JPS59204012A - Auto focus camera - Google Patents

Abstract

PURPOSE:To reduce a blur amount of an image by providing at least two positioning mechanisms whose lens set position in different from each other, and selecting one positioning mechanism in accordance with a photographing condition. CONSTITUTION:In case of an EE photographing by a program shutter device, when the focus of a photographing distance lens 9 measured by a distance measuring device 37 is matched, the electric conduction of an electromagnet 34 is stopped, a detaining pawl 23 is rotated counterclockwise by an energizing force of a spring 33, and it is engaged to the pawl of a ratchet gear 22. As a result, the rotation of a gear 16 stops, and the movement of a movable lens barrel 10 stops. When photographing by a stroboscope, a solenoid 24 is electrified, therefore, a plunger 25 moves in the left direction, and a ratchet gear 21 faces the detaining pawl 23. In this case, as for the ratchet gear 21 and 22, the position of the pawl is different, therefore, in the EE photographing and the stroboscope photographing, a photographic lens 9 can be positioned by a different step.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an autofocus camera that changes the set position of a lens depending on photographing conditions.

35. Most compact cameras have a built-in distance measuring device, which starts extending the taking lens by pressing the release button, and stops moving the photographing lens in stages according to the shooting distance detected by the distance measuring device. It is designed to be positioned accurately. This positioning is performed by a ratchet gear that moves in conjunction with the photographic lens, an electromagnet that is activated by a signal from the distance measuring device, and a locking pawl that locks onto the ratchet gear by this electromagnet.

The set position (stop position) of the lens is determined with consideration to the depth of field, and is often set in about 4 to 6 levels. However, does the depth of field depend on the aperture and aperture?
1. In low-brightness conditions, the aperture becomes wider (the bokeh area of the d1 image becomes thicker. <-Z, L1 diameter τ is changed (Flashmatic +, 5%) Many of the shots are downward.With this camera, at close distances where Fujinosch and ticks work, the aperture aperture changes depending on the shooting distance. Since you become a small woman, you can get a clear image 7. However,
When the brightness is as low as 1 IEV, which is covered by the film latitude, the aperture is wide open at a distance where the Frason Umatic does not work, so as mentioned above, the amount of blur in the image is very small4).

It is an object of the present invention to solve the above-mentioned drawbacks, and provides at least two sets of positioning mechanisms, each with a different lens set position. The device is characterized in that one of the positioning mechanisms is selected and used depending on the body brightness.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of an EE mechanism according to the present invention.

FIG. 2 is a front view of an autofocus camera with an ivy.

On the front of the camera body 1 is a lens section 2. Strobe light emitting section 31 finder 4. Rangefinder window 5 and 6° Release point 7
．． A strobe switch 8 is installed. When the strobe switch 8 is set to the ON position, the strobe light emitting section 3 emits light in synchronization with the shutter device as usual. Note that the strobe light emitting unit 3 may be configured to automatically emit light when the subject brightness is low. The lens section 2 is
It consists of a movable lens barrel 10 that holds a photographic lens 9, and a fixed lens barrel 11 that holds this movable lens barrel 10 in a movable manner.

FIG. 2 shows the main part of the present invention. The above-mentioned possible 1jJ
The eJ cylinder JO is biased to the right by a spring 14, and the pin 15 provided on the 6" sharp @10 is pressed against the 1---- provided on the gear 16.
The bar is in contact with the bar part 17. As shown in FIG. 3, the pin 15 is pushed by the taper portion 17, and the setting position of the movable lens barrel 10 is determined by the slit 12.

61'' Gear 16 is used for film winding as is well known)! r'+j: Force is applied to set the charge position, and the lock is released in conjunction with the upward movement of the release button 8. When this lock is removed, the bottle 15 is rotated by the stored force of No. 19 (~, and the bottle 15 is displaced according to the rotating scene
,.

i1! The IMM gear 16 meshes with the gear 20 and rotates together with the gear I6. This gear 2oVC, claw I
Two ratchet gears 21 and 22 with different Ii are turned +
It is set in November. These ratchet gears 2
A locking pawl 23 is provided so as to be secured to either one of 1.22. Said gear 20, Lateets I gear 21
and 22 are fixed to the plunger 25 of the solenoid 24. In the illustrated state, the ratchet gear 2 is attached to the locking pawl 23.
2 are facing each other, and the locking pawl 23 can be displaced and engaged with the ratchet gear 22. When the coil 26 is energized, the plunger 25 moves to the left, so that the ratchet gear 21 faces the locking pawl 21. This coil 2G
is connected in series with the switch 28 and the battery 29, and is interlocked with the strobe switch 8 so that it is activated when the switch 28 is closed.

FIG. 4 shows the positioning mechanism, and the locking claw 2
3 is rotatably supported by a shaft 82, and is supported by a spring 8.
3, it is biased counterclockwise.

At one end of the locking pawl 23, there is an armature 36 that runs along the iron core 35 of the TL magnet 34. 'It is.

A coil 88 of the electromagnet 34 is energized by a signal from the distance measuring device 37 .

Next, the operation of the above embodiment will be explained. In EE photography in which exposure is program-controlled according to the subject brightness, the solenoid 24 is not fully energized. When the gear 16 rotates, the movable lens barrel 1o is coupled with the taper portion 17 and the pin 15.
moves in the direction of the optical axis. While the movable lens barrel 10 is moving,
Since the electromagnet 34 is energized, the locking pawl 28 remains stationary at the position shown in FIG. 4. As is well known, the distance measuring device 3
When the photographing lens 9 is focused on the photographing distance measured in step 7, ? ii: Since the magnet 34 is de-energized, the spring 3
The locking pawl 23 is rotated counterclockwise by the force of No. 3 and engages with the pawl of the ratchet gear 22.

As a result, the gear 16 stops rotating, and the movable lens barrel 1
0 shift L) 1 force stops. In this way, there are many professional Munyasota devices 1L! ;l! During photographing, the photographing lens 9 is positioned by the ratchet gear 22 and the locking pawl 28.

At the time of photo shooting, the solenoid 24 is energized, so the plunger 25 moves to the left, and the cylindrical gear 21 faces the locking pawl 23.

Here, since the positions of the claws of the grippers 21 and 22 are different, the photographic lens 9 can be positioned in different steps for J'2E photography and strobe photography.

FIG. 5 shows an example of a program diagram of a block/ram shutter device having a flashmatic function. At proper exposure, the aperture is kept at 1"2.8 at LV9 or lower, and only the shutter speed is accelerated, and at LV9 or higher, the circular direction of the aperture and 7.yata speed changes.

The relationship between the lens set position and the circle of least confusion when using the programmunyanta device that performs the exposure shown in FIG. Table 1 shows the lens position during EE photography and strobe photography.At a crystal brightness of 0, the aperture is adjusted by the programmed shutter device fi'c. Since the f/3.5 is obtained, it is possible to keep the j/circle of confusion δ within 0.05 as shown by the solid line. In LV 9, the aperture is set to 1''2.8 by the programmed shutter device 1''1-, so the maximum value of the circle of least confusion δ is approximately 0.065, as shown by the dotted line.

Shi/kokate 1. The blur of the image becomes sharp in the darkest shadow for E] at low brightness, and it is difficult to obtain a clear image. At low brightness, 1: '> to 1...] Shooting and rotating the camera in 1 hour (71, λ, 4 shadows, the 1: '> to 1...)・The tick mechanism changes the aperture according to the shooting distance, so at about 8 m'l, the minimum sardine dispersion can be kept within about 0.05. However, at about 3 to 4 m ( /,)
At range and at infinity (I N F ), the circle of least confusion δ〃
- Since it is approximately 0.06, the blur of the image will be 1゛G for a person.

On the other hand, in the above-mentioned embodiment, when LV 9 or higher is reached, a flash warning message is displayed, so when switching to strobe photography, the lens is set in EE photography and a bottom slump. Therefore, even in the case of LV9, the circle of least confusion δ can be kept within about 0.05, as shown by the two-dot chain line. Note that it is convenient to have the strobe automatically emit light when the level is below LV9.

In the above embodiment, strobe photography is performed at L■9 or lower, but the following describes a case where the camera does not have a strobe and is configured to perform J5 photography even at low brightness. Explain.

This also applies to cameras that use mate strobes that do not have a flashmatic mechanism. 6th
As explained in the figure, since 1y is blurred when the brightness is low, it is necessary to change the lens set position by moving C5 to a high 14 degree or low walking power.

Figure 7 shows an example in which the solenoid is energized when the subject brightness is low.The EE right camera, which uses a 1-program shutter device, has a certain value of subject brightness as shown in Figure 5. In the above case, the aperture aperture and shutter speed change in a block manner, and below a certain value, the aperture becomes open, and the shutter speed changes. Therefore, when the aperture is wide open, the depth of field η becomes shallow, and the amount of image blur increases.

When the switch 40 is turned on lf+, the light receiving element 41 and t
+j: The voltage of the battery 43 is applied to the A-resistor 42, and a voltage corresponding to 11 degrees is generated at the connection A' and Ir-1144.

When tt+El- of ( exceeds a certain level, transistor 45 becomes
do.

(/ζ- Once upon a time, the coil 26 was advanced at low brightness 1,
・4.・, 11.1 is not traced in the north.

7i) Using the Grogram Yack device shown in Ri 1￥1, the lens center when lens set i and 711 white rBi are determined depending on whether the brightness is tX:rr y, It' degrees or low brightness. Rank 16- and J1 elementary school ■iXl!
The 1V=j relationship with the iL circle is shown in FIG. Here, Table 2 shows the relationship between the subject cover and the lens set position.

In addition, in the case of "C(/,)人しょう", the lens set is 1 white or 01 friend 1 station when it is low.

In Fig. 8, as shown by the two-dot chain line, in EE photography at low brightness below LV9, the lens flap is different from that in EE photography at high brightness, so the minimum circle of confusion is It is possible to become pregnant within (δ) of 0.05. Furthermore, I Nl! (At about 100 m1, the circle of least confusion becomes large, but since most of the time at low brightness is strobe photography, there is no practical problem.

Note that the present invention may be divided into three types: stropho photography, still brightness EE photography, and low brightness EE photography, and the lenses may be set at different positions for each type. In this case, three ratchet gears may be arranged in parallel, and two solenoids may be provided to move the shafts containing these ratchet gears in two force directions.

The present invention, which has a hole configuration, changes the lens center position depending on whether the strobe is used or not, or depending on the brightness information of the subject, so it is possible to take clear images with a small amount of glare. can.

[Brief explanation of the drawing]

FIG. 1 is a front view of an autofocus camera implementing the present invention. FIG. 2 is a sectional view showing essential parts of the present invention. FIG. 3 is a sectional view of a portion of the taper. FIG. 4 is a front view of the positioning arrangement. FIG. 5 is a program diagram of the program shunter device. FIG. 6 shows the lens center position 1i'1' in an embodiment in which the lens set position is changed depending on the use or inconvenience of strobe light:
FIG. 7, which is a rough diagram showing the relationship between the distance and the circle of least confusion, is a circuit diagram showing an embodiment in which a solenoid is energized according to the brightness of the subject. FIG. 8 is a graph showing the relationship between the lens set position and the circle of least confusion in an embodiment in which the lens set position is changed depending on the subject brightness. 8... Strobe light emitting part 5, 6... Distance measuring window 9.
... Seme shadow lens IO ... sharp tube 15 ・
・ ・ Bin 17 ・ ・ ・
Taper part 21. 22... Ratchet gear 23... Locking pawl 24... Solenoid 26.
... Coil 41 ... Light receiving element. 3 (Figure 7

Claims (1)

[Scope of Claims] (1, J. An autofocus camera that positions a photographic lens in stages according to a photographing distance detected by a distance measuring device, at least two sets of positioning that make the stopping positions of the photographic lens different. An autofocus camera characterized by being provided with a mechanism. (2) A patent characterized in that one of the two sets of positioning mechanisms is selectively used depending on the use condition of the strobe! The autofocus camera according to item 1. (, 3) The two sets of positioning mechanisms select one of the two sets of positioning mechanisms depending on whether the subject brightness is lower than a predetermined value.
An autofocus camera according to claim i1, characterized in that it does not shift. (4) The T'4'J M positioning mechanism includes a ratchet gear that rotates in conjunction with the movement of the photographic lens, and a lock that engages with the pawl of the ratchet gear in conjunction with the distance measuring device. An autofocus camera according to any one of claims 1 to 3, characterized in that the camera comprises a claw. (5) Two of the ratchet gears are provided on a shaft that is moved by an lenoid, and the ratchet gear facing the locking pawl is switched depending on the energization state of the lenoid. The autofocus camera according to any one of items 3 to 3.