JPH028622A - Scorching heater cooking device - Google Patents

Abstract

PURPOSE:To improve an accuracy of control for sensing a scorch by a method wherein a finder formed in a door of a heating chamber is provided with a optical absorber for absorbing a light of specified wave length radiated by a lighting means. CONSTITUTION:A side of a porous metallic plate 5 inside an outer glass plate 7 of heat-resistance glass plate forming a finder 4 arranged at a door 3 of a heating chamber 1 is coated with absorbing member 8 having a color range of orange of orange to red, absorbing lights from blue to green with a wave- length of 400mm to 550mm incident to the heating chamber 1 and having a filter function of transmitting other lights. With this arrangement, light having a wave length of 400mm to 550mm incident from an outside area reflected from a surface to a scorch sensing sensor 22 together with a scorch of the surface of a food 10 can be reduced in its influence and then a sensing accuracy of scorch can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cooking device that detects the state of browning on the surface of food and automatically controls heating to determine the browning.

Conventional technology For the browning of foods, a cooking device that automatically controls heating is disclosed in Japanese Patent Publication No. 61-27661 and Japanese Patent Publication No. 61-276.
An invention as disclosed in Japanese Patent No. 62 is known.

The invention disclosed in these publications involves irradiating the food to be heated with all visible light, and detecting the change in the intensity of reflected light from the food surface as the heating progresses, that is, the appearance of brown marks. It is detected by the original sensor, and when the degree of change reaches a predetermined value, controls such as stopping heating are performed.

Problems to be Solved by the Invention Cooking with a door that has a window that allows the food inside the heating chamber to be seen from outside the heating chamber, such as a fully electric open or a see-through viewfinder such as a gaff'F-pun. The food is stored in a container, and the food is irradiated with visible light as in the prior art described above.

The intensity of reflected light from the surface of the food changes with the occurrence of brown spots.In the case of a method that uses a sensor to detect brown spots, the illumination light from the room where the cooker is installed passes through the above-mentioned viewfinder into the heating chamber. The light enters the food and illuminates the food, superimposing it on the light detected by the sensor that detects browned food.

During the progress of browning detection controlled heating under such conditions,
To check the appearance of browning.

If you stand in front of the viewfinder and block the light from the room entering the heating chamber, the amount of light detected by the sensor that detects the browning will decrease, so the control device will detect the change in the intensity of the reflected light and detect the browning. There was a problem in that the continuation of heating was stopped when it was determined that the formation had occurred, and it was not possible to heat the burnt area with high accuracy and appropriateness. Also 1
When the brightness of the room changes (1) For example, when the brightness becomes even brighter, the problem is that heating continues even if something close to the desired browning has already been produced, resulting in excessive browning. was there. On the other hand, when the brightness becomes dark, there is a problem in that heating is stopped even though there is still insufficient browning.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a method in which the intensity of light in a specific wavelength range among the reflected light reflected from the food surface as browned marks are formed becomes remarkable. By focusing on the fact that the intensity of light reflected from the food surface varies, the aim is to ensure that the intensity of reflected light from the food surface is not affected by variations in the visible illumination source that exists outside the heating chamber.

To this end, we use a lighting device that illuminates the food in the heating chamber in a way that increases the original proportion of specific wavelengths, and we also use a burner detection source sensor that detects curls by reflection from the food surface, as described above. A device that is highly sensitive to light of a specific wavelength emitted by the lighting device is used, and the above-mentioned optical sensor in the door finder absorbs light of a wavelength to which it is sensitive and only detects other light. A light absorber is provided to allow the light to pass through.

The action lighting device emits more light at wavelengths that are highly sensitive to the sensor that detects browning.

The recognition accuracy of the degree of browning has been improved, and since the light that the browning detection source sensor is highly sensitive to does not enter the heating chamber through the finder, the browning detection source sensor can detect reflected light that changes only as browning occurs. It detects the strength accurately and accurately, and automatically controls the heating appropriately for browning.

Example An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an open range that has both a microwave oven function and an electric open function. In this diagram,
1 is the main body of the cooker, and 2 is a heating chamber. 3 is a door that opens and closes the heating chamber, and 4 is a finder. This finder 4 has a perforated metal plate 5 to prevent high frequency energy from leaking through the finder when using a microwave oven.
is provided, and heat-resistant glass plates 6 and 7 are provided on the inside and outside of the perforated metal plate 5. An original absorber 8, which will be described later, is coated on the inside of the outer glass plate 7, that is, on the side of the perforated metal plate 5 mentioned above.

9 is a turntable, and 10 is a food item to be heated. Reference numerals 11 and 12 are heating elements such as sheathed heaters, which have the ability to brown and heat the food 10 mentioned above. A hot air generator may be used instead of the sheathed heater. 13 is a magnetron which is a high frequency generation source used when heating foods with high frequency. Reference numeral 14 denotes an illumination lamp for illuminating the food. Light 15 generated by this lamp 14 enters the heating chamber through an opening 17 formed in a part of the ceiling wall 16 of the heating chamber 2 and is irradiated onto the food 10. This lamp 14 is colored syllables from blue to green on the glass surface of the rung 14 so that the proportion of light in the range of 400 nm to 550 nm is increased, and light with a wavelength of 400 + yn to 550 nm as described above is selected and irradiated. That's how it is. The reflected light 18 reflected on the surface of the food 10 passes through a small hole 20 made in the back wall 19 of the heating chamber 2, is transmitted through a light transmitting body 21 made of glass fiber, and reaches a nine-source sensor 22. 26 is a fixture for fixing the optical transmission body 22 to the back wall 19 of the heating chamber.

A control device 24 controls the operation of the heating elements 11 and 12 based on the signal from the binary sensor 22.

Now, the inside of the heat-resistant glass plate forming the finder 4, that is, the perforated metal plate side, has a color ranging from orange to red. A light absorber 8 is coated with a filter function that absorbs light from blue to green, which are complementary colors, and allows other light to pass through. The dark eye detection source sensor 22 has a peak wavelength of 440 ruy+ and a peak wavelength of 190 ruy+.
Highly sensitive to light with a wavelength of ~520 nm (iaP
Will a photodiode light receiving element be used?

Alternatively, it has high sensitivity to light with a wavelength of 190 to 680 nm (]aAfIP photodiode or 400 to 1l1
Absorbs light at wavelengths other than 400 to 550 nm in front of a light receiving element selected from a silicon photodiode with high sensitivity to light with a wavelength of 00 nm or a CdS photocell with high sensitivity to light with a wavelength of 400 to 8000 m. Provide a blue to green filter so that the

Next, the operation will be explained.

When the food 10 is stored in the heating chamber 2 of the open range configured in this way and electricity is applied to the heating elements 11.12, the temperature of the food 10 and the temperature of the heating chamber 2 rise due to the heat generated by the heating elements 11.12. do. At this time, the lighting lamp 14
is turned on to irradiate the food 10 with light having a wavelength of approximately 400 nm to 550 nm.

When the surface of the food 10 becomes burnt over time.

The original intensity of the wavelength of 400 nm to 550 ron that is reflected from the surface where the brown marks are generated and reaches the burn mark detection source sensor 22 decreases as shown in Fig. 2, and the original intensity of the original sensor 22, which had been kept constant until then, decreases. Output signal starts to drop.

A control device 24 that inputs the output signal of this original sensor 22
stores the same output value at the initial stage of heating.

The value being measured is compared with the stored value, and when there is a predetermined change in the output, that is, when a predetermined brown mark is generated and there is a predetermined change in the intensity of the reflected light, the heating element +i
, turns off the power to i2. At that time, the lighting
The source that is irradiated onto the food 10 is a source rich in blue to green colors, and the source sensor 22 that detects the reflected light from the food surface is also highly sensitive to blue to green. 10, the state of browning can be detected with high accuracy, and the finder 4 in the door is equipped with a light absorber 8 that absorbs light from blue to green, to which the original sensor 22 is highly sensitive. Since the light of the color does not enter the heating chamber, if a person who cooks approaches the finder to look into the heating chamber through the finder 4, and X'kJ enters the heating chamber from one room, it will not be able to detect browned food. The relevant wavelengths of light do not reach the heating chamber through the finder.

Heating can be performed to a predetermined browning level without affecting the intensity of the reflected light detected by the original sensor 22 and without reducing the browning detection accuracy. Also, even if the lighting conditions in the room change during cooking and the amount of light entering the heating chamber changes, it will not affect the reflected light detected by the browning detection source sensor 22. Highly accurate automatic control can be achieved.

Effects of the Invention According to the present invention, highly accurate browning detection control can be realized, and an excellent automatic cooking device that is not affected by the lighting of the room in which the cooking device is installed can be realized.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an open range that is an example.
FIG. 2 is a diagram illustrating how the reflectance of a specific wavelength in reflected light changes. 2...Heating chamber, 3...Door. 4...Finder, 10...Food. 11.12... Heating element, 14... Illumination lamp. 22... Burnt detection source sensor, 24... Control device.

Claims (4)

[Claims] (1) A heating chamber (2) that stores food (10) and a heat generating device (11) that heats the food until browned.
, (12); illumination means (14) for irradiating the food with a source of a specific wavelength; and illumination means (14) for illuminating the food and detecting reflected light reflected from the surface of the food. Light receiving sensor (2) that is highly sensitive to light
2), a control device (24) that controls the heat generating device based on the signal of the light receiving sensor, a door (3) that opens and closes the heating chamber, and a finder (3) formed on this door.
4) and a browning cooking device characterized in that the finder is provided with a light absorber (8) that absorbs light of a specific wavelength irradiated by the illumination means. (2) The browning cooking device according to claim 1, wherein the light having a specific wavelength is blue to green light having a wavelength of approximately 400 nm to 550 nm. (3) According to claim 1, the finder is made of two heat-resistant transparent plates, and the single light absorber is formed on the inner surface sandwiched between the heat-resistant transparent plates. Added heating cooker. (4) The browning cooking device according to claim 1, wherein the finder provided with the light absorber is a colored heat-resistant semi-transparent plate.