Source: http://www.google.com/patents/US6472650?dq=7650331
Timestamp: 2017-06-25 10:43:47
Document Index: 460386327

Matched Legal Cases: ['art 242', 'art 242', 'art 241', 'art 242', 'art 241', 'art 243', 'art 241', 'art 243', 'art 244', 'art 241']

Patent US6472650 - Food amount detector of a microwave oven, a microwave oven employing a food ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsA food amount detector for automatically detecting the amount of a food placed in a cooking chamber of a microwave oven, a microwave oven employing the food amount detector, and control method thereof. Output voltage of a microwave generator is detected while the microwave oven is driven, and the amount...http://www.google.com/patents/US6472650?utm_source=gb-gplus-sharePatent US6472650 - Food amount detector of a microwave oven, a microwave oven employing a food amount detector and a control method thereofAdvanced Patent SearchTry the new Google Patents, with machine-classified Google Scholar results, and Japanese and South Korean patents.Publication numberUS6472650 B2Publication typeGrantApplication numberUS 10/067,801Publication dateOct 29, 2002Filing dateFeb 8, 2002Priority dateMar 24, 1998Fee statusLapsedAlso published asCN1130110C, CN1203280C, CN1229896A, CN1501028A, DE19900321A1, DE19900321B4, US6215112, US6348680, US20010020617, US20020070213Publication number067801, 10067801, US 6472650 B2, US 6472650B2, US-B2-6472650, US6472650 B2, US6472650B2InventorsChul Kim, Tae-soo Park, Kwang-Seok Kang, Won-woo LeeOriginal AssigneeSamsung Electronics Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (17), Referenced by (7), Classifications (16), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetFood amount detector of a microwave oven, a microwave oven employing a food amount detector and a control method thereof
US 6472650 B2Abstract
A food amount detector for automatically detecting the amount of a food placed in a cooking chamber of a microwave oven, a microwave oven employing the food amount detector, and control method thereof. Output voltage of a microwave generator is detected while the microwave oven is driven, and the amount of the food placed in the cooking chamber of the microwave oven is determined based on the output voltage such detected. In accordance with the amount of the food such determined, the food is cooked under the appropriate driving conditions of the microwave oven. Accordingly, the user does not need to determine the amount of the food by himself, or set the driving conditions of the microwave oven such as cooking time, level of microwave energy, etc. As a result, the user finds it convenient when using this microwave oven, and the food is cooked under the exact driving conditions set by the microwave oven. Further, since the price of the parts are inexpensive, the manufacturing cost is reduced, and manufacturing process is simplified, so that productivity is improved.
Accordingly, the present invention has been made to overcome the above-mentioned problem of the prior art, and the first object of the present invention is to provide a food amount detector for a microwave oven capable of automatically determining the amount of the food, and microwave oven employing such a food amount detector and control method thereof.
The above object and advantages will be more apparent by describing the preferred embodiment in greater detail with reference to the accompanied drawings, in which;
FIG. 3 is a block diagram for showing the microwave oven employing the food amount detector according to the preferred embodiment of the present invention, and FIG. 4 is a circuit diagram for showing the main section of FIG. 3. In FIG. 3, reference numeral 100 is a noise filter, 110 is a driving section, 120 is a microwave generator, 130 is a voltage detector, 140 is a control section, 150 is an input section, and 160 designates a display section. A driving section 110 supplies the driving power to a high voltage transformer HVT. The high voltage transformer HVT transforms the supplied voltage 220V/110V into high voltage (approx. 2000V), and transmits the high voltage to a microwave generator 120. The microwave generator 120 is driven by high voltage supplied from the high voltage transformer HVT to generate the microwave of a predetermined frequency. A voltage detector 130 detects the voltage which is varying when the microwave generator 120 is driven. A microcomputer preferably serves as the control section 140. The control section 140 determines the amount of the food in a cooking chamber 2 by the inputted voltage of the microwave generator 120 which was detected by the voltage detector 130. Based on the amount of the food such detected as above, the control section 140 controls the driving conditions of the driving section 110, so that the microwave oven is driven in accordance with the proper cooking time, level of microwave, etc. The input section 150 inputs the data from the-function keys which were selected by the user to the control section 140, and the display section 160 inputs the display signals from the control section 140 so as to display the driving conditions of the microwave oven. The noise filter 100 receives the AC and applies the AC to the driving section 110 after eliminating the noise factor of the AC. The noise filter 100 also prevents the feed back of high-frequency wave which is generated from the microwave generator 120.
First, the user places the food to be cooked in the cooking chamber, closes the door, and pushes the start key of the input section 250 to operate the microwave oven without setting the data about the amount of the food. The input section 250 inputs the signal from the selected keys to the control section 240, and the control section 240 detects such signals and drives the driving section 210, accordingly. The driving power is supplied to the high voltage transformer HVT in accordance with the operation of the driving section 210, and the high voltage transformer HVT transforms the supplied voltage to high voltage approximately of 2000V, and transmits the high voltage to the microwave generator 220. Then the high voltage condenser HVC and the high voltage diode HVD of the microwave generator 220 double the high voltage 2000V—which is transformed by the high voltage transformer HVT—to 4000V, approximately. The magnetron MGT is driven by such doubled high voltage to generate the microwave of 2,450 MHz. In such a situation, the output voltage Vap of the cathode of the magnetron MGT is inputted to the voltage dividing resistors R10 and R11 of the voltage detector 230, and divided based on the respective resistance ratios. The divided output voltage Vb is transmitted to the control section 240. Further, the output voltage Va is transmitted to the control section 240 from the step-down voltage resistor R12, which is connected to the ground of the high voltage transformer HVT. Then, the calculation part 242 of the control section 240 calculates the impedance Rm and the cutoff voltage Ez through the values of the respective resistors R10, R11, and R12, and the voltages Va, Vb, and Vc, which were detected by the voltage detector 230. Describing such a calculation process in greater detail, the output voltages Va and Vb are defined as the following equations (1) and (2) by Ohms law.
Va=i m ×R 12 [Equation 1]
Vb=(R 11/(R 11 +R 10))×Vap [Equation 2]
Here, im is the current induced in the secondary coil of the high voltage condenser HVC, R10, R11, and R12 are respective resistors, and Va, Vb, and Vap are output voltages respectively corresponding to the resistors. Meanwhile, the output voltage Vap is defined by the following equation (3) according to a voltage balance equation.
Vap=Ez+i m ×Rm [Equation 3]
Here, Vap and im are the values of the Equations 1 and 2, Rm refers to the impedance, and Ez refers to the cutoff voltage. Accordingly, the following equation (4) is achieved by substituting Vap and im defined by the equation (3) for the equations (1) and (2) and taking the derivative with respect to a time variable (t).
Rm/R 12×( dVa/dt)=(R 10 +R 11)/R 11×( dVb/dt) [Equation 4]
Then the impedance Rm and the cutoff voltage Ez are finally calculated by the following equations (5) and (6)
Rm=R 12(R 10+R 11)/R 11×ΔVb/ΔVa [Equation 5]
Ez=(R 10+R 11)/R 11×Vb−Rm/R 12 ×Va [Equation 6]
Therefore, the calculation part 242 calculates the impedance Rm and the cutoff voltage Ez by substituting the output voltages Va, Vb, and Vap detected by the voltage detector 230, and the values of the resistors R10, R11, and R12 to the equations 5 and 6. Then, the comparison/determination part 241 compares/determines the calculated impedance Rm and the cutoff voltage Ez calculated by the calculation part 242 with the data about the impedance Rm and the cutoff voltage Ez which were pre-inputted thereto (see FIG. 11), and determines the amount of the food through the comparison result. More specifically, when the food of unidentified amount is placed in the cooking chamber, and when the impedance Rm and the cutoff voltage Ez are determined to be 300Ω and 3500V, respectively, it is determined that the amount of the food is 900 cc by the comparison/determination part 241 based on the pre-stored data shown in FIG. 11. Accordingly, the amount of the food is determined, and the driving control part 243 controls the driving section 210 based on the amount of the food which was determined by the comparison/determination part 241. That is, the driving control part 243 selectively turns on/off the relay RY1 of the driving section 210 in accordance with the amount of the food for a predetermined time, so that the food is cooked under the appropriate conditions. Further, the display control part 244 controls the display section 260 in accordance with the amount of the food, which was determined by the comparison/determination part 241, so that the data about the amount of the food are displayed on the display section 260. Accordingly, the amount of the food can be automatically detected by the microwave oven, and the food can be cooked under the appropriate conditions for the amount thereof, so that the user finds it convenient using the microwave oven and the mistakes of the user in handling the microwave oven can be prevented. Further, using parts of reasonable prices, the manufacturing cost is reduced, and the manufacturing process is more simplified, so that productivity is improved.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4009359Nov 7, 1975Feb 22, 1977Chemetron CorporationMethod and apparatus for controlling microwave ovensUS4317977Sep 6, 1979Mar 2, 1982Litton Systems, Inc.Power controlled microwave ovenUS4447693Oct 22, 1981May 8, 1984Litton Systems, Inc.Power controlled microwave ovenUS4673800Mar 6, 1986Jun 16, 1987Matsushita Electric Industrial Co. Ltd.Cooking apparatus with weighing deviceUS4900989May 2, 1988Feb 13, 1990Matsushita Electric Industrial Co., Ltd.Magnetron feeding apparatus and method of controlling the sameUS4903183Oct 17, 1988Feb 20, 1990Hitachi, Ltd.Power supply for a magnetronUS5283410Dec 18, 1991Feb 1, 1994Goldstar Co., Ltd.Method and apparatus for automatic cooking in a microwave ovenUS5382775 *Dec 27, 1991Jan 17, 1995Goldstar Co., Ltd.Method and apparatus for automatic cooking in a microwave ovenUS5506390Dec 30, 1994Apr 9, 1996Goldstar Co., Ltd.Thawing control apparatus and method for a microwave ovenUS5545880 *Mar 20, 1995Aug 13, 1996Goldstar Co., Ltd.Method for automatic control of a microwave ovenUS6268597Jan 11, 2000Jul 31, 2001Samsung Electronics Co., Ltd.Microwave ovenEP0526297A1Jul 15, 1992Feb 3, 1993Lg Electronics Inc.Automatic cooking apparatus and method for microwave ovenGB2117925A Title not availableJPH0835666A Title not availableJPH03238786A Title not availableJPS6465794A Title not availableJPS63281389A Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6867402Apr 8, 2004Mar 15, 2005Maytag CorporationSystem for sensing the presence of a load in an oven cavity of a microwave cooking applianceUS6867403 *Mar 27, 2003Mar 15, 2005Samsung Electronics Co., Ltd.Apparatus and method for automatic cookingUS7882734Oct 31, 2007Feb 8, 2011Whirlpool CorporationUtilizing motor current variations to control mixer operationUS8011825Oct 31, 2007Sep 6, 2011Whrilpool CorporationSmoothing motor speed during mixingUS20040104224 *Mar 27, 2003Jun 3, 2004Samsung Electronics Co., Ltd.Apparatus and method for automatic cookingUS20090109792 *Oct 31, 2007Apr 30, 2009Whirlpool CorporationSmoothing motor speed during mixingUS20090110788 *Oct 31, 2007Apr 30, 2009Whirlpool CorporationUtilizing motor current variations to control mixer operation* Cited by examinerClassifications U.S. Classification219/716, 219/705, 219/708, 219/702, 315/224, 219/709, 219/704, 219/703International ClassificationG06N3/00, G06F15/18, H05B6/68Cooperative ClassificationH05B6/687, H05B6/6447, Y02B40/143European ClassificationH05B6/68C, H05B6/64SLegal EventsDateCodeEventDescriptionApr 7, 2006FPAYFee paymentYear of fee payment: 4Jun 7, 2010REMIMaintenance fee reminder mailedOct 29, 2010LAPSLapse for failure to pay maintenance feesDec 21, 2010FPExpired due to failure to pay maintenance feeEffective date: 20101029RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services