Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments, filed 09/15/2025, with respect to the 35 USC § 103 rejection(s) have been fully considered and are persuasive in view of the amendments to the claims. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Frank (DE102020115842B3).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-2, 6, 9-11 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto (US20150144074A1) in view of Frank (DE102020115842B3), referring to the English translation dated 12/16/2025, and Tong (CN113091309B), referring to the English translation dated 03/05/2024.
Regarding claim 1, Fujimoto teaches
a tankless liquid heater system (water heating apparatus 20) for detecting buildup on a heating element, the tankless liquid heater system comprising:
a chamber (case 1);
at least one heating element positioned inside the chamber and configured to heat liquid in the chamber (heat exchanger 3);
at least one sensor configured to detect data associated with identifying buildup on the at least one heating element (“Scale detector 8 detects occurrence of scale clogging in heat exchanger 3”) [0050]; and
at least one device (controller 10) configured to:
receive the data detected by the at least one sensor (“This controller 10 has a function of controlling each part so as to allow the notifying unit to notify an error and prohibit combustion of the burner after the error is notified, when scale detector 8 detects occurrence of scale clogging of an amount greater than or equal to a predetermined amount”) [0057]
determine, based on the data, an amount of the buildup on the at least one heating element (“Scale clogging determination unit 10c is configured to receive a detection value outputted from scale detector 8. This scale clogging determination unit 10c determines whether or not scale clogging occurs based on the detection value detected by scale detector 8”) [0064]; and
adjust an operation of the at least one heating element based on the amount of the buildup on the at least one heating element (“This controller 10 has a function of controlling each part so as to allow the notifying unit to notify an error and prohibit combustion of the burner after the error is notified, when scale detector 8 detects occurrence of scale clogging of an amount greater than or equal to a predetermined amount”) [0057]
Fujimoto does not teach
at least one electrical resistance heating element
wherein the at least one sensor comprises at least one of an infrared sensor, resistive sensors, or a touch sensor
wherein the data comprise at least one of infrared image data of the at least one electrical resistance heating element, resistance at multiple locations of the at least one electrical resistance heating element, resistance at multiple locations in the chamber, or a touch-based pressure applied by contact with the at least one electrical resistance heating element
Frank teaches
at least one electrical resistance heating element (electrical heating resistance 7)
Fujimoto teaches the heating element of claim 1, however teaches heat exchanger 3 comprising a burner 4, and thus does not teach the heating element as an electrical resistance heating element. Frank teaches an instantaneous water heater electrical heating resistance 7, further comprising a strain gauge for monitoring “disruptions to the fluid circulation, such as through clogging or blockage” [0006]. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the scale detecting system of Fujimoto in combination with a water heater comprising an electrical resistance heating system (as taught in Frank) instead of the burner system of Fujimoto, in order to allow use of a buildup monitoring heater in a location where gas fuel is not available.
Tong teaches
wherein the at least one sensor comprises at least one of an infrared sensor (“The infrared thermal imager monitors the temperature of the pipe wall of the heating surface, inputs the measurement results into the pipe wall scaling detection module, and outputs the comparison detection results of the temperature of the pipe section at the measuring point. By comparison, it can be judged whether there is scaling on the pipe wall”) [0041], resistive sensors, or a touch sensor
wherein the data comprise at least one of infrared image data of the at least one electrical resistance heating element (the infrared thermal imager of Tong as applied to scale detector 8 of Fujimoto located on pipe though heat exchanger 3 of Fujimoto), resistance at multiple locations of the at least one electrical resistance heating element, resistance at multiple locations in the chamber, or a touch-based pressure applied by contact with the at least one electrical resistance heating element
Fujimoto teaches “This scale detector 8 is, for example, a thermistor (water heater body thermistor), and is arranged so as to detect an outlet temperature (water heater body temperature) which is a temperature of hot water immediately after being tapped from an outlet of heat exchanger 3” [0050], thus scale detector 8 comprising a thermistor temperature sensor. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the scale detector 8 as an infrared thermal imager, as taught in Tong, instead of a thermistor in order to allow temperature detection of the system without requiring direct contact of the heat exchanger tube; therefore, allowing sensor placement in a location within water heating apparatus 20 that is easier to replace in the event of malfunction.
Regarding claim 2, Fujimoto, as modified, teaches the tankless liquid heater system of claim 1,
wherein the at least one sensor further comprises a flow sensor, and wherein the data further comprise a flow rate of the liquid (“Further, other than scale detector 8 measuring a temperature of the water heater body like the water heater body thermistor, scale detector 8 may, for example, measure reduction in a flow rate of hot and cold water caused by scale clogging on a downstream of heat exchanger 3”) [0050]
Regarding claim 6, Fujimoto, as modified, teaches the tankless liquid heater system of claim 1,
wherein the infrared image data are indicative of a thickness of the buildup (“The infrared thermal imager monitors the temperature of the pipe wall of the heating surface, inputs the measurement results into the pipe wall scaling detection module, and outputs the comparison detection results of the temperature of the pipe section at the measuring point. By comparison, it can be judged whether there is scaling on the pipe wall”; judging that there is scaling on the pipe wall associated with greater buildup thickness) [0057]
Regarding claim 9, Fujimoto, as modified, teaches the tankless liquid heater system of claim 1,
wherein the at least one device is on or within the tankless liquid heater system (as shown on fig. 1, controller 10 is within water heating apparatus 20)
Regarding claim 10, Fujimoto, as modified, teaches the tankless liquid heater system of claim 1,
wherein the at least one device is remote from a device comprising the chamber, the at least one sensor, and the at least one electrical resistance heating element (“display unit 11 may be configured as a separate body from water heating apparatus 20 and mounted to a remote control device capable of remotely operating the water heating apparatus”; therefore, Fujimoto teaches that the control system may be remote from the water heating apparatus 20) [0055]
Regarding claim 11, Fujimoto, as modified, teaches the tankless liquid heater system of claim 1,
wherein the at least one device is further configured to generate an alert indicating the amount of the buildup on the at least one heating element (“Display unit 11 is configured to notify an error when scale detector 8 detects occurrence of scale clogging of an amount greater than or equal to a predetermined amount, and it can serve as a notifying unit. This display unit 11 is, for example, a liquid crystal display device. In the present embodiment, the case is described where display unit 11 is mounted to water heating apparatus 20. However, display unit 11 may be configured as a separate body from water heating apparatus 20 and mounted to a remote control device capable of remotely operating the water heating apparatus. Further, other than display unit 11, a speaker generating sound and the like may be employed as a notifying unit for notifying an error”) [0055]
Regarding claim 20, Fujimoto teaches
a method for detecting buildup on a heating element (“Scale detector 8 detects occurrence of scale clogging in heat exchanger 3”) [0050] of a tankless liquid heating system (water heating apparatus 20), the method comprising:
receiving, by a controller device of a tankless liquid heating system, sensor data from at least one sensor of the tankless liquid heating system (“This controller 10 has a function of controlling each part so as to allow the notifying unit to notify an error and prohibit combustion of the burner after the error is notified, when scale detector 8 detects occurrence of scale clogging of an amount greater than or equal to a predetermined amount”) [0057];
determining, by the controller device, based on the sensor data, an amount of buildup on at least one heating element of the tankless liquid heating system (“Scale clogging determination unit 10c is configured to receive a detection value outputted from scale detector 8. This scale clogging determination unit 10c determines whether or not scale clogging occurs based on the detection value detected by scale detector 8”) [0064]; and
adjusting, by the controller device, an operation of the at least one heating element based on the amount of the buildup on the at least one heating element (“This controller 10 has a function of controlling each part so as to allow the notifying unit to notify an error and prohibit combustion of the burner after the error is notified, when scale detector 8 detects occurrence of scale clogging of an amount greater than or equal to a predetermined amount”) [0057]
Fujimoto does not teach
wherein the at least one sensor comprises at least one of an infrared sensor, resistive sensors, or a touch sensor, and wherein the data comprise at least one of infrared image data of at least one electrical resistance heating element, resistance at multiple locations of the at least one electrical resistance heating element, resistance at multiple locations in a chamber, or a touch-based pressure applied by contact with the at least one electrical resistance heating element
Frank teaches
at least one electrical resistance heating element (electrical heating resistance 7)
Fujimoto teaches a heating element of a water heating apparatus 20, however teaches heat exchanger 3 comprising a burner 4, and thus does not teach the heating element as an electrical resistance heating element. Frank teaches an instantaneous water heater electrical heating resistance 7, further comprising a strain gauge for monitoring “disruptions to the fluid circulation, such as through clogging or blockage” [0006]. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the scale detecting system of Fujimoto in combination with a water heater comprising an electrical resistance heating system (as taught in Frank) instead of the burner system of Fujimoto, in order to allow use of a buildup monitoring heater in a location where gas fuel is not available.
Tong teaches
wherein the at least one sensor comprises at least one of an infrared sensor (“The infrared thermal imager monitors the temperature of the pipe wall of the heating surface, inputs the measurement results into the pipe wall scaling detection module, and outputs the comparison detection results of the temperature of the pipe section at the measuring point. By comparison, it can be judged whether there is scaling on the pipe wall”) [0041], resistive sensors, or a touch sensor, and wherein the data comprise at least one of infrared image data of the at least one heating element (the infrared thermal imager of Tong as applied to scale detector 8 of Fujimoto located on pipe though heat exchanger 3 of Fujimoto), resistance at multiple locations of the at least one heating element, resistance at multiple locations in a chamber, or a touch-based pressure applied by contact with the at least one heating element
Fujimoto teaches “This scale detector 8 is, for example, a thermistor (water heater body thermistor), and is arranged so as to detect an outlet temperature (water heater body temperature) which is a temperature of hot water immediately after being tapped from an outlet of heat exchanger 3” [0050], thus scale detector 8 comprising a thermistor temperature sensor. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the scale detector 8 as an infrared thermal imager, as taught in Tong, instead of a thermistor in order to allow temperature detection of the system without requiring direct contact of the heat exchanger tube; therefore, allowing sensor placement in a location within water heating apparatus 20 that is easier to replace in the event of malfunction.
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto (US20150144074A1), Frank (DE102020115842B3), referring to the English translation dated 12/16/2025, and Tong (CN113091309B), referring to the English translation dated 03/05/2024, in further view of Fujimoto2014 (US20140060458A1).
Regarding claim 3, Fujimoto, as modified, does not teach the tankless liquid heater system of claim 1,
wherein the at least one sensor further comprises an inlet temperature sensor, and wherein the data further comprise an inlet temperature of the liquid
Fujimoto2014 teaches
wherein the at least one sensor further comprises an inlet temperature sensor, and wherein the data further comprise an inlet temperature of the liquid (temperature sensor Sa as shown on fig. 1)
[0064] of Fujimoto teaches “Scale clogging determination unit 10c is configured to receive a detection value outputted from scale detector 8. This scale clogging determination unit 10c determines whether or not scale clogging occurs based on the detection value detected by scale detector 8. In the case where scale detector 8 is, for example, a water heater body thermistor, scale clogging determination unit 10c serves as a temperature determination unit for determining whether or not a temperature rise detected by the water heater body thermistor after hot water supplying operation is stopped (referred to as “post-boiling temperature”) is higher than or equal to a predetermined temperature”. Therefore, since the scale clogging determination unit 10c of the controller 10 determines the temperature rise within the system, the scale clogging determination unit 10c must be provided with data relating the to the initial temperature of the water. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the temperature sensor Sa at the inlet of the system of Fujimoto2014 to Fujimoto, in order to provide temperature data at the inlet of the water heating apparatus 20 so scale clogging determination unit 10c can perform an accurate temperature rise determination.
Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto (US20150144074A1) in view of Frank (DE102020115842B3), referring to the English translation dated 12/16/2025, and Tong (CN113091309B), referring to the English translation dated 03/05/2024, in further view of Azevedo (ES2546117A2), referring to the English translation dated 03/05/2024.
Regarding claim 4, Fujimoto, as modified, does not teach the tankless liquid heater system of claim 1,
wherein the at least one sensor further comprises an outlet temperature sensor, and wherein the data further comprise an outlet temperature of the liquid
Azevedo teaches
wherein the at least one sensor further comprises an outlet temperature sensor, and wherein the data further comprise an outlet temperature of the liquid (“The water temperature is preferably determined via a temperature sensor output 7 which is arranged in a second water conduit 8 in flow direction behind the heat exchanger 3. If additionally or alternatively the temperature sensor output 7 in the area of the heat exchanger 3 are provided other temperature sensors can be determined additional water temperature or alternatively at the corresponding points of the heat exchanger 3”) [0073]
As shown on fig. 1, the system of Azevedo teaches temperature sensor output 7 on the outlet side of heat exchanger 3, however further discloses the use of additional temperature sensors in the system. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide additional temperature sensors, in additional to scale detector 8, to the system of Fujimoto, as modified, in order to obtain additional data in the event of sensor malfunction.
Regarding claim 5, Fujimoto, as modified, does not teach the tankless liquid heater system of claim 1,
wherein the at least one sensor further comprises a temperature sensor configured to detect the temperature of the at least one heating element, and wherein the data further comprise the temperature of the at least one heating element
Azevedo teaches
wherein the at least one sensor further comprises a temperature sensor configured to detect the temperature of the at least one electrical resistance heating element, and wherein the data further comprise the temperature of the at least one electrical resistance heating element (“The water temperature is preferably determined via a temperature sensor output 7 which is arranged in a second water conduit 8 in flow direction behind the heat exchanger 3. If additionally or alternatively the temperature sensor output 7 in the area of the heat exchanger 3 are provided other temperature sensors can be determined additional water temperature or alternatively at the corresponding points of the heat exchanger 3”) [0073]
As shown on fig. 1, the system of Azevedo teaches temperature sensor output 7 on the outlet side of heat exchanger 3, however further discloses the use of additional temperature sensors on the heat exchanger 3. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide additional temperature sensors, in additional to scale detector 8, to the system of Fujimoto in order to obtain additional data in the event of sensor malfunction (As described in [0015] of Frank, the electrical resistance heating element also comprises a temperature sensor 12, thus allowing this modification).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto (US20150144074A1), Frank (DE102020115842B3), referring to the English translation dated 12/16/2025, and Tong (CN113091309B), referring to the English translation dated 03/05/2024, in further view of Sakaguchi (US20220235945A1).
Regarding claim 7, Fujimoto, as modified, does not teach the tankless liquid heater system of claim 1,
wherein the at least one sensor further comprises a pressure sensor, and wherein the data further comprise a pressure of the liquid
Sakaguchi teaches
wherein the at least one sensor further comprises a pressure sensor, and wherein the data further comprise a pressure of the liquid (“In Step St 1 , the heating operation starts. In Step St 2 , the temperature sensor ( 61 ) detects the temperature Tw of the water in the water circuit ( 50 ). In Step St 3 , the pressure sensor ( 60 ) detects the pressure Pw of the water in the water circuit ( 50 ). In Step St 4 , a time measurement unit of the controller ( 80 ) measures operation time ΔT 1 of the heating operation. In Step St 5 , a calculation unit of the controller ( 80 ) calculates an integrated value I based on the temperature Tw, the pressure Pw, and the operation time ΔT 1 . The integrated value I is an index for estimating the amount of scale in the water. This is because the scale amount in the water varies depending on the temperature and pressure of the water and the operation time of the first operation”) [0066]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide a pressure sensor in addition to the temperature sensor of the system of Fujimoto, as modified (wherein the “infrared thermal imager monitors the temperature of the pipe wall” [0041] of Tong), as taught in Sakaguchi, in order to provide another method of measurement of the buildup within the system; thus improving the accuracy of the measurement relative to a predetermined threshold.
Claim(s) 12-16 and 20-22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto2014 (US20140060458A1) in view of Frank (DE102020115842B3), referring to the English translation dated 12/16/2025, and Fujimoto (US20150144074A1).
Regarding claim 12, Fujimoto2014 teaches
a tankless liquid heater device (latent heat recovery type water heater A) for detecting buildup on a heating element (“The present invention relates to a latent heat recovery type water heater, more particularly to a latent heat recovery type water heater capable of detecting an abnormality such as scale adherence or exhaust clogging”) [0002], the tankless liquid heater device configured to:
receive, from at least one sensor configured to detect data associated with identifying buildup on at least one heating element positioned in a chamber and configured to heat liquid in the chamber, the data (“When water is supplied to the secondary heat exchanger 2 and to the primary heat exchanger 1 and the burner 3 starts combustion drive, the controller 4 executes arithmetic operation of the heat exchange efficiency η of the secondary heat exchanger 2 (S 1 ). The heat exchange efficiency η is obtained by the following formula 1… Q 1 is the heated amount of water by the secondary heat exchanger 2 and is obtained by the formula Q 1 =(T 2 -T 1 )·W, wherein T 1 is the inflow water temperature, T 2 is the outflow water temperature from the secondary heat exchanger 2 , and W is the inflow amount of water. These values are detected by the temperature sensors Sa, Sb and the flow rate sensor Sc” [0030-0031]; casing of latent heat recovery type water heater A, which reads on chamber, inherent to a water heater system);
determine, based on the data, an amount of the buildup on the at least one heating element (“the controller 4 determines whether the primary heat exchanger 1 has an abnormality such as scale adherence”) [0027]; and
adjust an operation of the at least one heating element based on the amount of the buildup on the at least one heating element (“the controller 4 selects data of the threshold value Th corresponding to the inflow water temperature T 1 from the data D 1 shown in FIG. 2 and compares the threshold value Th with the above-mentioned heat exchange efficiency η (S 2 , S 3 ). When the formula η>Th is established by the comparison and is kept for a predetermined time, an abnormality such as scale adherence or exhaust clogging in the primary heat exchanger 1 is detected (S 3 :YES, S 4 :YES, S 5 ). In such a case, alarm informing abnormality is operated or the burner 3 stops operation”) [0033]
Fujimoto2014 does not teach
at least one electrical resistance heating element
wherein the at least one sensor comprises at least one of resistive sensors or a touch sensor, and wherein the data comprise at least one of resistance at multiple locations of the at least one heating element, resistance at multiple locations in a chamber, or a touch-based pressure applied by contact with the at least one heating element
wherein when the data comprise the resistance at multiple locations in the chamber, to determine the amount of scale buildup on the at least one electrical resistance heating element is based on a static resistance of the at least one electrical resistance heating element
Frank teaches
at least one electrical resistance heating element (electrical heating resistance 7)
Fujimoto2014 teaches a heating element of latent heat recovery type water heater A, however teaches a secondary heat exchanger 2 and primary heat exchanger 1 in combination with burner 3, and thus does not teach the heating element as an electrical resistance heating element. Frank teaches an instantaneous water heater electrical heating resistance 7, further comprising a strain gauge for monitoring “disruptions to the fluid circulation, such as through clogging or blockage” [0006]. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the scale detecting system of Fujimoto2014 in combination with a water heater comprising an electrical resistance heating system (as taught in Frank) instead of the burner system of Fujimoto2014, in order to allow use of a buildup monitoring heater in a location where gas fuel is not available.
Fujimoto teaches
wherein the at least one sensor comprises at least one of resistive sensors (“This scale detector 8 is, for example, a thermistor (water heater body thermistor), and is arranged so as to detect an outlet temperature (water heater body temperature) which is a temperature of hot water immediately after being tapped from an outlet of heat exchanger 3” [0050]; thermistor changes resistance with changing temperature) or a touch sensor, and wherein the data comprise at least one of resistance at multiple locations of the at least one heating element (“The flow paths 51, 52 have temperature sensors Sa, Sb for detecting the temperature of inflow water and the temperature of the outflow water from the secondary heat exchanger 2” [0026 of Fujimoto2014]; as modified by Fujimoto, thermistor resistance at these locations), resistance at multiple locations in a chamber, or a touch-based pressure applied by contact with the at least one heating element
wherein when the data comprise the resistance at multiple locations in the chamber, to determine the amount of scale buildup on the at least one electrical resistance heating element is based on a static resistance of the at least one electrical resistance heating element (contingent limitation; not required since Fujimoto does not rely upon “when the data comprise the resistance at multiple locations in the chamber” to teach the claim)
The system of Fujimoto2014 teaches temperature sensors Sa, Sb but does not disclose the type of temperature sensors used. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the temperature sensors Sa, Sb of Fujimoto2014 as thermistors, as taught by Fujimoto, which comprises a similar scale detection system, due to their low cost and accessibility.
Regarding claim 13, Fujimoto2014, as modified, teaches the tankless liquid heater device of claim 12,
wherein the data comprise a flow rate of the liquid (flow rate sensor Sc is used to compute Q1 as taught regarding claim 12)
Regarding claim 14, Fujimoto2014, as modified, teaches the tankless liquid heater device of claim 12,
wherein the data further comprise an inlet temperature of the liquid (temperature sensor Sa as shown on fig. 1)
Regarding claim 15, Fujimoto2014, as modified, teaches the tankless liquid heater device of claim 12,
wherein the data further comprise an outlet temperature of the liquid (temperature sensor Sb as shown on fig. 1)
Regarding claim 16, Fujimoto2014, as modified, does not teach the tankless liquid heater device of claim 12,
wherein the data comprise a temperature of the at least one heating element
Fujimoto teaches
wherein the data comprise a temperature of the at least one electrical resistance heating element (“Scale detector 8 detects occurrence of scale clogging in heat exchanger 3. This scale detector 8 is, for example, a thermistor (water heater body thermistor), and is arranged so as to detect an outlet temperature (water heater body temperature) which is a temperature of hot water immediately after being tapped from an outlet of heat exchanger 3. This scale detector 8… may be arranged at the heat-transfer pipe inside heat exchanger 3”) [0050]
While Fujimoto teaches temperature sensor Sb at the outlet of heat exchanger 2 as shown on fig. 1, it does not teach it explicitly within heat exchanger 2 as taught by Fujimoto. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide temperature sensor Sb “arranged at the heat-transfer pipe inside heat exchanger” [0050 of Fujimoto], as taught by Fujimoto, in order to obtain a temperature measurement of the heated water prior to exiting the heat exchanger (wherein after exiting the heat exchanger, it would be at a stage where temperature is beginning to cool), in order to comprise a temperature measurement that is as accurate as possible to the water temperature exiting the heat exchanger (As described in [0015] of Frank, the electrical resistance heating element also comprises a temperature sensor 12, thus allowing this modification).
Regarding claim 20, Fujimoto2014 teaches
a method for detecting buildup on a heating element (“The present invention relates to a latent heat recovery type water heater, more particularly to a latent heat recovery type water heater capable of detecting an abnormality such as scale adherence or exhaust clogging”) [0002] of a tankless liquid heating system (latent heat recovery type water heater A), the method comprising:
receiving, by a controller device of a tankless liquid heating system, sensor data from at least one sensor of the tankless liquid heating system (“When water is supplied to the secondary heat exchanger 2 and to the primary heat exchanger 1 and the burner 3 starts combustion drive, the controller 4 executes arithmetic operation of the heat exchange efficiency η of the secondary heat exchanger 2 (S 1 ). The heat exchange efficiency η is obtained by the following formula 1… Q 1 is the heated amount of water by the secondary heat exchanger 2 and is obtained by the formula Q 1 =(T 2 -T 1 )·W, wherein T 1 is the inflow water temperature, T 2 is the outflow water temperature from the secondary heat exchanger 2 , and W is the inflow amount of water. These values are detected by the temperature sensors Sa, Sb and the flow rate sensor Sc”) [0030-0031];
determining, by the controller device, based on the sensor data, an amount of buildup on at least one heating element of the tankless liquid heating system (“the controller 4 determines whether the primary heat exchanger 1 has an abnormality such as scale adherence”) [0027]; and
adjusting, by the controller device, an operation of the at least one heating element based on the amount of the buildup on the at least one heating element (“the controller 4 selects data of the threshold value Th corresponding to the inflow water temperature T 1 from the data D 1 shown in FIG. 2 and compares the threshold value Th with the above-mentioned heat exchange efficiency η (S 2 , S 3 ). When the formula η>Th is established by the comparison and is kept for a predetermined time, an abnormality such as scale adherence or exhaust clogging in the primary heat exchanger 1 is detected (S 3 :YES, S 4 :YES, S 5 ). In such a case, alarm informing abnormality is operated or the burner 3 stops operation”) [0033]
Fujimoto2014 does not teach
at least one electrical resistance heating element
wherein the at least one sensor comprises at least one of an infrared sensor, resistive sensors, or a touch sensor, and wherein the data comprise at least one of infrared image data of the at least one electrical resistance heating element, resistance at multiple locations of the at least one electrical resistance heating element, resistance at multiple locations in a chamber, or a touch-based pressure applied by contact with the at least one electrical resistance heating element
Frank teaches
at least one electrical resistance heating element (electrical heating resistance 7)
Fujimoto2014 teaches a heating element of latent heat recovery type water heater A, however teaches a secondary heat exchanger 2 and primary heat exchanger 1 in combination with burner 3, and thus does not teach the heating element as an electrical resistance heating element. Frank teaches an instantaneous water heater electrical heating resistance 7, further comprising a strain gauge for monitoring “disruptions to the fluid circulation, such as through clogging or blockage” [0006]. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the scale detecting system of Fujimoto2014 in combination with a water heater comprising an electrical resistance heating system (as taught in Frank) instead of the burner system of Fujimoto2014, in order to allow use of a buildup monitoring heater in a location where gas fuel is not available.
Fujimoto teaches
wherein the at least one sensor comprises at least one of an infrared sensor, resistive sensors (“This scale detector 8 is, for example, a thermistor (water heater body thermistor), and is arranged so as to detect an outlet temperature (water heater body temperature) which is a temperature of hot water immediately after being tapped from an outlet of heat exchanger 3” [0050]; thermistor changes resistance with changing temperature), or a touch sensor, and wherein the data comprise at least one of infrared image data of the at least one heating element, resistance at multiple locations of the at least one electrical resistance heating element (“The flow paths 51, 52 have temperature sensors Sa, Sb for detecting the temperature of inflow water and the temperature of the outflow water from the secondary heat exchanger 2” [0026 of Fujimoto2014]; as modified by Fujimoto, thermistor resistance at these locations), resistance at multiple locations in a chamber (Sa and Sb within chamber as shown on fig. 1 of Fujimoto2014) , or a touch-based pressure applied by contact with the at least one heating element
The system of Fujimoto2014 teaches temperature sensors Sa, Sb but does not disclose the type of temperature sensors used. Thus, It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the temperature sensors Sa, Sb of Fujimoto2014 as thermistors, as taught by Fujimoto, which comprises a similar scale detection system, due to their low cost and accessibility.
Regarding claim 21, Fujimoto2014, as modified, teaches the method of claim 20, wherein determining the amount of buildup further comprises:
determining, based on the resistance at multiple locations of the at least one electrical resistance heating element, a sum of resistance at a first location of the at least one heating element (via temperature sensor Sa, modified by Fujimoto to comprise thermistor) and a resistance at a second location of the at least one electrical resistance heating element (via temperature sensor Sb, modified by Fujimoto to comprise thermistor)
Regarding claim 22, Fujimoto2014, as modified, teaches the method of claim 20, wherein determining the amount of buildup further comprises:
determining, based on the resistance at multiple locations in the chamber, a sum of resistance at a first location in the chamber (via temperature sensor Sa, modified by Fujimoto to comprise thermistor) and a resistance at a second location in the chamber (via temperature sensor Sb, modified by Fujimoto to comprise thermistor)
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto2014 (US20140060458A1) in view of Frank (DE102020115842B3), referring to the English translation dated 12/16/2025, and Fujimoto (US20150144074A1), in further view of Tong (CN113091309B), referring to the English translation dated 03/05/2024.
Regarding claim 17, Fujimoto2014, as modified, teaches the tankless liquid heater device of claim 12,
wherein the at least one sensor comprises an infrared sensor, wherein the data further comprise infrared image data indicative of a thickness of the buildup, and wherein to determine the amount of buildup on the at least one electrical resistance heating element is based on a comparison of the infrared image data to previous infrared image data indicative of a previous buildup on the at least one electrical resistance heating element
Tong teaches
wherein the at least one sensor comprises an infrared sensor, wherein the data further comprise infrared image data indicative of a thickness of the buildup, and wherein to determine the amount of buildup on the at least one electrical resistance heating element is based on a comparison of the infrared image data to previous infrared image data indicative of a previous buildup on the at least one electrical resistance heating element (“The infrared thermal imager monitors the temperature of the pipe wall of the heating surface, inputs the measurement results into the pipe wall scaling detection module, and outputs the comparison detection results of the temperature of the pipe section at the measuring point. By comparison, it can be judged whether there is scaling on the pipe wall”; judging that there is scaling on the pipe wall associated with greater buildup thickness) [0057]
Fujimoto2014, as modified, teaches a temperature sensor system comprising temperature sensors Sa and Sb to determine scale buildup. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide an additional infrared thermal imager, as taught in Tong, to the system in order to allow an additional temperature detection of the system that doesn’t require direct contact of the heat exchanger tube, in order to obtain additional data in the event of sensor malfunction.
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto2014 (US20140060458A1) in view of Frank (DE102020115842B3), referring to the English translation dated 12/16/2025, and Fujimoto (US20150144074A1), in further view of Sakaguchi (US20220235945A1).
Regarding claim 18, Fujimoto2014, as modified, does not teach the tankless liquid heater device of claim 12,
wherein the data further comprise a pressure of the liquid
Sakaguchi teaches
wherein the data further comprise a pressure of the liquid (“In Step St 1 , the heating operation starts. In Step St 2 , the temperature sensor ( 61 ) detects the temperature Tw of the water in the water circuit ( 50 ). In Step St 3 , the pressure sensor ( 60 ) detects the pressure Pw of the water in the water circuit ( 50 ). In Step St 4 , a time measurement unit of the controller ( 80 ) measures operation time ΔT 1 of the heating operation. In Step St 5 , a calculation unit of the controller ( 80 ) calculates an integrated value I based on the temperature Tw, the pressure Pw, and the operation time ΔT 1 . The integrated value I is an index for estimating the amount of scale in the water. This is because the scale amount in the water varies depending on the temperature and pressure of the water and the operation time of the first operation”) [0066]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide a pressure sensor in addition to the temperature sensors of the system of Fujimoto2014, as modified, as taught in Sakaguchi, in order to provide another method of measurement of the buildup within the system; thus improving the accuracy of the measurement relative to a predetermined threshold.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/BRETT P. MALLON/Examiner, Art Unit 3762 /MICHAEL G HOANG/Supervisory Patent Examiner, Art Unit 3762
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