Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
244 words
In a coordinates input apparatus having a tablet (1) constituting a coordinates input section, a plurality of position designating devices (2) of different types such as stylus pens, and a position detecting circuit (3) adapted to drive said tablet and detect positions at which coordinates are input by said position designating devices, a system for detecting the status of said position designating devices comprising: an antenna coil (13) disposed around a coordinates input range (14) of said tablet; and a tuning circuit (22) disposed in each of said position designating devices, said tuning circuit including a coil (222) and capacitors (223,224) which constitute a set and being adapted to transmit radio waves in response to an external signal at an individual frequency determined in accordance with the type of the corresponding position designating device, wherein an AC signal (B) having frequencies which are identical to the individual frequencies of said tuning circuits is intermittently and sequentially applied to said antenna coil so that radio waves are transmitted by said antenna coil, and, when the transmission of said radio waves is suspended, signals (C) generated by said tuning circuits in response to said radio waves are received by said antenna coil, thereby enabling detection of the position and operating status of said position designating devices, and the correspondence of the frequencies of the received signals with the types of said position designating devices is determined to differentiate between the types of said position designating devices.
Claim 2
Dependent Claim
244 words
In a coordinates input apparatus having a tablet (1) constituting a coordinates input section, a plurality of position designating devices (2) of different types such as stylus pens, and a position detecting circuit (3) adapted to drive said tablet and detect positions at which coordinates are input by said position designating devices, a system for detecting the status of said position designating devices comprising: an antenna coil (13) disposed around a coordinates input range (14) of said tablet; and a tuning circuit (22) disposed in each of said position designating devices, said tuning circuit including a coil (222) and capacitors (223,224) which constitute a set and being adapted to transmit radio waves in response to an external signal at an individual frequency determined in accordance with the type of the corresponding position designating device, wherein an AC signal (B) having frequencies which are identical to the individual frequencies of said tuning circuits is intermittently and sequentially applied to said antenna coil so that radio waves are transmitted by said antenna coil, and, when the transmission of said radio waves is suspended, signals (C) generated by said tuning circuits in response to said radio waves are received by said antenna coil, thereby enabling detection of the position and operating status of said position designating devices, and the correspondence of the frequencies of the received signals with the types of said position designating devices is determined to differentiate between the types of said position designating devices.
Claim 3
Dependent Claim
62 words
A system according to claim 1, further comprising a switch (221) disposed in each of said tuning circuits (22) for turning on or off the connection between said coil and said capacitors, wherein, when it is required to designate only a position at which coordinates are to be input, said position designating devices are used by turning on or off said switches.
Claim 4
Dependent Claim
46 words
A system according to claim 1, wherein said tablet further comprises a casing (11) made of a non-metallic material such as a synthetic resin, and a tablet body (12), in addition to said antenna coil (13), said casing accomodating said tablet body and said antenna coil.
Claim 5
Dependent Claim
28 words
A system according to claim 1, wherein each of said position designating devices further comprises a magnetism generator (21) for designating positions, in addition to said tuning circuit.
Claim 6
Dependent Claim
38 words
A system according to claim 1, wherein said antenna coil (13) comprises a conductive wire provided with an insulation coating such as polyvinyl chloride, said conductive wire being disposed around a coordinates input range (14) of said tablet.
Claim 7
Dependent Claim
15 words
A system according to claim 1, wherein said tuning circuit has a variable capacitor (224).