JP2011113010A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera providing an excellent picked-up image in flash photographing, without being affected by variation of the traveling speeds of a shutter. <P>SOLUTION: The camera (1) is equipped with: a shutter part (23) which has a front curtain and a rear curtain traveling with a time difference so as to open and close a photographic picture frame (4) and at least a slit (120) formed outside the photographic picture frame area of the front curtain; a slit detection means (80) which detects timing when the slit passes through a detection reference position (5), when the front curtain travels; and a traveling speed calculation means (90) which calculates the traveling speed of the front curtain, on the basis of the timing when the slit passes through the detection reference position, detected by the slit detection means and the opening interval of the slit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a camera having a focal plane shutter.

  In general, in flash photography with a camera equipped with a focal plane shutter (hereinafter referred to as shutter), after the shutter front curtain opens the entire area of the photography screen, a light emission signal is output to the light emitting device to emit flash light. Yes. The flash light emission is stopped before the rear curtain of the shutter shields the photographing screen.

  With respect to the flash light emission timing as described above, a detecting means for detecting the leading edge of the front curtain of the shutter is provided, and after a certain delay time has elapsed from the time when the leading edge of the front curtain is detected by this detecting means, A system that emits flash light on the assumption that the entire area is open has been proposed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-15052

  The traveling speed of the front curtain and the rear curtain of the shutter varies depending on the use environment as well as individual differences and aging of each shutter. For this reason, even when the leading edge of the front curtain is detected as in the conventional example, it is difficult to emit flash light at a predetermined timing due to variations in traveling speed.

  If the running speed varies as described above, the front curtain of the shutter may emit flash light before opening the entire area of the shooting screen. In this case, since the flash light is blocked by the portion covered by the curtain, uneven exposure occurs. Therefore, it is necessary to add a certain grace time (margin) in consideration of the variation in the running speed of the shutter curtain between the detection of the leading edge of the front curtain and the output of the light emission signal.

  However, if the minimum shutter speed (synchronization time) that can be tuned to the flash emission is increased with a sufficient grace period between the detection of the leading edge of the front curtain and the flash light emission, the flash light Is blocked by the rear curtain of the shutter, and exposure unevenness may occur. Therefore, the synchronization speed cannot be increased with the grace time set in consideration of variations in the travel speed of the shutter curtain.

  An object of the present invention is to provide a camera that can obtain a good captured image in flash photography without being affected by variations in the travel speed of the shutter.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention according to claim 1 has a front curtain and a rear curtain that run with a time difference so as to open and close the shooting screen (4), and at least a slit (120) is formed outside the shooting screen area of the front curtain. A shutter part (23), slit detection means (80) for detecting the timing when the slit passes the detection reference position (5) when the front curtain travels, and the slit detected by the slit detection means A camera (1) comprising: a traveling speed calculation means (90) for calculating a traveling speed of the front curtain based on a timing when the detection reference position is passed and an opening interval of the slit. .
The invention according to claim 2 is the camera (1) according to claim 1, wherein the front curtain detects the detection based on the traveling speed of the front curtain calculated by the traveling speed calculation means (90). A predicted time calculating means (90) for calculating a predicted time from the passage of the reference position (5) until the entire area of the shooting screen (4) is opened; and after the leading curtain has passed the detection reference position. And a shutter release notification means (90) for outputting a shutter release signal after the predicted time has elapsed.
The invention according to claim 3 is the camera (1) according to claim 2, wherein the shutter opening signal output from the shutter opening notification means (90) is a light emitting device (70) provided in the camera. ) Is a light emission control signal for emitting light.
The invention according to claim 4 is the camera (1) according to any one of claims 1 to 3, wherein the front curtain and the rear curtain are each composed of a plurality of shutter blades, and the slit (120) is formed on the shutter blade (101) that starts traveling first in the front curtain.
The invention according to claim 5 is the camera (1) according to any one of claims 1 to 4, wherein the detection reference position (5) is the travel of the front curtain on the shooting screen (4). It is characterized by being provided approximately in the middle of the direction.
Note that the configuration described with reference numerals may be modified as appropriate, and at least a part of the configuration may be replaced with another component.

  ADVANTAGE OF THE INVENTION According to this invention, the camera which can obtain a favorable picked-up image in flash imaging | photography can be provided, without being influenced by the variation in the running speed of a shutter.

It is a block diagram which shows the structure of the camera concerning embodiment. (A), (b) is a block diagram of a shutter unit and a slit detection part. (A), (b) is a block diagram of a shutter unit and a slit detection part. It is a timing chart which shows the change of each signal and a state at the time of flash photography. It is a flowchart which shows the process sequence of the camera control part at the time of flash imaging | photography.

  Hereinafter, embodiments of a camera according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the camera 1 according to this embodiment. As shown in FIG. 1, the camera 1 of this embodiment includes an imaging unit 10, a lens / mechanism unit 20, a release switch 30, an operation input unit 40, a memory 50, a liquid crystal monitor 60, a light emitting unit 70, a slit detection unit 80, This is a digital camera provided with a camera control unit 90.

  The imaging unit 10 includes an imaging element 11 and an image processing unit 12. The image pickup device 11 is a light-electricity conversion device that converts subject light that has passed through the photographing lens 21 of the lens / mechanism unit 20 into an electric signal and outputs the electric signal. The electrical signal output from the image sensor 11 is subjected to analog processing and digital processing such as noise removal, A / D conversion, color correction processing, size change, and encoding in the image processing unit 12, and camera control unit as image data 90.

  The lens / mechanism unit 20 includes a photographing lens 21, an aperture unit 22, a shutter unit 23, and a drive control unit 24. The subject light incident on the photographic lens 21 is guided to the imaging element 11 of the imaging unit 10 through the aperture unit 22 opened to the size of the aperture value and the shutter unit 23 opened at a predetermined exposure time. The aperture unit 22 adjusts the amount of subject light, and includes a plurality of aperture blades (not shown). The shutter unit 23 is for adjusting the exposure time of the subject light, and includes a plurality of shutter blades described later. The drive control unit 24 includes, for example, an actuator that drives the photographing lens 21 in the optical axis direction for focus adjustment, an actuator that drives the aperture unit 22 and the shutter unit 23, and the like.

  The release switch 30 is a part that is operated when a photographer who is a user inputs a shooting instruction to the camera control unit 90. The release switch 30 can be operated in two stages, a half-press operation and a full-press operation. When the photographer performs a half-press operation on the release button, a shooting preparation signal is transmitted to the camera control unit 90. Thereby, the camera control unit 90 automatically performs focusing (focusing) on a main subject based on an output of a distance measuring sensor (not shown), and based on an output of a photometric sensor (not shown). AE (automatic exposure) control that automatically adjusts the exposure is performed. Then, when the photographer fully presses the release button, a shooting start signal is transmitted to the camera control unit 90. Thereby, the aperture unit 22 and the shutter unit 23 are driven at a predetermined timing, and the subject light is imaged by the imaging unit 10. At the time of flash photography, the camera control unit 90 controls the light emission control signal output to the light emitting unit 70.

  The operation input unit 40 is a part that is operated when the photographer inputs various instructions to the camera control unit 90, and includes a switch, a dial, a lever, and the like (not shown). For example, a power switch (not shown) is turned on / off by a photographer pressing the power switch.

  The memory 50 is composed of an EEPROM, a ROM, a DRAM, or the like. The EEPROM is a non-volatile memory that retains stored information even when the camera 1 is turned off, and stores setting information input by the photographer. The ROM is a memory that stores programs necessary for the operation and control of the camera 1 as well as initial values and setting values necessary for executing the programs. The DRAM is a volatile memory in which stored information is erased when the power of the camera 1 is turned off. The image data output from the imaging unit 10, the image processing unit 12, the camera control unit 90, and the like are stored in the DRAM. Data used when performing arithmetic processing is temporarily stored.

  Although not shown, the camera 1 is loaded with a memory card that records captured images and their data. This memory card is detachably attached to a card slot (not shown) of the camera 1. The camera 1 is provided with a recording device (not shown) for writing data to the memory card.

  The liquid crystal monitor 60 includes a liquid crystal display, and displays captured images and playback images, moving images including a live view, various menu screens, shooting conditions such as a shutter speed and an aperture value, and the like.

  The light emitting unit 70 is a light emitting device that emits flash light to a subject by a built-in flash (not shown) provided in front of the camera 1 (or an external flash attached to an accessory shoe (not shown)). The light emitting unit 70 emits light when the light emission control signal output from the camera control unit 90 changes from the L (Low) level to the H (High) level.

  The slit detector 80 detects the timing at which a later-described slit formed in the front curtain blade passes a predetermined detection reference position when a front-curtain blade, which will be described later, of the shutter unit 23 travels. The edge detection signal is output. The configuration of the slit detector 80 will be described in detail later.

  The camera control unit 90 is an integrated circuit that controls the above-described camera 1 in an integrated manner, and includes a microprocessor including a CPU. The camera control unit 90 calculates a lens driving amount for focus adjustment based on an output of a distance measuring sensor (not shown), transfers this to the driving control unit 24, and either an in-lens motor or an in-body motor (whichever The focus adjustment of the photographic lens 21 is also controlled. In addition, an appropriate exposure control value is calculated based on the output of a photometric sensor (not shown), and this exposure control value is transferred to the drive control unit 24 to control exposure adjustment by the aperture unit 22 and the shutter unit 23. . At the same time, the imaging of the subject light in the imaging unit 10 is controlled. Furthermore, the camera control unit 90 controls the light emission amount of the light emitting unit 70 during flash photography. In addition, the camera control unit 90 includes a timer (not shown) that performs time counting.

  The camera control unit 90 functions as a traveling speed calculation unit that calculates a traveling speed of a leading blade that will be described later, based on an edge detection signal output from the slit detection unit 80 and an opening interval of a slit (not shown). In addition, the camera control unit 90 performs a period from when the front curtain blade passes the detection reference position until the entire shooting screen is opened based on the travel speed of the front curtain blade calculated by the function as the travel speed calculation unit. It functions as a predicted time calculation means for calculating the predicted time. Further, the camera control unit 90 opens the shutter by setting the light emission control signal (shutter release signal) output to the light emitting unit 70 to H level after the predicted time has elapsed after the leading blade has passed the detection reference position. It functions as a notification means.

  Next, the configuration of the shutter unit 23 and the slit detector 80 will be described. 2 and 3 are configuration diagrams of the shutter unit 23 and the slit detection unit 80. FIG. 2 and 3, (a) is a front view when the shutter unit 23 is viewed from the image sensor 11 side, and (b) is a cross-sectional view taken along the line II of (a). 2 shows a state before photographing in which the shutter unit 23 shields the photographing screen, and FIG. 3 shows a state at the time of photographing in which the front curtain of the shutter unit 23 starts running (in FIG. 3, one is shown). (Parts are omitted.)

  Here, the structure of the shutter unit 23 and the slit detection part 80 is demonstrated using FIG. However, also in FIG. 3, the same parts as those in FIG.

  The shutter unit 23 includes a front curtain unit 100, a rear curtain unit 200, and an actuator unit (not shown). Among these, the front curtain unit 100 and the rear curtain unit 200 are attached to one surface of the shutter substrate 2, and the actuator unit (not shown) is attached to the side edge of the shutter substrate 2. A cover plate 3 is attached to the shutter substrate 2 so as to cover the shutter unit 23.

  The front curtain unit 100 includes front curtain blades 101, 102, 103, and 104. The front curtain blades 101 to 104 are connected to a front curtain drive mechanism 110 including a plurality of front curtain drive arms and a plurality of front curtain blade support pins (all of which are omitted from the reference numerals). Further, the rear curtain unit 200 includes rear curtain blades 201, 202, 203, and 204. The rear curtain blades 201 to 204 are connected to a rear curtain drive mechanism 210 including a plurality of front curtain drive arms and a plurality of front curtain blade support pins (all of which are omitted from the reference numerals).

  The shutter unit 23 of the present embodiment is configured as a vertical plane focal plane shutter. In the state before photographing, as shown in FIG. 2, the leading blades 101 to 104 of the leading curtain unit 100 are expanded upward to cover the photographing screen 4. On the other hand, the rear curtain blades 201 to 204 of the rear curtain unit 200 are housed on the shooting screen 4 in an overlapping state. At the time of shooting, as shown in FIG. 3A, the leading blades 101 to 104 of the leading curtain unit 100 start to travel in the direction of arrow II, and the shooting screen 4 is gradually opened from top to bottom. . Then, when the front curtain blades 101 to 104 of the front curtain unit 100 are stored in a state where they overlap the lower part of the shooting screen 4, the entire area of the shooting screen 4 is opened. At the time of flash photography, flash light is emitted from the light emitting unit 70 at this timing, and at the same time, subject light is imaged by the imaging unit 10.

  Then, the rear curtain blades 201 to 204 of the rear curtain unit 200 begin to travel in the direction of arrow II in the drawing with a predetermined time (exposure time) difference, and the photographing screen 4 is gradually shielded from the top to the bottom. When the rear curtain blades 201 to 204 of the rear curtain unit 200 are expanded downward to cover the photographing screen 4, the entire area of the photographing screen 4 is shielded. Thereafter, the front curtain blades 101 to 104 of the front curtain unit 100 travel in the direction of arrow III in FIG. 3A to cover the photographing screen 4, and the rear curtain blades 201 to 204 of the rear curtain unit 200 are also shown in the same figure. The vehicle travels in the direction of arrow III and is stored on the photographing screen 4. Thereby, as shown in FIG. 2A, the state before photographing is restored.

  Among the front curtain blades 101 to 104 of the front curtain unit 100 described above, a slit 120 is formed in the front curtain blade 101 that starts traveling first. The slit 120 is an opening for detecting the timing when the leading blade 101 passes a detection reference position, which will be described later, and is formed outside the area of the photographing screen 4. In this embodiment, as shown in FIG. 3A, the upper and lower opening ends of the slit 120 of the leading blade 101 are referred to as a first edge 121 and a second edge 122, respectively, and the side edge of the leading blade 101 is This is referred to as the third edge 123. In addition, the slit 120 has an opening interval X (m) in the vertical direction of the photographing screen 4 as shown in FIG.

  Next, the slit detector 80 will be described. The slit detection unit 80 includes a photo reflector 81 disposed on the back surface of the shutter substrate 2 and a reflection plate 84 disposed on the shutter substrate 2 side of the cover plate 3. An opening 5 is formed in the shutter substrate 2. The position of the opening 5 is outside the area of the shooting screen 4 and is in the middle of the vertical direction of the shooting screen 4 (the traveling direction of the leading blade 101), and this position becomes the detection reference position of the slit 120. As shown in FIG. 3B, the interval from the opening 5 (detection reference position) to the lower end of the shooting screen 4 is defined as Y (m). In the present embodiment, as shown in FIG. 3A, the position of the first edge 121 at the position where the center of the opening 5 and the center of the slit 120 overlap is used as the detection reference position. Any position may be used as the detection reference position.

  The photo reflector 81 includes a light emitting element 82 that emits beam-shaped infrared light, and a light receiving element 83 that receives the infrared light reflected by the reflecting plate 84. As shown in FIG. 3B, the photo reflector 81 and the reflecting plate 84 are attached at positions facing each other with the opening 5 interposed therebetween. Further, when the infrared light is irradiated from the light emitting element 82 of the photo reflector 81, the infrared light is reflected by the reflecting plate 84 and received by the light receiving element 83 of the photo reflector 81. The mounting angle of the light receiving element 83 is set.

  In the slit detection unit 80 of the present embodiment, when the infrared light is not received by the light receiving element 83 of the photo reflector 81, the edge detection signal output to the camera control unit 90 is set to H (High) level, and the photo reflector 81 is set. In the state where infrared light is received by the light receiving element 83, the edge detection signal output to the camera control unit 90 is set to L (Low) level. The relationship between the H level and L level of the edge detection signal may be reversed.

  In the above configuration, when the leading blade 101 travels from the position of FIG. 2 in the direction of arrow II and the first edge 121 of the leading blade 101 first reaches the opening 5 (detection reference position), the light emitting element 82 Since the irradiated infrared light is reflected by the reflection plate 84 and received by the light receiving element 83, the edge detection signal output from the slit detection unit 80 is at the L level. Next, when the second edge 122 of the leading blade 101 reaches the opening 5, the infrared light emitted from the light emitting element 82 is blocked by the leading blade 101, so that the edge detection output from the slit detector 80 is detected. The signal becomes H level. Further, when the third edge 123 of the leading blade 101 reaches the opening 5, the infrared light irradiated from the light emitting element 82 is reflected by the reflecting plate 84 and received by the light receiving element 83. For this reason, the edge detection signal output from the slit detection part 80 becomes L level. Thereafter, while the photographing screen 4 is open throughout, the edge detection signal output from the slit detection unit 80 is maintained at the L level.

  FIG. 4 is a timing chart showing changes in signals and states during flash photography, and the horizontal axis shows time. The front curtain / rear curtain travel curve shown in FIG. 4 represents a travel curve 41 of the front curtain blades 101 to 104 and a travel curve 42 of the rear curtain blades 201 to 204. In the front-curtain / rear-curtain travel curve, the vertical axis indicates the vertical positions of the shooting screen 4 of the front-curtain blades 101 to 104 and the rear-curtain blades 201 to 204. FIG. 4 shows a case of flash photography at a shutter speed that is lower than the flash synchronization speed.

  When flash shooting is started, the leading blades 101 to 104 start to travel downward in order, and the shooting screen 4 is gradually opened from top to bottom. When the first edge 121 of the leading blade 101 reaches the opening 5 (detection reference position) formed in the middle of the shooting screen 4 in the vertical direction, the infrared light emitted from the light emitting element 82 is reflected by the reflector 84. Therefore, the edge detection signal output from the slit detector 80 is at L level. Subsequently, when the second edge 122 of the leading blade 101 reaches the opening 5, the infrared light emitted from the light emitting element 82 is blocked by the leading blade 101, so that the edge detection output from the slit detector 80 is detected. The signal becomes H level.

  Next, the camera control unit 90 calculates the traveling speed of the leading blade 101 based on the edge detection signal output from the slit detection unit 80 and the opening interval X (m) of the slit 120. The camera control unit 90 starts timing by the timer when the edge detection signal changes from H to L level, and then stops timing by the timer when the edge detection signal changes from L to H level. Thereby, the time interval t1 (s) when the edge detection signal changes from L to H level can be obtained. Since the opening interval X of the slit 120 described above is known, the running speed V (m / s) of the leading blade 101 can be calculated by the equation of the opening interval X (m) / time interval t1 (s). .

  Next, on the basis of the calculated traveling speed V of the front curtain blade 101, the camera control unit 90 passes through the detection reference position until the front curtain blade 101 opens the entire area of the shooting screen 4, that is, the front curtain blade. A predicted time t2 until 101 reaches the lower part of the shooting screen 4 is calculated. As shown in FIG. 3B, the interval Y from the opening 5 (detection reference position) to the lower end of the shooting screen 4 is known, so the interval Y (m) / the traveling speed V (m of the leading blade 101 / S), the predicted time t2 (s) until the leading blade 101 reaches the lower part of the photographing screen 4 can be calculated.

  Subsequently, when the third edge 123 of the leading blade 101 reaches the opening 5, the infrared light irradiated from the light emitting element 82 is reflected by the reflecting plate 84 and received by the light receiving element 83. The edge detection signal output from 80 again becomes L level. The camera control unit 90 starts timing by a timer when the edge detection signal changes from H to L level. Then, when the previously calculated predicted time t2 elapses, the time measurement by the timer is stopped, and the light emission control signal output to the light emitting unit 70 is set to the H level. At this time, the camera control unit 90 sets the light emission control signal to the H level after the elapse of the minimum grace period t3 after the elapse of the prediction time t2.

  However, the grace time t3 may be added to the above-described prediction time t2. In this case, immediately after the predicted time t2 has elapsed, the light emission control signal output to the light emitting unit 70 is set to the H level.

  As shown in FIG. 4, when the camera control unit 90 sets the light emission control signal to the H level, the light emitting unit 70 emits flash light at the timing when the entire area of the photographing screen 4 is opened (screen is fully opened). .

  Next, the processing procedure of the camera control unit 90 at the time of flash photography will be described with reference to the flowchart of FIG. This flash photography processing routine is executed by pressing the release switch 30 during flash photography.

  First, in step S101, the camera control unit 90 determines whether or not the first edge 121 of the leading blade 101 has been detected at the detection reference position. If this determination is YES, in step S102, the camera control unit 90 starts timing by a timer. Subsequently, in step S103, the camera control unit 90 determines whether or not the second edge 122 of the leading blade 101 has been detected in the opening 5 (detection reference position). If YES in this determination, in step S104, the camera control unit 90 stops / clears the time measurement by the timer. In step S <b> 105, the camera control unit 90 calculates the traveling speed V of the leading blade 101. Subsequently, in step S <b> 106, the camera control unit 90 calculates an estimated time t <b> 2 until the leading blade 101 reaches the lower side of the shooting screen 4.

  Next, in step S107, the camera control unit 90 determines whether the third edge 123 of the leading blade 101 has been detected. If this determination is YES, in step S108, the camera control unit 90 starts timing by a timer. Subsequently, in step S109, the camera control unit 90 determines whether or not the predicted time t2 has elapsed by counting the timer. If YES in this determination, in step S110, the camera control unit 90 sets the light emission control signal output to the light emitting unit 70 to the H level. In step S111, the camera control unit 90 stops / clears the time measurement by the timer, and ends the processing by this routine.

According to embodiment mentioned above, there exist the following effects.
(1) The traveling speed of the front curtain blade 101 is calculated for each shutter release, and based on this traveling speed, the time until the front curtain blade 101 opens the entire shooting screen is calculated to emit flash light. Therefore, even if the shutter travel speed varies, it is possible to minimize the delay time from when the release switch 30 is pressed until the light emitting unit 70 emits flash light. Therefore, the flash light is not blocked by the rear curtain of the shutter, causing uneven exposure, and the synchronization speed can be increased, and a good captured image can always be obtained.
(2) Of the front curtain blades 101 to 104, the front curtain blade 101 that starts traveling first is away from the front curtain drive arm and the center of rotation, and thus position fluctuations and rattling of parts are likely to occur. . In the present embodiment, since the slit 120 is formed in the leading blade 101, the travel speed of the shutter is calculated under the condition that the influence of the position variation, the backlash of parts, etc. is the greatest. For this reason, it is possible to control the flash light in a state in which the influence of variation for each product is most considered.
(3) Since the detection reference position is set in the middle of the shooting screen 4 in the vertical direction (traveling direction of the leading blade 101), the traveling speed V can be calculated in a period during which traveling of the leading blade 101 is relatively stable. it can. In addition, after the second edge 122 of the slit 120 is detected, sufficient time can be secured for calculating the traveling speed V and the predicted time t2.
(Deformation)

Without being limited to the embodiment described above, the present invention can be variously modified and changed as described below, and these are also within the scope of the present invention.
(1) Although the example in which the slit 120 is formed in the leading blade 101 has been described, the present invention is not limited to this, and may be formed in other leading blades 102 to 104.
(2) The example in which the opening 5 serving as the detection reference position of the slit 120 is formed outside the area of the shooting screen 4 and in the middle of the shooting screen 4 in the vertical direction is shown. As long as it is outside the region, it may be formed at any position.
(3) In the photo reflector 81, the light receiving element 83 may be disposed at the position of the reflecting plate 84, and the light emitting element 82 and the light receiving element 83 may be disposed to face each other with the opening 5 interposed therebetween. With such a configuration, the reflector 84 can be omitted. In addition, unnecessary reflection or reflection of light by the reflector 84 can be prevented. Further, as long as the first edge 121 to the third edge 123 can be detected when the slit 120 passes through the opening 5, not only the photo reflector 81 but also other elements may be used, or a combination thereof. Can also be used.
(4) The traveling speed of the leading blade 101 calculated when the slit 120 passes through the opening 5 may be used for correcting the shutter speed. That is, by storing the set shutter speed and the shutter speed calculated at the time of actual operation in the memory 50, the error can be automatically corrected or utilized as maintenance data. Can do.
(5) In this embodiment, the digital camera provided with the image sensor 11 has been described as an example, but the present invention can also be applied to a film-type camera.

  Moreover, although the said embodiment and modification can be used in combination suitably, since the structure of each embodiment is clear by illustration and description, detailed description is abbreviate | omitted. Furthermore, the present invention is not limited by the embodiment described above.

  1: camera, 4: shooting screen, 5: aperture, 10: imaging unit, 20: lens / mechanism unit, 30: release switch, 50: memory, 70: light emitting unit, 80: slit detection unit, 90: camera control Part, 101-104: front curtain blade, 120: slit

Claims (5)

A shutter part having a front curtain and a rear curtain that run at a time difference so as to open and close the shooting screen, and at least a shutter part formed with a slit outside the shooting screen area of the front curtain;
Slit detecting means for detecting a timing at which the slit passes a detection reference position when the front curtain travels;
Travel speed calculating means for calculating the travel speed of the front curtain based on the timing when the slit detected by the slit detection means passes the detection reference position and the opening interval of the slit;
A camera comprising: The camera according to claim 1,
Based on the travel speed of the front curtain calculated by the travel speed calculation means, a predicted time calculation for calculating a predicted time from when the front curtain passes the detection reference position until the entire area of the shooting screen is opened. Means,
And a shutter release notification means for outputting a shutter release signal after the predicted time has elapsed after the front curtain passes the detection reference position. The camera according to claim 2,
The camera, wherein the shutter opening signal output from the shutter opening notification means is a light emission control signal for causing a light emitting device provided in the camera to emit light. The camera according to any one of claims 1 to 3,
The front curtain and the rear curtain are each composed of a plurality of shutter blades,
2. The camera according to claim 1, wherein the slit is formed in a shutter blade that starts traveling first in the front curtain. The camera according to any one of claims 1 to 4,
The camera according to claim 1, wherein the detection reference position is provided approximately in the middle of the traveling direction of the front curtain on the shooting screen.

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