A writing board set includes a writing board and a writing utensil containing ink. The writing board reflects back, when unpolarized light is incident on its surface at a viewer's side, polarized light which is parallel to a first direction and which has a degree of polarization of 95% or more. L.sub.d*, a.sub.d*, and b.sub.d* are values of L*, a*, and b* as obtained by irradiating the surface of the writing board with light that has been transmitted through a polarizing layer having a transmission axis which is orthogonal to the first direction, and measuring total reflectance through spectrophotometry. L.sub.i*, a.sub.i*, and b.sub.i* are values of L*, a*, and b* as obtained by irradiating the ink having been introduced onto a surface of a glass panel with unpolarized light, and measuring total reflectance through spectrophotometry. A color difference ΔE*.sub.ab as defined by eq. (1) is 19 or less:

ΔE*.sub.ab[(L.sub.i*−L.sub.d*).sup.2+(a.sub.i*−a.sub.d*).sup.2+(b.sub.i*−b.sub.d*).sup.2].sup.1/2  (1).

A writing board set includes a writing board and a writing utensil containing ink. The writing board reflects back, when unpolarized light is incident on its surface at a viewer's side, polarized light which is parallel to a first direction and which has a degree of polarization of 95% or more. L.sub.d*, a.sub.d*, and b.sub.d* are values of L*, a*, and b* as obtained by irradiating the surface of the writing board with light that has been transmitted through a polarizing layer having a transmission axis which is orthogonal to the first direction, and measuring total reflectance through spectrophotometry. L.sub.i*, a.sub.i*, and b.sub.i* are values of L*, a*, and b* as obtained by irradiating the ink having been introduced onto a surface of a glass panel with unpolarized light, and measuring total reflectance through spectrophotometry. A color difference ΔE*.sub.ab as defined by eq. (1) is 19 or less:

ΔE*.sub.ab[(L.sub.i*−L.sub.d*).sup.2+(a.sub.i*−a.sub.d*).sup.2+(b.sub.i*−b.sub.d*).sup.2].sup.1/2  (1).

A display board, for writing and drawing with an interchangeable whiteboard, blackboard, or electronic surface that is pressure sensitive to a marker, chalk, or stylus through the use of a pressure sensitivity matrix. A software system implemented with the pressure sensitive matrix will be able to learn from the user's natural writing behavior, natural spaces and pauses in writing, and their writing size, and with these metrics, will be able to identify or predict a long pause in the action of writing. When this pause happens, the surface physically shifts upwards through the use of two linear actuators; the shift amount being determined by the user's writing size. The board is also able to shift upwards once the writer progresses to the opposite vertical edge of the drawing surface or can shift either upwards or downwards manually with two buttons on the side of the board.

Coating compositions useable to form markable-erasable coatings and surfaces on a wide range of substrates are disclosed. The coating compositions generally include a first silane monomer, and one or both of a second silane monomer and a metal oxide. The compositions may include 40-100 wt. % of the one or more silane monomers and up to 60 wt. % of the metal oxide based on the total solids weight in the coating composition, and an acid catalyst and a sufficient amount of water to form hydrolysates of the silane monomers. The first silane monomer may include a trialkoxy functional silane, and the second silane monomer may include a tetraalkoxy silane. The coating composition may be provided as a two-component system that does not cure to form a hardened coating until the two components are mixed. Articles coated with the coating, and methods of forming markable-erasable articles are also disclosed.

A writing board holder adapted for use with various writing boards and writing implements, incorporating a design attractive to children for interactive play. The writing board holder comprises at least one support post with an attached writing board, and appendages which can be used with writing and erasing implements to draw on the board and clean the board.

A writing board holder adapted for use with various writing boards and writing implements, incorporating a design attractive to children for interactive play. The writing board holder comprises at least one support post with an attached writing board, and appendages which can be used with writing and erasing implements to draw on the board and clean the board.

According one embodiment, there is provided an information display apparatus including a processor, the processing being configured to display a character string including a plurality of keywords on a display; to detect a kind of an association operation when the processor accepts designation by a user operation of any one of the keywords displayed on the display, and accepts the association operation of related information corresponding to the designated keyword; and to set a problem-setting method with respect to the designated keyword, the problem-setting method corresponding to the detected kind of the association operation.

The present disclosure relates to an electronic blackboard, including a liquid crystal display panel and at least one metal panel, wherein the liquid crystal display panel includes a liquid crystal screen, and a surface of the liquid crystal screen is provided with a glass board; the metal panel comprises a first metal sheet, a supporting board and a second metal sheet, with same being sequentially arranged; and a surface of the first metal sheet is coated with a coating for writing on with a piece of chalk or a stylus pen.

The present disclosure relates to an electronic blackboard, including a liquid crystal display panel and at least one metal panel, wherein the liquid crystal display panel includes a liquid crystal screen, and a surface of the liquid crystal screen is provided with a glass board; the metal panel comprises a first metal sheet, a supporting board and a second metal sheet, with same being sequentially arranged; and a surface of the first metal sheet is coated with a coating for writing on with a piece of chalk or a stylus pen.

The present invention discloses a using method of a rewritable board. It comprises applying or removing a fluid on the rewritable board for writing repeatedly, wherein the rewritable board is an aluminum based material sequentially having a porous aluminum oxide layer and a metal layer thereon, and wherein the porous aluminum oxide layer has a porosity ranging from 10% to 80%.