JP2008267633A - Glass top plate for cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass top plate for a cocker capable of improving both of a high-quality feeling and the visibility of display. <P>SOLUTION: This glass top plate 1 for the cooker has a light shielding portion 11 and a translucent display portion 12 on substrate glass 2, and used in a state of disposing a display body at a lower part of the display portion 12. The substrate glass 2 has a cooking face 21 composed of a smooth face and a rear face 22 composed of a coarsened face at a side opposite to the cooking face. The light shielding portion 11 is constituted by stacking a light shielding layer 3 on the rear face 22 of the substrate glass 2. The display portion 12 is constituted by adhering a translucent plate 5 to the rear face 22 of the substrate glass 2 through a transparent intermediate layer 4. At least an exposed face not faced to the transparent intermediate layer 4 of the translucent plate 5 is smooth. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glass top plate for a cooker that is placed on top of the cooker.

  Conventionally, a glass top plate for a cooker made of a glass plate is installed on the top of a cooker such as an electromagnetic cooker or a gas cooker. A heated object such as a pan is placed on the glass top plate for a cooker, and the heated object is heated by an induction heating coil that performs induction heating inside the cooker, or a heating device such as an electric heater or a halogen heater. Can cook. In particular, electromagnetic cookers tend to be increasingly demanded in recent years because of their high safety, and accordingly, the demand for glass top plates for cookers is also increasing.

The glass top plate for a cooker usually decorates the substrate glass with a color for the purpose of concealing the internal structure of the cooker or improving its design.
When using a glass plate having a smooth cooking surface and a rough surface as the substrate glass, and decorating the back surface, the reflection changes due to the unevenness of the rough surface on the back surface. The unevenness can be expressed as a texture. Therefore, such a substrate glass has been actively used from the viewpoint of design.
When a glass plate having a smooth cooking surface and back side surface is used as the substrate glass, the change in the reflection characteristics of the glass surface becomes poor.

In addition, the cooker is provided with an indicator made up of a liquid crystal, a light emitting diode (LED) or the like so that the user can grasp the operation state (temperature, heating power, etc.) of the device and a warning lamp at a glance from the cooking surface. There is a tendency.
And by arranging the above-mentioned indicator below the glass top plate for a cooker having a colorless low expansion crystallized glass excellent in translucency as a substrate glass, characters and luminescence itself are displayed on the cooking surface, and the temperature And making it possible to grasp the thermal power at a glance.

  In this case, in the region excluding the indicator display portion in the substrate glass, a light-shielding film is formed on at least one surface, for example, the back surface, of the front and back surfaces of the glass plate so as to conceal the built-in portion of the cooking device such as a heating device and wiring. It is necessary to apply such decorations.

  However, when the indicator is disposed below the top plate for the cooker, if a substrate glass having a smooth cooking surface and a rough surface on the back side is employed, an excellent texture is obtained. Although the decoration which it has can be given, there existed a problem that the display of the said LCD display seemed to be blurred by the unevenness | corrugation of a back side surface.

In addition, there is a cooking top plate that does not allow the inside of the cooking device such as the LED wiring to be seen from the non-shielding region of the light shielding film corresponding to the arrangement of the indicator made of LED, and does not misidentify the number displayed on the LED. It has been reported (Patent Document 1). However, there is no description regarding the visibility of the indicator which consists of liquid crystals in this technique.
Moreover, the top plate for cookers in which the glare-proof process was performed has been reported (patent document 2). This technology describes that when an antireflection film is formed on at least one side, preferably both sides, of a low expansion glass substrate corresponding to a liquid crystal display unit, light from illumination or the like is hardly reflected and the liquid crystal display is easy to see. Has been. However, when the low expansion glass substrate has irregularities, there is no effect on bleeding of the liquid crystal display due to the irregularities.

JP 2006-125645 A JP 2004-219920 A

  This invention is made | formed in view of this conventional problem, Comprising: It aims at providing the glass top plate for cookers which was compatible with the texture and the visibility of a display.

The present invention is a glass top plate for a cooking appliance that is provided with a light-shielding portion and a translucent display portion on a substrate glass, and is used so that a display body is disposed below the display portion,
The substrate glass has a cooking surface made of a smooth surface and a back side surface made of a roughened surface opposite to the cooking surface,
The light shielding part is provided by laminating a light shielding layer on the back side surface of the substrate glass,
The display unit is provided by adhering a translucent plate to the back side surface of the substrate glass via a transparent intermediate layer,
The translucent plate is in a glass top plate for a cooking appliance, wherein at least an exposed surface not facing the transparent intermediate layer is smooth.
In addition, the said cooking surface in a board | substrate glass is a surface which puts a pan etc. when using a heating cooker, The said back side surface is a surface which faces the heating apparatus which is a surface opposite to the said cooking surface. is there.

  The glass top plate for a cooker of the present invention employs a substrate glass having a cooking surface made of a smooth surface and a back side surface made of a rough surface opposite to the cooking surface, and a part thereof is translucent. And a light shielding portion having a light shielding property. The display unit has the special configuration described above. Thereby, the glass top plate for cooking appliances which has both the texture and the visibility of display can be obtained.

The light-shielding part is formed by laminating a light-shielding layer on the back side surface of a substrate glass having a cooking surface made of a smooth surface and a back side surface made of a roughened surface opposite to the cooking surface.
Thereby, while concealing the built-in part of a cooking appliance, the light-shielding part excellent in the design property can be obtained. That is, the unevenness on the back side surface of the substrate glass changes the reflection of light, and the texture from the unevenness can be imparted to the appearance from the cooking surface side, thereby improving the design.

The said display part adhere | attaches the translucent board which the surface which does not face at least a transparent intermediate | middle layer is smooth to the back side surface in the said substrate glass through a transparent intermediate | middle layer.
By filling the space between the back side of the substrate glass and the translucent plate with the transparent intermediate layer, it is possible to form a display unit that suppresses the unevenness of the back side of the substrate glass.
Thereby, the display of the display body which consists of a liquid crystal, LED, etc. which are arrange | positioned under the said display part can be recognized without a blur or distortion.
Thus, according to the present invention, it is possible to obtain a glass top plate for a cooker that achieves both a texture and visibility of display.

The glass top plate for a cooker according to the present invention employs a substrate glass having a cooking surface made of a smooth surface and a back side surface made of a roughened surface opposite to the cooking surface.
The cooking surface made of the smooth surface preferably has a surface roughness Rmax of less than 0.5 μm.
Here, the surface roughness Rmax is based on JIS B0601-1994.
When the surface roughness Rmax of the cooking surface is 0.5 μm or more, the display may appear distorted due to the unevenness of the cooking surface.

Moreover, it is preferable that the back side surface which consists of the said roughening surface is in the range whose surface roughness Rmax is 0.5-30 micrometers (Claim 3).
When the surface roughness Rmax of the back side surface is less than 0.5 μm, the glass surface is hardly changed, and the designability may not be sufficiently expressed. On the other hand, when the surface roughness Rmax of the back side surface exceeds 30 μm, it may be difficult to form a light shielding layer.

  The substrate glass can be produced, for example, by roll forming. When the molten glass raw material is formed into a glass plate through two cooling rollers, a substrate glass having the above-mentioned surface form can be produced by providing a function of forming irregularities on the glass on the surface of one of the rollers. .

Examples of the substrate glass include low expansion crystallized glass, tempered glass, and borosilicate glass.
The substrate glass may be colorless or colored, but preferably transmits visible light well (for example, the average transmittance of visible light having a wavelength of 400 to 800 nm is 15% or more). .

  The substrate glass is preferably transparent or translucent. Here, “transparent” refers to a case where the whiteness w measured by the colorimetric color difference meter is less than 30. Moreover, translucency means the case where the whiteness w measured by the colorimetric color difference meter is 30 or more and less than 70.

The whiteness w is a numerical value represented by the ratio of the amount of light reflection, where the light reflection amount of the magnesium oxide standard white plate is 100 and true black is 0. Specifically, L, a, and b values are measured with a C2 light source using a colorimetric color difference meter (for example, ZE2000 manufactured by Nippon Denshoku Industries Co., Ltd.), and the following formula W (whiteness) = 100 − [(100− L) ² + a ² + b ² ] ^1/2 .
The substrate glass may be a commercially available crystallized glass.

Moreover, the said light shielding part is provided by laminating | stacking a light shielding layer on the said back side surface in the said substrate glass.
Various known layers can be applied as the light shielding layer. Specifically, for example, as will be described later, a layer composed of a raster color, a layer composed of a glass composition and an inorganic pigment, a layer composed of a pearl tone material and a silicone resin or a siliceous sol, and the like can be mentioned.
The light shielding layer may be formed by laminating the above-described layers alone on the back side surface or by laminating a plurality of layers.

Moreover, the said display part is provided by adhere | attaching a translucent board through the transparent intermediate | middle layer on the back side surface in the said board | substrate glass.
Moreover, the said transparent intermediate | middle layer and a translucent board may cover a part of said light-shielding part.

The transparent intermediate layer is preferably made of a transparent resin having a refractive index closer to that of glass than air and transmitting visible light.
The resin preferably has flexibility in order to relieve thermal stress.

As the resin, UV or visible light curable type, thermoplastic or adhesive type can be used. Specifically, for example, silicone resin (addition reaction type, peroxide curable type), polyimide resin (aromatic polyimide) , Epoxy resins, acrylic resins, or resins mainly composed of these modified types.
The transparent intermediate layer is preferably made of a transparent silicone resin that does not change even when a temperature of about 200 ° C. is applied and does not lose its adhesive strength or holding power.

Moreover, it is preferable that the thickness of the said transparent intermediate | middle layer is 5 micrometers-2 mm (Claim 5).
When the thickness of the transparent intermediate layer is less than 5 μm, the adhesion between the substrate glass and the translucent plate may be insufficient. On the other hand, when the thickness of the transparent intermediate layer exceeds 2 mm, cooking is performed. Since it is bulky when the glass top plate for dexterity is piled up, there is a risk of waste during storage or transportation.

The translucent plate has at least an exposed surface that does not face the transparent intermediate layer.
If the exposed surface which does not face at least the transparent intermediate layer is not smooth, there is a problem that the display is distorted.
Therefore, it is preferable that the exposed surface not facing the transparent intermediate layer has a surface roughness Rmax of less than 0.5 μm.

The translucent plate is preferably transparent (Claim 7).
In this case, particularly excellent visibility can be obtained.
Moreover, a glass plate or a resin plate can be used as the translucent plate.
The translucent plate is particularly preferably a heat-resistant glass plate.
In order to avoid thermal stress cracking, it is more preferable to use the same material as the substrate glass or low-expansion glass (such as borosilicate glass).

Moreover, it is preferable that the thickness of the said translucent board is 1-4 mm (Claim 9).
When the thickness of the translucent plate is less than 1 mm, impact cracking may occur. On the other hand, when the thickness of the translucent plate exceeds 4 mm, the glass top plate for a cooker is overlaid. Therefore, there is a risk of waste during storage or transportation.

As a method of adhering the translucent plate to the substrate glass, a laminated glass method and a bonding method are mainly exemplified.
The laminated glass method is a method used for car window glass, security glass, etc., and sandwiching a resin for a transparent intermediate layer between a substrate glass and a translucent plate, and heating and melting in a vacuum state It is a method of pasting together.
In the bonding method, first, a resin for a transparent intermediate layer is applied to a substrate glass. Then, the translucent plate is tilted to approach the resin and brought into contact. The inclination is made shallow so that air bubbles are not involved, and the whole bonded portion is infiltrated.

Moreover, it is preferable that the said display body is an indicator which consists of a liquid crystal or a light-emitting body (Claim 10).
Since the display part of the said glass top plate for cookers is excellent in visibility, the display of the indicator which consists of a liquid crystal or a light-emitting body can also be recognized clearly.
Examples of the light emitter include a light emitting diode (LED).

  In addition, when a translucent black or a translucent plate with a mirror-like expression is adopted as the translucent plate, for example, a light emitting diode (LED) disclosed in Patent Document 1 as a display body. When the LED is not lit, the inside of the device can be concealed to give a black or mirror-like single-surface appearance. Further, when the LED is lit, only the emitted numbers can be clearly displayed without blurring the outline, and the displayed numbers can be prevented from being misidentified.

The light-shielding layer preferably has a layer made of a pearl tone paint made of a pearl tone material and a silicone resin or a siliceous sol.
In this case, the designability can be improved without reducing the original strength of the substrate glass.

As the pearl tone material, it is preferable to use a material coated with an inorganic pigment with titanium oxide, zirconium oxide, iron oxide or the like. In addition, a specific iris color can be developed by changing the film thickness of titanium oxide, iron oxide, or the like.
The silicone resin is a polymer of an organosilicon compound having a siloxane bond as a main skeleton.

Moreover, as said siliceous sol, the silica sol obtained by hydrolyzing ethyl silicate etc., colloidal silica sol, etc. can be used, for example.
Further, the layer made of the above-mentioned pearl color paint may contain an inorganic pigment in a range of not more than 20% by weight when the total content of the pearl color material and the silicone resin or siliceous sol is 100% by weight. good. The inorganic pigment described above can be used as the inorganic pigment.

The layer composed of the pearl-colored paint composed of the pearl-colored material and the silicone resin or siliceous sol can be formed by applying the pearl-colored paint to the back side of the substrate glass and baking at 700 to 900 ° C. preferable.
The application of the pearl color paint is preferably performed by screen printing.

Moreover, it is preferable that the said light shielding layer has a layer which consists of an inorganic pigment and a glass composition (Claim 12).
In this case, the design can be improved without reducing the original strength of the substrate glass.

Examples of the inorganic pigment include a white inorganic pigment, a black inorganic pigment, a gray inorganic pigment, a yellow inorganic pigment, a brown inorganic pigment, a green inorganic pigment, a blue inorganic pigment, a pink inorganic pigment, and a mica pigment.
Specifically, as the white inorganic pigment, for _{example, TiO 2, ZrO 2, ZrSiO} 4, Al 2 O 3, 3Al 2 O 3 -2SiO 2, Li 2 O · Al 2 O 3 · 8SiO 2 or the like can be mentioned It is done.

Examples of the black inorganic pigment include Cr-Fe-based oxides, Co-Mn-Cr-Fe-based oxides, Co-Ni-Cr-Fe-based oxides, and Co-Ni-Cr-Fe-Mn-based materials. An oxide etc. are mentioned.
Examples of the gray inorganic pigment include Sn-Sb-based oxides and Sn-Sb-V-based oxides.

Examples of the yellow inorganic pigment include Sn-V oxides, Zr-V oxides, Zr-Si-Pr oxides, Ti-Cr-Sb oxides, and the like.
Examples of the brown inorganic pigment include Zn-Al-Cr-Fe-based oxides and Zn-Mn-Al-Cr-Fe-based oxides.

Examples of the green inorganic pigment include Ca—Cr—Si oxides, Cr—Al oxides, Co—Zn—Al—Cr oxides, and Zr—Si—Pr—V oxides. It is done.
Examples of the blue powder include Co—Al—Zn-based oxides, Co—Al-based oxides, and Zr—Si-based oxides.

Examples of the pink inorganic pigment include Mn—Al oxides, Ca—Sn—Si—Cr oxides, Sn—Cr oxides, and Zr—Si—Fe oxides.
Examples of the mica pigment include Iriodin manufactured by Merck Co., Ltd.
These pigments can be mixed in an arbitrary ratio so as to obtain a desired color.

The glass composition is preferably a lead-free glass composition in consideration of recyclability and the like.
Moreover, it is preferable that the said glass composition is 650 degrees C or less in a softening point. Further, the glass _{composition, SiO 2, Al 2 O 3} , B 2 O 3, Li 2 O, Na 2 O, K 2 O, and containing ZrO ₂ as an essential component, CaO optionally, SrO It is more preferable to use a lead-free glass composition that contains at least one of BaO, ZnO, and TiO ₂ as an additive component and that is welded by heat treatment at 750 to 900 ° C.

  To the above glass composition, a low expansion crystal forming agent, a crystallization agent, a melting agent, an adhesion improver, etc. are added for the purpose of further improving crystallinity, low expansion, mechanical strength, and adhesive strength. May be.

The low-expansion crystal-forming agent crystallizes the glass composition by firing to precipitate low-expansion crystals. As the low expansion crystal forming agent, for example, a Li ₂ O ₃ —Al ₂ O ₃ —SiO ₂ based low expansion crystal forming agent can be used.

Moreover, the layer which consists of the said inorganic pigment and a glass composition apply | coats the paste which consists of an inorganic pigment, a glass composition, and organic resin on the back side surface of the said board | substrate glass, and is baked at 700-900 degreeC. It is preferable to form.
The paste is preferably applied by screen printing.

Moreover, it is preferable that the said light shielding layer has a layer which consists of a raster color.
The raster color is a diluted solution of an organometallic compound.
Examples of the raster colors include organic materials such as Au, Pt, Pd, Rh, Ru, Bi, Sn, Ni, Fe, Cr, Ti, Ca, Si, Ba, Sr, Mg, Ag, Zr, In, and Mn. A diluted solution of a metal compound can be mentioned. A plurality of these organometallic compound diluted solutions can be mixed at an arbitrary ratio.

The layer composed of the raster color is preferably formed by applying the raster color to the back side surface of the substrate glass and baking at 600 to 900 ° C.
Further, the application of the raster color is preferably performed by screen printing.

The substrate glass preferably has a linear thermal expansion coefficient of −10 × 10 ⁻⁷ to 80 × 10 ⁻⁷ / K (at 30 to 500 ° C.).
When the linear thermal expansion coefficient of the substrate glass deviates from the range of −10 to 80 × 10 ⁻⁷ / K (at 30 to 500 ° C.), it may not be suitable as a substrate glass used for a glass top plate for a cooker. .

The substrate glass is preferably a transparent low expansion crystallized glass plate having a main crystal of β-quartz solid solution or β-spodumene (Claim 15).
The transparent low expansion crystallized glass plate having the β-quartz solid solution or β-spodumene as the main crystal is particularly suitable as a substrate glass for a glass top plate for an electromagnetic cooker.

Moreover, it is preferable that the painting glass decoration layer which consists of a glass composition is formed in the cooking surface side of the glass top plate for cookers (Claim 16).
In this case, it is possible to prevent the cooking surface from being damaged by wear of the heated object such as a pan and the cooking surface of the glass top plate for a cooker, or to obtain an effect of making the heated object difficult to slip. it can.

Moreover, it is preferable that the said decoration glass decoration layer is 1-15 micrometers in film thickness. When the film thickness of the decorative glass decorative layer is less than 1 μm, the above-described effects may not be sufficiently obtained. On the other hand, when the film thickness of the said decorative glass decoration layer exceeds 15 micrometers, there exists a possibility that the said decorative glass decoration layer may peel.
The film thickness of the decorative glass decorative layer is more preferably 2 to 10 μm.

The glass composition is preferably a lead-free glass composition in consideration of recyclability and the like, and a glass composition similar to the glass composition used for the layer composed of the above-mentioned inorganic pigment and glass composition should be used. Is preferred.
The painted glass decorative layer may contain an inorganic pigment or the like in addition to the glass composition.
The inorganic pigment described above can be used as the inorganic pigment.

Moreover, it is preferable that the said decorating glass decoration layer is formed so that it may become an arbitrary pattern (Claim 17).
Examples of the arbitrary pattern include a stone shape, a line shape, and a solid having a certain area.

Example 1
This example explains the example concerning the glass top plate for cookers of the present invention.
In this example, as shown in FIG.
A glass top plate 1 (sample E1) for a cooking appliance is used in which a light shielding part 11 and a translucent display part 12 are provided on a substrate glass 2, and a display body is disposed below the display part 12. Produced.
The light shielding portion 11 is provided by laminating the light shielding layer 3 on the back side surface 22 of the substrate glass 2.
The display unit 12 is provided by adhering the translucent plate 5 to the back side surface 22 of the substrate glass 2 through the transparent intermediate layer 4.

When the glass top plate 1 for a cooker of this example is actually used for a cooker, a heating device such as an induction heating coil, an electric heater, or a halogen heater is provided below the light shielding portion 11. A device light emitting unit is provided below the display unit 12.
This will be described in detail below.

First, Neoceram N-0 was prepared as the substrate glass 2. The substrate glass 2 has a cooking surface 21 made of a smooth surface having a surface roughness Rmax of 0.4 μm and a back side surface made of a roughened surface having a surface roughness Rmax of 0.75 μm opposite to the cooking surface 21. 22.
Next, as the paste for the light-shielding layer 3, a pearl-like material (Iriodin 123 manufactured by Silver Pearl Merck Co., Ltd.), a silicone resin, and an organic vehicle for screen printing, and a black raster painting material are prepared. did.

Further, an addition reaction type silicone resin was prepared as the resin for the transparent intermediate layer 4.
Moreover, as the translucent plate 5, a plate made of borosilicate glass and having a thickness of 1 mm was prepared. In the translucent plate 5, the surface 51 that does not face the transparent intermediate layer 4 is a smooth surface having a surface roughness Rmax of 0.3 μm.

Next, a manufacturing method will be described.
First, the pearl color paint is applied to a part of the back side surface 22 of the glass substrate 2 (a part other than the part to be the display part 12) using a stainless steel 250 mesh screen, and baked at 820 ° C. It was. Thereby, a pearl tone layer 31 having a film thickness of 15 μm was formed.

  Next, the black raster painting material was applied onto the pearl tone layer 31 using a stainless steel 350 mesh screen and baked at 820 ° C. Thereby, the raster layer 32 having a thickness of 600 nm was formed, and the light shielding layer 3 was formed.

Next, the resin for the transparent intermediate layer was applied to the portion to be the display unit 12. The translucent plate was tilted and brought close to the resin, brought into contact with it, and the tilt was made shallow so as not to entrain air bubbles, and the entire display unit 12 was permeated to produce a glass top plate 1 for a cooker.
The light-shielding portion 11 of the glass top plate 1 for a cooking appliance has a pearly silver gray expression that varies depending on the viewing angle.

In this example, the transparent intermediate layer and the translucent plate are formed so as to cover a part of the light shielding layer, but hardly affect the expression of the light shielding part.
In addition to the display portion, a light shielding layer composed of two layers of a pearl tone layer and a raster layer is formed. However, various known layers may be applied to the light shielding layer, or may not be formed. .

(Comparative Example 1)
This example demonstrates the comparative example concerning the glass top plate for cookers of this invention.
In this example, the display unit of Example 1 is changed to a state in which nothing is formed on the back side surface of the substrate glass and the back side surface of the substrate glass is exposed, and a glass top plate (sample C1) for a cooker is produced. This is an example. Others were the same as in Example 1.

(Experimental example)
A visibility test was performed on the display portions of the sample E1 and the sample C1 prepared in Example 1 and Comparative Example 1.
In the visibility test, a display body was disposed below the display unit (a position 5 mm below the back side surface of the substrate glass), and the visibility of the display was evaluated. FIG. 2 shows a photograph taken from the cooking surface side as a drawing substitute photograph. FIG. 2 (a) is a photograph of the sample E1, and FIG. 2 (b) is a photograph of the sample C1.

As can be seen from FIG. 2 (a), the sample E1 as an example has a feeling of unevenness on the back side surface of the substrate glass, the display on the display body is easily recognized, and is excellent in visibility.
Further, as is known from FIG. 2B, the sample C1 as a comparative example is displayed with a blurred display on the display body and is difficult to recognize.
From this, according to this invention, it turns out that the glass top plate for cooking appliances which can make a texture and the visibility of a display compatible can be obtained.

Explanatory drawing which shows the glass top plate for cookers in Example 1. FIG. The drawing substitute photograph which shows the visibility test in an experiment example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass top plate for cookers 11 Light-shielding part 12 Display part 2 Substrate glass 21 Cooking surface 22 Back side surface 3 Light-shielding layer 4 Transparent intermediate | middle layer 5 Translucent board

Claims (17)

A glass top plate for a cooker, which is provided with a light-shielding part and a translucent display part on a substrate glass, and is used so that a display body is arranged below the display part,
The substrate glass has a cooking surface made of a smooth surface and a back side surface made of a roughened surface opposite to the cooking surface,
The light shielding part is provided by laminating a light shielding layer on the back side surface of the substrate glass,
The display unit is provided by adhering a translucent plate to the back side surface of the substrate glass via a transparent intermediate layer,
The glass top plate for a cooker, wherein the translucent plate has a smooth exposed surface that does not face at least the transparent intermediate layer.   2. The glass top plate for a cooker according to claim 1, wherein the cooking surface of the substrate glass has a surface roughness Rmax of less than 0.5 [mu] m.   3. The glass top plate for a cooker according to claim 1, wherein the back side surface of the substrate glass has a surface roughness Rmax in the range of 0.5 to 30 [mu] m.   The glass top plate for a cooker according to any one of claims 1 to 3, wherein the transparent intermediate layer is made of a transparent silicone resin.   5. The glass top plate for a cooker according to claim 1, wherein the transparent intermediate layer has a thickness of 5 μm to 2 mm.   6. The glass top plate for a cooker according to any one of claims 1 to 5, wherein the exposed surface not facing the transparent intermediate layer of the translucent plate has a surface roughness Rmax of less than 0.5 [mu] m. .   The glass top plate for a cooker according to any one of claims 1 to 6, wherein the translucent plate is transparent.   The glass top plate for a cooker according to any one of claims 1 to 7, wherein the translucent plate is a heat-resistant glass plate.   The glass top plate for a cooker according to any one of claims 1 to 8, wherein the translucent plate has a thickness of 1 to 4 mm.   The glass top plate for a cooker according to any one of claims 1 to 9, wherein the display body is an indicator made of a liquid crystal or a light emitter.   11. The glass top plate for a cooker according to any one of claims 1 to 10, wherein the light shielding layer has a layer made of a pearl-colored paint made of a pearl-colored material and a silicone resin or a siliceous sol.   The glass top plate for a cooker according to any one of claims 1 to 11, wherein the light shielding layer includes a layer made of an inorganic pigment and a glass composition.   The glass top plate for a cooking device according to any one of claims 1 to 12, wherein the light shielding layer has a layer composed of a raster color. 14. The cooking according to claim 1, wherein the substrate glass has a linear thermal expansion coefficient of −10 × 10 ⁻⁷ to 80 × 10 ⁻⁷ / K (at 30 to 500 ° C.). Glass top plate for dexterity.   15. The glass top plate for a cooker according to any one of claims 1 to 14, wherein the substrate glass is a transparent low expansion crystallized glass plate having a β-quartz solid solution or β-spodumene as a main crystal.   The glass top plate for a cooker according to any one of claims 1 to 15, wherein a decorative glass decorative layer made of a glass composition is formed on the cooking surface side of the glass top plate for a cooker.   The glass top plate for a cooker according to claim 16, wherein the decorative glass decorative layer is formed to have an arbitrary pattern.