JP3458390B2 - Video camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera which has an inner focus optical system and can be quickly fixed to a focus position by a simple operation.

[0002]

2. Description of the Related Art Conventionally, there is an inner focus optical system having an automatic focusing mechanism as a focusing function in a video camera. In this inner focus optical system, for example, the focus direction and the lens feed amount (relative value) are usually instructed to the microcomputer by operating a manual focus ring that rotates endlessly or a perspective button.

[0003]

In the case of the conventional inner focus method as described above, it is very difficult to instantly focus an absolute focus position, for example, a distance to a subject to macro, infinity or the like. Have difficulty.

In particular, in the inner focus, the amount of movement of the focus changes depending on the focal length, so that it is not possible to realize how many times the focus ring can be rotated in the above-mentioned endless manual focus ring, and therefore the manual focus ring is manually operated. It is technically very difficult to use the focus as with a single-lens reflex camera.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to obtain a video camera which can be quickly set to a predetermined focus position by rotating the quick focus operation section. And

[0006]

[SUMMARY OF] To achieve the above object, a video camera according to the present invention, a video camera having an inner focus optical system, the lens barrel of the optical system
Rotation on the front end side of the outer peripheral surface for fine adjustment focus operation
With a free manual focus ring,
Adjacent to the manual focus ring, a ring-shaped quill
Equipped with a focus control unit, the inner focus optical system is controlled by a microcomputer in conjunction with the dial operation of the quick focus control unit, and each focus position has a different focal length.
You can set the options selectively and instantly .
Setting the focus position in the ic focus operation section
After rotating the manual focus ring,
Therefore, the focus can be finely adjusted .

[0007]

The video camera according to the present invention constructed as described above.
Since a plurality of focus positions with different focal lengths are stored in the inner focus optical system in advance as data, the inner focus optical system is controlled by a microcomputer by dialing the quick focus operating section to select a desired focus position. The system is instantaneously controlled to move to a desired focus position, and then the manual focus ring is rotated to perform fine adjustment, so that the subject can be quickly focused.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view showing an example of an 8 mm video camera. In FIG. 1, reference numeral 1 is a camera body, 2 is an operation switch for switching a video camera between a camera (shooting) mode and a video mode, 3 is a viewfinder, and 4 is an inner focus optical system including a plurality of lens groups. By operating the operation switch 2 described above to the camera mode side, a focus operation can be performed by being driven by a command from a microcomputer (not shown).

The inner focus optical system 4 is provided with a rotatable manual focus ring 5 on its front end side.
A finely-adjusted focus operation can be performed by manually rotating the manual focus ring 5. Then, adjacent to the manual focus ring 5, the video of the present invention is attached.
The quick focus dial 6 of the quick focus device relating to the video camera is provided.

FIG. 2 shows a sectional view of a specific structure of the above-mentioned quick focus dial 6. The quick focus dial 6 is rotatably mounted around the lens barrel 7 in a click manner. As an example thereof, a ball 9 is held in a recess 7a formed in the lens barrel 7 with a spring 8 interposed, and the ball 9 is engaged with each recess 10 formed on the inner peripheral surface of the quick focus dial 6. By
The quick focus dial 6 is positioned at each of the recesses 10 engaged with the ball 9.

The quick focus dial 6 described above
Is configured to always return to the base position by, for example, a known shuttle ring mechanism (not shown) when the hand manually rotated is released. More specifically, by rotating the quick focus dial 6 to the right or left, the inner focus optical system 4 is driven by a command from the microcomputer, and the focus position is instantaneously changed from ∞ (infinity) to macro (Macro). Is equipped with a quick focus device that can be quickly operated.

A specific configuration of an example of the quick focus device will be described below. On the outer peripheral surface of the lens barrel 7 near the quick focus dial 6, as shown in FIG. 3, a mark 11 is displayed on the surface portion of the quick focus dial 6 corresponding to the recess 10 at the base point described above. Center mark 12 on the corresponding lens barrel 7
Display a. Then, a 10 m focus position 12 b and an ∞ focus position 12 c are displayed on the peripheral surface on one side of the lens barrel 7 with the center mark 12 a as a boundary,
2m focus position 12d and 5
A 0 cm focus position 12e and a macro focus position 12f are displayed.

The detection of each focus position described above is performed by using the photo interrupter 13 as an optical element attached to the lens barrel 7 shown in FIG. 2 and the light emitted from the photo interrupter 13 in the quick focus dial 6. This is a method of reading a digital value "1" when reflected by the reflection sheet 14 attached to the peripheral surface, a digital value "0" when not reflected, and a combination of these digital values.

The case of the combination of the 3-bit digital values shown in FIG. 4 will be described below. The photointerrupters 13 are arranged in columns as 13a, 13b, and 13c, of which the photointerrupter 13a is the 0th bit. Similarly, 13b is the first bit and 13c is the second bit. On the other hand, the reflection sheet 14 has a left-right inverted staircase shape. Now, the state of FIG. 4 is a state in which the quick focus dial 6 is not rotated, and at this time, the three photo interrupters 13a, 13b, 13 are
Since the light reflected from the reflection sheet 14 is received by c, it is detected as a digital value "1, 1, 1". Here, for example, the mark 11 of the quick focus dial 6 is set to 1 in order to set the focus position to 10 m.
When rotated to the 0 m focus position 12b, the photo interrupters 13a and 13a,
Since b receives the reflected light and 13c does not receive it, it is detected as a digital value "1, 1, 0".

As described above, each focus position is 3
The digital values from the two photo interrupters 13a, 13b, and 13c are converted into inverting amplifiers 15a, 15b, and 1 respectively.
5c is input to the microcomputer 16 as a combination of digital values as shown in FIG. 5, and from there, the motor 18 is driven via the power driver 17 to operate the inner focus optical system 4 to set a predetermined focus position. Can be made.

The procedure of the quick focus operation will be described below with reference to the flow chart shown in FIG. 6 together with FIG. First, the position of the quick focus dial 6 is detected in step S1. If the digital value is "1, 1, 1" in step S1, the mark 11 on the quick focus dial 6 is the center mark 12a.
Therefore, the normal shooting operation is performed without performing the quick operation. On the other hand, when the digital value is not "1, 1, 1" in step S1, it is determined in step S2 whether the short-distance photographing or the long-distance photographing is performed. Here, if the second bit is the digital value "1", it is detected that the long-distance photographing is performed, and then, in step S3, it is determined whether or not the long-distance photographing is the ∞ focus position. Here, the digital value is "1,
If it is "0, 0", it is determined that the focus position is ∞, and the inner focus optical system 4 is set to the ∞ focus position. Also, the digital value is "1,
If it is "1, 0", it is determined to be the 10 m focus position, and the inner focus optical system 4 is set to the 10 m focus position.

On the other hand, if the second bit is the digital value "0" in step S2, it is detected that the close-up photographing is performed, and further it is determined in step S4 whether the macro focus position is set or not. Here, if the digital value is not "0, 0, 0" in step S4, it is determined that it is not the macro focus position, and it is determined in the next step S5 whether or not it is the 2m focus position. Here, the digital value is "0, 1". If it is “1”, the focus position is set to 2 m. If the digital value is "0, 0, 1" in step S5, 50
cm Focus position is set. If the digital value is "0, 0, 0" in step S4,
The macro focus position is set.

As described above, the present invention relates to the video camera.
The quick focus device, which operates in such a manner as to rotate the quick focus dial 6 to a predetermined focus position, drives the motor 18 in response to a command from the microcomputer 16 to move the inner focus optical system 4 to move the macro from the infinity focus position to the macro position. It is possible to instantly set each focus position having a different focal length between the focus positions. Of course, it is possible to jump the focus position. A graph of this situation is shown in FIG. As can be seen from this graph, each focus position is a measure of the distance to the subject at the time of shooting, and in practice, manual focus ring 5 requires fine focus adjustment after focus setting by quick focus dial 6. Fine adjustment in this case may be performed by slightly rotating the manual focus ring 5.

Further, in FIG. 3, a light emitting section 19 such as an LED is provided corresponding to each focus position 12b to 12f.
When the mark 11 of the quick focus dial 6 is located at the selected focus position, the light emitting section 19 corresponding to this is turned on. With this configuration, it is possible to confirm whether or not the quick focus dial 6 is located at the set focus position by turning on the light emitting unit 19.

Next, another structure of the quick focus device will be described with reference to FIG. The substrate 20 is provided with a switch operating plate 21 as a substantially V-shaped switch button that swings in a seesaw shape with the shaft 20a as a pivot, and one surface of the switch operating plate 21 has a minus-displayed distance. The switch operation piece 21a on the distance photographing side is used, and the surface on the other side is
It is the displayed switch operation piece 21b on the short-distance shooting side. The switch 22b for bit 0 and the switch 22a for bit 1 are arranged on the substrate 20 on the switch operation piece 21a side. A switch 2a for bit 2 and a switch 23b for bit 3 are arranged on the substrate 20 on the side of the switch operation piece 21b.

When the above-mentioned switch piece 21a is pressed weakly, only the switch 22a of bit 1 is turned on,
When the switch piece 21a is strongly pressed, both the bit 1 switch 22a and the bit 0 switch 22b are turned on. Similarly, when the switch piece 21b is pressed lightly, the switch 23a of bit 2 is turned on, and when the switch piece 21b is pressed strongly, both the switch 23a of bit 2 and the switch 23b of bit 3 are turned on.
N operation is performed. The signals from these switches are input to the microcomputer 16 similar to the above. When the switch 22a for bit 1 is turned on, the microcomputer 16 fine-focuses the inner focus optical system toward the long-distance shooting side (fine speed adjustment), and the switch 22b for bit 0 is turned on.
Similarly, the ON operation of is to perform a quick focus (high-speed adjustment) on the long-distance shooting side. Similarly, bit 2 switch 23
The ON operation of “a” is for fine focusing on the close-up shooting side, and the ON operation of the switch 23b of the bit 3 is for quick focusing on the close-up shooting side.

Next, an example of the operation procedure of the quick focus device of FIG. 8 will be described with reference to the flowchart of FIG. It should be noted that each switch has a digital value "0" in the OFF state and a digital value "1" in the ON state. First, in step S1, the operating state of the switch operating plate 21 is determined. When the switch operation plate 21 is not pressed at all, the switches 22a, 22b and 23a, 23b have the digital value "0", and therefore the focus operation is not performed and the normal photographing state is set.

When the bit 2 switch 23a is turned on in step S1, short-distance photographing is determined.
In short-distance photography, in the next step S2, it is determined whether the switch 23b of bit 3 is a digital value "1" or a digital value "0", and when the digital value is "1", the switch 23b is turned off.
Since N operations have been performed, quick focus can be performed on the short-distance shooting side of the optical system. Also,
When the digital value is "0", only the switch 23a is turned on, so that the quick focus optical system becomes fine focus.

On the other hand, when the switch 22a of bit 1 is turned on in step S1, it is determined that long-distance photographing is performed. Then, in the short-distance shooting, in the next step S3, it is determined whether the switch 22b of bit 0 is the digital value "1" or the digital value "0", and when the digital value is "1", the switch 22b is turned on. Quick focusing can be performed on the long-distance shooting side of the focusing optical system. If the digital value is "0", the switch 22a
Since only one of them is turned on, the inner focus optical system becomes fine focus.

Here, in the above-mentioned case, in both cases of short-distance photography and long-distance photography, at the time of actual photography, the quick focus operation is first performed to quickly set the focus position to a predetermined focus position, and then the fine focus is set. Operate to make the final focus.

The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention. For example, although the quick focus device of the 8 mm video camera has been described in this example, it can be widely applied to other video cameras. Further, the invention can be applied to cameras other than video cameras.

[0027]

As described above, the bidet according to the present invention is
The camera has a manual focus ring and quick
With the focus operation section, the quick focus operation section
The inner focus optical system is automatically linked with the dial operation.
Icon-controlled multiple focus positives with different focal lengths
Option can be set instantly selectively,
After that setting, rotate the manual focus ring to
Since the focus can be finely adjusted , when focusing on a subject at the time of shooting, it is possible to instantly set a predetermined focus position, and thus it is possible to quickly respond to a shooting opportunity.

Further, even during the autofocus operation by the inner focus optical system, even if the autofocus operation is lost, it can be corrected by the dial operation of the quick focus device according to the video camera of the present invention, and the operability of the manual focus is greatly improved. Can be improved.

[Brief description of drawings]

FIG. 1 is an external perspective view of a video camera of this example.

FIG. 2 is a cross-sectional view of a mechanism portion of the quick focus device of this example.

FIG. 3 is a front view of a peripheral portion of a quick focus dial.

FIG. 4 is a plan view of a photo interrupter and a reflection sheet.

FIG. 5 is a schematic diagram of an electric system of the quick focus device.

FIG. 6 is a flowchart of the operation of the quick focus device.

FIG. 7 is a step graph of each focus position.

FIG. 8 is a configuration diagram of another example of the quick focus device.

FIG. 9 is a flowchart of the operation of the quick focus device shown in FIG.

[Explanation of symbols]

1 camera body 4 Inner focus optical system 5 Manual focus ring 6 Quick focus dial 7 lens barrel 9 balls 10 click groove 11 mark 12a center mark 12b to 12f Focus position 13, 13a to 13c Photointerrupter 14 Reflective sheet 16 microcomputer 18 motor 19 Light emitting part 20 substrates 21a, 21b Switch operation piece 22a, 22b switch 23a, 23b switch

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-3-215840 (JP, A) JP-A-62-284316 (JP, A) JP-A-61-124927 (JP, A) JP-A-61- 282812 (JP, A) Actual development 4-43834 (JP, U) Actual development 57-7040 (JP, U) Actual development 57-39034 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/225-5/247

Claims (2)

(57) [Claims] 1. A video camera having an inner focus optical system, wherein a fine adjustment focus is provided on a front end side of an outer peripheral surface of a lens barrel of the optical system.
A rotatable manual focus ring
It is equipped with a ring-shape adjacent to the manual focus ring.
Quick includes a focus operation unit, the inner focus optical system microcomputer control in conjunction with the dial operation of the quick focusing operation section, focus
Selective instant for each focus position with different point distance
And the focus position in the quick focus operation section above.
Turn the manual focus ring above after setting
The video camera is characterized in that the focus can be finely adjusted by adjusting the focus . 2. The quick focus operation section is a bow
The above-mentioned focus positions are
The video camera according to claim 1, characterized in that the video camera is positioned on the camera.