Electronic motion picture camera

0001The invention relates to an electronic motion picture camera with an optical receiving system and a beam splitter in the receiver beam path a leading to an optoelectronic image sensor recording beam path and a leading to an optical viewfinder viewfinder beam path divides.

0002In electronic motion picture cameras recorded the useful signal usually as a monitor image in an electronic viewfinder or on one mounted on the camera screen. The thus reproduced recorded image is, for example, the control of Focus. An electronic viewfinder has the disadvantage that the environment of the Recording image can not be observed. Thus, potentially disturbing objects not out of the captured image section are detected before they enter the recorded image. are especially Viewfinder based on electronic displays, in reproduction quality limited.

0003There are also electronic motion picture cameras known that a optical viewfinder are provided. In these cameras, a part of of the optical receiving system detected light stream into a sensor for recording connected in parallel optical system directed that for the cameraman the same image recording indicates that recorded from the Recording Sensor becomes. This allows a high image quality of the viewfinder achieved will. A disadvantage, however, that the cameraman no additional Image information can be made available.

0004It is therefore an object of the invention, an electronic motion picture camera create, the viewfinder has a high image quality and for different Anförderungen regarding the reproduction of the recording picture is and additional image information flexibly.

0005This object is achieved by a motion picture camera with the features of Claim 1., and in particular in that the camera is a comprising electronic display for displaying an auxiliary image, and that an optical image mixer is arranged in the viewfinder beam path, through an imaged by the receiving optics Up and reproduced by the electronic display additional image such in are steered towards the viewfinder that the recorded image, or the Additional image, or the recorded image and the auxiliary image as a unified Image are observable in the viewfinder.

0006The receiving optical system forms the image being shot is along the recording beam path on the Imager and brings the Up Moreover, in the viewfinder display, the camera according to the invention a hybrid viewfinder system with two superimposed beam paths has: In the viewfinder beam path of an optical viewfinder is an optical vision mixer integrated, the detected the appearance of the receiver optics Recording image and a generated by an electronic display Additional image allows, the captured image and the auxiliary image the Viewers in the viewfinder as a single, unified motion picture or still picture can be represented. As a result, the high image quality of a optical viewfinder combined with the possibility, by means of an electronic Display an additional image information in the viewfinder beam path einzuspiegeln or optically initiated otherwise.

0007Instead of a common representation of the female image and the Additional image as a single image can optionally only from the receiving optics pictured receiving image in the viewfinder to display be accommodated, for example, before the actual recording means the recording sensor. Optionally, only the from the illustrated electronic display reproduced supplementary image in the viewfinder will. This possibility is particularly advantageous if, due to poor illumination of the recording subject the received light completely on the Imager and not towards the viewfinder is to be routed. In this case, the viewfinder by means of the electronic Display and the image mixer used as an electronic viewfinder will.

0008The additional picture cameraman while recording hence in support a variety of ways, the image information contained therein selected flexibly depending on the specific recording situation can be. The actual recording image and the auxiliary image can while optionally simultaneously, alternatively each other, alternating in time or alternately with a temporal overlap in the optical viewfinder being represented.

0009In particular, the electronic display is for reproducing motion pictures formed or still images that the product placed in the viewfinder display complement actual recording image. Such motion pictures can on the display be reproduced, just essentially simultaneously, ie synchronously or with a due time the sensor electronics Delay, be recorded by the recording sensor. Thereby be able to that shown in the viewfinder on the receiving optics Up and reproduced from the display recording picture Receiving sensor complement in time so that the observable in the viewfinder Up does not flicker.

0010Since the viewfinder is formed as an optical viewfinder, a high ensures image quality without the known technical limitations an electronic monitor image. Moreover, the optical viewfinder be such configured that the optical receiving system towards Viewfinder pictured and there observable image section is greater than the actually absorbed by the Imager picture Section recording picture, so that the cameraman and the environment of the actual can watch recorded framing.

0011Although an optical viewfinder is provided, this can by means of electronic display and the optical vision mixer used to are already recorded and stored motion picture sequences sift. Thus, the optical viewfinder can be used to control an already earlier recorded motion picture sequence used will. Saved motion picture sequences can even during a new recording are superimposed on the actual image recording, For example, as a reference for the camera operator.

0012Alternatively, the actual recorded image playback different Brightness range markings of field markings or distance range markings (in the form of a "Depth map") are superimposed, that of the cameraman while Recording provide additional assistance. It is also possible, by means of the electronic display and the optical vision mixer image format markings or alphanumeric information in the viewfinder bring representation.

0013A particular advantage is obtained by using a rotating mirror shutter as a beam splitter in the receiver beam path: In this case, leads the rotation of the mirror shutter inevitably to an intermittent Hiding the light incident on the image sensor. In the Inventive camera can fade-out time intervals over those time intervals in which the incident light in the direction of is deflected viewfinder can be reduced. The thus caused Flickering in the viewfinder can namely be compensated for that on the electronic display and the optical vision mixer from the initiated Sensor recorded picture image in the viewfinder beam path becomes.

0014Preferably, the camera is explained as a digital electronic motion picture camera with the Imager downstream digitizer educated.

0015The invention also relates to the use of an optical an imaged image mixer for the preparation of a receiving optics Recording image and a reproduced from an electronic display Additional image in an optical viewfinder of an electronic motion picture camera.

0016Furthermore, the invention relates to a process for preparing a recording image and an additional image in an optical viewfinder an electronic motion picture camera, and a receiving optical system, the Up along a recording beam path to an Imager mapping and viewfinder along a beam path in a viewfinder brings to representation, an electronic display the auxiliary image reproduces, and wherein an optical image of the mixer of the receiver optics pictured receiving image and the electronic of the Ad directs reproduced supplementary image so towards the viewfinder, that the recorded image, or the additional image, or the image being shot and the auxiliary image are observable as a unified image in the viewfinder.

0017Further embodiments of the invention are defined in the subclaims called. The invention will now be of example only with Referring to the drawings, wherein like elements are indicated by the same reference numerals.<dl tsize="12" compact="compact"><dt>FIGS. 1-8</dt><dd>show various embodiments of an electronic Motion picture camera.</dd></dl>

0018FIG. 1 shows a first embodiment of an electronic motion picture camera. This has a receiving optical system 11, which recorded the Motion picture mapping along a receive beam path. 13 By means of a as a beam splitter serving mirror shutter 15, by a drive unit 17 can be driven to a rotational motion, the along the reception beam path 13 incident light alternately transmitted towards a receiving beam path 19 or toward a viewfinder beam path 21 is deflected. has for this purpose the mirror shutter 15 a passband 23 and a mirrored Blanking 25th

0019An image captured by the receiving optical system 11 receiving image is thus alternately along the receiving beam path 19 to an optoelectronic Imager 27 ready and along the finder optical path 21 deflected in order in an optical viewfinder 29 for displaying to be brought. The receiving sensor 27 is, for example, by a CCD or CMOS imager formed, and it has a signal output 31 for outputting a reception signal.

0020In the viewfinder beam path 21 a focusing screen 33 is arranged, to which the is imaged by the receiving optics 11 captured Up, unless the blanking 25 of the mirror shutter 15 in the received beam path 13 is. The result of the focusing screen 33 a real image, the cameraman can look through the viewfinder 29th

0021In the viewfinder beam path 21, an optical image mixer is further arranged 35, the one hand, the observation of the focusing screen 33 by the Viewfinder 29 allows on the other hand a display of an electronic brings to represent 37 reproduced supplementary image in the viewfinder 29th By means of the optical image mixer 35 is the focusing screen image so the Additional picture of the electronic display superimposed 37, wherein a viewer with a corresponding adjustment of the two optical branches the two superimposed images on the viewfinder 29 appear as a single image. For this purpose, the display 37 and the ground glass 33 are in the same Object plane or focal position of the viewfinder 29 is arranged.

0022The optical image mixer 35 is, for example, by a partially transparent Mirror formed. The electronic display 37 is, for example, by a liquid crystal monitor, an LCD monitor (thin film transistor) or a CRT monitor (CRT, cathode ray tube) formed. It has a Signal input 39, via which the additional image and corresponding image signals can be supplied.

0023The use of an optical viewfinder 29 in conjunction with a Matt disk 33 ensures a high quality of the viewfinder image. Despite the use of a finder optical system can cameraman in Viewfinder 29 by the display 37 and the image mixer 35 an additional image are displayed, thereby recording in diverse and flexibly support.

0024In particular, it is possible that on the electronic display 37 moving images, or still images are reproduced, the the at the screen complete 33 Up intermittently imaged in time so that a 15 possibly evoked by the rotation of the mirror shutter Flickering of the recording image formed is avoided. The electronic Display 37 and the optical vision mixer 35 can also are used, it has been recorded moving picture sequence in the viewfinder 29 display for control purposes. Alternatively or additionally, by the display 37 and the image mixer 35 any other image information be reflected into the viewfinder beam path 21st

0025Another advantage of this camera is that the preparations a recording while the mirror shutter 15 is still standing and the Passband 23 is in the received beam path 13, an image seen in the viewfinder 29 is: The Imager 27 may during the Shooting preparation a reception signal supply, the example is used to test and reference purposes. At the same time, despite standing Mirror shutter 15, an image observation in the viewfinder 29 possible by the received signal of the receiving sensor 27 via the signal input 39 of the electronic display 37 is supplied to and from this the optical image mixer 35 is brought in the viewfinder 29 to display.

0026Preferably, the camera is equipped with an adjusting device, by which the Play the additional image of the electronic display 37 relative to the can be adjusted at the screen 33 shown Up. By such adjustment, for example, the size, Position, orientation, or other geometric properties of be additional image adapted to the viewfinder 29, a geometry identical to achieve superposition with the image recording. Preferably carried out this Adjustment electronically.

0027Of course, it is other than as shown in FIG. 1 also possible that the focusing screen 33, the optical image mixer 35 and the viewfinder 29 is L-shaped are arranged so that the image mixer 35 the imaged on the focusing screen 33 Up towards the sensor 29 deflects, while the additional screen of the electronic display 37, for example, straight through the image mixer 35 towards the viewfinder 29 is reproduced.

0028The use of ground glass 33 is not mandatory. Instead the receiving optics 11 may in the viewfinder beam path 21 a virtual create image of the viewfinder 29, together with the additional screen Display 37 can be viewed.

0029Instead of the mirror shutter 15 can in principle also a beamsplitter be provided which splits the incident luminous flux continuously.

0030FIG. 2 shows a development of the embodiment of FIG. 1. In this is the receiving sensor 27 downstream signal processing device 41 provided. This prepares the received signal of Receiving sensor 27, for example, by amplification and preferably by additional digitization. The conditioned signal is to an output signal at the output 31 as a useful signal and the other transmitted to the electronic display 37th

0031The electronic display 37 can thus the current signal received by the Receiving sensor 27 play in real time as an additional image. Thereby in the optical image mixer 35 the recorded by the image sensor 27 Up to that recording image superimposed or temporally supplemented that of the receiving optical system 11 via the rotating mirror shutter 15 is displayed on the TV screen 33rd Thus, appears in the viewfinder 29 observable Up especially quiet, without annoying flickering.

0032Optionally, a controller 43 is provided, which drive unit the 17 of the mirror shutter 15, the receiving sensor 27 and the electronic Display 37 synchronized such that the viewfinder 29 substantially alternately, that is exactly alternately or with a temporal overlap, that of the receiving optical system 11 via the mirror shutter 15 at the screen 33 pictured receiving image and the electronic of the Display 37 reproduced signal received by the receiving sensor 27 can be observed.

0033The control device 43 shown in FIG. 2, the drive unit 17 the mirror shutter 15 also ansteueren such that recorded during a Image sequence, the receiving optical system 11, the image recording only reflects on the Imager 27th In other words, the mirror shutter 15 temporarily halted so that the Passband 23 is in the received beam path. 13 Since the Up is therefore no longer displayed on the TV screen 33, causes the controller 43 that the display 37 during the entire image sequence the current signal received by the receiving sensor 27 represents as an additional image. The viewfinder 29 thus serves as a purely electronic Viewfinder. This is in low light conditions of particular Advantageous, since the entire light receiving completely onto the receiving sensor can be steered 27th

0034Fig. 3 shows a further development in which the image sensor 27 and a Signal processing device 41 downstream image storage means 45 is. This provides at an output 31 of the conditioned signal is the received signal of the receiving sensor 27. Another signal output connected to an input of the electronic display 37th Thus, Moving picture data or still picture data at an earlier time recorded by the image sensor 27 and the image storage device 45 have been stored, displayed on the electronic display 37 and thus be observed in the optical viewfinder 29th The Image storage means 45 thereby enables the viewing of a previously recorded motion picture sequence in the viewfinder 29, without the need for an additional screen monitor is required.

0035A particular advantage of the embodiment of FIG. 3 is that the imaged at the screen 33 during a new recording Up a previously recorded by the receiving sensor 27 Motion picture sequence may be superimposed, for example, the cameraman a reference for the camera operator to offer.

0036Alternatively or additionally, the electronic display 37 or a connected therewith data buffer having a signal input 39, to to an external storage device 47 may be connected to the electronic display supply 37 moving picture data or still image data, the means of the optical image mixer 35 in the viewfinder 29 as an additional image to be reproduced. By connecting an external Memory means 47 it is possible in particular to the electronic Display 37 mathematically generated or edited image elements reproduce, which are inserted into the post-recording should. By this image elements already during the recording of the Cinematographer be visualized, this may the interaction consider the real scene with the virtual pixels. The camera work is thereby greatly facilitated, and it is avoided that a recorded motion picture sequence, subsequently as unsuitable turns for the desired post.

0037Especially advantageous is the described fading in an additional Motion picture sequence in the optical viewfinder 29 so-called so for the Compositing, ie for recording the subject against a blue Background (blue screen) for the subsequent overlaying of several various designs in the post. For example, if the Recording a real actor in front of a blue screen later a view of another artificial or trick technically produced Figure (eg, an alien, or the like) to be overlaid, so can already during the recording of the real actor before Bluescreen cameraman presentation artificially generated by the electronic display 37 displayed in the optical viewfinder 29 will. The cameraman can thus the real intake and the addition faded representation of trick technical subject simultaneously monitor and influence the camera accordingly so that it is ensured that the final superposing the real and artificial scene in the post will be trouble.

0038Fig. 4 shows a modification of the embodiment of FIG. 3. In this is an evaluation and control device 49 on the input side with a the receiving sensor 27 downstream signal processing device 41.. On the output side, the evaluation and control device 49 connected to an image storage device 45, with the is electronic display 37 connected.

0039The evaluation and control device 49 is such configured that the time of reproduction of an image memory in the device 45 stored motion picture sequence on the electronic display 37 depending controlled by the camera running. In a simple case, the Motion picture sequence reproduced once the evaluation and control device 49 the beginning of the camera is running or a recording by the Receiving sensor 27 detects. The evaluation and control device 49 may also be configured such that it the current reception signal the receiving sensor 27 with respect to a moving object within recording picture evaluates and in response thereto, the playback frequency controls, with the value stored in the image storing means 45 Moving picture data or still image data to the electronic display 37 are reproduced.

0040In the image storage device 45 may, as in connection with FIG. 3 explained, for example, saved a previously recorded motion picture sequence be serving as a reference for the camera, or in the image storing means corresponding 45 stored image data virtual picture elements included in the post-recording to be. The evaluation and control device 49 is capable of, the Play this stored image data (start and end points, running speed) depending on the camera running and / or from the received signal the recording sensor to control 27 to a synchronization the stored events with the real recording needs.

0041Also in the embodiment of FIG. 4 can of electronic Display 37 einzuspielenden image data alternatively from an external Storage means come. In this case, the auxiliary image is a signal input 39 of the camera is supplied, wherein the image memory means 45 can serve as a data buffer.

0042Fig. 5 shows an embodiment in which the display 37 on the input side is connected to an image generator 51 as an additional image of the the display should be 37 reproduced, for example, screen area indicia Image format markings, other graphic information generated or alphanumeric information.

0043For example, by the image generator 51, the display 37 and the Image mixer 35 the captured image shown on the TV screen 33 a frame are superimposed, depending to the determination of the uptake (Cinema or television) compose the image of the associated image format marked. Thus, a permanent mark of the focusing screen 33 or Replacing a differently labeled faceplates 33 unnecessary. In the image information generated by the image generator 51 may for example, also an alphanumeric identification of set aperture or the set-focus elements act.

0044Optionally, the image generator 51 is the input side to an evaluation and Control means 49 connected, on the input side in turn with the Imager 27 or an associated signal processing device connected is. The evaluation and control device 49 evaluates the Receiving signal of the receiving sensor 27 in terms of predetermined Brightness or sharpness values ​​and causes the image generator Generating corresponding brightness range markings or Focus range markings that on the electronic display 37 are reproduced. Thus, the observed at the focusing screen 33 Up from the sensor image specially prepared electronic Image superimposed to the cameraman an on areas with certain brightness or sharpness to point (modulation frequency). These areas may be the image generator 51, for example by hatching are identified.

0045According to an advantageous embodiment, the evaluation and Control device 49, the received signal of the receiving sensor 27 for the individual pixels of the image recording, for example by means of a Comparator each having an upper brightness threshold or a lower brightness threshold or with the two mentioned Compare brightness thresholds. In this case, the evaluation and Control device 49 at least a brightness range of the recording picture calculate or determine within which of the pixels recording picture, or at least for a majority of Pixels each receive signal the upper brightness threshold exceeds or falls below the lower brightness threshold. The image generator 51 generated from the thus specified Brightness ranges corresponding brightness range markings, For example, the above mentioned hatchings. This brightness range markings are therefore produced on the display 37 and are Thus in the optical viewfinder 29 as warnings superimposed on the captured image visible.

0046The generation and display of such brightness range markings just in motion picture cameras with an optoelectronic image sensor important because these generally lower brightness dynamics has than conventional photochemical footage, the thresholds for critical upper and lower brightness values are sensor-dependent. It is therefore advantageous if the cameraman Image areas can be displayed, in which the recorded Brightness values ​​of the subject could prove problematic, so the cameraman while the camera operator who explained can be considered warnings or image field markings. This function is the one for a test run important optionally To change the set (for example, by a sunlight is moved reflective coffee pot in the shade). On the other hand This function is for the actual, final recording important because the cameraman thus has a control option that actually recorded no problematic brightness even during recording will. If on the other hand only after the recording - in fact the sighting of the recorded scene - would point out that problematic brightness values ​​or ranges have been recorded, would be a subsequent again to record the scene usually very complicated or even impossible because the set adjusted again would be.

0047It is important that the cameraman himself - and not any other Person - observe the described brightness range markings may, in the optical viewfinder. The cameraman can thus even the control of the recording picture Helligkeitsaussteuerung retain and possibly affect correspondingly the camera operator, and he does not need therefor to the use of the conventional optical Viewfinder 29 without. It is also important that the cameraman not only a simple warning signal is transmitted, but concretely is displayed, in which the screen of the error occurs.

0048Of importance is the function of displaying the image area markings and in particular of brightness range markings also for the already mentioned in connection with Fig. 3 mentioned compositing So for recording the subject against a blue screen. is Here it namely important that the division of the recording image in different Color or brightness areas - so the quality of segmenting - can be observed and controlled. For example, it may prove to be prove problematic when a person with a green or even blue garment is filmed in front of the blue screen. By explained comparing the received signals with respective thresholds can cinematographer potentially critical image areas are displayed.

0049For said application of the compositing it is advantageous when the receiving signals from the receiving sensor 27 for the various Pixels respectively in terms of the colors red, green and blue with different comparing thresholds, as for example the Receiving signals of the color blue are more critical than the received signals the color green. There must be a comparison, not necessarily for each color be carried out with a brightness threshold. For example is such a comparison for the color red in terms of Compositing not mandatory.

0050Fig. 6 shows a modification of the embodiment shown in FIG. 5, at the in addition a distance measurement device 53 is provided. This is for example, by an infrared probe or a laser rangefinder educated. The distance measuring device 53 is provided with an evaluation and control means 49 connected, on the input side to the receiving sensor 27 and the output side to an image generator 51 for the electronic display 37 is connected.

0051The distance measuring device 53 is capable of removing the camera to a subject within the recorded object space measure. The corresponding measurement signal can and by the evaluation Control device 49 to different distance ranges of the object space and thus the recorded by the image sensor 27 receiving image be evaluated. Depending on this evaluation, causes the evaluation and control device 49 to the image generator 51 to generate corresponding distance range markings that reproduced by the electronic display 37 and thus the matte field are superimposed.

0052In this way, the cameraman in the viewfinder 29 is a "depth map" provided that - for example, different Color (false color), by hatching or by representation of different distance ranges with different Brightness - rapid identification of the object distances and / or the Focal plane allows. This is in particular the setting a desired depth of field easier. Of course 53 may be provided a plurality of distance measuring devices to the different distance ranges of the recording picture quickly and to capture high resolution.

0053Fig. 7 shows an embodiment with a photodetector 55, which Brightness of the imaged by the receiving optics 11 at the screen 33 Recording image measures. The photodetector 55 is a brightness control device 57 is connected, as a function of the measured Brightness of the focusing screen image brightness playing the Additional image controls on the electronic display 37th The brightness control device 57 may for example be configured such that the imaged by the receiving optics 11 Up and hereby superimposed auxiliary image of the electronic display 37 from the viewer the same brightness or with a constant brightness difference perceived to be.

0054Instead of the illustrated brightness control device 57 with photodetector 55 a simple brightness control device may be provided be connected with the electronic display 37 to the brightness Adjust the playback of the additional image to a desired value to.

0055For the embodiment shown in FIG. 1, it is preferable if the optical Video mixer 35 - for example in the form of a partially transparent mirror - both the imaged by the receiving optics 11 at the screen 33 Recording image and the additional image of the electronic display 37 able to direct the same towards the viewfinder 29th

0056Fig. 8 shows an alternative to this embodiment in which the optical Video mixer 35 either the imaged by the receiving optics 11 Up, or the auxiliary image of the electrical display 37, or simultaneously the Up and the auxiliary image towards the viewfinder 29 steers. For this purpose, the video mixer 35 a fully drained Section 59, a fully reflecting section 61 and a partially reflecting / partially transmitting portion 63 have that be introduced either in the viewfinder beam path 21st For example can the three sections 59, 61, 63 to an image mixer carousel be arranged by its rotation to the desired section in the Viewfinder beam path is placed 21st

0057As an alternative to such a carousel, the video mixer 35 also allow a continuous variation of the division ratio, so that for the viewer, the relative proportions of the two originals, ie of at the focusing screen 33 reproduced recording image and of the Display 37 reproduced additional image shifted from each other can be. For example, the video mixer 35 a liquid crystal mirror having controllable permeability, so that depending on Arrangement of the liquid crystals, a greater proportion of the recording picture or a larger proportion of the additional image towards the viewfinder 29 is directed.

0058Finally, it is to be noted that in connection with FIGS. 1 combined with each other to 8 described embodiments can be made to the image mixer 35 and the display 37 even more versatile use.

LIST OF REFERENCE NUMBERS

0059<dl tsize="2" compact="compact"><dt>11</dt><dd>receiving optics</dd><dt>13</dt><dd>Received beam path</dd><dt>15</dt><dd>mirror shutter</dd><dt>17</dt><dd>drive unit</dd><dt>19</dt><dd>Recording beam path</dd><dt>21</dt><dd>Finder beam path</dd><dt>23</dt><dd>Passband</dd><dt>25</dt><dd>blanking</dd><dt>27</dt><dd>Imager</dd><dt>29</dt><dd>viewfinder</dd><dt>31</dt><dd>signal output</dd><dt>33</dt><dd>focusing screen</dd><dt>35</dt><dd>optical vision mixer</dd><dt>37</dt><dd>electronic display</dd><dt>39</dt><dd>signal input</dd><dt>41</dt><dd>Signal processing means</dd><dt>43</dt><dd>controller</dd><dt>45</dt><dd>Image storage means</dd><dt>47</dt><dd>external storage device</dd><dt>49</dt><dd>Evaluation and control device</dd><dt>51</dt><dd>image generator</dd><dt>53</dt><dd>Distance measuring device</dd><dt>55</dt><dd>photodetector</dd><dt>57</dt><dd>Brightness control device</dd><dt>59</dt><dd>fully permeable section</dd><dt>61</dt><dd>fully reflecting section</dd><dt>63</dt><dd>partially reflecting / partially transparent portion</dd></dl>