JPH0572602A - Camera provided with second blind synchronizing controller - Google Patents

Abstract

PURPOSE:To execute effective second blind synchronizing flash photographing by setting such second blind synchronism that a switching means is turned on so as to finish the emission of flash light just before a second blind starts to shut off an image plane regardless of the size of the image plane. CONSTITUTION:A synchronizing speed control means 11 is provided with a first and second blinds synchronizing delay time selection means 13, an X contact delay time selection means 14 which selects an X contact delay time in accordance with the size of the image plane from the set of delay time selected by the means 13, and a delay time setting means 15 which sets the delay time selected by the means 14. Then, in the case of second blind synchronism, the switching means is turned on so as to finish the emission of flash light just before the second blind starts to shut off the image plane in accordance with the size of the image plane. Thus, the effective second blind synchronizing flash photographing is executed regardless of the size of the image plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera equipped with a flash rear curtain synchronization control device, and more particularly to a rear curtain synchronization control device for a camera capable of rear curtain synchronization and screen size switching.

[0002]

2. Description of the Related Art As a single-lens reflex camera,
It is known that a flash tuning device that automatically switches the shutter speed to the flash tuning shutter speed when in a flash firing mode for flash firing is known. Here, the flash synchronization shutter speed is set so that the shutter is fully opened for a certain time or more from the start of flash emission to the end of flash emission.

The conventional flash tuning device is a front curtain synchronization (first curtain synchronization). That is, when the front curtain completely opens the screen, the switch means (X contact) is turned on and the flash is emitted.

On the other hand, in recent years, a rear curtain synchronizing (rear curtain synchronizing) means for emitting a flash just before the shutter is closed has been developed. FIG. 7 shows the relationship between the travel of the shutter and the screen when the rear curtain is synchronized.

In FIG. 9, the vertical axis represents the vertical direction of the screen and the horizontal axis represents time. In the figure, reference numeral 51 is a trailing edge portion of the front curtain, reference numeral 53 is a traveling locus of the leading edge portion of the rear curtain,
That is, it represents a running characteristic curve. Reference numerals 61 and 63 respectively represent the positions of the upper side and the lower side of the normal photographing screen (full size). In this figure, the leading curtain running characteristic curve 5
The area sandwiched between 1 and the trailing curtain running characteristic curve 53 is the open area of the shooting screen. Here, the shutter speed T _A, when the fully opened time and T _C, on the X contact to the standard delay time from the travel start time t of the front curtain TD _A after the time t _X1 (the flash), the fully open time T It can be seen that the rear curtain starts blocking the standard screen at time t ₄ after _C (after the flash emission ends).

By the way, in recent years, in addition to shooting with a normal screen size, for example, a camera capable of switching the screen size to a panoramic size in which the vertical size of the screen is reduced to obtain a panoramic effect has been developed. FIG. 9 shows the upper side 65 and the lower side 67 of the panoramic screen. As is apparent from this figure, when performing curtain tuning after conventional when panoramic screen, after full opening time T _C lapse Panorama screen (t ₅ -
It can be seen that it is fully opened during t ₄ ). Therefore, the rear curtain synchronization effect is lost in the rear curtain synchronization flash photography on the panorama screen.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a camera capable of changing the screen size and having a rear curtain synchronization control device capable of effective rear curtain synchronization flash photography.

[0008]

SUMMARY OF THE INVENTION The present invention has been made paying attention to the fact that when the screen size is reduced in the shutter traveling direction, the time when the rear curtain starts closing the screen is delayed.
The present invention made based on this point of view includes a focal plane shutter, a switch unit for emitting a flash, a screen size switching unit for switching a shooting screen size between a standard screen size and at least a size in the shutter curtain traveling direction, and the switching. Synchronization control means for changing the on-timing of the switch means so that the flash emission ends immediately before the rear curtain of the shutter starts closing the screen according to the screen size. It is characterized by

According to this structure, when the rear curtain is synchronized,
Depending on the screen size, the switch means is turned on so that the flash emission will end immediately before the trailing curtain starts blocking the screen, so effective trailing curtain synchronized flash shooting is possible regardless of the shooting screen size become.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. FIG. 1 shows a screen size switching means and a front curtain according to the present invention.
Of the embodiment applied to the camera equipped with the rear curtain synchronization selection means,
7 is a graph for explaining operation characteristics when the rear curtain is synchronized. In this graph, reference numerals 61 and 63 indicate the positions of the upper side and the lower side of the normal screen, and the broken lines between them indicate the upper side 65 and the lower side 67 of the panoramic screen, respectively. Reference numeral 51 is a running characteristic curve of the trailing edge of the front curtain, and reference numeral 53 is a running characteristic curve of the leading edge of the trailing curtain.
The part sandwiched between 1 and 53 is the shutter open part.

When the screen is switched to the standard screen, when the rear curtain starts closing the standard screen, the light emission end criterion is used before the opening time T _C , that is, the standard delay time TD ₁ from the running start time t of the front curtain. A flash is emitted at a later time t _X1 . As a result, the fully open time T _C from the flash emission
After the lapse of time (time t _{4 when the} trailing curtain running characteristic curve 53 crosses the upper side 61), the trailing curtain starts blocking the standard screen. Here, the shutter speed T _1, the time when the front curtain begins to open the standard screen (time front curtain traveling curve 51 crosses the upper side 61) t _0, when the shutter fully opened time and T _C, the delay time TD ₁ is calculated by TD ₁ = T ₁ −T _C + (t ₀ −t).

When the screen is switched to the panorama screen, when the trailing curtain starts closing the panorama screen, the end reference time is before the opening time T _C , that is, from the time t after the running start time of the front curtain to the panorama delay time TD ₂ The flash is _fired at time t _X2 when the time has elapsed. As a result, the rear curtain starts to Saegi閉of the panorama screen when fully open time T _C elapsed (time t _5). Assuming that the shutter speed is T ₁ and the time when the front curtain starts opening the panorama screen (the time when the front curtain running characteristic curve 51 crosses the panorama upper side 65) is t ₁ , TD ₂
= T ₁ −T _C + (t ₁ −t).

FIG. 2 is a graph showing the operating characteristics when the front curtain is synchronized, and the same members as those in FIG. 1 are designated by the same reference numerals. As is clear from this figure, when the standard screen is displayed,
After a delay from t when the first curtain starts traveling time TD _A, i.e. the front curtain and the flash is emitted fully open time t _XA standard screen _(when the front curtain traveling characteristic curve 51 has a cross and the lower side 63) ing. When a panoramic screen, after the delay time TD _B from the front curtain traveling start time t, that is _(when the front curtain traveling characteristic curve 51 has a cross and the lower side 67 of the panoramic picture) time t _XB front curtain is fully opened panoramic screen The flash is fired. Here, the shutter speed T _A is
T _A ≧ TD _A + T _C − (t ₀ −t) is satisfied.

The shutter speed T ₁ at the time of rear curtain synchronization is also T
_{1 ≧ TD A + T C -} (t 0 -t) must be satisfied, second-curtain synchronization effect, the shutter speed _{T 1} is is emphasized _{slower, T 1> TD A + T} C - (t 0 -T) is preferred.

Next, the configuration of the embodiment of the flash tuning control device capable of switching the flash tuning speed between the normal tuning speed T _A and the panorama tuning speed T _B will be described with reference to FIG.
And it demonstrates with reference to FIG. Tuning speed control means 11
Is an X contact that selects an X contact delay time corresponding to the screen size from the set of the front curtain / rear curtain synchronization delay time selection means 13 and the delay time selected by the front curtain / rear curtain synchronization delay time selection means 13. The delay time selecting means 14 and the delay time setting means 15 for setting the delay time selected by the X-contact delay time selecting means 14 are provided.

The front curtain / rear curtain synchronization delay time selecting means 13 is
One set of memory means 1 in which the standard screen delay time TD _A and the panorama screen delay time TD _B for front curtain synchronization are respectively memorized
6, 17 and the standard delay time TD ₁ and the panorama delay time TD ₂ for the rear curtain synchronization, the delay time stored in either one of the memory means 18 and 19 is stored as the first curtain and the second curtain. It is selected according to the selection made by the curtain synchronization selecting means 20. The X contact delay time selecting means 14 is switched by the screen size switching means 21 from the delay time TD _A , TD _B or the delay time TD ₁ , TD _{2 of} the set selected by the front curtain / rear curtain synchronizing delay time selecting means 13. Select one delay time corresponding to the standard size or panorama size specified. The delay time selected by the X-contact delay time selecting means 14 is set in the delay time setting means 15.
The delay time set in the delay time setting means 15 is
It is read from the exposure control means 31 at the time of shooting in the flash emission mode and used as the X-contact delay time.

This camera is also capable of performing calculations related to exposure,
Exposure control means 31 that executes control, shutter front curtain 33 and shutter rear curtain 35 that form a focal plane shutter, drivers 37 and 39 that control the driving of these shutter curtains 33 and 35, and delay time measurement The timer 40, the X contact 41, and the light emission control device 43 for causing the flash 45 to emit light are provided. Although the camera is normally equipped with a taking lens, an aperture, a photometric device, a release button, a film winding mechanism, etc., they are omitted because they are not necessary for understanding the present invention.

This shutter device is a vertically traveling type focal plane shutter, and the shutter curtains 33 and 35 travel vertically. Also, the shutter curtains 33 and 35 are
At the time of release, it is driven by a shutter charge spring (not shown). The shutter charge spring is charged in association with the film winding and is locked by a mechanical locking means (not shown). This mechanical lock is released by the drivers 37 and 39 according to the set shutter speed at the time of release, whereby the elastic restoring force of the charge spring causes the shutter curtains 33 and 35 to be released.
Runs. The timer 40 measures the time from when the front curtain 33 is released. Then, the exposure control means 31 sets the timer 40 to the set delay times TD ₁ , TD ₂ , TD _A , and TD _B.
The X contact 41 is turned on when is measured. As a result, the light emission control circuit 43 causes the flash 45 to emit light.

FIG. 5 shows the screen size switching means 21.
An embodiment is shown in which the upper and lower parts of the photographing screen are covered with a light shield.

Aperture frame 2 for controlling the full size screen
A pair of light shielding plates 204 and 205, which are longer than the width of the aperture frame 203, are disposed outside the upper and lower sides of 03. One end of each of the pair of shading plates 204 and 205 is slidably guided by a guide plate 206 extending in the lateral direction of the screen. A pair of nuts 207 and 208 having a reverse thread are fixed to the other ends of the light shielding plates 204 and 205. These nuts 207, 208 are screwed to the reverse threaded portions 209a, 209b of the shaft 209 provided in parallel with the other short sides of the aperture frame 203, in accordance with the external rule of the other short sides. Therefore, the shading plates 204 and 205 are
When the shaft 209 rotates, the shaft 209 moves in parallel in the panorama size forming direction approaching each other or in the normal screen forming direction separating from each other according to the rotating direction.

Further, the shaft 209 has a reduction gear mechanism 21.
It is rotationally driven by a motor 213 via 0, 211 and 212. The motor 213 is driven by the drive control circuit 215 in response to the switching operation of the screen size changeover switch 214, and drives the light shielding plates 204 and 205 to the standard screen size position or the panorama size position. In the panorama size position, the light shielding plates 204 and 205 regulate the upper side and the lower side of the panorama size screen by these edge portions 204a and 205b. Further, the limit switches 216 and 217 detect that the light shielding plates 204 and 205 have reached the standard screen size position or the panorama size position, and the drive control circuit 215 is stopped by this detection.

The delay time selecting operation in this embodiment is as shown in the flow chart of FIG. First, the first curtain. If the leading curtain tuning is selected by the trailing curtain tuning selecting means 20, the delay times TD _A and TD _B related to the leading curtain tuning are set as the leading curtain.
It is selected by the rear curtain synchronization delay time selection means 13, and if the rear curtain synchronization is selected, the delay times TD ₁ and TD ₂ are set to the first curtain.
It is selected by the rear curtain synchronization delay time selection means 13. Then, the set of delay times selected by 13 (TD _A , TD
_B or TD ₁ , TD ₂ ), the standard delay time TD _A or TD when the screen is switched to the standard screen
_1, the delay time when it is switched to the panoramic screen TD _B or TD ₂ is X contact delay time selection means 14
Selected by. Then, the X contact delay time selecting means 1
One delay time selected by 4 is set in the delay time setting means 15.

[0023] In the case when the second curtain tunable changes shutter speed, open time _{T C,} the time _(t 0 -t) and the time _(t 1 -t) Since the constant, these values The delay time TD ₁ and TD ₂ are measured and stored in advance, and the delay times TD ₁ and TD ₂ are obtained from these values and the set shutter speed T ₁ .

Although the flash tuning control means 11 and the exposure control means 31 have been described as separate members in the illustrated embodiment, they can be configured by the same microcomputer.

As described above, in the present embodiment, the timing for emitting the flash is changed in accordance with the screen size in the rear curtain synchronization. That is, when the screen has a panoramic size that is reduced in the traveling direction of the shutter as compared with the standard size, the on timing of the X contact is delayed according to the time when the rear curtain starts blocking the panoramic screen.
Even in panorama size, an effective rear curtain synchronization effect can be obtained.

In the above description of the present embodiment, the camera provided with the mechanical screen size changing means for covering the photographing screen with the light shielding plate has been described, but the present invention is not limited to this. For example, when panoramic shooting is selected, the screen size is not mechanically restricted at the time of shooting, and at the time of film winding, a pair of light sources 71 arranged above and below the film F exposes the upper and lower parts of the film F to expose the panoramic screen. Is formed (see FIG. 7) or an identification mark 74 for identifying panoramic photography is exposed on the film by the light source 73, and the identification mark 74 is detected during printing to print in a panoramic size. (See FIG. 8).

The present invention can also be applied to a half-size camera which can change the size of the photographing screen in the running direction of the shutter curtain. The change of the shooting screen size is not limited to the panoramic size, and in short, any change of the size of the shutter curtain in the traveling direction can be applied.

[0028]

As described above, according to the present invention, regardless of the screen size, since the trailing curtain is synchronized so that the switch means is turned on so that the flash emission is finished immediately before the trailing curtain starts to shield the screen, the screen size is changed. Despite this, effective rear-curtain synchronized flash photography is possible.

[Brief description of drawings]

FIG. 1 is a graph illustrating a trailing curtain tuning operation of an embodiment of a flash tuning control device of the present invention.

FIG. 2 is a graph illustrating a front curtain tuning operation of the same embodiment.

FIG. 3 is a block diagram showing a main part of the flash synchronization speed switching device.

FIG. 4 is a diagram showing a main part of an exposure device of a camera to which the flash synchronization speed switching device is applied.

FIG. 5 is a diagram showing a configuration of an example of a screen size switching unit of the camera.

FIG. 6 is a flowchart showing a switching operation of the flash synchronization speed switching device.

FIG. 7 is a diagram showing a state of a film when panoramic shooting is performed by another screen size switching unit.

FIG. 8 is a diagram showing a state of a film when panoramic shooting is performed by another screen size switching unit.

FIG. 9 is a graph illustrating a conventional rear curtain synchronization operation.

[Explanation of symbols]

 11 Tuning Speed Control Means 13 First Curtain / Second Curtain Tuning Delay Time Selecting Means 14 Delay Time Selecting Means 15 Delay Time Setting Means 20 First Curtain / Second Curtain Tuning Selecting Means 21 Screen Size Switching Means

Claims (3)

[Claims] 1. A focal plane shutter, a switch means for emitting a flash light, a screen size switching means for switching a screen size of the shutter curtain in a traveling direction, and a rear curtain of the shutter according to the switched screen size. Is equipped with a tuning control means for changing the on-timing of the switch means so that the flash emission ends immediately before the screen is closed, and the trailing curtain tuning control device is provided. camera. 2. The camera according to claim 1, wherein the tuning control means includes a trailing curtain tuning control device that turns on the switch means when a predetermined delay time elapses after the shutter front curtain starts running. 3. The synchronization control means according to claim 1 or 2, wherein the front curtain synchronization for turning on the switch means is set as a light emission start reference when the front curtain of the shutter fully opens the photographing screen, and for the shutter. Rear-curtain tuning control, characterized in that it includes front-curtain / rear-curtain tuning selection means for switching between the rear-curtain tuning in which the switch means is turned on when the trailing curtain starts blocking of the photographing screen and the light emission end reference. A camera equipped with a device.