JPS5898724A - Automatic focus detecting device of camera - Google Patents

Abstract

PURPOSE:To execute the adjustment easily and also with high accuracy, by providing an optical member for converting an optical path to an image pickup surface, and an automatic focus detecting element which receives the light whose optical path has been converted by said optical member, and is provided at a position equivalent to said image pickup surface, etc. CONSTITUTION:Onto a holding plate 14, a circuit substrate 15 is stuck and this circuit substrate 15 fixes an image sensor 6 and also connects its electrically. Also, compression springs 16a, 16b and 16c are reducedly provided between the holding plate 14 and a bottom plate 12a of a mirror box body 12, also to each of them, adjusting screws 17a, 17b and 17c are piercedly installed, and the image sensor 6 is fitted to a position equivalent to a film 5 by an adjusting means consisting of the adjusting screws 17a, 17b and 17c, etc. According to such constitution, the image sensor is capable of executing the adjusting easily and also with high accuracy by the three adjusting screws on the holding plate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic focus detection device for a camera equipped with an automatic focus detection element such as a self-scanning photoelectric element (hereinafter referred to as an image sensor); The present invention relates to an automatic focus detection device for a camera that is provided with adjustment means.

An image sensor has a row of photoelectric elements arranged at a position equivalent to the imaging surface of a lens system, and converts the light intensity distribution of the object into a time-series electrical signal using a scanning circuit corresponding to each row of photoelectric elements. . An automatic focus detection device is configured to automatically detect the focus of the lens system using the electrical output of the image sensor.

2. Description of the Related Art Conventionally, an automatic focus detection device is known that is applied to a single-lens reflex camera 1, for example, as shown in FIG. In the book, reference numeral 2 is a lens system, 3 and 4 are optical members that convert the optical path of the object light Lo, 3 is a semi-transparent mirror, and 4 is a total reflection mirror. The reflected light L1 whose optical path has been changed by the total reflection mirror 4 (2) is received by an image sensor 6 fixed at a position equivalent to the film 5 as an imaging surface. 8 is a focus plate that receives the reflected light L2 whose optical path has been changed by the semi-transparent mirror 3.The reflected light L2 that has passed through the focus plate 8 reaches the eyepiece 11 via a condenser lens 9 and a pentaprism 10. During exposure of the film 5, the semi-transparent mirror 3 and the total reflection mirror 4 are moved away from the optical path by a moving mechanism (not shown). Attached 1, this key box body 1
2 is attached to the camera housing 13. Furthermore, the image sensor 6 is connected to an electrical circuit (not shown) that processes its electrical output.

However, according to such an automatic focus detection device (=), since the image sensor 6 was fixed at a position equivalent to the film 5, for example, the key box main body 12 was
Even if a slight misalignment occurs when the device is attached to the device, there is no appropriate means for correcting it. Therefore, it is necessary to improve the manufacturing precision of the fixing member of the image sensor 6, and it takes time and effort to make adjustments during installation, resulting in poor workability and problems in terms of after-sales service for users.

This invention was made by focusing on such conventional problems, and includes an optical member that converts the optical path to the imaging surface;
By providing an automatic focus detection element that receives the light path converted by this optical member and is disposed at a position equivalent to the imaging surface, and an adjustment means to adjust the automatic focus detection element to the equivalent position, the above-mentioned The aim is to solve the problems that have arisen.

The present invention will be explained below based on the drawings. In addition, the same reference numerals are given to the constituent parts C that are the same as those of the conventional one, and redundant explanations will be omitted.

2 and 3 show the @1 embodiment of the invention. First, to explain the configuration, reference numeral 14 in the figure is a holding plate, and a circuit board 15 is fixed to ζ on this holding plate 14, and this circuit board 15 fixes and electrically connects the image sensor 6. ing.

The circuit board 15 has a pair of board ends 15m and 15b bent downward at a predetermined distance from a mount (not shown) (@II on the right in FIG. 2). Furthermore, the -@ (right side in Figure 83) of this circuit board 15 has an upwardly bent board end 15c.These board ends 15&.

15b and 15c are connected to an electric circuit that processes the electrical output of the image sensor 6.

Are the codes 16m, 16b, and 16c compression springs? These compression springs 16m, 16b, and 16c are compressed between the holding plate 14 and the bottom plate 12& of the key box main body 12, and two adjustment screws 17a, 17b, and 17c are inserted through them. .Of course, each adjustment screw 17 m, 17 b +
17c passes through the circuit board 15 and the holding plate 14, and is screwed onto the bottom plate 12&. That is, the holding plate 14 is capable of so-called three-point adjustment. In addition, there is a screw groove h1 for pot screw rotation on each head and tip of each adjustment screw 17a, 17b, and 17c. b2 t IIs・ti+t2
1 t, is formed.

A rising piece 12b is formed on the mount side of the bottom plate 12m of the key box body 12, and a cover 18 is formed on this rising piece 12b.
The apron 18& is attached through the tightening screw 19. Both sides of this cover 18 are fixed to the inner wall surfaces e and m2 on both sides of the key box main body 12.
19b is inserted and supported. Further, a hole 18b through which the reflected light L1 passes is formed at a position where the cover 18 faces the image sensor 6.

Note that the sign ratio is for the board ends 15m and 15b of the circuit board 15.
This hole is for extending the board end portion 15c above the key box body 12, and the hole is for extending the board end portion 15c to the side 1 of the key box body 12.

Next (Explain the two effects.

First, for example, when assembling a camera, the lens system 2
Attach a reference lens for adjustment.

This reference lens 6: allows the object light to pass through, and the reflected light L1 is received by the image sensor 6, and the focus is adjusted on the image sensor 6. If the focus is misaligned based on the electrical output information of the image sensor 6,
From below the key box body 12, insert an adjustment tool such as a screwdriver into the adjustment screw 17a.

Thread grooves at the tips of 17b and 17c jj r t2 +
Insert into t5 and adjust by screwing. As a result, the holding plate 14 moves in the vertical direction C in the figure, changing the angle of the image sensor 6 with respect to the reflected light L1 and the position in the optical path direction, thereby correcting the misalignment state.

Next ζ: In the so-called completed camera state where the key box main body 12 is attached to the camera housing 13, the thread groove 1+ at the tip.

Adjustment by t2 + t5 is generally impossible.

In this case, loosen the tightening screw 19 from the mount side and remove the cover 18. In this way, the adjustment screw 17
Thread groove h on each head of JL + 17 b r 17 c
+ Expose th2Hb5. Then, the above-mentioned moving mechanism is operated to retract the semi-transparent mirror 3 and the total reflection mirror 4. As a result, the adjusting screws 17a and 17b can be adjusted by inserting an adjusting tool from the aperture A side, and the adjusting screw 17c can be adjusted by inserting an adjusting tool from the mount side.

In this way, the image sensor 6 has the adjustment screw 17m,
The film 5 is adjusted by adjusting means consisting of 17b, 17'e, etc.
is aligned to the equivalent position.

4 to 8 show other embodiments of the adjusting means.

The second embodiment shown in Figure @4 has adjustment screws 17a, 17b, 17.
The vicinity of the head of c is screwed onto the retaining plate 14, and the tip thereof is inserted through the bottom plate 12m to form fludges 20a, 20b, 2.
0c to prevent it from being pulled out.

The other configurations are the same as those in the ml embodiment, so their explanation will be omitted.

In the third embodiment shown in FIG. The upper ends of the adjustment screws 17a, 17b, and 17c are in contact with each other, and each of the adjustment screws 17a, 17b, and 17c is screwed onto the bottom plate 12m.Also, since the bracket No. 18 is fixed, the adjustment screws 17a, 17b, and 17c are screwed to the bottom plate 12m. The apron 18a1, the rising piece 12b, etc. are omitted.The other configurations are the same as those of the first embodiment, so the explanation will be omitted.

The fourth embodiment shown in Fig. s6 includes compression springs 16a, 16b, 16
c is symmetrical with that of the third embodiment (two retaining plates 14 and a bottom plate 12m).
The upper ends of the adjustment screws 17m, 17b, and 17c are brought into contact with the cover 18, and the holes Pa +
Opening is formed in Pb r Pc and thread groove ti + i2
+ An adjustment tool is inserted into F.

The other configurations are the same as those in the third embodiment, so their explanation will be omitted.

The fifth embodiment shown in FIG. 7 has a compression spring 1 in the first embodiment.
6a, 16b, and 16c are omitted, and the circuit board 15 and the holding plate 14 are interposed between the heads of the adjustment screws 17a, 17b, and 17c and the flanges 21a + 21b + 21c, and the adjustment screw 17a.

The tips of 17b and 17c are screwed onto the bottom plate 12&C.

The other configurations are the same as in the first embodiment, so their explanation will be omitted.
Ru.

1J! In the sixth embodiment shown in FIG. 8, the bottom plate 12a of the lock box main body 12 is bent downward by two times at the end on the mount side, and a hole 18b' facing the image sensor 6 is formed in the bottom plate 12m.
The circuit board 15 and the holding plate 14 are placed below the circuit board 15 via compression springs 16a, 16b, and 16c.

Dry each compression spring 16m, 16b, 16c t: is the adjustment screw 17a.

17b, 17c are inserted through each screw 17a, 17b, 1
The tip of 7c is screwed onto the bottom plate 12a. The other configurations are the same as those in the ml embodiment, so their explanation will be omitted.

As explained above (=According to the present invention, there is an optical member that converts the optical path to the imaging surface, and an automatic focus detection element that receives the light whose optical path has been changed by this optical member and is disposed at a position equivalent to the imaging surface. and an adjusting means for aligning this automatic focus detection element to an equivalent position, so even if a slight positional deviation occurs in the image sensor during assembly or completion of the camera, it can be corrected immediately with a simple operation. There is no need to extremely increase the manufacturing accuracy of the image sensor fixing member, etc.

Further, each of the embodiments described above has the following effects in addition to the common effects described above.

First, in the first embodiment, the image sensor can be easily and precisely adjusted using three adjusting screws on the holding plate. Furthermore, since the thread grooves formed on both sides of each adjustment screw can be exposed to the inside and outside of the lockbox main body, adjustment can be made from the outside of the lockbox main body or the camera casing. Furthermore, the adjustment means can be mounted below the lock box body in a compact manner and can be covered with a cover, so it looks good and optical protection of the image sensor and the like can be achieved using the bracketed cover.

Next, in the second embodiment, by attaching a flange to the adjustment screw, firm attachment is possible.

Further, the third and fourth embodiments are useful when the adjustment screw can be adjusted only from below the lock box body. Useful when external exposure is not possible.

Furthermore, in the fifth embodiment, since the compression spring can be omitted, the number of parts and the number of installation steps can be reduced by one.

Furthermore, in the @6 embodiment, the space below the key box main body can be effectively used, and the cover can also be used as the bottom plate, making it extremely easy to attach the holding plate and the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a state in which a conventional autofocus detection element is attached to a single-lens reflex camera, and FIGS. 2 to 8 show each embodiment of the present invention. 1
The vertical cross-sectional view of the example, Figure $3 is the III-III cross-sectional view of Figure @2, Figures 4 to 8 are similar to Figure iJ2, and Figure 4 shows the flange attached to the adjustment screw. Fig. 5 is a sectional view showing a third embodiment in which the adjustment screw groove is formed only at one end, and Fig. 6 is a sectional view showing the third embodiment in which the adjustment screw is built into the key box body. Cross-sectional view showing an example, v
Figure J7 is a sectional view showing the fifth embodiment in which the compression spring is omitted;
FIG. 8 is a sectional view showing a sixth embodiment in which the cover also serves as the bottom plate. 5... Film (imaging surface), 6... Image sensor (automatic focus detection element), 17 a + 17 b +
17 c...Adjustment screw (Ill adjustment means). Applicant: Asahi Optical Industry Co., Ltd. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 (Pa)

Claims (1)

[Scope of Claims] ゛ An optical member that converts the optical path to the imaging surface; an automatic focus detection element that receives the light whose optical path has been changed by the optical member and is disposed at a position equivalent to the imaging surface; Align the automatic focus detection element to the equivalent position #JR
An automatic focus detection device for a camera, characterized in that it is equipped with an adjusting means.