JPH08101433A - Camera - Google Patents

Abstract

PURPOSE: To reduce the cost of a product and to assure the stable operation of a camera by automatically selecting operation signals varying in oscillation frequency in accordance with the time accuracy, etc., of the respective operations of the camera and making these signals functionally corresponding to the respective operations of the camera. CONSTITUTION: This camera has CR oscillation circuits 1, 2 having low frequency stabilization accuracy and high oscillation frequency, a crystal oscillation circuit 3 having high frequency stabilization accuracy and low oscillation frequency, a selection circuit 7 for selecting one of the signals of the respective oscillation circuits, an oscillation information storage circuit 8 for storing the frequency stabilization accuracy of the respective oscillation circuits, a central control circuit 10 for controlling the respective operations, an input/output circuit 11 for processing the input information from the input information circuit 15 of respective sensors, etc., and the control outputs to respective load circuits 13 and an operation storage circuit 12 of the camera. This central control circuit 10 automatically selects the necessary oscillation circuit via the selection circuit 7 by referencing the contents of the oscillation information storage circuit 8 in accordance with the time accuracy corresponding to the kinds of the operations of the camera, the input information and the kinds of the control outputs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillator incorporated in a camera, and more particularly to various operating signals of a camera created from a plurality of oscillator signals.

[0002]

2. Description of the Related Art Conventionally, in a camera having two or more oscillation circuits inside, one oscillation circuit is used for control operation, another oscillation circuit is used for display, etc. I was trying to do it.

FIG. 3 is a block diagram of a conventional camera having an oscillator for each operating element. In the case of FIG. 3, the control device for controlling the camera circuit such as the drive circuit of the film feeding motor of the camera, the AE photometry circuit, and the shutter control circuit operates by the 4.19 MHz clock by the crystal oscillation unit 31. , A display circuit for driving the display elements LCD1 and LCD2 is provided with another crystal oscillator 32.
A separate oscillator is provided for each operating element so as to supply a Hz signal.

FIG. 4 is a block diagram of a camera having a conventional oscillator in the same element. The example of FIG. 4 is an example of an operating element configuration having a crystal oscillation unit 42 and a CR oscillation unit 41 with low oscillation accuracy in the same element, and the CR oscillation unit 41 with low oscillation accuracy is shown.
In the case of using, etc., an oscillation frequency adjusting step is provided.

[0005]

However, in the above-described conventional example, in order to achieve stable operation of the camera, as shown in FIG.
When 32 is used, or when the CR oscillation unit 41 or the like having low oscillation accuracy as shown in FIG. 2 is used, it is necessary to adjust the oscillation frequency. If a plurality of crystal oscillating units are used as shown in FIG. 1, the oscillation accuracy is guaranteed, but there is a problem that the manufacturing cost increases because the parts are expensive.

Further, as shown in FIG. 2, if a CR oscillating section or the like having low oscillation accuracy is used to reduce the cost, the unit cost of the oscillating circuit becomes low, but an extra adjusting step is required, Even if it is adjusted, there is a problem that it is easy to shift on the way.

Therefore, an object of the present invention is to automatically select operation signals having different oscillation accuracies based on the time accuracies of various operations of the camera, and to functionally correspond to each operation of the camera. It is an object to provide a camera that minimizes manufacturing costs and guarantees stable operation of the camera.

[0008]

In order to achieve the above object, the present invention as set forth in claim 1 stores a plurality of oscillating means having different frequency stability and the frequency stability accuracy of each oscillating means. Control means for controlling the camera by automatically selecting the oscillating means through the selecting means according to the required frequency stability accuracy, and the storing means, the selecting means for selecting one oscillating means from the plurality of oscillating means. The control means for performing the operation is provided.

Further, the present invention as set forth in claim 2 is provided with storage means for storing the operation of the camera in advance, and means for selecting the oscillating means in accordance with the type of camera operation stored in the storage means. ing.

Furthermore, the present invention according to claim 3 further comprises means for selecting the oscillating means according to the type of input information of the camera.

Further, the present invention according to claim 4 is provided with means for selecting the oscillating means in accordance with the type of control output of the camera.

Further, according to the present invention as set forth in claim 5, one oscillating means having a high frequency stability accuracy, a plurality of oscillating means having a lower frequency stability accuracy and a higher oscillating frequency than the oscillating means, and the frequency stability accuracy. Means for measuring the time of the signal by the oscillating means having a high frequency, means for counting the pulses of the signal by the oscillating means having the low frequency stability accuracy, and a correction value for the signal cycle having the frequency stability accuracy lower than the time measuring and pulse counting. It is equipped with a means for seeking.

Further, in the present invention as set forth in claim 6, the correction value of the signal period with low frequency stability accuracy is obtained in advance before a series of camera operations, and the control operation is performed by the correction value during the series of camera operations. Equipped with means.

Further, in the present invention as set forth in claim 7, a correction value of the signal period of the oscillation means having low frequency stability accuracy is obtained as needed during a series of camera operations, and the control operation is performed while sequentially changing the correction value. Equipped with means to do.

Further, the present invention as set forth in claim 8 is provided with means for obtaining a correction value of the signal period of the oscillating means having low frequency stability accuracy in accordance with a change in temperature and performing control while sequentially changing the correction value. ing.

[0016]

According to the camera of the present invention as set forth in claim 1, a plurality of oscillating means each having different frequency stability accuracy are provided, and the respective frequency stability accuracy is stored in the storage means, and the control means is required. Since the oscillating means is automatically selected and the control operation is performed through the selecting means according to the frequency stability accuracy, the camera oscillating operation is automatically performed by automatically selecting the oscillating means capable of meeting the required frequency stability accuracy. You can

According to the camera of the present invention as defined in claim 2, since the oscillating means is selected in accordance with the type of operation of the camera stored in the storing means in advance, the camera for film feeding or the like can be selected. It is possible to select an oscillating means having the required frequency stability accuracy depending on the type of operation.

According to the camera of the present invention as defined in claim 3, since the oscillating means is selected according to the type of the input information of the camera, the oscillation is performed according to the type of the input information such as the sensor input of the camera. The means can be selected.

According to the camera of the present invention as defined in claim 4, since the oscillating means is selected according to the type of the control output of the camera, the oscillating means is selected according to the type of the control output such as the shutter control of the camera. You can choose.

According to the fifth aspect of the camera of the present invention, one oscillation means having a high frequency stability precision and a plurality of oscillation means having a lower frequency stability precision and a higher oscillation frequency are provided to provide a high frequency stability precision. Since the correction value of the signal period of the oscillating means with low frequency stability accuracy obtained by pulse counting is calculated based on the time measurement of the signal of the oscillating means, the oscillating means with low frequency stability accuracy based on the oscillating means with high frequency stability accuracy. The signal period of the means can be corrected.

In the camera of the present invention as set forth in claim 6, the correction value of the signal period with low frequency stability accuracy is obtained before performing the series of camera operations, and the series of camera operations is controlled accordingly. , A series of camera operations can be accurately performed using corrected operation signals.

In the camera of the present invention as defined in claim 7, the correction value of the signal period with low frequency stability accuracy is obtained as needed even during the series of camera operations, and the series of camera operations are performed while updating the correction values. Since it is controlled, it is possible to accurately perform a series of camera operations for a long time.

In the camera of the present invention as defined in claim 8, the correction value of the signal period with low frequency stability accuracy is obtained according to the change of temperature, and the operation control is performed while updating the correction value. It is possible to perform an accurate camera operation that is not affected by changes in environmental conditions such as temperature changes.

[0024]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a control block diagram of a camera according to an embodiment of the present invention. In FIG. 1, a control circuit 13 including a microcomputer or the like controls the operation of the entire camera including the oscillator 9. The detection values of various sensors are input as input information from the input information circuit 15 to the central control circuit 10 via the input / output unit 11, and R is output from the central control circuit 10.
The control output calculated based on the camera operation corresponding to the AE stored in the OM 12 is sent to the various load circuits 14 such as the shutter control circuit via the input / output unit 11.

The oscillating device 9 includes oscillation circuits 1, 2 (CR oscillator), 3 (crystal oscillator) ... N, and external parts 4 (resistor R1), 5 (R) for determining oscillation constants of the oscillation circuits 1 to n.
2) and 6 (crystal oscillator X1), a frequency selection circuit 7 that selects the oscillation frequency of each of the oscillation circuits 1, 2, and 3 according to an instruction from the central control circuit 10, and each of the oscillation circuits 1 and 2, Three
The oscillation information storage circuit 8 stores the information of the frequency stability accuracy of. Although the oscillating unit is illustrated as a three-stage configuration including the CR oscillating circuits 1 and 2 and the crystal oscillating circuit 3, the oscillating unit is not limited to this and may have an n-stage configuration. Battery 16
Supplies power to the entire camera including the control circuit 13.

FIG. 2 is a detailed circuit diagram of the camera shown in FIG. Next, a detailed operation will be described with reference to FIG.
In FIG. 2, the CP of the control circuit A (corresponding to 13 in FIG. 1)
U / A16 (corresponding to the central control circuit 10 in FIG. 1) receives A / D converter A13 (input / output circuit 11 in FIG. 1) as input information.
Equivalent to), the detection signal from the photo coupler circuit F for detecting the perforation of the film, the power supply output voltage H,
Each voltage such as a detection signal of a temperature sensor circuit k such as a thermistor that detects a temperature and a detection signal of a switch input circuit G that detects a state of SW1, 2 or the like via an input interface A12 (corresponding to 11 in FIG. 1). input.

On the other hand, from the CPU A16, D / D is output as each control output referring to the camera operation stored in R0M A7.
Through the A converter A14, the output logic A11 (corresponding to the input / output circuit 11 in FIG. 1), etc., the control output of the photo coupler circuit F, the control output of the flash control circuit C, and the shutter control circuit D through the output driver A10. The control output and the control output of the drive circuit E of the film feeding motor M are sent out. Further, the display output is sent to the LCD display circuit B via the LCD driver A9. The operating states of these cameras are sequentially stored in the RAM A8. The LCD display circuit B and the switch input circuits G and A12 are always supplied with power and are in an ON state.

The oscillation section is composed of a CR oscillation circuit A1 having a high oscillation frequency and a low frequency stability precision, and a crystal oscillation circuit A2 having an oscillation frequency lower than A1 and a high frequency stability. Although the CR oscillation circuit A1 is shown as one stage, it may be configured in a plurality of stages.

Information on the frequency stability accuracy of each oscillator circuit A1 and A2 is stored in the RAM A8. Oscillation circuit A
Oscillation frequencies of 1 and A2 are automatically selected by a selection signal from the CPU A16 in a frequency selection circuit A15 formed by AND. When the CR oscillator circuit A1 is selected and the signal cycle is corrected, the crystal oscillator circuit A2 is added to the timer circuit A4.
The measurement time of the signal is set, the pulse of the signal of the CR oscillation circuit A1 is counted by the counter A3, and the correction value is calculated and stored in the RAM A8. The power supply circuit H is composed of a battery H1, a rectifying diode H3, a smoothing capacitor H4 and the like.

Power on the camera with the above-mentioned configuration.
Then, the CR oscillator circuit A1 and the crystal oscillator circuit A2 start oscillating. Since the CR oscillator circuit A1 is an oscillator circuit using a built-in capacitor and an external resistor, the frequency stability accuracy is low, but the oscillation frequency is high for high-speed processing, and the conventional adjusting circuit is not used.

Further, the crystal oscillator circuit A2 has a high frequency stability precision and a low oscillation frequency. Generally, from the cost of parts, a crystal oscillator having a low oscillation frequency to a certain extent and a large thickness is cheaper, and CR The CR for the oscillation circuit A1 has a higher frequency, is smaller and cheaper, and is easily integrated.
Regarding the oscillating operation, the CR oscillating circuit A1 is more stable when the frequency is higher to some extent.

In this embodiment, these two oscillator circuits are analyzed in detail for the type of camera operation and the time accuracy of the input / output state.
Effectively and properly operating so as to correspond to them, reflecting them in the configuration of the oscillation circuits A1 and A2 to reduce the cost, and at the same time, constructing efficient and accurate operation control by functionally corresponding to each operation of the camera. This is the main purpose.

Among the operations of the camera, there are operations that can be processed even with a clock having a low frequency, and operations that can be processed at high speed without requiring high precision. For example, the photocoupler circuit F is a sensor that detects the running state of the film. But,
The moving speed of the film is 50mm / sec-10mm
Since it is slow, such as / sec, it can be processed with a slow clock. Therefore, the RAM and RO that store these operations
Since the crystal oscillation circuit A2 or the lower CR oscillation circuit A1 can be automatically selected from the state of M, the processing clock can be lowered.

Further, since the input of the switch circuit G is also a part operated by a human, the processing speed is about 100 mse.
The processing clock can be lowered in the same manner as in the case of c. The same is true when the motor is driven and a simple energization is performed without controlling the rotation speed of the motor. If the processing clock can be lowered, the intermediate processing of time control becomes easier, and the configuration of the processing circuit can be inexpensive.

Further, when the CR oscillation circuit A1 having a high oscillation frequency but a low frequency stability precision is used, the correction is performed based on the signal period of the crystal oscillation circuit A2 having a high frequency stability precision. In the signal cycle correction procedure, first, the timer A9 is set to start and stop the counting of the counter A3 with the clock of the crystal oscillation circuit A2 having the higher frequency stability accuracy. The number of pulses of the CR oscillator circuit A1 included in the set time is counted. Assuming that the count number at that time is m, this m is the same as the predicted value M, that is, in the case of an ideal circuit with no oscillation frequency error, the correction value K is "1", and the correction value K = m / M,
Is represented by

For example, the design value of the CR oscillation circuit A1 is 40.
0 KHz, the oscillation frequency of the crystal oscillation circuit A2 is 32.76.
If it is 8 KHz (By the way, 32.768 KHz is the frequency for the display circuit of the conventional example, the higher frequency of 400 KH
z corresponds to a little over 1/10 of 4.19 MHz), 16 clocks of the crystal oscillation circuit A2, that is, 48.828 ms.
The oscillation frequency of the CR oscillation circuit A1 is about 195
Since pulses are generated, the correction value K = 1 when 195 pulses are counted, and the K value is proportionally changed when the number is deviated from that. In practice, assuming that the value predicted by the design value is 1, the correction value K will normally change by about ± 50% due to the accuracy of circuit components, operating conditions, etc., if no adjustment is made. It changes about "0.5-1.5".

Since the shutter operation of the camera is a highly time-sensitive operation that requires time accuracy, the counter A3 performs pulse counting before the shutter operation to obtain the correction value K and store it in the RAM-A8. Every time, the time from the start of the shutter operation to the stop at the predetermined shutter speed is controlled by the number of pulses corrected by “K”.

As described above, when performing high-speed processing with high time accuracy such as shutter control at the frequency of the CR oscillation circuit A1, the correction value K is obtained in advance before a series of operations (shutter operation in this case). And perform accurate control operation.

When the series of operations is long in time, for example, the operations of the display circuit and the switch input circuit, the correction value K is recalculated at predetermined time intervals, and R is calculated during the series of operations.
Rewriting "K" while rewriting the "K" value in AMA8
The control operation is performed to maintain accuracy.
Further, the oscillation frequency is also influenced by manufacturing processing conditions, changes in operating environment, temperature, humidity, etc., so that “K” changes.

Therefore, the correction in these cases is, for example, C
Since the oscillating frequency of the R oscillating circuit A1 is apt to change particularly due to temperature change, when the detected value of the temperature sensor circuit k exceeds the threshold value set above and below the reference room temperature of 25 degrees, The CPU A16 converts the temperature detection current of the sensor circuit k into a voltage by the amplifier A19, inputs it through the A / D converter A13, and if the threshold value is exceeded in the judgment processing, the "K" value is calculated again and updated. To do so.

In addition, in order to reduce the power supply current consumption of the battery, it is necessary to minimize the circuit consumption current, and the operation of the LCD display circuit B or the like which constantly consumes current is
It is necessary to select a circuit having an oscillation frequency as low as possible without selecting an oscillation circuit having a high oscillation frequency within a required drive pulse allowable range.

In order to judge the state of the power supply battery,
A low current load circuit is connected to the battery output for a certain period of time, and the voltage at that time is detected via the A / D converter A13. If the battery voltage drops below a certain value, a malfunction such as data loss may occur. It is easy to do so, so program it to automatically select the lower oscillation circuits and lower the operation clock. As described above, in the present embodiment, the signal of the CR oscillation circuit having low frequency stability accuracy is configured to be used for correction with reference to the signal period of the crystal oscillation circuit having high frequency stability accuracy. Can be synchronized with the signal cycle of the crystal oscillation circuit, and the reliability of the camera system can be improved.

In the above embodiments, the automatic selection operation of the oscillation circuit corresponds to claims 1 to 4, and the correction processing of the signal period corresponds to claims 5 to 8.

Further, the correction control of the signal cycle by the correction value "K", taking the operation control of the shutter circuit D as an example,
This corresponds to the operation of the means described in claim 6.

Further, the continuous correction control of the signal cycle by updating the correction value "K", taking the operation control of the LCD display circuit B as an example, corresponds to the operation of the means described in claim 7.

Further, based on the detected value of the temperature sensor circuit k,
The correction control for updating the correction value “K” corresponds to the operation of the means described in claim 8.

[0048]

As described above, the camera of the present invention as set forth in claim 1 is provided with a plurality of oscillating means having different frequency stability precisions and stores the respective frequency stability precisions.
Equipped with control means that automatically selects the oscillation means through the selection means according to the required frequency stability accuracy to control the camera, so that the oscillation means that automatically responds to the required frequency stability accuracy is automatically selected. By doing so, it is possible to omit the adjustment process, reduce the cost, and ensure the stable operation of the camera.

Further, in the camera of the present invention as defined in claim 2, since the oscillating means is selected in accordance with the type of camera operation stored in the storage means in advance, it is necessary depending on the type of operation of the camera. By automatically selecting the oscillating means having the frequency stability accuracy, it is possible to reduce the influence of harmonic noise and the like without activating the extra oscillating means.

Furthermore, since the camera of the present invention as defined in claims 3 and 4 is configured to select the oscillating means according to the type of input information or control output of the camera, the type of input information or control output can be selected. Correspondingly, by automatically selecting the oscillating means, it is possible to reduce the current consumption and enable the input / output standby state and the display output for a long time.

Further, in the camera of the present invention as set forth in claim 5, based on the time measurement of the signal of the oscillating means having a high frequency stability accuracy, the correction value of the signal period of the oscillating means having a low frequency stability accuracy counted by pulse counting is obtained. Since it is configured to calculate, the signal of the oscillation means with low frequency stability accuracy is used for the control operation with high time accuracy by correcting the signal period with low frequency stability accuracy based on the signal of the oscillation means with high frequency stability accuracy. It is possible.

Furthermore, the camera of the present invention as defined in claim 6 is configured to obtain a correction value of a signal period with low frequency stability accuracy before performing a series of camera operations and control the series of camera operations. By correcting the camera before performing a series of operations, more precise time control is possible.

Further, in the camera of the present invention as defined in claim 7, since the operation control is performed while updating the correction value of the signal period with low frequency stability accuracy during a series of camera operations, a long time is required. It is possible to guarantee the operation of a series of camera operations.

Further, in the camera of the present invention as defined in claim 8, since the operation value is controlled while updating the correction value of the signal period having low frequency stability accuracy according to the temperature change, By detecting the predicted oscillation frequency fluctuation factor in advance and performing the correction process, it is possible to obtain the effect of shortening the processing time.

[Brief description of drawings]

FIG. 1 is a control block diagram of a camera according to an embodiment of the present invention.

FIG. 2 is a detailed circuit diagram of the embodiment shown in FIG.

FIG. 3 is a block diagram of a camera having a conventional oscillator for each operating element.

FIG. 4 is a block diagram of a camera having a conventional oscillator in the same element.

[Explanation of symbols]

 1, 2 CR oscillation circuit 3 Crystal oscillation circuit 4, 5 External resistor 6 External crystal oscillator 7 Selection circuit 8 Oscillation information storage circuit 9 Oscillation device 10 Central control circuit 11 Input / output circuit 12 Camera operation storage circuit 13 Control circuit 14 Load circuit 15 Input information circuit 16 Battery

Claims (8)

[Claims] 1. A plurality of oscillating means each having different frequency stability accuracy, a storage means for storing the frequency stability accuracy of each oscillating means, and a selecting means for selecting one oscillating means from the plurality of oscillating means. And a control means for automatically selecting the oscillating means via the selecting means in accordance with the required frequency stability accuracy to control the camera. 2. The camera according to claim 1, further comprising a storage unit that stores the operation of the camera in advance, and a unit that selects the oscillation unit according to the type of the camera operation stored in the storage unit. A camera characterized by. 3. The camera according to claim 1, further comprising means for selecting the oscillating means according to a type of input information of the camera. 4. The camera according to claim 1, further comprising means for selecting the oscillating means according to the type of control output of the camera. 5. A single oscillator having high frequency stability precision, a plurality of oscillators having lower frequency stability precision and higher oscillation frequency than the oscillator, and time measurement of a signal by the oscillator having high frequency stability precision. Means for performing pulse counting of signals by the oscillating means having low frequency stability precision, and means for obtaining a correction value of the signal period having low frequency stability precision from the time measurement and pulse counting. And the camera. 6. The camera according to claim 5, further comprising means for obtaining a correction value of the signal period with low frequency stability accuracy in advance before a series of camera operations and performing a control operation by the correction value during the series of camera operations. A camera that is equipped with. 7. The camera according to claim 5, wherein a correction value of a signal period of the oscillating means having low frequency stability accuracy is obtained as needed during a series of camera operations, and the control operation is performed while sequentially changing the correction value. A camera characterized by having. 8. The camera according to claim 5, further comprising means for obtaining a correction value of a signal period of the oscillating means having low frequency stability accuracy in accordance with a change in temperature and performing a control operation while sequentially changing the correction value. A camera characterized by that.