CN1031136A

CN1031136A - Automatic focus

Info

Publication number: CN1031136A
Application number: CN 87101156
Authority: CN
Inventors: 拉姆·温格·舍格·萨姆
Original assignee: Archio Industrial Co ltd
Current assignee: Archio Industrial Co ltd
Priority date: 1987-08-07
Filing date: 1987-12-18
Publication date: 1989-02-15
Also published as: GB8718722D0; GB2207828A

Abstract

A kind of automatic focusing system that depends on the photograph usefulness of the contrast light that detects on the object to be focused on and dark space.This is gratifying under good illumination condition, but if then inoperative when needing flash illumination.The light that has a kind of condition of installing realization focusing to be to use a kind of powerful light emitting diode (LED) to send is by a grid lighting object.Light emitting diode costs an arm and a leg and needs big energy.The present invention is with a kind of simple filament bulb, and bright filament is focused on the object so that an area of illumination to be provided, and therefore can overcome above-mentioned shortcoming.

Description

Automatic focus

The present invention system is relevant with the automatic focus in the photography.

Camera with automatic focus structure is known by people, and has used various devices.As an example, have and a kind ofly install utilization and come judging distance, and a kind of technology then is to detect the light contrast of object and background from the ultrasound wave of object reflection.

Therefore a kind of method in back needs great light.This is satisfiable when taking pictures under daylight, still, when using the flash of light lamp body for illumination, also has many problems here.Therefore, after the trigger flashing lamp, just have contrast, and the bright time of flashlamp fall short of and make camera not detect and to make lens focus light, so, must before flashlamp triggers, finish focusing.

Can realize above-mentioned purpose according to a kind of known technology, a kind of flash unit promptly is provided, perhaps make camera have discrete lighting device, it can throw a kind of high contrast picture to object to be focused on before flashlamp triggers.For example, obtain this high contrast picture, can use a kind of powerful light emitting diode, its light is incident upon the picture of grid on the object to be focused on then by a grid.This will provide a kind of high contrast optical pattern on object, and will make the focusing structure of camera and/or flasher in the flash device preceding work that is triggered.

The shortcoming of this device is that the cost of light emitting diode is very high, because it needs very big power, and will use the energy of a great deal of to provide effective lighting to object, makes the automatic focus structure measure the contrast light and the dark space of projection grid.

Therefore, purpose of the present invention just provides a kind of fairly simple device that need not use such expensive device.

In automatic focusing system according to a kind of usefulness of taking a picture provided by the present invention, contrast light and dark space that utilization projects on the object to be focused on are detected focusing, the bright filament of a bulb is projected on the object can obtain above-mentioned light and dark space.

According to the present invention, in this way, people can use a kind of very cheap and a kind of device that the bulb form of conduction filament is arranged of being easy to obtain, and the resembling of filament of will in fact turning white-hot projects on the object to be focused on.This bulb can have been bought everywhere as a kind of small-sized quite cheap coml device, and only has quite an amount of energy to be used for illumination.Therefore, people can avoid using very expensive light emitting diode.

By example the present invention is illustrated with reference to the accompanying drawings.In the accompanying drawings:

Fig. 1 represents the principle synoptic diagram that is applicable to self-focusing camera of the present invention, and the flasher of this camera has structure of the present invention;

Fig. 2 is the enlarged drawing of synoptic diagram details among Fig. 1;

Fig. 3 is the decomposition enlarging projection figure according to a kind of structure type of the present invention;

Fig. 4 is the perspective view according to a kind of structure type of having revised of the present invention of a kind of Fig. 3 of being similar to.

Represented as Fig. 1 and Fig. 2, lighting device 10 according to the present invention is installed in the chamber 11 of a discrete electronic flash equipment 12, and flasher 12 is received on the camera 13 by hot shoe 14 in the ordinary way.If have complete flasher on the camera, then install 10 and also can be positioned at camera 12 casings.

Camera lens 15 is accepted from the picture in zone 16.

Device 10 is made up of a small electric bulb 22 with filament 24.The light of bulb is focused on by convex lens 26, and projects on the zone 16.In Fig. 1, being seen owing to obtain a bright image 28 of filament 24, this as 28 and the dark background of its both sides form strong contrast.

Bulb 22 is installed on the garden cylindricality cap 32, and cap 32 is fixed in the garden cylindrical sleeve 34 and slidably, and sleeve 34 has constituted a part of supporting the cover 36 of convex lens 26.As following to introduce.When device 10 began to assemble, cylindricality cap 32 moved with respect to sleeve 34 and makes light bulb filament be positioned at the focus place of lens 26.In this way, at this moment the picture of lens will quite clearly be throwed and will be limited on the object in camera 12 the place aheads.

Therefore, the automatic focusing system (not shown) of camera can be utilized by the zone of the bright image 28 of projection filament and the dark on every side farsighted  of  Na Kangmu bed and turn on the object that hinders in the well-behaved scold  6 of ouch  woman rice strive forward.Although when taking pictures with flasher, different with photography in natural light, there are not enough light or light contrast to make automatic focusing system work here, above-mentioned purpose also can realize.

Because automatic focusing system is a kind of commonplace components by known method work, thereby it is not expressed or it is described in detail.

If necessary, can provide more than one picture 28a in zone 16, and represent to exist second picture 28 among Fig. 1.Can install 10 next doors by being positioned at first, second same device 10 provides picture 28a, and the embodiment among following Fig. 3 that will introduce has so dual arrangement.

As shown in Figure 1, as between 28 scope dictates online 37 and 38 that occur.Similarly, the zone 16 of being found a view by lens 15 is limited between straight line 39 and 40.As 28 and regional 16 zones that overlap fully are regional A, but are distal to A from the distance of camera.For the picture 28 of regional A front portion, it may not can appear in the zone 16, perhaps may occur but is not so that the automatic focus arrangement works of camera.

Therefore, provide an illuminating lens 42 in the front portion of lens 26.This illuminating lens comprises a component prism 42a, and it projects in straight line 46 and the 48 determined zones an additional bright image 44 of filament 24.As 44 outsides that are arranged in the zone 16 of regional A, therefore irrelevant with focusing.Yet in area B, as 44 fill-ins that become as 28, thereby provide a contrast, automatic focusing device can be to focus than the picture of the more close camera 13 of regional A with it.

It is very important that the bright image 28 that filament 24 is throwed is positioned at camera lens footprint 16.During beginning assembling device 10, can accomplish this point.

Fig. 3 has represented to install a kind of version of 10 in more detail according to the present invention.Just as explained above, bulb 22 is installed in the garden cylindricality cap 32, and sleeve 34 can slide relatively, so that filament is positioned on the focus of lens 26.With bulb energising, in sleeve 34 mobile cap 32 up to projection as this point of just being not difficult to accomplish till clear, in this position that cap 32 is bonding or be welded on the sleeve 34 then, it is permanently secured on this position.

In addition, sleeve 34 is received on the metal frame that can vertically regulate 52.Then move, refill on the support 36 with afterframe 54 by a horizontal adjustment framework 54.

Framework 52 by framework 54 slidably property move, and can move at both direction up and down with respect to the latter.Moving up and down of it by screw 56 controls that are screwed on the framework 52, and abut against on the framework 54.Therefore, the rotation of screw 56 will make filament 24 move up and down, so just can make picture 28 realize vertical adjustment with respect to zone 16.

And framework 54 has the ridge 58 that extends laterally, and it can slide on the left and right directions of support 36.By this move left and right of screw 60 controls that is screwed on the framework 54, and abut against on the support 36.Therefore, the rotation of screw 60 makes the filament move left and right thereby vertical regulatory function is provided.

In this way, just can make between erecting stage in beginning the filament that throwed as 28 with respect to zone about 16 with move up and down, and the rotation by screw 56 and 60 makes the reaching in regional 16 on the desired position as 28 of filament of projection.

In fact expressed two devices 10 among Fig. 3, each all has lens 26 that are positioned at chamber 36.The advantage of doing like this is can provide two clearly as 28, and this helps the reliability of automatic focusing.In addition, the levelness by making filament or highly be offset, people just can adjust hot shoe on the flasher 12 and the undesirable gap between the socket on the camera 13.Require second bulb of installing in addition, so that a lamp when being spoilt, installing 10 endures and uses a long time.

Fig. 4 has represented a kind of improved form of device 10a.This device in, with bulb 22 be installed in lens 26 below, catoptron 70 throws the light scioptics of filament 24 forward.

10 compare with device, in the concrete structure of device 10a, the mounting means of lens make its can not be up and down and move left and right regulate and make as 28 and drop in regional 16.The substitute is, in device 10a, bulb is fixed in the 36a of chamber, chamber 36a can regulate in the inside of the chamber 11 of flasher 12.

Like this, chamber 36 can be the axle motion around axis 71 by first framework 72, therefore feasible can moving at above-below direction as 28 of being throwed.This moving by 74 controls of the screw on the teat 76 that is screwed in chamber 36a, and the end of screw 74 leans against not expression among the 11(Fig. 4 of chamber) on.Regulate bolt 74 chamber 36a will be rotated relative to axle 71, at this moment it will overcome the acting force that is positioned at the spring 80 on the axle 71.

In addition, first framework 72 is supported by second framework 82.It has knockdown vertical ridge 83, can be used for being connected with chamber 11, and first framework can rotate along its vertical axis 84 with respect to bolt 84.Bolt 88 by being screwed into chamber 11 axle 86 is relatively regulated, and this moment, it leaned against on the outshot 90 of first direction support 72.This bolt 88 overcomes the acting force that is positioned near the spring 92 the bolt 84 and works, and this spring works between ridge 83 and the vertical ridge 96 at first framework 72.

Therefore, when device 10a starting apparatus, can will be limited in the zone 16 as 28 by adjusting screw 74 and 88.

Illustrated device 10 is contained in discrete electronic flash equipment 12 inside, and flasher is very common and need not do further explanation, and it can be started working before flash of light triggers.Like this when normal the use, when using strobo photography, the user of camera 13 just can observe scenery by view finder, can connect bulb 24 when beginning to press the shutter hook and the shape bright image 28 of trampling of the filament of projection is offered the automatic focusing structure, make it camera lens 15 is directly focused on the scenery.The action of consequential then shutter hook will make the shutter of camera 13 open and with a kind of very common mode trigger flashing device 12.

A kind of automatic focusing system of following the automatic focusing system of camera to use, here to its introduction be with reference to the Fig. 1 in the accompanying drawing to Fig. 3 or Fig. 1, Fig. 2 and Fig. 4 carry out.

Claims

1, a kind of automatic focusing system that is used to take a picture, use the contrast light and the dark space of throwing on object to be focused on to detect the focusing situation, it is characterized in that: be to provide a bright area or contrast light zone and dark space on the object by the bright filament of bulb is incident upon.

2, the described a kind of automatic focusing system of claim 1, wherein bulb is installed in the electronic flash equipment, and this electronic flash equipment can be received on the camera by means of hot shoe.

3, a kind of automatic focusing system described in claim 1 or 2, wherein bulb is installed in the cap of a garden cylindricality, this cap is fixed in the column type sleeve and slidably, make cap and sleeve can between centers, relatively move each other, move axially by this, can make described light bulb filament assemble interval and be focused at this device.

4, a kind of automatic focusing system described in the arbitrary claim in front, it includes a pair of bulb placed side by side, arranges their bright filament to make it to be incident upon on the object, and two clear zones are provided at least.

5, a kind of automatic focusing system described in arbitrary as the aforementioned claim, also comprise a light-dividing device, it can make the filament of each bulb produce two pictures at least, and these two pictures are separated from each other, the object zone of the topped increase of available contrast light and dark space.

6, a kind of automatic focusing system described in claim 5, light-dividing device wherein is made up of a prism.

7, a kind of automatic focusing system described in arbitrary as the aforementioned claim, in order to begin assembling, this device also includes the mechanism that each bulb is moved with respect to projection lens, bulb can with respect to the axis of lens meet at right angles and laterally both direction move, make the projection of filament look like to be adjusted at the zone at object place to be focused on.

8, a kind of automatic focusing system described in claim 7, further include first bulb supporting frame and one second framework, first framework can relative second framework moves along an axle, second framework then relatively this device unit room along moving with a described rectangular axle.

9, a kind of autofocus system described in the claim 7 also comprises a frame mounting, is used to provide picture that described motion makes projection and waits to focus on the regional consistent of object.

10, a kind of automatic focusing system described in each above-mentioned claim also includes a mirror, and it can reflex to the light of bulb on another axis that is complementary with the bulb projecting mirror from an axis.