JPH0125090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a cursor for a free cursor type digitizer that reduces errors in inputting coordinate values of figures.

Generally, free cursor type digitizers are used as graphic input devices in CAD/CAM systems, which have recently been increasingly introduced with the aim of increasing the efficiency and quality of design and manufacturing. This device is
It consists of a flat digitizing surface, a coordinate point detection and pointing device called a cursor, and a control device. This cursor is connected to a control device by a cable, and its size is such that an operator can grasp it with his hand and move it freely over the digitizing surface.

FIG. 1 is a perspective view of an example of this type of cursor. In the figure, 1 is a transparent plastic plate,
A circular hole is made in a part of it, and a cross mark 2 is written on another thin transparent plastic on the digitizing surface side. 3 and 3' are push button switches for specifying coordinate points and for other commands.

To obtain the coordinate values of a figure, touch the cursor surface 5 of this transparent plastic plate 1 to the digitizing surface, align the cross mark 2 with a predetermined position on the figure, and then press the push button switch 3 for specifying coordinate points. is input. At this time, a buzzer sounds to notify the operator that the coordinate values of the figure have been input into the system.

In a conventional cursor, the signal from the coordinate point indicating push button switch 3 is directly supplied to the digitizer control device through the cable 4, and the digitizer control device detects the closed state of the switch signal, and at that point the cursor is The coordinate values on the digitized surface indicated by were sent to the system.

However, as soon as this pushbutton switch 3 is pressed, the coordinate values detected by the cursor are input. The disadvantage is that when you move the figure, the exact coordinates of the figure are not entered.

Based on the above considerations, the purpose of this invention is to
To provide a digitizer cursor which invalidates the input when the cursor is moved before pressing a coordinate point designation push button so that erroneous coordinate values are not input.

The structure of the present invention is that, in a free cursor type digitizer cursor in which a cursor is moved over a figure and the position of the cursor is digitized and input into a computer, a coordinate point indicating switch is pressed when inputting the coordinate points of the figure. and a contact detection switch connected in series with the coordinate point indicating switch and provided on a contact surface of the cursor with the digitizing surface to detect the contact, when the cursor comes into contact with the digitizing surface. The present invention is characterized in that the coordinate points can be input.

This invention will be explained in detail below using the drawings.

FIG. 2 is a perspective view of an embodiment of the invention. This embodiment is characterized in that a contact detection switch 6 is provided for detecting contact between the cursor surface 5 and the digitizing surface. This switch 6 is configured so that when the cursor is moved, the contact detection switch 6 becomes open. Therefore, even if you press pushbutton switch 3 for specifying coordinate points while moving the cursor,
Since the contact detection switch 6 is in an open state, the switch circuit is in an open state and coordinate values are not sent from the digitizer to the system. Therefore, while the cursor is moving, specifying coordinate points is prohibited, and the buzzer notifying the operator of inputting coordinate values does not sound, so the operator must input coordinate values again, thereby ensuring accuracy. coordinate values are always input.

Note that the contact detection switch 6 is connected to the cursor surface 5 where the contact detector 10 contacts the digitizing surface.
This contact detector 1
When 0 comes into contact with the digitizing surface, force is applied to the contact detector 10 as a reaction. This applies pressure to the pressure-sensitive conductive rubber sheet 9 inserted between the contact detector 10 and the cursor body, and this pressure significantly reduces the volume resistivity of the pressure-sensitive conductive rubber sheet.

FIG. 3 is a characteristic diagram showing an example of the relationship between pressure and volume resistivity of a pressure-sensitive conductive rubber sheet. In the figure, state B with a pressure of approximately 0.2 kg is the state in which the cursor is in contact with the digitizing surface, and the pressure is 0.
State A corresponds to the state in which the cursor is removed from the digitizing surface. For example, if the thickness of the pressure-sensitive conductive rubber sheet is 1 mm and the area to which pressure is applied is 1 cm ² , then in state B, where a pressure of 200 g/cm ² is applied, its resistance value is approximately 30 Ω, and in state A, it is 100 M Ω.
becomes. The compression ratio of this pressure-sensitive conductive rubber sheet is
At a pressure of ^about 200g/cm2, it is less than 2%, and at a thickness of 1mm.
It is 0.02mm. Therefore, when the cursor is moved slightly away from the digitizing surface, the contact detection switch becomes open. When this cursor is in contact with the digitizing surface, a sufficient pressure of 200 g can be obtained, so the resistance value of the contact detection switch 6 is several tens of Ω.
The result is a closed circuit state. Note that while the cursor is moving, the value is approximately 100MΩ, so it is in an open circuit state.

FIG. 4 is a cross-sectional view XX' of FIG. 2. In FIG. 4, the contact detector 10 is located at a distance l ₁ from the cursor body 11.
Considering the compression ratio of the pressure-sensitive conductive rubber sheet, this protrusion value is sufficient to be 0.5 mm or less if the cursor surface 5 is flat.

Figures 5a and b are enlarged views of part A in Figure 4.
The differences between FIGS. 5a and 5b are due to differences in switch configuration. In FIG. 5a, 7 and 8 are electrodes on the contact detector and the cursor body, respectively, and their shapes are concentric circles with no electrode in the center. The shape of the pressure-sensitive conductive rubber sheet 9 is also concentric with the electrodes, and the lead wires 12 and 12' of the switches from the respective electrodes 7 and 8 are connected in series to the coordinate point indicating push button switch 6. Ru.

Figure 5b shows a structure in which the pressure-sensitive conductive rubber sheet is divided into two parts, 9 and 9' and the cursor body side electrodes are 8 and 8', and the contact detector side electrode 7 is made of two pressure-sensitive conductive rubber sheets. 9 and 9'.
In this case, there is an advantage that the lead lines 12, 12' can be drawn out from the electrodes 8, 8' of the cursor body.

As is clear from the above explanation, by connecting the switch for detecting contact between the digitizing surface and the cursor in series with the switch for specifying the coordinate point of the cursor for free cursor type digitizer, the push button switch for specifying the coordinate point can be activated when the cursor moves. Even if the contact detection switch is pressed, the closed state of the coordinate point indicating switch cannot be detected by the digitizer control device because the contact detection switch is in the open state, and erroneous coordinate values will not be input into the system. Therefore, since accurate coordinate values are always input, there is an effect that even a large number of graphic coordinate values can be input accurately.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional cursor, Fig. 2 is a perspective view showing an embodiment of the present invention, Fig. 3 is a characteristic diagram of a pressure-sensitive conductive rubber sheet, and Fig. 4 is the contact detection shown in Fig. 2. cross-sectional view of the switch, Figures 5a and b are similar to Figure 4A.
It is an enlarged view of the part. In the figure: 1...the transparent plastic plate of the cursor, 2...
...Cross mark, 3, 3'...Push button switch,
4... Cable, 5... Cursor surface in contact with the digitizing surface, 7... Electrode on the surface of the contact detector,
8, 8'...Electrode on the surface of the cursor, 9,9'...Pressure-sensitive conductive sheet, 10...Touch detector, 11...
The cursor body, 12, 12'... are lead lines from the electrodes.

Claims (1)

[Claims] 1. In a free cursor type digitizer cursor that moves a cursor over a figure and digitizes the position of the cursor and inputs it to the computer, there is a switch for indicating the coordinate point that is pressed when inputting the coordinate point of the figure, and this coordinate point. a contact detection switch connected in series with the instruction switch and provided on a contact surface of the cursor with the digitized surface to detect the contact; A digitizer cursor that allows input.