JPH0228059B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a display for a heating device. Conventional configurations and their problems As semiconductor technology advances, microcomputers and sensors are being introduced to control home appliances such as microwave ovens and microwave ovens that are combination products of microwave ovens and ovens. There are some remarkable changes as well. Furthermore, microcomputers and various sensors have made it possible to perform automatic cooking control and complex cooking that were previously unimaginable. However, having such a large number of cooking functions unfortunately results in complicated operations for the user, considering that this device is mainly used by housewives and others. Improving its operability and pursuing ease of use were major challenges. Various devices have been proposed in the past with the aim of improving usability, such as displaying the type of cooking menu, type of heating method, cooking time, heating setting temperature, etc. using a fluorescent display tube composed of multicolored luminescent materials. There are some methods that try to improve the operability depending on the situation. FIG. 1 is a perspective view of the main body of a microwave oven as an example of a heating device having such a multicolor fluorescent display device. The main body 1 has, on the front, a door body 2 which is pivotally supported so that it can be opened and closed, a menu key 3 for inputting cooking menu selections to the control system, a temperature control key 4 for setting the heating temperature, and a timer volume 5 for setting the cooking time. and an operation panel 7 on which a display section 6 composed of a multicolor fluorescent display tube or the like is arranged. 8 is a start switch for instructing the start of cooking. FIG. 2 shows an enlarged view of the operation panel 7 shown in FIG. Now, based on FIG. 2, a conventional operating method and its display form will be described. The five menu keys 3a, 3b, 3c, 3d, and 3e are used to set manual cooking (cooking according to the user's own preferences).When key 3a is input, the cooking type is set to microwave oven. At this time, the display piece 6a of the display unit 6 lights up to indicate to the user that "high electric" cooking has been set. After that, the user uses timer volume 5 to "Electric Strong"
The heating time for cooking is set, and the set value is represented as a maximum of four digit numbers by a group of display pieces 6i arranged in the shape of four "day" characters. When the setting of the cooking time is completed, the start switch 8 instructs the control unit to start cooking, and the actual cooking begins.The set cooking time is decremented by one every second, and the cooking is started. In order to show that it is inside, the display piece 6b of "Electric Strong" starts blinking. Normally, the period of this blinking operation is 1 second (700 milliseconds on, 300 milliseconds off). In this way, the above operation continues until the cooking time displayed on the display strip group 6i reaches "0", and when the cooking time runs out, the series of heating cooking is completed. At this time, a buzzer or other means is generally used to notify that the cooking has been completed. Further, when the cooking is completed, the display form of the display unit 6 immediately returns to the state before inputting the menu key. Similarly, to select "Electric Low" cooking (low output operation of the microwave oven), input the menu key 3b. At this time, the display piece 6c lights up, indicating that "Electric Low" cooking has been set.
In addition, in the case of "Grill" cooking, the display piece 6d lights up by pressing the menu key 3c, in the case of "Oven" cooking, the display part 6e lights up by pressing the menu key 3d, and in the case of "Oven Preheat" cooking, the display piece 6d lights up. By pressing the display piece 6e and the display piece 6 for indicating the cooking mode of "Oven Preheat"
Menu keys 3f to 3m, on which ``g'' and ``g'' are lit, are used to select automatic cooking using a sensor, etc. At this time, a display piece 6a indicating "auto" cooking is lit. At this time, for cooking that requires wrapping, the display piece 6f lights up to inform the user. In addition, when a frozen product such as "Frozen Delicious" is thawed, the display panel 6h lights up. Next, a conventional example of a series of operations and display forms during "oven preheating" cooking, which is the subject of this application, will be explained in detail. "Oven preheating" cooking is cooking in which the temperature in the heating chamber is heated to a certain desired set temperature, and is used to bring the temperature in the heating chamber to the optimum temperature for oven cooking prior to oven cooking of bread, cookies, cakes, etc. belongs to. Therefore, no object to be heated is placed in the heating chamber, and the heating chamber is left empty, and only the preset heating temperature is adjusted using the temperature control keys 4a and 4b before cooking is started. In other words, "Oven Preheat" cooking menu key 3e
After entering , press down key 4 to lower the temperature.
By inputting a, the set temperature can be adjusted upward by 10 degrees, and if the user wishes to raise the set temperature by inputting the up key 4b, the setting can be adjusted upward by 10 degrees. At this time,
As for the status of the display section 6, a display piece 6e indicating that the cooking mode is "Oven" and a display piece 6g indicating that the cooking style is "Preheating" are lit, and the temperature is set using the temperature adjustment keys 4a and 4b. The preheating set temperature is indicated by the display strip group 6j. This display group 6j is composed of 16 display pieces, each of which has an angle of 10 degrees from 100 degrees to 250 degrees.
It corresponds to temperature values in degree increments, and if 250 degrees is currently set and input, there will be 16 display pieces from the display piece corresponding to 100 degrees to the display piece corresponding to 250 degrees as shown in Figure 2. 200 will all be lit.
If you have set the degree, only the five display pieces from the rightmost display piece corresponding to 250 degrees to the fifth display piece from the right end corresponding to 210 degrees will be turned off.
The remaining 11 display pieces, from the display piece corresponding to 210 degrees to the display piece corresponding to 100 degrees, will be lit. On the other hand, if the temperature inside the heating chamber is 100 degrees (Celsius) or higher, the set temperature display strip group 6j will be displayed in 10 degree increments.
It is displayed by blinking the display piece of the corresponding temperature value. The cycle of the blinking operation at this time is 1 second (700 milliseconds on, 300 milliseconds off). FIG. 3 shows the display state of the display section 6 when "oven preheat" cooking is executed at a set temperature of 200 degrees.
When the start of heating is commanded by the start key 8, as shown in FIG. 3a, the display piece 6e indicating "oven" heating starts blinking (with a cycle of 1 second) to indicate that cooking is in progress. As described above, the heating chamber temperature at that time is displayed by blinking the corresponding temperature display piece. After this, heating cooking progresses,
As the heating chamber temperature rises, the blinking display of the heating chamber temperature also moves to the right. Finally, the set temperature of 200 degrees is reached, as shown in Figure 3b. After this, the heat retention operation continues at the set temperature of 200 degrees until the door body 2 can be opened. By the way, the point at which the user determines that "oven preheating" cooking is complete is, of course, when the blinking temperature display indicating the temperature in the heating chamber reaches the desired set temperature. The preheating operation can be completed at the time when the preheating operation is completed, but in the case of a conventional system where the temperature is displayed as discrete values, the actual temperature and the display may be different for reasons that will be explained later. Because there are cases where a discrepancy occurs in the relationship with the temperature, for the user, just because the blinking display of the heating chamber temperature is at the set temperature value does not necessarily mean that preheating cooking is complete. . In other words, using FIG. 3b as an example, there are cases where the actual temperature has not reached 200 degrees even though the blinking display of the temperature in the heating chamber is 200 degrees as shown in the figure. Now, we will explain why there is a discrepancy in the relationship between the actual temperature and the displayed temperature. First, FIG. 4 is a circuit diagram showing a conventional example of the main part of a control circuit using a microcomputer with an A/D conversion function as a control section. Various cooking menu keys are arranged in the matrix 10 _, and _each key input is sent to _the microcomputer _'s input ports _I3 , _{I2 ,}
Input to I ₁ and I ₀ . On the other hand, this same scan signal is used to strobe the grid portion of the fluorescent display tube 6. The driving terminals of the anode segment of the display tube are ports _D0 to _D7 . In addition, the temperature inside the heating chamber is taken in as a voltage signal by the thermistor 11 to the A/D conversion terminal A/D ₀ of the microcomputer 9, and after being converted into an 8-bit digital value inside the microcomputer 9, it is stored in the RM of the microcomputer 9. The temperature is converted into a control temperature and a display temperature using a conversion table. This control temperature and the preheating set temperature are compared within the microcomputer 9, and the heater 17 is kept energized until the heating chamber temperature becomes equal to the set temperature. Heater 1
7 is in a conductive state when relays 1 and 14 are ON, relay 2.15 is ON, and relay 3.16 is OFF in the case of FIG. 4, and when the power supply to heater 17 is stopped, relay 2.15 is All you have to do is turn it off (normal state). These relays are driven via a relay driver 19. 12 is a humidity sensor, 13 is a timer volume, 1
8 is a magnetron which is a high frequency power oscillator, and selection of whether to use the heater 17 load or the high frequency power oscillator 18 load is made by switching relays 3 and 16. Now, the ROM of the microcomputer 9
The table below shows the thermistor level vs. temperature conversion table stored in .

[Table] The level values shown in Table 1 are the decimal values obtained by converting the analog signal voltage of the A/D ₀ port into 7 bits (full scale 0 to 127 levels) and digital values inside the microcontroller 9. be. To briefly explain the meaning of this table, the relay control level means that the temperature shown on the left side of the table is controlled by that level value, and the current temperature display level means that the temperature shown on the left side of the table is controlled within that level value range. It is said that the temperature is displayed. As can be seen from this table, there is a difference of two levels between the relay control level and the current temperature display start level. In other words, if the temperature in the heating chamber is actually 100°C, the current temperature display will display 100°C even though it has not yet reached 100°C. (Temperature display is performed first in the same way for other temperature values.) Although this may seem unreasonable at first glance, it is very meaningful for the following reasons. Figure 5 shows the time change in the heating chamber temperature during "oven preheating" cooking when the preheating temperature setting is 200°C. First, heater heating progresses, and the control temperature level of the thermistor 11 is set to 75 levels, which corresponds to 200℃ (Table 1
When the preheating temperature reaches _P1 , the microcomputer 9 turns on the relay 2.15 to stop the heater 17 from energizing.
Outputs a signal to turn OFF. Heater ₁ at point P
The power supply to 7 is stopped.Due to the heat capacity in the heating chamber, the temperature in the heating chamber exceeds the maximum ΔT _{by 1} degree (P ₂ points) and then begins to drop. And when the temperature drops below 200℃ (P ₃
At point), the microcomputer 9 outputs a signal to turn on the relay 2.15 in order to restart the power supply to the heater 17, indicating that the temperature in the heating chamber has fallen below the set temperature. However, due to the heat capacity in the heating chamber, the downward trend in temperature change does not stop immediately, but after going too far by ΔT ₂ degrees (P ₄ points), it begins to rise. In this way, in preheating cooking, when the heat retention operation is performed at the set temperature, there is a temperature variation of +ΔT ₁ degree and −ΔT ₂ degrees from the set temperature. The amount of overshoot varies slightly depending on the structure of the heating chamber, the mounting position of the thermistor, etc., but in most cases it is around 3°C. Also, undershoot is larger than overshoot. In preheating cooking where the temperature changes like this, if we assume that the relay control level and the current temperature display level are the same value, from point P ₃ in Figure 5,
P 10℃ lower temperature up to ₅ points, i.e. 190℃
The temperature will be displayed repeatedly, and the temperature display will repeatedly rise and fall from the set temperature level. This results in a very confusing temperature display from the user's perspective, making the user feel uneasy. Therefore, the current temperature display level is set to be shifted downward by a level corresponding to at least ΔT ₂ degrees from the relay control level. By shifting the current temperature display level below the current temperature display level and its relay control level in this manner, the inconvenience of the temperature display switching back and forth between two temperature values as described above is eliminated. However,
As shown in Figure 6, the temperature display value will first display 200°C from point P ₆ before the heating room temperature reaches 200°C, and in the case of preheating cooking, the heating room temperature will reach the set temperature. Because the temperature display shows the set temperature even though it has not yet reached the set temperature, the user is provided with false information as if cooking is complete. Trying to make it easier to read ends up confusing the user. This is an unfortunate situation. OBJECTS OF THE INVENTION In view of the above background, an object of the present invention is to realize a more continuous improvement in operational performance during oven preheating cooking. Structure of the Invention In order to achieve the above object, the heating device of the present invention has a display format different from that when preheating cooking is completed to indicate that preheating cooking is completed when the preheating set temperature is reached, so that the user can It is intended to inform the public in a more explicit manner. DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below, and the configuration of the control circuit and the like are basically the same as those of the conventional example. First, FIG. 7 shows how the display format changes when oven preheating cooking is performed. (Hereinafter, parts that are the same as those in the conventional example are given the same numbers.) When cooking starts, as shown in Fig. 7a, the display piece 6e indicating "oven" heating and the temperature display piece inside the heating chamber are different from each other as in the conventional example. Start blinking as in the example. After this, as the heating progresses and the temperature in the heating chamber rises, the temperature display piece moves to the right, and finally flashes the value of 200°C. However, Figure 7b
In this state, the temperature in the heating chamber has not yet reached 200° C., and as explained in the above-mentioned conventional example, only the display takes precedence. Therefore, heater heating continues, and the A/D conversion level of the heating chamber temperature is at the relay control level of 200°C as shown in the table.
When the level reaches 75, as shown in Figure 7 CC, display piece 6 indicates that the cooking system is "preheat".
g starts blinking. Thereafter, the display mode shown in FIG. 7c is maintained until the user opens the door or inputs the cancel key. Next, FIG. 8 shows a second embodiment in which an indicator piece 6k is provided to indicate that preheating cooking has been completed. The display until preheating cooking is completed is the same as in the conventional example in both Figures 8a and 8b, but when the temperature in the heating chamber reaches level 75, which is the relay control level of 200°C in Table 1. The "cooking complete" display piece 6k begins blinking to indicate that the series of preheating cooking has been completed, thereby clearly informing the user that the cooking process is complete. Also, the blinking cycle at this time is 700 milliseconds and 300 milliseconds.
The millisecond turn-off cycle is set to 1 second, but the timer function installed inside the microcomputer 9, which is the control unit, counts the elapsed time from the time when the preheating cooking is completed, and the blinking cycle changes according to the elapsed time. The configuration is such that the length is shortened. In other words, the light is turned on for 700 milliseconds and turned off for 300 milliseconds until 5 minutes after preheating cooking is completed.
10 minutes after 5 minutes have elapsed, the light is turned on for 350 milliseconds and turned off for 150 milliseconds, making the cycle half of the previous one. In this way, by changing the flashing cycle of the cooking completion display piece after cooking is completed, the flashing cycle can be changed over time to provide the user with a clear indication that preheating cooking has been completed. It is also possible to provide information on how much time has elapsed since the preheating temperature was reached, making it possible to provide an appliance with more detailed oven cooking performance. FIG. 9 shows an example of the processing procedure inside the microcomputer 9 regarding the display operation of the display piece indicating completion during preheating cooking. The above embodiment has been explained by flashing the cooking completion display only in the case of preheating cooking, but the cooking completion display can also be flashed for other types of cooking, such as automatic cooking using a humidity sensor. It goes without saying that by doing this, you will greatly improve your skill. Effects of the Invention As described above, according to the present invention, the completion of preheating cooking, which was unclear in the past, can be easily and clearly identified, which not only dramatically improves usability but also reduces the blinking operation cycle after completion. By changing the time, it is possible to obtain information regarding the elapsed time from the completion of cooking, thereby providing more detailed cooking performance.

[Brief explanation of drawings]

Figure 1 is a perspective view of the main body of a conventional heating device, Figure 2 is an enlarged front view of the operation panel of the same heating device, and Figure 3 is a perspective view of the main body of a conventional heating device.
Figures a and b show the display operation during preheating cooking, Figure 4 is a control circuit diagram of the heating device, and Figures 5 and 6 show temporal changes in heating chamber temperature during preheating cooking. Graphs, Figure 7 a, b, c and Figure 8 a,
b and c are explanatory diagrams of the operation of the display section of a heating device according to an embodiment of the present invention, and FIG. 9 is a flowchart of the same program. 3e... Oven preheating input key, 4... Preheating temperature setting key, 6... Display section, 6g... "Oven preheating" cooking style display piece, 6i... Cooking time display section, 6j... Temperature display section, 6k..."Cooking complete"
Display piece, 6e..."Oven" heating display piece, 9...
...Microcomputer with A/D (control unit), 11...Thermistor, 17...Electric heater, 18...Magnetron.

Claims (1)

[Scope of Claims] 1. A heating chamber in which an object to be heated is placed, a heat source for heating the object to be heated, a selection input means for oven preheating cooking, an input means for inputting a preheating set temperature for the oven preheating cooking, and the A cooking style table for preheating oven cooking, a display means for displaying a preheating temperature setting and a heating chamber temperature, a means for detecting the heating chamber temperature, a means for comparing the detected temperature with the preheating temperature setting, and a comparison means for comparing the detected temperature with the preheating temperature setting. and a control unit that controls the heating operation of the object to be heated based on the result, and is configured to blink a cooking style display piece for the oven preheating cooking when the temperature in the heating chamber reaches the preheating set temperature. heating device. 2 A patent comprising a display piece indicating that a series of heating cooking has been completed, and configured to blink the cooking completion display piece when the temperature in the heating chamber reaches the preheating set temperature during the oven preheating cooking. A heating device according to claim 1. 3. A patent claim comprising a timer means, the timer means counting the time from when the temperature in the heating chamber reaches the preheating set temperature, and changing the blinking cycle of the blinking display operation in accordance with the elapsed time. The heating device according to any one of the ranges 1 to 3.