JPH10161006A - Lens barrel with built-in actuator - Google Patents

Abstract

(57) [Problem] To stabilize a control cycle of an actuator in a lens barrel even when communication with a camera or an accessory is frequently performed. SOLUTION: A microcomputer 4 controls a lens barrel 3 which can communicate by connecting communication lines 6 and 10 to a camera 1 and an accessory 8 and communicates with the outside of the lens barrel.
Is provided. An actuator 7 controlled by the microcomputer and a drive control means 5 for controlling the actuator 7 are provided. A communication means 11 is provided which can perform a first communication state normally performed by the microcomputer and a second communication state for changing the communication time during the actuator control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens mirror with a built-in actuator, which has a built-in actuator such as an ultrasonic motor and a communication means with an accessory such as a camera or a tele-converter (tele-conversion lens). Regarding the tube.

[0002]

2. Description of the Related Art In this type of lens barrel, for example, an A for focusing driving of a focusing lens is used.
A motor in which an F motor is provided inside a lens barrel as an actuator is known. In addition, a microcomputer (hereinafter, referred to as a microcomputer) having a control unit for controlling the motor is mounted in such a lens barrel, and performs various controls, as well as accessories such as a camera and a teleconverter. There is also provided communication means for performing communication between the devices.

As a general software technique, each task process is usually repeatedly executed as a main routine, and when a certain factor occurs, another process different from the normal main routine is performed as an interrupt process. There are algorithms to do. Similarly, in a lens barrel having the above-described AF motor built in as an actuator, control of the actuator and calculations for the control are set in the main routine as one of the task processes, and the communication between the camera and accessories is performed. It adopts a configuration that treats processing whose timing is important as interrupt processing.

In such a lens barrel, in order to quickly transmit information to and from a camera or accessory, it is common practice to shorten a communication interval or increase the number of data exchanged in one communication. I have.

[0005]

In the above described lens barrel with a built-in actuator, there are the following problems in communicating with the camera and accessories together with the internal processing by the microcomputer. In other words, shortening the communication interval or increasing the number of data sent and received in one communication is
The interrupt processing is increased in proportion to the increase, and the time for executing the main routine is reduced. Therefore, the control of the actuator handled in the main routine is affected by the interrupt processing, so that it is not possible to obtain a calculation time for the control, and the control cycle becomes unstable.

[0006] In addition, since the timing is also important for the calculation and control for controlling the actuator, a method of setting the interrupt level of the motor control to be high by performing the interrupt processing may be considered. However, the control of the actuator often requires complicated calculations, and the calculation processing is also long. Therefore, if handled by a high-level interrupt processing, there is a high possibility that other processing will be adversely affected. It should be noted that when performing the interrupt processing with a low level, a result similar to that performed in the main routine is obtained.

Further, there is a method of making the entire communication time longer so that the main routine can be easily executed. However, the communication time becomes longer even when the motor control as the actuator is not being executed, and the efficiency as a whole decreases. Problem.

The present invention has been made in view of such circumstances, and enables a control cycle of an actuator in a lens barrel to be stably performed even when communication with a camera or an accessory is frequently performed. It is an object to obtain a lens barrel with a built-in actuator.

[0009]

In order to meet such a purpose, a lens barrel with a built-in actuator according to the present invention is a lens barrel capable of communicating by connecting a camera and an accessory to a communication line. A microcomputer that controls the inside of the lens barrel and communicates with the outside of the lens barrel, an actuator controlled by the microcomputer, and a drive control unit that controls the actuator by the microcomputer. A first communication state to be performed;
There is provided communication means for performing a second communication state for changing the communication time during actuator control.

Further, the lens barrel with the built-in actuator according to the present invention controls the drive of the actuator by the drive control means by executing the control processing task of the processing for performing the control operation and the control output by the microcomputer at the sampling time. It is configured so that

In such a lens barrel with a built-in actuator according to the present invention, the lens barrel which is necessary for distance measurement and photometry of the camera as the first communication state by the microcomputer to the camera and accessories. Unique data communication, transmission of data that changes as needed with changes in the lens barrel due to focus and various switch states, data or signals such as actuator drive pattern, drive amount, drive speed, camera switch state by camera Is communicated by a certain algorithm.

In the second communication state of the communication means, the control processing task ends when the sampling time at which the control processing task is to be executed is reached during execution of the drive control of the actuator by the drive control means. Only during this period, communication is performed with the communication timing in the first communication state being forcibly delayed.

According to the present invention, even if the microcomputer in the lens barrel is performing frequent communication with the camera or the accessory, only during execution of the control processing of the actuator,
By switching from the normal first communication state to the second communication state having a longer communication time, the time for the control processing task for actuator control can be secured and the control cycle time can be stabilized. In addition, since the switching to the second communication state is performed without setting a long time in the normal first communication state and only when executing the actuator control processing task, the communication is performed at other times. Communication can be performed in the first communication state having a higher speed,
The communication time as a whole can also be suppressed.

[0014]

FIG. 1 shows an embodiment of a lens barrel with a built-in actuator according to the present invention. In this embodiment, an AF motor such as an ultrasonic motor is used as an actuator in a lens barrel, and a teleconverter (teleconversion lens) called a teleconverter attached to increase or decrease the photographing magnification is used as an accessory. The case of using will be described.

In these figures, reference numeral 1 denotes a camera (camera body), and 2 denotes a microcomputer provided in the camera 1. Reference numeral 3 denotes a lens barrel on which a microcomputer (microcomputer) 4 is mounted. 7 is an AF as an actuator
Motor for focusing and driving a focusing lens (not shown) on the optical axis as is widely known. Reference numeral 5 denotes a motor control unit provided in the microcomputer 4.

The microcomputer 4 on the lens barrel 3 side is provided with a communication control unit 11 for communicating with the microcomputer 2 on the camera 1 via a communication line 6. In this communication, the lens barrel 3 transmits information such as information on individual lenses and the current state to the camera 1 side, and transmits information captured by the camera 1 and other information to the lens barrel 3 side. .
The camera 1 transmits the data and the driving amount and speed of the AF motor 7 calculated using the distance measurement result of the subject through the lens barrel 3 to the lens barrel 3 side.

The microcomputer 4 in the lens barrel 3 receiving the result controls the rotation of the AF motor 7 according to the driving amount and speed. The microcomputer 4 also controls the AF motor 7 through the microcomputer 2 in the camera 1 while controlling the drive.
In addition, it keeps sending and receiving the latest data.

In FIG. 1, reference numeral 8 denotes a teleconverter (teleconversion lens; hereinafter referred to as a teleconverter) attached to the camera 1 and the lens barrel 3 as accessories.
Is provided. The microcomputer 9 is configured to exchange various data and control signals with the communication control unit 11 of the microcomputer 4 on the lens barrel 3 via the communication line 10.

The lens drive control state of the microcomputer 4 in the lens barrel 3 will be described below with reference to flowcharts shown in FIGS. First, an outline of the flow of the entire control process in the microcomputer 4 will be described with reference to the flowchart in FIG.

In FIG. 3, step S1 is an initial setting processing step, in which an initial setting state such as an initial value state of each port or register and each interrupt routine is started. Subsequent steps from S2 are a repetition routine (hereinafter referred to as a main routine) as a whole, and each task process is performed in a priority order. Also, when each interrupt occurs during the execution of this main routine,
An interrupt process corresponding to the interrupt factor is performed.

Hereinafter, S2 and subsequent steps will be described in detail. S2
Then, it is determined whether or not to execute the command processing. The factor for command processing occurs when a command is received,
Since it is necessary to immediately determine what the request from the camera 1 is, it is determined whether or not the task processing is to be executed with the highest priority, and if so, the process branches to S3 to be executed.

In the above-described command processing in S3, the contents to be executed are determined in accordance with each command, and preparation for the execution is performed. In executing this command, when executing a motor drive-related command, it is determined whether or not to execute the arithmetic processing in S4. When the command is to be executed, the process proceeds to the arithmetic processing in S5 to perform the arithmetic processing. When this is completed, the process returns to S2. When the arithmetic processing is not performed in S4, the process returns to S2.

If there is no factor for executing the command processing in S2, the process proceeds to S6, and it is determined whether or not to perform the motor control. Here, the factor for executing the motor control is generated by a timer interrupt for each control cycle. When the motor control is performed in this control cycle, the process proceeds to S7 to execute the motor control process. In the motor control process in S7, calculation and control output for controlling the drive amount and drive speed of the AF motor 7 are performed. When this is completed, the process returns to S2.

If it is determined in step S6 that the motor control process is not to be performed, the process proceeds to step S8 to determine whether or not to perform the lens state recognition process. A factor for executing the lens state identification processing in S8 is also generated by a timer interrupt at a constant interval. Then, when executing, the process proceeds to S9. The lens state identification processing in S9 includes an AF lock switch, a range limiter switch, an AF mode switch, and a distance position encoder of the lens barrel 3 (all are not shown).
Is read, and each mode in the lens barrel 3 is switched or data to be transmitted to the camera 1 is switched in the lens state-specific processing in S10.

When this is completed, the process returns to S2. As described above, the entire flow of the main routine is such that each task process is repeated with a priority order, and an interrupt process such as communication enters therein.

Next, a communication method between the camera 1 and the lens barrel 3 (between the camera and the lens) will be described with reference to a time chart of FIG. The communication mode is a clock synchronous serial data communication. In addition, communication line 6
Is composed of a handshake line (hereinafter referred to as R / W line), a clock line for outputting a clock for synchronously transmitting and receiving data, and a data line for transmitting and receiving data.

First, the camera 1 is connected to the R / W of the lens barrel 3.
After confirming that the line is Hi, the R / W line of the camera 1 is lowered to Low. When the R / W line is lowered to Low, the microcomputer 4 in the lens barrel performs the interrupt processing 1 and waits for receiving a command. The camera 1 confirms that the R / W line of the lens barrel 3 has become Low, and sets the R / W line of the camera 1 to Hi. And camera 1
Transmits a command on the data line in synchronization with the clock.

Upon receiving the command, the microcomputer 4 in the lens barrel receives a serial interrupt, performs an interrupt process 2, and executes R / W
Set the line to Hi. Here, the microcomputer 4 in the lens barrel
Runs a timer that interrupts the camera 1 after a short time t so that the R / W line can be confirmed to be Hi. Therefore, when an interrupt is received after time t, the interrupt processing 3
Is performed, and the R / W line is set to Low again.

On the other hand, in response to this, the camera 1 issues a clock again to transmit and receive data to and from the lens barrel 3. As a result, the microcomputer 4 in the lens barrel receives the serial interrupt and performs the interrupt process 2 again. This is performed for the number of data to be transmitted and received, and then the communication is terminated.

Communication is performed as described above, but if communication is performed, interrupt processing increases. Since such an interrupt process is executed by interrupting the main routine, if the number of interrupt routines increases, the time for performing the main routine decreases. Here, the motor control is easily affected by the variation of the control cycle, but the motor control process is a process in the main routine and is directly affected by the communication interrupt. Especially,
When the number of data to be transmitted and received is large, interrupts 2 and 3 occur frequently, which greatly affects the control cycle.

Therefore, according to the present invention, the interruption of serial data transmission / reception is performed by taking measures as shown in the flowchart of FIG. First, when serial data is transmitted / received, the interrupt shown in FIG. 4 is entered. At this point, since other interrupts are prohibited, the interrupt is permitted in S21. S22
To determine whether the received data is a command or data or dummy data for transmission. Therefore, R / W in S23
The line is set to Hi, and a reception process for each reception data is performed in S24.

In the next S25, it is determined whether or not the motor control processing task is being executed. If not, S26 is executed in the normal communication 1 (first communication state), and R / R
The timer time for the timing of setting the W line to Low is set to t.

However, at the timing of executing S25,
If it is between the time when the execution request of the motor control task is generated and the time when the motor control task is completed, the process proceeds to S27,
Replace time t with t + α. Here, α is a value such that the control processing task is sufficiently completed, and t + α is set to a value that does not cause a communication error.

The reason why the time t is set in the former first communication state (communication 1) is that information is transmitted to the camera as soon as possible in communication. In the latter, since the motor control greatly affects the control cycle, + α is provided to ensure that the main routine can be executed. This is set as the second communication state (communication 2), and by performing this, the control cycle can be reliably maintained even in communication with a large number of bytes transmitted and received.

After performing the communication 1 in S26 or the communication 2 in S27, the process proceeds to S28, in which a timer for measuring the time t is started, the interruption processing is exited, and the processing returns to the main routine.

In the above description, the communication of the lens barrel 3 with the camera 1 has been described in detail. However, the communication with the teleconverter 8 as an accessory can be similarly performed. This is shown in FIG. That is, in FIG.
This is clear from the time chart showing the clock and data communication processing between the lens and the telecon. here,
When executing the motor control processing task, the communication at the interval of time t ′ is performed in the normal communication 1 and the time t ′ +
α 'is added.

According to the above configuration, only when the lens barrel 3 executes the motor control processing task, the time α for ensuring that the motor control processing task of the main routine can be executed is reduced by the first normal time. Switching to the second communication state (communication 2) which is added to the first communication state (communication 1) allows the AF motor 7 to be controlled in a stable control cycle even when communication with the camera 1 is performed frequently. . In addition, since the second communication state is switched only when the motor control processing task is executed, communication can be performed in the first communication state in which the communication time is faster than that in other cases,
The communication time as a whole can be suppressed.

The present invention is not limited to the structure described in the above embodiment, and it goes without saying that the shape, structure, etc. of each part can be appropriately modified or changed. For example, the actuator provided in the lens barrel 3 is not limited to the AF motor 7, but may be any actuator that controls the driving of the drive mechanism in the lens barrel 3. The same applies to the teleconverter 8 as an accessory, and any camera accessory that can communicate with the microcomputer 4 and the like in the lens barrel 3 may be used.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first communication state (communication 1) by a communication control unit 11 to a camera 1 and a teleconverter 8 in a microcomputer 4 on a lens barrel 3 side is necessary for distance measurement and photometry of the camera 1. Specific data communication in the lens barrel 3, transmission of data and the like that changes as needed in the lens barrel 3 due to focus and various switch states, a drive pattern, a drive amount, a drive speed of the actuator by the camera 1, and a camera There is a case where any one of data or signal reception such as one switch state is communicated by a certain algorithm.

The second communication state (communication 2) by the communication control unit 11 includes a sampling time during which the control processing task is to be executed while the drive control unit 5 is performing drive control of the actuator (motor 7). The communication may be performed by forcibly delaying the communication timing in the first communication state only from when the control processing task is completed to when the control processing task ends.

[0041]

As described above, according to the lens barrel with built-in actuator according to the present invention, when communication is performed by connecting a camera and an accessory to a communication line, control within the lens barrel and external control of the lens barrel are performed. A microcomputer for communicating with the microcomputer, an actuator controlled by the microcomputer, and drive control means for controlling the actuator by the microcomputer.
And a second communication state in which the communication time is changed during the actuator control is provided. Therefore, despite the simple configuration, the following excellent effects can be obtained.

According to the present invention, even if the microcomputer in the lens barrel is performing frequent communication with the camera or accessory, only during execution of the control processing of the actuator,
By switching from the normal first communication state to the second communication state having a longer communication time, the time for the control processing task for actuator control can be secured and the control cycle time can be stabilized. In addition, since the switching to the second communication state is performed without setting a long time in the normal first communication state and only when executing the actuator control processing task, the communication is performed at other times. Communication can be performed in the first communication state having a higher speed,
The communication time as a whole can also be suppressed.

Therefore, according to the present invention, the control cycle of the actuator in the lens barrel can be stably performed even when communication with the camera or accessory is frequently performed. Here, in the lens barrel with a built-in actuator according to the present invention, the drive processing of the actuator is controlled by the drive control means by executing the control processing task of the processing for performing the control calculation and the control output by the microcomputer at the sampling time. Make up.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a lens barrel with a built-in actuator according to the present invention, and is a block diagram of a camera system including a lens barrel with a built-in AF motor and a teleconverter as an accessory.

FIG. 2 is a time chart for explaining communication waveforms performed between the lens barrel and the camera body and between the lens barrel and the teleconverter in the camera system of FIG. 1;

FIG. 3 is a flowchart showing a main operation in the lens barrel with a built-in actuator shown in FIGS. 1 and 2;

FIG. 4 is a flowchart showing an operation of an interrupt process for the main routine of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Camera, 2 ... Camera side microcomputer (microcomputer), 3 ... Lens barrel, 4 ... Lens barrel side microcomputer (microcomputer), 5 ... Motor control part, 6 ...
Communication line, 7 ... AF motor (actuator), 8
... Telecon as an accessory (teleconverter), 9
... microcomputer (microcomputer) on the telecon side, 1
0: communication line, 11: communication control unit (communication means for controlling first and second communication states).

Claims (4)

[Claims] 1. A lens barrel capable of communicating by connecting a camera and an accessory to a communication line, comprising: a microcomputer for controlling the inside of the lens barrel and communicating with the outside of the lens barrel; and controlling the microcomputer. And a drive control means for controlling the actuator by the microcomputer, a first communication state performed by the microcomputer at a normal time, and a second communication state changing the communication time at the time of the actuator control. A lens barrel with a built-in actuator, characterized by comprising communication means capable of performing the following. 2. The lens barrel with built-in actuator according to claim 1, wherein the microcomputer performs a control processing task of performing a control operation and a control output in a sampling time, thereby driving the actuator by the drive control means. A lens barrel with a built-in actuator, wherein the lens barrel is configured to be controlled. 3. The lens barrel with built-in actuator according to claim 1, wherein the first communication state by the microcomputer to the camera and the accessory is used for distance measurement and photometry of the camera. Unique data communication, transmission of data that changes as needed with changes in the lens barrel due to focus and various switch states, data or signals such as actuator drive pattern, drive amount, drive speed, camera switch state by camera A lens barrel with a built-in actuator, characterized in that any one of the above-mentioned receptions is communicated by a certain algorithm. 4. The lens barrel with a built-in actuator according to claim 1, wherein the communication unit is configured to execute the control processing task from the time when the sampling time to execute the control processing task is reached during the execution of the drive control of the actuator by the drive control unit. A lens barrel with a built-in actuator, wherein communication is performed in a second communication state in which the communication timing in the first communication state is forcibly delayed until the control processing task is completed. .