JPH08129199A - Camera body, camera accessory and camera system - Google Patents

Abstract

PURPOSE: To realize high-speed communication between a camera body and a new lens while the interchangeability of the new and the old lenses is kept. CONSTITUTION: By the microcomputer 1 of a camera body, a low-speed clock is supplied to the lens so as to execute the low-speed communication supported by the old lens at a first serial communication time. When information showing that the high-speed communication can be executed is received from the L microcomputer 3 of the lens at the first serial communication time, a high-speed clock is supplied to the lens so as to execute the high-speed communication supported by the new lens on and after the serial communication time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for communication between a camera body and an accessory mounted on the camera body.

[0002]

2. Description of the Related Art Conventionally, camera accessories such as lenses, etc. (hereinafter, simply referred to as "accessories") mounted on camera bodies exchange data with each other.

For example, data is exchanged between the lens and the camera body in order to transmit information on the lens to the body and information for controlling the lens from the body. There is.

Further, serial communication, which can be realized with a small number of communication connection terminals, is generally used for communication between the lens and the camera body.

[0005]

By the way, the camera body and the accessory cooperate to perform various processes while exchanging data. For example, the camera body and the lens cooperate with each other while exchanging data to perform various types of automatic exposure control and automatic focus control. Therefore, if the time required for data communication is long, the high-speed response of the automatic exposure control and automatic focus control cannot be expected.

On the other hand, in the serial communication performed between such bodies and accessories, the number of transfer data tends to increase as the camera system becomes more intelligent and has more functions. Even under the current situation, if there is a large amount, the amount of data to be exchanged may reach several tens of bytes.

Therefore, it is conceivable to speed up the communication performed between the body and the accessory, but if this is done, there is a problem that the conventional accessory cannot be mounted and used on the camera body.

Here, this problem will be described.

For example, lenses that can be exchangeably mounted on the body come out as a product group with new performance year by year. The same applies to the camera body.

However, it is very convenient for the user to have compatibility between such a camera body and a lens, and a lens interchangeable single lens reflex camera system is supported by many users today. It is also a factor.
In other words, in such an interchangeable lens single-lens reflex camera system, a new camera body can be used by attaching it to the old lens, and a new lens can be attached to the old camera body. It has become available.

An example of this is shown in FIG. As shown in FIG. 29, there can be combinations 1, 2, 3, and 4.

Here, if a communication protocol that realizes high-speed communication is adopted as the communication protocol for the new camera body, the conventional lens cannot support this communication protocol, so that the communication between the two lenses is not possible. It becomes impossible to communicate. Therefore, it becomes impossible to attach the old lens to the new camera body and use it. On the other hand, if a communication protocol that realizes high-speed communication is adopted as the communication protocol for the new lens, it cannot be mounted on the conventional camera body and used.

For this reason, conventionally, even for a new camera body, for example, the communication protocol for supporting the conventional lens has been adopted as the communication protocol. On the contrary, even in the case of a new lens, the communication protocol supported by the conventional camera body has been adopted as the communication protocol.

However, this causes the following problems.

This problem will be described below.

The performance of electronic circuits used in camera bodies and lenses, in particular, microelectronic technology represented by a micro computer (hereinafter abbreviated as "microcomputer") and the like has improved year by year, and these electronic parts have been newly developed. It is possible for the products installed in to have high performance.

Against this background, although the new product group has high performance as described above as compared with the old product group, the communication protocol between the camera and the accessory is as described above. Is performed according to a communication protocol of a relatively low communication speed supported by the conventional product group. That is, the communication between the new lens and the new camera body like the combination 4 in FIG. 29 is also performed by this communication protocol.

Therefore, even though the performance of each of the lens and the camera body is improved, only the communication protocol remains unchanged and the communication speed is not improved. As a result, the improved camera body and lens are improved. The performance cannot be fully exerted.

Such a problem similarly occurs not only in the lens but also between the speedlite and other accessories and the camera body.

Therefore, an object of the present invention is to provide a camera system capable of improving the communication speed between the new camera body and the new accessory while maintaining compatibility with the old product group.

[0021]

[Means for Solving the Problems] To achieve the above object,
The present invention is, for example, a camera body including a control unit that communicates with a camera accessory mounted on the camera body and controls the camera accessory or the camera body, wherein the control unit has a lower communication speed. And a faster communication speed, a communication means for controlling communication with the camera accessory at a set communication speed, out of two types of communication speeds, and when performing the first communication with the camera accessory, As the communication speed used for communication with the camera accessory, the lower communication speed is set in the communication unit, and the subsequent communication allows the camera accessory to communicate at the higher communication speed than the camera accessory. In the case where the information indicating that the communication can be performed is received, the communication speed of the communication means is set to the higher communication speed. To provide a camera body and having a communication speed control means for changing.

Further, the present invention is, for example, a camera body provided with a control unit for communicating with a camera accessory mounted on the camera body to control the camera accessory or the camera body, for the purpose of achieving the above object. The control unit is configured to communicate at two communication speeds, a first communication speed and a second communication speed different from the first communication speed, and the communication unit at the first communication speed. There is provided a camera body, comprising: a communication speed control means for changing a communication speed of the communication means to the second communication speed according to a communication result when communicating with a camera accessory.

[0023]

According to the above-mentioned camera body of the present invention,
The communication speed changing unit of the control unit of the camera body sets the lower communication speed to the communication unit as the communication speed used for communication with the camera accessory when performing the first communication with the camera accessory. Then, when the information indicating that the camera accessory can perform communication at the higher communication speed is received from the camera accessory by the subsequent communication, the setting of the communication speed of the communication unit is performed as described above. Change to a higher communication speed.

Therefore, the attached camera accessory is
If it is a new camera accessory and can communicate at a high communication speed, subsequent communication can be performed at a high communication speed, and the attached camera accessory is an old camera accessory, When communication cannot be performed at a high communication speed, communication with the conventional camera accessory can be enabled by performing communication at a low communication speed as in the conventional case.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a camera system according to the present invention will be described below, taking a case where an accessory is a lens as an example. However, this embodiment can be similarly applied to other accessories such as a speedlite.

First, the first embodiment will be described.

FIG. 1 shows a characteristic part of the camera system according to the first embodiment.

In FIG. 1, a microcomputer 1 in the camera body (hereinafter referred to as "B microcomputer") has a clocked serial communication function, a timer and an RO.
It is a one-chip microcomputer that also incorporates M, RAM and the like. A part of the terminals of the B microcomputer 1 is an R / W1B terminal for handshaking for serial communication with the lens, a CLK terminal for outputting a clock of a clock synchronous type, and a DATA terminal for inputting / outputting data. In the state where the lens is attached, the corresponding R / W1L terminal, I / O terminal, and CLK terminal of the microcomputer 3 on the lens side (hereinafter, referred to as “L microcomputer”) are respectively connected via the connection terminal group 2. It is designed to connect.

In addition, the VCC and the ground terminal, which are the power source, are also connected to the lens and the camera body side by using the same connection terminal, and the electric power is supplied from the camera body side to the lens side.

Further, the DC-DC converter 5 in the camera body which receives the battery power source 4 and outputs a constant voltage.
The constant voltage is supplied to the power supply lines of the B and L microcomputers 1 and 3.

In the camera body thus constructed, the B-microcomputer 1 executes a predetermined camera control program stored in the ROM after power is applied and reset.

FIG. 2 shows an outline of processing executed by the B-microcomputer 1 according to this control program.

As shown in the figure, the B-microcomputer 1 initializes at step (# 31), then activates lens communication at step (# 32), AF control at step (# 33), and AE at step (# 34). The control process is repeatedly executed.

In addition, the B-microcomputer 1 executes the release routine shown in FIG. 3 as an interrupt process activated by an interrupt due to a change in the state of the release SW terminal connected to the B-microcomputer 1. In this routine,
After controlling the aperture of the lens in (# 41),
2) The shutter of the camera body is controlled to expose the fill. Then, (# 43) shutter charge control processing, film feeding control processing, etc. are activated to prepare for the next release routine.

Next, the details of the (# 32) lens communication starting process in FIG. 2 will be described.

In FIG. 4, when the lens sends a predetermined number of bytes of data to the camera body in response to a command sent from the camera body, I of both the camera body and the lens
The waveforms of the input / output signals of the / O terminal and the CLK terminal are shown. Also, the waveform of the output signal from the camera body side to the R / W1B terminal and the waveform of the output signal from the lens side to the R / W1L terminal are shown.

However, R / W1B and R / W1L are
They are connected by a common line R / W1, and the R / W1 line is "L" unless both the camera body and the lens output "H".

That is, as shown in FIG. 5, an input / output driver for the R / W1 terminal of the camera body and an R on the lens side.
The input / output driver to / W1L has an open drain structure. When both the camera body and the lens of the R / W1 line output “H” to R / W1B and R / W1L, It becomes “H” by the pull-up resistor 400.

As shown in the figure, eight clock pulses are output from the camera body side to the CLK terminal for each 1-byte communication. Data is transmitted and received between the camera body and the I / O terminals of the lens in synchronization with the clock of the CLK terminal.

The data transfer direction between the I / O terminals is bidirectional, and the camera body transmits at the time of the first command transmission, the lens receives, and the data from the data 1 to the data N after that the lens moves. It is assumed that a communication protocol such as transmission and reception by the camera body is previously promised between the lens and the camera body.

In the lens communication activation process of step (# 32) of FIG. 2 performed by the B microcomputer of the camera body, as shown in FIG. 6, first, in step (# 61), the R / W1 is set.
The B terminal is set to "L". This corresponds to that in FIG. In response to this, the L microcomputer 3 on the lens side sets R / W1L to "L".

Next, the B microcomputer 1 executes the step (# 6
The timer of 1.6 mS is started in 2) and the process returns to the flow of FIG. With this 1.6mS timer, 1.6m
After the lapse of S, a timer interrupt is generated, and the B microcomputer 1 executes the 1.6 mS timer interrupt processing routine of FIG. 7 by the interrupt.

In this 1.6 mS timer interrupt routine, as shown in FIG. 7, first, in step (# 71), R /
Set the W1B terminal to "H". (Actually, the "L" output of the open drain terminal output is turned off.) Then, it is determined whether the R / W1 terminal is "L" (step # 72).
Identify with. It corresponds to that of FIG.

In step (# 72), if the result of the level check of the R / W1 terminal is "H", it is determined that there is no lens response, and in step (# 73) the lens is not attached and lens communication ends. If the result of the level check is "L", it is determined that the lens side has responded and the process proceeds to the next step.

At step (# 74), it is checked whether the high speed communication enable flag is "1". This high-speed communicable flag is set / reset in the flow described later, but is initially set to "0" by the initialization in step (# 31) of FIG.

Therefore, at least in the first communication, the determination in step (# 74) is No, and thus in step (# 7).
Go to 5) and set the serial clock frequency to 125K
Hz is set.

Next, in step (# 77), the command data to be sent to the lens is set in a predetermined serial transmission buffer, the serial communication completion interrupt is enabled in step (# 78), and the serial communication is completed in step (# 79). Trigger a send.

Here, when the serial transmission is activated, the serial communication hardware of the B-microcomputer 1 outputs the clock of the serial clock frequency set in step (# 75) or step (# 76) to the CLK terminal. At the same time, in synchronization with this, the transmission command data is output to the I / O terminal. When this transmission is completed, a serial transmission completion interrupt is generated. This data transmission is shown in Figure 4.
Corresponds to.

On the other hand, the L microcomputer 3 on the lens side has already made serial data reception possible when R / W1L is set to "L" as a response, and the I / O is synchronized with the clock input to its own CLK terminal. Receives command data input to the terminal.

When the serial transmission is completed, the serial transmission completion interrupt is activated and the B-microcomputer 1 shifts to the serial interrupt routine of FIG.

That is, in step (# 81), the edge interrupt is enabled to recognize the falling edge of R / W1 as the ready for the received data, and the process returns.

When the L-side microcomputer 3 on the lens side receives the command serially, it once sets R / W1 to "H" (Fig. 4), and when it is ready to send the lens data to the camera, the R / W1 is again set to "H". L ″ (in FIG. 4). And
After that, when a clock is input from the camera body to the CLK terminal of the lens, data is output to the I / O terminal of the lens in synchronization with this.

On the other hand, by the permission in step (# 81), an edge interrupt is generated in the B microcomputer 1 by the change of R / W1 from "H" to "L". When the edge interrupt occurs, the B-microcomputer 1 starts the edge interrupt routine shown in FIG.

In this edge interrupt routine, the serial reception completion interrupt is enabled in step (# 91), the edge interrupt is prohibited in step (# 92), and the serial reception process is activated in step (# 93). To return.

When the serial reception process is activated here, B
The serial communication hardware of the microcomputer 1 outputs a clock of the set serial clock frequency, and the reception data sent from the lens to the I / O terminal in synchronization with this is stored in a predetermined reception buffer.

First, since the serial reception completion interrupt is permitted in step (# 91), when the serial reception operation is completed, the serial reception completion interrupt is generated in the B microcomputer 1.

When a serial reception completion interrupt occurs,
The control flow of the B-microcomputer 1 shifts to the serial reception completion interrupt routine shown in FIG.

In the serial reception completion interrupt routine,
In step (# 101), the data is fetched from the reception buffer, in step (# 102), stored in the internal RAM, and in step (# 103), it is determined whether the received data is the last data (Nth data). do. If the received data still exists, the edge interrupt is permitted again in step (# 104) to prepare for the data transmission ready of the L-microcomputer 3.

When the received data is the last received data, the process proceeds to step (# 105) to end the serial communication, the high speed communication determination process is performed in step (# 106), and then the process returns.

On the other hand, when the L-side microcomputer 3 on the lens side transmits 1-byte data, it once sets R / W1L to "H" and then prepares to transmit the next data to the camera.
Set W1L to "L" again, then from the camera body,
When a clock is input to the CLK terminal of the lens, the process of outputting data to the I / O terminal of the lens in synchronization with this is repeated until the transmission of the last data (Nth data) is completed.

On the other hand, in the B-microcomputer 1, the high-speed communication determination processing performed when the received data is the last is as shown in FIG.
1 is performed.

That is, when bit 0 of the data 2 received in step (# 111) is "1", it is determined that high speed communication is possible, and the high speed communication possible flag is set to "1" in step (# 112). When bit 0 of data 2 is "0", it is determined that high speed communication is impossible and the high speed communication flag is set to "0" in step (# 113).

When the high-speed communication enable flag is set to "1", the 1.6 ms timer interrupt routine (FIG. 7), which is performed at the next lens communication activation processing of FIG. 2 (# 31).
When the determination is YES in step (# 74), the serial clock frequency is 500K in step (# 75).
Hz is set, and subsequent communication will be performed at 500 KHz.

Here, the L microcomputer 3 of the conventional lens is
It is assumed that “0” is transmitted as bit 0 of data 2 and serial communication cannot be executed unless the clock rate is 125 KHz or less.

On the other hand, the L microcomputer of the new lens has improved circuit performance on the lens side, can serially communicate at a clock rate of 500 KHz or less, and is configured to transmit bit 0 of data 2 as "1". .

Therefore, after the first communication in the combination of the new lens and the new camera body, 500 KH
Serial communication in z can be performed. FIG. 12 shows communication waveforms in the subsequent communication that is switched to the high speed communication in this way. Compared with FIG. 4, the communication speed is 2
You can see that it has doubled.

By the way, in the above description, the B microcomputer 1 of the camera body uses the bit information (data 2) of the received data.
Bit 0) of whether the high-speed communication is performed or not is switched from the lens to the L microcomputer 3 during the first communication.
CPU version data may be transmitted, and switching may be performed in accordance with this.

For example, the high-speed communication determination processing shown in FIG. 11 is modified as shown in FIG. 13, and when the version sent from the lens is larger than 05H, step (# 1
In step 23), the high speed communication enable flag is set.
In this case, a new lens L microcomputer 3 capable of high-speed communication
Gives a value of 06H or more as the CPU version data.

Alternatively, the lens may transmit a unique identification number indicating the lens type itself at the time of the first communication, and the high speed communication may be switched according to this.

For example, the high speed communication determination process shown in FIG. 11 is modified as shown in FIG. 14, and when the unique identification number sent from the lens is larger than 32H, the high speed communication enable flag is set in step (# 132). To do so. In this case, a lens capable of high-speed communication is given a unique identification number of 33H or more.
The second embodiment of the present invention will be described below.

The second embodiment relates to a case where asynchronous asynchronous serial communication is performed between the camera body and the lens.

FIG. 15 shows a characteristic part of the camera system according to the second embodiment.

The same parts as those of the camera system according to the first embodiment are designated by the same reference numerals. The second book shown in FIG.
The configuration of the camera system of the embodiment differs from the configuration of the camera system of the first embodiment in that there is no clock line for synchronization (and CLK terminal). Further, in the second embodiment, the DATA of the B microcomputer 1 and the L microcomputer 3 are
Performs half-duplex communication between terminals.

FIG. 16 shows communication waveforms between the camera body and the lens in the second embodiment.

The operation of the camera system according to the second embodiment is the same as that of the first embodiment except that the asynchronous communication is performed.

However, instead of the 1.6 ms timer interrupt processing of FIG. 7 performed in the first embodiment, the 1.6 ms timer interrupt processing of FIG.
The ms timer interrupt process is performed.

In the 1.6 ms timer interrupt process of FIG. 17, if the high speed communication is possible in the step (# 174) (when the high speed communication flag is set), the step (#
In 176), the rate 38400 bps is selected. When high-speed communication is not possible, the rate is 9600 bps
Select.

Further, since the camera body unilaterally outputs the clock in the first embodiment, there is no particular need to recognize that the clock speed has been switched on the lens side. Then, it is necessary for the new lens side to recognize that the transfer rate has been switched. Therefore, in the second embodiment, this is the first 960
In the command transmitted from the camera body to the lens by 0 bps communication, the data indicating that the new high speed communication is possible is included in the command, and the L microcomputer 3 of the lens, based on this data, transmits its own data. Switch the send / receive speed. As described above, in the second embodiment, the first communication is always executed at 9600 bps, and the second and subsequent communication is executed at the communication speed according to the communication result. To do. Thus, in the combination of the new lens and the new camera body, the 38400 bps rate is applied in the second and subsequent communications. Therefore, the new camera body and new lens have been changed to a high-speed porate, and in the combination using the old lens and the old camera body, the conventional 9600 bps porate is applied as it is even in the second and subsequent communication, and communication is smoothly performed. I can continue.

The third embodiment of the present invention will be described below.

In the third embodiment, in the camera system having the same structure as that of the first embodiment (see FIG. 1), not the transfer rate of the communication data but the response time of the communication handshake can be communicated at high speed on the lens side of the camera body. This is a case where it is identified and whether or not to switch.

That is, from the time when the lens side receives or transmits 1-byte data in FIG. 18 and R / W1L is once changed from "L" to "H",
The time until R / W1L is changed from "H" to "L" to indicate the completion of preparation for the next data transmission is switched by a command sent from the camera body.

As shown in FIG. 4, the processing capability of the conventional camera body is low, and in order to recognize the transition of R / W1L, a time of at least 100 uS was required between the two and the figure. However, as shown in FIG. 18, in the new camera body, the performance is improved so that the time can be recognized even at 10 uS, so when the lens recognizes that it is a new camera body capable of high-speed communication, It is a time switch.

FIG. 19 shows a process performed by the lens side microcomputer (L microcomputer 3) in order to realize such switching.

In this process, first, step (# 190
In 0), the L microcomputer 3 repeatedly determines whether the R / W1 terminal is "L" and prepares for communication start from the camera body side.

When "R" of the R / W1 terminal is recognized in step (# 1900), R / W1L is set to "L" in order to recognize that the camera body has responded in step (# 1901).

At step (# 1902), completion of command data reception from the camera body is waited, and when received, it is determined at step (# 1903) whether the command is larger than "26H", for example. When it is larger than "26H", the high speed communication enable flag is set to "1" in step (# 1905). If it is "26H" or less, the high speed communication enable flag is set to "0" in step (# 1904). However, the command used by the old camera body is "26H" or less, and the new camera body capable of high-speed communication is "27H" or more.

Next, in step (# 1906), R / W1L
After setting to "H", it is checked in step (# 1907) whether the last data is transmitted.

When the last data is transmitted, the process returns to the first communication start waiting in step (# 1900). When the last data is not transmitted, step (# 1908)
The transmission data is set in the transmission buffer with step, and the high speed communicable flag is checked in step (# 1909).

If the high-speed communication enable flag is "1", 10 is passed after the R / W1L is set to "H" in step (# 1911).
If uS has elapsed, determine whether it has elapsed, and if it has elapsed, proceed to step (# 1
912). If the high-speed communication enable flag is "0", it is determined whether 100uS has elapsed since R / W1L was set to "H" in step (# 1910), and if it has elapsed, go to step (# 1912) to set R / W1L to "L". "Yes.

Next, in step (# 1913), the completion of serial transmission is waited, and when it is completed, R / W1L1 is set to "H" again in step (# 1096) and repeated until the last data is transmitted.

The embodiments of the camera system according to the present invention have been described above.

In each of the above embodiments, the same effect can be obtained even if the roles of the B microcomputer 1 of the camera body and the L microcomputer 3 of the lens are exchanged.

In the above embodiment, the low speed communication is first performed from the camera body side to determine whether the high speed communication is possible, and the communication speed is switched. However, this may be done as follows. That is, first, high-speed communication may be performed from the camera body side, it may be determined whether high-speed communication is impossible, and the communication speed may be switched. In this case, whether or not high-speed communication is impossible can be determined by, for example, whether or not the response data expected from the camera body side to the high-speed communication can be received from the lens side.

In the following, a case will be described as a fourth embodiment in which high speed communication is first performed from the camera body side, it is determined whether high speed communication is impossible, and the communication speed is switched.

The configuration of the camera system according to the fourth embodiment is the same as that of the camera system according to the first embodiment (see FIG. 1) described above. However, in the fourth embodiment, the camera body first performs high-speed communication, and determines whether or not the lens can perform high-speed communication based on whether or not high-speed communication is established.

Hereinafter, in the fourth embodiment, the B microcomputer 1 will be described.
The process performed by the L microcomputer 3 and the process performed by the L microcomputer 3 will be described. First, the processing performed by the B microcomputer 1 will be described.

FIG. 20 shows an outline of the processing performed by the B-microcomputer 1 in the camera body.

As shown, when the power is turned on, B
The microcomputer 1 clears the RAM provided in step (# 301) and initializes the serial communication function. In the fourth embodiment, the high speed communicable flag is set to 1 in step (# 301). Then, next, step (# 302)
After executing the lens communication start-up processing in step (# 30
AF control is performed in 3), AE control is executed in step (# 304), and when the process is completed, the processing from step (# 302) is repeated.

FIG. 21 shows the step (# 302) in FIG.
22 shows the details of the lens communication start processing, and FIG. 22 shows the waveforms of input / output signals between the camera body and the lens. However, as described above, R / W1L and R / W1B represent the output waveforms of the lens and the camera body, respectively, and R / W1 connecting R / W1L and R / W1B is actually the lens It is "L" unless both camera bodies output "H" (actually, "L" output to both open drain terminals R / W1L and R / W1B is off).

In the lens communication starting process shown in FIG. 21, first, in step (# 311), R / W1B is set to "L" as a call to start communication with the lens (FIG. 22).
of). And 1.6m for "L" holding time of R / W1B
After starting the S timer in step (# 312), the process returns to step (# 303) in FIG. 20 in step (# 313).

Here, the 1.6 mS timer generates a timer interrupt request when the timer time has elapsed after starting. When the timer interrupt request is generated, the B-microcomputer 1 executes the "1.6 mS timer interrupt process" shown in FIG. 23 as the interrupt process.

As shown in the figure, in the 1.6 mS timer interrupt process, first in step (# 3201), the R / W1B
To "H". This step corresponds to that in FIG.
Then, after this, it is identified in step (# 3202) whether R / W1 is "L".

As described above, this R / W1 becomes "H" due to the pull-up resistor if either the camera body or the lens is "L". In this case, the step (# 32
Since R / W1B is set to "H" in 01), the lens is R
If / W1L is not set to "L", it becomes "H" due to the pull-up resistor.

Next, in step (# 3202), R / W1
If the result of the check is "H", it is determined that there is no lens response, the lens is not attached in step (# 3203), and the lens communication is completed, and 1.6 m is set in step (# 3204).
The process returns to the step before the start of the S timer interrupt process.

On the other hand, if the result of the R / W1 check is "L", it is assumed that the lens side has responded and the next step (# 32).
Go to 05). In step (# 3205), it is checked whether the high speed communication enable flag is "1". This high-speed communicable flag is set / reset by the "3 ms timeout interrupt processing" described later, but initially it is initialized to "1" in step (# 301) of FIG. Therefore, at least for the first communication, the step (# 320
The determination in 5) is Yes, the process proceeds to step (# 3206), and 500 KHz is set as the serial clock frequency. On the other hand, when the high-speed communication enable flag is "0", 125 KHz is set as the serial clock frequency in step (# 3207).

Next, in step (# 3208), command data to be sent to the lens is set in the serial transmission buffer, the serial transmission completion interrupt is enabled in step (# 3209), and serial transmission is activated in step (# 3310). Then, in step (# 3311), the process returns to the step before starting the 1.6 mS timer interrupt process.

Here, when the serial transmission is activated, the serial communication hardware of the B-microcomputer 1 CLKs the clock of the serial clock frequency set in step (# 3206) or step (# 3207).
The data is output to the terminal and the transmission data is output to the I / O terminal in synchronization with this. When this transmission is completed, a serial transmission completion interrupt is generated. This command transmission corresponds to that in FIG.

The L-side microcomputer 3 on the lens side is already ready for serial reception when R / W1 is set to "L" as a response.

After that, when the serial transmission is completed and a serial transmission completion interrupt request is generated, the B-microcomputer 1 executes the "serial transmission completion interrupt process" shown in FIG. 24 as the interrupt process.

In this process, as shown in the figure, in step (# 331), it is determined whether or not the L microcomputer 3 has changed R / W1L from "H" to "L" in order to notify the completion of preparation for the next data transmission. From “H” of R / W1 to detect
Enable "edge interrupt" to "L", and step (# 33
In 2), a 3 mS timer is activated for timeout, and in step (# 333), the process returns to the step before the start of the serial transmission completion interrupt process.

Now, since the command and the like are transmitted from the camera body to the lens at a high speed of 500 KHz, the L microcomputer 3 of the conventional lens, which cannot perform high speed communication of 500 KHz, transmits this command. The reception completion cannot be recognized because it cannot be received. Therefore, the reception completion is recognized and the R / W1
After setting L to "H", change R / W1L from "H" to "L" to indicate the completion of preparations for sending data to the camera body in response to commands sent from the camera body. I can't. And at this point, R / W1B
Maintains R / W1B at "H", in this case, no edge from "H" to "L" occurs at R / W1. Therefore, in this case, in step (# 332), the 3 mS timer times out for time-out, and a 3 mS timer time-out interrupt request is generated. The details of the processing performed by the L-microcomputer 3 for such a lens will be described later.

On the other hand, when the lens is capable of high speed communication of 500 KHz, R / W1 is set to "H".
To "L", an edge interrupt request is generated. Note that the time of 3 mS is set to R / W1L to indicate that the camera body is ready for data transmission when serial reception of the lens is normally completed.
It takes a sufficiently long time to change from "H" to "L" compared to the time from the end of serial transmission from the camera body.

When the 3mS timeout interrupt request is generated because the lens cannot perform high-speed communication, the microcomputer B executes "3mS timeout interrupt process" shown in FIG. 25 as the interrupt process.

As shown in the figure, in this processing, the B-microcomputer 1 sets the high-speed enable communication flag to 0 in step (# 341).
Before, the 3 mS timer is stopped in step (# 342), all the processes related to communication with the lens are ended in step (# 343), and the 3 mS timeout interrupt process is started in step (# 344). Return to step processing.

When communication is resumed after the execution of step (# 341), step (# 3205)
Step (# 3207) is executed according to the judgment result of 1
A serial clock frequency of 25 KHz will be set.

On the other hand, when an edge interrupt request (corresponding to that in FIG. 38) that occurs when the lens can perform high-speed communication as described above, the B-microcomputer 1 interrupts the "edge interrupt processing" shown in FIG. Execute as a process.

As shown in the figure, in this process, the timeout 3 mS timer is stopped in step (# 351), and the serial reception completion interrupt is enabled in preparation for receiving data from the lens in step (# 352). Then, the edge interrupt is prohibited in step (# 353), the serial reception is activated in step (# 354), and the step (#
In step 355), the process returns to the step before the start of the edge interrupt process.

When serial reception is activated, the serial communication hardware of the B-microcomputer 1 outputs a clock of the set serial clock frequency to the CLK terminal and, in synchronization with this, outputs it to the I / O terminal. The reception data sent from the lens is stored in the reception buffer.

When the serial reception of the received data is completed, the serial reception completion interrupt is enabled, so that the serial reception completion interrupt is generated.

When a serial reception completion interrupt occurs,
The B-microcomputer 1 executes the "serial reception completion interrupt process" shown in FIG. 27 as an interrupt process.

In this process, as shown in the figure, the data received from the lens is acquired from the reception buffer in step (# 361), and the internal RAM is acquired in step (# 362).
Then, in step (# 363), it is determined whether the received data is the last received data (Nth data), and if it is the last received data, the serial communication is ended in step (# 364). In # 367), the process returns to the step before the start of the serial reception completion interrupt process.

If it is determined in step (# 363) that the received data is not the final received data, step (# 365)
Then, the timer of 3 mS for the time-out is started again, and then the edge interrupt is permitted to detect the edge change of R / W1 indicating the completion of the next transmission preparation on the lens side in step (# 366), and (# 367). Returns to the process of the step before starting the serial reception completion interrupt process.

The processing performed by the B-microcomputer 1 on the camera body in the fourth embodiment has been described above.

Next, the processing performed by the L microcomputer 3 of the lens in the fourth embodiment will be described. In FIG. 28, L
The procedure of processing performed by the microcomputer 3 will be described.

As shown in the figure, the L-microcomputer 3 first monitors that R / W1 is "L" in step (# 3700), and if "L" is recognized, R / W1 is detected in step (# 3701).
Set W1L to "L" and start timing. Then, in step (# 3702), it is determined whether or not 1-byte serial reception is completed based on the clock sent from the body through the CLK terminal. Then, while it is not completed, it is determined in step (# 3703) whether or not the measured time has passed 5 mS, and when it is not elapsed, the process returns to step (# 3702) again. That is, it is detected whether the operation of receiving 1-byte data from the camera body is completed within 5 mS.

Here, when the lens is a conventional lens that cannot perform high speed communication and cannot respond to the clock of 500 KHz sent from the camera body, the serial reception cannot be recognized in the L microcomputer 3,
The reception completion cannot be recognized, and as a result, 5 mS elapses.

Therefore, by the judgment of step (# 3703), the process proceeds to step (# 3704), where R / W1L is set to "H" (corresponding to FIG. 22), and then step (# In 3705), the processing related to communication is initialized and the process returns to the first step (# 3700).

On the other hand, when the L-microcomputer 3 is a new lens, the completion of serial reception can be normally recognized in response to the clock of 500 KHz sent from the camera body. Therefore, the determination in step (# 3702) leads to step (# 37).
The process proceeds to 06). Even if the camera body and the lens are both old ones that cannot perform high-speed communication, the completion of serial reception can be normally recognized in response to the clock of 125 KHz sent from the camera body.
Depending on the judgment of step (# 3702), step (#
Then, the process proceeds to 3706).

Now, in the step (# 3706), R /
W1L is set to "H", and it is determined in step (# 3707) whether the last data (Nth data) has been transmitted. If it is the last data, the process proceeds to step (# 3705).
If it is not the last data, further step (# 370
In step 8), the transmission data is set in the transmission buffer, and in step (# 3709), R / W1L is set to "L" to start timing. Then, it is checked whether the serial transmission from the lens to the camera body, which is performed by sending the clock from the camera body side, is completed (# 371).
0) and step (# 3711) monitor for a maximum of 5 ms. When the serial transmission is completed within a time of 5 mS or less, the process returns from step (# 3706).

On the other hand, if serial transmission is not possible even after 5 mS has passed, R / W1L is determined in step (# 3704).
Is set to "H", communication-related processing is initialized in step (# 3705), and the process returns to step (# 3700).

The fourth embodiment of the present invention has been described above.

As described above, according to the fourth embodiment of the present invention, high speed communication is first executed, and high speed communication is continued as it is or switched to a lower speed communication according to the result. Decide Therefore, high-speed communication is maintained for the case of a new type of lens, and low-speed communication is switched for the case of a conventional lens, and thereafter communication is performed under the control of low-speed communication.

The roles of the B microcomputer 1 of the camera body and the L microcomputer 3 of the lens in the fourth embodiment may be exchanged.

[0134]

As described above, according to the present invention, the communication speed can be increased with the new lens and the new camera body while maintaining compatibility with the old and new cameras and lenses, thereby improving the performance of the camera system. Can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a characteristic part of a camera system according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 4 is a timing chart showing communication timing between the camera body and the lens according to the first embodiment of the present invention.

FIG. 5 is an R diagram of the camera system according to the first embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of an input / output unit of a / W signal.

FIG. 6 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 8 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 9 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 10 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 11 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 12 is a timing chart showing communication timing between the camera body and the lens according to the first embodiment of the present invention.

FIG. 13 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 14 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a characteristic part of the camera system according to the first example of the present invention.

FIG. 16 is a timing chart showing communication timing between the camera body and the lens according to the second embodiment of the present invention.

FIG. 17 is a flowchart showing the processing performed by the microcomputer of the camera body according to the second embodiment of the present invention.

FIG. 18 is a timing chart showing communication timing between the camera body and the lens according to the third embodiment of the present invention.

FIG. 19 is a flowchart showing the processing performed by the microcomputer of the camera body according to the third embodiment of the present invention.

FIG. 20 is a flowchart showing the processing performed by the microcomputer of the camera body according to the first embodiment of the present invention.

FIG. 21 is a flowchart showing the processing performed by the microcomputer of the camera body according to the fourth embodiment of the present invention.

FIG. 22 is a timing chart showing communication timing between the camera body and the lens according to the fourth embodiment of the present invention.

FIG. 23 is a flowchart showing the processing performed by the microcomputer of the camera body according to the fourth embodiment of the present invention.

FIG. 24 is a flowchart showing the processing performed by the microcomputer of the camera body according to the fourth embodiment of the present invention.

FIG. 25 is a flowchart showing the processing performed by the microcomputer of the camera body according to the fourth embodiment of the present invention.

FIG. 26 is a flowchart showing the processing performed by the microcomputer of the camera body according to the fourth embodiment of the present invention.

FIG. 27 is a flowchart showing the processing performed by the microcomputer of the camera body according to the fourth embodiment of the present invention.

FIG. 28 is a flowchart showing a process performed by the microcomputer of the lens according to Example 4 of the present invention.

FIG. 29 is a diagram showing a combination of an old lens and a new camera body.

[Explanation of symbols]

1 Microcomputer in camera body (B microcomputer) 3 Microcomputer on lens side (L microcomputer)

Claims (9)

[Claims] 1. A camera body including a control unit that communicates with a camera accessory mounted on the camera body and controls the camera accessory or the camera body, wherein the control unit has a lower communication speed. , A communication unit that controls communication with the camera accessory at a set communication speed of two types of communication speeds of higher speed and a communication speed for the first time with the camera accessory, As the communication speed used for communication with the camera accessory, the lower communication speed is set in the communication unit, and the subsequent communication allows the camera accessory to communicate at the higher communication speed than the camera accessory. When the information indicating that the communication can be performed is received, the communication speed setting of the communication means is changed to the higher communication speed. The camera body and having a communication speed control means for. 2. A camera body including a control unit that communicates with a camera accessory mounted on the camera body and controls the camera accessory or the camera body, wherein the control unit has a lower communication speed. , A communication unit that communicates with the camera accessory at a communication speed that is set, out of two types of communication speeds including a higher communication speed, and communication between the camera accessory and the camera accessory. When the accessory receives information indicating that communication can be performed at the higher communication speed, the communication speed of the communication means is set to the higher communication speed, and the higher communication speed is set. When the information indicating that the communication can be performed at the speed is not received, the communication speed of the communication unit is set to the lower speed than the above. The camera body and having a communication speed control means for setting the baud rate. 3. A camera body including a control unit that communicates with a camera accessory mounted on the camera body and controls the camera accessory or the camera body, wherein the control unit has a lower communication speed. , A communication unit that controls communication with the camera accessory at a set communication speed of two types of communication speeds of higher speed and a communication speed for the first time with the camera accessory, As the communication speed used for communication with the camera accessory, the higher communication speed is set in the communication means, and the expected response to the communication performed at the higher communication speed thereafter is And communication speed control means for changing the communication speed setting of the communication means to the slower communication speed when the communication speed cannot be received from the camera accessory. Camera body, characterized in that. 4. A camera body including a control unit that communicates with a camera accessory mounted on the camera body and controls the camera accessory or the camera body, wherein the control unit has a first communication speed and A communication means capable of communicating at two communication speeds, a second communication speed different from the first communication speed, and a communication result when communication is performed with the camera accessory at the first communication speed. And a communication speed control means for changing the communication speed of the communication means to the second communication speed. 5. A camera accessory including a control unit that communicates with a mounted camera body, wherein the control unit has two communication speeds, a lower communication speed and a higher communication speed. A communication means for communicating with the camera body at a set communication speed, and in the communication with the camera body, the camera body communicates at a higher communication speed than the camera body. When the information indicating that the communication can be performed is received, the communication speed of the communication unit is set to the higher communication speed, and the information indicating that the communication can be performed at the higher communication speed is received. And a communication speed control means for setting the communication speed of the communication means to the lower communication speed. 6. A camera accessory including a control unit that communicates with a mounted camera body, wherein the control unit has two communication speeds, a lower communication speed and a higher communication speed. Of the above, the communication means for controlling communication with the camera body at the set communication speed, and the communication speed used for communication with the camera body when performing the first communication with the camera body, When a high-speed communication speed is set in the communication means and the expected response to the communication thereafter performed at the higher communication speed cannot be received from the camera body, the communication of the communication means A camera accessory, comprising: a communication speed control means for changing a speed setting to a communication speed lower than the above. 7. A camera system comprising a camera body and a camera accessory mounted on the camera body, which communicate with each other, wherein the camera accessory communicates with the camera body at a communication speed controlled by the camera body. And a camera accessory control unit that transmits information indicating whether or not subsequent communication can be performed at a higher communication speed in communication with the camera body to the camera body, The camera body includes a camera body control unit that communicates with the camera accessory and controls the camera accessory or the camera body, and the camera body control unit includes a lower communication speed and a higher communication speed. Of the two communication speeds including the two communication speeds Communication means for controlling the communication of, and when performing the first communication with the camera accessory, as the communication speed used for communication with the camera accessory, the slower communication speed is set in the communication means, and thereafter, When the information indicating that the camera accessory can perform communication at the higher communication speed is received from the camera accessory by the communication, the communication speed of the communication unit is set to the higher speed. A camera system comprising: a communication speed control unit for changing the communication speed. 8. A camera system comprising a camera body for communicating with each other and a camera accessory mounted on the camera body, wherein the camera body communicates with the camera accessory, A camera body control unit that controls the camera body is provided, and the camera body control unit, in communication with the camera accessory, information indicating whether or not subsequent communication can be performed at a higher communication speed. To the camera accessory, the camera accessory includes a camera accessory control unit that communicates with the attached camera body, the camera accessory control unit, a slower communication speed and a higher communication speed Communication that communicates with the camera body at a set communication speed of two types of communication speed In the communication with the camera body, when the information indicating that the camera body can perform communication at the higher communication speed is received from the camera body, the communication speed of the communication unit When the setting is set to the higher communication speed and the information indicating that the communication can be performed at the higher communication speed is not received, the communication speed of the communication means is set to the lower communication speed. And a communication speed control means for setting a different communication speed. 9. The camera system according to claim 7, wherein the camera accessory is a lens.