JPH01314825A - Heat cooking apparatus with scorching function - Google Patents

Abstract

PURPOSE:To automatically cook without being affected by a light in a room by absorbing the wavelength to be sensed by an optical sensor for selectively photodetecting a scorching color of visible light rays incident from a window by the door window. CONSTITUTION:Part of a visible light to be radiated from an illumination lamp 7 is radiated to and reflected on food 3 to arrive at a photodetecting sensor 9 from a photodetecting window 8a. Blue to green colors of the radiated light are mainly absorbed if the good is scorched. On the other hand, blue to green filters are, for example, provided at the sensor 9 so that, if the food 3 is scorched, the output signal of the sensor 9 is reduced. The comparison value of the output value at the time of good finish to that at a predetermined time is predetermined, a controller 10 is operated when it arrives at the comparison value to turn OFF the power source of heat generators 6, 6'. A heat preventive glass plate 5b or an outer window plate 5c mounted at a door window 5 absorbs blue to green color wavelengths of the visible light, and the sensor 9 is not hence affected by the external light.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to cooking appliances such as oven ranges, toasters, and electric ovens that can automatically cook food by heating food and detecting the brown color on the surface of the food.

Conventional technology To cook food to a completely browned color, a heating element is installed at the top, bottom or back of the oven, and the temperature is raised by radiant heat or hot air from the heating element to completely cook the food inside the oven. ing. This type of cooking appliance is typified by an oven range, an electric oven, a toaster, etc., and heating is controlled by a temperature controller and a timer.

In addition, as a device that performs all automatic cooking, the special public
As shown in Publications No. 661 and No. 61-27662.

The food is irradiated with all visible light, and the illuminance of the reflected light from the food is detected and stored at a certain point in the initial stage of heating using an optical sensor, and then the illuminance of the reflected light changes as the heating progresses. A heat addition device using a brown color detection controller has been proposed which performs full detection, compares both detection results, and performs full heating control when a predetermined difference occurs.

Problems to be Solved by the Invention Since there is a limit to the ability to change the heating conditions depending on the amount of food, moisture content, composition, etc. using a temperature controller or timer, skill is required to achieve the desired browning color.9
There are drawbacks such as over-heating or under-heating due to inappropriate settings. There is also an automatic method that detects changes in visible light reflected light illuminance.

The front of the cooking appliance is equipped with a door for loading and unloading food and a window with good light transmission so that you can observe the inside of the refrigerator. Therefore, the light from one room enters through the window of the cooking appliance door. Also, the flavor may change as it bakes.

The optical sensor cannot tell whether it is a change in the incident light or a change in the browned color of the food, resulting in malfunctions and often resulting in poor cooking. It has its drawbacks.

Means for Solving All Problems In order to solve all of these drawbacks, the present invention provides a light sensor that selectively receives the browned color of 9 foods out of the visible light reflected from 9 foods, and a window on the door of a cooking utensil. The method is to install a window that absorbs visible light other than the specific wavelength of the light sensor and allows it to pass into the oven.

1 of the visible rays that enter through the window of the door of the cooking utensil
The door window absorbs the light at the wavelength that the optical sensor, which selectively detects browned food, detects, so it is not detected by the sensor. Other wavelengths of light enter through the door window, but this does not pose a problem because the sensitivity of the sensor is low.

Embodiment One embodiment of the present invention will be explained based on the drawings. FIG. 1 is a sectional view of a microwave oven. Among the main components, 1
is an oven, 2 is a saucer, 3 is food, 4 is a door, 5 is a door window, 6, 6° is a heating element, 7 is an illumination lamp, 8 is a light transmitter, and 9 is a light receiving sensor.

10 is a control device, 11 is a magnetron, and 12 is a waveguide.

The door window 5 for viewing the inside of the oven chamber 1 includes a screen plate 5a and a heat-insulating glass plate 5 to prevent leakage of high-frequency radio waves.
b and an outer window panel 5C for heat insulation. The heat-insulating glass plate 5b or the outer window plate 5C has all colors of orange to red, and has a characteristic of easily absorbing blue to green light, which are complementary colors of white light.

The light receiving sensor 9 has a peak wavelength of 440.

A GaP photodiode light receiving element that can detect all wavelengths from 190 to 520 nm is used, or a GaAsP photodiode or a GaAsP photodiode having a wavelength sensitivity of 190 to 680 nm is used.
Silicon photodiode with wavelength sensitivity of 0~1100u, Gas with wavelength sensitivity of 400~800''-
400 to 55 in front of the light receiving element selected from photocell' etc.
Provide a blue to green filter to absorb light other than 〇-.

Alternatively, an optical rod made of blue to green heat-resistant glass or a heat-resistant resin optical rod is attached to the entire light-receiving window 8a in front of the light transmitting body 8. In this case, the aforementioned GaAsP photodiode, silicon photodiode, Cds photocell, or the like is used as the light receiving element. The illumination lamp 7 that illuminates the inside of the oven includes a tungsten lamp or a lamp whose surface glass is colored blue to green so as to emit a large amount of light of 400 to 550 m2.

The heating element is equipped with a sheathed heater with good radiation, a heat-resistant glass tube heater, a planar heater, a halogen lamp heater, a quartz lamp heater, or a fan to generate hot air.

The control device 10 converts the output signal from the light receiving sensor 9 into an analog voltage, performs AD conversion, and captures it as a digital signal. As an output signal, the state at a certain point in the initial stage of heating is memorized in all microcontrollers.

The output value that changes with the elapse of heating time is compared with the above-mentioned stored value. As a result of the comparison, when the difference value reaches a certain value, the microcomputer operates a relay to turn off the power to the heating element 6.6.

FIG. 2 shows a ratio of light reflection when the food 3 has been heated to a brown color and before heating.

This is an actual measurement of the amount of reflected light after grilling all the sliced bread, but when the bread is burnt, the amount of reflected light is 4.
It decreases in the wavelength range of 00 to 600 m.

This shows that it absorbs white light from blue to green.

Food 3 is placed in the microwave oven configured as described above and the power is turned on. The temperature inside the oven 1 rises due to the radiant heat from the heating elements 6 and 6I.

When cooking in the oven, maintain a constant temperature. Depending on the purpose of cooking, microwave heating may be used together with the magnetron 11''.The temperature of the food 6 rises and after a certain period of time, the surface of the food 1 becomes burnt. The visible light illuminates the inside of the oven compartment 1, but a part of the visible light hits the food product B and is reflected and is reflected by the light receiving window 8.
From a, the entire diameter of the light transmitting body 8 reaches the light receiving sensor 9. The amount of reflected light from the food temporarily increases from the early to middle stages of heating, and then gradually decreases as the heating time progresses as the food begins to burn. When food burns, reflected light mainly absorbs blue to green colors. Since the light-receiving sensor 9 is selectively sensitive to blue to green, when one food item 5 burns, the output signal of the light-receiving sensor 9 decreases. Therefore, a comparison value between the output value at a good finish and the output value at a constant time is determined in advance, and when the comparison value is reached, the control device 10 is activated and the power to the heating element 6.6I is turned off. be.

Here, the illuminance inside the oven chamber 1 increases because, in addition to the illumination lamp 7, light from the room enters from the door window 5 of the cooking utensil. However, among the incident visible light, light with wavelengths from blue to green is absorbed and removed by the orange to red heat-insulating glass plate 5b or outer window plate 5C installed inside and outside the screen plate 5a. , the light receiving sensor 9 is not affected by ambient light, and automatic cooking can be performed without malfunction.

Effects of the Invention As described above, in the present invention, when the light from the lamp that illuminates the entire interior of the heating cooking appliance hits the food and is reflected and the food is heated and burnt, visible light from blue to green is selectively absorbed. As a result, the amount of reflected light decreases, but the degree of this decrease can be accurately detected by using a light receiving sensor that selectively detects the edges from blue. By using a window as a light transmitting body with a filtering effect in colors ranging from orange to red that easily absorbs blue to green, it is possible to provide an excellent automatic cooking appliance that is not affected by light entering the room. .

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a microwave oven which is an embodiment. FIG. 2 is a diagram completely explaining how the reflection ratio of a specific wavelength changes in reflected light. 1... Oven storage, 3... Food. 5... Door window, 7... Lighting lamp. 9...Light receiving sensor.

Claims (1)

[Claims] A heat generating device (6) for browning and heating the object to be heated (3) in the oven chamber (1), and a window (5) such as a glass window so that the inside of the oven chamber can be visually observed from outside the oven chamber.
) and a door provided with a transparent material in the window that absorbs light between blue and green and transmits light of other wavelengths, and a door that transmits visible light containing light of wavelengths between blue and green to the heated object. An illumination lamp (7) for illuminating the object, and a light receiving sensor (7) for highly sensitively detecting light with a wavelength between blue and green among the reflected light irradiated by the illumination lamp and reflected from the surface of the heated object.
9) and a control device (10) that controls the heat generating device based on the signal from the light receiving sensor.