EP3438544A1

EP3438544A1 - Cooking device

Info

Publication number: EP3438544A1
Application number: EP17774855.5A
Authority: EP
Inventors: Ryuta Kondo; Masafumi Sadahira; Hideki Nakamura
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2016-03-29
Filing date: 2017-03-27
Publication date: 2019-02-06
Also published as: WO2017170318A1; JPWO2017170318A1; EP3438544A4; CN109073231A

Abstract

Provided is a cooking device including: image capturing unit (23) that captures an image of an inside of heating chamber (13) for accommodating food (12); and lighting level controller (33) that changes a lighting level provided by lightings (25a to 25d) for illuminating the inside of heating chamber (13).

Description

TECHNICAL FIELD

The present disclosure relates to a cooking device that cooks food and the like.

BACKGROUND ART

Some conventional cooking devices including a heating chamber are provided with an image capturing unit that captures an image of an inside of the heating chamber such that a condition of food which is an object to be heated can be checked (see, for example, PTL 1). In the conventional cooking device described above, a degree of scorching of food, which is a food condition during cooking, is recognized and checked through image processing based on an image captured by the image capturing unit.
In the above-mentioned conventional cooking device provided with the image capturing unit, it is inevitable that food in the heating chamber surrounded by wall surfaces and a lighting are close to each other. Therefore, light emitted from a light source is locally too strong, and thus, a color of food detected by the image capturing unit may be whiter than the true color of the food, or a dark shadow may be generated on a rear surface side of the food in the heating chamber as viewed from the light source. When at least one of local high illuminance and shadow occurs, a scorched color cannot be accurately detected.
Conventionally, in a cooking device of this type, food is generally heated while being placed on a placement tool such as tableware or a parchment paper in the heating chamber. In this case, to separate the food from the placement tool, such as tableware, which becomes a nearby background other than the food, in an image, edge tracking is performed to determine an area of the food.
However, when local high illuminance or shadow occurs due to an effect of the lighting, the food condition cannot be accurately detected and is erroneously detected. Besides, an edge is absent from the captured image, and therefore, the edge cannot be extracted. Thus, the area of the food cannot be detected.
In addition, if the food and the nearby background around the food have a similar color, it is difficult to separate the food from the background to accurately detect the food. Moreover, if the illuminance provided by the lighting is high with the brightness of the food and the nearby background being high and whitish, it is more difficult to identify the food.

Citation List

Patent Literature

PTL 1: Unexamined Japanese Patent Publication No. 2001-272045

SUMMARY OF THE INVENTION

The present disclosure is accomplished in view of the foregoing conventional problem, and aims to provide a cooking device including an image capturing unit and a lighting unit, the cooking device making it easy to separate an object to be heated, such as food, from a background and to specify an image of the object to be heated, that is, to accurately detect the object to be heated and identify a contour of the object to be heated, in order to recognize a condition of the object to be heated.
Specifically, a cooking device according to one exemplary embodiment of the present disclosure includes: an image capturing unit that captures an image of an inside of a heating chamber; a lighting unit that emits light to the inside of the heating chamber; a lighting level controller that changes a lighting level provided by the lighting unit; and an image processor that specifies an image of the object to be heated in the image captured by the image capturing unit.
With this configuration, a plurality of images having different lighting levels from one another by the lighting level controller can be captured. Thus, even if the object to be heated and a background near the object to be heated have a similar color, the object to be heated can be captured with a lighting level being set such that a color difference between the object to be heated and the background can be distinguished in many tones.
Further, a comparison of the plurality of images having different lighting levels in the image processor shows that, when the lighting level is changed, a position of the object to be heated in the image is unchanged, whereas a position of at least one of local high illuminance and shadow generated in the image is changed. Therefore, through detection of the changes, the object to be heated can be separated from the background.
As described above, according to the cooking device in the exemplary embodiment of the present disclosure, the object to be heated can be captured with the lighting level being changed by the lighting level controller. Accordingly, it becomes easy, in the image processor, to separate the object to be heated from the background and to specify an image of the object to be heated, that is, to accurately detect the object to be heated and identify the contour of the object to be heated. Thus, the condition of the object to be heated can be accurately detected.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing a schematic configuration of a main part of a cooking device according to a first exemplary embodiment of the present disclosure.
FIG. 2A is a view showing a schematic configuration of another lighting pattern of the cooking device according to the first exemplary embodiment of the present disclosure.
FIG. 2B is a view showing a schematic configuration of still another lighting pattern of the cooking device according to the first exemplary embodiment of the present disclosure.
FIG. 3 is a view showing a schematic configuration of a main part of a cooking device according to a second exemplary embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

A cooking device according to one exemplary embodiment of the present disclosure includes: a heating chamber that houses an object to be heated; an image capturing unit that captures an image of an inside of the heating chamber; a lighting unit that emits light to the inside of the heating chamber; a lighting level controller that changes a lighting level provided by the lighting unit; and an image processor that specifies an image of the object to be heated in the image captured by the image capturing unit.
With this configuration, a plurality of images having different lighting levels from one another by the lighting level controller can be captured. Thus, even if food that is the object to be heated and a background near the object to be heated (nearby background) have a similar color, the object to be heated can be captured with a lighting level being set such that a color difference between the object to be heated and the nearby background can be distinguished in many tones.
Further, a comparison of the plurality of images having different lighting levels in the image processor shows that, when the lighting level is changed, a position of the object to be heated in the image is unchanged, whereas a position of at least one of local high illuminance and shadow generated in the image is changed. Therefore, through detection of the changes, the object to be heated can be separated from the background.
Specifically, with this configuration, a plurality of images having different lighting levels from one another by the lighting level controller can be captured. Thus, even if the object to be heated and the nearby background have a similar color, the object to be heated can be captured with a lighting level being set such that a color difference between the object to be heated and the nearby background can be distinguished in many tones. Accordingly, it becomes easy, in the image processor, to separate the object to be heated from the background and to specify an image of the object to be heated, that is, to accurately detect the object to be heated and identify the contour of the object to be heated.
Further, the cooking device according to one exemplary embodiment of the present disclosure may include a lighting pattern storage unit that stores a plurality of lighting patterns. In this case, the lighting unit may be configured to emit light based on the plurality of lighting patterns. Further, in this case, in the cooking device according to one exemplary embodiment of the present disclosure, the lighting level controller may be configured to cause the lighting unit to execute at least two of the plurality of lighting patterns.
With this configuration, a plurality of images having different lighting levels from one another (a plurality of images captured with different lighting levels) can be captured using the plurality of lighting patterns stored in the lighting pattern storage unit. Accordingly, a comparison of the plurality of images having different lighting levels in the image processor shows that, when the lighting level is changed, a position of the object to be heated in the image is unchanged, whereas a position of at least one of local high illuminance and shadow generated in the captured image is changed. Therefore, through detection of the changes, the object to be heated can be separated from the background. Thus, the object to be heated can be accurately detected.
Further, in the cooking device according to one exemplary embodiment of the present disclosure, the lighting level controller may be configured to change the lighting level provided by the lighting unit according to brightness of the image captured by the image capturing unit.
With this configuration, when the object to be heated and the nearby background have a similar color with high brightness, the illuminance provided by the lighting unit is reduced. With this configuration, a portion with low brightness other than the object to be heated and the nearby background in the image becomes solid in a dark color. On the other hand, the object to be heated and the nearby background which have a color with high brightness can be captured such that the color difference between them can be distinguished in many tones. Accordingly, it becomes easy, in the image processor, to separate the object to be heated from the background and to specify an image of the object to be heated, that is, to accurately detect the object to be heated and identify the contour of the object to be heated.
On the contrary, when the object to be heated and the nearby background have a similar color with low brightness, the illuminance provided by the lighting unit is increased. With this configuration, halation occurs in a portion with high brightness other than the object to be heated and the nearby background in the image. Meanwhile, the object to be heated and the nearby background which have a color with low brightness are captured such that the color difference between them can be distinguished in many tones. Accordingly, as in the former case, it becomes easy, in the image processor, to separate the object to be heated from the background and accurately detect the object to be heated.
The cooking device according to one exemplary embodiment of the present disclosure may include a plurality of lighting units. In this case, in the cooking device according to one exemplary embodiment of the present disclosure, the lighting level controller may be configured to change the lighting level by controlling on and off of the plurality of lighting units.
With this configuration, a number of lighting units to be turned on is changed, by which the illuminance in the heating chamber is changed. As a result, a plurality of images having different illuminances can be captured. Accordingly, even if the object to be heated and the nearby background have a similar color, the object to be heated can be captured with a lighting level being set such that a color difference between the object to be heated and the nearby background can be distinguished in many tones. Accordingly, it becomes easy, in the image processor, to separate the object to be heated from the background and accurately detect the object to be heated.
Further, due to the lighting unit to be turned on being switched, a plurality of images having different lighting levels can be captured. Accordingly, a comparison of the plurality of images having different lighting levels shows that, when the lighting unit to be turned on is switched, a position of the object to be heated in the image is unchanged, whereas a position of at least one of local high illuminance and shadow generated in the captured image is changed. Thus, the background can be detected and separated from the object to be heated, whereby the object to be heated can be accurately detected.
In addition, the cooking device according to one exemplary embodiment of the present disclosure may include a plurality of the lighting units. In this case, the plurality of lighting units may be disposed on at least one of a wall surface and a top surface of the heating chamber. Moreover, in this case, the plurality of lighting units may have at least one combination of lighting units which are distant from each other across the image capturing unit at 30 degrees or more based on the center of the heating chamber in a plan view of the heating chamber as viewed from top.
With this configuration, if the combination of the lighting units distant from each other at 30 degrees or more in a plan view of the heating chamber as viewed from top is used in the control for switching the lighting unit to be turned on, the position of at least one of local high illuminance and shadow generated in the image can be changed according to the installation angles of the lighting units. Therefore, a comparison of the plurality of images shows that the position of at least one of the high illuminance portion and shadow is greatly changed. Accordingly, it becomes easier to detect the change and separate the object to be heated from the background, whereby the object to be heated can be accurately detected.
Further, in the cooking device according to one exemplary embodiment of the present disclosure, the lighting unit may be configured to illuminate with a plurality of luminance values. In this case, the lighting level controller may be configured to change the lighting level by switching the plurality of luminance values of the lighting unit.
With this configuration, the illuminance in the heating chamber can be changed by switching the plurality of luminance values of the lighting unit, whereby a plurality of images having different illuminances can be captured. Therefore, even if the object to be heated and the nearby background have a similar color, the object to be heated can be captured with a lighting level being set such that a color difference between the object to be heated and the nearby background can be distinguished in many tones. Accordingly, it becomes easy, in the image processor, to separate the object to be heated from the background and accurately detect the object to be heated.
Further, in the cooking device according to one exemplary embodiment of the present disclosure, the image capturing unit may be configured to capture an image of the inside of the heating chamber through a through-hole or a transparent member formed in at least one of a wall surface and a top surface of the heating chamber.
With this configuration, the image capturing unit can be disposed on an outer side of the heating chamber, whereby unnecessary reflection and shadow of illumination light in the heating chamber by the image capturing unit can be prevented. In addition, this configuration can prevent the image capturing unit from interfering with the heating of the object to be heated in the heating chamber, and can easily address a temperature problem of the image capturing unit. Accordingly, malfunction of the image capturing unit due to a high temperature in the heating chamber can be prevented.
Exemplary embodiments of the present disclosure will be described below with reference to the drawings.
The present disclosure is not limited to a configuration of a cooking device described in the following exemplary embodiments.

(First exemplary embodiment)

FIG. 1 is a view showing a schematic configuration of a main part of a cooking device according to a first exemplary embodiment of the present disclosure. FIG. 2A is a view showing a schematic configuration of another lighting pattern of the cooking device according to the first exemplary embodiment of the present disclosure. FIG. 2B is a view showing a schematic configuration of still another lighting pattern of the cooking device according to the first exemplary embodiment of the present disclosure.
As shown in FIGS. 1, 2A, and 2B, cooking device 11 according to the first exemplary embodiment of the present disclosure includes heating chamber 13 that houses food 12 which is an object to be heated. Cooking device 11 is configured to cook the object to be heated with a heating source (not illustrated) such as a heater, a magnetron, or a steam generator.
Heating chamber 13 has top surface 17, left wall surface 18, rear surface 19, right wall surface 20, and bottom surface 21 which are wall surfaces, and a door (not illustrated). In the present exemplary embodiment, heating chamber 13 has a substantially cuboid shape. Top surface 17, left wall surface 18, rear surface 19, and right wall surface 20 are formed from, for example, a material such as enamel steel sheet, a stainless steel sheet, or a coated steel sheet. In the present exemplary embodiment, heating chamber 13 has a width of 400 mm and a depth of 300 mm.
Inclined surface 22 is formed between top surface 17 and left wall surface 18 of heating chamber 13. Inclined surface 22 is formed by drawing press, for example, and provided at a middle part of heating chamber 13 in the depth direction between top surface 17 and left wall surface 18. That is, inclined surface 22 is locally formed to extend in the depth direction with a position 150 mm away from rear surface 19 being defined as substantially a center, for example.
Image capturing unit 23 is provided on an outer side (opposite to an inner side of heating chamber 13) of inclined surface 22. Specifically, image capturing unit 23 is fixed to heating chamber 13 so as to be displaced in a direction (along a normal of inclined surface 22 toward the outside of heating chamber 13 (in FIG. 1, in an upper left direction)) in which image capturing unit 23 is away from the inside of heating chamber 13 further from inclined surface 22. Image capturing unit 23 is also configured to be capable of capturing an image of an inside of heating chamber 13 through through-hole 24 formed in inclined surface 22. An imaging center of image capturing unit 23 is directed downward at an angle of 30 degrees, for example, in relation to the horizontal direction such that food 12 mainly falls within the field of view. The imaging center of image capturing unit 23 may be directed downward at an angle of 0 degrees to about 50 degrees in relation to the horizontal direction, according to an angle of view of image capturing unit 23. When the angle of inclined surface 22 is set such that inclined surface 22 is perpendicular to a direction of the imaging center of image capturing unit 23, image capturing unit 23 is easily fixed.
Lightings 25a, 25b, 25c, and 25d serving as a plurality of lighting units include a light emitting diode (LED), for example. In the present exemplary embodiment, lightings 25a, 25b, 25c, and 25d are respectively provided near four corners of top surface 17 of heating chamber 13, that is, at front sides and rear sides of upper parts of left and right wall surfaces 18 and 20 (see FIG. 1). In the present exemplary embodiment, lighting 25a is provided at the front side of left wall surface 18, lighting 25b is provided near rear surface 19 at the rear side of left wall surface 18, lighting 25c is provided near rear surface 19 at the rear side of right wall surface 20, and lighting 25d is provided at the front side of right wall surface 20. Lightings 25a to 25d are configured to be capable of emitting light toward the inside of heating chamber 13 from LEDs provided on an outer surface side of the wall surfaces.
Further, in cooking device 11 according to the present exemplary embodiment, light source centers of lightings 25a and 25d are disposed respectively on left and right wall surfaces 18 and 20 at positions 250 mm away from rear surface 19 to the front. Light source centers of lightings 25b and 25c are disposed respectively on left and right wall surfaces 18 and 20 at positions 50 mm away from rear surface 19 to the front. Accordingly, in cooking device 11 in the present exemplary embodiment, lightings 25a and 25b are distant from each other in such a way that an angle between each of lightings 25a and 25b and a straight line connecting the center of the bottom surface of heating chamber 13 and image capturing unit 23 is about 26.5 degrees in a plan view of heating chamber 13 as viewed from top. That is, two lightings 25a and 25b are distant from each other at an angle of about 53 degrees based on the center of the bottom surface of heating chamber 13. Similarly, lightings 25c and 25d are distant from each other at an angle of about 53 degrees based on the center of the bottom surface of heating chamber 13.
Controller 31 of cooking device 11 is configured with a microcomputer (not illustrated) that includes, for example, a central processing unit (CPU), a memory, and an input and output interface. Controller 31 includes inside image processor 32, lighting level controller 33, and lighting pattern storage unit (storage unit) 34. Image processor 32 is electrically connected to image capturing unit 23, and performs a process for specifying an image of food 12 in image data of the inside of heating chamber 13 which has been captured and acquired by image capturing unit 23. Lighting level controller 33 is electrically connected to lightings 25a to 25d, and changes lighting levels provided by lightings 25a to 25d based on lighting pattern data stored in lighting pattern storage unit 34.
The operation and effect of cooking device 11 having the above-mentioned configuration will be described below.
Food 12 placed on tableware 35 which is a placement tool is put into heating chamber 13 of cooking device 11 by a user. The inside of heating chamber 13 is illuminated with lightings 25a to 25d, and therefore, illuminance enough to ensure visibility for image capturing unit 23 can be provided. In cooking device 11 according to the present exemplary embodiment, four lightings 25a to 25d are all turned on as a first pattern stored in lighting pattern storage unit 34, as illustrated in FIG. 1.
While cooking device 11 is operated, a cooking condition of food 12 is recognized and checked in cooking device 11 as well as the inside of heating chamber 13 is captured by image capturing unit 23 and the captured image is displayed. In this case, if food 12 and tableware 35 both have a similar whitish color with high brightness, illumination light emitted from lightings 25a to 25d is reflected on food 12 and tableware 35, so that the illuminance inside heating chamber 13 increases. Besides, the distance between food 12 and each of lightings 25a to 25d provided on left and right wall surfaces 18 and 20 is generally about 100 mm to 500 mm in this type of the cooking device, that is, the light source and food 12 are close to each other. Therefore, light emitted from lightings 25a to 25d is too strong, resulting in that the brightness of food 12 to be detected by image capturing unit 23 is significantly increased. Accordingly, an amount of detected light exceeds a range and a portion recognized to be white may be generated.
However, cooking device 11 in the present exemplary embodiment has lighting level controller 33 that can change the lighting level, and thus, as shown in FIG. 2A, only two lightings that are front left lighting 25a and rear right lighting 25c are turned on as a second pattern stored in lighting pattern storage unit 34. With this configuration, the illuminance in heating chamber 13 is substantially halved. Thus, the brightness of the image captured by image capturing unit 23 is reduced as a whole, which can prevent the amount of detected light from exceeding the range in a color tone with higher brightness, while a background image portion with low brightness other than food 12 and tableware 35 becomes solid in a dark color. Thus, similar whitish colors with higher brightness can be detected and captured in many tones by image capturing unit 23, whereby tones can be appropriately distinguished by image processor 32.
Therefore, even if food 12 and tableware 35 both have a similar whitish color with high brightness, an image in which the color of food 12 and the color of tableware 35 can be distinguished as different colors can be captured. Thus, image processor 32 can easily separate food 12 from tableware 35 that is a nearby background and specify the image of food 12. That is, image processor 32 can easily detect food 12 with high accuracy and identify the contour of food 12.
When only two lightings that are front left lighting 25a and rear right lighting 25c are turned on, shadow 36a of food 12 is generated by lighting 25a, and shadow 36c is generated by lighting 25c on the opposite side across food 12.
Then, as shown in FIG. 2B, lighting level controller 33 changes the lighting level by turning on only two lightings that are rear left lighting 25b and front right lighting 25d as a third pattern stored in lighting pattern storage unit 34. With this configuration, a position of local high illuminance generated in the image captured by image capturing unit 23 is changed. Accordingly, image processor 32 can distinguish a contour whose position is changed from a contour whose position is unchanged according to the lighting patterns through a comparison of images captured in the first pattern, the second pattern, and the third pattern stored in lighting pattern storage unit 34, determine the contour whose position is changed to be a local high illuminance portion, and separate the determined portion. Thus, image processor 32 can accurately detect food 12.
In this case, shadow 36b of food 12 is generated by lighting 25b, and shadow 36d is generated by lighting 25d on the opposite side across food 12. Shadow 36b and shadow 36a generated in the second pattern are generated so as to be distant from each other at an angle determined by the installation angles of lightings 25a and 25b. For example, in the above example in the present exemplary embodiment, lightings 25a and 25b are distant from each other at approximately 53 degrees. Therefore, if food 12 is placed at the center of heating chamber 13, shadow 36b and shadow 36a in the second pattern are generated to be distant from each other at approximately 53 degrees according to the installation angles of lightings 25a and 25b. Similarly, shadow 36d and shadow 36b in the second pattern are generated to be distant from each other at approximately 53 degrees. Therefore, when shadows 36a and 36c generated by the lightings which are turned on in the second pattern and shadows 36b and 36d generated by the lightings which are turned on in the third pattern are compared, it is found that positions of shadows captured by image capturing unit 23 vary greatly.
In this way, if the combination of the lighting units (lightings 25a to 25d) distant from each other at 30 degrees or more in a plan view of heating chamber 13 as viewed from top is used, the position of at least one of local high illuminance and shadow generated in the image can be changed according to the installation angles of the lightings 25a to 25d which are the lighting units. With this configuration, through a comparison of a plurality of images, it is found that the position of at least one of high illuminance and shadow is greatly changed, and thus, image processor 32 can more easily separate food 12 from tableware 35 through detection of the change, thereby being capable of accurately detecting food 12.
On the other hand, when only two lightings are turned on as in the second pattern and the third pattern in lighting pattern storage unit 34 as shown in FIGS. 2A and 2B in the case where food 12 and tableware 35 both have a similar dark color with low brightness, illumination light emitted from the lighting units is less reflected on food 12 and tableware 35, and therefore, the illuminance in heating chamber 13 becomes low.
However, cooking device 11 according to the present exemplary embodiment includes lighting level controller 33 that can change the lighting level. In cooking device 11 according to the present exemplary embodiment, when four lightings which are lightings 25a to 25d are turned on as the first pattern stored in lighting pattern storage unit 34 shown in FIG. 1, the illuminance in heating chamber 13 increases, whereby deficiency in the amount of detected light in colors of low brightness can be prevented. On the other hand, halation occurs in the background image portion with high brightness other than food 12 and tableware 35. Thus, similar dark colors which are colors with lower brightness can be detected and captured in many tones by image capturing unit 23. Therefore, tones can be appropriately distinguished by image processor 32.
As described above, the lighting level is changed by lighting level controller 33 according to the brightness of the captured image. With this configuration, when food 12 and the background near food 12 have a similar color with high brightness, the illuminance provided by lightings 25a to 25d is reduced, whereby the color difference between food 12 and the background near food 12 can be captured in many tones. Thus, image processor 32 can easily separate food 12 which is the object to be heated from the background and specify the image of food 12. That is, image processor 32 can easily detect food 12 with high accuracy and identify the contour of food 12.
On the contrary, when food 12 and the background near food 12 have a similar color with low brightness, the illuminance provided by lightings 25a to 25d is increased, whereby the color difference between food 12 and the background near food 12 can be captured in many tones. Accordingly, as in the former case, image processor 32 can easily separate food 12 from the background and detect food 12 with high accuracy.
Further, the number of lighting units (lightings 25a to 25d) to be turned on is changed by controlling on and off of lightings 25a to 25d which are a plurality of lighting units as described above. With this configuration, the lighting level can be changed, and thus, the illuminance in heating chamber 13 is changed. Accordingly, a plurality of images having different illuminances can be captured. Thus, even if food 12 and the nearby background have a similar color, food 12 which is the object to be heated can be captured with a lighting level being set such that a color difference between food 12 and the background can be distinguished in many tones. Accordingly, image processor 32 can easily separate food 12 from the background and detect food 12 with high accuracy.
Further, due to the lighting unit (lightings 25a to 25d) to be turned on being switched, a plurality of images having different lighting levels can be captured. Therefore, a comparison of the plurality of images shows that, when the lighting unit to be turned on is switched, a position of food 12 in the plurality of images is unchanged, whereas a position of at least one of local high illuminance and shadow generated in the plurality of images is changed. Accordingly, image processor 32 can separate food 12 from the background through detection of the positional change, thereby being capable of accurately detecting food 12.
Notably, the method for changing the lighting level is not limited to the method for changing the number of lighting units (lightings 25a to 25d) to be turned on by controlling on and off of lightings 25a to 25d which are the plurality of lighting units. For example, the lighting level may be changed by increasing or decreasing the luminance of lighting provided by lightings 25a to 25d which are the plurality of lighting units.
When the contour of food 12 can be identified as described above, a burnt color of food 12 which is the cooking condition of food 12 can be further easily recognized by image processor 32. Specifically, baking of cookies will be given as an example. Cooking doughs (not shown) are arranged on a white parchment paper placed on an iron tray, and put into heating chamber 13. In this case, the contour of the cookie which is food 12 can be distinguished from the parchment paper which is the background, and accurately detected by image processor 32.
Then, the temperature inside heating chamber 13 is set to 170°C, for example, and the baking is started. The whitish cookie doughs turn into brown at about ten minutes after the start of the baking, whereas the parchment paper remains white. At that time, image processor 32 accurately recognizes the contour of the cookie doughs, that is, food 12. Therefore, it can be prevented that image processor 32 falsely recognizes that the cookie doughs have not yet turned into brown through detection of the white part of the parchment paper.
When food 12 which is the object to be heated is captured by image capturing unit 23 during cooking as described above, the temperature in heating chamber 13 is very high (such as 170°C as described above), and significantly exceeds a heat proof temperature (for example, 70°C) of image capturing unit 23. However, in cooking device 11 according to the present exemplary embodiment, through-hole 24 for image capturing unit 23 is formed in inclined surface 22 forming the wall surface of heating chamber 13 as described above. Further, in cooking device 11 in the present exemplary embodiment, image capturing unit 23 is provided on an outer side of inclined surface 22 (opposite side from an internal side of heating chamber 13), and configured to capture the image of the inside of heating chamber 13 through through-hole 24.
With this configuration, the problem of image capturing unit 23 involved with a temperature can be easily addressed, and therefore, malfunction of image capturing unit 23 due to a high temperature can be prevented. Further, image capturing unit 23 is provided on an outer side of heating chamber 13, whereby at least one of unnecessary reflection and shadow of illumination light in heating chamber 13 by image capturing unit 23 can be prevented. In addition, it can be prevented that image capturing unit 23 interferes with heating of food in heating chamber 13.
The present exemplary embodiment shows the configuration in which, in cooking device 11, image capturing unit 23 is provided on an outer side of inclined surface 22 between top surface 17 and left wall surface 18. However, a through-hole may be formed in left wall surface 18 without providing inclined surface 22. In addition, cooking device 11 according to the present exemplary embodiment may be configured such that the inclined surface is formed between top surface 17 and right wall surface 20 or between top surface 17 and rear surface 19, a through-hole is formed in the inclined surface, and image capturing unit 23 is provided.
Further, cooking device 11 in the present exemplary embodiment may be configured such that, if there is no component which becomes an obstacle at the outside of top surface 17, a through-hole is formed in top surface 17, and image capturing unit 23 is provided outside of the through-hole. Alternatively, in cooking device 11 in the present exemplary embodiment, a transparent member such as transparent glass may be provided on the front door of heating chamber 13, and image capturing unit 23 may be disposed to capture an image of food 12 which is the object to be heated through the transparent member. With this configuration, operation and effect similar to the operation and effect described above can also be obtained.
The present exemplary embodiment shows the configuration in which, in cooking device 11, two lighting units are provided on left wall surface 18, one at the front side and the other at the rear side, and two lighting units are provided on right wall surface 20, one at the front side and the other at the rear side. However, the lighting unit may be provided on top surface 17. In other words, an optimum number of lighting units may be provided at appropriate positions.

(Second exemplary embodiment)

Cooking device 11 according to a second exemplary embodiment of the present disclosure will described below. Cooking device 11 in the second exemplary embodiment of the present disclosure is largely different from cooking device 11 in the first exemplary embodiment in a configuration of lighting level controller 33 for changing the lighting level.
In the description below of cooking device 11 according to the second exemplary embodiment of the present disclosure, components that have the same function or configuration as components in the cooking device according to the first exemplary embodiment are denoted by the same reference marks, the detailed description of the components is omitted, and description in the first exemplary embodiment is applied.
FIG. 3 is a view showing a schematic configuration of a main part of the cooking device according to the second exemplary embodiment of the present disclosure. As shown in FIG. 3, in cooking device 11 according to the second exemplary embodiment of the present disclosure, lighting level controller 41 electrically connected to lightings 25a to 25d includes inside pulse width modulation controller 42 (it may be referred to as a PWM controller below). Pulse width modulation controller 42 drives LEDs constituting lightings 25a to 25d in pulses to change a pulse width for current flow, thereby changing the brightness, that is, the luminance of lightings 25a to 25d to a plurality of set values.
In the above configuration, when the cooking condition of food 12 is recognized based on an image captured by image capturing unit 23, four lightings 25a to 25d are all turned on as shown in FIG. 3.
If food 12 and tableware 35 placed into heating chamber 13 both have a whitish similar color with high brightness, illumination light in heating chamber 13 is reflected on food 12 and tableware 35, so that the illuminance is increased. Besides, in heating chamber 13, food 12 and each of lightings 25a to 25d are close to each other. Therefore, a portion detected as white by image capturing unit 23 due to concentration of emitted light is generated.
However, cooking device 11 in the present exemplary embodiment has lighting level controller 41 for changing a lighting level. Therefore, cooking device 11 changes the pulse width such that the luminance of each of lightings 25a to 25d is set to a predetermined set value according to a lighting pattern stored in lighting pattern storage unit 34. For example, cooking device 11 according to the present exemplary embodiment changes the pulse width so as to lower the luminance of each of lightings 25a to 25d by lighting level controller 41. The illuminance in heating chamber 13 is then lowered, and the brightness as a whole is decreased. Thus, it can be prevented that the amount of detected light for colors with high brightness exceeds a range.
On the other hand, the background image portion with low brightness other than food 12 and tableware 35 becomes solid in a dark color. Thus, similar whitish colors with higher brightness can be detected and captured in many tones by image capturing unit 23, whereby tones can be appropriately distinguished by image processor 32. Therefore, in cooking device 11 in the present exemplary embodiment, even if food 12 and tableware 35 both have a similar color, an image in which the color of food 12 and the color of tableware 35 are distinguished as different colors can be captured. Thus, image processor 32 can easily separate food 12 from tableware 35 that is a background near food 12 and specify the image of food 12. That is, image processor 32 can easily detect food 12 with high accuracy and identify the contour of food 12.
Further, the illuminance in heating chamber 13 can be changed by changing the luminance of each of lightings 25a to 25d to a plurality of different luminance values. With this configuration, a plurality of images having different illuminances can be captured. Accordingly, even if food 12 and the background near food 12 have a similar color, food 12 can be captured with a lighting level being set such that a color difference between food 12 and the background can be distinguished in many tones. Thus, image processor 32 can easily separate food 12 from the background and detect food 12 with high accuracy.
In addition, in image processor 32, a plurality of images obtained by changing the luminance values of lightings 25a to 25d according to a plurality of lighting patterns stored in lighting pattern storage unit 34 is compared. A contour whose position is changed and a contour whose position is unchanged according to the lighting pattern are distinguished from each other. With this configuration, the contour whose position is changed can be determined to be a local high illuminance portion and separated, whereby food 12 can be accurately detected.
The present exemplary embodiment shows the configuration in which, in cooking device 11, pulse width modulation controller 42 is used to change the luminance values of lightings 25a to 25d. However, cooking device 11 may be configured to change an amount of current to flow through the LEDs without changing the pulse width.
It is to be noted that, in the present disclosure, switching patterns of a plurality of luminance values executed by lightings 25a to 25d may be stored in lighting pattern storage unit 34 as lighting pattern data, for example. The lighting level may be changed such that lighting level controller 33, 41 switches the plurality of luminance values of the lighting units based on the data of a plurality of lighting patterns stored in lighting pattern storage unit 34.

INDUSTRIAL APPLICABILITY

The present disclosure provides a cooking device that can easily detect an object to be heated with high accuracy and identify the contour of the object to be heated, thereby being capable of accurately detect a condition of the object to be heated. Accordingly, the present disclosure is widely applicable to, for example, a cooking device that cooks food or the like.

REFERENCE MARKS IN THE DRAWINGS

11: cooking device
12: food (object to be heated)
13: heating chamber
17: top surface
18: left wall surface (wall surface)
19: rear surface (wall surface)
20: right wall surface (wall surface)
23: image capturing unit
24: through-hole
25a, 25b, 25c, 25d: lighting (lighting unit)
32: image processor
33, 41: lighting level controller
34: lighting pattern storage unit (storage unit)
35: tableware (nearby background)
42: pulse width modulation controller (PWM controller)

Claims

A cooking device comprising:
a heating chamber that houses an object to be heated;

an image capturing unit that captures an image of an inside of the heating chamber;

a lighting unit that emits light to the inside of the heating chamber;

a lighting level controller that changes a lighting level provided by the lighting unit; and

an image processor that specifies an image of the object to be heated in the image captured by the image capturing unit.
The cooking device according to claim 1, further comprising a lighting pattern storage unit that stores a plurality of lighting patterns, wherein
the lighting unit is configured to emit the light based on the plurality of lighting patterns, and
the lighting level controller is configured to cause the lighting unit to execute at least two of the plurality of lighting patterns.
The cooking device according to claim 1 or 2, wherein the lighting level controller is configured to change the lighting level provided by the lighting unit, according to brightness of the image captured by the image capturing unit.
The cooking device according to any one of claims 1 to 3, further comprising a plurality of the lighting units,
wherein the lighting level controller is configured to change the lighting level by controlling on and off of the plurality of the lighting units.
The cooking device according to claim 4, wherein
the plurality of the lighting units is disposed on at least one of a wall surface and a top surface of the heating chamber, and
the plurality of the lighting units has at least one combination of lighting units which are distant from each other across the image capturing unit at 30 degrees or more based on a center of the heating chamber in a plan view of the heating chamber as viewed from top.
The cooking device according to any one of claims 1 to 5, wherein
the lighting unit has a plurality of luminance values, and
the lighting level controller is configured to change the lighting level by switching the luminance values of the lighting unit.
The cooking device according to any one of claims 1 to 6, wherein the image capturing unit is configured to capture an image of the inside of the heating chamber through a through-hole or a transparent member formed in at least one of the wall surface and the top surface of the heating chamber.