Patents by Inventor Tetsuo Terashima

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

  • Patent number: 10295893
    Abstract: A discharge lamp driving device includes a discharge lamp driving section configured to supply a driving current to a discharge lamp, a control section configured to control the discharge lamp driving section, and a voltage detecting section configured to detect an inter-electrode voltage. The control section supplies a driving current including a first alternating current when the inter-electrode voltage is equal to or higher than a first voltage, supplies a driving current including a second alternating current having a frequency which is lower than a frequency of the first alternating current when the inter-electrode voltage is lower than the first voltage and equal to or higher than a second voltage lower than the first voltage, and supplies a driving current including a third alternating current having a frequency which is higher than the frequency of the first alternating current when the inter-electrode voltage is lower than the second voltage.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: May 21, 2019
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Tetsuo Terashima
  • Patent number: 10237521
    Abstract: According to an aspect of the invention, a discharge lamp driving device includes a discharge lamp driving section, a control section, and a voltage detecting section. The control section is configured to execute a first discharge lamp driving for executing a first control and a second control for supplying a driving current including a direct current and an alternating current to a discharge lamp. In the first discharge lamp driving, the control section executes the first control when the interelectrode voltage is equal to or smaller than a first threshold voltage at predetermined setting timing and executes the second control when the interelectrode voltage is larger than the first threshold voltage at the predetermined setting timing. A rate of the direct current in the second control is larger than a rate of the direct current in the first control.
    Type: Grant
    Filed: March 3, 2016
    Date of Patent: March 19, 2019
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Shun Sato, Tetsuo Terashima, Yoichi Nakagomi
  • Patent number: 9897902
    Abstract: A discharge lamp driving device includes a discharge lamp driving section configured to supply a driving current to a discharge lamp including a first electrode and a second electrode and a control section configured to control the discharge lamp driving section. The control section is configured to repeat a unit period. The unit period includes a direct current period including a first direct current period in which a direct current having a first polarity is supplied to the discharge lamp and a second direct current period in which a direct current having a second polarity is supplied to the discharge lamp, and an alternating current period provided between the first direct current period and the second direct current period, an alternating current being supplied to the discharge lamp in the alternating current period. The control section is configured to temporally change length of the direct current period.
    Type: Grant
    Filed: January 17, 2017
    Date of Patent: February 20, 2018
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Tetsuo Terashima
  • Publication number: 20170277032
    Abstract: A discharge lamp driving device includes a discharge lamp driving section configured to supply a driving current to a discharge lamp, a control section configured to control the discharge lamp driving section, and a voltage detecting section configured to detect an inter-electrode voltage. The control section supplies a driving current including a first alternating current when the inter-electrode voltage is equal to or higher than a first voltage, supplies a driving current including a second alternating current having a frequency which is lower than a frequency of the first alternating current when the inter-electrode voltage is lower than the first voltage and equal to or higher than a second voltage lower than the first voltage, and supplies a driving current including a third alternating current having a frequency which is higher than the frequency of the first alternating current when the inter-electrode voltage is lower than the second voltage.
    Type: Application
    Filed: March 2, 2017
    Publication date: September 28, 2017
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Tetsuo TERASHIMA
  • Publication number: 20170227840
    Abstract: A discharge lamp driving device includes a discharge lamp driving section configured to supply a driving current to a discharge lamp including a first electrode and a second electrode and a control section configured to control the discharge lamp driving section. The control section is configured to repeat a unit period. The unit period includes a direct current period including a first direct current period in which a direct current having a first polarity is supplied to the discharge lamp and a second direct current period in which a direct current having a second polarity is supplied to the discharge lamp, and an alternating current period provided between the first direct current period and the second direct current period, an alternating current being supplied to the discharge lamp in the alternating current period. The control section is configured to temporally change length of the direct current period.
    Type: Application
    Filed: January 17, 2017
    Publication date: August 10, 2017
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Tetsuo TERASHIMA
  • Patent number: 9709881
    Abstract: A discharge lamp lighting device according to an aspect of the invention includes a resonance circuit unit connected to a discharge lamp, a power converting unit configured to convert direct-current power into alternating-current power and supply the alternating-current power to the discharge lamp via the resonance circuit unit, and a control unit configured to supply the alternating-current power having a first frequency for causing resonance of the resonance circuit unit and a second frequency different from the first frequency, to the discharge lamp in a lighting start period from a start of lighting of the discharge lamp to a steady lighting state of the discharge. The second frequency is equal to or higher than 100 kHz.
    Type: Grant
    Filed: October 10, 2014
    Date of Patent: July 18, 2017
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tetsuo Terashima, Osamu Saito, Takeshi Nakajima
  • Patent number: 9602791
    Abstract: A discharge lamp driving device includes a discharge lamp driving unit configured to supply driving current to a discharge lamp provided with a first electrode and a second electrode, and a controller configured to control the discharge lamp driving unit. The driving current includes a first AC period and a second AC period in which an AC current is supplied. The first AC period includes a plurality of consecutive first unit driving periods each of which is formed of a first polarity period and a second polarity period, a length of the first polarity period being larger than a length of the second polarity period. The second AC period includes a plurality of consecutive second unit driving periods each of which is formed of the first polarity period and the second polarity period, the length of the second polarity period being larger than the length of the first polarity period.
    Type: Grant
    Filed: February 17, 2016
    Date of Patent: March 21, 2017
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tetsuo Terashima, Yoichi Nakagomi
  • Publication number: 20170076645
    Abstract: In an aspect of a discharge lamp driving device, the controller is configured to supply a driving current to a discharge lamp, the driving current alternately having a first period and a second period. The first period includes a plurality of consecutive first unit driving periods each of which is constituted of a first polarity period and a second polarity period. The second period includes a plurality of consecutive second unit driving periods. In the first unit driving period, a length of one polarity period is larger than the other polarity period, and a duration ratio which is a ratio of the length of the one polarity period to the length of the other polarity period is equal to or more than a predetermined value. In the second unit driving period, the duration ratio is equal to or more than 1, and is less than the predetermined value.
    Type: Application
    Filed: September 1, 2016
    Publication date: March 16, 2017
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tetsuo TERASHIMA, Yoichi NAKAGOMI
  • Patent number: 9563111
    Abstract: A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp having electrodes; a storage unit which stores information with respect to the discharge lamp; and a control unit which controls the discharge lamp driving unit, wherein the control unit is configured to execute a stationary lighting driving in which first drive power is supplied to the discharge lamp and a high-power driving in which second drive power that is higher than the first drive power is supplied to the discharge lamp, and the control unit sets first execution information of the high-power driving on the basis of first information with respect to the high-power driving stored in the storage unit, at a predetermining setting timing, and controls the discharge lamp driving unit according to the first execution information.
    Type: Grant
    Filed: October 6, 2014
    Date of Patent: February 7, 2017
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Yoichi Nakagomi, Junichi Suzuki, Tetsuo Terashima
  • Patent number: 9509965
    Abstract: A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp; and a control unit which controls the discharge lamp driving unit. The control unit is configured to execute a first driving in which first drive power is supplied to the discharge lamp and a second driving in which second drive power that is equal to or higher than the first drive power and equal to or lower than rated power of the discharge lamp is supplied to the discharge lamp. The control unit executes the second driving in a launching period of the discharge lamp, and adjusts a heat load applied to the discharge lamp in the second driving executed in the launching period, according to a degree of deterioration of the discharge lamp.
    Type: Grant
    Filed: October 3, 2014
    Date of Patent: November 29, 2016
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Yoichi Nakagomi, Junichi Suzuki, Tetsuo Terashima
  • Publication number: 20160270197
    Abstract: According to an aspect of the invention, a discharge lamp driving device includes a discharge lamp driving section, a control section, and a voltage detecting section. The control section is configured to execute a first discharge lamp driving for executing a first control and a second control for supplying a driving current including a direct current and an alternating current to a discharge lamp. In the first discharge lamp driving, the control section executes the first control when the interelectrode voltage is equal to or smaller than a first threshold voltage at predetermined setting timing and executes the second control when the interelectrode voltage is larger than the first threshold voltage at the predetermined setting timing. A rate of the direct current in the second control is larger than a rate of the direct current in the first control.
    Type: Application
    Filed: March 3, 2016
    Publication date: September 15, 2016
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Shun SATO, Tetsuo TERASHIMA, Yoichi NAKAGOMI
  • Patent number: 9439274
    Abstract: A discharge lamp driving device according to an aspect includes: a discharge lamp driving section configured to supply driving power to a discharge lamp including electrodes and a control section configured to control the discharge lamp driving section. The control section is configured to perform a steady lighting driving for supplying first driving power to the discharge lamp and a high power driving for supplying second driving power larger than the first driving power to the discharge lamp. The magnitude of heat load on the electrodes by the high power driving changes on the basis of the first driving power.
    Type: Grant
    Filed: July 9, 2015
    Date of Patent: September 6, 2016
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Yoichi Nakagomi, Tetsuo Terashima
  • Publication number: 20160249440
    Abstract: A discharge lamp driving device includes a discharge lamp driving unit configured to supply driving current to a discharge lamp provided with a first electrode and a second electrode, and a controller configured to control the discharge lamp driving unit. The driving current includes a first AC period and a second AC period in which an AC current is supplied. The first AC period includes a plurality of consecutive first unit driving periods each of which is formed of a first polarity period and a second polarity period, a length of the first polarity period being larger than a length of the second polarity period. The second AC period includes a plurality of consecutive second unit driving periods each of which is formed of the first polarity period and the second polarity period, the length of the second polarity period being larger than the length of the first polarity period.
    Type: Application
    Filed: February 17, 2016
    Publication date: August 25, 2016
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tetsuo TERASHIMA, Yoichi NAKAGOMI
  • Patent number: 9405179
    Abstract: A projector that outputs a first picture and a second picture alternately, wherein a control section performs first control and second control, controls a discharge lamp driving section. In the first control and the second control, the absolute value of a drive current is relatively small in a first period and relatively large in a second period. In the first control, the energy provided to a first electrode in the second period is greater than the energy provided to the second electrode in the second period. In the second control, the energy provided to the second electrode in the second period is greater than the energy provided to the first electrode in the second period.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: August 2, 2016
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Tetsuo Terashima
  • Patent number: 9395610
    Abstract: A light source includes a discharge lamp that outputs light, a discharge lamp driver that supplies drive power to the discharge lamp, a cooling unit that cools the discharge lamp, and a control unit that controls the cooling unit, and the control unit controls the cooling unit based on control information representing a relationship a rotation speed of the cooling unit between at least one of temperature information of the discharge lamp and a voltage between electrodes of the discharge lamp.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: July 19, 2016
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Junichi Suzuki, Yasuhiro Toba, Tetsuo Terashima
  • Patent number: 9354497
    Abstract: A projector that outputs a first image and a second image alternately, includes: a discharge lamp driving section that supplies, to a discharge lamp, a drive current that drives the discharge lamp; a state detecting section that detects a deteriorating state of the discharge lamp; and a control section that controls the discharge lamp driving section, wherein the control section controls the discharge lamp driving section so that the absolute value of the drive current becomes relatively small in the first period and relatively large in the second period and, in the second period, the control section controls the discharge lamp driving section so that the discharge lamp driving section supplies an alternating current to the discharge lamp as the drive current and controls the discharge lamp driving section so that at least part of the frequency of the drive current is decreased with the progress of the deteriorating state.
    Type: Grant
    Filed: June 4, 2014
    Date of Patent: May 31, 2016
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tetsuo Terashima, Shun Sato
  • Patent number: 9288884
    Abstract: A discharge lamp lighting method for controlling lighting of a discharge lamp includes varying an amount of generation (current value) of overshoot and undershoot generated in a waveform of a drive current that is applied when driving the discharge lamp, according to a magnitude of drive power supplied to the discharge lamp and a drive mode.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: March 15, 2016
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Yoichi Nakagomi, Tetsuo Terashima
  • Publication number: 20160066399
    Abstract: A discharge lamp driving device according to an aspect includes: a discharge lamp driving section configured to supply driving power to a discharge lamp including electrodes and a control section configured to control the discharge lamp driving section. The control section is configured to perform a steady lighting driving for supplying first driving power to the discharge lamp and a high power driving for supplying second driving power larger than the first driving power to the discharge lamp. The magnitude of heat load on the electrodes by the high power driving changes on the basis of the first driving power.
    Type: Application
    Filed: July 9, 2015
    Publication date: March 3, 2016
    Inventors: Yoichi NAKAGOMI, Tetsuo TERASHIMA
  • Patent number: 9176369
    Abstract: A projector includes a discharge lamp, a discharge-lamp driving unit, a control unit, a light modulating element, and a projection optical system. The control unit alternately repeats a high luminance period in which a driving current having a relatively large absolute value is supplied to the discharge lamp and a low luminance period in which the driving current having a relatively small absolute value is supplied to the discharge lamp. The control unit controls the discharge-lamp driving unit according to a driving current waveform formed by the control waveform unit including a direct-current waveform pattern in which the driving current in a first high luminance period, the driving current in a first low luminance period immediately after the first high luminance period, and the driving current in a second high luminance period immediately after the first low luminance period have the same first polarity.
    Type: Grant
    Filed: December 3, 2013
    Date of Patent: November 3, 2015
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tetsuo Terashima, Shun Sato
  • Patent number: 9152027
    Abstract: A control section relatively decreases an absolute value of a current supplied to a discharge lamp in a first period and relatively increases the absolute value in a second period, and in the second period, performs any one of a first control for supplying an alternating current to the discharge lamp, a second control for supplying, to the discharge lamp, a current in which a maximum duration of a first polarity is longer than that in the first control, and a third control for supplying, to the discharge lamp, a current in which a maximum duration of a second polarity is longer than that in the first control, and as the state of deterioration proceeds, decreases at least one of the maximum duration of the first polarity in the second control and the maximum duration of the second polarity in the third control.
    Type: Grant
    Filed: August 3, 2012
    Date of Patent: October 6, 2015
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tetsuo Terashima, Shun Sato