Principle Of Sensor Emission & Reception - Yamaha Disklavier MX100A Product Handbook

Principle of Sensor Emission & Reception
The Key Emission sheet incorporates 12 LEDs, where each LED is assigned to a different key in the scale: from
A to G#. The Key Receive sheet incorporates 8 photoreceptors, one for each octave. The combination of LED and
photoreceptor uniquely identifies each key on the keyboard.
Emission & Reception Design
The 12 LEDs fire sequentially, from A to G#. (They do not fire simultaneously.) The receiving side detects the
octave, thereby uniquely identifying the key.
Example: Detection of Key 25A
Emission Sheet
LED
Sequential
A
firing
A#
B
C
C#
D
D#
E
F
F#
G
G#
1A 2A# 3B 4C 5C#
1A 2A# 3B 4C 5C#
13A 14A# 15B 16C 17C# 18D 19D# 20E
13A 14A# 15B 16C 17C# 18D 19D# 20E
25A 26A# 27B 28C 29C# 30D 31D# 32E
25A 26A# 27B 28C 29C# 30D 31D# 32E
37A 38A# 39B 40C 41C# 42D 43D# 44E
37A 38A# 39B 40C 41C# 42D 43D# 44E
49A 50A# 51B 52C 53C# 54D 55D# 56E
49A 50A# 51B 52C 53C# 54D 55D# 56E
61A 62A# 63B 64C 65C# 66D 67D# 68E
61A 62A# 63B 64C 65C# 66D 67D# 68E
73A 74A# 75B 76C 77C# 78D 79D# 80E
73A 74A# 75B 76C 77C# 78D 79D# 80E
85A 86A# 87B 88C
85A 86A# 87B 88C
Sensor
6D 7D# 8E 9F 10F# 11G 12G#
6D 7D# 8E 9F 10F# 11G 12G#
21F 22F# 23G 24G#
21F 22F# 23G 24G#
33F 34F# 35G 36G#
33F 34F# 35G 36G#
45F 46F# 47G 48G#
45F 46F# 47G 48G#
57F 58F# 59G 60G#
57F 58F# 59G 60G#
69F 70F# 71G 72G#
69F 70F# 71G 72G#
81F 82F# 83G 84G#
81F 82F# 83G 84G#
I-33
Receive Sheet
1
2
3
4
5
6
7
8