Image pickup apparatus, lens unit and control method therefor wherein focus driving prediction is calculated and sent from lens unit to camera controller

A lens unit detachably mountable to an image pickup apparatus having an image sensor operable to perform charge accumulation and generate an image signal, the lens unit comprising:

• an image taking optical system including a focus lens;
• and
• a lens controller configured to receive a drive instruction for the focus lens from the image pickup apparatus and to control drive of the focus lens on a basis of the drive instruction, said drive instruction is generated on a basis of a focus signal generated by using the image signal,
• wherein a reciprocating operation of the focus lens is performed for determining an in-focus direction before a peak-climbing operation, to drive the focus lens in a direction in which the focus signal is increased, or determining an in-focus state after the peak-climbing operation,
• wherein when the reciprocating operation of the focus lens is performed, the lens controller is configured to receive information relating to a predetermined timing and the drive instruction from the image pickup apparatus, and send, to the image pickup apparatus, a first signal indicating whether the focus lens is able to be moved by a movement amount based on the driving instruction to satisfy the predetermined timing, (a) if the first signal indicates that the focus lens is able to be moved by the movement amount based on the drive instruction to satisfy the predetermined timing, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a first time period, and (b) if the first signal indicates that the focus lens is not able to be moved by the movement amount based on the drive instruction, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a second time period after the first time period, and
• wherein the predetermined timing is timing relating to starting of the charge accumulation for generating the focus signal.

A lens unit detachably mountable to an image pickup apparatus having an image sensor operable to perform charge accumulation and generate an image signal, the lens unit comprising:

• an image taking optical system including a focus lens;
• and
• a lens controller configured to receive a drive instruction for the focus lens from the image pickup apparatus and to control drive of the focus lens on a basis of the drive instruction, said drive instruction is generated on a basis of a focus signal generated by using the image signal,
• wherein a reciprocating operation of the focus lens is performed for determining an in-focus direction before a peak-climbing operation, to drive the focus lens in a direction in which the focus signal is increased, or determining an in-focus state after the peak-climbing operation,
• wherein when the reciprocating operation of the focus lens is performed, the lens controller is configured to receive information relating to a predetermined timing and the drive instruction from the image pickup apparatus, and then send, to the image pickup apparatus, a signal of a predetermined level as a first signal when the focus lens is not able to be moved by a movement amount based on the driving instruction to satisfy the predetermined timing, and
• set a longer stopping time period to stop the focus lens after completion of its movement based on the drive instruction, when sending to the image pickup apparatus the signal of the predetermined level as the first signal, as compared with when sending thereto a signal of a level different from the predetermined level as the first signal, (a) if the lens controller sends a signal of the level different from the predetermined level as the first signal, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a first time period, and (b) if the lens controller sends a signal of the predetermined level as the first signal, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a second time period after the first time period, and
• wherein the predetermined timing is timing relating to starting of the charge accumulation for generating the focus signal.

A method of controlling an image pickup apparatus to which a lens unit provided with an image taking optical system including a focus lens is detachably mountable and which is provided with an image sensor operable to perform charge accumulation and generate an image signal, the method comprising:

• a controlling step of controlling communication with a mounted lens unit;
• a focus signal generating step of generating a focus signal indicating a focus state of the image taking optical system by using the image signal;
• and
• a drive instruction generating step of generating a drive instruction for the focus lens on a basis of the focus signal,
• wherein a reciprocating operation of the focus lens is performed for determining an in-focus direction before a peak-climbing operation, to drive the focus lens in a direction in which the focus signal is increased, or determining an in-focus state after the peak-climbing operation,
• wherein when the reciprocating operation of the focus lens is performed, in the controlling step, the method sends information relating to a predetermined timing and the drive instruction to the lens unit and receives, from the lens unit, a first signal indicating whether the focus lens is able to be moved by a movement amount based on the drive instruction to satisfy the predetermined timing,
• wherein in the drive instruction generating step,
• (a) if the first signal indicates that the focus lens is able to be moved by the movement amount based on the drive instruction to satisfy the predetermined timing, the method generates the new drive instruction by using a focus signal generated based on charge accumulated in a first time period, and
• (b) if the first signal indicates that the focus lens is not able to be moved by the movement amount based on the drive instruction, the method generates the new drive instruction by using a focus signal generated based on charge accumulated in a second time period after the first time period, and
• wherein the predetermined timing is timing relating to starting of the charge accumulation for generating the focus signal.

A method of controlling a lens unit provided with an image taking optical system including a focus lens and detachably mountable to an image pickup apparatus having an image sensor operable to perform charge accumulation and generate an image signal, the method comprising:

• a receiving step of receiving a drive instruction for the focus lens from the image pickup apparatus;
• a sending step of sending information to the image pickup apparatus;
• and
• a controlling step of controlling drive of the focus lens on a basis of the drive instruction, said drive instruction is generated on a basis of a focus signal generated by using the image signal,
• wherein a reciprocating operation of the focus lens is performed for determining an in-focus direction before a peak-climbing operation, to drive the focus lens in a direction in which the focus signal is increased, or determining an in-focus state after the peak-climbing operation,
• wherein when the reciprocating operation of the focus lens is performed, in the receiving step, the method receives information relating to a predetermined timing and the drive instruction from the image pickup apparatus, and a in the sending step, the method sends, to the image pickup apparatus, a first signal indicating whether the focus lens is able to be moved by a movement amount based on the driving instruction to satisfy the predetermined timing, (a) if the first signal indicates that the focus lens is able to be moved by the movement amount based on the drive instruction to satisfy the predetermined timing, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a first time period, and (b) if the first signal indicates that the focus lens is not able to be moved by the movement amount based on the drive instruction, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a second time period after the first time period, and
• wherein the predetermined timing is timing relating to starting of the charge accumulation for generating the focus signal.

A method of controlling a lens unit provided with an image taking optical system including a focus lens and detachably mountable to an image pickup apparatus having an image sensor operable to perform charge accumulation and generate an image signal, the method comprising:

• a receiving step of receiving a drive instruction for the focus lens from the image pickup apparatus;
• a sending step of sending information to the image pickup apparatus;
• and
• a controlling step of controlling drive of the focus lens on a basis of the drive instruction, said drive instruction is generated on a basis of a focus signal generated by using the image signal,
• wherein a reciprocating operation of the focus lens is performed for determining an in-focus direction before a peak-climbing operation, to drive the focus lens in a direction in which the focus signal is increased, or determining an in-focus state after the peak-climbing operation,
• wherein when the reciprocating operation of the focus lens is performed, in the receiving step, the method receives information relating to a predetermined timing and the drive instruction from the image pickup apparatus, and in the sending step, the method sends, to the image pickup apparatus, a signal of a predetermined level as a first signal when the focus lens is not able to be moved by a movement amount based on the driving instruction to satisfy the predetermined timing, and
• wherein, in the controlling step, the method sets a longer stopping time period to stop the focus lens after completion of its movement based on the drive instruction when sending to the image pickup apparatus the signal of the predetermined level as the first signal, as compared with when sending thereto a signal of a level different from the predetermined level as the first signal, (a) if the lens controller sends a signal of the level different from the predetermined level as the first signal, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a first time period, and (b) if the lens controller sends a signal of the predetermined level as the first signal, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a second time period after the first time period, and
• wherein the predetermined timing is timing relating to starting of the charge accumulation for generating the focus signal.

A non-transitory machine readable medium containing program code which upon execution causes an image pickup apparatus to which a lens unit provided with an image taking optical system including a focus lens is detachably mountable and which is provided with an image sensor operable to perform charge accumulation and generate an image signal, to perform:

• a focus signal generating step of generating a focus signal indicating a focus state of the image taking optical system by using the image signal;
• a drive instruction generating step of generating a drive instruction for the focus lens on a basis of the focus signal;
• and
• a controlling step of controlling, when a reciprocating operation of the focus lens is performed, communication with the lens unit comprising sending information relating to a predetermined timing and the drive instruction to the lens unit and receiving, from the lens unit, a first signal indicating whether the focus lens is able to be moved by a movement amount based on the drive instruction to satisfy the predetermined timing,
• wherein in the drive instruction generating step,
• (a) if the first signal indicates that the focus lens is able to be moved by the movement amount based on the drive instruction to satisfy the predetermined timing, the method generates the new drive instruction by using a focus signal generated based on charge accumulated in a first time period, and
• (b) if the first signal indicates that the focus lens is not able to be moved by the movement amount based on the drive instruction, the method generates the new drive instruction by using a focus signal generated based on charge accumulated in a second time period after the first time period,
• wherein the reciprocating operation of the focus lens is performed for determining an in-focus direction before a peak-climbing operation, to drive the focus lens in a direction in which the focus signal is increased, or determining an in-focus state after the peak-climbing operation, and
• wherein the predetermined timing is timing relating to starting of the charge accumulation for generating the focus signal.

A non-transitory machine readable medium containing computer executable program code which upon execution causes a lens unit provided with an image taking optical system including a focus lens and detachably mountable to an image pickup apparatus having an image sensor operable to perform charge accumulation and generate an image signal, to perform:

• a receiving step of receiving, when a reciprocating operation of the focus lens is performed, a predetermined timing and a drive instruction for the focus lens from the image pickup apparatus;
• a controlling step of controlling drive of the focus lens on a basis of the drive instruction;
• and
• a sending step of sending, to the image pickup apparatus, a first signal showing whether or not the focus lens is able to be moved by a movement amount based on the driving instruction to satisfy the predetermined timing, (a) if the first signal indicates that the focus lens is able to be moved by the movement amount based on the drive instruction to satisfy the predetermined timing, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a first time period, and (b) if the first signal indicates that the focus lens is not able to be moved by the movement amount based on the drive instruction, the new drive instruction is generated by using a focus signal generated based on charge accumulated in a second time period after the first time period,
• wherein the reciprocating operation of the focus lens is performed for determining an in-focus direction before a peak-climbing operation, to drive the focus lens in a direction in which the focus signal is increased, or determining an in-focus state after the peak-climbing operation, and
• wherein the predetermined timing is timing relating to starting of the charge accumulation for generating the focus signal.