Input apparatus and input determination method

1 . An input apparatus comprising:

a base

a cover covering the base to define an inner space therebetween, the cover being configured to be subjected to a pressing operation by an operator;

an operation detection sensor configured to output an output value that varies in response to the pressing operation, the operation detection sensor being selected from a group including a capacitance sensor, an optical sensor, and a magnetic sensor;

a processor configured to determine whether the pressing operation has been performed based on the output value; and

a feel generator having a deformable contact and a pressing structure that presses and deforms the deformable contact in response to the pressing operation, the feel generator being configured to generate an operation feel to the operator,

wherein the processor is further configured to determine that the pressing operation has been completed by:

repeatedly sampling the output value of the operation detection sensor at a predetermined sampling interval;

computing, for each evaluation, a degree of temporal variation of the output value over a predetermined period based on a difference between a current sample and a prior sample taken a predetermined number of samples earlier and a corresponding time difference; and

determining that the pressing operation has been completed when the computed degree of temporal variation is within a predetermined range defined by a first threshold and a second threshold for at least a predetermined duration or a predetermined number of consecutive evaluations.

2 . The input apparatus according to claim 1 ,

wherein the deformable contact is deformable or displaceable in a pressing direction by the pressing operation, and

the feel generator is configured to generate the operation feel to the operator by being deformed under a pressing force of the pressing operation.

3 . The input apparatus according to claim 1 ,

wherein the deformable contact includes a domical portion that is inversely deformed under a predetermined pressing force,

the output value corresponds to feel characteristics, and

the feel characteristics represent characteristics of a pressing force of the pressing operation at an inverting action of the deformable contact.

4 . The input apparatus according to claim 3 ,

wherein the feel characteristics have a first pressure deformation period and an inverse period in this order, and

in response to the output value corresponding to a slope of the feel characteristics during the inverse period, the processor is configured to determine that the pressing operation has been performed.

5 . The input apparatus according to claim 4 ,

wherein the feel characteristics further have a second pressure deformation period after each of the first pressure deformation period and the inverse period, and

in response to the output value corresponding to the slope of the feel characteristics during the inverse period, the processor is configured to determine that the pressing operation has been performed.

6 . The input apparatus according to claim 4 , wherein, in response to the degree of temporal variation in the output value corresponding to a slope of the feel characteristics over the predetermined period, the processor is configured to determine that the pressing operation has been performed.

7 . The input apparatus according to claim 6 , wherein, in response to the degree of temporal variation in the output value being within a predetermined slope range of the feel characteristics during the predetermined period, the processor is configured to determine that the pressing operation has been performed.

8 . The input apparatus according to claim 7 , wherein the predetermined period and the predetermined slope range are adjustable.

9 . The input apparatus according to claim 1 , wherein a capacitance of the capacitance sensor varies according to the pressing operation.

10 . An input determination method for an input apparatus, the input apparatus including a base, a cover configured to be subjected to a pressing operation, an operation detection sensor that outputs an output value responsive to the pressing operation, a processor, and a feel generator, the input determination method comprising:

repeatedly sampling the output value at a predetermined sampling interval;

computing, for each evaluation, a degree of temporal variation of the output value over a predetermined period by comparing a current sample with a prior sample taken a predetermined number of samples earlier and a corresponding time difference; and

determining that the pressing operation has been completed when the computed degree of temporal variation is within a predetermined range between a first threshold and a second threshold for at least a predetermined duration or a predetermined number of consecutive evaluations.