JPS62165235A - Blackboard eraser for input of electronic blackboard - Google Patents

Abstract

PURPOSE:To transmit a required signal simultaneously with erasing of a character by providing an oscillator, which is directed forward and capable of oscillating high frequency oscillating waves having a natural frequency, in the peripheral part surrounding an eraser body in the front part of a case body and connecting the oscillator to an oscillating circuit. CONSTITUTION:An oscillating circuit 17 and a cell 18 like a dry cell are stored in a case body 15, and an oscillator 21 is excited, and the case body 15 is formed into an angular cylinder to surround an erasing felt 16, and high frequency oscillating waves are propagated in air. Detecting circuits 33 are attached to both ends of a high polymer piezoelectric sheet 1, and potentials VL and VR generated in the left and the right are calculated. When the distortion occurrence point of a resistance film 3 is defined as a variable (x), coordinates (x) of the distortion occurrence point at a time t = to are obtained in accordance with VR(to) and VL(to), and the difference between respective signals of counter electrodes 5x and 5x is divided by the sum value to obtain coordinates (x) as displacement from the center point of the resistance film 3. A signal which erases the same characters reproduced on a display device installed in a separate position is issued simultaneously with erase of characters on an electronic blackboard 7 by an eraser 14. Thus, position information of the erase point is given to the electronic blackboard 7 in the state of oscillation distortion while erasing characters.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a blackboard eraser for inputting electronic blackboards that can erase characters written on an electronic blackboard and at the same time give an electric signal according to the erasing pattern to the electronic blackboard. Regarding.

(Conventional technology) +1 for technology that has recently been put into practical use! There are video conferencing systems that use telephone lines, but there is an electronic blackboard that is indispensable for meetings with a large number of people.

In other words, characters, pictures, etc. drawn on an electronic blackboard can be converted into electrical signals that can be transmitted and recorded, and a television imaging system can be used in conjunction with a reception system: d. It is a convenient device.

As an example of this electronic blackboard, there is a publicly known one recorded in the Nikkan Kogyo Shimbun published on Friday, March 16, 1980, and this blackboard was created by enlarging the drawing pad of the sketchphone that had already been developed. /IM has a structure in which one parallel electrode sheet is stacked so that fl and ffi are perpendicular to each other, and a pressure-sensitive rubber sheet is sandwiched between them. On the x and y coordinate axes where h is perpendicular to
The 4 ki was converted into a number, and writing implements such as felt-tip pens were used instead.

(Point 1j before the invention is finalized) However, since the conventional blackboard (b) has only a position recognition function based on pressure sensitivity, it is difficult to move the hand as shown schematically in Figure 10 (b). If pressure is applied to the same location, such as erasing while pressing the contact, the electric signal converter recognizes the center of gravity of the two-point contact as the contact point, causing a problem of malfunction.

Also, as shown in Figure 10 (b), when two or more people erase the characters written on the blackboard at the same time, the center of gravity of the multi-point contact will be mistakenly judged to be the contact point. .

On the other hand, as shown in Figure 11 on the blackboard, the color of the pen is displayed by operating six color recognition switches installed directly below the hole in the felt-tip pen stand 6η.
Erasing characters only works when all color recognition switches G (a) are closed. For example, when a black pen (aaB) is pulled out, the corresponding recognition switch is opened. If it is, the part erased with the blackboard eraser will not be erased, and the color recognition circuit of the 4-child blackboard will transmit a black sign.

With this method, it is clear that the felt-tip pens must be inserted into the holes in the stand 61) in order to function properly, which requires careful attention and is cumbersome. There are many practical problems, such as not being able to simultaneously write and erase with the left hand.

In view of these various problems, the present invention has been made, and it is possible to use a blackboard eraser not only to specify the erasing position but also to simultaneously write one word in two places indicating that the erasing operation is being performed. By providing an output function, erasing information can be accurately transmitted using an electronic blackboard as a medium, and characters can be erased simultaneously at multiple distant locations, making it suitable for a wide range of applications such as video conferencing systems. That is.

(Means for Solving the Problems) As is clear from the drawings, the present invention includes a sheet (2) made of a piezoelectric polymer material having piezoelectricity that can be converted into an electric signal when high frequency vibration is applied. This is a blackboard eraser for inputting an electronic blackboard (7) that generates high-frequency vibrations at the same time as the character 1 and the portrait. Eraser α
Q is mounted so as to protrude forward, and vibration capable of oscillating a high-frequency vibration wave of a natural frequency in at least four corners of the peripheral part surrounding the eraser body α6 in the front part of the case body αυ, directed forward. In addition to providing the child 3η, the oscillation circuit α
The configuration is such that it is read directly from η.

(Function) The blackboard eraser of the present invention allows the erased position to be identified by the level of vibration distortion caused by high-frequency vibration, and it is also possible to identify that the erased character is being erased at the unique 7 wave number level.

Therefore, by performing the same operation as when erasing a normal blackboard, it is possible to erase the characters and transmit the required signal at the same time.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the main part of the blackboard eraser 14) according to the present invention, which has a truncated pyramid shape (the front part of the case body).
A letter eraser 06, for example, a cube-shaped letter eraser felt, is attached to the central part of the figure (bottom position in the figure) with a part protruding forward, and a portion surrounding the letter eraser α1 in the front peripheral area is A rectangular frame-shaped vibrator ■υ, such as a high-frequency vibration wave vibrator, is housed.

On the other hand, an oscillation circuit αη and a battery α, for example, a dry battery, are housed inside the case body aυ, and the case body αQ
(There is a switch (A) in the same place,
An oscillation circuit αη, a dry cell 0811 vibrator 12), and a switch (A) constitute a high-frequency oscillation device.While the switch (A) is turned on, the vibrator CI) vibrates and the eraser felt α It is a rectangular cylinder that surrounds the haiku, and is designed to transmit high-frequency vibration waves through the air.

The vibrator r2]) supports, for example, a frame-shaped polymeric pressure film @ on the inner and outer side edges of the film support 2, and also supports the film 1'2.
It has a structure in which a protective net μs is stretched in front of the polymer piezoelectric film 3, and it is possible to vibrate this polymer piezoelectric film by applying a high frequency output from an oscillation circuit.

The blackboard eraser +141 with the structure described above is made by holding the case body with your fingers, and at the same time as you hold the case, the switch handle is turned on by contact with your fingers, and in this state, the eraser felt α6 is pressed against the electronic blackboard (7). When they touch each other and perform the erasing operation, the vibration waves from the vibrator ■υ form a rectangular tube shape around the erasing felt Qf9 and propagate through the air to the surface of the electronic blackboard (7) in front of the electronic blackboard (7), causing the polymer piezoelectric The sheet (2) made of the material is locally vibrated in the shape of a square frame.

In addition to arranging the oscillators 21) over the entire circumference, independent small oscillators 21) may be arranged at each of the four corners so as to vibrate all at once.

In addition, in the figure (IQ is a lid for battery replacement.

The signal processing circuit supporting the Shigeko blackboard (7) whose characters and pictures are erased using the blackboard eraser will be briefly explained with reference to FIG. 2 and subsequent drawings.

The electronic blackboard (7) uses a polymer pressure sheet (1) as a substrate (6)
or the like, directly or via a rubber sheet, and if necessary, a colored protective film is laminated on the surface to form a rectangular plate, and the plate is finished, for example, in white.

A polymeric piezoelectric sheet (1) is sandwiched between a sheet (2) made of a polymeric piezoelectric material such as polyvinylidene fluoride (PVDF) and coated on both sides with a resistive thin film (hereinafter referred to as a resistance film) (3) made of a carbon-containing polymer, for example. Films and metal thin films (
(hereinafter referred to as metal film) (4) For example, it is a laminate formed by adhering aluminum foil to each other, and furthermore, the sheet (2) can be subjected to a bulking process by applying a high DC voltage of 1 pressure between both surfaces. Therefore, the sheet (2) made of the polymeric piezoelectric material becomes piezoelectric due to the polarization treatment.

In addition to PVDF, any polymeric material that exhibits piezoelectricity can be used as the polymeric piezoelectric material.On the other hand, the resistive film (3) is made by uniformly dispersing carbon particles in the fluorine fiber. Examples of rows include those made into thin sheets.

The polymer piezoelectric sheet (1) configured in this way is a resistive film (3).
Strip-shaped electrodes (5 At the same time, electrodes (5y) and (5y) having the same structure as the electrodes (5X) and (5X) are arranged on both end sides in the y direction (vertical direction in FIG. 2) that is perpendicular to the X direction. .

The above electrode (5X), (5X) and the electrode (5Y), (5
It goes without saying that the electrodes (5x), (5x), (5y), and
(5y), make each conducting wire (11) to (14) read directly, and connect the conducting wires C11), C12') to the X coordinate detection line (
8), and connect the X coordinate detection line (9) to the conductors (la) and (J?4), but both lines (8).

Since (9) has the same structure, the following is the X coordinate detection line (8)
I will explain about it.

A current/voltage converter (IOX) is connected to the end of each conductor (4), (h), respectively, and a plurality of frequency discrimination circuits (a), (4) are connected to each output terminal thereof. , (7)... are branch-connected, and the adders (IIX), (IIX), (II
X) -... and subtractor (12X), (12X), (
12X)... are connected in parallel, and the output terminals of adders (1lx), (11x), ' (1tx)... and subtracters (12X), (12X), (12X) are connected in parallel.
)...'s output terminal as a divider (13X), (13X)
, (13X) is connected to both input terminals,
The frequency discrimination circuit (4), m, i... has a frequency (
The frequency discriminator circuit (1) outputs only the electric signal in the first frequency band having the cutoff center frequency with the cutoff center frequency (fo) as a P wave,
) as the cutoff center frequency, the frequency discriminator circuit outputs only the electric signal in the second frequency band adjacent to the first frequency band as 7P waves, and in the same way, (f
o'') as the cutoff center frequency, and the frequency discrimination circuit (7) is configured to output only the electrical signal of the third frequency band adjacent to the second frequency loss band as a P wave.

Therefore, the X-coordinate detection line (8) transmits both pressure signals of the 7E flow/l pressure converter (10x) and (10x) to one of the frequency discrimination circuits (a), (a), and (7). 4 is a signal having a frequency of 10,000 in the first frequency band, the subtracter (12x) subtracts the signal, and this value is added to the adder (12x).
IIX) calculates a series of calculations such that the sum of the numbers is divided by the calculation unit (13x) as the number of pitches, and the calculated leisure value is output.

(These addition, subtraction, and division operations) γ can be realized with an analog circuit, but for example, x can be realized as a pole (5 The signal may be converted into a digital signal by an A/D converter, input into a microcomputer, and processed by software.

Note that the metal film (4) is for grounding.

Next, on the electronic blackboard (7), when the rectangular Karamolecular Pressure 'α sheet (1) vibrates in the thickness direction due to the local sub-frequency driving force (see Fig. 6), the limbs ilH
1 to detect the x and y coordinates on the resistive film (3) for
The process will be explained as follows.

First, since the terms of the X-axis and y-axis are the same, they will be considered in one dimension in the X-axis direction.

As shown in Figure 6, when a pressure/resistance material is subjected to high frequency vibration and strain in the thickness direction due to the vibration is applied, polarization occurs and the terminal (a)
) and (b).

Figure 7 shows the four voltages generated between terminals (a) and (b) on the vertical axis, with each hour being the full force.As is clear from this diagram, the state shown in Figure 6 is When is replaced with a real equivalent circuit, it becomes as shown in FIG.

In other words, the part where vibrational strain occurs has a charge (Q
o) is represented by a capacitor with

Since the resistance of the resistive film (3) is uniformly distributed over the rectangular surface, the resistance value on the right side of the strain generation point (in Figure 6) is R.
The resistance values on the left side of R1 are respectively expressed as RL.

Now, as shown in Fig. 8, projection circuits q9 are attached to both ends of the polymer piezoelectric sheet (1), respectively, and the potentials VL and V generated on the left and right sides are
Calculate R.

In this case, the e terminal of the operational amplifier <o,p) is grounded in the same way as the metal film (4).

...(b) vR(t)=-1v(t) If the strain generation point of the resistive film (3) is the variable X, then RL,
RR is equivalently expressed as a slide resistance as shown in FIG.

RL RR""2xRo...'(c) 2n here
From o = RI, + RR - (c), from this equation (e), at a certain time 1 = 18, the coordinates (X) of the strain generation point are Vrt (to), VL (t
o).

In other words, equation (e) is the opposite Rh (5X), (5X)
Each signal (opposite voltage 'Jj= (5Y), (5
The same applies to Y)), by dividing the difference by the sum value, the X coordinate (X coordinate) is obtained as the displacement from the center point of the resistive film (3).

As is clear from the above explanation, when a blackboard eraser with oscillation directionality is brought into contact with the electronic blackboard (7) whose element is the 1st episode molecular printing sheet (1) to perform erasing operation. , Electronic blackboard (7)) Since vibration distortion occurs sequentially in a pattern corresponding to the movement of the electronic blackboard (7), the electronic blackboard (7) side continuously transmits the electric signal of the It is possible to simultaneously distinguish the oscillation frequency, transmit it, and record it as information.

In this case, if the blackboard eraser 114) is caused to oscillate at a specific frequency, it is possible to identify and output an erase signal by discriminating the frequency.

By the way, the position where the electronic blackboard (7) detects the strain/assistance corresponds to the center of gravity (center) of the eraser felt head, so the X coordinate detection line (8) and the X coordinate detection line (9)
On the circuit side that processes the signal from the center of gravity, it is determined in advance at the design stage that the surface coordinates of the range corresponding to the contact surface of the eraser felt U1 can be obtained as a signal based on the center of gravity position, and the surface coordinates are For example, the information written on the electronic blackboard (7) corresponding to the white board is displayed on a display device at a separate remote location by outputting the information written on the white board as a signal to switch to the same white symbol as the white board (7). A signal for erasing the corresponding character can be independently extracted.

In this way, while erasing characters on the electronic blackboard (7) using the blackboard eraser 04), a signal for erasing the same characters reproduced on a display device at a remote location is simultaneously issued, thereby achieving the desired purpose.

In addition, when using multiple blackboard erasers 04), by oscillating unique high-frequency vibration waves with different frequencies, it is possible to erase characters reliably even when erasing multiple locations at the same time. is possible.

(Effects of the Invention) The present invention has the configuration and operation described above, and the effects are listed below.

(a) Blackboard eraser α of the present invention α Kiku is an erasable eraser σQ
and an oscillator Qυ that can oscillate a high-frequency vibration wave with a natural frequency in the direction surrounding the letter eraser α→.
While erasing characters, the location information of the erasing point can be given to the electronic whiteboard (7) in a state of vibration distortion, and it is possible to make the display device express erasing characters of the same pattern at the same time.

(b) In addition, since the blackboard eraser 04) itself is made to recognize that it is erasing by the frequency level that it oscillates, even if you write with your right hand and erase with your left hand at the same time, there will be no confusion and it will be accurate. It is possible to transmit erasure information to

(c) Since the blackboard eraser of the present invention can be handled in the same manner as a conventional general blackboard eraser, there are no strict restrictions on practical use, and it is extremely convenient.

[Brief explanation of drawings]

FIG. 1 is a front view schematically showing the structure of an example of the present invention, FIG. 2 is a developed view showing the structure of an electronic blackboard used in combination with the example of the present invention, and FIGS. A plan view of a polymer piezoelectric sheet forming an element of the electronic blackboard shown in the figure, a sectional view and a bottom view taken along the line A-A in FIG. Each explanatory diagram showing, Figure 10 (a)
, (+=) and FIG. 11 are schematic explanatory diagrams of a conventional electronic blackboard. (2)...Sheet, (7)...Electronic blackboard,
04)...Blackboard eraser, αυ...Case body,
αQ... letter eraser, αη... oscillation circuit, (1
81...Battery, ■υ...Vibrator. Region 1 Figure 3 Figure 6 Figure 8 Figure 9

Claims (1)

[Claims] 1. An electronic blackboard in which high-frequency vibrations are applied to an electronic blackboard (7) on which a sheet (2) made of a piezoelectric polymer material having piezoelectricity that can be converted into an electric signal when high-frequency vibrations are applied is attached to the electronic blackboard (7) at the same time as erasing characters. The case body (1) is a blackboard eraser for input and contains an oscillation circuit (17) and a battery (18).
A letter eraser (16) is attached to the front part of the case main body (15) so as to protrude forward.
A vibrator (21) capable of oscillating a high-frequency vibration wave of a natural frequency in a forward direction is provided in a peripheral portion surrounding the vibrator (21), and the vibrator (21) is connected to the oscillation circuit (17). A blackboard eraser for inputting information on an electronic blackboard.