JP2004085591A - camera - Google Patents

Abstract

An object of the present invention is to provide a camera that does not judge that a battery is exhausted due to internal resistance when a new environmentally friendly battery containing no mercury is loaded.
When a battery check circuit determines that the remaining amount of a battery is insufficient, a camera control circuit operates a strobe charging circuit of a strobe circuit at least once for a predetermined time, and thereafter, Has a battery check program for performing a battery check operation again.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a camera that performs a battery check operation that prevents a battery end from being determined regardless of a new battery when an environmentally friendly battery that does not contain mercury has a large internal resistance.
[0002]
[Prior art]
Conventionally, a battery check method in a camera involves connecting a real load such as a stepping motor or a dummy load such as a resistance element to a battery for a short time, extracting a relatively large current from the battery, and comparing the battery voltage at that time with a predetermined voltage. By doing so, it is general to determine whether the battery level is sufficient.
[0003]
That is, the discharge characteristic (lifetime characteristic) of an alkaline manganese battery used for a camera is generally that the voltage gradually decreases as the battery is used, while the internal resistance increases. In the case of a new battery, there is a phenomenon that the internal resistance is relatively large in the initial stage of use.
[0004]
In particular, since this phenomenon is remarkable in an environment-friendly alkaline manganese battery containing no mercury, the initial internal resistance may be larger than the internal resistance at the actual life stage. When such a battery is checked by the above-described method, it is determined that the battery is the end of the battery even though it is a new battery.
[0005]
To solve such problems, Japanese Patent Application Laid-Open Nos. Hei 6-281710 (Japanese Patent Application No. 5-90517), Japanese Patent Application Laid-Open No. Hei 7-64146 (Japanese Patent Application No. 5-209553), and Japanese Patent Application Laid-Open No. Hei 7-181548 (Japanese Patent Application No. Hei 5-181). Inventions such as Japanese Patent Application Laid-Open No. Hei 8-184475 (Japanese Patent Application No. 5-337639) and Japanese Patent Application Laid-Open No. Hei 8-218135 (Japanese Patent Application No. 7-18277) are disclosed.
[0006]
First, in Japanese Patent Application Laid-Open No. 6-281710, the battery activation means is energized before the battery check operation. In this method, the battery is activated every time the battery check is performed.
[0007]
In Japanese Patent Application Laid-Open No. 7-64146 (Japanese Patent Application No. 5-209553), when a battery is checked by energizing a dummy load, a period during which the voltage immediately drops immediately after energizing the load (a period during which the internal resistance is large). ) Is avoided, and the judgment is made based on the voltage when the voltage becomes substantially flat after a sufficient time has passed. In this case, the time required for the battery check in the camera is required to be within about 100 msec in consideration of the time lag until the shutter.
[0008]
Japanese Patent Application Laid-Open No. 7-181548 (Japanese Patent Application No. 5-325426) discloses that a voltage is measured a plurality of times while a load is energized, and at least a voltage immediately after the energization and a voltage after a lapse of time are measured. By determining the difference, it is determined whether the obtained voltage data is based on the initial characteristics of the battery containing no mercury or the characteristics over the battery life.
[0009]
Further, Japanese Patent Application Laid-Open No. Hei 8-184752 (Japanese Patent Application No. 5-337639) discloses that a battery having an active AF function (ranging function) measures a battery voltage during a light emitting operation. It is limited to cameras.
[0010]
Also, in Japanese Patent Application Laid-Open No. Hei 8-21135 (Japanese Patent Application No. 7-18277), a load for battery check is supplied to a red-eye prevention lamp or the like for a short time (time during which the lamp does not shine). The comparison of the battery voltage with the reference voltage is repeated. At this time, the voltage measured at the time of the first energization is compared with a relatively low reference voltage, and in the subsequent repetition, the voltage is compared with a relatively high reference voltage, and the remaining battery level is determined based on the comparison result. .
[0011]
[Problems to be solved by the invention]
However, in Japanese Patent Application Laid-Open No. 6-281710, there is a problem that the battery is activated even in a battery that does not require activation, so that not only power is wasted but also a time lag until the shutter operation is large. .
[0012]
In Japanese Patent Application Laid-Open No. 7-64146, an alkaline manganese battery containing no mercury is energized to the dummy load. For example, when the energization is stopped for about 100 msec, the voltage immediately before the energization is stopped is substantially flat. Even if there is a battery, the voltage is almost the same as the voltage when the battery is actually consumed (the voltage at the time of the battery life), and it is not a sufficient countermeasure in consideration of the variation of the battery. On the other hand, setting the energization time to the dummy load to 1 second has a significant effect on the sequence of the camera, and it takes a long time to operate the camera, which is not practical.
[0013]
The method disclosed in JP-A-7-181548 collects, calculates, and compares a plurality of voltage data. For example, an A / D converter or a plurality of comparators and reference voltages are required. However, there is a disadvantage that the cost of a camera in a popular price range is significantly increased.
[0014]
The method disclosed in Japanese Patent Application Laid-Open No. H8-111135 is limited to a camera having an appropriate load, such as a lamp, and requires a plurality of reference voltages for comparing voltages. The disadvantage of this camera is that the cost is greatly increased.
[0015]
The present invention has been made in view of such a problem of the conventional camera, and an object of the present invention is to provide a camera that does not determine that the battery is exhausted even when a new battery is loaded. And
[0016]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the camera of the present application, when the battery check unit checks the remaining amount of the battery, when it is determined that the remaining amount of the battery is insufficient, it is necessary to charge the strobe at least once. Is performed to activate the battery, and thereafter, the battery operation is performed again.
[0017]
That is, in the camera according to claim 1 of the present application, the battery check means for determining whether the remaining amount of the battery is sufficient performs the battery check operation for the determination, and as a result, the remaining amount of the battery is insufficient. When it is determined that there is, the battery check unit charges the strobe at least once, and thereafter performs the battery check operation again.
[0018]
According to a second aspect of the present invention, in the camera according to the first aspect, the battery check unit performs the battery check operation when a main switch of the camera is turned on.
[0019]
In the camera according to claim 3 of the present application, in the camera according to claim 1, the control means of the camera has a low power consumption mode and a photographable mode, and the control means switches the low power consumption mode to the photographable mode. When switched, the battery check means performs the battery check operation.
[0020]
According to a fourth aspect of the present invention, in the camera according to the first aspect, when a battery is inserted and a power-on reset is applied to a control unit of the camera, the battery check unit performs the battery check operation. And
[0021]
In the camera according to the fifth aspect of the present invention, when the main switch of the camera is turned on, the control means of the camera charges the camera regardless of the charging state of the main capacitor of the strobe charging circuit. Is performed.
[0022]
The camera according to claim 6 of the present application is the camera according to claim 1, wherein the control means of the camera has a low power consumption mode and a photographable mode, and the photographable mode is activated from the low power mode. Preferably, the control means performs charging regardless of the state of charge of the main capacitor of the flash charging circuit.
[0023]
In the camera according to the present invention, when the battery is loaded in the camera and a power-on reset is applied to the control means of the camera, the control means controls the main capacitor of the strobe charging circuit. It is characterized in that charging is performed regardless of the charging state.
[0024]
The camera according to claim 8 of the present application has means for detecting the state of charge of the main capacitor for strobe charging, and battery checking means for determining whether or not the remaining amount of the battery is sufficient by a battery check operation, When the battery check means determines that the remaining amount of the battery is insufficient by the battery check operation, the battery check means performs charging at least once for a time corresponding to the state of charge of the main capacitor, and then again A battery check operation is performed.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a camera according to an embodiment of the present application will be described with reference to the drawings. FIG. 2 is a block diagram of a camera according to an embodiment of a portion related to the present invention.
[0026]
Reference numeral 1 denotes a control circuit as a part of control means for controlling the operation of the camera. The control circuit 1 includes a microcomputer, an interface circuit, and other peripheral circuits. A program for controlling almost all operations of the camera, such as a winding operation, and parameters such as initial values and reference values for operations and data for operations are stored.
[0027]
The camera has a battery check circuit 3 that determines whether the remaining battery level is sufficient by comparing a voltage VBC related to a voltage VB (battery voltage) of the battery 2 with a predetermined reference voltage Vref. I have.
[0028]
The battery check means in the claims of the present application includes a battery check circuit 3, a control circuit 1, and a battery check program stored in the control circuit 1. The microcomputer of the control circuit 1 stores a program for controlling the overall operation of the camera, a battery check program, and other control programs.
[0029]
The battery check program performs a battery check operation by the battery check circuit 3 to determine whether or not the remaining amount of the battery 2 is insufficient. If the battery check operation determines that the remaining battery amount is insufficient, The strobe charging circuit of the strobe circuit 4 is operated at least once for a predetermined time, and then the battery check operation is performed again.
[0030]
A power supply terminal Vcc of the microcomputer of the control circuit 1 is connected to the battery 2 via the diode 5 and is supplied with power from the battery 2. The Reset terminal of the microcomputer is connected to the battery 2 via the resistor 6, and the microcomputer of the control circuit 1 is supplied with power from the battery 2 and reset when the battery 2 is loaded in the camera.
[0031]
A strobe circuit 4 and a battery check circuit 3 are connected to a positive electrode of the battery 2, and a strobe circuit 4 and a battery check circuit 3 are connected to an input / output port of a microcomputer of the control circuit 1.
[0032]
The strobe circuit 4 is of a known type that emits light by discharging the electric charge charged in the main capacitor through the Xe tube. The strobe circuit 4 includes a strobe charging circuit that charges the main capacitor with the battery 2 based on a control command from the microcomputer of the control circuit 1 and a Xe tube (xenon tube) that discharges the main capacitor according to the control command of the microcomputer. It has a strobe light emitting circuit that emits light, and a charging voltage detection circuit (means for detecting the state of charge of the main capacitor) that detects the state of charge of the main capacitor of the strobe charging circuit and sends it to the microcomputer of the control circuit 1.
[0033]
The battery check circuit 3 includes transistors Q1, Q2, resistors R1, R2, R3, and a comparator CMP. The emitters of the transistors Q1, Q2 are connected to the positive electrode of the battery 2, and the bases of the transistors Q1, Q2 are connected to a control circuit. The microcomputer is connected to the BCC terminal and the BCL terminal set as the battery check input / output port of the microcomputer.
[0034]
The collector of the transistor Q1 is grounded via a resistor R1 as a dummy load. The resistor R1 is a resistor connected to the battery at the time of battery check, and is switched by the transistor Q1.
[0035]
The collector of the transistor Q2 is grounded via the resistors R2 and R3. The series circuit of the resistors R2 and R3 is connected to the positive electrode of the battery 2 via the transistor Q2 so as to be switched by the transistor Q2. The portion where the battery voltage VB is divided by the resistors R2 and R3 is connected to the inverting input terminal of the comparator CMP. The comparator CMP is supplied with power from the power supply terminal VCC. The reference voltage Vref output from the constant voltage circuit 6 is input to the non-inverting input terminal of the comparator CMP, and the divided voltage VBC of the resistors R2 and R3 is compared with the reference voltage Vref. The comparator CMP and the constant voltage circuit that generates the reference voltage Vref are integrated into an IC. The output of the comparator CMP is connected to the microcomputer of the control circuit 1.
[0036]
The transistors Q1 and Q2 perform the switching operation when the terminal voltages of the BCC terminal and the BCL terminal of the control circuit 1 become L level, and when the voltage VBC of the voltage dividing part of the resistors R2 and R3 is higher than the reference voltage Vref, The comparator CMP outputs an L-level signal to a battery check BCIN terminal of the microcomputer of the control circuit 1. The comparator CMP outputs an H-level signal to the battery check BCIN terminal of the microcomputer of the control circuit 1 when the voltage VBC at the voltage dividing portion of the resistors R2 and R3 is lower than the reference voltage Vref.
[0037]
The program for checking the battery of the microcomputer of the control circuit 1 is to charge the strobe circuit 4 when the terminal voltage of the BCIN is at the H level because the internal resistance of the new battery is high. Is controlled to be activated. This will be described later.
[0038]
A switch input circuit is connected to the input / output port of the microcomputer of the control circuit 1. In addition to operation switches such as a main switch and a release switch of the camera, a state detection switch for detecting a mechanical state of the camera such as a back cover switch is also connected to the switch input circuit.
[0039]
FIG. 4 shows a part of a conventional battery check operation, and FIGS. 5 and 6 show voltage waveforms of respective parts of the battery check circuit 3 and timings of respective signals during the battery check operation shown in FIG.
[0040]
In the battery check operation of FIG. 4, first, the previous battery check flag (BC flag) is reset (step 11). Next, the BCC terminal of the microcomputer of the control circuit 1 is set to the L level to turn on the transistor Q2 (step 12). As a result, the series circuit of the resistors R2 and R3 is energized, and a voltage VBC proportional to the battery voltage VB is generated in the voltage dividing portion of the resistors R2 and R3 (see FIGS. 5 and 6).
[0041]
Next, when the BCL terminal of the microcomputer of the control circuit 1 is set to L level, the transistor Q1 is turned on (step 13), and a current flows from the battery 2 to the dummy load resistor R1. This state is continued for 20 msec (step 14). The battery voltage VB when the dummy load resistor R1 is energized is, for example, assuming that the internal resistance of the battery is 0.5Ω and the current flowing through the dummy load resistor R1 is 1A, the battery voltage VB is the voltage immediately before the dummy load resistor R1 is energized. Since the voltage drops by 0.5 V, the voltage VBC proportional to the battery voltage VB also has the same waveform (see FIGS. 5 and 6).
[0042]
This voltage VBC is compared with reference voltage Vref. When the voltage VBC> Vref, an L level is output to the output of the comparator CMP, and when the voltage VBC <Vref, an H level is output. This output voltage is input to the BCIN terminal of the microcomputer of the control circuit 1.
[0043]
When approximately 20 msec has elapsed after the dummy load resistor R1 is energized, the battery check program of the control circuit 1 sets a battery check flag (BC flag = 1) when BCIN = H level (step 16). Thereafter, the BCL terminal and the BCC terminal are set to the H level (steps 17 and 18), the battery check operation is completed, and the process returns to the main routine.
[0044]
When BCIN = L (battery OK) in step 15, the process proceeds to step 17, the BCL terminal and the BCC terminal are set to the H level, the battery check operation is completed, and the process returns to the main routine.
[0045]
In the main routine, if the battery check flag is not set (when BCF = 0), normal camera operation is permitted. If the BC flag is set (BCF = 1), a battery end is displayed, Operations such as exposure and film winding are prohibited.
[0046]
FIG. 6 shows a battery voltage waveform at the time of a battery check when a conventional dry battery containing a small amount of mercury is used. When the dry battery of FIG. 6 is loaded into the camera of FIG. 1 and the BCC terminal is set to L level, the voltage VBC1 at the voltage dividing portion of the resistors R2 and R3 rises and becomes higher than the reference voltage Vref, and the BCIN terminal becomes L level. Next, when the BCL terminal is set to the L level for 20 msec and the BCL terminal is set to the H level after 20 msec, the voltage VBC1 at the voltage dividing point becomes flat after decreasing, the voltage VBC increases after 20 msec, and the BCIN terminal is set to the H level. become. When the battery level becomes low and the voltage VBC2 becomes lower than the reference voltage Vref, an H-level output voltage is input from the comparator CMP to the BCIN terminal. Since the battery having the waveform shown in FIG. 6 maintains a flat waveform when a load is applied, the voltage level output to the BCIN terminal is also stable.
[0047]
At present, however, environmentally friendly batteries that do not contain mercury are commercially available in order to respond to environmental conservation. This mercury-free battery may have a high initial internal resistance because it is not activated. FIG. 5 shows the change in the voltage VBC of the battery containing no mercury.
[0048]
When the battery 2 (see FIG. 2) of the camera is a battery containing no mercury and is a new battery but has a large internal resistance, as shown in FIG. There is a region where the voltage drops sharply immediately after energization, and thereafter, the characteristics are almost flat. The time during which the voltage is largely dropped is about 10 msec or less, although it depends on the magnitude of the current flowing through the resistor R1, which is a dummy load. Therefore, if a battery check is performed within about 10 msec immediately after energization, it is determined that the battery is exhausted even though it is a new unused battery.
[0049]
Therefore, it is conceivable to perform a battery check in an area with flat characteristics to avoid this area where the voltage is greatly reduced. The fact is close to the voltage. For example, in a 3V camera (eg, two AA batteries), the voltage at the battery end varies depending on the load current when performing a battery check, but is usually 2 to 2.2V.
[0050]
That is, with reference to FIG. 5, when the voltage VBC proportional to the battery voltage VB is a high voltage VBC1 (solid line), VBC1> Vref, so the battery voltage is OK, but the low voltage VBC2 (dashed-dotted line) In the case of ()), since VBC2 <Vref, the battery voltage becomes insufficient, and the battery is not always OK.
[0051]
In this example, the time during which the dummy load resistor R1 is energized is 20 msec. However, this waveform does not basically change even if the current is applied for several hundred msec. Activation inside the battery is not enough.
[0052]
In order to sufficiently activate the inside of the battery, the battery check program according to the embodiment of the present invention performs the following operation. In this battery check operation, as an example, the battery check program is set to operate when a main switch (not shown) connected to the microcomputer of the control circuit 1 is turned on. It is not limited to this.
[0053]
FIG. 1 shows the flow of the above-described battery check program. FIG. 3 shows a waveform of the battery voltage VB when the battery check operation shown in the flowchart of FIG. 1 is performed on a battery that is a new battery but has a large internal resistance, such as a battery that does not contain mercury. .
[0054]
Steps 51 to 54 in the flowchart of FIG. 1 are the same as steps 11 to 14 of FIG. 4 and have already been described, and thus the description thereof will be referred to.
[0055]
If it is determined in step 55 that BCIN = L (the battery voltage is sufficient because the BCIN terminal is at the L level), the process proceeds to step 66, the BCL terminal and the BCC terminal are set to the H level, the battery check operation is completed, and the process returns to the main routine.
[0056]
In step 55, when the BCIN terminal is at the H level (BCIN = H: the battery voltage is insufficient), the BCL terminal and the BCC terminal are set to the H level (steps 56 and 57), and the energization to the dummy load resistor R1 is performed once. Then, as shown in FIG. 3, the flash is charged for 100 msec after a predetermined time t1 msec (step 59).
[0057]
After a predetermined time t2 msec after the charging of the strobe is completed, the BCC terminal and the BCL terminal are set to the L level again to energize the dummy load resistor R1 (steps 61 and 62), and about 20 msec after the energization, the microcomputer of the control circuit 1 Check the voltage level of the BCIN terminal.
[0058]
In step 64, if the BCIN terminal is at the L level (BCIN = L: the battery voltage is sufficient), the process proceeds to step 66, where the BCL terminal and the BCC terminal are set to the H level to end the battery check operation and return to the main routine.
[0059]
If the BCIN terminal is at the H level (BCIN = H: battery voltage is insufficient) in step 64, a BC flag (battery check flag) is set (BCF = 1) (step 65). According to the BC flag set (BCF = 1), it is determined that the remaining battery level is low as a result of the battery check, and a display indicating "battery end" is displayed on a liquid crystal display or the like of the camera. , Prohibit camera operation. BCF = 0 remains in the case of the battery OK. After setting BCF = 1, the BCL terminal and the BCC terminal are set to the H level (steps 66 and 67) to end the battery check operation and return to the main routine.
[0060]
In the case of a battery whose battery capacity has actually been consumed and has reached the end of its life, if the voltage is lower than the determination level in the first battery check, it is usually lower than the determination level in the second battery check. Battery end is determined.
[0061]
In the above embodiment, the time t1 between the first battery check and the start of the strobe charge and the time t2 from the end of the strobe charge to the second battery check are several msec to the extent that the release sequence of the camera is not delayed. What is necessary is just to determine suitably within several tens msec. Further, in this embodiment, the energizing time to the strobe charging circuit is set to 100 msec. However, taking into consideration the main capacitor capacity of the strobe of the target camera, the characteristics of the charging circuit used, the variation of the battery, and the like. Decide.
[0062]
According to the battery check means of the camera of the above-described embodiment, as shown in FIG. 3, in the first battery check due to the energization of the dummy load resistor R1, the voltage VBC of the divided voltage of the resistors R2 and R3 is used. May be lower than the reference voltage Vref, the battery is activated by the strobe charging, and thus becomes higher than the reference voltage Vref in the second battery check.
[0063]
That is, when it is determined that the remaining amount of the battery is insufficient, the strobe charging circuit of the strobe circuit 4 is charged at least once, and then the battery check is performed again. Even if a new and unused battery with a high internal resistance is loaded into the camera, it is possible to prevent problems such as a battery end being determined immediately after a new battery is loaded and the camera not operating. .
[0064]
If it is determined in the first battery check operation that activation of the battery is not necessary, the strobe circuit 4 is not charged, and the strobe is charged every time the battery check operation is performed (battery activation). This eliminates the problem that power is wasted and the time lag from when the release button is pressed to when the shutter is released is increased, so that the user loses a photo opportunity.
[0065]
Furthermore, the merit of this method is that the strobe charging is used as a method of activating the battery without adding any new parts, so that the battery is sufficiently activated and the circuit scale is small, so that the price in the popular price range is low. The camera is advantageous for cost reduction, and can be applied to almost all cameras having control means such as a microcomputer and a strobe. The energy charged in the strobe circuit 4 is part of the energy when the strobe is fired by the actual exposure operation, so that it is not wasted.
[0066]
The above-described battery check operation is set so that the battery check operation is performed when the main switch of the camera is turned on. However, it is needless to say that the battery check operation is not limited to the case where the main switch of the camera is turned on.
[0067]
For example, the microcomputer of the control circuit 1 performs the above-described battery check operation when the microcomputer of the control circuit 1 is activated from a low power consumption mode in which a clock oscillation circuit or the like is not operated to a photographable state by operating a switch or turning on a sensor. It may be.
[0068]
In this way, when the battery check operation is performed unconditionally when the main switch is turned on, even if it is determined that the remaining battery level is insufficient due to the insertion of a new battery having a high internal resistance into the camera for the first time, the strobe is not used. Since the new battery is activated in a short time by charging, the probability that the camera will not operate due to the battery NG during the release sequence from when the release button is pressed to when the shutter is released can be reduced.
[0069]
In the above-described battery check operation, the battery check operation may be performed unconditionally when a battery is inserted into the camera and a power-on reset is applied to the control unit.
[0070]
With this configuration, the probability that the first battery check after the replacement with a new battery having a high internal resistance becomes the battery NG during the release sequence after the release button is pressed can be reduced.
[0071]
Alternatively, the battery check operation may be performed unconditionally when the control means including a microcomputer or the like is activated from a so-called low power consumption mode in which the clock oscillation circuit or the like is not operated to a photographable state by operating a switch.
[0072]
When the main switch of the camera (not shown) is turned on, charging may be performed for a predetermined time regardless of the state of charge of the main capacitor of the strobe circuit 4, and then the battery check operation of FIG. 1 may be performed. .
[0073]
In connection with the charging of the main capacitor of the strobe circuit 4, when the switch is operated from the above-described low power consumption mode to a photographable state, a predetermined value is obtained regardless of the charged state of the main capacitor of the strobe circuit 4. The battery check operation of FIG. 1 may be performed by performing time charging.
[0074]
As described above, when the main switch is turned ON or when the camera is started from the low power consumption mode to the shooting enabled state, charging is performed for a predetermined time regardless of the charging state of the main capacitor of the strobe. Since the battery has been activated several times by charging, even if a battery check is performed during the release sequence, the probability of occurrence of a time lag of the release due to flash charging can be reduced.
[0075]
Furthermore, when a battery is inserted into the camera and a power-on reset is applied to the microcomputer of the control circuit 1, charging may be performed for a predetermined time regardless of the charging state of the main capacitor of the strobe circuit 4.
[0076]
As described above, when a new battery having a high internal resistance is loaded into the camera and the microcomputer is subjected to power-on reset, charging is performed for a predetermined time regardless of the charging state of the main capacitor of the strobe. As a result, the battery is activated, so that even if the subsequent first battery check is performed during the release sequence, the probability that a time lag in the release sequence due to strobe charging occurs can be reduced.
[0077]
【The invention's effect】
According to the camera of the present invention, when it is determined that the remaining amount of the battery is insufficient, the strobe charging circuit of the strobe is charged at least once, and then the battery check is performed again. Even if a new and unused battery with high internal resistance is loaded into the camera, such as a compatible battery, the battery may be judged to be out of battery even after the new battery is loaded, or the camera may not operate. Failure can be prevented.
[Brief description of the drawings]
FIG. 1 is a flowchart of a battery check operation of a camera according to an embodiment of the present invention.
FIG. 2 is a block circuit diagram of a camera that performs a battery check operation of FIG. 1;
FIG. 3 is a waveform diagram of a battery voltage VBC that changes according to the battery check operation of FIG. 1;
FIG. 4 is a flowchart of a conventional battery check operation in the camera having the block circuit of FIG. 2;
FIG. 5 is a waveform diagram when the conventional battery check operation of FIG. 4 is performed in an environment-friendly battery not using mercury.
FIG. 6 is a waveform diagram when the conventional battery check operation of FIG. 4 is performed on a conventional dry battery containing mercury.
[Explanation of symbols]
1 control circuit (control means)
2 Battery
3 Battery check circuit
4 Strobe circuit

Claims (8)

When the battery check means for determining whether the remaining amount of the battery is sufficient performs the battery check operation for the determination, when it is determined that the remaining amount of the battery is insufficient, the battery check means The camera charges the strobe at least once, and then performs a battery check operation again. 2. The camera according to claim 1, wherein said battery check means performs said battery check operation when a main switch of the camera is turned on. 2. The camera according to claim 1, wherein the control means of the camera has a low power consumption mode and a photographable mode, and the battery check is performed when the control means is switched from the low power consumption mode to the photographable mode. A camera, wherein the means performs the battery check operation. 2. The camera according to claim 1, wherein the battery check unit performs the battery check operation when a battery is inserted and a power ON reset is applied to the control unit of the camera. 2. The camera according to claim 1, wherein when a main switch of the camera is turned on, a control unit of the camera performs charging regardless of a charging state of a main capacitor of the strobe charging circuit. 2. The camera according to claim 1, wherein the control unit of the camera has a low power consumption mode and a photographable mode, and when the photographable mode is started from the low power consumption mode, the control unit controls the strobe charging. A camera that performs charging regardless of the state of charge of a main capacitor of a circuit. 2. The camera according to claim 1, wherein when a battery is loaded in the camera and a power-on reset is applied to the control means of the camera, the control means performs charging regardless of a charging state of a main capacitor of the strobe charging circuit. A camera characterized by performing. Means for detecting the state of charge of the main capacitor for strobe charging, and battery checking means for determining whether or not the remaining amount of the battery is sufficient by a battery check operation, wherein the battery check means performs the battery check operation. When it is determined that the remaining amount of the battery is insufficient, the battery check unit performs charging at least once for a time corresponding to the state of charge of the main capacitor, and then performs the battery check operation again. Camera.

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