JP3927657B2 - Cameras and electronic devices - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera and an electronic device, and more particularly to the reliability of a camera battery check.
[0002]
[Prior art]
In recent years, the development of electronic devices has been remarkable, and electronic devices with particular emphasis on portability are becoming smaller and lighter. In order to reduce the size and weight of the batteries that operate these electronic devices, batteries that lower the battery voltage or sacrifice internal resistance to some extent have appeared.
[0003]
Cameras are becoming more and more compact, and such batteries are being actively adopted. When such batteries are used, when batteries are exhausted or when batteries with high internal resistance are used, or Immediately after energizing the large current load, a considerable time is required for the power supply voltage to recover. For example, when a strobe is charged, a considerable load is supplied from the battery, so that the battery voltage temporarily decreases. Thereafter, the battery voltage recovers over several tens of seconds to several minutes.
[0004]
Therefore, in a camera using such a battery, once the flash is charged, the battery voltage temporarily decreases for a few minutes, and the battery used at that time is already present. If the battery is depleted to some extent, it will reach the battery check voltage that guarantees normal operation of the camera at that time. After a while, even if the battery recovers, the battery can be used normally, but a state where it cannot be used generally occurs, and the operability is remarkably lowered.
[0005]
Further, in a camera having a display means, a battery warning display is further displayed, which confuses the user.
[0006]
In order to avoid such a phenomenon, for example, Japanese Utility Model Publication No. 56-1567317 discloses a method of selecting a reference voltage to be compared with a power supply voltage from a plurality of reference voltages for each of a plurality of photographing modes. Yes.
[0007]
[Problems to be solved by the invention]
However, in the above conventional example, Japanese Utility Model Laid-Open No. 56-1567317 is a method of selecting a reference voltage to be compared with a power supply voltage from a plurality of reference voltages for each of a plurality of shooting modes. When the mode is selected, there is a problem that it can be easily imagined that the same drawbacks as in the conventional case occur in the same way.
[0008]
In addition, Japanese Utility Model Publication No. 2-47631 discloses a related prior art, in which a battery check is performed at the time of strobe charging so that a battery is displayed as a sufficient display regardless of the battery voltage. However, in this case, even when the battery voltage is really lowered and normal operation cannot be expected, there is a problem in that the user is misunderstood because the display indicates that the battery is sufficient.
[0009]
In Japanese Patent Laid-Open No. 4-50935, as a related prior art, a driving mode with a large load is selected by a camera capable of selecting a driving mode with a large load on the actuator and a driving mode with a small load. In this case, a variable control method has been proposed in which a higher value is set as a reference voltage for comparison than when a drive mode with a small load is selected. This also depends on the actual battery type and condition. There is a problem that it is difficult to say that it is highly variable control.
[0010]
SUMMARY OF THE INVENTION Accordingly, an object of the invention described in claim 1 is to improve the reliability of battery check and warning display in order to eliminate the conventional problems, and to have a battery check system having excellent operability in consideration of battery characteristics. Is to provide a camera.
[0011]
Furthermore, an object of the invention described in claim 2 is to provide a battery check type camera having excellent operability in consideration of the characteristics of the battery while improving the reliability of the battery check and warning display after the strobe charging operation. There is to do.
[0012]
Furthermore, an object of the invention described in claim 3 is to provide a battery check type camera having improved operability in consideration of battery characteristics, while improving the reliability of battery check and warning display without being affected by temperature. It is to provide.
[0013]
Furthermore, an object of the invention described in claim 4 is to provide a battery check type camera having an excellent operability in consideration of the characteristics of the battery while improving the reliability of the battery check and the warning display irrespective of the degree of consumption of the battery. It is to provide.
[0014]
Furthermore, an object of the invention described in claim 5 is to improve the reliability of battery check and warning display regardless of the type of battery used in the camera, and to have a battery check system having excellent operability in consideration of battery characteristics. Is to provide a camera.
[0015]
Further, an object of the present invention is to provide a camera capable of accurately detecting whether or not a large load has been supplied in advance for switching the reference voltage.
[0016]
Furthermore, an object of the present invention is to provide a camera that improves the reliability of battery check by accurately detecting the type of battery used and switching the reference voltage.
[0017]
[Means for Solving the Problems]
The configuration for realizing the object of the invention according to the present application is, as described in claim 1, a plurality of loads supplied with power from a battery, a plurality of modes for performing predetermined energization for each load, Battery voltage detecting means for detecting the voltage of the battery; reference voltage setting means capable of setting a first reference voltage value and a reference voltage value lower than the first reference voltage value; and the detected battery voltage and the reference voltage setting means. A comparison means for comparing the outputs of the cameras, a storage means for storing information relating to the operation mode of the camera executed immediately before, a timing means for measuring an elapsed time since execution of the operation mode of the immediately preceding camera, and a timing means And a time setting means for setting a power time, and in a camera that prohibits or warns the operation according to the output of the comparison means, the output of the reference voltage setting means according to the stored contents of the storage means In camera, wherein a switch only time set by the time setting means.
[0018]
According to this configuration, the output of the reference voltage setting means is switched only for the time set by the time setting means in accordance with the contents stored in the storage means, and the battery check and the accurate warning display that accurately correspond to the battery state It can be performed.
[0019]
A specific configuration for realizing the object of the invention according to the present application is the camera according to claim 1, wherein one of the plurality of operation modes is a strobe charging operation. is there.
[0020]
According to this configuration, it is possible to perform a battery check corresponding to the state of the battery immediately after strobe charging and an accurate warning display.
[0021]
According to another specific configuration for realizing the object of the present invention, the output of the reference voltage setting means or the output of the time setting means is variable according to the temperature. The camera according to claim 1, wherein:
[0022]
According to this configuration, it is possible to perform a battery check corresponding to the state of the battery due to a temperature change and an accurate warning display.
[0023]
According to another specific configuration for realizing the object of the present invention, the output of the reference voltage setting means or the output of the time setting means depends on the output of the battery voltage detection means. The camera according to claim 1, wherein the camera is variable.
[0024]
According to this configuration, an accurate battery check and warning display corresponding to the output of the battery voltage detection means can be performed.
[0025]
According to another specific configuration for realizing the object of the present invention, the output of the reference voltage setting means or the output of the time setting means is variable according to the type of battery. The camera according to claim 1, wherein:
[0026]
According to this configuration, it is possible to detect the battery type and perform a battery check corresponding to the battery type and an accurate warning display.
[0027]
According to another specific configuration for realizing the object of the invention according to the present application, as described in claim 6, the information regarding the operation mode of the camera immediately before being stored in the storage means is strobe charged indicating strobe charging. 5. The camera according to claim 1, wherein the bit is a film rewinding bit indicating film rewinding and a progressing bit indicating time passage.
[0028]
According to this configuration, a large load supply operation of strobe charging or a predetermined amount of film rewinding is performed, and an elapsed time after the execution is surely detected to correspond to the state of the battery immediately after the large load supply is performed. Battery check and accurate warning display can be performed.
[0029]
According to another aspect of the present invention for realizing the object of the present invention, as described in claim 7, the type of the battery detects whether it is an internal battery or an external battery by a battery type detecting means. The camera according to claim 5.
[0030]
According to this configuration, it is possible to accurately detect whether the battery is a small battery to be loaded in the camera or a large battery to be mounted outside, and a corresponding battery check and an accurate warning display can be performed.
[0031]
According to another aspect of the present invention for realizing the object of the present invention, in an electronic device including a load to which power is supplied from a battery, a voltage detection unit that detects a voltage of the battery, Determining means for comparing the detected voltage with the first reference voltage to determine a battery state; and setting the reference voltage to a second reference voltage lower than the first within a predetermined time after driving the load. The electronic device is characterized by the following.
[0032]
According to this configuration, it is possible to perform a battery check and an accurate warning display according to the state of the battery.
[0033]
According to another aspect of the present invention for realizing the object of the present invention, as set forth in claim 9, the reference voltage is set to a voltage higher than the second reference voltage after a predetermined time has elapsed. Item 8 is an electronic device according to item 8.
[0034]
According to this configuration, accurate battery check and warning display are possible.
[0035]
According to another aspect of the present invention for realizing the object of the present invention, according to claim 10, when the load driving amount is smaller than a predetermined amount, the reference voltage is set according to the load driving amount. 10. The electronic apparatus according to claim 8, wherein setting to a reference voltage of 2 is prohibited.
[0036]
According to this configuration, the reference voltage can be set to one.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
1 to 5 are diagrams according to the first embodiment of the present invention.
FIG. 1 is a block diagram of a camera according to the first embodiment of the present invention.
FIG. 2 is a diagram showing fluctuations in battery voltage of the camera shown in FIG.
FIG. 3 is a flowchart of the operation of the camera shown in FIG.
FIG. 4 is a flowchart of the operation when the operation switch of the camera shown in FIG. 1 is pressed.
FIG. 5 is a flowchart of the operation when the watch timer of the camera shown in FIG. 1 is interrupted.
[0038]
In FIG. 1, 1 is a CPU for controlling the sequence of the entire camera, 2 is an A / D converter built in the CPU 1, 3 is a temperature detecting means for outputting an analog signal proportional to temperature, and 4 is a battery voltage of the camera. Battery voltage detecting means for outputting a corresponding analog signal, 5 is an information display means for displaying the state of the camera, 6 is a high speed oscillator for operating the CPU 1, 7 is a low speed oscillator for the CPU 1 to control time and clock functions, Reference numeral 8 denotes a strobe circuit of the camera that inputs a divided output of the charging voltage of the main capacitor to the A / D converter 2. 9 is a film feeding motor, 10 is a film feeding means for winding and rewinding the film by the motor 9, 11 is an exposure control means for exposure, 12 is an EEPROM for storing adjustment data for each camera, and 13 is The switch detection means 14 for detecting the operation switch and the state detection switch 14 is a DC / DC converter for boosting the battery voltage.
[0039]
First, the DC / DC converter 14 is activated to enable the high-speed operation of the CPU 1 and the operation of the A / D converter 2. Thereafter, the output of the temperature detecting means 3 is A / D converted by the A / D converter 2 built in the CPU 1 to obtain temperature information. Next, the output of the battery voltage detection means 4 is A / D converted to obtain battery voltage information. In general, in order to obtain more accurate information on the battery at this time, a predetermined current is supplied to a load in the camera (for example, energization in a closing direction of a shutter (not shown)), and the battery voltage is set to A during this energization. Battery voltage information including the influence of the output impedance of the battery is obtained by / D conversion.
[0040]
In general, when this voltage drops to a voltage that cannot guarantee the operation of the camera, or to an operation prohibiting voltage, the CPU 1 controls the camera so that the operation of the camera is prohibited to prevent malfunctions or possible malfunctions. To do.
[0041]
In addition, in a camera having a display means, when the battery voltage decreases to an operation warning voltage that is higher than the operation prohibition voltage of the camera, a warning display is displayed on the display means to recommend the user to replace the battery. Some cameras are designed to be released.
[0042]
The A / D converter 2 has an input range of 0 to 2.5 V and a resolution of 8 bits. If the battery is a 3V battery, the battery voltage detecting means 4 outputs the battery voltage divided by resistance on a one-to-one basis, and outputs a value ½ of the battery voltage to the A / D converter 2. That is, for example, if the battery voltage at the time of battery check is 2.5V, the output of the battery voltage detection means 4 is 1.25V, and the CPU 1 obtains 80H as a result of A / D conversion.
[0043]
Here, if the voltage for determining whether or not to prohibit the operation is 70H when the battery check is performed with the first reference voltage value, that is, the current battery voltage in a steady state, the battery at the time of battery check When the voltage is (2.5V / 256) × 70H × 2 = 2.19V or less, the CPU 1 determines that the normal operation of the camera is impossible, and sets the information display means 5 to the operation prohibited state. Display is performed, and the subsequent operation (shutter drive or the like) is not performed, and a state of waiting for the operation switch to be pressed again is entered.
[0044]
This is an operation prohibition state. When the operation switch is pressed again, a battery check is performed. If the operation prohibition voltage is exceeded, operation is possible, and no camera operation is performed unless the operation prohibition voltage is exceeded.
[0045]
Next, when the release switch is operated and the battery check results in that the battery voltage is sufficient to execute the camera operation, the camera sequence proceeds and the strobe is charged. Is supplied to the capacitor in the strobe circuit 8, the battery voltage drops considerably during charging. Therefore, once the charging operation is stopped, and then there is no other heavy load, the battery voltage once lowered gradually recovers. This is shown in FIG.
[0046]
In a conventional battery having a large external shape, the internal resistance of the battery is small, so that the voltage drop during charging is relatively small, and the battery voltage recovery time after completion of charging is also fast. On the other hand, in recent miniaturized batteries, the internal resistance is large, so the voltage drop during charging is large and the recovery time after completion of charging is also long.
[0047]
Furthermore, when this battery is placed at a low temperature, both the internal resistance and the recovery time change in a direction that increases. That is, it can be seen that if the battery check is performed again until the time T1 after the charging operation is stopped, the battery voltage is lower than the first reference voltage, and thus the operation is prohibited. Similarly, if the battery is miniaturized, until the time T2 after the charging operation is stopped, and if the battery temperature is lower, the battery check is executed until the time T3 after the charging is stopped. I understand.
[0048]
Certainly, at this point, the battery voltage has actually dropped, but this is because the battery voltage has dropped temporarily due to the supply of a heavy load. It's not a mess. Therefore, in order to improve the operability without impairing the reliability of the battery check when operating the camera using such a battery that is known to recover after a while, in this embodiment, the camera Focusing on the charging operation of the strobe with the highest load among the operations, if the charging operation of the strobe is executed, the information is stored and the reference voltage of the battery check is set until the fixed time elapses. The reference voltage is changed to a reference voltage lower than 1. That is, when the battery check operation is performed again within a predetermined time after the completion of the strobe charging, the follow-up control that permits the operation of the camera up to a battery voltage lower than the normal operation inhibition voltage is adopted.
[0049]
Next, the operation will be described with a focus on the flowchart of FIG. In the following flowcharts, “S” represents a step.
[0050]
First, the current charging voltage of the main capacitor is A / D converted (S101). If the strobe is not emitting light after the previous charge, the main capacitor should have enough charge, and the strobe can emit light with a slight supplementary charge. In this case, the main capacitor is empty. Since charging is completed with much less energy than when charging is started from this state, such a case is detected because it does not fall under the heavy load considered in this embodiment. Therefore, the charging voltage detection procedure is performed.
[0051]
If this charging result is below a predetermined amount, a large amount of energy is supplied from the battery in the subsequent charging operation, and if it is above the predetermined amount, nothing is done.
[0052]
Next, the result of the A / D value is determined (S102). Here, the A / D conversion result is converted into the main capacitor voltage of the strobe, and it is determined whether or not the result is larger than 50V, for example.
[0053]
If the voltage is 50 V or less, a large load is supplied in the subsequent charging process. In order to store this, a predetermined bit (referred to as a strobe charged bit) at a predetermined address in the EEPROM 12 is set to 1. (S103).
[0054]
A charge start command is output to the strobe circuit 8 (S104). When the charging voltage of the main capacitor reaches a predetermined voltage set in the strobe circuit, the strobe circuit stops charging and outputs to the CPU 1 that the charging voltage has reached the predetermined voltage. After outputting the charge start command, the CPU 1 waits for a charge completion signal (S105). At this point, it is actually necessary to prepare for a case where the charge completion signal is not output within a predetermined time for safety reasons, but it is omitted here for simplification.
[0055]
If a charging completion signal is detected, the flash charging sequence is completed. Thereafter, the focus lens control, shutter control, etc. are performed as necessary, and the flash emission sequence is performed to capture one frame. Complete.
[0056]
Next, the state after waiting for the next switch operation upon completion of photographing or charging of the strobe will be described with reference to the flowchart of FIG.
[0057]
Wait for the operation switch to change. At this time, the CPU 1 is set so as to accept an interrupt of the clock counter timed by the low-speed clock (S110). In this state, a change occurs in the operation switch, and when the CPU 1 is activated, a predetermined operation is performed according to the operated switch. In that case, a battery check is first performed.
[0058]
In a state where a predetermined load is energized, the battery voltage is measured by the battery voltage detection means 4 by A / D conversion (S111). Next, the A / D conversion result is compared with a reference voltage to determine whether or not to prohibit the operation. Before that, information on the flash charged bit of the EEPROM 12 is read (S112).
[0059]
It is determined whether or not the result read from the EEPROM 12 is set to 1 (S113). In the case of 0, since the large load of charging the strobe is not performed immediately before, it is determined that the battery voltage is sufficiently in a steady state, and the first reference voltage of the battery voltage is used as the comparison reference voltage. It is assumed that the reference voltage 70H is used (S114).
[0060]
If it is set to 1, the strobe has been charged immediately before, and it is determined that the battery voltage is temporarily reduced at present, and the first reference value 70H to 10H is used as the battery voltage comparison reference value. Is set to 60H (S115).
[0061]
In this way, the reference voltage set in S114 and S115 is compared with the battery voltage which has been A / D converted previously (S116). When 70H is set as the reference voltage, the operation inhibition voltage is 2.19V as previously obtained. However, when 60H is set as the reference voltage, (2.5V / 256) × 60H. X2 = 1.88V, and the operation inhibition voltage is 1.88V.
[0062]
If the battery voltage is higher than any of the previously set reference voltages, it is determined that the camera is operable, and the camera sequence corresponding to the operation switch is executed (S117).
[0063]
If it is determined that the battery voltage does not reach any of the reference voltages, it is determined that the camera does not function normally, the information display means 5 is displayed as being prohibited, and the process returns to S110 (S118).
[0064]
Next, processing when an interrupt is generated by the clock counter will be described with reference to the flowchart of FIG.
[0065]
Now, the camera measures time with the low-speed oscillator 7 and displays clock information on the information display means 5. For this purpose, when the clock counter interrupts, the clock data stored in the RAM (not shown) and the elapsed time of the clock timer are added and written again in the RAM (S120).
[0066]
Next, as a result of updating the clock data, it is determined whether or not the display means needs to be rewritten (S121). In general, the clock information displays the date, date and time, and in this case, when the “minute” of the clock is increased, the clock display of the display means is updated. There is a need.
[0067]
Therefore, if the display needs to be updated, the display is updated (S122). Since the clock counter interrupt generally occurs in a time shorter than one minute, it is necessary to rewrite the display once every tens of timer interrupts. In the present embodiment, it is determined whether or not the display needs to be updated, that is, whether or not 1 is set to the flash charged bit of the EEPROM 12 every minute.
[0068]
That is, the flash charged bit of the EEPROM 12 is read (S123), and it is determined whether or not the flash charged bit is set to 1 (S124). If the strobe charged bit is not set to 1, there is no history of charging the strobe immediately before, so the interrupt process is terminated without doing anything.
[0069]
On the other hand, if the strobe charged bit is set to 1, the elapsed bit for recording the elapsed time after detecting the strobe charged bit in the specific bit of the predetermined address of the EEPROM 12 is read (S125). That is, if this elapsed bit is 0, it indicates that the strobe charged bit is set to 1 after the previous clock timer interruption, that is, within 1 minute after the strobe charging, and if this elapsed bit is 1. For example, it can be determined that it is 1 minute or more and 2 minutes or less after the flash charging.
[0070]
Therefore, it is determined whether or not the progress bit is 1 (S126). If the elapsed bit is 1, it is determined that the battery voltage has recovered since at least one minute has elapsed since the flash charging, and the flash charged bit is reset to 0 and the elapsed bit is also set to 0. Reset (S127).
[0071]
If the elapsed bit is 0, it is determined that the battery voltage has not recovered since 1 minute has not yet passed, and the elapsed bit is set to 1 to wait for another 1 minute to elapse. Then, the interrupt process is finished (S128).
[0072]
Thus, according to the present embodiment, when the strobe circuit 8 performs a charging operation of a predetermined value or more from the above procedure, at least 1 minute after the start of the charging operation and until a maximum of 2 minutes elapses. Lowers the battery check reference voltage below the normal reference voltage, reducing the probability that a battery that has a sufficient remaining capacity for normal operation and temporarily dropped after charging will be prohibited from operating. It becomes possible to improve.
[0073]
On the other hand, if the battery is really exhausted, even if the reference voltage is temporarily lowered after checking the flash, the battery voltage will drop further, so it will be temporarily disabled and used. If the battery is low, and if the battery is further lowered, the operation prohibition state is determined based on the same reference value as the normal battery check if a maximum of 2 minutes or more has elapsed after the flash is charged. Check reliability is not compromised.
[0074]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is a flowchart of the film rewinding operation of the camera according to the second embodiment of the present invention.
FIG. 7 is a flowchart of the operation when the operation switch of the camera shown in FIG. 6 is pressed.
FIG. 8 is a flowchart of the operation when the watch timer interrupt of the camera shown in FIG. 6 occurs.
[0075]
Note that the block diagram shown in FIG. 1 is common to the second embodiment. 2 and 3 are also common, and redundant description of the configurations of FIGS. 1 and 2 is omitted.
[0076]
In the first embodiment, only strobe charging is considered as a heavy load. However, as the operation of the camera, the energization operation to the motor or the like is a large load although it is small compared to the charging of the strobe circuit. Especially in zoom cameras that have recently been miniaturized, the DC resistance of the motor is in the direction to be lowered in order to obtain the same level of motor power as the battery and the motor. The current during energization is increasing.
[0077]
In the second embodiment, when the charging operation of the strobe is executed by paying attention to the charging operation of the strobe with the largest load among the operations of the camera and the rewinding operation of the film considered to have the next largest load. Stores the information, changes the battery check reference voltage to a second reference voltage lower than the first reference voltage until a certain time after execution, and executes a film rewinding operation. The information is stored, and the battery check reference voltage is changed to a third reference voltage lower than the first reference voltage until a predetermined time elapses after execution.
[0078]
In other words, if the battery check operation is performed again within a certain time after the completion of strobe charging or within a certain time after the film rewinding operation is performed, the camera operation is allowed to a battery voltage lower than the normal operation prohibiting voltage. To do.
[0079]
In the second embodiment, the A / D converter 2 is the same as that in the first embodiment, and the first reference voltage of the battery check is the same as that in the first embodiment.
[0080]
Next, the operation will be described.
[0081]
First, since the operation of strobe charging is exactly the same as that of the first embodiment shown in FIG. 3, the redundant description will be omitted, and the operation at the time of film rewinding shown in the flowchart of FIG. 6 will be mainly described.
[0082]
When the number of shots reaches the specified number of films, or when the user presses the rewind button halfway, the film rewinding operation is started.
[0083]
The number of frames of the current film before the start of rewinding is detected (S130). This is to detect these values in order to detect such a case because there is no heavy load when the number of rewinds is very small, such as when the rewind button is pressed halfway. is there.
[0084]
Next, the number of frames to be rewound is calculated (S131). That is, the number of frames to be rewound by the rewinding operation can be calculated from the specified number of films read at the time of film loading and the current number of film shots. If the number of frames is equal to or greater than a predetermined number (for example, 15 frames or more in the second embodiment), it is determined that the load is large and this state is stored.
[0085]
That is, a predetermined bit (referred to as a film predetermined amount rewinding bit) at a predetermined address in the EEPROM 12 is set to 1 (S132). On the other hand, if the number of frames is equal to or less than the predetermined value, nothing is done and the film feeding motor 9 is driven by the film feeding means 10 to start the film rewinding operation (S133).
[0086]
Next, it is determined whether or not the film has been rewound normally (S134). Actually, the stricter film rewinding operation is confirmed and displayed, but since it is not directly related to the present invention, it is omitted here. If it is determined in S134 that the film has been rewound normally, the control of the film feeding means 10 is stopped and the operation of the film feeding motor 9 is stopped (S135).
[0087]
Thus, the film rewinding operation is completed, and thereafter, the information display means 5 displays that the rewinding operation is completed as necessary, and waits for the rewinding film to be taken out.
[0088]
Next, the state after waiting for the switch operation will be described with reference to the flowchart of FIG.
[0089]
It waits for the operation switch to change (S140). At this time, the CPU 1 is set to accept an interrupt of a clock counter that is timed with a low-speed clock.
[0090]
In this state, a change occurs in the operation switch, and when the CPU 1 is activated, a predetermined operation is performed according to the operated switch. In that case, a battery check is first performed.
[0091]
In a state in which a predetermined load is energized, the battery voltage detection means 4 measures the battery voltage by A / D conversion (S141). Next, the A / D conversion result is compared with a reference voltage to determine whether or not the operation is prohibited. Before that, information on the flash charged bit in the EEPROM 12 is first read (S142).
[0092]
It is determined whether or not the result of the strobe charged bit read from the EEPROM 12 is set to 1 (S143). If it is set to 1, the strobe is being charged immediately before, and it is determined that the battery voltage is temporarily reduced at present, and the reference voltage to be compared with the A / D conversion result of the battery voltage As a result, 60H obtained by subtracting 10H from the first reference voltage 70H is set (S145).
[0093]
In this case, since the load due to the stroboscopic charge is larger than the rewinding load of the film, it is judged that the influence of rewinding the film is sufficiently small, and the predetermined amount of rewinding bit of the film is checked. Instead, perform the following steps:
[0094]
On the other hand, if the strobe charged bit remains 0, it is determined that the strobe has not been supplied with a large load just before the strobe is charged, and a predetermined film rewind bit is checked (S144). Here, if the film predetermined amount rewinding bit is 1, it is determined that the film voltage has been temporarily rewinded by a certain amount immediately before the rewinding of the film more than a predetermined amount, The voltage is lowered from the first reference voltage 70H and set to 68H (S146). On the other hand, if the film predetermined amount rewind bit is 0, it is determined that the battery voltage is sufficiently in a steady state, and the first reference voltage 70H is used as the reference voltage (S147).
[0095]
Thus, the reference voltage set in S145, S146, and S147 is compared with the battery voltage that has been A / D converted previously (S148). When the reference voltage is set to 70H, the operation prohibition voltage is 2.19V as previously obtained, but when the reference voltage is set to 60H, (2.5V / 256) × 60H × 2 = 1.88V and the operation inhibition voltage is 1.88V.
[0096]
When 68H is set as the reference voltage, (2.5V / 256) × 68H × 2 = 2.03V, and the operation inhibition voltage is 2.03V.
[0097]
If it is determined in S148 that the battery voltage is larger than any of the previously set reference voltages, the camera is determined to be operable and the camera sequence corresponding to the previously operated operation switch is executed. (S149). If it is determined in S148 that the battery voltage does not reach any of the reference voltages, it is determined that the camera does not function normally, and the information display means 5 is displayed indicating that the operation is prohibited, and S140 is displayed. Return to (S150).
[0098]
Next, processing when an interrupt is generated by the clock counter, which has been previously set during this sequence, will be described with reference to the flowchart shown in FIG.
[0099]
Now, the camera measures time with a low-speed oscillator and displays clock information on the information display means 5. For this reason, when a clock counter interrupt occurs, the clock data stored in the RAM (not shown) and the elapsed time of the clock timer are added and written again in the RAM (S160).
[0100]
Next, it is determined whether or not the display means needs to be rewritten as a result of updating the clock data (S161). In general, the clock information displays the date and time, and the date and time, so in this case, if the “minute” of the clock increases, the clock display on the display means needs to be updated. is there. Therefore, if an update is necessary, the display is updated (S162). Since a clock counter interrupt generally occurs in a time shorter than one minute, it is necessary to rewrite the display once every tens of timer interrupts.
[0101]
If it is necessary to update the display, it is determined whether 1 is set to the flash charged bit and the predetermined film rewind bit of the EEPROM 12 every minute. That is, the flash charged bit and the predetermined film rewinding bit of the EEPROM 12 are read (S163), and it is determined whether or not any of the bits is set to 1 (S164).
[0102]
Here, if none of the bits is set to 1, since there is no history of charging the strobe or rewinding the film immediately before, the interrupt processing is finished without doing anything. On the other hand, if any one of the bits is set to 1, the elapsed bit is recorded, in which the elapsed time since the detection of any bit is recorded in a specific bit at a predetermined address of the EEPROM 12 is read (S165).
[0103]
That is, if this elapsed bit is 0, it indicates that any bit has been set to 1 after the previous clock timer interrupt, that is, within 1 minute after strobe charging or within 1 minute after film rewinding operation. If the progress bit is 1, it can be determined that the time is 1 minute or more and 2 minutes or less, respectively.
[0104]
Therefore, it is determined whether or not the progress bit is 1 (S166). In the case of 1, the battery voltage has been recovered since at least one minute has elapsed since the strobe was charged or the film was rewound, and the strobe charged bit or the predetermined amount of film rewound bit was reset to 0. At the same time, the elapsed bit is reset to 0 (S167). If the elapsed bit is 0, it is determined that the battery voltage has not yet recovered since 1 minute has not yet elapsed, and in order to wait for another 1 minute to elapse, the elapsed bit is set to 1 and interrupted. The process ends (S168).
[0105]
From the above procedure, when the strobe circuit performs a charging operation of a predetermined value or more, or when the film is rewound by a predetermined number or more, at least one minute after the start of each operation until a maximum of 2 minutes elapses. When the battery check reference voltage is lowered from the normal reference voltage according to each operation, the battery has sufficient remaining capacity for normal operation. The probability of prohibiting the operation can be reduced, and the operability can be improved.
[0106]
On the other hand, if the battery is really depleted, even if the reference voltage is temporarily reduced after energizing a large load, the battery voltage will decrease further. Informs that the remaining amount is very low, and if it is in a further lowered state, if more than 2 minutes have passed after energizing the heavy load, the operation prohibition state is determined based on the same reference value as the normal battery check and finally The reliability of the battery check will not be lost.
[0107]
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to the drawings.
FIG. 9 is a block diagram of a camera according to the third embodiment of the present invention.
FIG. 10 is a flowchart of the operation when the operation switch of the camera shown in FIG. 9 is operated.
FIG. 11 is a flowchart of the operation when the watch timer interrupt of the camera shown in FIG. 9 occurs.
[0108]
In FIG. 9, reference numeral 15 denotes a battery type detection means for determining the type of battery loaded in the camera. In addition, the same code | symbol is attached | subjected to the other structure same as FIG. 1, and the overlapping description is abbreviate | omitted.
[0109]
Here, first, the battery type detection means 15 determines the type of the battery loaded in the camera. Depending on the camera, either a commonly used lithium battery or an alkaline battery such as an AA battery can be used, a small battery installed inside a standard camera, or a large battery outside the camera. By connecting to the camera, there is a battery that can preferentially use an external battery. In this embodiment, it is assumed that the system can use an external battery.
[0110]
The description will be made assuming that the characteristics of the A / D converter are the same as those of the first embodiment, and that the first reference voltage of the battery check is the same as that of the first embodiment.
[0111]
Hereinafter, in this embodiment, attention is paid only to the charging operation of the strobe with the largest load among the operations of the camera, and when the charging operation of the strobe is executed, the information is stored and a certain time elapses after execution. Until the battery check reference voltage is changed to a reference voltage lower than the first reference voltage. When a small battery loaded in a standard camera is used by the battery type detection means, this reference voltage is converted to an A / D conversion conversion value rather than the first reference voltage as in the conventional example. If it is determined that an external large battery is used, the voltage drop is less than that of the internal small battery, and the A / D conversion value is less than the first reference voltage. The value is 8H smaller.
[0112]
On the other hand, as described in the first embodiment, the state of recovery of the battery voltage after supplying a large load varies greatly depending on the temperature of the battery.
[0113]
Therefore, in the present embodiment, when the strobe charging operation is executed, the battery check reference voltage is set to a reference voltage lower than the first reference voltage until a predetermined time elapses after the information is stored. Although this is changed, the environmental temperature is measured by the temperature detecting means 3 during this fixed time, and the temperature is switched according to the result.
[0114]
That is, if the temperature is room temperature or higher, it waits for 1 minute to 2 minutes, but if the temperature is low, this time is extended to 2 minutes to 3 minutes.
[0115]
If the battery check operation is performed again within a certain period of time after the completion of flash charging, the camera operation is permitted up to a battery voltage lower than the normal operation prohibition voltage. The comparison reference value is switched according to the type of battery.
[0116]
Next, the operation will be described with reference to the flowchart of FIG.
[0117]
In the camera sequence, for example, the operation after entering the strobe charging sequence by pressing the release switch or the like is the same as described in FIG.
[0118]
First, it waits for the operation switch to change (S170). At this time, the CPU 1 is set to accept an interrupt of a clock counter that is timed with a low-speed clock. In this state, a change occurs in the operation switch, and when the CPU 1 is activated, a predetermined operation is performed according to the operated switch.
[0119]
Determine the type of battery currently used by the camera. It is determined whether it is an internal small battery or an external large battery according to the output of the battery type detection means 15 (S171).
[0120]
Next, a battery check is performed. Here, in a state where a predetermined load is energized, the battery voltage is measured by the battery voltage detecting means 4 by A / D conversion (S172).
[0121]
Next, the A / D value is compared with a reference voltage to determine whether or not to prohibit the operation. Before that, information on the flash charged bit of the EEPROM 12 is read (S173).
[0122]
It is determined whether or not the result read from the EEPROM 12 is set to 1 (S174). If the voltage remains 0, the strobe is not charged immediately before the large load is supplied, so that the battery voltage is determined to be in a steady state and compared with the A / D conversion result of the battery voltage. As a reference voltage for this purpose, the first reference voltage 70H is used (S176).
[0123]
When it is set to 1, it is determined that the strobe has been charged immediately before and the battery voltage has temporarily decreased. Here, the battery type discrimination result is confirmed (S175). When the battery currently used is an internal battery, it is determined that the amount of voltage decrease is large, and 60H is obtained by subtracting 10H from the first reference voltage 70H as a reference voltage to be compared with the A / D conversion result of the battery voltage. Is set (S177).
[0124]
On the other hand, if it is determined that the battery currently in use is an external battery, it is determined that the amount of voltage decrease is not so large, and the reference voltage to be compared with the A / D conversion result of the battery voltage is the first voltage. The voltage is lowered from the reference voltage 70H and set to 68H (S178). Thus, the reference voltage set in S176, S177, and S178 is compared with the battery voltage that has been A / D converted previously (S179). When the reference voltage is 70H, the operation prohibition voltage is 2.19V, 2.03V for 68H, and 1.88V for 60H, as previously obtained.
[0125]
If the battery voltage is greater than any of the previously set reference voltages, it is determined that the camera is operable, and the camera sequence corresponding to the previously operated operation switch is executed (S180).
[0126]
If it is determined in S179 that the battery voltage does not reach any of the reference voltages, it is determined that the camera cannot function normally, and the information display means 5 displays that the operation is prohibited. , Return to the operation switch waiting loop of S170 (S181).
[0127]
Next, processing when an interrupt is generated by the previously set clock counter during this sequence will be described with reference to the flowchart of FIG.
[0128]
The camera of the present embodiment measures time by a low-speed oscillator and displays clock information on the information display means 5. For this reason, when the clock counter interrupts, the clock data stored in the RAM (not shown) and the elapsed time of the clock timer are added and written again in the RAM (S190).
[0129]
Next, it is determined whether or not the display means needs to be rewritten as a result of updating the clock data (S191). In general, the clock information displays the date and time, and the date and time, so in such a case, the clock display on the display means needs to be updated when the “minute” of the clock is increased. is there. Therefore, the display is updated (S192). Further, in the present embodiment, it is determined whether or not the display needs to be updated, that is, whether or not 1 is set to the flash charged bit of the EEPROM 12 every minute. That is, the flash charged bit of the EEPROM 12 is read (S193). It is determined whether or not the strobe charged bit is set to 1 (S194).
[0130]
If the flash-charged bit of the EEPROM 12 is not set to 1, since the history of charging the flash is not left, the interrupt process is finished without doing anything. On the other hand, when the strobe charged bit is set to 1, data in which the elapsed time since the strobe charged bit is detected is recorded at a predetermined address in the EEPROM (hereinafter referred to as elapsed data). Is read (S195).
[0131]
That is, if the elapsed data is 0, the strobe charged bit is set to 1 after the previous clock timer interruption, indicating that it is within 1 minute after the strobe charge. For example, it can be determined that it is 1 minute or more and 2 minutes or less after the flash charging, and if it is 2, it can be determined that it is 2 minutes or more and 3 minutes or less after the flash charging. In order to set the elapsed time, temperature is measured (S196).
[0132]
Therefore, the output of the temperature detection means 3 is A / D converted, and based on this information, it is determined whether the ambient temperature is above normal temperature or below. Here, it is determined whether the temperature is 0 ° C. or higher (S197).
[0133]
If it is determined that the temperature is 0 ° C. or less, it is determined whether the elapsed data is 2 (S198). If the elapsed data is 2, it means that at least 2 minutes have elapsed since the strobe was charged. Therefore, it is determined that the battery voltage has been sufficiently recovered even at 0 ° C. or lower. Is reset to 0 and the flash charged bit is reset to 0 (S202).
[0134]
If the elapsed data is not 2, the elapsed data is incremented and the next clock timer interrupt is waited (S201). Thus, if the strobe charged bit is set to 1 when the temperature is 0 ° C. or lower, the strobe charged bit is set to 1 for at least 2 minutes.
[0135]
If the temperature is 0 ° C. or higher in S197, it is determined whether the elapsed bit is 1 or higher (S199).
[0136]
In the case of 1 or more, since at least 1 minute has elapsed since the flash charging, if it is 0 ° C. or more, it is determined that the battery voltage has recovered, the flash charged bit is reset to 0, and the elapsed bit is set to 0 (S200).
[0137]
If the elapsed bit is 0, since 1 minute has not yet elapsed, it is determined that the battery voltage has not yet recovered, and in order to wait for another 1 minute to elapse, the elapsed bit is incremented and interrupted. The process ends (S201).
[0138]
In S199, when the external battery is used, counting is performed until the elapsed data becomes 2, and when switching to the internal battery, the determination of S199 may be made with the elapsed data remaining at 2. , “1” or more is determined. Then, if the strobe charged bit is set to 1 when the temperature is 0 ° C. or higher, the strobe charged bit is set to 1 for at least one minute.
[0139]
According to the third embodiment as described above, when the strobe circuit performs a charging operation of a predetermined value or more from the procedure as described above, when the temperature is high after the start of the charging operation, it is at least one minute at the longest. The battery check reference voltage is set to be lower than the normal reference voltage until 2 minutes elapse, at least 2 minutes if the temperature is low, and 3 minutes at the longest.
[0140]
Furthermore, the reference voltage at this time can be finely controlled by further lowering the internal small battery, and there is a sufficient remaining amount for normal operation. Therefore, the probability of prohibiting the operation only when it is lowered is reduced, and the operability can be further improved.
[0141]
(Other embodiments)
Up to this point, in order to simplify the explanation, only the reference voltage for the operation inhibition voltage has been described, but it is needless to say that the same method can be applied to the operation warning voltage.
[0142]
In the present invention, the flash charged bit, the predetermined film rewind bit, and the progress bit are stored in the EEPROM 12, but the storage area inside the CPU 1 may be used. Even if a volatile memory that is not backed up by a battery is considered to lose information only when the battery is replaced, it is sufficient for the application of the present invention.
[0143]
Further, in the present invention, the time measurement is also used as the clock timing means of the camera for the simplification of the software. Of course, more accurate measurement is possible by measuring the elapsed time after execution of the predetermined operation accurately. Needless to say, control becomes possible.
[0144]
In the present invention, the reference value is changed depending on whether the charging voltage before the start of the strobe charging is equal to or higher than the predetermined value. However, the charging voltage before the charging start and the change amount of the predetermined value are controlled linearly. Of course, finer control becomes possible.
[0145]
In the present invention, the reference voltage is changed only for the strobe charging and the film rewinding operation. However, the reference voltage is similarly applied to other operations with a large load (for example, cueing of unexposed frames). It goes without saying that appropriate control is performed by changing the voltage according to the magnitude of each load.
[0146]
Further, in the present invention, the comparison reference voltage is changed according to the temperature measurement data, and the change time of the reference voltage is changed according to the detection result of the battery type. May be changed.
[0147]
In addition, it is possible to change the comparison reference voltage and the change time according to other measurement data, for example, the A / D conversion result of the battery voltage when the strobe charged bit is 0. In other words, when the strobe completion bit is 0, the battery voltage A / D result when the battery is fully recovered is used to judge how much the battery is depleted, and if the battery is depleted, the corresponding amount is compared. Reduce the reference voltage. Alternatively, it is possible to control to increase the change time.
[0148]
【The invention's effect】
As described above, according to the first aspect of the present invention, the battery check is performed by switching the output of the reference voltage setting unit only for the time set by the time setting unit in accordance with the storage contents of the storage unit. In addition, the reliability of the warning display can be improved, and a camera with excellent operability in consideration of battery characteristics can be provided.
[0149]
Further, according to the invention described in claim 2, since one of the plurality of modes is the strobe charging operation, the reliability of the battery check and warning display after the strobe charging operation is improved, and the characteristics of the battery are taken into consideration. Can provide a camera with excellent operability.
[0150]
Furthermore, according to the third aspect of the present invention, the reliability of the battery check and the warning display can be improved without being affected by the temperature by changing the output of the reference voltage setting means or the time setting means according to the temperature. In addition, it is possible to provide a camera with excellent operability in consideration of battery characteristics.
[0151]
According to the fourth aspect of the present invention, the outputs of the reference voltage setting means and the time setting means are made variable according to the output of the battery voltage detection means, so that the battery check and It is possible to improve the reliability of the warning display and provide a camera with excellent operability in consideration of battery characteristics.
[0152]
Further, according to the invention described in claim 5 or 7, by making the outputs of the reference voltage setting means and the time setting means variable according to the type of the battery, the battery check and It is possible to provide a camera with excellent operability in consideration of battery characteristics by improving the reliability of warning display.
[0153]
According to the sixth aspect of the present invention, the strobe charge bit, the film predetermined amount winding bit, and the elapsed bit are stored in the RAM as information relating to the operation mode, so that the outputs of the reference voltage setting means and the time setting means are switched. Accurate data can be stored.
[0154]
Furthermore, according to the invention described in claim 8, it is possible to perform a battery check and an accurate warning display according to the state of the battery.
[0155]
Furthermore, according to the ninth aspect of the invention, an accurate battery check and warning display are possible.
[0156]
Furthermore, according to the invention described in claim 10, the reference voltage can be set to one.
[Brief description of the drawings]
FIG. 1 is a block diagram of a camera according to a first embodiment of the present invention.
FIG. 2 is a diagram showing fluctuations in battery voltage of the camera shown in FIG. 1;
FIG. 3 is a flowchart of an operation at the time of strobe charging of the camera shown in FIG. 1;
4 is a flowchart of an operation when an operation switch of the camera shown in FIG. 1 is pressed.
FIG. 5 is a flowchart of an operation when an interrupt of a watch timer of the camera shown in FIG. 1 occurs.
FIG. 6 is a flowchart of a film rewinding operation of the camera according to the second embodiment of the present invention.
7 is a flowchart of an operation when an operation switch of the camera shown in FIG. 6 is pressed.
8 is a flowchart of an operation when an interrupt of a clock timer of the camera shown in FIG. 6 occurs.
FIG. 9 is a block diagram of a camera according to a third embodiment of the present invention.
10 is a flowchart of an operation when an operation switch of the camera shown in FIG. 9 is operated.
11 is a flowchart of an operation when an interrupt of a clock timer of the camera shown in FIG. 9 occurs.
[Explanation of symbols]
1 CPU
2 A / D converter
3 Temperature detection means
4 Battery voltage detection means
5 Information display means
6 High-speed oscillator
7 Low-speed oscillator
8 Strobe circuit
9 Motor
10 Film feeding means
11 Exposure control means
12 EEPROM
13 Switch detection means
14 DC / DC converter
15 Battery type detection means

Claims (10)

A plurality of loads to which power is supplied from the battery, a plurality of operation modes in which predetermined energization is performed for each load, a battery voltage detecting means for detecting the voltage of the battery, a first reference voltage value, and Reference voltage setting means capable of setting a lower reference voltage value, comparison means for comparing the detected battery voltage with the output of the reference voltage setting means, and information relating to the operation mode of the camera executed immediately before is stored. Storage means, time measuring means for measuring the elapsed time since execution of the previous camera operation mode, and time setting means for setting the time to be measured by the time measuring means, according to the output of the comparison means In the camera for prohibiting or warning the operation, the output of the reference voltage setting means is switched only for the time set by the time setting means in accordance with the stored contents of the storage means. La. 2. The camera according to claim 1, wherein one of the plurality of operation modes is a strobe charging operation. 3. The camera according to claim 1, wherein the output of the reference voltage setting means or the output of the time setting means is variable according to temperature. 3. The camera according to claim 1, wherein the output of the reference voltage setting means or the output of the time setting means is variable according to the output of the battery voltage detection means. 3. The camera according to claim 1, wherein the output of the reference voltage setting means or the output of the time setting means is variable according to the type of battery. The information regarding the operation mode of the camera immediately before storing in the storage means is a strobe charged bit indicating strobe charging, a predetermined amount of film rewinding bit indicating film rewinding, and a progress bit indicating elapsed time. The camera according to claim 1. 6. The camera according to claim 5, wherein the battery type is a battery type detecting means for detecting whether the battery is an internal battery or an external battery. In an electronic device having a load supplied with power from a battery, voltage detection means for detecting the voltage of the battery, and determination means for determining a battery state by comparing the detected voltage with a first reference voltage The reference voltage is set to a second reference voltage lower than the first voltage within a predetermined time after driving the load. 9. The electronic apparatus according to claim 8, wherein the reference voltage is set to a voltage higher than the second reference voltage after a predetermined time has elapsed. 10. The electronic device according to claim 8, wherein the reference voltage is prohibited from being set to the second reference voltage when the drive amount of the load is smaller than a predetermined amount according to the drive amount of the load. machine.

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