JP2002176570A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera which incorporates a stroboscope and inhibits a user from replace a battery and reduces the allowable number of pictures to be photographed at the time of consumption of the battery. SOLUTION: The digital camera is provided with a display part which displays the allowable number of pictures to be photographed, a battery capacity detection means which detects the battery capacity, and a control means which calculates the allowable number of pictures to be photographed on the assumption of stroboscopic photographing on the basis of the battery capacity detected by the battery capacity detection means and displays this allowable number on the display part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera having a built-in strobe so that a user cannot replace a battery.

[0002]

2. Description of the Related Art With the spread of personal computers, many digital cameras that convert a captured image into an image signal and store the image signal are commercially available. Users can import images taken with a digital camera to a personal computer and use them as photos on a homepage, create a New Year's card with photos, or print them with a printer, so the application range is extremely wide. .

In recent years, digital cameras have become quite widespread, but since they have built-in image pickup devices such as CCDs, memories, processing circuits, and the like, they are considerably more expensive than cameras using films. Some digital cameras are sold at a particularly low price, but the number of pixels of the image sensor is not so large, and they are only viewed on a display at best, and the image is too coarse for printing.

[0004] In addition, there are times when it is desired to record using a digital camera while traveling, but it is not possible to easily purchase an expensive digital camera. In view of the above, there is a demand for a digital camera which can be easily purchased at a low cost, such as a film unit with a lens, and which can obtain a high quality image which can sufficiently withstand viewing when printed.

In the case of a film unit with a lens, when a user finishes photographing, the manufacturer collects the photographing via a lab and reuses it as much as possible.

Therefore, in order to supply a digital camera which is inexpensive and can provide good image quality, a digital camera which is supposed to be reused like a film unit with a lens has been disclosed in Japanese Patent Application Laid-Open No. 2000-196931. I have.

[0007]

When a digital camera is reused like a film unit with a lens,
It is roughly as follows. That is, an image captured by the user using this digital camera is stored as an image signal in a memory as an internal recording medium, but the user cannot read the image signal from the memory and writes the image signal on a removable memory card. It is a configuration that can not do it.

[0008] Then, the user brings the digital camera having the image signal stored in the memory to a store corresponding to a camera store or a DPE store. Then, in the store or at a place such as a lab where there is a transaction with the store, the image signal is read out from the digital camera and printed out, or written to an external recording medium such as a magnetic disk or a memory card, so as to be provided to the user. hand over. This allows the user to obtain a print or import the image to a personal computer. This external recording medium may be one prepared by a store or the like, or one brought in by a user.

On the other hand, in a store or the like, the image signal is erased from the memory, and the digital camera is collected by a manufacturer. Note that the erasure of the image signal may be performed by the manufacturer. The manufacturer inspects all parts and reuses usable parts for newly produced digital cameras. Since a digital camera has few mechanical parts unlike a film unit with a lens, there are generally few parts that fail. But,
Exterior parts are often not reusable due to scratches or dirt.

In order to establish a digital camera reuse system as described above, it is necessary to encrypt an image signal stored in a memory of the digital camera so that the user cannot decrypt the image signal, and further read the image signal. Requires a specific password.

Further, in order to manufacture a digital camera at low cost, it is desirable to use a DRAM having a high storage speed and a low price in a memory. However, a DRAM has a property that stored image signals are erased when power supply is cut off. Therefore, it is necessary to have a structure in which a user cannot take out a battery as a power supply carelessly.

Furthermore, since a low-brightness subject may be photographed using a digital camera, it is necessary to incorporate a strobe. However, when a strobe is charged, a large current flows from a battery serving as a power supply, so that the strobe consumes more power than other electronic components. Therefore, if the user repeatedly charges the strobe more than necessary, the battery will be exhausted and it will not be possible to take the specified number of shots. When a DRAM is used, there is a risk that stored image signals may be erased due to battery exhaustion.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and is directed to a digital camera having a built-in strobe so that a user cannot replace a battery, wherein the number of remaining shots is reduced when the battery runs out. A first object is to propose a digital camera that performs display, and a second object is to propose a digital camera that prohibits the emission of strobe light in the remaining photographing when the battery is exhausted.

[0014]

The first object is achieved by the following means.

A digital camera having a built-in strobe so that a user cannot replace a battery, a display unit for displaying a remaining number of pictures that can be taken, a battery capacity detecting unit for detecting a battery capacity, and the battery capacity detecting unit. Control means for calculating the number of remaining images on the assumption that all flash shooting is performed based on the battery capacity detected by the means, and displaying the remaining number on the display unit. .

The second object is achieved by the following means. A digital camera having a built-in strobe and configured so that a user cannot replace a battery, wherein a battery capacity detecting means for detecting a battery capacity and a battery capacity detected by the battery capacity detecting means is equal to or less than a predetermined battery capacity. Is
Control means for controlling the strobe so as to prohibit the emission of the strobe in subsequent photographing.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments of a digital camera will be described below. Prior to a detailed description, a basic configuration of the digital camera will be described with reference to a block diagram of FIG.

Reference numeral 11 denotes a photographing lens. An optical image of a subject is formed on the image pickup device 12 by the photographing lens 11. The imaging element 12 may be a CCD or a CMOS,
It is desirable that the number of pixels is not less than one million. The optical image is photoelectrically converted into an image signal by the image sensor 12 and stored in the memory 13. Further, since a DRAM is used for the memory 13, the stored image is erased when the power is turned off.

When a digital camera is brought into a store or the like, an image signal is read from the memory 13 and written into an external recording medium such as a magnetic disk or a memory card by a device such as a personal computer in the store. Are connected by the connector 14.

Reference numeral 15 denotes a CPU for controlling each circuit of the digital camera, and reference numeral 16 denotes a display section comprising a liquid crystal plate for displaying the remaining number of images that can be taken. The display unit 16 is small and cannot display a captured image.

When the digital camera is started, the main switch M-SW is turned on, when taking a picture, the release switch R-SW is turned on, and when the taken image is deleted from the memory 13, the erasing switch E-SW is used. Turn on.

Since the digital camera does not have a display for checking a reproduced image or a viewfinder in order to reduce the price, the digital camera 1
Only one image can be deleted.

Reference numeral 17 denotes a battery for supplying power to each of the above circuits. The battery 17 may be any battery,
AA or AAA alkaline batteries that are available at low cost are preferred.

Further, the digital camera has a strobe 18 so that a photograph can be taken even at a low luminance. Strobe 1
Reference numeral 8 denotes an automatic charging circuit that automatically stops charging when charging is completed to reduce battery consumption, an automatic light emitting circuit that automatically emits a strobe light when brightness becomes low to prevent insufficient exposure, and a shooting distance. It is desirable to have a dimming circuit that automatically changes the amount of light emission according to the shooting distance so that the proper exposure is always obtained even if the image changes.

As described above, in this digital camera,
Although the strobe 18 is built in, if the user repeatedly charges the strobe 18 more than necessary, the battery 17 will be exhausted, which may hinder subsequent shooting. For this purpose, a battery capacity detecting means 19 for detecting the capacity of the battery 17 is provided.

Further, since a DRAM is used for the memory 13, there is a risk that the image signal is erased from the memory 13 when the user opens the battery cover or removes the battery 17. In addition, since there is no display, it is impossible to confirm even if the image signal is erased by mistake. Therefore, the digital camera is configured so that the user cannot replace the battery 17 without providing a battery cover.

The control means in the claims corresponds to the CPU 15. [First Embodiment] FIG. 1 is a block diagram showing an embodiment of a digital camera which achieves the above-described first object, and FIG.
This will be described with reference to the flowchart of FIG.

In FIG. 2, when the main switch M-SW is turned on to start the digital camera, a counter display program starts. First, the CPU 15 causes the display unit 16 to display the current number N1 of images that can be photographed (101). If the remaining number N1 is not 0 (N of 102), the capacity of the battery 17 is detected by the battery capacity detecting means 19 (103). Here, a table as shown in Table 1 is stored in the CPU 15.

[0029]

[Table 1]

That is, in the future photographing, it is indicated according to the voltage of the battery 17 whether or not all the remaining images N1 displayed before the capacity detection of the battery 17 can be photographed by flash. N2
Is the remaining number of images that can be taken even if all flash photography is performed after the battery capacity is detected, and changes according to the voltage of the battery 17.

For example, in the battery 17 having a reference voltage of 3 V, if the voltage is 2.8 V or more, N2 = N1;
It is possible to shoot even after detecting the remaining number of sheets before detection,
If the voltage is less than 2.8 V and 2.7 V or more, only 10 pictures can be taken even if there are 20 remaining pictures before detection. If the voltage is less than 2.5 V, it will not be possible to take any number of remaining images before detection.

The CPU 15 refers to such a table to calculate the remaining number N2 when all the flash photography is performed in the future photographing (104), and displays the new remaining number N2 on the display unit 16 (105). ).

When the display is changed to N1 ≠ N2, that is, when the number of remaining images is changed to the number of remaining images N2 smaller than N1, the remaining number of images N1 is notified to notify the user that the number of remaining images is changed due to battery exhaustion. Is flashed a predetermined number of times, and then a new remaining number N2 is displayed.

If the remaining number N2 is not 0 (1
(N of 06), a release button (not shown) is pressed to turn on the release switch R-SW (Y of 107),
After taking an image (108) and storing it in the memory 13 (10
9) The remaining number obtained by subtracting one is displayed on the display unit 16 (110).

Then, until the remaining number becomes 0 (111
N), the above flow is repeated, and when it becomes 0 (11
In 1), the CPU 15 does not accept the release switch R-SW even if it is turned on, and the release becomes impossible (112), and the process ends.

If the number N1 of remaining images that can be photographed at present is 0 (Y in 102) or the number N2 remaining after battery capacity detection is 0 (Y in 106), release is not possible immediately. (112).

As described above, even if the battery is exhausted due to repetitive charging of the flash more than necessary, the battery capacity is detected each time a picture is taken and the remaining number of flash pictures that can be taken is displayed. The user does not miss a precious shutter chance because he thought he could take a picture but could not take the picture.

In the above example, the remaining number N1
Blinks a predetermined number of times, and then displays the new remaining number N2. However, a separate display indicating that the remaining number of images that can be shot may be changed due to battery exhaustion may be provided.

[Second Embodiment] An embodiment of a digital camera which achieves the above-mentioned second object will be described with reference to the block diagram of FIG. 1 and the flowchart of FIG.

In FIG. 3, when the main switch M-SW is turned on to start the digital camera, a counter display program starts. First, the CPU 15 displays the current number of remaining images that can be photographed on the display unit 16 (20).
1). Subsequently, the battery 17 is detected by the battery capacity detecting means 19.
(202). And the reference voltage is 3
V battery 17, the voltage is a predetermined voltage, for example 2.5
If it is equal to or less than V (Y in 203), the CPU 15 causes the strobe 18 to prohibit charging (204), and displays on the display unit 16 that charging is prohibited (205). If not less than 2.5 V (N in 203), the CPU 15 does not prohibit the strobe 18 from charging.

This voltage of 2.5 V is a voltage corresponding to the remaining battery charge that can be used for all remaining images set in the digital camera without using a flash. Therefore, this voltage may be appropriately set depending on the battery used.

When the display unit 16 displays that the charging of the strobe 18 is prohibited (205), the user points the digital camera at the subject to which natural light has been irradiated and presses a release button (not shown). Then, the release switch R-SW is turned on (Y in 206), an image is captured (207), and the image data is stored in the memory 13 (208). It is displayed (209).

Then, the processing is repeated until the remaining number becomes 0 (210), and when it becomes 0 (Y in 210), the CPU 15
Is not accepted even if the release switch R-SW is turned on, the release becomes impossible (211), and the process ends.

Here, a large current flows to charge the strobe, and the power consumption is very large. However, since the power consumption is small unless the strobe is used, the strobe light is emitted even when the battery voltage becomes, for example, 2.5 V or less. As long as the shooting is performed with natural light without performing the shooting, it is possible to shoot all of the planned remaining number.

In the above description, charging of the strobe is prohibited, but light emission of the strobe may be prohibited.

As described above, even if the battery is exhausted by repetition of flash charging more than necessary, the battery capacity is detected each time shooting is performed and whether or not flash shooting can be performed for future shooting is determined and displayed. The photographing of the subject irradiated with the natural light is continued, and the photographing of all the remaining number of sheets scheduled becomes possible.

[0047]

According to the digital camera of the first, fourth, and fifth aspects, even if the battery is exhausted due to repetitive charging of the flash more than necessary, the battery capacity can be detected each time shooting is performed to enable flash photography. Since the remaining number is displayed, the user can take a picture intentionally, and there is no case where the photographer thinks that the picture can be taken but misses a precious shutter chance because he cannot take the picture.

According to the digital camera of the second to fifth aspects, even if the battery is exhausted due to repetitive flash charging more than necessary, it is possible to detect the battery capacity every time shooting is performed and perform flash shooting for future shooting. Since it is determined and displayed, whether or not the subject to which the natural light is irradiated continues to be photographed, and it becomes possible to photograph all of the planned remaining number.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital camera.

FIG. 2 is a flowchart in the digital camera according to the first embodiment.

FIG. 3 is a flowchart in the digital camera according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Image sensor 13 Memory 15 CPU 16 Display part 17 Battery 18 Strobe 19 Battery capacity detection means

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03B 19/02 G03B 19/02 5C052 H04N 5/232 H04N 5/232 Z 5/907 5/907 B // H04N 101: 00 101: 00 F term (reference) 2H053 AC13 AC21 CA41 2H054 AA01 2H100 CC07 DD02 2H102 AA73 AB13 5C022 AA13 AB15 AC13 AC32 AC42 AC52 AC54 AC69 AC73 5C052 AA17 AB02 CC11 DD02 DD08 EE08 GA02 GA03 GA06 GB01 GE06 GE08

Claims (5)

[Claims] 1. A digital camera having a built-in strobe so that a user cannot replace a battery, a display unit for displaying a remaining number of pictures that can be taken, a battery capacity detecting unit for detecting a battery capacity, and the battery. Control means for calculating the remaining number of images on the assumption that all flash shooting is performed, based on the battery capacity detected by the capacity detection means, and displaying the remaining number of images on the display unit. Digital camera. 2. A digital camera having a built-in strobe so that a user cannot replace a battery, wherein a battery capacity detecting means for detecting a battery capacity, and a battery capacity detected by the battery capacity detecting means is a predetermined battery. A digital camera, comprising: a control unit that controls the strobe so as to prohibit the emission of the strobe in the subsequent photographing when the capacity is less than the capacity. 3. The display device according to claim 2, further comprising a display unit for displaying when strobe light emission is prohibited.
A digital camera according to claim 1. 4. The digital camera according to claim 1, wherein a DRAM is used as internal storage means for storing a captured image. 5. The digital camera according to claim 1, wherein the digital camera can be reused by collection.