JPH0650040U - Camera with built-in flash control circuit that can change screen size - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a camera with a built-in strobe control circuit, which can change the screen size so that the flash can be emitted when the size of the screen is restricted, even if the flash is prohibited when the screen is full size. [Arrangement] A camera having a screen size detection unit for detecting that the screen size has been switched to a full size screen or a regulated size screen smaller than the full size screen, and a stroboscopic light emitting unit, wherein the full size screen is On the other hand, the strobe adequacy determining means for determining whether or not the taking lens is suitable for strobe emission, and when the strobe adequacy determining means determines that the strobe adequacy is not appropriate, the screen size detecting means detects the full size screen. And a light emission control means for prohibiting the light emission of the strobe light emitting means and permitting the light emission of the strobe light emitting means when a restricted size screen is detected.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a camera capable of changing a shooting screen size and controlling flash emission.

[0002]

[Prior art and its problems]

 Some single-lens reflex cameras with a built-in strobe prohibit the built-in strobe from firing if the light emitted by the built-in strobe does not reach the entire shooting screen. For example, if the wide-angle side cover focal length of the strobe is equivalent to 35 mm, even if a lens with a focal length of 28 mm is attached, or if a zoom lens is attached and the focal length is zoomed to 28 mm, the strobe light is emitted. Since the strobe light does not reach the four corners of the shooting range, these four corners are underexposed. In other words, if you use a shooting lens that has a wider angle of view than the strobe can cover, you cannot illuminate the entire shooting screen. This is shown in FIG. 3 with reference numeral a and in FIG. 5 with reference numerals 42a, 42b, 42c and 42d in relation to the viewfinder field 41.

In addition, even if a lens barrel with a thick or long lens barrel such as a high-power zoom lens is attached, or even if the strobe can cover the four corners of the photographing screen during short-distance photographing, As shown in FIG. 3, the tip portion 30e of the lens barrel 30 interferes, and the portion marked with b in FIG. 3 is the lens barrel 30e as shown with 42e in FIG. Underexposure follows the shape of. Therefore, in conventional single-lens reflex cameras, when the above-mentioned strobe light cannot be radiated over the entire shooting screen, the built-in strobe is prohibited from firing.

However, when the shooting screen is switched from the normal full size screen to a regulation size screen smaller than this, for example, a panorama screen, as shown in FIG. 5, the four corners 42a, 42b, 42c of the shooting screen are displayed. The underexposed portions of 42d and the lower central portion 42e are located outside the panoramic screen. That is, as shown in FIG. 6, the dark portions 52a to 52e, which appear in the full-size print 51 and to which the strobe light does not reach, are located outside the exposure area in the panorama print 53 and do not appear on the panoramic print 53. It has been found.

[0005]

[The purpose of the device]

 An object of the present invention is to provide a camera with a built-in strobe control circuit capable of changing the screen size so that even if the stroboscopic light emission is prohibited during the full size screen, the stroboscopic light emission is possible during the regulated size screen.

[0006]

[Outline of the device]

 In order to achieve this object, the present invention provides a camera equipped with a screen size detecting means for detecting that the screen size has been switched to a full size screen or a regulated size screen smaller than the full size screen, and a strobe light emitting means. If the strobe suitability determining means determines whether or not the shooting lens is suitable for strobe emission for the full-size screen, and if the strobe suitability determining means is unsuitable, the above screen size detection is performed. And a light emission control means for permitting the strobe light emitting means to emit light when detecting the full-size screen, and for permitting the strobe light emitting means to emit light when detecting the restricted size screen. It has a feature.

[0007]

【Example】

 The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a block diagram showing the main configuration of an embodiment in which the present invention is applied to a single-lens reflex camera with a built-in flash. The single-lens reflex camera of this embodiment includes a camera body 10, a built-in strobe 20 that can be moved to a retracted position and a light emitting position of the camera body 10 by a moving mechanism (not shown), and a taking lens (zoom) that is detachable from the camera body 10. Lens) 30 and.

The main control circuit 11 mounted on the camera body 10 is a control means for controlling the operation of the entire camera, and in this embodiment, the lens control circuit 31 mounted on the photographing lens 30 controls the lens As the unique information, a function as a lens information input means for inputting the lens angle of view (current focal length) as the suitability information for the built-in flash, lens barrel vignetting information, subject distance information, aperture information, etc. It also has a function as a strobe suitability judging means for determining whether or not the built-in strobe 20 can emit light based on the applied lens information, and a function as a light emission control means for controlling the light emission of the built-in strobe 20 based on the judgment.

Further, the photometric circuit 13 receives the subject light incident through the taking lens 30 and outputs a subject brightness signal to the main control circuit 11. The main control circuit 11 calculates a shutter speed and an aperture value based on the subject brightness signal, and displays those values on the displays 15 and 17. Further, the main control circuit 11 displays the suitability of strobe light emission on the displays 15 and 17. FIG. 4 and FIG. 5 show the display device 17 provided in the viewfinder field. In the figure, reference numeral 17a indicates strobe light emission information, and 17b and 17c indicate shutter speed and aperture value, respectively. When the built-in strobe 20 emits light, the main control circuit 11 measures the amount of light reflected from the subject through the photometric circuit 13, and controls the built-in strobe 20 to stop emitting light based on the measured light amount. The built-in strobe 20 is driven to emit light by a light emitting circuit 21.

The built-in strobe 20 is movably held between a storage position and a light emitting (up) position by a known mechanism (not shown), and is constantly urged to move in the light emitting position direction until it reaches the storage position. Sometimes, it is locked in the storage position by a lock mechanism (not shown). Further, whether or not the built-in strobe 20 has moved to the up position is detected by the strobe position detection switch 23.

Although not shown in detail, the single-lens reflex camera of the present embodiment can switch the screen size from the full size screen to the panoramic size screen by mounting a known panorama adapter 18 on the aperture. The attachment / detachment of the panorama adapter 18 is detected by the main control circuit 11 via the screen size detection switch 19. Note that the present invention is not limited to a camera having an adapter attachment / detachment mechanism, but one having a mechanism for changing the shooting screen size, such as a mechanism for changing the screen size by moving the light shielding plate, or an optical shooting device. It can also be applied to cameras with a panorama mode that does not block the screen.

Next, the release process in the single-lens reflex camera of the present embodiment and the process associated therewith will be described with reference to the flowchart shown in FIG. This processing is controlled by the main control circuit 11 based on the program stored in the internal ROM of the main control circuit 11. The illustrated flow chart shows the parts necessary for understanding the present invention in order to explain the gist of the present invention.

The main control circuit 11 enters this main routine when the main power is turned on. Then, first, the lens control circuit 31 repeats the input of lens information including the built-in flash suitability information and the check of the photometric switch SWS to wait for the photometric switch SWS to be turned on (S11, S13). When the photometric switch SWS is turned on, the subject brightness signal is input from the photometric circuit 13 and the shutter speed and aperture value are calculated (S15). Then, it is checked via the strobe position detection switch 23 whether or not the built-in strobe 20 is in the light emitting position (S17).

When the built-in strobe 20 is not up, that is, when the built-in strobe 20 is not made to emit light, it waits until the release switch SWR is turned on (S17, S45). When the release switch SWR is turned on, the exposure process is performed without making the strobe emit light based on the shutter speed and the aperture value calculated in step S15, and when the exposure is completed, this routine is exited (S45, S47, S27). Then, on condition that the photometric switch SWS and the release switch SWR are turned off, this routine is entered again.

When the built-in flash 20 is up, whether or not the panorama adapter 18 is attached is checked via the screen size detection switch 19 (S17, S19). When the panorama adapter 18 is not attached, it is checked based on the lens information whether the lens angle of view (focal length) is within the proper range and whether there is vignetting due to the lens barrel (S19, S31, S33). If the lens angle of view is not within the proper range or if there is vignetting due to the lens barrel, the flash warning display (flashing of the display element 17a) and the prohibition of the external strobe emission are performed, and a release process is performed to prevent the strobe 20 from firing ( S31, S43, S45, S47, S27 or S31, S33, S43, S45, S47, S27).

When the lens angle of view is within the appropriate range and there is no vignetting due to the lens barrel, wait until the release switch SWR is turned on, and then start the exposure by the release process by the strobe program that requires strobe light emission. Then, the built-in strobe 20 is made to emit light to perform exposure, and the process exits from this main routine (S31 to S39, S27).

The above is the processing when the panorama adapter 18 is not attached, but the processing when the panorama adapter 18 is attached and the built-in flash 20 is up is as follows. This processing is characterized by causing the built-in strobe 20 and the external strobe to emit light when the external strobe is attached regardless of the type of the taking lens and the focal length.

When the built-in flash 20 is up and the panorama adapter 18 is attached, when the release switch SWR is turned on, the lens information (lens angle of view and lens barrel vignetting information) input in step S11 is entered. ), The release process is started based on the shutter speed and aperture value obtained by the strobe program, the built-in strobe 20 is made to emit light, and the exposure is completed before exiting this routine (S21, S23, S25, S27).

As described above, in the single-lens reflex camera, when the panorama adapter 18 is attached, the built-in strobe 20 can emit light regardless of whether or not the photographing lens is suitable for strobe light emission. Even if the flash of the built-in flash 20 is prohibited on the size screen, the flash shooting is possible on the panorama size screen, and the flash shooting without uneven illumination is possible on the panorama size screen.

As described above, in the present embodiment, when the panorama adapter 18 is attached, the flash of the built-in flash is uniformly permitted. However, the configuration that relaxes the light emission prohibition condition, for example, when the light emission prohibition focal length is less than 35 mm In this case, the composition may be such that the emission-prohibited focal length is 28 mm. In addition to the panorama size, the restricted screen size includes half size and high definition size.

[0021]

[Effect of device]

 As is clear from the above description, the present invention enables the flash to fire when switching to a restricted size screen that is smaller than the full size screen, even if the flash is prohibited because the flash is not suitable for the full size screen. When shooting on a regulated size screen, a wide range of focal lengths according to the regulated size screen and appropriate flash photography with the lens type are possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of an embodiment of a single-lens reflex camera with a built-in strobe to which the present invention is applied.

FIG. 2 is a flowchart regarding main operations during release of the same-eye reflex camera.

FIG. 3 is a diagram illustrating a relationship between a built-in flash light and a shooting range in the same-eye reflex camera.

FIG. 4 is a diagram showing a relationship between a full size screen and a panoramic size screen in a viewfinder field.

FIG. 5 is a diagram showing a strobe light irradiation state in a viewfinder field.

FIG. 6 is a diagram for comparing stroboscopic irradiation states on full-size and panoramic size print surfaces.

[Explanation of symbols]

 10 camera body 11 main control circuit 18 panorama adapter 19 screen size detection switch 20 built-in flash 21 light emitting circuit 23 strobe position detection switch 30 shooting lens 31 lens control circuit

Claims (2)

[Scope of utility model registration request] 1. A camera provided with a screen size detection unit for detecting that the screen size has been switched to a full size screen or a restricted size screen smaller than the full size screen, and a stroboscopic light emitting unit, wherein the full size If the flash appropriateness determining means for determining whether or not the taking lens is suitable for strobe emission with respect to the screen and the flash appropriateness determining means are not suitable,
A light emission control means for prohibiting the light emission of the strobe light emitting means when the screen size detecting means detects a full size screen, and permitting the light emission of the strobe light emitting means for detecting the restricted size screen. A camera with a built-in strobe control circuit whose screen size can be changed. 2. The camera according to claim 1, wherein the taking lens is attachable / detachable, and the strobe adequacy determining means determines the focal length information, the current subject distance information, or the lens barrel vignetting from the taking lens. A camera with a built-in strobe control circuit that can change the screen size by inputting information and determining the suitability.