Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Minoru Ozasa

Masahiro Yamamoto

Syunsuke Ono

Go Yamada

Masaru Ikeda

Hiroji Morimoto

Shunsuke Ono

Tsuyoshi Ichibakase

Tomoyuki Seki

Takashi Tsutatani

Haruo Nagai

Masato Yoshida

Fumio Takagi

Katsumi Hirai

Akio Iwasaki

Hiroshi Imamura

Testuhiro Ueda

Masahiro Tsujikawa

A calculation processing sub-unit controls a frequency control sub-unit and a DC-AC inverter circuit to repeat a first period and a second period. The first period continues for at least two cycles, each cycle including a first sub-period during which the current is maintained in one polarity and a second sub-period during which the current is maintained in an opposite polarity. The second sub-period is shorter than and subsequent to the first sub-period. The second period, during which the current is maintained in a constant polarity, is as long as or longer than the first sub-period. The calculation processing sub-unit controls a PWM control sub-unit and a voltage step-down circuit to maintain an absolute value of the current at a first current value during at least part of the first period, and at a second current value, greater than the first current value, during the second period.

High pressure discharge lamp lighting device, projector provided with the same, and high pressure discharge lamp lighting method

A high-pressure discharge lamp lighting device that suppresses deterioration and the expansion of inter-electrode distance in a pair of electrodes within a high-pressure discharge lamp, more effectively than conventional technology. The frequency of the AC current supplied to a high-pressure discharge lamp alternates between a first frequency and a second, higher frequency, while the magnitude of the AC current alternates between a first value and a second, higher value. The suppressing effect is realized by repeatedly alternating the frequency and repeatedly alternating between a first period at the first frequency and a second period at the second frequency, with the second, higher-magnitude current being used in the latter and the first current being used in the former.

High-pressure discharge lamp light-up device, high-pressure discharge lamp apparatus using same, projector using high-pressure discharge lamp apparatus, and light-up method for high-pressure discharge lamp

Constant current control is performed after the completion of starting operation of a high-pressure mercury-vapor lampand then lighting is shifted to constant power lighting. Except during a modulation forbidden period as a certain period from the completion of the starting operation, the frequency of an alternating current is subjected to frequency modulation control for being modulated to at least a first frequency and a second frequency having higher audibility than the first frequency. During the modulation forbidden period defined as a period from the completion of the starting operation until a predetermined time before lighting is shifted to constant power lighting, from the completion of the starting operation until lighting is shifted to constant power lighting, or from the completion of the starting operation until a predetermined time after lighting has been shifted to constant power lighting, the frequency modulation control is not performed and an alternating current with a third frequency lower than the second frequency is supplied. The quietness can be increased without adversely affecting the frequency modulation control on an alternating current for properly growing and maintaining protrusions of electrodes.

High-pressure discharge lamp lighting device with current control, high-pressure discharge lamp device using same, projector using said high-pressure discharge lamp device, and high-pressure discharge lamp lighting method with current control

A first waveform (a rectangular waveform, for example) is applied as the waveform of the alternating current supplied to a high-pressure discharge lamp for a predetermined time from the beginning of lighting of the lamp and a second waveform (a staircase waveform, for example) is applied as the waveform of the alternating current after the elapse of a predetermined time (100 [s], for example). The alternating current with the first waveform has a lower absolute instantaneous value in a final section of each half-cycle period thereof than in the other sections and the alternating current with the second waveform has a higher absolute instantaneous value in a final section of each half-cycle period thereof than in the other sections.

High-pressure discharge lamp lighting device, high-pressure discharge lamp utilizing the same, projector utilizing said high-pressure discharge lamp, and high-pressure discharge lamp lighting method

The frequency of the alternating current to be supplied to the high-pressure discharge lamp is switched among a first frequency, a second frequency greater than the first frequency, and a third frequency smaller than or equal to the first frequency. In the switching, a period A, in which the alternating current of the third frequency is supplied, occurs at the beginning of each of the predetermined time intervals. A remainder of each of the predetermined time intervals includes a period B, in which the alternating current of the first frequency is supplied, and a period C, in which the alternating current of the second frequency is supplied, the periods B and C being alternately repeated, so as to control the period A to be longer than the period B and to have a length corresponding to a predetermined number of cycles, ranging from 5.5 to 50 cycles inclusive.

High-pressure discharge lamp lighting device, high pressure discharge lamp apparatus using this, projector using the high-pressure discharge lamp apparatus, and high-pressure discharge lamp lighting method

A high-pressure discharge lamp system has a high-pressure mercury lampand a lighting circuitthat operates the lamp. The lampincludes an envelope having a light emitting parthaving a first and a second electrodearranged therein and a first and a second sealing partoppositely extending from the light emitting part, and a conductorelectrically connected to the second electrode. Particularly a portion of the conductoris at least in contact with or in closest proximity to the outer surface of the first sealing partsubstantially at a single point in an area corresponding to a first metal foilconnected to the first electrode. The circuitactivates the lampby placing high-frequency voltage at a predetermined frequency within a range of 10 [kHz]-10 [MHz], inclusive, between the electrodes

High-pressure discharge lamp system and projector using the same

In a high-pressure discharge lamp that includes a bulb formed from a light emitting part having a discharge space therein and a pair of sealing parts connected to the light emitting part, and an electrode pair disposed within the discharge space, a section of a proximity conductor is wound substantially spirally around one of the sealing parts within a predetermined range from the light emitting part, while the remaining section of the proximity conductor crosses over the light emitting part and is electrically connected to the electrode nearer the other sealing part. By initiating a discharge after applying a high-frequency voltage of 1 kHz to 1 MHz to a high-pressure mercury lamp having this structure, the breakdown voltage can be suppressed to at least 8 kV.

High-pressure discharge lamp, lighting method and lighting device for high-pressure discharge lamp, high-pressure discharge lamp device, and lamp unit, image display device and headlight device

The high-pressure discharge lamp lighting device of the invention includes a lighting circuit for supplying an alternating current to a high-pressure discharge lamp to cause lighting, the high-pressure discharge lamp having an arc tube in which a halogen material is enclosed and a pair of electrodes is disposed, and each electrode having a protuberance at a tip thereof. A frequency of the alternating current varies without dependency on operating data that varies as a lighting time of the high-pressure discharge lamp elapses.

High-pressure discharge lamp lighting device

After startup, a lighting method for a high-pressure discharge lamp is to light the lamp at a rated frequency without switching the frequency for 120 seconds (S, S), and thereafter to switch from the rated frequency to a more audible frequency in accordance with a change in voltage value (Sto S).

Lighting method for a high-pressure discharge lamp, lighting circuit for a high-pressure discharge lamp, high-pressure discharge lamp apparatus, and projector-type image display apparatus

High-pressure discharge lamp lighting device with alternating current frequency time periods

Device for lighting a high-pressure discharge lamp by supplying alternating current

The present invention provides a high-pressure discharge lamp having a long life. A high-pressure discharge lamp () comprises a light emitting part (); first and second sealing parts (); first and second electrodes (); a first conductive lead () wound around the first sealing part; a first lead wire () electrically connecting the first conductive lead to the first electrode; a second conductive lead () wound around the second sealing part; and a second lead wire () connecting the second conductive lead to the first electrode. The second lead wire detours the light emitting part to avoid being affected by heat. After the lamp is turned off, the temperature of base parts of the electrodes immediately falls, and much mercury can be collected in the vicinities of the base parts.

High-pressure discharge lamp, lamp unit and image display device

Provided is a method for lighting a high pressure discharge lamp capable of increasing the life thereof. The lighting method is as follows. When the time elapse after lighting up the discharge lamp is within a predetermined condition (e.g. 5 minutes or less), constant current control is performed if the lamp voltage is lower than switching voltage (here, a first voltage value V) and constant power control is performed to maintain the lamp power at a power value Wif the lamp voltage is equal to or above the switching voltage. After the predetermined condition (5 minutes) is exceeded, the constant power control is performed by lowering the value of the switching voltage from the first voltage value Vto the second voltage value V. If the lamp voltage is equal to or above the switching voltage lowered, the lamp power is maintained at power value W

High pressure discharge lamp operation method, operation device, light source device, and projection type image display device

A lighting method for a high pressure discharge lamp in which a high-pressure pulse is applied to cause a dielectric breakdown, and then in step S, it is judged whether the lamp voltage is higher than 25 volts as the current switching voltage. If it is judged negatively in step S, the control circuit () performs a constant current control with the current limiting level set to 6 amperes (step S). If it is judged that the lamp voltage is higher than 25 in step S, the control circuit () performs a constant current control with the current limiting level set to 4 amperes (step S). When the lamp voltage rises and reaches 50 volts, the control circuit () performs a constant power control so that the lamp power remains to be 200 W.

Growing community of inventors

Kyoto, Japan

Minoru Ozasa