JPH11265A - Electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric rice cooker capable of appropriately cooking rice in accordance with the volume of rice to be cooked and more speedily cooking the rice. SOLUTION: This electric rice cooker is provided with an inner pot 7 for putting in a material 27 to be heated, heaters 11 and 12 for heating the inner pot 7, a temperature sensor 9 for detecting the temperature of inner pot 7, and a control means 20 for executing a water absorbing process and a rice cooking process while controlling the heaters 11 and 12 based on the temperature information from the temperature sensor 9. When the water absorbing process is started, the control means 20 performs heating through the heaters 11 and 12 until reaching a specified temperature, the volume of the material 27 is discriminated based on the relation between the temperature change of inner pot 7 and the time required for that temperature change, and time for the water absorbing process is varied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric rice cooker in which heating is controlled by a temperature sensor.

[0002]

2. Description of the Related Art In an electric rice cooker, a heated product such as rice is put into an inner pot, the temperature of the inner pot is detected by a temperature sensor, and heating is performed based on temperature information from the temperature sensor. The operation of the conventional electric rice cooker mainly includes a water absorption step J, a rice cooking step K, and a steaming step L as shown in FIG.

Further, the water absorption step J includes a preheating start-up step M for heating to a temperature Ta, and a preheating step N for keeping the temperature of the inner pot at the temperature Ta. On the other hand, the rice cooking process K
The process includes a rice cooking start-up process P for heating until boiling, a boiling maintenance process Q for maintaining the temperature in the boiling state Tb, and a cooking process H. If the temperature rises to the temperature Tc in the cooking step H, the steaming step L is entered, and the rice cooking is finished.

Normally, in a conventional electric rice cooker, the water absorption step J and the rice cooking step K are clearly distinguished, and in particular, the preheating step N
Was previously determined to be a fixed time regardless of the volume of the heated material. In FIG. 10, the solid line S indicates the temperature of the inner pot detected by the temperature sensor, and the dotted line R indicates the temperature of the heated object.

Further, as described in Japanese Patent Application Laid-Open No. 9-28564, a heater is controlled so as to keep the inner pot at a constant temperature Ta for a predetermined time in a preheating step N. In some cases, the capacity is determined based on the ratio between the time (ta + tb +...) And the rest time to control the heating rate in the rice cooking step K.

[0006]

However, the former electric rice cooker does not perform the rice cooking according to the capacity because the capacity is not determined. In addition, since the water absorption step J and the rice cooking step K are clearly distinguished and the period of the preheating step N is predetermined, unnecessary time may be included depending on the capacity of the heated material, and the rice cooking time may be longer. Had become a cause.

On the other hand, the latter electric rice cooker (JP-A-9-28-9)
564), the capacity of the heated material is determined.
Since the determination is made in the preheating step N, not only the preheating step N cannot be performed according to the capacity, but also the rice cooking time may become longer as described above, and the capacity is determined only once. There was a risk that the capacity determination would be inaccurate.

In both electric rice cookers, the temperature of the inner pot is maintained at a constant temperature Ta in the water absorption step J. However, as shown in FIG. 10, the temperature of the heated material does not easily reach the temperature Ta. There was a case. In particular, when the initial water temperature To is low, the tendency is strong, and it is not easy to appropriately maintain the temperature of the heated object.

The present invention solves the above problems,
It is an object of the present invention to provide an electric rice cooker that can cook rice appropriately in accordance with the volume of a heated object and can cook rice more quickly.

[0010]

According to a first aspect of the present invention, there is provided an inner pot for storing a heated object, a heater for heating the inner pot, and detecting a temperature of the inner pot. In an electric rice cooker comprising a temperature sensor and control means for controlling the heater based on temperature information from the temperature sensor to perform a water absorption step and a rice cooking step, the control means starts the water absorption step Heating is performed by the heater until the temperature reaches the first specific temperature, and the capacity of the heated object is determined based on the relationship between the temperature change of the inner pot and the time required for the temperature change, and the time of the water absorption step is determined. Is made to be variable.

According to such a configuration, the electric rice cooker first heats to the first specific temperature in the water absorption step. Then, for example, the capacity of the heated object is determined by measuring the time until the temperature reaches the specific temperature. For example, the electric rice cooker shortens the time of the water absorption step when the heated material has a large capacity. Even if the time of the water absorption step is short, it takes a long time to start the rice cooking, so that water is sufficiently absorbed into rice. vice versa,
When the capacity is small, the time of the water absorption step is increased so that the water absorption is sufficiently performed.

Further, in the second configuration of the present invention, the first
In the configuration described above, the control unit turns off the heater for a certain period after reaching the first specific temperature, and compares the temperature change due to the elapse of the period with a partition value to determine the magnitude of the capacity.

In such a configuration, after the heater is heated to the first specific temperature and the heater is turned off, the temperature change becomes large when the capacity of the heated object is large. By doing so, the magnitude of the capacity can be determined.

Further, in the third configuration of the present invention, the first
In the above configuration or the second configuration, in the water absorption step, the control unit turns off the heater after reaching the first specific temperature.

With such a configuration, the inner pot is once heated to a somewhat high temperature when the water absorption step is started. After that, if a time for turning off the heater is provided according to the capacity, water is absorbed into the rice during that period, and the same water absorbing effect as in the case of controlling to maintain a constant temperature can be obtained.

Further, in the fourth configuration of the present invention, the first
Or the second configuration, in the water absorption step, the control means controls the heater so as to maintain the inner pot at a constant temperature, and at that time, performs the heating by an integrated time in which the heater is turned on. The capacity of the object is determined.

According to such a configuration, the electric rice cooker once determines the capacity at the start of heating and then keeps the temperature at a constant temperature, and measures the cumulative time when the heater is turned on. When the integration time is long, it can be determined that the heating object has a large capacity, and when it is short, it can be determined that the heating object has a small capacity. As a result, the capacity determination is performed again, so that the determination becomes accurate. Further, heating control can be appropriately performed according to the capacity.

Also, in the fifth configuration of the present invention, the first
In any one of the above configurations to the fourth configuration, the control means varies a heating rate in a rice cooking start-up step of boiling the heated substance in the rice cooking step in accordance with a capacity of the heated substance.

According to such a configuration, when the capacity of the heating object is large, the electric rice cooker increases the heating rate in the rice cooking start-up process. Thereby, it can cook at a stretch. Conversely, when the capacity is small, the heating rate is reduced to prevent overheating.

Further, in the sixth configuration of the present invention, the first
In any one of the above configurations to the fifth configuration, the control unit determines a capacity of the heated object by a time until the heated object reaches a second specific temperature by heating in the rice cooking start-up step. I have.

According to such a configuration, the size of the electric rice cooker can be determined depending on whether the electric rice cooker starts up quickly or slowly at the start-up stage of the rice cooking process. The electric rice cooker performs heating control based on this determination. Since the capacity is determined not only at the start of the water absorption step but also at the start of the rice cooking step, the accuracy of the determination is further increased.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is an external view of the electric rice cooker of the present embodiment. As a basic structure, the electric rice cooker includes a cooker main body 1 and a lid 2, and FIG. 1 shows a state where the lid 2 is opened. Power is supplied to the cooker body 1 by a power cord 25.

A panel section 28 is provided on the front side of the main body 1 to input a signal by operating a switch, display a message, and the like. The main body 1 houses an inner pan 7. An inner lid 16, a steam packing 18, and a steam cap 19 are provided inside the lid 2.

FIG. 2 is a longitudinal sectional view of the electric rice cooker.
The cooker main body 1 includes a main body outer shell 3, a bottom lid 4, and an outer pot 5. The inner pan 7 housed inside the main body 1 is detachable. The heating heater includes a rice cooking heater 11 and a horizontal heater 12. The temperature detector for detecting the temperature of the inner pan 7 includes a heat-sensitive plate 8, a temperature sensor 9, and a temperature fuse 10.
If the temperature is excessively increased by the heaters 11 and 12, the circuit is cut by the thermal fuse 10.

A power cord 25 is provided at the bottom of the main body 1.
Power cord reel 13 for winding and storing (see FIG. 1)
Is provided. FIG. 2 shows a state where the power cord 25 is wound up. The lid 2 includes an outer lid 14, an outer lid cover 15, an inner lid 16, a lid heater 17, a steam packing 18, and a steam cap 19.

To cook rice, as shown in FIG.
, Water 26 and rice grains 27 are put into the vessel, and heating is started by the heaters 11 and 12. After that, based on the temperature information from the temperature sensor 9, the control board 20 causes the heaters 11, 12,
Control 17 During rice cooking, steam generated in the inner pan 7 passes through the steam cap 19 and the steam discharge passage 22 as shown by an arrow 21 and is discharged from the steam discharge port 23.

FIG. 3 shows a block diagram of the circuit of this embodiment. The control board 20 is control means for controlling the rice cooking heater 11, the horizontal heater 12, and the lid heater 17. Panel section 28
To send a signal to the control board 20 by a switch operation or the like, and display a message or the like by a signal from the control board 20. When the control board 20 starts heating, the control board 20 determines the capacity of the heating object based on the temperature information from the temperature sensor 9 and performs on / off control on each of the rice cooking heater 11, the horizontal heater 12, and the lid heater 17, Cook rice.

Next, the determination of the capacity of the heated object at the start of heating will be described with reference to FIGS. FIG. 4 shows the temperature of the heated object when the heated object has a large capacity, and the time of the temperature of the inner pot 7 detected by the temperature detecting unit constituted by the temperature sensor 9 and the like (hereinafter simply referred to as “temperature measuring unit temperature”). Indicates a change. FIG. 5 shows a temporal change in the temperature of the heated object and the temperature of the temperature measuring unit when the heated object has a small capacity. The time change of the temperature of the temperature detector is indicated by a solid line S,
The time change of the temperature of the heated object is indicated by a dotted line R.

In the preheating start-up step A, the electric rice cooker heats until the temperature of the temperature detecting unit reaches a specific temperature T ₁ irrespective of the designated rice cooking menu. Control board 2
At 0, a period T _A from the start of heating to the temperature T ₁ is measured. As can be seen from a comparison between FIG. 4 and FIG. 5, the larger the capacity, the longer the time T _A. For example, the control board 20 determines the capacity of the heated by comparing the partition value in the time T _A.

Alternatively, in order to reduce the influence of the initial temperature T ₀ on the determination, the capacity is not determined at the time T _A , and after the temperature T ₁ is reached, the heaters 11 and 12 are temporarily stopped to perform the capacity determination step B. I do. And it determines capacity by temperature T ₂ after a lapse of capacity determining step certain time t ₁₂ in B. In the present embodiment, when the temperature change (T ₁ −T ₂ ) is larger than a certain partition value α, it is determined that the capacity is large, and when it is small, it is determined that the capacity is small. Thus, the capacity of the heated object can be determined before the start of the preheating step C.

The lower waveforms in FIGS. 4 and 5 show the on / off states of the heaters 11 and 12. In the preheating start-up step A, the heaters 11 and 12 are in the ON state for the entire period. The heaters 11 and 12 may be turned on intermittently instead of being turned on all the time. Next, in the capacity determination step B, the heaters 11 and 12 are turned off.

Thereafter, in the preheating step C, the control board 20 controls the heaters 11 and 12 based on the temperature information from the temperature sensor 9 so that the temperature of the temperature detecting section becomes the temperature T ₃ . When the heated material has a large capacity, the preheating step C is performed at time t.
It carried out at _23, whereas, carried out at the time t ₂₄ when a small capacity.

Steps A, B and C are water absorption steps. After the preheating step C, the rice cooking step is started. In the rice cooking process, first, a rice cooking start-up process D is performed, and the control board 20 operates the heaters 11 and 12 at a high heating rate. Note that the heating rate refers to the ratio of the time during which the heaters 11 and 12 are turned on.

In the rice cooking start-up step D, when the heated material has a small capacity, it rises in a short time as shown in FIG. 5, so that the time t of the preheating step C is sufficient for the rice 27 to absorb water sufficiently. You need to take ₂₃ . On the other hand, when the heating material has a large capacity, as shown in FIG.
Even by shortening the time t ₂₃ the preheating step C it is possible to perform adequate water. Therefore, the time t ₂₃ shorter than t _24.

In the present embodiment, the capacity of the heated object is also determined in the preheating step C. Hereinafter, an example of the processing of the electric rice cooker including the capacity determination will be described with reference to a flowchart shown in FIG. 8 and FIGS. When heating is started, first, preheating start-up process A at the temperature measuring unit capacity determining step B the capacity determining step after the temperature has heated up to the temperature T ₁ I
Then, the temperature difference (T ₁ −T ₂ ) during the time t ₁₂ is compared with the partition value α. The capacity determination I may be determined by the time until the temperature T ₁ of the preheating start-up process A as described above.

In step S1, if T ₁ -T ₂ <α, the process proceeds to step S2, where it is determined that the heated object has a small capacity. The preheating step C next, during a certain time t ₂₄ which is predetermined, to keep the temperature measuring part temperature to the temperature T _3. On the other hand, if T ₁ −T ₂ ≧ α, the process proceeds to step S8, and it is determined that the heated object has a large capacity. Then, during the preheating step C, and the constant that is predetermined time t _23,
The temperature measuring part temperature to maintain the temperature T _3.

In the preheating step C, the electric rice cooker calculates the integrated time し た (ta +
tb + tc +...), and capacity determination II is performed in steps S3 and S9, respectively. Since heated is that the temperature of the heated object, as shown in FIG. 4, if a large capacity reaches the temperature T ₃ becomes slow, the integration time is lengthened. Therefore, the capacity can be determined by comparing this integrated time with a certain partition value.

If it is determined in step S2 that the heated object has a small capacity, the accumulated time Σ (ta) is determined in step S3.
+ Tb + tc +...) Is compared with the partition value β. Σ (ta
+ Tb + tc + ...)> β, the process proceeds to step S6, and it is determined that the capacity is medium. On the other hand, Σ (ta + tb +
If (tc + ...) ≤β, the process proceeds to step S4, and it is determined that the capacity is small.

If it is determined in step S8 that the heated object has a large capacity, the integrated time Σ (t) is determined in step S9.
a + tb + tc +...) are compared with the partition value γ. Time t
_{Since 23} is different from time t ₂₄ , the partition value γ is different from β.

Integration time Σ (ta + tb + tc +...) ≦ γ
In the case of, the process proceeds to step S6, and it is determined that the capacity is medium. On the other hand, when Σ (ta + tb + tc +...)> Γ, the process proceeds to step S10, and it is determined that the capacity is large. According to the capacity determinations I and II, any of the small capacity, medium capacity, and large capacity is determined, and the heating sequences S5, S7, and S1 are respectively performed.
In step 1, heating is performed in a heating sequence according to the capacity.
That is, the rice cooking start-up step D is performed, and the rice is boiled. Thereafter, a boiling maintaining process is performed, and the rice cooking is completed through a cooking process and a steaming process.

Further, the processing of the electric rice cooker can be performed as follows. That is, when the capacity of the heated object is determined to be large in the capacity determination I, the heating rate is increased in the rice cooking start-up step D as shown in FIG.
_{Assume 2} . On the other hand, when it is determined that the capacity is small, FIG.
As shown in the figure, in step D, the heating rate was reduced, and δ ₁
And Assuming that the on time per one cycle of the on and off of the heaters 11 and 12 is tx and ty, respectively, δ ₂ >
δ ₁ (tx> ty). In the rice cooking start-up step D, the times t ₅₆ and t ₅₇ until the specific temperature T ₄ is reached are measured, and the capacity is further determined.

FIG. 9 shows a flowchart of the processing of the electric rice cooker including the capacity determination. In step S1, capacity determination I is first performed, and if T1-T2 <α, step S20
To determine that the heated material has a small capacity. Next, in step S21, the heaters 11 and 12 are turned off for a certain period of time, and the period is set as a preheating step C. Then, in step S22, performs a cooking start-up at a heating rate of [delta] _1, measures the heating time t ₅₇ until the temperature T _4. In volume determination II, compared to the partition value delta ₁ with the heating time t _57, when the t _57> delta ₁ proceeds to step S6, is determined to be medium capacity. On the other hand, when the t ₅₇ ≦ Δ ₁ proceeds to step S4, determines that a small capacity.

On the other hand, in the capacity judgment I in step S1, T1-
When T2 ≧ α, the process proceeds to step S23, and it is determined that the heated object has a large capacity. Next, in step S24, the heater 11 is turned off for a fixed time according to the capacity. Then, a cooking start-up at a heating rate of [delta] ₂ at step S25, measures the heating time t ₅₆ until the temperature T _4. Note that the period of step S24 is shorter than the period of step S21.

The flow advances to step S10 at t ₅₆ ≧ Δ _2, determines that a large capacity. On the other hand, it is determined that when a t ₅₆ <delta ₂ is the volume in the flow proceeds to step S6.
Then, in steps S26, S27, and S28, heating is performed in a heating sequence suitable for each volume, and the rice cooking is completed.

According to the capacity determination I, when the heating object has a small capacity, the heaters 11 and 12 are turned off to take a longer pause time for absorbing water, while when the heating substance has a large capacity, the pause time is reduced. . In the case of a small capacity, since the temperature of the heated material rises in a short time in the rice cooking start-up step D, it is necessary to take a sufficient preheating time for water absorption, but in the case of a large capacity, the temperature rise is slow. Even if the preheating step C is short, water can be sufficiently absorbed. Therefore, the rice cooking time can be reduced. Even if the preheating step C is shortened, the capacity can be determined by the capacity determination II at the time of starting rice cooking, so that the heating rate of the rice cooking step can be appropriately determined.

In this embodiment, the outer shell 3 and the outer hook 5
Due to the heavy structure, in the preheating step C, there is no rapid temperature change of the heated object even without heating by the heater 11, and a sufficient water absorbing effect can be obtained. Since by heating until once the temperatures T ₁ in the preheating start-up process A, water can be temperature is ensured. Turning off the heaters 11 and 12 has a power saving effect. Further, since the heating is not performed in the preheating step C, the heater 1
Since the influences of 1 and 12 are less likely to occur, the accuracy of temperature detection is improved.

By combining the above three types of capacity determination,
Further, the judgment can be made more accurate. For example, in the water absorption step, heating is first stopped after heating to the temperature T ₁ , and in the capacity determination I, a temperature difference (T ₁ −T ₂ ) from the temperature T ₂ after a certain time t ₁₂ has elapsed is determined by a certain partition value α. And determine the capacity.

Next, in the capacity determination II, in the preheating step C, the temperature of the temperature detecting section is maintained at the temperature T ₃ , and the integrated time Σ (ta + tb + tc +...) In which the rice cooker 11 is turned on is determined by β and γ as partition values, respectively. Thereby, as described above, it is possible to determine any of the small capacity, the medium capacity, and the large capacity. Further subjected to heating at a heating rate corresponding to the volume when the cooking start up, weighing time t ₅₆ until the temperature is T ₄ from T _3, the capacity divider value determined respectively by the capacitors in the capacitive determination III judge.

Since the number of times of capacity determination is increased to three times, the accuracy of capacity determination is increased. For example, capacity judgment II and III
Are different from each other, the priority of the determination is determined in such a way that the determination is weighted to take a pause or the determination of the larger capacity is performed, so that the capacity determination becomes more accurate.

Alternatively, a small capacity, a medium capacity,
After the large capacity is divided, the capacity may be further divided in the capacity judgment III to perform heating in each heating sequence. This makes it possible to finely determine the heating rate in the rice cooking step according to the rice cooking capacity, and to cook delicious rice.

As described above, according to the present embodiment,
Regardless of the rice cooking menu, the temperature T ₁ higher than the temperature T ₃
Since the heating to the time-heated reaches the temperature T ₃ is shorter than conventional electronic cooker above. Thereby, water absorption into the rice 27 is promoted, and the rice cooking time is shortened. This is particularly effective when the initial water temperature To is low. In the preheating step C as in the processing example shown in FIG.
Even when 2 is turned off, water is absorbed sufficiently into rice.

Since the capacity is determined at the initial stage of heating,
The preheating step C can be set according to the capacity. Therefore, the rice grains are too sticky or too soft at the end of rice cooking due to excessive water absorption, and the hardness due to insufficient water absorption can be prevented beforehand, and delicious rice can be cooked at any capacity. In addition, since unnecessary water absorption time is omitted, rice cooking time can be reduced.

Since the capacity is determined many times, the heating sequence according to the capacity can be set in detail. When the capacity is small, in the rice cooking start-up step D, the heating rate can be reduced to prevent the rice grains from being damaged or sticky due to overheating. When the capacity is large, the heating rate can be increased to cook at a stretch. Further, since a plurality of capacity determinations are performed, the accuracy of the determination increases.

[0054]

【The invention's effect】

<Effect of Claim 1> As described above, according to the present invention, the electric rice cooker performs heating up to a specific temperature when the preheating step is started. Thereafter, for example, the capacity can be determined by comparing the time required to reach the first specific temperature with a certain partition value. Since the time of the preheating step of absorbing water into rice can be set by the determination of the capacity, unnecessary time is eliminated in the preheating step, and the rice cooking time is shortened. In addition, since excessive water absorption and insufficient water absorption can be prevented beforehand, the performance of rice cooking is stable, and delicious rice can be cooked at any capacity.

<Effect of Claim 2> Since the capacity is determined based on a temperature change after heating to the first specific temperature, the influence of the difference in the initial temperature on the determination is reduced.

<Effect of Claim 3> By setting the specific temperature higher, in the step of absorbing water into rice, water is sufficiently absorbed even when the heater is kept off. Since the heater is turned off, there is also a power saving effect, and the influence of the heater on the temperature sensor is reduced.

<Effect of Claim 4> Since the capacity can be determined by measuring the integrated time during which the heater is turned on in the preheating step, the accuracy of the determination is increased. In addition, it is possible to finely set the heating control according to the capacity.

<Effect of Claim 5> When the heated material has a small capacity, the heating rate is reduced in the rice cooking start-up step, so that damage and stickiness of rice grains due to overheating can be prevented.
Conversely, in the case of a large capacity, it is possible to bake delicious rice by raising the heating rate and cooking at once.

<Effect of Claim 6> The capacity of the heated object can be determined from the speed of temperature rise due to heating in the rice cooking start-up step. Further, by combining with the above-described capacity determination, it is possible to determine more accurately.

[Brief description of the drawings]

FIG. 1 is an external view of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view thereof.

FIG. 3 is a block diagram of the circuit.

FIG. 4 is a characteristic diagram showing a temperature change when the heating object has a large capacity in the capacity determination I.

FIG. 5 is a characteristic diagram showing a temperature change when the heating object has a small capacity in the capacity determination I.

FIG. 6 is a characteristic diagram showing a temperature change when the heating object has a large capacity in the capacity determination II.

FIG. 7 is a characteristic diagram showing a temperature change when a heated object has a large capacity in the capacity determination II.

FIG. 8 is a flowchart of an example of the processing.

FIG. 9 is a flowchart of another example of the process.

FIG. 10 is a characteristic diagram showing a temperature change of a conventional electric rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooker main body 2 Lid 3 Body outer shell 7 Inner pan 8 Heat-sensitive plate 9 Temperature sensor 11 Rice cooker 16 Inner lid 20 Control board 25 Power cord 26 Water 27 Rice grain 28 Panel part

Claims (6)

[Claims] 1. An inner pot for holding a heated object, a heater for heating the inner pot, a temperature sensor for detecting a temperature of the inner pot, and controlling the heater based on temperature information from the temperature sensor. In an electric rice cooker provided with control means for performing a water absorption step and a rice cooking step, the control means performs heating with the heater until a first specific temperature is reached when the water absorption step is started, An electric rice cooker characterized in that a capacity of the heated object is determined based on a relationship between a temperature change and a time required for the temperature change, and a time of the water absorption step is varied. 2. The method according to claim 1, wherein the control unit turns off the heater for a predetermined period after the temperature reaches the first specific temperature, and compares the temperature change due to the period with a partition value to determine the magnitude of the capacity. The electric rice cooker according to claim 1, characterized in that: 3. The electric rice cooker according to claim 1, wherein in the water absorption step, the control unit turns off the heater after the temperature reaches the first specific temperature. 4. In the water absorbing step, the control means controls the heater so as to maintain the inner pot at a constant temperature, and determines a capacity of the heated object based on an integrated time during which the heater is turned on. The electric rice cooker according to claim 1 or 2, wherein the electric rice cooker is used. 5. The heating means according to claim 1, wherein said control means varies a heating rate in a rice-starting step of boiling the heated substance in the rice cooking step in accordance with a capacity of the heated substance. An electric rice cooker according to any one of the above. 6. The controller according to claim 1, wherein the controller determines a capacity of the heated object by a time until the heated object reaches a second specific temperature by the heating in the rice cooking start-up step. An electric rice cooker according to claim 5.