JPS646498Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a depth of focus display device in a camera.

A depth of focus display device in a camera consists of aperture scales arranged symmetrically on both sides of a fixed index on the fixed part of the lens barrel, and a distance scale ring that has a distance scale opposite to the fixed index and the aperture scale. It is normal that it is made possible.

This type of distance scale ring is rotatably attached to the fixed part of the lens barrel and simply displays the depth of focus separately from distance adjustment, and it is integrated with a focus adjustment ring that uses a helicoid to adjust the focus. The depth of focus may be displayed at the same time as distance adjustment.

FIG. 1 shows an example of the former, in which a fixed index 2 is arranged on a lens barrel fixing section 1, and aperture scales 3 are arranged symmetrically on both sides of the fixed index 2, and the lens barrel fixing section 1 is rotatably mounted. The distance scale ring 4 is provided with a distance scale 5 in which a metric number sequence 5a based on metric values and a foot number sequence 5b based on foot values are arranged in two rows, facing the fixed index 2 and the aperture scale 3. Sequences 5a and 5b are generally color coded for ease of identification.

FIG. 2 shows an example of the latter, in which a focus adjustment ring 15 is rotatably helicoidally coupled to a lens barrel fixing portion 11 having a fixed index 12 and an aperture scale 13. A distance scale ring 14 having two rows of distance scales 5 consisting of a metric number sequence 5a and a foot number sequence 5b is rotatably mounted.

In either case, the distance scale rings 4 and 14 have the metric number sequence 5a and the foot number sequence 5b written side by side, making the display extremely complicated and often causing a risk of misreading. ,
It was extremely difficult to color each sequence of numbers in a different color when they were close to each other.

Furthermore, in order to solve this problem, it is also possible to arrange the metric number sequence and the foot number sequence at separate positions on the distance scale ring, and to provide a fixed index and an aperture scale at two locations corresponding to each scale value. However, if one of the fixed indicators and the aperture scale is provided in an easy-to-see position, the other becomes difficult to see, and it has been impossible to provide both in easy-to-see positions.

This idea was made in view of the above points,
It is an object of the present invention to provide a depth of focus display device that makes both the meter number series and the foot number series easy to see to avoid misidentification, and has an improved appearance.

Therefore, in the depth of focus display device according to this invention, the meter number row is arranged on one semicircle of the distance scale ring, and the foot number row is arranged on the other half circumference, and an appropriate number is arranged at both ends of the rotation range of each number row. from one number sequence to the other number sequence by providing a restraining means to prevent easy transition from one number sequence to the other number sequence, and by deliberately rotating the distance scale ring against the restraining force. The above object is achieved by making it possible to switch between the fixed index and the distance scale opposite the aperture scale.

Hereinafter, an embodiment of this invention will be described with reference to FIGS. 3 to 7, and the same parts as in FIGS. 1 and 2 will be given the same reference numerals, and the explanation of those parts will be omitted. .

FIG. 3 shows an embodiment of this invention which is an improvement on the conventional example shown in FIG. At the same time, this metric sequence 5
A sequence of feet 5b (not visible in the figure because it is on the back side) is arranged on the other semicircle with a phase shift of 180 degrees from that of a, and the steps shown in Fig. Two circumferential grooves 4a and 4b are provided, and lands 4c and 4d, which are two protruding circumferential surfaces, are formed between each circumferential groove 4a and 4b.

On the other hand, a non-through hole 1a (see FIG. 5) is provided on the outer peripheral surface of the lens barrel fixing portion 1, and the non-through hole 1a
When the compression coil spring 7 and the ball 8 are loosely fitted into the holder and the distance scale ring 4 is attached, the ball 8 is inserted into the circumferential groove 4.
In the state shown in FIG. 5 in which the ball 8 is engaged with the lands 4c and 4b, the rotation is light, and when the ball 8 engages with the lands 4c and 4d, the balls 8 and the lands 4c and 4d constitute a restraining means. The rotation suddenly becomes heavy and prevents the display from moving to the display range of the other number sequence.

However, against this restraining force, the distance scale ring 4
When the ball 8 rotates, the ball 8 returns to the other circumferential groove 4b.
4a, the other number row moves to the display range facing the fixed index 2 and the aperture scale 3, and can be easily rotated within a predetermined range.

Next, FIGS. 6 to 8 show another embodiment of this invention which is an improvement on the conventional example shown in FIG. , two grooves 14a and 14b (for example, V-shaped in cross section) parallel to the optical axis are formed on the inner circumferential surface at both ends of each rotation range of the distance scale ring 14 (Figs. 7 and 8).
(see figure) is provided to fit with the ball 8 similar to the previous embodiment. In addition, 16 is a non-slip processed part.

In this embodiment, while the ball 8 is engaged with the circumferential surface of the distance scale ring 14, the rotation is light, and when the ball 8 is fitted into the groove 14a or 14b, a click action is performed to cause the rotation. The distance scale ring 14 rotates together with the focusing ring 15, but when the distance scale ring 14 is rotated against the restraining force, the ball 8 moves into the groove 14.
a or 14b and can be easily rotated until it fits into the other groove 14b or 14a,
It is possible to switch between the meter number sequence 5a and the foot number sequence 5b.

In the above embodiment, a click-like mechanism such as a ball and a land or a ball and a groove was used as a restraining means to prevent the transition from one number row to the other number row, but a roller or the like may be used instead of the ball. Alternatively, the two may be positively fixed by a groove and a pin that fits into the groove, and rotation in the other direction may be made possible by releasing this fixation.

Furthermore, instead of switching between the metric number sequence and the foot number sequence in this embodiment, it is also possible to switch between the metric number sequence or the foot number sequence and the zone focus mark.

As described above, according to this invention, a metric number sequence is provided on one semicircle of the distance scale ring, and a foot number sequence is provided on the other semicircumference, and either one of the two number sequences can be switched and selected at will. Since the depth of focus display is extremely clear compared to the conventional system in which the meter number row and foot number row are arranged side by side, there is no risk of misidentification, and each value can be easily colored. At the same time, the appearance is greatly improved, which is an excellent effect.

Furthermore, since restraining means are provided at both ends of the rotation range of each number sequence, there is no fear that one number sequence will inadvertently shift from the other number sequence to the display range.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of a conventional camera lens having a depth of focus display device, and FIG. 2 is a plan view showing another example of the conventional camera lens. FIG. 3 is a plan view showing an embodiment in which this invention is applied to the camera lens shown in FIG. 1, FIG. 4 is a perspective view showing only the distance scale ring, and FIG. 5 is a perspective view showing only the distance scale ring. FIG. 3 is a partially enlarged sectional view showing a fitting portion between the lens barrel and the lens barrel. FIG. 6 is a plan view showing an embodiment in which this invention is applied to the camera lens shown in FIG. 2, FIG. 7 is a sectional view taken along the line shown in FIG. 6, and FIG. FIG. 2 is an enlarged cross-sectional view. 1, 11... Lens barrel fixing part, 2, 12... Fixed index, 3, 13... Aperture scale, 4, 14... Distance scale ring, 4c, 4d... Land, 5... Distance scale, 5
a...Meter number sequence, 5b...Feet number sequence, 7...Coil spring, 8...Ball, 15...Focus adjustment ring.

Claims (1)

[Claims for Utility Model Registration] 1. A fixed index provided on a lens barrel fixing part, an aperture scale arranged symmetrically on both sides with this fixed index in between, and the above-mentioned In a depth of focus display device comprising a fixed index and a distance scale ring having a distance scale provided opposite to an aperture scale, a series of meter numbers is displayed on one semicircle of the distance scale ring, and a series of meters is displayed on the other half circumference of the distance scale ring. The number rows of feet are arranged in a row, and restraining means are provided at both ends of the rotation range of each number row to prevent easy transition from one number row to the other number row. A depth of focus display device, characterized in that by rotating a ring, it is possible to switch from one number row to the other number row so that it faces the fixed index and the aperture scale. 2. The depth of focus display device according to claim 1, wherein the distance scale ring is rotatably attached to the lens barrel fixing part. 3. The depth of focus display device according to claim 1, wherein the distance scale ring is rotatably attached to the focus adjustment ring. 4. The restraint means is composed of a ball attached to either the lens barrel fixing part or the distance scale ring and resiliently biased toward the other, and a land provided on the other. A depth of focus display device according to claim 2 of the utility model registration claim. 5. A utility model in which the restraint means is constituted by a ball attached to either a focus adjustment ring or a distance scale ring and resiliently biased toward the other, and a groove provided in the other. A depth of focus display device according to registered claim 3.