Control apparatus, control method, and ophthalmologic apparatus including the control apparatus

A joystick apparatus for controlling a control target, comprising:

• an operation stick;
• a detection unit for repeatedly detecting a rotation direction and a rotation speed of a rotational member provided to the operation stick;
• and
• a control unit for outputting a control value corresponding to the rotation direction and the rotation speed that are repeatedly detected,
• wherein when an amount of decrease in a rotation speed detected at a first timing with respect to a rotation speed detected at a second timing preceding the first timing is larger than a threshold value, the control unit restricts a decrease in the control value per unit time according to the decrease in the rotation speed detected at the first timing.

A control method for an apparatus including a joystick for controlling a control target, the control method comprising:

• repeatedly detecting a rotation amount of a rotational member provided to the joystick;
• outputting a control value corresponding to the rotation amount according to the detecting;
• determining whether or not a decrease in the rotation amount, in which an amount of decrease in the control value per unit time exceeds a threshold value, has occurred;
• outputting, when it is determined that the decrease in the rotation amount does not occur, the control value so that a sum of the control values to be output becomes a first value corresponding to a sum of the detected rotation amounts;
• and
• restricting, when it is determined that the decrease in the rotation amount has occurred, the amount of decrease in the control value per unit time to a value that avoids exceeding the threshold value to output the control value so that the sum of the control values becomes larger than the first value.

An ophthalmologic apparatus, comprising:

• detection means for detecting a rotation speed and a rotation direction of a rotational member provided to a joystick at predetermined sampling intervals;
• drive means for electrically performing vertical movement of an optical system for imaging, observation, and measurement of an eye to be inspected;
• control means for controlling the drive means at a speed and in a direction respectively corresponding to the rotation speed and the rotation direction of the rotational member that are detected at a current sampling by the detection means;
• storage means for storing the rotation speed and the rotation direction of the rotational member that are detected by the detection means;
• and
• subtraction means for calculating, when the rotation direction at a previous sampling that is stored in the storage means and the rotation direction at the current sampling are the same, or when the rotation speed is zero, a rotation speed obtained by subtracting a predetermined value from the rotation speed at the previous sampling that is stored in the storage means,
• wherein the control means compares the rotation speed obtained through the subtraction to the rotation speed at the current sampling, and sets a higher speed as the rotation speed at the current sampling to be used for controlling the drive means.

An ophthalmologic apparatus, comprising:

• detection means for detecting a rotation speed and a rotation direction of a rotational member provided to a joystick at predetermined sampling intervals;
• drive means for electrically performing vertical movement of an optical system for imaging, observation, and measurement of an eye to be inspected;
• control means for controlling the drive means at a speed and in a direction respectively corresponding to the rotation speed and the rotation direction of the rotational member that are detected at a current sampling by the detection means;
• storage means for storing the rotation speed and the rotation direction of the rotational member that are detected by the detection means, and further storing an upper limit rotation speed corresponding to an upper limit of a rotation speed of the drive means, and a difference between the upper limit rotation speed and the rotation speed in a case where the detected rotation speed of the rotational member exceeds the upper limit rotation speed;
• and
• subtraction means for subtracting the upper limit rotation speed from the rotation speed to calculate the difference,
• wherein when a current rotation speed of the rotational member exceeds the upper limit rotation speed, the control means sums up the differences stored in the storage means to calculate a summed speed, which is stored in the storage means, and sets the upper limit rotation speed as the current rotation speed to be used for controlling the drive means, and
• wherein when the rotation speed is lower than the upper limit rotation speed, the control means compares the summed speed to a current difference obtained by subtracting the current rotation speed from the upper limit rotation speed stored in the storage means, subtracts a lower rotation speed from the summed speed to obtain a new summed speed, which is stored in the storage means, and sets a speed obtained by adding the lower rotation speed to the current rotation speed, as the current rotation speed to be used for controlling the drive means.