JPH11109452A - camera - Google Patents

Abstract

(57) [Summary] [Problem] To prevent a change in battery characteristics due to temperature fluctuation, promote heat generation of the battery itself, promote battery activation,
Improves battery characteristics at low temperatures. SOLUTION: A CPU 1 for controlling a camera, an ambient temperature measuring means 5 for measuring an ambient temperature of the camera, and a CPU 1
Strobe means 3 for emitting light in accordance with the control of the above, photometric means 4 for measuring the brightness of the subject, film information detecting means 6 for detecting sensitivity information of the photographic film, output of the photometric means 4, In a camera having automatic light emission setting means for determining whether or not to emit a strobe light in accordance with an output, intrinsic data of a photographing optical system, and the like, light emission of the automatic light emission setting means in response to an output of the ambient temperature measuring means 5 Change the reference level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera provided with a strobe device.

[0002]

2. Description of the Related Art In recent years, as cameras have become smaller, corresponding batteries have also become smaller. As the size of the battery is reduced, the battery capacity is reduced, the internal resistance is increased, and the output characteristics are particularly deteriorated when the temperature is lowered. Therefore, when a small battery is used, there is a tendency that the number of films fed is greatly reduced.

[0003] Since the price of a small battery is not proportional to the capacity, the price is not proportional to the capacity. Therefore, for the user, it is very expensive and unsatisfactory even though the price of the camera is small. there were.

[0004] In particular, due to the deterioration of the low-temperature characteristic, in a place where the outside air temperature is low, the operation of the camera is prohibited by a battery check as soon as a very small number of images are taken. When the battery is returned to room temperature, it may be possible to use it.

In order to solve such a problem, for example, Japanese Utility Model Laid-Open No. 58-131567 or Japanese Patent Publication No. Hei 8-1
As disclosed in, for example, Japanese Patent No. 6764, a technique for imparting temperature dependency to a battery check voltage has been disclosed. That is, the battery capacity cannot be used at low temperatures due to the deterioration of the low temperature characteristics of the battery.

Therefore, there arises a problem that batteries which can be used at normal temperature must be replaced with new batteries at low temperature.

[0007]

However, as the miniaturization of batteries progresses, the characteristics of batteries at low temperatures are different between after leaving the battery unused for a while and immediately after charging the strobe, for example. There has been a decline that is so different.

This is because once a large load current is supplied,
The temperature of the battery itself rises due to the heat generated by the battery itself, and the activation of the battery progresses, improving the characteristics of the battery. On the other hand, when the battery itself is in a low temperature state, the internal resistance increases and the battery when the load current is supplied This is because the voltage drop is further increased.

That is, as the internal resistance of the battery increases, the characteristics at a low temperature are greatly changed by the load supply history immediately before the battery itself.

When photographing is continuously performed at a low temperature, energy consumption is supposed to be higher than when the strobe is not fired. A phenomenon may occur.

Such a change in characteristics is so large that the conventional battery check voltage cannot be dealt with simply by giving the temperature dependency to the conventional battery check voltage, and this difference may cause a case where the capacity of the battery cannot be used effectively. doing.

An object of the first invention of the present application is to provide a camera capable of minimizing a change in battery characteristics due to a temperature change.

An object of a second invention according to the present application is to provide a camera capable of promoting the heat generation of the battery itself, activating the battery, and improving the characteristics of the battery at low temperatures. It is.

An object of a third invention according to the present application is to provide a camera capable of easily and accurately obtaining a strobe light emission operation according to various functions of the camera.

A fourth object of the present invention is to extend the time during which the battery itself generates heat and to prolong the period during which the battery is activated at a low temperature, thereby improving the characteristics of the battery during photography. A camera that maintains the state is provided for use.

An object of a fifth invention according to the present application is to simplify the circuit of a camera, extend the time during which the battery itself generates heat, and prolong the period during which the battery is activated at a low temperature to capture an image. It is an object of the present invention to provide a camera that can maintain the characteristics of a battery in a better state.

An object of a sixth invention according to the present application is to extend the time during which the battery itself generates heat, extend the period during which the battery is activated at a low temperature, and control this period more finely. An object of the present invention is to provide a camera that can maintain the characteristics of a battery at the time of shooting in a better state.

[0018]

A camera for realizing the object of the first invention according to the present invention comprises an ambient temperature measuring means for measuring an ambient temperature of the camera, and a strobe light emission control based on input information. Automatic light emission setting means for changing the light emission reference level for determining whether the strobe light is emitted or not in accordance with the output of the ambient temperature measuring means.

According to this configuration, by changing the light emission reference level of the automatic light emission setting means in accordance with the output of the ambient temperature measuring means, it is possible to minimize the change in the battery characteristics due to the temperature fluctuation. .

According to a second aspect of the present invention, there is provided a camera according to the first aspect, wherein the automatic light emission setting means raises a light emission reference level when an ambient temperature is low, and performs a strobe light emission operation. Is set so as to increase the possibility.

According to this configuration, the automatic light emission setting means includes:
When the ambient temperature is low, the automatic flash level is increased to make it easier for the strobe to emit light, thereby stimulating the heat generation of the power battery itself. Characteristics can be improved.

In the configuration of the camera for realizing the object of the third invention according to the present application, in each of the above-mentioned configurations, a control means for controlling the camera and a strobe means for emitting light in accordance with the control of the control means are provided. A photometric means for measuring the subject brightness,
Film information detecting means for detecting the sensitivity information of the photographic film, and the automatic light emission setting means includes an output of the photometric means, an output of the film information detecting means, a strobe light emission according to the intrinsic data of the photographic optical system, and the like. Non-light emission is determined.

According to this configuration, a strobe light emitting operation corresponding to various functions of the camera can be easily and accurately obtained.

The configuration of the camera for realizing the object of the fourth invention according to the present application includes an ambient temperature measuring means for measuring an ambient temperature of the camera, and a charging operation of the strobe until the charging voltage reaches a predetermined value after the charging operation is started. And a strobe charging operation mode setting means for switching a strobe charging operation mode, wherein an output of the ambient temperature measuring means and an output of the strobe charging operation mode setting means are provided. The operation of the flash charging time varying means is switched according to

According to this configuration, the operation of the strobe charging time varying means is switched in accordance with the output of the ambient temperature measuring means and the output of the strobe charging mode setting means, thereby extending the time during which the battery itself generates heat. As a result, the period during which the battery is activated at a low temperature can be extended, and the characteristics of the battery during shooting can be maintained in a better state.

In the configuration of a camera for realizing the object of the fifth invention according to the present application, in the above-described fourth configuration, the strobe charging time varying means is control means for controlling the camera.

According to this configuration, since the strobe charging time varying means is the CPU itself as the control means for controlling the camera, the circuit of the camera can be simplified and the time required for the battery itself to generate heat can be obtained. Can be extended, and the period during which the battery is activated at a low temperature can be extended, and the characteristics of the battery at the time of shooting can be maintained in a better state.

[0028] In the configuration of a camera for realizing the object of the sixth invention according to the present application, in the above-mentioned fourth configuration, the strobe charging time varying means includes an output proportional to a voltage of a power supply battery, and an output from the control means. Reference voltage setting means capable of changing the output voltage in accordance with the control of the above, comparison means for comparing an output proportional to the battery voltage with an output of the reference voltage setting means, and output and control of the comparison means. And charging means for performing a flash charging operation in response to a charging command from the means.

According to this configuration, the time during which the battery itself generates heat can be extended, the period for activating the battery at low temperatures can be extended, and this period can be more finely controlled, so that the time during photographing can be improved. Battery characteristics can be maintained in a better state.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIGS. 1 and 2 show a first embodiment.

FIG. 1 is a block diagram of a camera according to the present embodiment. Reference numeral 1 denotes a CPU with a built-in A / D converter for controlling the entire camera, 2 denotes a battery voltage detection circuit for detecting the battery voltage of the camera, Indicates charging of the strobe under the control of the CPU 1,
A flash circuit 4 for emitting light, a photometric circuit 4 for measuring the brightness of the object to be photographed, and a temperature detecting circuit 5 for measuring the ambient temperature of the camera.

Reference numeral 6 denotes a film information detecting circuit for detecting the sensitivity of the film to be used, the number of shots, etc., 7 a distance measuring circuit for measuring the distance to a subject to be shot, and 8 a drive of the loaded film. , AL, film control circuit for controlling winding, rewinding, etc., 9 drives the taking lens, lens control circuit for performing the focal length and focus adjustment, 10 drives the shutter, etc. This is an exposure control circuit for giving a fixed amount of exposure and performing photographing.

This camera, when loaded with film,
The film information detected by the film information detection circuit 6 is stored in an EEPROM (not shown). Further, when a main switch (not shown) is turned on, the camera enters a shooting standby state. Here, when it is detected that the first release switch (not shown) is pressed, the camera uses the battery voltage detecting means 2 to
It is determined whether the battery voltage has sufficient capacity to perform the subsequent camera operation. Here, when it is determined that the battery is sufficient, the luminance of the subject is measured by the photometric circuit.

Next, the ambient temperature is measured by the temperature detecting circuit 5, and then the distance to the subject is measured by the distance measuring circuit 7.

After the above processing is completed, when it is detected that the second release switch has been pressed, a correction according to the temperature detection result is made based on the information obtained by the distance measuring circuit 7. The focus control lens is driven by the lens control circuit 9 in accordance with the distance information to the subject, and the exposure control circuit 10 is controlled by the subject brightness information obtained in the photometry circuit 4 and the film-specific sensitivity information. Operate and perform appropriate shutter drive.

At this time, if a specific strobe light emission mode is selected by a strobe mode setting switch (not shown) or the like, the strobe device 3 is operated accordingly. When the exposure operation of the film is completed, the film control circuit 8 executes a film rewinding operation or a rewinding operation when the photographing is the last frame of the film, and waits for the next operation.

In a general auto mode (automatic flash mode), the flash mode emits a flash when an EV value obtained by subject brightness and film sensitivity is equal to or less than a predetermined value. In addition, charging of a main capacitor (not shown) is performed by converting a large amount of battery energy into a high voltage by a DC / DC converter in order to make the strobe emit light, and the current supplied from the battery to the DC / DC converter during charging is The number A is reached. This current flows through the internal resistance of the battery itself, causing a phenomenon that the battery itself generates heat.

In this embodiment, the EV value at which the strobe is automatically fired is changed according to the temperature, that is, the emission brightness is increased only when the temperature is lower than the normal temperature, and the charging and emission of the strobe are performed. Is more likely to be performed. By doing so, the possibility that the battery itself generates heat is increased only at low temperatures.

The operation of this embodiment will be described below with reference to the flowchart shown in FIG.

In the camera shown in the block diagram of FIG.
A first release switch (not shown) (hereinafter referred to as a switch SW1)
Is operated (step 101), the CPU performs A / D conversion of the battery voltage while a predetermined load current is applied to measure the battery voltage (step 102).

In step 103, the measurement result of the battery voltage obtained here is compared with a predetermined value stored in advance to determine whether or not there is sufficient capacity for performing the subsequent camera operation.

If it is determined that the battery voltage is insufficient,
The CPU gives a warning display to that effect on display means (not shown),
Subsequent operations are prohibited (step 104), and the process waits for the next operation (step 120).

On the other hand, if it is determined that the battery voltage is sufficient, the output voltage of the
/ D conversion and measure the subject brightness. Then step 10
At 6, the output of the temperature detection circuit 5 is A / D converted, the ambient temperature is measured, and the routine proceeds to step 7.

In step 107, the distance measuring circuit 7 is driven to measure the distance to the subject.

Next, at step 108, it is determined whether or not the second release switch (hereinafter, referred to as a switch SW2) has been pressed. In practice, the switches SW1,
The switch SW2 may be pressed all at once, and such a flow cannot cope with such a case. However, the description will be simplified in this manner.

If the switch SW2 is not turned on, the switch SW2 is turned on or the switch S2 is turned on.
It waits until W1 is turned off (step 109).

When the switch SW2 is detected to be on, the photographing sequence is started. Before that, the ambient temperature condition in step 110 is determined.

In step 110, it is determined whether the previously measured ambient temperature is lower or higher than normal temperature. here,
It is determined whether or not the ambient temperature is 0 degrees Celsius or more. If the temperature is 0 degrees Celsius or more, the process proceeds to Step 112. If the temperature is 0 degrees Celsius or less, the process proceeds to Step 111.

That is, if it is determined in step 110 that the ambient temperature is high, the object luminance obtained from the previously measured object luminance and the film sensitivity obtained and stored by the film information detecting means in advance. EV
The value comparison reference value is set to EV5 (step 112).

On the other hand, if it is determined in step 110 that the temperature is low, a comparison value between the previously measured subject brightness and the EV value of the subject obtained from the film sensitivity previously obtained and stored by the film information detecting means. The reference is set to EV10 (step 111).

Next, at step 113, the EV value of the subject obtained from the previously measured subject brightness and the film sensitivity previously obtained and stored by the film information detecting means is larger than the previously set comparison reference value. Is smaller or smaller.

Here, if the EV value of the subject is smaller than the comparison reference value, ST
Set the flag named ON to 1 (step 1
14).

In this case, a time-consuming charging operation is immediately performed (step 116).

On the other hand, if the EV value of the subject is larger than the comparison reference value, the flag STON is set to 0 in order to make the strobe not emit light (step 11).
5) The process proceeds to step 117 without charging the strobe.

In step 117, the lens control circuit 9 is driven so as to move the focus adjusting lens to a position where the subject distance previously obtained is corrected according to the ambient temperature.

Next, in step 118, the exposure control circuit 10 controls the exposure control circuit 10 so that the shutter opening time is appropriate for the presence / absence of strobe light emission and the previously obtained EV value of the subject, and drives the shutter. . At this time, the strobe light is emitted at an appropriate timing according to the value of the flag STON.

When the exposure control is completed, the film feeding control is performed in step 119, and the film is wound up one frame, or the rewinding operation is performed when the photographed frame is the last frame.

Upon completion of the above operation, the flow shifts to a state of waiting for the next switch operation (step 120).

That is, in the present embodiment, at low temperatures, if the EV value is equal to or less than EV10, which is the comparison reference value, the strobe light is emitted. Otherwise, the EV value is EV5, which is the comparison reference value. If it is below, the strobe light is emitted. That is, at low temperatures, the strobe light is more actively emitted, and the charging operation is performed. By supplying a large load current from the battery in this manner, the chances of causing the battery itself to generate heat are increased.

Once heat is generated, activation of the battery itself proceeds,
Since the battery voltage is less likely to drop when a battery check is performed when performing the following operations, it is more difficult for the battery check to determine that the battery capacity is insufficient than when the charging operation is not performed immediately before, and shooting is performed somewhat continuously. If you do
That is, in the case where the photographing is performed at intervals such that the battery temperature is kept higher than the ambient temperature, the number of photographable images is greatly increased. Also, the reliability of the battery check itself is not affected at all.

(Second Embodiment) FIG. 3 shows a second embodiment.

The configuration of the camera according to the present embodiment is shown in FIG.
FIG. 3 shows a detailed configuration of a strobe device similar to that of FIG.

In FIG. 3, reference numeral 31 denotes a CPU (CP in FIG. 1).
U1), a charge completion signal 32 for notifying the CPU that a predetermined amount of charge has been completed, and a charge completion signal 33 for CP.
A light emission signal from U, 34 is a reference voltage setting signal from the CPU for setting a reference voltage for comparing the battery voltage, 35
Is a battery voltage signal output from the battery voltage detection circuit and proportional to the battery voltage.

Reference numeral 36 charges the strobe capacitor 42 with a high voltage in response to the charging signal.
Is charged to a predetermined voltage, a DC / DC converter that outputs a charge completion signal 32, 37 is a trigger circuit for discharging the electric charge of the strobe capacitor 42 to the discharge tube 38 according to the light emission signal 33, and 39 is A reference voltage setting circuit for switching the output voltage according to the reference voltage setting signal 34, a comparator 40 for comparing a battery voltage signal with an output of the reference voltage setting circuit, and a reference numeral 41 for a two-input AND gate.

In FIG. 3, first, reference voltage setting circuit 39
Will be described.

Reference voltage setting signal 3 output from CPU
4 is set to “1”, the reference voltage setting circuit 3
Reference numeral 9 denotes a first output voltage, for example, 1.0 V. On the other hand, when the reference voltage setting signal 34 is set to “0”, the reference voltage setting circuit 39 outputs a second output voltage, for example, 1.5V.

When "1" is set to the reference voltage setting signal 34 and the output is 1.0 V, the charge signal 3
Consider the case where 1 is output. The battery voltage signal 35
In this embodiment, it is assumed that the battery voltage is directly output.

The comparator 40 determines the battery voltage itself,
The output of the reference voltage setting circuit 39 is compared.

When the battery voltage is higher than the reference voltage setting circuit 39 output of 1.0 V, the output "1" is output. Then, both inputs of the two-input AND gate 41 become "1" and output "1". The DC / DC converter 36 starts charging operation since "1" is input to its control input.

When the DC / DC converter 36 starts operating, a current of several A flows from the battery into the DC / DC converter 36. For this reason, the output voltage of the battery decreases according to the flowing current due to its own internal resistance.

If the battery voltage drops extremely, a problem occurs in the operation of the control circuit including the CPU.
When the output falls below 9, the charging operation is stopped.

That is, when the battery voltage drops and becomes lower than the output of the reference voltage setting circuit 39, the output of the comparator 40 becomes "0". Then, since one of the inputs of the two-input AND gate 41 becomes "0", the output also becomes "0".
The operation of the DC / DC converter 36 is stopped. Then, the supply of the large current from the battery is stopped, the battery voltage recovers, the output of the comparator 40 becomes “1” again, and the DC / DC converter 36 repeats the operation of restarting the charging operation.

While repeating this, the strobe capacitor 42 is charged to a predetermined voltage, and the DC / DC converter 36 sets the charge completion signal 32 to "1". CP
U confirms that the charge completion signal has been set to “1”, sets the charge signal 31 to “0”, and sets the light emission signal 3
Wait for 3 to be set to "1".

The state of the above operation is shown in the timing chart of FIG.

Although the comparator 40 has no hysteresis, the comparator 4 has a small delay due to a response delay of the circuit system.
The intermittent charge state according to the output of 0 is continued.

Next, when the reference voltage setting signal 34 becomes "0", the output of the reference voltage setting circuit 39 becomes 1.5 V as described above.

In this case, since the current flowing into the DC / DC converter 36 is further restricted, the reference voltage becomes 1.0 V before the capacitor reaches the predetermined voltage.
More time is required than in the case of. This is shown in FIG.

As described in the first embodiment, when the release switch such as the switch SW1 or the switch SW2 is operated, if the strobe light emission is required, the strobe is charged immediately. Also, the strobe charging operation is performed in various cases in the operation of the camera.

Generally, when the flash operation is started after the release operation is performed, the shutter operation cannot be performed for a while until the charging is completed, so that a release time lag occurs. Therefore, in order to avoid this, the flash is charged as much as possible before the release switch is operated, and the time required for charging the flash after the release operation is performed is reduced as much as possible, so-called preliminary charging operation. Has been done.

For example, a method of completing charging of the flash once, for example, immediately after the main switch is turned on, after completion of a film winding operation after flash emission, or the like is performed.

In this embodiment, in the flash charging operation when the release switch is pressed, the output voltage of the comparison reference voltage is lowered to perform a high-speed charging operation, to improve operability, and to perform other operations. At the time of pre-charging, the output voltage of the comparison reference voltage is set high and the charging operation is performed over time, so that the time for supplying the load from the battery is prolonged, the time for the battery to generate heat is prolonged, and the battery is activated. This is to maintain the time that is spent.

FIG. 6 shows a flowchart of the operation at the time of the above-mentioned preliminary charging.

At step 201, a precharge sequence is started. First, in step 202, the ambient temperature is measured. Next, in step 203, it is determined whether the ambient temperature is low. For example, in the present embodiment, it is determined whether the ambient temperature is 0 ° C. or higher.

If the ambient temperature is 0 ° C. or higher, step 2
At 04, the reference voltage setting signal is set to "1", the output is set to 1.0 V, and the same charging operation as usual is performed. On the other hand, when the ambient temperature is lower than 0 ° C., the reference voltage setting signal is set to “0”, and the output of the reference voltage setting circuit 39 is set high, for example, 1.5V. By doing so, DC
The current supplied to the / DC converter 36 is limited.

Next, at step 206, the charging signal is set to "1", and the operation of the DC / DC converter 36 is started.

Next, at step 207, it is determined whether or not the charging voltage of the strobe capacitor has reached a predetermined value, that is, the charging operation is completed, and the charging completion signal whose initial value is "0" becomes "1". Is determined. While waiting for the charge completion signal to change, it is checked in step 208 whether any other operation switch has been operated.

If any one of the operation switches has been operated, the charging signal is set to "0" in step 211 to stop the strobe charging operation, and the operation corresponding to each operation switch is performed (step 213). .

If the charging operation cannot be completed within a predetermined time after the start of the charging operation of the strobe (step 209), the charging signal is set to "0" for safety.
The operation of the DC / DC converter 36 is stopped to stop the charging operation, and in step 214, a warning is displayed on a display unit (not shown), and the next operation is waited.

On the other hand, when it is confirmed in step 207 that the charge completion signal has become "1", the charge signal is set to "0" in step 210, the strobe charging operation is stopped, and the next operation is performed. wait.

In the precharge operation described above, in the routine in which the release switch such as the switch SW1 or the switch SW2 is operated as in the first embodiment, when the charging operation of the strobe is performed, the ambient temperature is changed. Regardless of this, it goes without saying that the charging operation is performed after setting the reference voltage setting signal to "1" and lowering the reference voltage so as not to impair the operability.

In this embodiment, only when the ambient temperature is low, the reference voltage for comparing the battery voltage is changed, and the charging operation of the strobe is intermittently controlled in accordance with the comparison result. Although the charging time is changed, even without such a comparison circuit, for example, during preliminary charging at a low temperature, the strobe charging operation is repeatedly performed by the CPU at predetermined time intervals. It goes without saying that the same effect as in the present embodiment can be obtained by controlling.

In this embodiment, the comparison reference voltage is switched in two stages. However, the control can be finely controlled according to the ambient temperature or the like by using finer switching or using a D / A converter output or the like. It is possible to do.

[0093]

According to the first aspect of the present invention, the change of the battery characteristics due to the temperature fluctuation is minimized by changing the light emission reference level of the automatic light emission setting means according to the output of the ambient temperature measuring means. You can do so.

According to the second aspect of the present invention, the automatic light emission setting means raises the automatic light emission level when the ambient temperature is low so that the strobe can emit light more easily. Is promoted, the battery is activated, and the characteristics of the battery at low temperatures can be improved.

According to the third aspect of the present invention, a strobe light emission operation corresponding to various functions of the camera can be easily and accurately obtained.

According to the fourth aspect of the present invention, the operation of the strobe charging time varying means is switched according to the output of the ambient temperature measuring means and the output of the strobe charging mode setting means, so that the battery itself generates heat. It is possible to extend the time for performing the activation of the battery at a low temperature, and to maintain the characteristics of the battery at the time of photographing in a better state.

According to the fifth aspect of the present invention, since the strobe charging time varying means is the CPU itself which is the control means for controlling the camera, the circuit of the camera can be simplified and the battery itself can be simplified. It is possible to prolong the time during which the battery generates heat and to prolong the period during which the battery is activated at a low temperature, and to maintain the battery characteristics during photography in a better state.

According to the invention of claim 6, it is possible to prolong the time during which the battery itself generates heat, to prolong the period during which the battery is activated at low temperatures, and to control this period more finely. Thereby, the characteristics of the battery at the time of shooting can be maintained in a better state.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a flowchart according to the first embodiment of the present invention.

FIG. 3 is a detailed block diagram of a strobe circuit according to a second embodiment of the present invention.

FIG. 4 is a timing chart showing the operation of each unit according to the second embodiment of the present invention.

FIG. 5 is a timing chart showing the operation of each unit according to the second embodiment of the present invention.

FIG. 6 is a flowchart according to the second embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 CPU 2 battery voltage detection circuit 3 strobe circuit 4 photometry circuit 5 temperature detection circuit 6 film information detection circuit 7 distance measurement circuit 8 film control circuit 9 lens control circuit 10 exposure control circuit 31 Charge signal 32 Charge completion signal 33 Light emission signal 34 Reference voltage setting signal 25 Battery voltage signal 36 DC / DC converter 37 Trigger circuit 39 Reference voltage setting circuit 40 Comparator 41 2-input AND
Gate

Claims (6)

[Claims] 1. An image forming apparatus comprising: an ambient temperature measuring unit for measuring an ambient temperature of a camera; and an automatic light emitting setting unit for controlling light emission of a strobe based on input information. A camera characterized in that a light emission reference level for determining whether or not to emit light from a strobe is changed according to an output. 2. The automatic light emission setting means according to claim 1, wherein the automatic light emission setting means increases the light emission reference level when the ambient temperature is low,
A camera characterized in that it is set so as to increase the possibility of strobe light emission operation. 3. A camera according to claim 1, wherein said control means controls a camera, a flash means emits light in accordance with the control of said control means, a photometric means for measuring subject brightness, and sensitivity information of a photographic film. The automatic light emission setting means determines whether the strobe light is emitted or not in accordance with the output of the photometry means, the output of the film information detection means, the unique data of the photographing optical system, and the like. Camera. An ambient temperature measuring means for measuring an ambient temperature of the camera; a flash charging time varying means for changing a time required for a charging voltage to reach a predetermined value after a flash charging operation is started; A strobe charging operation mode setting unit for switching a charging operation mode, wherein an operation of the strobe charging time varying unit is switched according to an output of the ambient temperature measuring unit and an output of the strobe charging operation mode setting unit. And the camera. 5. The camera according to claim 4, wherein the flash charging time varying means is control means for controlling the entire camera. 6. A strobe charging time varying means according to claim 4, wherein said strobe charging time varying means includes an output proportional to a voltage of a power supply battery, a reference voltage setting means capable of changing an output voltage according to control from said control means, An output proportional to the battery voltage;
Comparing means for comparing the output of the reference voltage setting means,
A camera comprising: a charging unit that performs a strobe charging operation in response to an output of the comparison unit and a charging command from the control unit.