JPH0365937A - Camera incorporating flashing device - Google Patents

Abstract

PURPOSE:To perform flashing photographing without the waste of energy by providing a detection means which detects the brightness of an object and counter light, etc., and a control means which selects the combination of the emitting light of both incorporated and outside flashing devices based on photographing information obtained from the detection means and controls the light emission. CONSTITUTION:A camera is provided with a microcomputer 4 functioning as the control means. A memory functioning as a storage means is incorporated in the microcomputer 4, and an object distance, the focal distance of a lens, the brightness of the object and object information for judging based on the photographing information whether or not a red-eye phenomenon occurs are previously inputted in the memory. Then, signals from the respective detection means such as an object distance detection sensor 5, a lens focal distance detection sensor 6, an object brightness detection sensor 7 and a counter light detection sensor 8 are inputted in the microcomputer 4. In the case of flashing photographing, the appropriate combination of the emitting light of both of the incorporated and the outside flashing devices 2 and 3 is selected based on various kinds of detected photographing information. Thus, the flashing photographing without the waste of the energy is accomplished.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a camera with a built-in flash that can be used to take pictures by attaching an external flash.[Prior Art] A compact camera that uses current 35 mm film. In Japan, built-in flash types are the mainstream, and 1
In the field of reflex cameras, many products with built-in flashes have recently been announced. However, with this camera with a built-in flash, for reasons such as portability, it is not possible to maintain a large distance between the optical axis of the photographing lens and the light emitting part, and when using the flash, the flash light reflects directly off the retina of the human subject. The probability of "red eye phenomenon" occurring increases.

This red-eye phenomenon occurs when the flash light is regularly reflected by the retina of the human subject's eye, and the probability of red-eye occurrence is:
It is determined by the relationship between the distance IL between the lens optical axis and the light emitting section and the imaging path MD. The relationship is shown in FIG. 4, which shows the cases of L=60 and L=150, and the probability of red eye occurrence is a function of distance and photographing distance. Qualitatively speaking, if the photographing path HD is constant, the distance ML between the photographing lens optical axis and the light emitting section is
The longer the distance, the less likely red-eye will occur, and if the distance 1iiL is constant, the shorter the shooting path HD, the less likely red-eye will occur.
Additionally, even if red eye does occur, it is generally more noticeable as the image magnification is smaller<<; red eye is much more likely to occur in the dark when the pupils are fully dilated than during the day when the pupils are closed. It has been known. From the above, the probability of occurrence of the red-eye phenomenon or its conspicuousness is determined by these photographing conditions.

Therefore, as a measure to prevent red-eye from occurring, even if a single-lens reflex camera has a built-in flash, an accessory shoe is provided on the camera body so that an external flash can be attached, and the distance between the light emitting part and the lens optical axis is adjusted. A method of lengthening the ML has been adopted.

In such cases, it is often the case that only the external flash is activated and the built-in flash is not activated.

As an example of the above, USP No. 4,011,569,
Japanese Unexamined Patent Publication No. 59-58425 is known. As another example, there is a known camera in which the built-in flash can emit light even when an external flash is attached, but the selection of the built-in and external flashes is not controlled depending on the shooting conditions.

[Problems to be Solved by the Invention] Controlling only the external flash to emit light and not the built-in flash as described above prevents red-eye from occurring under conditions where red-eye is likely to occur in the dark. It is effective to some extent.

However, shooting conditions may be better if both the built-in and external flashes are used. For example, red-eye is less likely to occur (hard to stand out) when it is relatively bright even in low brightness, or when the image magnification is small due to the use of a wide-angle lens.
Given the conditions, it is possible to obtain a larger flash guide number value by firing both the built-in and external flashes. In addition, even in backlit conditions during the day, the pupils often close and red-eye will not occur, so it is better to use both the built-in and external flashes to obtain a larger guide number value. .

On the other hand, in the dark, if the subject is sufficiently close, for example at about 2 meters, L = 6 as shown in Figure 4.
At 0 mm, the probability of red eye occurrence is about 10%, and even if you use the built-in flash, there are many cases where red eye does not occur. Since there is a deviation (balarax) between the light distribution angles of the flash and the external flash, uneven light distribution occurs when both flashes are used. Therefore, in this case, it is better to turn off the external flash and control the built-in flash to emit light, since uneven light distribution is less likely to occur and it is advantageous in terms of energy conservation. In addition, in FIG. 5, as the distance between the built-in flash and the external flash becomes short, the influence thereof increases, and uneven light distribution is more likely to occur.

The present invention has been made in consideration of each of the above-mentioned shooting conditions, and when an external flash is attached, various shooting information (subject distance,
By selecting the appropriate combination of both built-in and external flashes based on the lens focal length, subject brightness, and whether the photograph is backlit, it is possible to take appropriate photographs without causing red-eye phenomenon, while also reducing energy consumption. The purpose is to provide a camera with a built-in flash that is efficient.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a camera with a built-in flash that can be freely attached with an external flash, and has the following features: a detection means for detecting whether the external flash is attached, and a control means for selecting a light emission combination of both the built-in flash and the external flash and controlling the light emission based on the photographing information obtained from the detection means when the external flash is attached. Equipped with:

Further, a storage means stores predetermined subject information including at least conditions that cause a red-eye phenomenon, and this subject information is compared with photographic information obtained from the detection means to determine whether at least a red-eye phenomenon occurs. The image forming apparatus may include a determining means and a warning means for issuing a warning when the determining means determines that a red eye phenomenon will occur.

In addition, both the built-in and external flashes are fired when the subject is backlit, and only the built-in flash is fired when the subject is close or in the macro area. When this happens, you can fire both the built-in and external flashes.

[Function] According to the above configuration, when taking a picture with an external flash attached, both the built-in flash and the external flash Select an appropriate flash combination. Further, according to the invention of claim 2, when it is determined that the detected information matches predetermined stored information such as conditions that cause a red eye phenomenon, a warning display to that effect is displayed. For example, the subject can be sufficiently illuminated when backlit or at low brightness, and uneven light distribution will not occur when the subject is close.

[Embodiment] An embodiment of a camera with a built-in flash according to the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a front view when an external flash 2 is attached to a camera 1 equipped with a built-in flash 3.
represents the distance between the lens optical axis and the light emitting part of the built-in flash 3, and L2 represents the distance between the lens optical axis and the light emitting part of the external flash 2, with the relationship L,2>Ll. As shown in FIG. 4, the shorter the distance ML (Ll, L2), the higher the probability of red eye occurrence from a short shooting distance.

FIG. 2 shows a block diagram of the flash emission control circuit. As a control means, a microcomputer (hereinafter referred to as
It has 4 microcontrollers (referred to as microcontrollers).

This microcomputer 4 has a built-in memory as a storage means, and the memory contains information such as subject distance, lens focal length, subject brightness, backlighting, etc.
Subject information for determining whether a red eye phenomenon occurs is input in advance. Further, signals from respective detection means such as a subject distance detection sensor 5, a lens focal length detection sensor 6, a subject brightness detection sensor 7, and a backlight detection sensor 8 are inputted to the microcomputer 4. Furthermore, as other input means, a photometry/distance measurement switch Sl, a release switch S2
, an external flash mounting detection switch S3, and a built-in flash activation switch S4 for setting the built-in flash 3 to automatic light emission mode are provided.

At the output end of the microcomputer 4, an AND circuit 10. An external flash 2 and a built-in flash 3 are connected via an AND circuit 11, and a light emitting diode D1. Similarly, a light emitting diode D flashes to display a red eye warning.
2 is provided. Note that the AND circuit 10. When the output of the AND circuit 11 becomes high level, each flash emits light. Further, an exposure control circuit 9 is connected to the microcomputer 4 to control exposure during photographing.

Next, the control procedure will be explained with reference to the flowcharts of FIGS. 3(a) and 3(b). First, when the photometry/distance measurement switch S1 is turned on (step #10), the subject distance, lens focal length, and subject brightness are determined.

Each photographic information as to whether or not it is backlit is sent to the sensor 5,
6 and 7.8 are input to the microcomputer 4 (#20). Based on this information, the microcomputer 4 determines whether the brightness is low (#30). If the brightness is low, the built-in flash activation switch S4 is activated. It is determined whether the automatic flash mode is set (#40). If the automatic flash mode is set, it is determined based on the photographic information whether the red eye phenomenon is occurring (#50). If it is not in automatic flash mode,
The microcomputer 4 uses the diode D1 to display a recommendation to use the flash (#60), and the AND circuit 10 and the AND
The output of the circuit 11 is set to a low level (hereinafter referred to as rLo J), and the inputs of the external flash 2 and built-in flash 3 are set to "Lo"(#70).

If it is determined in #50 that a red-eye phenomenon occurs, it is determined whether the external flash 2 is connected (#80). If the external flash 2 is connected, AND circuit 10 is rHiJ, AND circuit 1
1 as "LO", and each input of external flash 2 and built-in flash 3 as rHi, , rLoJ (#110)
That is, only the external flash 2 is made to emit light, thereby preventing the red-eye phenomenon from occurring.

In addition, if the external flash 2 is not connected at #80, a red eye occurrence warning is displayed at diode D2 (#120), and the process proceeds to #100. Also, at #50, the state in which red eye phenomenon occurs If not, determine whether external flash 2 is connected (
#130).

If it is connected, please determine whether it is a macro area.#
90), if it is a macro area, set the AND circuit 10 to "Lo"
, AND circuit 11 is set to high level (r)! i'), and the inputs of the external flash 2 and built-in flash 3 are rLo' and rHi, respectively (#100).
. In other words, in the macro range, red-eye phenomenon is less likely to occur and the subject can be illuminated sufficiently with only the second flash, so in the macro range, only the built-in flash 3 is fired to prevent uneven light distribution. If not, both the AND circuit 10 and the AND circuit 11 are set to "r Hl",
Both external flash 2 and built-in flash 3 inputs are set to “H”.
1” (#140). That is, in this case, it is determined that the red-eye phenomenon is unlikely to occur, so by emitting both flashes, a larger amount of light is obtained. If the external flash 2 is not connected at #130, the process advances to #100.

On the other hand, if it is determined in #30 that the brightness is not low, it is determined whether it is backlit (#150), and if it is backlit, it is determined whether or not it is in automatic light emission mode (#160).

In the case of automatic flash mode, determine whether external flash 2 is connected (#170). If it is connected, proceed to #90, determine whether it is in the macro area, and check the result. Proceed to #100 or #140 accordingly.

External fludge, if L2 is not connected, #10
If the automatic light emission mode is not set at #160, the diode D1 displays a recommendation to use a flash (#180), and the process advances to #70. If it is determined at #150 that there is no backlight, the process proceeds to #70.

Above #70. #100. #110. After #140, the microcomputer 4 takes the next step to release the release switch S2.
is ON (#190). When the release switch S2 is ON, the exposure control circuit 9 is activated to perform exposure (#200), and the display is turned OFF (#220).
), the operation ends (#230). If the switch S2 is not turned on, the photometry/distance measurement switch S1 is turned on.
The switch S1 is turned OFF when the photographer interrupts shooting, and at this time, the display is turned OFF (#220). >, the operation ends (#230). Also,
If the photometry/distance measurement switch S1 is not OFF in #210, return to #190 and switch S2 is ON, #J
L< is #190 until switch S1 is turned OFF. #2
Continue with the judgment in step 10.

In this way, by controlling the light emission of both the built-in and external flash 2.3 based on each shooting information, the subject is sufficiently illuminated, unnecessary flash is prevented, and red-eye phenomenon is prevented. It is possible to take pictures in a controlled and appropriate manner.

Next, a modification of the above embodiment will be described.

That is, if there is a difference between the light distribution characteristics of the external flash and the light distribution characteristics of the built-in flash, unnatural shadows may appear if both are emitted.

In order to prevent this, step #140 in FIG. 3(b) is omitted.

That is, in step #90 of the above embodiment, if it is determined that the area is not in the macro area, the process proceeds to step #110, and only the external flash is caused to emit light. This allows the built-in flash to fire in macro areas where red-eye is less likely to occur, and in other cases, only the external flash to fire, making it possible to more reliably prevent red-eye from occurring, and to prevent red-eye from occurring in advance. If it is known that a phenomenon is likely to occur, a warning can be issued to that effect.

[Effects of the Invention] As described above, according to the present invention, when an external flash is attached to a camera with a built-in flash and flash photography is performed,
Since the appropriate combination of light emission from both the built-in and external flashes is selected based on the various detected shooting information, the appropriate amount of light can always be irradiated on the subject, and flash photography is energy efficient. becomes possible.

More specifically, if you use an external flash, there is usually enough light, and because the light emitting part is far from the optical axis of the lens, red-eye phenomenon is less likely to occur. In this case, the built-in flash was considered inoperative. On the other hand, in the invention according to claims 2 and 3, for example, when the light is backlit and the brightness is relatively bright and it is considered that the pupils are not widely dilated,
Fires not only the external flash but also the built-in flash,
This allows you to take photos with sufficient illumination of the subject without causing red-eye effects.Also, when the subject is close up or when taking macro shots, red-eye effects are less likely to occur, so only the built-in flash fires. It is possible to prevent uneven light distribution and also to prevent wasteful energy consumption.

[Brief explanation of drawings]

Fig. 1 is a front view of a camera with a built-in flash according to an embodiment of the present invention equipped with an external flash, Fig. 2 is a circuit block diagram thereof, and Figs. 3 (a) and (b) are flowcharts showing its control procedure. , Figure 4 is a diagram showing the relationship between the distance between the lens optical axis and the light emitting part and the probability of red eye occurrence, and Figure 5 is a diagram showing the deviation (parallax) in the light distribution angle between the built-in flash and the external flash. be. l... Camera with built-in flash, 2... External flash, 3... Built-in flash, 4... Microcomputer, 5... Subject distance detection sensor, 6... Lens focal length detection sensor, 7 ...Subject brightness detection sensor, 8...Backlight detection sensor, Dl...Flash use recommendation display light emitting diode, D2...Red eye occurrence warning display light emitting diode, S3...External flash detection switch, S4.・Built-in flash activation switch. Figure 1

Claims (3)

[Claims] (1) In a camera with a built-in flash that can be freely attached to an external flash, there is a detection means that detects the focal length of the photographic lens, the distance to the subject, the brightness of the subject, and whether there is backlight, and when the external flash is attached, A camera with a built-in flash, comprising a control means for selecting a light emission combination of both built-in and external flashes and controlling light emission based on photographic information obtained from the detection means. (2) A storage means that stores predetermined subject information including at least conditions that cause the red-eye phenomenon, and compares this subject information with the photographic information obtained from the detection means, and determines whether at least the red-eye phenomenon occurs. 2. The camera with a built-in flash according to claim 1, further comprising: a determining means for determining whether a red-eye phenomenon occurs; and a warning means for issuing a warning when the determining means determines that a red-eye phenomenon will occur. (3) When the subject is backlit, both the built-in and external flashes are fired, and when the subject distance is close or in the macro area, only the built-in flash is fired, and it is judged that the brightness is low and red-eye phenomenon is unlikely to occur. 3. The camera with a built-in flash according to claim 1, wherein both the built-in and external flashes are made to emit light when the flash is activated.