JPH0129633Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a sense glass section for a transparent digitizer that is used by overlapping it on a pentouch-type touch panel display.

[Prior art]

FIG. 1 is a diagram showing an example of a circuit of an electromagnetic induction digitizer. In this figure, reference numerals 1 and 2 are groups of parallel conductors that are orthogonal to each other, and common lines 3 and 4 are connected to one end of the conductors, and switches of switch groups 5 and 6 are connected to the other end. Each switch in the switch groups 5 and 6 is scanned by the processing section 9 via the decoders 7 and 8, and is sequentially closed two at a time. 10 is an electromagnetic pen, which is excited by an oscillator 11, and a magnetic flux is generated from the tip 12 of the electromagnetic pen 10. When two switches of switch group 5 or 6 are closed, a sense coil is formed from two parallel conductors of parallel conductor group 1 or 2, respectively. When the magnetic fluxes from the two are interlinked, an electromotive force is induced, and the induced voltage is amplified by the amplifier 13. The processing unit 9 calculates the coordinate values of the tip 12 of the electromagnetic pen 10 by calculating based on the induced voltage of the sense coil.

The parallel conductor groups 1 and 2 are formed on the surface of a transparent glass plate or the like to make the digitizer transparent. Hereinafter, the part of the glass plate provided with the parallel conductor groups 1 and 2 will be referred to as a sense glass part. For the sense glass part, for example, parallel grooves are carved on both sides of a glass plate in directions perpendicular to each other on the front and back sides, and wires are buried in the grooves to form parallel conductor groups 1 and 2. ITO (indium tin oxide) deposited on
It can be made by etching a film to form parallel conductor groups 1 and 2.

However, the method of carving grooves in the glass has the disadvantage that it impairs the transparency of the glass, and the method of etching the ITO film on both sides of the glass plate has the disadvantage of being difficult to obtain high precision and difficult to manufacture.

Parallel conductor groups 1 and 2 are formed by etching ITO films deposited on separate glass plates, respectively.
There is also a method of stacking two glass plates so that the parallel conductor groups 1 and 2 are orthogonal. In this case, etching is easier, but since the two glass plates are independent and there is an air layer between them, there are four light reflecting surfaces, so when stacked on a display, the display As it gets darker, there is more reflection from ambient light from fluorescent lights, making it difficult to see the display. When two glass plates are stacked and the parallel conductor groups 1 and 2 are placed on opposing surfaces, it is necessary to sandwich an insulating sheet 16 between them as shown in FIG.

In FIG. 2, reference numerals 14 and 15 are glass plates, and parallel conductor groups 1 and 2 are formed on opposing surfaces thereof so as to be perpendicular to each other. A transparent insulating sheet 16 prevents the parallel conductor groups 1 and 2 from coming into contact with each other. In this case, the two glass plates and the spacer inserted between them are independent, and since there is an air layer between them, there are six light reflecting surfaces, and the display placed below. The increased reflection makes it difficult for display light to pass through, making the display even more difficult to see than when two glass plates are stacked together.

Furthermore, if a soft sheet such as a soft vinyl chloride sheet is used as the insulating sheet 16 and brought into direct contact with the glass plate, there will be parts where the insulating sheet 16 comes into close contact with the glass plate and other parts where it does not.
Areas that are in close contact reduce light reflection, making the display appear brighter than areas that are not in close contact.
Since the reflection of ambient light such as fluorescent lights is reduced and the whiteness is reduced, it also has the disadvantage of causing uneven brightness and visibility. In addition, Newton's rings also occur in the close contact area, making it extremely difficult to see.

When the entire surfaces of the glass plates 14 and 15 are bonded with adhesive, the insulating sheet 16 is not necessary because the adhesive has an insulating function, and since the adhesive adheres closely to the glass plates, it becomes the main light reflecting surface. The screen has two sides, making it easier to see the display, but air bubbles can easily enter the screen.
Furthermore, it is difficult to make the thickness of the adhesive uniform, which poses a problem in manufacturability.

[Summary of the idea]

This idea was made in view of the above points, and it consists of two glass plates put together to make glass, and a transparent plastic sheet interposed between them to insulate the conductors, and to create a light-reflecting surface. This reduces the number of layers to improve translucency and improves safety in the event of breakage. This invention will be explained in detail below with reference to the drawings.

[Example of idea]

FIG. 3 is a block diagram of a sense glass section according to an embodiment of this invention. In this figure, glass plate 1
4 and 15 are stacked on top of each other with a transparent plastic sheet 17 in between. This glass plate 14, 15
During processing, the plastic sheets 17 and 17 are heated and pressed in the thickness direction, so that the contact surfaces of the glass plates 14, 15 and the plastic sheet 17 are in close contact, and there is no space between them. Air space no longer exists. That is, the glass plate 14,1
5 and the plastic sheet 17 are laminated together to form a sense glass section. Parallel conductor groups 1 and 2 are present on the contact surfaces of the glass plates 14 and 15 with the plastic sheet 17, but the parallel conductor groups 1 and 2 are formed by etching an ITO film, and the thickness is Since it is 0.1 to 0.2 μm, it does not interfere with the construction of laminated glass.

Glass plates 14, 15 and plastic sheet 17
Since the contact surface is in close contact with the material, it has good translucency.
The reason for this is that the closer the ratio of the refractive index of light on both sides of the surface is to 1, the less the reflection of light on a surface becomes.
This is because the ratio of the refractive index is closer to 1 when the glass plates 14, 15 and the plastic sheet 17 are in close contact with each other than when air enters between them. The only substantial light reflecting surfaces are the surfaces of the glass plates 14 and 15 that are not in contact with the plastic sheet 17.

In this invention, since the glass is laminated, the glass plate 1
The fact that there is no unevenness in the thickness of the layer between 4 and 15 is also one of the reasons why the light transmittance is good. Also, compared to bonding with adhesive, air bubbles are less likely to enter.
Manufacturability is also good.

Digitizers are required to be safe because they are directly touched by the operator, and transparent digitizers whose input surface is made of glass need to be safe even if they break. Since laminated glass is safe because glass fragments are unlikely to scatter even if it breaks, the sense glass section of this invention is highly safe.

The plastic sheet 17 is usually made of PVB (polyvinyl butyral). glass plate 14,
15 may be soda glass, but may also be tempered glass. If you use tempered glass, you only need one piece on the side you touch. The use of tempered glass further improves safety, and also has the advantage that it is less likely to be scratched and its translucency is less likely to be impaired.

Note that this invention can also be applied to a transparent digitizer in which current is passed through the parallel conductor groups 1 and 2 on the surfaces of the glass plates 14 and 15, and the signals are detected by the electromagnetic pen 10. Furthermore, the glass plate 14,1
The present invention can also be applied to a digitizer (for example, an electrostatic induction digitizer) in which the parallel conductor groups 1 and 2 on the surface of 5 are not parallel conductor groups but a planar conductor film.

[Effect of idea]

As explained above, this idea consists of two transparent glass plates each having a conductor formed on their surface, the conductors facing each other, and a transparent plastic sheet interposed between them. Since the sense glass part is constructed as a laminated glass with the surfaces in close contact with each other so that there is no air space between them, there are essentially two reflective surfaces, which improves light transmission and allows the display to be seen clearly. , the sense glass section becomes very easy to see because the reflection of ambient light is reduced. Furthermore, it has the advantages of high safety and good manufacturability, and is extremely useful as an input surface of a digitizer for forming a touch panel by stacking it on a display.
In addition, if the surfaces of the glass plates on which both conductors are formed face each other and a plastic sheet is interposed between them to form a laminated glass, it becomes a completely sealed type, which has the advantage of preventing damage to the conductors during input. There is.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a circuit diagram of an electromagnetic induction digitizer, FIG. 2 is a diagram showing an example of the structure of a sense glass section, and FIG. 3 is a diagram showing an embodiment of this invention. In the figure, 1 and 2 are parallel conductor groups, 3 and 4 are common lines,
5 and 6 are switch groups, 7 and 8 are decoders, 9 is a processing unit, 10 is an electromagnetic pen, 11 is an oscillator, 12 is a tip, 13 is an amplifier, 14 and 15 are glass plates, 17
is a plastic sheet.

Claims (1)

[Claims for Utility Model Registration] (1) A plastic sheet is interposed between two glass plates each having a conductor formed on the surface thereof, so that there is no air space between the opposing surfaces of each glass plate and the plastic sheet. A sense glass part for a transparent digitizer characterized by being made of laminated glass in close contact with each other. (2) The sense glass part for a transparent digitizer according to claim (1) of claim 1, wherein at least one of the glass plates is made of tempered glass.