JP6965575B2 - Touch panel sensor board, interactive screen, and electronic blackboard with interactive screen - Google Patents

Description

The present invention relates to a touch panel sensor substrate, an interactive screen, and an electronic blackboard including the interactive screen.

In recent years, display devices equipped with a touch panel have rapidly become widespread. Here, the touch panel is an input device capable of acquiring position information related to the contact position (touch position) of the indicator body with respect to the panel surface.

The main position detection methods of the touch panel are roughly classified into an optical method, a resistance film method, and a capacitance method. As the capacitance method, there are a surface type capacitance method and a projection type capacitance method. In recent years, among the above-mentioned detection methods, in particular, the demand for a multi-touch, that is, a projection type capacitance type touch panel capable of simultaneously detecting a plurality of touches on an image display surface is increasing. In the projection type capacitance type touch panel, when a fingertip or the like approaches the image display surface, a large number of changes in the capacitance of the electrodes in the vicinity are arranged along the XY direction on the back side of the display surface. The touch position is detected as position coordinates on the touch panel by sensing with electrodes (Patent Document 1).

When the above-mentioned capacitive touch panel is mounted on various LED display devices of the type that shines light from the back side of the display screen to display character information, etc., the light source on the back side of the display screen is used. In order to ensure the translucency of light, it is necessary to use a transparent conductive material such as ITO for the position detection electrode of the touch panel arranged behind the display screen.

In addition, there are various sizes of the image display surface of the display device equipped with the touch panel, that is, the size of the information input screen by touch, from a lightweight and small device such as a smartphone to a large device such as an electronic blackboard. Each has already been put into practical use.

It is a display device equipped with a projection type capacitive touch panel capable of multi-touch, and it is one of the display devices with a large screen size. In recent years, it has rapidly become widespread in offices and schools. There is an interactive electronic touch panel. Interactive electronic blackboards can project characters and images output from information processing devices such as personal computers onto the image display surface, and can also draw by hand on the image display surface on which information is displayed. Moreover, it is an image display device having a bidirectional information processing function capable of outputting drawn characters and images to an information processing device and processing them (see Patent Document 2).

This interactive electronic blackboard is required to be capable of detecting multi-touch input with high accuracy on a display screen much larger than that of a smartphone or the like. The above-mentioned transparent electrode material, which has been widely used as an electrode material for position detection, has excellent translucency, but has a higher electric resistance value than a metal electrode made of copper foil or the like, and is similar to an electronic blackboard. It was difficult to maintain sufficient responsiveness on a large touch panel. In addition, this transparent electrode material is prone to the problem of resistance change (high resistance shift) with respect to bending, and the mechanical strength is also due to slight bending or distortion of the screen, especially when the screen is large. However, the risk of tearing is high, and it is not suitable for large touch panel display devices such as the above-mentioned electronic blackboard in order to ensure the quality stability and durability of the product.

Here, in the front projection type electronic blackboard that projects information from the front of the image display surface, it is not necessary to secure the translucency of the light from the light source on the back side of the display screen. Therefore, in this case, the electrode for position detection does not necessarily have to be a transparent electrode. However, on the other hand, in this case, when the position detection electrode is configured with the same circuit shape by using a metal electrode made of copper foil or the like, the area of the image display image is much larger than that of a smartphone or the like. As the amount of metal forming the electrodes in the touch panel sensor covering the above increases, the weight of the entire device also increases remarkably. Then, in the manufacturing process of various devices equipped with a touch panel, the excessive weight of the touch panel sensor causes distortion on the image display surface, which adversely affects the touch accuracy and sensitivity, or facilitates the transportation and installation work of the product. There was a problem that the sex was impaired.

JP-A-2017-68819 Japanese Unexamined Patent Publication No. 2012-73360

The present invention has been made in view of such a situation, and is a substrate for a touch panel sensor that can be suitably used for a front projection type interactive electronic whiteboard, and can be used for touch input even on a large interactive screen. Provided are a touch panel sensor substrate capable of maintaining good responsiveness and sufficiently suppressing an increase in the weight of a touch panel due to an increase in size, and an interactive screen and an electronic whiteboard using the substrate. With the goal.

As a result of intensive research, the present inventors have constructed a mesh-like metal foil in which a plurality of openings are dispersedly formed as electrodes for position detection of a projection type capacitance type touch panel sensor substrate. As a result, it was found that the above problems could be solved, and the present invention was completed. Specifically, the present invention provides the following.

(1) A projection type capacitance type touch panel sensor substrate, which is composed of a plurality of X coordinate detection electrodes formed in parallel along the Y direction in a plan view on one surface of a support substrate. Y coordinate consisting of a group of coordinate detection electrodes and a plurality of Y coordinate detection electrodes formed in parallel along the X direction in a plan view on another surface of the support substrate or on one surface of the other support substrate. The X-coordinate detection electrode and the Y-coordinate detection electrode include a detection electrode group, and the X-coordinate detection electrode and the Y-coordinate detection electrode are made of a mesh-shaped metal foil in which a plurality of openings are dispersedly formed, and the opening ratio of the metal foil is 25% or more and 50%. The following substrate for touch panel sensor.

In the invention of (1), the electrode for position detection of the projection type capacitance type touch panel sensor substrate is formed of a highly conductive metal electrode, and the metal electrode is within a predetermined aperture ratio range. It was composed of a mesh-shaped metal foil. According to this, even when the device on which the touch panel is mounted has a large display screen, it is possible to obtain a touch panel sensor substrate that can form a touch panel that is lightweight and has excellent responsiveness.

The "mesh-shaped metal foil" in the present specification is a plate-shaped metal member as a whole, and is dispersed substantially evenly on the entire surface thereof to form a large number of openings having substantially the same shape and size. It refers to the metal foil that is used. A conventionally known wire net shape formed only by wire members on lines intersecting vertically and horizontally, which is not plate-shaped as a whole, is not included in this "mesh-shaped metal foil". The difference between the wire net-shaped one and the "mesh-shaped metal foil" can be distinguished by substantially determining the difference in aperture ratio. If it has the above-mentioned wire mesh shape, the aperture ratio is considered to be at least 90% or more, but the "mesh-shaped metal foil" according to the present invention has an aperture ratio of 80% or less, that is, an opening is formed. It is specified that the portion of the plate base material that has not been used remains more than 20%. Further, the aperture ratio referred to here is, for example, in the case of a mesh-shaped metal foil, the ratio of the area of the opening portion to the total surface area including the opening portion on one surface of the metal foil as the base material. To tell.

(2) The touch panel according to (1), wherein the X-coordinate detection electrode and the Y-coordinate detection electrode are both formed by connecting a plurality of electrode pads having a rectangular shape, a circular shape, or an elliptical shape. Sensor board.

In the invention of (2), for example, each electrode for position detection has a planar shape in which a plurality of diamond-shaped electrode pads as shown in FIG. 3 are connected. According to this, the sensor area can be made larger, and a touch panel having better detection and sensitivity of the change intensity distribution can be configured.

In the embodiment in which a plurality of electrode pads are connected to each other to form the X-coordinate detection electrode and the Y-coordinate detection electrode as in the invention of (2), for example, a thin line-shaped electrode pad is connected to each other. Even if the aperture ratio of the portion or the like is not necessarily in the above range, if the aperture ratio according to the above definition for each electrode pad is in the range of 25% or more and 50% or less, it is naturally within the range of the present invention.

(3) The substrate for a touch panel sensor according to (1) or (2), wherein the mesh-shaped metal foil is a copper foil.

In the invention of (3), each electrode for position detection is made of copper, which has higher physical strength than a transparent conductive material such as ITO, has excellent conductivity among various metal members, and has a good balance between performance and cost. It was decided to. According to this, in the touch panel sensor substrate of (1) or (2), the electrical conductivity of each electrode is maintained at a higher level, and the responsiveness to touch input is better even in a large touch panel sensor substrate. Can be maintained at. In addition, the strength and durability against bending of the electrodes are also increased.

(4) The surface on which the X-coordinate detection electrode group or the Y-coordinate detection electrode group is formed on the support substrate or the other support substrate is insulated from each electrode even in a range where each electrode does not exist. The substrate for a touch panel sensor according to any one of (1) to (3), wherein a non-conducting metal foil layer made of the mesh-shaped metal foil is formed by being separated by a slit.

In the invention of (4), substantially the entire surface on the support substrate is covered with a metal layer composed of each electrode and an outrageous metal layer. Since the outrageous metal layer is present on substantially the entire surface of the support substrate, the strength of the touch panel sensor substrate according to any one of (1) to (3) against bending can be further improved.

(5) The touch panel sensor substrate according to any one of (1) to (4), wherein the support substrate is a flexible resin film.

In the invention of (5), the touch panel sensor substrate according to any one of (1) to (4) is a flexible substrate type film-like member. According to this, it is possible to obtain an interactive screen which is not only thin but also excellent in shape followability to various shapes of installation surfaces due to the flexibility of the support substrate. Further, when not in use, the entire screen can be wound into a roll to be moved and stored, and the handleability of the electronic blackboard can be remarkably improved. In addition, in this specification, "having flexibility" means "it is possible to bend a radius of curvature to 1 m, preferably 50 cm".

(6) An interactive screen in which a reflective screen for front projection is installed on the surface of the touch panel sensor substrate according to any one of (1) to (5).

In the invention of (6), an interactive screen on which the touch panel sensor substrate according to any one of (1) to (5) is mounted is used. As a result, the above-mentioned effects of the inventions (1) to (5) are enjoyed, the responsiveness to the touch input is well maintained, and the weight increase of the touch panel is sufficiently suppressed. You can get an interactive screen for an electronic blackboard.

(7) An interactive screen in which a reflective screen for front projection is installed on the surface of the touch panel sensor substrate according to (5), wherein the reflective screen is a large screen having a diagonal length of 30 inches or more. An interactive screen that can be rolled up on a roll when not in use.

In the invention of (7), the flexible substrate type touch sensor described in (5) is combined with a particularly large reflective screen to form a large interactive screen. According to this, in a large electronic blackboard with a screen size of 30 inches or more, it is possible to achieve both weight reduction and maintenance of responsiveness, which have been conventionally restricted, and as described above, an interactive screen with extremely excellent handleability. Can be obtained.

(8) An electronic blackboard comprising the interactive screen and the front projection device according to (6) or (7).

In the invention of (8), it is possible to obtain an electronic blackboard that is lightweight, easy to handle, and has excellent responsiveness to touch input by enjoying the above-mentioned effects of the interactive screen according to (6) or (7).

According to the present invention, it is a touch panel sensor substrate that can be suitably used for a front projection type interactive electronic whiteboard, and can maintain good responsiveness to touch input even on a large interactive screen. Moreover, it is possible to provide a touch panel sensor substrate, an interactive screen using the same, and an electronic whiteboard, which can sufficiently suppress an increase in the weight of the touch panel due to an increase in size.

It is sectional drawing which shows typically the layer structure of the substrate for a touch panel sensor of this invention. It is a top view which shows typically the plane structure of the substrate for a touch panel sensor of this invention. FIG. 5 is a partially enlarged plan view schematically showing the planar shapes of the X-coordinate detection electrode group and the outrageous metal layer in another embodiment of the touch panel sensor substrate of the present invention. FIG. 5 is a partially enlarged plan view schematically showing the planar shapes of the Y coordinate detection electrode group and the outrageous metal layer in another embodiment of the touch panel sensor substrate of the present invention. It is a top view which shows typically the planar shape of the electrode pad which constitutes each electrode in another embodiment of the touch panel sensor substrate of this invention. It is a perspective view of the electronic blackboard provided with the interactive screen made by using the substrate for a touch panel sensor of this invention.

Hereinafter, first, an interactive screen that can be configured by using the touch panel sensor substrate of the present invention and an overall configuration of an electronic blackboard including the interactive screen will be described. Subsequently, details of the touch panel sensor substrate of the present invention and each member constituting the substrate will be described. The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention.

<Electronic blackboard with interactive screen>
FIG. 1 is a perspective view showing the configuration of an electronic blackboard 100 including an interactive screen 10 configured by using the touch panel sensor substrate 1 of the present invention. The electronic blackboard 100 includes at least an interactive screen 10 and a front projection device 3. The interactive screen 10 is formed by installing the touch panel sensor substrate 1 of the present invention on the back side of the reflective screen 2 for front projection. Further, the electronic blackboard 100 may further include an information processing device such as a personal computer as a control unit (not shown), if necessary. The size of the image display surface of the electronic whiteboard 100 is not particularly limited as long as the diagonal length is in the range of about 15 inches to 100 inches, but the touch panel sensor substrate of the present invention has a diagonal length of 30. It can be preferably used for an electronic blackboard having a large image display surface of an inch or more. Further, the touch panel sensor substrate of the present invention has a particularly advantageous effect of weight reduction when used on a large image display surface having a diagonal length of 70 inches or more, which is particularly heavy.

As shown in FIG. 1, the reflective screen 2 arranged on the image display surface side of the interactive screen 10 transmits the image light projected from the front projection device 3 installed diagonally above the image display surface side on the surface thereof. It is a sheet-shaped or plate-shaped light-reflecting base material that reflects substantially in the front direction and is displayed on the surface as visible image information. At the same time, information can be input to the reflective screen 2 via a dedicated input device or the like, and the surface of the reflective screen 2 is handwritten using a general-purpose writing instrument such as a marker like a general whiteboard or the like. Information such as characters and figures can be drawn, and the drawn characters can be erased. The installation position of the front projection device 3 may be a position that does not interfere with the reflected light when it is assumed that the projected image light is reflected substantially in the front direction, and the front projection device 3 is installed diagonally upward as illustrated above. Not limited to.

The front projection device 3 is a light source unit that projects image light onto the interactive screen 10 from diagonally above the image display surface of the reflection screen 2. As shown in FIG. 1, the front projection device 3 may be installed in a mounting portion provided so as to extend from the frame portion of the electronic blackboard or the like toward the image display surface side of the interactive screen 10. Alternatively, it may be in a form separate from the interactive screen 10. Specific examples of the latter include a form in which the ceiling is appropriately attached to the ceiling of the room, a flat placement on the floor in a manner capable of appropriate projection, and the like. Further, as the front projection device 3, a general-purpose projection device can be appropriately used. For example, a light source device such as a DLP or LCD system may be used, or a digital camera or the like having a function as a projection device may be used, which can be appropriately selected according to the purpose of use and the environment of use.

Information can be input to the interactive screen 10 by touching the image display surface of the reflective screen 2 with a touch pen, a marker using conductive ink, a finger, or the like. The detection of the touch position on the image display surface is performed by the touch panel sensor substrate 1 installed on the back side of the reflective screen 2 in the interactive screen 10. The details of the touch panel sensor substrate 1 will be described later.

The control unit (not shown) of the electronic blackboard 100 composed of a personal computer or the like is based on the output of the image information displayed on the interactive screen 10 to the front projection device 3 and the detection signal from the touch panel sensor substrate 1. It suffices if it has a function of determining the coordinate position on the image display surface touched by the input person as information. Further, it is preferable that the device has a function of converting the input information into data and outputting a video including the captured information. Specifically, the control unit is composed of a personal computer, a controller IC board for position detection, and the like.

In the electronic blackboard 100 including the interactive screen 10 according to the present invention, the front projection device 3 projects information output from a control device such as a personal computer as image light onto the image display surface of the interactive screen 10 according to the above configuration. An image corresponding to this is displayed on the image display surface of the interactive screen 10. Further, the touch panel sensor substrate 1 can detect the coordinate position of the image display surface touched by the user and output the information as position information to a control unit of a personal computer or the like.

<Interactive screen>
The interactive screen 10 is an information processing and image display device in which a reflective screen 2 is installed on a touch panel sensor substrate 1, and is an interactive information processing and image display capable of inputting and outputting information such as characters and images. It is a device.

[Touch panel sensor board]
As described above, the touch panel sensor substrate 1 of the present invention adopts the projection type capacitance method. In this projection type capacitance type touch panel sensor substrate, a pair of electrodes are arranged facing each other at a predetermined distance to change the capacitance of the electrodes in the vicinity (touch position) when the fingertip approaches. It is detected by a group, that is, an X-coordinate detection electrode group and a Y-coordinate detection electrode group. Then, based on the detected information, the position coordinates of the touch position on the touch panel sensor substrate can be specified. As described above, this projection type capacitance type touch panel sensor substrate can form a touch panel capable of multi-point detection of fingertips, so-called multi-touch.

The substrate 1 for a touch panel sensor generally has a rectangular shape in a plan view, as is the case with a general flat surface shape of a blackboard, but the flat shape is not necessarily limited to such a rectangle. However, for example, the planar shape may be another shape such as a square, a circle, an ellipse, or a polygon depending on the demand.

As shown in FIGS. 1 and 2, the touch panel sensor substrate 1 has an X-coordinate detection electrode group 110 and a Y-coordinate detection electrode group 120 in order to exhibit a function as a projection type capacitance type touch panel sensor substrate. And are arranged facing each other vertically separated from each other. As shown in FIG. 1, the X-coordinate detection electrode group 110 and the Y-coordinate detection electrode group 120 may be laminated on separate support substrates 13 and support substrates 14, respectively, or may be a single support substrate. It is also possible to have a configuration in which each electrode group is formed on both sides. In any case, the X-coordinate detection electrode group 110 and the Y-coordinate detection electrode group 120 are arranged so as to be electrically insulated and to have a matrix shape as a whole in a plan view. ..

Each of the above electrode groups is composed of a plurality of electrodes arranged in parallel. As shown in FIG. 2, the X-coordinate detection electrode group 110 is formed by arranging a plurality of X-coordinate detection electrodes 11 formed on the surface of the support substrate 13 in parallel along the Y direction in a plan view. .. The same applies to the Y coordinate detection electrode group 120, and a plurality of Y coordinate detection electrodes 11 formed on the surface of the support substrate 14 along the X direction in a plan view are arranged and formed in parallel. ..

Each of these electrode groups independently detects which of the X-coordinate detection electrode group 110 and the Y-coordinate detection electrode group 120 the change in the electrostatic capacitance of the electrode is. , The position can be calculated from the intersection.

(Support board)
The support substrates 13 and 14 are substrates made of an insulating material, and a flexible film substrate or a rigid glass substrate is used. As the glass substrate, for example, non-alkali glass, soda lime glass, aluminosilicate glass and the like can be used.

When the support substrates 13 and 14 are used as a flexible film substrate, a known flexible resin film such as polyethylene terephthalate (PET), which is highly versatile and easily available, may be appropriately used. can. For example, polyester resin, polyolefin resin, (meth) acrylic resin, polyurethane resin, polyether sulfone resin, polycarbonate resin, polysulfone resin, polyether resin, polyether ketone resin, (meth). One selected from the group consisting of acronitrile-based resins and cycloolefin-based resins can be preferably used. By using the support substrates 13 and 14 as flexible film substrates, the touch panel sensor substrate 1 can be used as a flexible substrate, and the interactive screen 10 can also be provided with the required flexibility. ..

The thicknesses of the support substrates 13 and 14 may be appropriately determined according to the material from the viewpoint of having sufficient insulating properties and the balance of manufacturing costs. Generally, it is preferably in the range of 20 μm or more and 500 μm or less. If it is less than 20 μm, the mechanical strength tends to be insufficient, while if it exceeds 500 μm, the flexibility peculiar to the polymer film is lowered, and the flexibility may be insufficient.

In the touch panel sensor substrate 1, the translucency of the support substrates 13 and 14 is not an indispensable requirement. However, from the viewpoint of increasing productivity, such as to facilitate the accuracy of alignment of the formation positions of each substrate and electrode in the manufacturing process, the state of the back side of the film should be transparent enough to be visible from the front side. It is preferable to have.

(electrode)
The X-coordinate detection electrode group 110 and the Y-coordinate detection electrode group 120 are spaced apart from each other in the vertical direction, and the X-coordinate detection electrode group 110 and the Y-coordinate detection electrode group 120 are separated from each other in the vertical direction. Anything that forms a matrix-shaped sensor surface may be used. For this reason, it is preferable that the connecting direction of the electrodes constituting each electrode group, that is, the direction in which the current flows, is arranged orthogonal to each other in planar fluoroscopy.

Further, regarding the planar shape of the X-coordinate detection electrode group 110 and the Y-coordinate detection electrode group 120, as shown in FIG. 2, each of them may be composed of strip-shaped row or column electrodes, or FIG. As shown in FIG. 4, a plurality of diamond-shaped electrode pads may be connected to each other to form a row or column electrode. Alternatively, these electrode pads may be various polygonal, oval, or circular shapes other than rhombuses.

Examples of the metal forming the X-coordinate detection electrode 11 and the Y-coordinate detection electrode 12 include copper, aluminum, gold, and silver. Among these, copper can be particularly preferably used because of the balance between high conductivity and material cost.

The thickness of each coordinate detection electrode of the X coordinate detection electrode 11 and the Y coordinate detection electrode 12 may be appropriately set according to the magnitude of the withstand current required for the touch panel sensor substrate 1 and the like. However, in particular, when the support substrates 13 and 14 are used as flexible film substrates and the interactive screen 10 is of a flexible substrate type that can be wound or folded, copper is used as each coordinate detection electrode. Therefore, in order to provide sufficient mechanical strength and durability against repeated bending and bending of the interactive screen 10 and sufficiently reduce the risk of disconnection of each electrode, the X coordinate detection electrode 11 and the Y coordinate It is more preferable that the thickness of the detection electrode 12 is further increased to a thickness of 9 μm or more. On the other hand, from the viewpoint of maintaining sufficient flexibility of such a flexible substrate type interactive screen, the thickness of the X coordinate detection electrode 11 and the Y coordinate detection electrode 12 is preferably 50 μm or less.

Then, in the touch panel sensor substrate 1, the X-coordinate detection electrode 11 and the Y-coordinate detection electrode 12 have a plurality of X-coordinate detection electrodes 11 and Y-coordinate detection electrodes 12 as shown in FIGS. The openings 112 are formed by a mesh-like metal foil in which the openings 112 are dispersedly formed. Since each coordinate detection electrode is a mesh-shaped metal foil in which a large number of openings 112 are formed in this way, as described above, in a touch panel-equipped product having a large image display surface such as an electronic blackboard, each of them. Even when the coordinate detection electrode has a thickness sufficient to ensure conductivity and mechanical strength, an increase in weight can be sufficiently suppressed.

Specifically, the aperture ratio of the X-coordinate detection electrode 11 and the Y-coordinate detection electrode 12, that is, the aperture ratio of the mesh-shaped metal foil constituting each electrode may be 20% or more and 50% or less. More preferably, it is 28% or more and 50% or less. By setting the aperture ratio of each of these electrodes to 20% or more, more preferably 28% or more, the weight of the touch panel sensor substrate 1 can be maintained within a preferable range. On the other hand, if the aperture ratio exceeds 50%, the mechanical strength and durability against repeated bending and bending of the interactive screen 10 tend to be insufficient, so the aperture ratio is preferably 50% or less. Further, when the aperture ratio exceeds 50%, there is an increased risk of poor embedding of the adhesive material applied to bond each electrode and the base material laminated on the electrode, and thus from this viewpoint. The aperture ratio is preferably 50% or less.

Further, when the support substrates 13 and 14 of the touch panel sensor substrate 1 are used as a flexible film substrate and the touch panel sensor substrate is used as a flexible substrate, in particular, in order to secure the mechanical strength of each coordinate detection electrode, in order to secure the mechanical strength of each coordinate detection electrode. It will be necessary to increase their thickness. Therefore, in this case, the weight increase suppressing effect by using each coordinate detection electrode as a mesh-shaped metal sheet in which a large number of openings 112 are formed with an aperture ratio in the above range becomes more remarkable. Therefore, the touch panel sensor substrate 1 can be extremely preferably used as a touch panel sensor substrate that constitutes a flexible substrate type interactive screen from this viewpoint as well.

(Non-conducting metal foil layer)
Here, on the touch panel sensor substrate 1, as shown in FIG. 3, the X coordinate is on the surface on which the X coordinate detection electrode group 110 is formed on the support substrate 13 and in a range where the X coordinate detection electrode 11A does not exist. A non-conducting metal foil layer 111 that is separated from the detection electrode 11A by an insulating slit may be formed. The non-conducting metal foil layer 111 is preferably made of the same type of metal as the X coordinate detection electrode 11A, and is preferably formed of a mesh-like metal foil having the same shape. Similarly, as shown in FIG. 4, on the surface on which the Y coordinate detection electrode group 120 is formed on the support substrate 14, the Y coordinate detection electrode 12A is further insulated from the Y coordinate detection electrode 12A in a range where the Y coordinate detection electrode 12A does not exist. A non-conducting metal foil layer 121 isolated by a slit may be formed.

By further forming these non-conducting metal foil layers on each support substrate, the rigidity of the touch panel sensor substrate 1 is appropriately maintained while avoiding an excessive increase in the total weight and maintaining the required light weight. Can be enhanced to. According to this, it is possible to prevent the phenomenon that the image display surface is distorted due to the weight of the touch panel sensor, and it is also caused by the local occurrence of excessive bending in the portion where the metal electrode does not exist. It is possible to significantly suppress disconnection of the electrode group. In particular, when the touch panel sensor substrate is a flexible substrate type, these risk avoidance effects become more remarkable. For example, as shown in FIGS. 3 and 4, in the touch panel sensor substrate 1, the surface on which the X coordinate detection electrode group 110 of the support substrate 13 is formed and the Y coordinate detection electrode group 120 of the support substrate 14 are formed. In the case where the above-mentioned non-conducting metal foil layer is further formed in addition to the above-mentioned electrodes for detecting each coordinate, each electrode for detecting coordinates and the non-conducting metal foil layer are formed on the surface. When the ratio of the area to the surface area of each support substrate (surface coverage by the metal foil) is 90% or more, the above-mentioned opening ratio of each coordinate detection electrode and the non-conducting metal foil layer is 30% ± 5%. A degree can be given as a very preferable specific example of a substrate for a touch panel sensor for an electronic blackboard in which conductivity, mechanical strength and flexibility are improved in a well-balanced manner.

As a method for forming the pattern of each coordinate detection electrode and the non-conducting metal foil layer, a known photolithography (etching) can be used. Further, as another method for forming a pattern, plating or a printing method can be used. Examples of the conductive pattern layer using etching include those in which copper foil is laminated with an adhesive on the support substrates 13 and 14, and those in which a metal foil such as copper foil is dry-laminated on the support substrates 13 and 14 with an adhesive. Is etched into a predetermined pattern. As the adhesive for dry lamination, a known resin-based adhesive can be appropriately used. Among these resin adhesives, urethane-based, polycarbonate-based, or epoxy-based adhesives can be particularly preferably used.

Further, in addition to the above-mentioned support substrates and electrode groups, the touch panel sensor substrate 1 is further laminated with arbitrary functional layers necessary for maintaining various functions and performance levels required for the final product. It may be the one that is. Examples of such a functional layer include a hard coat layer, an antistatic layer, an antiglare layer, an antifouling layer, an antireflection layer, a high dielectric layer, an electromagnetic wave shielding layer, an adhesive layer and the like.

[Reflective screen]
In addition to the function of projecting an image, the reflective screen 2 is required to have smoothness on the surface thereof so that writing or the like can be easily performed. In addition, the reflective screen 2 also has sufficient scratch resistance to protect the surface (image display surface) from scratches and the like, and an antiglare function to reduce reflections and reflections of indoor lighting and the like. It is preferable to have. As the interactive screen of the present invention, various existing screens can be appropriately used as long as such requirements can be met at the required level according to each usage situation. For example, the "reflective screen for an interactive board" disclosed in the above "Patent Document 2" can be mentioned as a preferable specific example of a reflective screen that can be used for the interactive screen of the present invention.

As an example, a reflective screen 2 having a surface having an arithmetic mean roughness Ra (JIS B0601-2001) of 136 nm and a maximum height of Rz (JIS B0601-2001) of about 453 nm can be preferably used. With this level of surface roughness, it is possible to exert an antiglare function as an image display surface without interfering with the above-mentioned writability as an information input surface.

<Verification of effect by simulation>
The effect of the present invention was verified by producing test samples having different aperture ratios of metal portions.

(About weight reduction)
The X-coordinate detection electrode and the non-conducting metal are formed on the electrode surface side surface of the second support substrate in which the Y-coordinate detection electrode and the non-conducting metal foil layer are formed in the pattern of FIG. 3 by dry lamination and etching treatment. A plurality of types of touch panels are formed by laminating a first support substrate, which is similarly formed in the pattern of FIG. 4, with the foil layer facing the back surface of the support substrate (the side on which the electrodes are not formed) by dry etching. Test samples of the sensor substrate were manufactured as Production Examples 1 to 6.
As the support substrate, polyethylene terephthalate (PET) having a size of 1670 mm × 1070 mm and a thickness of 38 μm was used. The sheet size of this support substrate is a size assuming that an interactive screen having a diagonal length of 70 inches is formed.
Each electrode and each non-conducting metal foil layer were formed by etching a copper foil having a thickness of 12 μm.
In each of the test samples of Production Examples 1 to 6, only the etching pattern of each electrode and the non-conducting metal foil layer is changed, and only the aperture ratio of each electrode made of copper foil and the non-conducting metal foil layer is different. Six types of samples of Examples 1 to 6 were prepared separately. The aperture ratios of Production Examples 1 to 6 are as follows: Production Example 1: 0% (no opening), Production Example 2:10%, Production Example 3:25%, Production Example 4:30%, Production Example 5:45, respectively. %, Production Example 6: 60%. In Production Example 4 having an aperture ratio of 30%, it was assumed that openings having an average pore diameter of 1.1 mm were formed at a ratio of about 47 per ^{1 cm 2.} Based on this, another production example was manufactured by enlarging or reducing only the hole diameter of the opening.

As a result of the above simulation, the opening ratio was 0%, that is, in Production Example 1 in which no opening was formed in each electrode and the non-conducting metal foil layer, the total weight of the test sample was 780 g, and each electrode and the non-conducting metal. The weight of only the metal portion (copper foil) forming the foil layer was 380 g, and the weight of the metal portion composed of each electrode and the non-conducting metal foil layer accounted for about 50% of the total weight. For example, in the case of an electronic blackboard with a screen size of 70 inches, the aperture ratio of the mesh-shaped copper foil constituting the electrode and the non-conducting metal foil layer is set to 0% to 25%, thereby reducing the weight by about 100 g in calculation. Was confirmed to be possible.

(Mechanical strength and durability against bending)
Similar to the test sample of the touch panel sensor substrate, the Y coordinate detection electrode and the non-conducting metal foil layer are laminated on the same support substrate in the pattern of FIG. 3 by dry lamination and etching treatment. In the same manner as in Production Examples 1 to 6, each test sample (Production Example 1A: aperture ratio 0%, Production Example 2A: aperture ratio 10%, Production Example 3A: aperture ratio 25) in which only the aperture ratio is different. %, Production Example 4A: 30%, Production Example 5A: 45%, Production Example 6A: 60%).
For these production examples 1A, 2A, 3A, 4A, 5A, and 6A in which the metal portion is formed on the surface of the single-layer support substrate in this way, winding and opening to a cylindrical roll core material having a diameter of 1 m. And were repeated 100 times, and the mechanical strength and durability against bending were examined.

As a result of the above simulation, in Test Example 5A having an aperture ratio of 45%, slight peeling of the metal foil was observed at three places. Further, in Test Example 6A having an aperture ratio of 60%, similar peeling was observed at a plurality of locations (5 or more locations), and rupture of the electrode was observed at one location. No such peeling or tearing was observed in Production Examples 1C to 4C (opening ratio of 30% or less).

(About embedding)
Regarding Production Examples 1 to 6 above, a polyvinyl chloride film (PVC) having a thickness of 2000 μm is used as a protective member on the back surface of each of the second support substrates, and on the electrode surface of each of the first support substrates. , White polyvinyl chloride (PVC) having a thickness of 200 μm was laminated by dry lamination assuming a reflective screen, and test samples of a plurality of types of interactive screens were produced as Production Examples 1C to 6C.
In Production Examples 1C to 6C, visible irregularities were observed on the surface of the white PVC film assuming a reflective screen only in Test Example 6C having an aperture ratio of 60%. This was due to poor embedding of the adhesive layer due to the unevenness of the opening of the metal foil. In Production Examples 1C to 4C (opening ratio of 30% or less), no such surface irregularities were observed.

From the above results, the copper foil having high conductivity is formed by forming each electrode and other metal foil layers using a mesh-shaped metal foil having an aperture ratio of 25% or more and 50% or less in the substrate for a touch panel of the present invention. It was confirmed that a lightweight interactive screen can be constructed by suppressing the weight increase while maintaining good responsiveness to the detection of the touch position and maintaining the mechanical strength against bending.

1 Touch panel sensor substrate 11, 11A X coordinate detection electrode 110 X coordinate detection electrode group 111, 121 Non-conducting metal foil layer 12, 12A Y coordinate detection electrode 120 Y coordinate detection electrode group 13, 14 Support substrate 2 Reflective screen 10 Interactive screen 3 Front projection device 100 Electronic blackboard

Claims (8)

It is a projection type capacitance type touch panel sensor substrate.
A group of X-coordinate detection electrodes composed of a plurality of X-coordinate detection electrodes formed in parallel along the Y direction in a plan view on one surface of a support substrate, and
A group of Y coordinate detection electrodes composed of a plurality of Y coordinate detection electrodes formed in parallel along the X direction in a plan view on another surface of the support substrate or on one surface of the other support substrate. Prepare,
Said X coordinate detection electrodes and the Y coordinate detection electrode is made of a mesh-like metal foil in which a plurality of openings is dispersed form, the aperture ratio of the metal foil I der than 50% to 25%
Even in the range where each electrode does not exist on the surface of the support substrate or the other support substrate on which the X-coordinate detection electrode group or the Y-coordinate detection electrode group is formed, the electrodes are separated from each other by an insulating slit. A non-conducting metal foil layer made of the mesh-shaped metal foil is formed.
Substrate for touch panel sensor. The touch panel sensor substrate according to claim 1, wherein the X-coordinate detection electrode and the Y-coordinate detection electrode are both formed by connecting a plurality of electrode pads having a rectangular shape, a circular shape, or an elliptical shape. .. The substrate for a touch panel sensor according to claim 1 or 2, wherein the mesh-shaped metal foil is a copper foil. The substrate for a touch panel sensor according to any one of claims 1 to 3 , wherein the support substrate is a flexible resin film. It is an interactive screen in which a reflective screen for front projection is installed on the surface of a substrate for a projected capacitance type touch panel sensor.
The touch panel sensor substrate is
A group of X-coordinate detection electrodes composed of a plurality of X-coordinate detection electrodes formed in parallel along the Y direction in a plan view on one surface of a support substrate, and
A group of Y coordinate detection electrodes composed of a plurality of Y coordinate detection electrodes formed in parallel along the X direction in a plan view on another surface of the support substrate or on one surface of the other support substrate. Prepare,
The X-coordinate detection electrode and the Y-coordinate detection electrode are made of a mesh-shaped metal foil in which a plurality of openings are dispersedly formed, and the aperture ratio of the metal foil is 25% or more and 50% or less.
An interactive screen with a reflective screen for front projection installed on the surface of a projection-type capacitive touch panel sensor substrate. The support substrate is a flexible resin film.
The reflective screen is a large screen having a diagonal length of 30 inches or more, and can be wound on a roll when not in use.
The interactive screen according to claim 5. Even in the range where each electrode does not exist on the surface of the support substrate or the other support substrate on which the X-coordinate detection electrode group or the Y-coordinate detection electrode group is formed, the electrodes are separated from each other by an insulating slit. A non-conducting metal foil layer made of the mesh-shaped metal foil is formed.
The interactive screen according to claim 5 or 6. An electronic blackboard comprising the interactive screen and front projection apparatus according to any one of claims 5 to 7.

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