专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明专利

JPH01129690A CHARACTER ADDER CIRCUIT WITH BACKGROUND 失效
公开(公告)号：JPH01129690A
公开(公告)日：1989-05-22
申请号：JP28734487
申请日：1987-11-16
申请人： HITACHI LTD , HITACHI VIDEO ENG
发明人： NARITA HIROSHI
IPC分类号： H04N9/00 , H04N5/278 , H04N9/74
摘要： PURPOSE:To obtain ease to see display by emphasizing only a burst signal in a burst signal and a color signal constituting the color signal of background so as to constitute the color signal thereby reducing the coloring caused to the character part. CONSTITUTION:An output (a) of an fSC oscillation circuit 1 is frequency-divided by a frequency divider circuit 2 and given to a burst gate generating circuit 3 to generate a burst signal (b). The burst signal (b) is emphasized by a burst emphasis circuit 7 and added to a color signal (c) by an adder 9. A synchronizing signal (f) is added to an output signal (e) of the adder 9 and its output is given to a switching circuit 11 controlled by an output (g) of a character signal generating circuit 8 and a character signal (h) with background is obtained.

2. 发明专利

JPH02101887A MAGNETIC RECORDING AND REPRODUCING DEVICE 失效
公开(公告)号：JPH02101887A
公开(公告)日：1990-04-13
申请号：JP25378588
申请日：1988-10-11
申请人： HITACHI LTD , HITACHI VIDEO ENG
发明人： TAGASHIRA TERUHIKO , NARITA HIROSHI
IPC分类号： H04N5/278 , H04N9/79
摘要： PURPOSE:To attain character display on a screen even in a TV set without any RGB input terminal by synthesizing an RGB signal onto a video signal or a noise signal with synchronizing signal. CONSTITUTION:The RGB signal outputted from a character generating circuit 1 with RGB output is inputted to a TV set 2 with RGB input terminal. Thus, a character is displayed in color on the TV 2. Then in the case of a TV without any RGB input terminal, the RGB signal, a blanking signal and a video signal are inputted to an RGB signal synthesis circuit 5 and an the synthesis output signal is inputted to an RF converter 6, in which the signal is RF-modulated and outputted, then the resulting signal is received by the TV 3 without any RGB input terminal and displayed as a character.

3. 发明专利

JPH04207372A TELEVISION RECEIVER 失效
公开(公告)号：JPH04207372A
公开(公告)日：1992-07-29
申请号：JP32883390
申请日：1990-11-30
申请人： HITACHI LTD , HITACHI VIDEO ENG
发明人： NARITA HIROSHI
IPC分类号： H04N5/60
摘要： PURPOSE:To contract the size of a circuit and to prevent the generation of erroneous display in the reception of a SAP(second audio program) signal by controlling an SAP signal squelch circuit in accordance with the decided output of a synchronizing detection circuit for deciding received field intensity from the synchronizing signal level of a received video signal. CONSTITUTION:An SAP signal to be the 2nd voice signal is frequency- multiplexed with the 1st voice signal, the multiplexed signal is broadcasted and a synchronism detection circuit 9 discriminate whether the broadcasted signal is in an effective receiving state, a defective receiving state, or a receiving signal absent state. In the effective receiving state, when the SAP squelch circuit 4 is controlled in accordance with the decided result of the circuit 9, the circuit 4 is in a non-driven state and a display means 7 displays the reception of the SAP signal. In the defective receiving state or in the receiving signal absent state, the circuit 4 is driven and the means 7 is not driven. Consequently, the generation of erroneous display in the receiving state of the SAP signal can be prevented and the circuit size can be contracted.

4. 发明专利

JPH02105381A MAGNETIC RECORDING/REPRODUCING DEVICE CONTAINING FAN MOTOR 失效
公开(公告)号：JPH02105381A
公开(公告)日：1990-04-17
申请号：JP25714588
申请日：1988-10-14
申请人： HITACHI LTD , HITACHI VIDEO ENG
发明人： NARITA HIROSHI , TAGASHIRA TERUHIKO
IPC分类号： G11B33/14
摘要： PURPOSE:To prevent the rise of an internal temperature and at the same time to reduce the noise level in a stop state for a magnetic recording/reproducing device by driving a fan motor only when a capstan motor or a cylinder motor is driven. CONSTITUTION:The output of a cylinder motor start control circuit 3 and the output of a capstan motor start control circuit 6 undergo the diode OR and are supplied to a fan motor drive circuit 8 as a control signal. In other words, a fan motor 7 works only when a cylinder motor 1 or a capstan motor 4 is working. In this case, the power consumption of a magnetic recording/ reproducing device 9 is increased together with the rise of the internal temperature. Thus the motor 7 is driven for the decrease of the internal temperature. Furthermore the motor 7 does not work in a stop state of the device 9 and therefore the noise level is reduced in the stop state.

5. 发明专利

JPH10112983A PROTECTING APPARATUS FOR POWER CONVERTER 失效
公开(公告)号：JPH10112983A
公开(公告)日：1998-04-28
申请号：JP26695896
申请日：1996-10-08
申请人： HITACHI LTD
发明人： NARITA HIROSHI
IPC分类号： H02H3/08 , H02M1/06 , H02M7/12 , H02M7/155 , H02M7/48 , H02M7/515
摘要： PROBLEM TO BE SOLVED: To quicken connection to a discharging resistor in an failure of an apparatus for regenerating snubber-circuit-stored energy to a power source, by separating the means for regenerating the snubber-circuit-stored energy to the power source by a fuse, and connecting a discharging resistor for the snubber-circuit-stored energy through a breakover device. SOLUTION: If a snubber regenerative chopper CH has a conduction trouble by some cause, in the cource of on/off controlling the GTO thyristors G of a chopper, first of all, a fuse F is fused to separate the snubber regenerative chopper CH. As the result, stored energy in an anode reactor LA increase the voltage of a storage capacitor CLA. Next, a breakover device BO breaks over and becomes in a conducting state, and a discharging resistor RLA is connected in parallel with the storage capacitor CLA. Consequently, the stored energy of the anode reactor LA is consumed by the discharging resistor RLA through the medium of the storage capacitor CLA.

6. 发明专利

JPH08331858A SEMICONDUCTOR POWER CONVERTING APPARATUS 失效
公开(公告)号：JPH08331858A
公开(公告)日：1996-12-13
申请号：JP13140995
申请日：1995-05-30
申请人： HITACHI LTD
发明人： SAKAI HIROMITSU , EGUCHI YOSHIO , KOSEKI SHOICHIRO , NARITA HIROSHI , IYOTANI RYUJI
IPC分类号： H02M7/48 , H02M7/515
摘要： PURPOSE: To improve insulation performance by reducing the loss of DC power to be applied to a self-extinguishing function element mainly only while the operation of the semiconductor power converting apparatus is stopped without use of an external signal. CONSTITUTION: During stop of operation of the apparatus, a semiconductor switching element 4 is ignited with a switching circuit 51 by sensing a voltage of a self-extinguishing function element 1, a DC voltage of the self-extinguishing function element 1 is applied to a resistor 3 and a charging current flows into a capacitor 6. Charges in the capacitor 6 supply a power to a gate drive circuit 8 and output a gate inverse bias to the self-extinguishing function element 1 during stop of operation of the apparatus. When the apparatus starts operation, the self-extinguishing function element 1 is ignited, the capacitor 6 discharges in such a form as applying an inverse voltage to the semiconductor switching element 4 and thereby the semiconductor switching element 4 is extinguished. As a result, a resistor 3 can be separated during operation of the semiconductor power converting apparatus without use of external signal.

7. 发明专利

JP2534704B2 失效
公开(公告)号：JP2534704B2
公开(公告)日：1996-09-18
申请号：JP11075187
申请日：1987-05-08
申请人： HITACHI LTD
发明人： NARITA HIROSHI , KUROTAKI YOSHIMI , NAKAMURA KYOSHI
IPC分类号： H02M1/088 , H03K17/10 , H03K17/16 , H03K17/64

8. 发明专利

JPH08154374A PROTECTION DEVICE OF POWER CONVERSION APPARATUS 失效
公开(公告)号：JPH08154374A
公开(公告)日：1996-06-11
申请号：JP31577494
申请日：1994-11-25
申请人： HITACHI LTD
发明人： NARITA HIROSHI , ONDA KENICHI , MOTOBE MITSUSACHI
IPC分类号： H02M1/00 , H02M7/12 , H02M7/155 , H02M7/515
摘要： PURPOSE: To obtain a protection device which can protect an over-current without making a fuse capacity large by a method wherein a reactor, for overcurrent suppression, to which a diode has been connected in parallel or a fuse is connected in series with a filter capacitor. CONSTITUTION: Normally, a difference current between a supply current on the side of a converter and a load current for an inverter flows to a filter capacitor (CF). Out of the difference current which flows to the CF, a charging current flows to a diode (DFU), and a discharge current flows to a reactor (LCF) for overcurrent suppression. In addition, in an ordinary operation, the charging current flows from the side of the converter, and the charging current flows to the side of the inverter. Normally, the load current flows via the LCF by removing a ripple portion by means of the current smoothing action of the LCF and the DFU. Then, when a phase short circuit is generated, an overcurrent in a discharge direction flows through the LCF from the CF. Then, the value of the LFU is set in such a way that a current flowing to a GTO thyristor in the phase short circuit becomes a surge-current withstand or lower. Thereby, it is possible to prevent the damage to the GTO thyristor due to the overcurrent in the phase short circuit.

9. 发明专利

JPH0678524A LOW-LOSS SNUBBER CIRCUIT FOR POWER CONVERTER 失效
公开(公告)号：JPH0678524A
公开(公告)日：1994-03-18
申请号：JP22832592
申请日：1992-08-27
申请人： HITACHI LTD
发明人： NARITA HIROSHI
IPC分类号： H02H7/12 , H02M1/06
摘要： PURPOSE:To reduce the resistance loss of a snubber circuit by connecting the anode of a snubber diode to the anode of a GTO connected in series and connecting a snubber capacitor between the anode and cathode of the snubber diode. CONSTITUTION:The voltage of the half of supply voltage is charged to snubber capacitors CSp1 and CSp2 under the state, in which an upper arm GTOp1 and a GTOp2 are turned off. When the upper arm GTOp1 and GTOp2 are tuned on the charging charges of the snubber capacitors CS, and CS are discharged by the closed circuit of formula I, and charged in a capacitor CRp for a regenerative circuit by assistance of an anode reactor LAp. When the upper arm GTOp1 and GTOp2 are turned off from an on state, the stored energy of the anode reactor LAp is discharged by the closed circuit of formula II, and charged in the capacitor CRp for the regenerative circuit. The energy of the capacitor CRp for the regenerative circuit is regenerated by a filter capacitor on the power supply side through a known DC-DC converter CONp.

10. 发明专利

JPH0334318B2 失效
公开(公告)号：JPH0334318B2
公开(公告)日：1991-05-22
申请号：JP20509581
申请日：1981-12-21
申请人： HITACHI LTD
发明人： OKAMATSU SHIGETOSHI , JINBO YOSHIJI , TSUBOI TAKASHI , NARITA HIROSHI , SUZUKI MASAHITO
IPC分类号： H02P27/06

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式