JP3701923B2 - camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
More particularly, the present invention relates to a camera having a clock means capable of correcting the time using a standard radio signal. Here, the standard radio wave signal is a radio wave signal transmitted as a signal in which standard time in Japan or a foreign country is encoded.
[0002]
[Prior art]
As for the time displayed on the camera, the time once input to the camera by an operator or the like is updated based on oscillation of a fixed period such as an oscillator provided inside the camera. However, the oscillation of the oscillator or the like varies in the period depending on the ambient temperature state and the like, so that a time lag occurs. In order to correct such a shift, it is conceivable to correct the time in the apparatus using a standard radio signal. An optical disc image disclosed in Japanese Patent Application Laid-Open No. 2001-208877 is disclosed as an apparatus having a function of receiving a standard radio signal and readjusting the internal time based on the standard time which is data of the standard radio signal. Recording devices are known.
[0003]
[Problems to be solved by the invention]
However, this optical disc video recording device receives the standard radio signal at regular intervals and corrects the time inside the device, but there is a problem that the standard radio signal cannot be received well due to a lot of noise in the daytime. .
[0004]
The present invention has been made in view of such circumstances, and an object thereof is to receive a standard radio wave signal in a good reception environment.
[0005]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a camera having a clock means capable of receiving a standard radio signal and correcting the time based on the standard time which is data of the standard radio signal. Photometric means for measuring brightness, and brightness determination means for comparing the brightness measured by the photometry means with a predetermined reference brightness to determine whether the brightness measured by the photometry means is lower than the reference brightness And a standard radio wave signal is received to correct the time of the clock means when the luminance measured by the photometric means is determined to be lower than the reference luminance by the luminance determining means. .
[0006]
In such a configuration, the standard radio signal is received only when the brightness around the camera is lower than the reference brightness, that is, darker than the set brightness, and the time in the camera can be corrected.
[0007]
Also, as described above, there is a lot of noise during the daytime and the reception state is bad, but since the noise is reduced compared to the daytime at night, the reception state of the standard radio signal is good. For this reason, setting the reference luminance to be the luminance around the camera at night is preferable in that the standard radio signal can be received at night in a good reception environment.
[0008]
Furthermore, the image forming apparatus includes a photographing determination unit that determines that photographing has been performed, and when the luminance determination unit determines that the luminance from the photometry unit is lower than the reference luminance, the photographing determination unit performs photographing. It is also preferable to receive a standard radio signal immediately after it has been determined that the time has been taken, because the time is corrected only when the image is taken, and power consumption is reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing an electrical configuration of a camera according to an embodiment of the present invention.
[0010]
The camera 10 according to the present embodiment includes a CPU 12 that is a microprocessor including a ROM, a RAM, and the like, and is controlled by the CPU 12. Connected to the CPU 12 are a power switch 14, a light detection element (photometric means) 16, a receiving circuit 18, a shutter button 20, a date copying unit 22, and the like.
[0011]
The power switch 14 is a main switch of the camera 10. When the power switch 14 is pressed and turned on, the above functions of the camera 10 connected to the CPU 12 function.
[0012]
The light detection element 16 performs so-called photometry, which measures the brightness of the object scene (subject) at the time of shooting, that is, the luminance around the camera 10. The light detection element 16 is provided in the camera 10 main body, detects light incident on the camera 10 and outputs it to the CPU 12 as luminance. In this embodiment, CdS (cadmium sulfide) is used as the light detection element.
[0013]
An antenna 19 for receiving a radio signal is connected to the receiving circuit 18. The receiving circuit 18 selects a standard radio signal from various radio signals that reach the antenna 19 and outputs the standard radio signal to the CPU 12 (hereinafter referred to as “receive standard radio signal”). Note that the standard radio signal includes information such as hour, minute, day of the year (the day of January 1), year (last two digits).
[0014]
The shutter button 20 outputs an SP1 signal for starting photometry and the SP2 signal for performing photographing to the CPU 12. The SP1 signal is output to the CPU 12 when the shutter button 20 is half pressed, and the SP2 signal is output to the CPU 12 when the shutter button 20 is further pressed from the half pressed state. In this specification, the state in which the SP1 signal is output to the CPU 12 is referred to as SP1 being in the on state, and the state in which the SP2 signal is output to the CPU 12 is referred to as being in the on state.
[0015]
The date imprinting unit 22 is for imprinting the date and time when the photographing was performed on the photographed film or the like. The displayed date and time is obtained by converting a signal output from the clock means in the CPU 12 into date and time. Although not shown, a signal output from the clock means is also sent to a clock display or the like provided on the back cover of the camera 10 and displayed as the date and time.
[0016]
The CPU 12 processes a program written in the ROM, thereby determining whether or not the power switch 14 is in the ON state, and determining the brightness around the camera 10 measured by the light detection element 16 ( Hereinafter, luminance determination for determining whether or not “measured luminance” is lower than a predetermined reference luminance, and shooting determination for determining whether or not shooting has been performed can be performed. Further, the CPU 12 has a clock means. The clock means counts time based on an oscillation signal having a fixed period by an oscillator or the like (hereinafter, the counted time is referred to as “time signal”). In addition, when the standard radio signal is received, the clock means converts the standard radio signal data into time information (hereinafter referred to as “standard time signal”), and compares the time signal with the standard time signal. When there is a time signal, the time signal is corrected with the standard time signal.
[0017]
FIG. 2 shows the time correction processing procedure of the camera 10 by the CPU 12. The operation related to the time correction process of the camera 10 will be described with reference to FIG. When the CPU 12 determines that the power switch 14 is in the on state (“YES” in S100), the shutter button 20 is half-pressed and SP1 is turned on (“YES” in 102). Then, photometry is performed by the light detection element 16 (S104), and the luminance around the camera 10 is input to the CPU 12. Then, the measured luminance obtained by the light detection element 16 is compared with a predetermined reference luminance, and it is determined whether or not the measured luminance is lower than the reference luminance (S106). The reference luminance is a fixed value set in advance. In this embodiment, the reference luminance is set to the luminance around the camera 10 at night. Further, the CPU 12 further determines a shutter speed and the like based on the measured luminance.
[0018]
A case will be described in which the measured luminance is determined to be lower than the reference luminance (“YES” in S106).
[0019]
In this case, it is determined again whether SP1 is in the ON state (S107). If it is determined that SP1 is on ("YES" in S107), it is determined whether SP2 is on (S108). Here, when the shutter button 20 is further pressed from the half-pressed state and the SP2 is turned on (“YES” in S108), photographing is performed (S110). If it is determined that shooting has been performed because SP2 is turned on, a standard radio signal is received (S112). If SP2 is not on ("NO" in S108), the process returns to S107.
[0020]
The received standard radio signal is input to the CPU 12 and the standard radio signal data is converted into a standard time signal. When the reception of the standard radio signal is established (“YES” in S114), when the time signal and the standard time signal are compared and there is a deviation, the time signal is corrected by the standard time signal (S116). The corrected time signal is displayed on the film taken as the date and time when it was taken, via the date imprinting unit 22.
[0021]
If the reception of the standard radio signal is not established (“NO” in S114), the time signal in the camera 10 is not corrected by the standard radio signal.
[0022]
Next, a case where the measured luminance is determined to be higher than the reference luminance (“NO” in S106) will be described.
[0023]
In this case, it is determined again whether SP1 is in the ON state (S117). If SP1 is on (“YES” in S117), it is determined whether SP2 is on (S118). Here, when the shutter button 20 is further depressed from the half-pressed state and the SP2 is turned on (“YES” in S118), shooting is performed (S120), and the time correction process is performed without receiving the standard radio wave signal. Ends. If SP2 is not on ("NO" in S118), the process returns to S117. If SP1 is not in the ON state (“NO” in S117), the shooting is not performed and the time correction process is terminated without receiving the standard radio signal.
[0024]
When the CPU 12 determines that the power switch 14 is not turned on (“NO” in S100), or when SP1 is not turned on (“NO” in S102, “NO” in S107), The standard radio signal is not received and the time signal is not corrected.
[0025]
Thus, in the present embodiment, the time signal updated inside the camera 10 is corrected using the standard radio signal only when the brightness around the camera 10 is lower than the reference brightness. Since the reference luminance is set to the luminance around the camera 10 at night, the standard radio signal can be received at night when the reception state of the standard radio signal is good. Moreover, since it is a forced reception received only when the above-described conditions are satisfied, power consumption can be suppressed.
[0026]
When SP1 is on, automatic adjustment of the focal position, determination of the shutter speed, and the like are performed for shooting. Therefore, if a standard radio signal is received in this state, reception may be a noise source for automatic adjustment of the focal position, etc., and automatic adjustment of the focal position, etc. will be a noise source for reception. There is a case. On the other hand, in the present embodiment, the reception of the standard radio wave signal is started immediately after it is determined that the photographing has been performed, so the standard radio wave signal does not become a noise source for automatic adjustment of the focal position. Furthermore, since the camera 10 is in a stable state after shooting, it does not become a noise source even when receiving a standard radio signal.
[0027]
As mentioned above, although preferred embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to the said embodiment.
[0028]
For example, in the above embodiment, a preset value is used as a fixed value as the reference luminance when determining whether or not the measured luminance is lower than a predetermined reference luminance. However, it is also conceivable to use the measured brightness at the previous photographing as the reference brightness. In this case, the previous measured luminance may be stored in a storage area in the CPU 12, for example.
[0029]
FIG. 3 shows a flowchart in the case of this embodiment. In FIG. 3, the operation from S100 to S104 is the same as that in FIG. 2, and when the power switch 14 is on and SP1 is on, photometry is performed. The data (luminance) measured in S104 is stored in the CPU 12 (S122). Then, it is determined whether or not the latest measured luminance is lower than the previous measured luminance (S124). When it is determined that the latest measured luminance is lower than the previous measured luminance (“YES” in S124), the standard radio signal is received according to the procedure of S107 to S116, and the time signal in the camera 10 is corrected. The
[0030]
When the latest measured luminance is higher than the previous measured luminance (“NO” in S124), the photographing is performed in accordance with S117 to S120 similarly to FIG. When 14 is turned off (“YES” in S126), the time signal updated in the camera 10 is not corrected by the standard radio signal.
[0031]
On the other hand, when the state where the power switch 14 of the camera 10 is turned on is maintained after the photographing is finished (“NO” in S126), the process returns to S102.
[0032]
As described above, in the present embodiment, by comparing the latest measured brightness with the previous measured brightness, when the latest measured brightness is lower than the previous measured brightness, that is, the periphery of the camera 10 is the previous measured brightness. Receive standard radio signals when it is darker than when shooting. Accordingly, it is possible to receive the standard radio signal in a time zone closer to the night when the reception environment is good. When determining whether or not the brightness is low, a numerical value unique to the previous measured brightness may be added. This is because the time can be corrected at night without depending on the time zone in which the previous shooting was performed.
[0033]
In the above embodiment, CdS is used as a light detection element for measuring the luminance around the camera 10, but various light sensors can be used as the light detection element.
[0034]
Furthermore, in the above-described embodiment, a camera that has started photometry by pressing the shutter button halfway is targeted. However, the present invention is not limited to such a camera, and other types of cameras that perform photometry, For example, you may apply to the camera etc. which react to an audio | voice.
[0035]
Furthermore, in the above embodiment, whether or not shooting has been performed is determined in the SP2 state, but it is not necessary to be limited to this. For example, various forms such as detecting the operation of the shutter itself are conceivable.
[0036]
In any of the embodiments, the camera may be any type of camera such as a silver salt camera, a digital camera, or a video camera.
[0037]
【The invention's effect】
According to the present invention, since the standard radio signal is received when the brightness around the camera is lower than the predetermined reference brightness, the standard radio signal can be performed at night when the radio wave reception environment is good by setting the reference brightness. Therefore, it is possible to receive the standard radio signal satisfactorily. In addition, if the standard radio signal is received immediately after shooting, power consumption can be reduced compared to the case where the standard radio wave is received at regular intervals and the time is corrected.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an electrical configuration of a camera 10 according to the present invention. FIG. 2 is a flowchart for explaining a time correction processing procedure of the camera 10 according to the present invention.
FIG. 3 is a flowchart for explaining a time correction processing procedure when the previous measured luminance is used as the predetermined reference luminance in the operation of FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Camera, 12 ... CPU, 14 ... Power switch, 16 ... Photodetection element (photometry means), 18 ... Reception circuit, 19 ... Antenna, 20 ... Shutter button, 22 ... Date imprint part

Claims (3)

In a camera having a clock means capable of receiving a standard radio signal and correcting the time based on the standard time which is data of the standard radio signal,
Photometric means for measuring the brightness around the camera;
A luminance determination unit that compares the luminance measured by the photometry unit with a predetermined reference luminance to determine whether the luminance is lower than the reference luminance;
With
A camera configured to receive a standard radio signal so as to correct the time of the clock means when the luminance determination means determines that the luminance measured by the photometry means is lower than the reference luminance. Provided with a photographing determination means for determining whether photographing has been carried out,
The standard radio wave signal is determined when the brightness measured by the photometry means is determined to be lower than the reference brightness by the brightness determination means, and immediately after the shooting determination means determines that shooting is finished. The camera according to claim 1, wherein the camera is received. The camera according to claim 1, wherein the reference luminance is a luminance around the camera at night.

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