power source is supplied to a flashlamp through a high speed switching circuit. A current detection circuit detects a current from the high speed switching circuit and a voltage detection circuit detects a voltage applied to the flashlamp. A multiplication circuit multiplies the detected current and voltage to compute a product value. The high speed switching circuit is controlled so that the product value becomes equal to a predetermined value or an amplitude level of a pulse shape control signal inputted from the outside.
    Type: Grant
    Filed: September 27, 1995
    Date of Patent: April 14, 1998
    Assignee: NEC Corporation
    Inventor: Takeshi Usui
  • Patent number: 5721986
    Abstract: Disclosed is a camera provided with a strobe system. The strobe system includes a capacitor to be charged. Charging voltage of the capacitor can be detected through an output terminal. The output terminal can be electrically connected and disconnected to and from the capacitor by a switching element. The circuit has an input terminal which receives a control signal. In response to the control signal, charging operation is enabled, and at the same time, the switching element is controlled to connect the output terminal to the capacitor. While, if the charging voltage has reached an upper limit, the charging operation is disabled and the output terminal is disconnected from the capacitor for a predetermined period of time by changing the status of the control signal.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: February 24, 1998
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventors: Hiroshi Nomura, Kazuyoshi Azegami, Takamitsu Sasaki, Yasushi Tabata, Norio Numako, Yoshinari Tanimura, Takuma Sato, Masaaki Kishimoto
  • Patent number: 5717962
    Abstract: A power supply circuit includes a booster circuit for boosting an output voltage from a power supply battery to predetermined positive and negative voltages, respectively. A main capacitor is charged by the predetermined positive or negative voltage boosted by the power supply circuit. In a discharge tube, a discharge current flows on the basis of the charge built up on the main capacitor, so that flash light emission is performed. A MOS controlled thyristor (MCT) is inserted in the loop of the discharge current from the main capacitor. A control circuit ON/OFF-controls the MCT by selectively applying the predetermined positive or negative voltage from the power supply circuit to the gate terminal of the MCT.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: February 10, 1998
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Toyoji Sasaki, Hiroshi Yamada
  • Patent number: 5712535
    Abstract: A fill-in light emitting apparatus having an illuminating mechanism for emitting illumination light whose color temperature can be varied; a color temperature metering mechanism for measuring the color temperature of the external light; and a color temperature controlling mechanism for varying the color temperature of the illumination light in accordance with color temperature data measured by the color temperature metering mechanism.
    Type: Grant
    Filed: October 31, 1995
    Date of Patent: January 27, 1998
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventor: Kimiaki Ogawa
  • Patent number: 5708878
    Abstract: A flash control circuit for use with a system controller is disclosed. The circuit includes a booster unit for receiving a first voltage signal and for outputting a second voltage signal to a lamp. The booster unit boosts the first voltage signal and then charges the boosted first voltage signal. Also included is a voltage sensor for sensing the voltage of the second voltage signal and for transmitting a voltage indication signal to the system controller. An oscillator outputs the first voltage signal according to an oscillation control signal from the system controller, and a triggering unit generates a trigger pulse according to a lighting control signal output from the system controller. The circuit further includes an accidental lighting prevention unit coupled to the triggering unit.
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: January 13, 1998
    Assignee: Samsung Aerospace Industries, Ltd.
    Inventor: Inh-seok Suh
  • Patent number: 5668445
    Abstract: An electronic flash apparatus having: a condenser; a flash tube which is connected with said condenser and flashes when electricity stored in the condenser is discharged; and a flash operation control device for performing drive control of said flash tube so that the flash tube flashes repeatedly when electricity stored in said condenser is applied to the flash tube.The flash operation control circuit varies the luminous amount of each of the repeated flashes of the flash tube according to the voltage accumulated in the condenser.
    Type: Grant
    Filed: October 24, 1996
    Date of Patent: September 16, 1997
    Assignee: Nikon Corporation
    Inventor: Hideki Matsui
  • Patent number: 5661372
    Abstract: A stroboscopic instrument is constructed of a gate-controlled switching element forming a discharge loop that is connected in series with a discharge lamp and main capacitor for storing charge that causes the discharge lamp to flash. The stroboscopic instrument further comprises: a stroboscopic flashing control circuit for controlling the operation of stroboscopic flashing; a low-voltage power supply that has an output voltage lower than the driving voltages of the stroboscopic flashing control circuit and the gate-controlled switching element; a first constant voltage regulator for stepping up the voltage of the low-voltage power supply up to the driving voltage of the stroboscopic flashing control circuit; and a second constant voltage regulator for stepping up the voltage of the low-voltage power supply or the output voltage of the first constant voltage regulator up to the driving voltage of the gate-controlled switching element.
    Type: Grant
    Filed: April 26, 1995
    Date of Patent: August 26, 1997
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Toshiaki Ishimaru, Hiroshi Yamada
  • Patent number: 5640070
    Abstract: In an electronic flash apparatus having a flash tube (2) which is disposed inside a reflector (3), having a storage capacitor (5) which can be discharged via the flash tube having a d.c. voltage converter (7) which is fed by a d.c. voltage source, preferably a battery (6), and by means of which the storage capacitor (5) can be recharged to its operating voltage following each discharge, and having a control circuit (8) which switches the d.c. voltage converter (7) on or off as a function of the voltage at the storage capacitor (5), overheating of the reflector (3) and/or its front elements (4) is prevented by a protective circuit (12) which influences the flash light emission in such a way that the temperature of the reflector (3) and/or its front elements (4) does not exceed a predetermined maximum value.
    Type: Grant
    Filed: September 27, 1995
    Date of Patent: June 17, 1997
    Assignee: Metz-Werke GmbH & Co. KG
    Inventor: Michael Wolf
  • Patent number: 5640620
    Abstract: With an electronic flash device that utilizes an IGBT, circuit construction can be simplified using a single condenser as both the trigger condenser of a trigger circuit and the voltage doubling condenser. In addition, because the recharging of the multi-purpose condenser is accomplished through the radiation current that flows through the light emitting tube directly after the collector/emitter gap of the IGBT becomes nonconductive, the device allows flash radiations to be repeated at high speed.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: June 17, 1997
    Assignee: Nikon Corporation
    Inventor: Hideki Matsui
  • Patent number: 5640624
    Abstract: A high-speed flash charging system for a camera accelerates flash charging time by storing electrical energy in capacitors in a first charging section when photographing is started after power is applied. When the flash is to be emitted, the system transforms the stored energy and charges a second set of capacitors to be used for powering the flash. After charge is transferred from a capacitor in the first set to the second set, the system determines whether enough charge is present in the second set to activate the flash. If there is not enough charge present, another capacitor from the first set is discharged.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: June 17, 1997
    Assignee: Samsung Aerospace Industries, Ltd.
    Inventor: Ki-Yul Lee
  • Patent number: 5634153
    Abstract: An electronic flash device includes an illumination element, an actuation circuit having a flash capacitor providing energy releasable to illuminate the element, and a self-oscillating charging circuit, having a transistor, for charging the capacitor. The invention is characterized by a resistor located between a base of the transistor and ground for preventing the self-oscillating circuit from charging the capacitor when the flash device is exposed to an external static electric charge.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: May 27, 1997
    Assignee: Eastman Kodak Company
    Inventor: Douglas W. Constable
  • Patent number: 5602446
    Abstract: A fast repetition rate (FRR) flasher suitable for high flash photolysis including kinetic chemical and biological analysis. The flasher includes a power supply, a discharge capacitor operably connected to be charged by the power supply, and a flash lamp for producing a series of flashes in response to discharge of the discharge capacitor. A triggering circuit operably connected to the flash lamp initially ionizes the flash lamp. A current switch is operably connected between the flash lamp and the discharge capacitor. The current switch has at least one insulated gate bipolar transistor for switching current that is operable to initiate a controllable discharge of the discharge capacitor through the flash lamp. Control means connected to the current switch for controlling the rate of discharge of the discharge capacitor thereby to effectively keep the flash lamp in an ionized state between Successive discharges of the discharge capacitor.
    Type: Grant
    Filed: March 23, 1995
    Date of Patent: February 11, 1997
    Assignee: Associated Universities, Inc.
    Inventors: Zbigniew Kolber, Paul Falkowski
  • Patent number: 5592257
    Abstract: An electronic flash device having a slave emission function and a standby mode, includes a setting member for setting the slave emission function, activation means activated in response to an input generated upon the function setting operation of the setting member, and power supply control means for controlling a power supply of the electronic flash device to be turned on based on the activation of the activation means.
    Type: Grant
    Filed: July 7, 1995
    Date of Patent: January 7, 1997
    Assignee: Nikon Corporation
    Inventors: Hiroshi Sakamoto, Hideki Matsui, Nobuyoshi Hagiuda
  • Patent number: 5587629
    Abstract: A transformerless high-voltage generator circuit includes an amplifier and a feedback circuit connected together to form an oscillator. Due to the configuration of the feedback circuit, a high-voltage output is obtained at an intermediate point within the feedback circuit without the use of a transformer. The resulting circuit may be used in various applications, such as an electronic photoflash unit, in order to reduce the size, weight and cost of the finished product by eliminating the need for a transformer to obtain the desired high voltage.
    Type: Grant
    Filed: August 28, 1995
    Date of Patent: December 24, 1996
    Assignee: Philips Electronics North America Corporation
    Inventor: Viktor L. Gornstein
  • Patent number: 5574337
    Abstract: An electronic flash device including a self-oscillating charging circuit, a momentary trigger for initiating oscillations of the circuit to charge a flash capacitor, and a voltage sensing device coupled directly between the circuit and the flash capacitor for arresting the oscillations when the capacitor is fully charged. The voltage sensor includes a zener diode in series with a neon ready-light, and switches on a transistor to ground the charging circuit and arrest the oscillations when the capacitor is fully charged. Actuation of the flash device automatically restarts the oscillations and recharges the flash capacitor. A process for recycling a single use camera having such an electronic flash device also is disclosed.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: November 12, 1996
    Assignee: Eastman Kodak Company
    Inventor: Clay A. Dunsmore
  • Patent number: 5570077
    Abstract: A drive circuit for use with an ambient condition detector limits heat dissipation and associated temperature rises in the presence of varying RMS values of an applied AC signal. The drive circuit includes a voltage doubler with a current regulator located between first and second storage elements. In the presence of a sensed ambient condition, which exceeds a predetermined threshold the regulator is enabled permitting one of the storage elements to be charged to a voltage on the order of twice the peak value of the applied AC voltage. A digital timer is used to trigger a flashable visual indicator from the stored DC voltage. The regulator provides a substantially constant DC voltage to the visual indicator in the presence of a varying AC line voltage.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: October 29, 1996
    Assignee: BRK Brands, Inc.
    Inventor: Michael A. Swieboda
  • Patent number: 5532555
    Abstract: An electronic flash apparatus having a main capacitor for storing charges, a discharge light emitting tube for emitting light in accordance with the charges stored in the main capacitor, a CPU for performing camera sequence control, and an IGBT coupled to each of the discharge light emitting tube and the CPU. The CPU includes a light emission control terminal for controlling a light emission timing of the discharge light emitting tube and the CPU is supplied with a CPU operation voltage. The IGBT includes a gate terminal connected to the light emission control terminal of the CPU, a collector terminal, and an emitter terminal, wherein, responsive to the light emission control terminal inputting to the gate terminal a control voltage substantially equivalent to the CPU operation voltage, a channel is formed between the collector terminal and the emitter terminal and the charges of the main capacitor are discharged through the discharge light emitting tube.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: July 2, 1996
    Assignee: Olympus Optical Co., Ltd.
    Inventor: Hiroshi Yamada
  • Patent number: 5530320
    Abstract: A device for controlling the firing of one or more electronic flash units by a leaf type camera shutter. Flash synchonization is provided by switch selectible modes at shutter opening, at shutter closing, or with a plurality of electronic flash units, at both shutter opening and shutter closing. The flash fire control system for leaf shutter cameras makes possible a wide variety of photographic lighting effects and can be incorporated in a shutter mechanism, camera body, electronic flash unit or flash remote controller or configured as a self-contained accessory device.
    Type: Grant
    Filed: July 10, 1995
    Date of Patent: June 25, 1996
    Inventor: Neal Chaves
  • Patent number: 5523654
    Abstract: This circuit facilitates the triggerability of a remote three wire flashtube and trigger coil assembly at a much lower than normal anode power supply voltage. The discharge of the trigger capacitor produces the usual trigger-event in the trigger coil. Simultaneously, a trigger boost capacitor boosts the flashtube anode voltage to approximate the supply voltage plus the voltage across the trigger coil primary winding. As a result, the flashtube anode voltage is essentially doubled at the outset of each trigger event.
    Type: Grant
    Filed: June 16, 1994
    Date of Patent: June 4, 1996
    Assignee: Tomar Electronics, Inc.
    Inventors: Thomas R. Sikora, Richard J. Garling
  • Patent number: 5498935
    Abstract: An apparatus and method for controlling the current delivered to a flash lamp is disclosed. The apparatus and method is particularly useful for controlling the current delivered to a flash lamp used in a laser and most particularly useful in connection with lasers used for medical procedures. The apparatus controls the length of the electrical pulse which is delivered to the flash lamp and also limits the current which passes through the flash lamp to that which is desired for optimized operation. A semiconductor switch electrically connects and disconnects the flash lamp from one or more capacitors for the desired length of time. The length of time can be automatically adjusted to provide the desired flash lamp output and thus the desired laser output. The switch provides substantially a square wave having a plateau voltage with very fast rise and fall times on both sides of the plateau so that a suitable square wave is formed.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: March 12, 1996
    Assignee: William H. McMahan
    Inventors: William H. McMahan, Kevin W. Gordon
  • Patent number: 5485361
    Abstract: A flyback charger for an energy-storage capacitor has a controller for causing the energy-storage pulses of current in the transformer primary winding and the energy-delivery pulses of current in the transformer secondary winding to be nearly flat-topped. The controller includes a peak-current-commanding current-mode control or a valley-current-commanding current-mode control which controls the duration of a switching circuit on and off interval, respectively, responsive to the current flowing in the transformer primary winding and secondary winding, respectively. A feed-forward controller controls the duration of the switching circuit off and on interval, respectively, in response to the voltage provided by the secondary winding and D-C supply voltage, respectively. When using the valley-current-commanding current-mode controller, there may be a fixed duration of the switching circuit on interval.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: January 16, 1996
    Inventor: Nathan O. Sokal
  • Patent number: 5461288
    Abstract: A device for controlling the surge of electrical current demanded following the discharge of a lighting system comprised of multiple electronic flash units powered from a common source. Individual electronic flash units are re-charged sequentially by the invention after system discharge, thus limiting the current demand to approximately the level produced by a single strobe light apparatus. The power management device for large electronic flash units can be integrated into the circuits of a strobe light apparatus, a generator, inverter or battery pack itself, or it can be configured as a self-contained accessory device.
    Type: Grant
    Filed: January 27, 1993
    Date of Patent: October 24, 1995
    Inventors: Neal Chaves, David Mendelsohn, Philip J. Doucet
  • Patent number: 5461286
    Abstract: To operate a low-pressure discharge lamp, typically a fluorescent lamp, from a low voltage source of, for example, between 5 and 24 V, two diodes (D1, D2) polarized to provide for current passage towards the lamp are connected between the output of a blocking oscillator and the lamp (L). At least one diode (D2) provides for preheating the lamp electrode. The other diode (D1) prevents immediate starting of the lamp; it is integrated in the circuit between the secondary winding (N2) of the blocking oscillator transformer (TR) and one lamp electrode (E1). The first diode (D2) is connected between the primary winding (N1) and the other terminal of the secondary winding (N2), and also to the other lamp electrode (E2). An additional capacitor (C4) connected, effectively, across the lamp (L) improves the starting of the lamp. The circuit is readily adaptable for association with a recharging circuit (FIG. 3) for recharging a rechargeable battery to supply the lamp.
    Type: Grant
    Filed: November 1, 1994
    Date of Patent: October 24, 1995
    Assignee: Patent-Treuhand-Gesellschaft f. elektrische Gluehlampen mbh
    Inventor: Walter Hirschmann
  • Patent number: RE35196
    Abstract: An electronic flash control device makes sure that the emission of light of an electronic flash is not impaired by a noise component signal prior to generation of a suitable quantity of light by the flash. A trigger signal is applied by the control device to allow the flash to emit light. An enable signal is supplied to a quenching circuit a predetermined time after the noise of the trigger signal has been produced. When the quantity of light from an object to be photographed by the camera reaches a certain value and the enable signal occurs, the quench circuit suppresses the emission of light by the electronic flash.
    Type: Grant
    Filed: August 10, 1994
    Date of Patent: April 2, 1996
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventors: Shigeru Iwamoto, Isamu Hashimoto
  • Patent number: RE35837
    Abstract: A flashtube circuit includes a switch which in a first position regulates the storage over time of energy in a first energy storage device and in a second position allows the transfer of energy from the first energy storage device to a second energy storage device. A microcontroller receives the input voltage and then samples and digitizes it for input into a lookup table. The microcontroller repeatedly cycles the switch between flashes by controlling the time the switch is in its first position. The lookup table output provides the signal for determining the time the switch remains in its first position. The time interval from the last flash controls the time the switch is in its second position. The cycling of the switch is controlled accordingly such that the second energy storage device acquires the predetermined amount of energy for the flash just as the triggering circuit is initiated by the microcontroller.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: July 7, 1998
    Assignee: Wheelock Inc.
    Inventors: Joseph Kosich, Edward V. Applegate