VIDEO COMMUNICATIONS TERMINAL AND CONTROL CIRCUIT FOR THE TERMINAL

Abstract: According to the present invention, a controller (100) is such that, when an image is picked up with a camera (10) facing a display section (40) side corresponding to a user side, an instruction is given to a view angle switching processing section (20) to allow image pick-up data to become a wide angle shot data under a CIF format through partly cutting processing to effect a conversion to a QCIF format one and, when an image is picked up with the camera facing a side opposite to the user side, an instruction is given to allow image pick-up data to become a narrow angle shot data under a CIF format through partly cutting processing to effect a conversion to a QCIF one.

Description: D E S C R I P T I O N VIDEO COMMUNICATIONS TERMINAL AND CONTROL CIRCUIT FOR THE TERMINAL Technical Field The present invention relates to a video communications terminal, such as a portable telephone terminal having a TV phone function, capable of picking up an image and transmitting/receiving video data and a control circuit for the same. Background Art As well known, there is, as a terminal of a conventional mobile communications system, a terminal equipped with an electronic camera and having the function of transmitting a picked-up image to a communication party. Such a video communications terminal has a mechanism for rotating an image pick-up section, etc., and, by doing so, switching an image pick-up direction. In order to use it for the TV phone for instance, a different view angle is required between the case where an image is picked up with an image pick-up section facing a user side and the case where a snap shot is taken with the image pick-up section facing a side opposite to the user side while confirming a picked-up image on a display section. If, therefore, a picture is taken of the user with, for example, a horizontal view angle of 50° as a view angle suitable to a snap shot, then the user's face alone will be shot to a overly covered image range due to the user-to-camera distance being about 30 cm and, even if an image pick-up direction is slightly displaced, it is not possible to obtain a desired composition. That is, if a picture is taken on the conventional video communications terminal with the image pick-up direction of the image pick-up section switched, then an image is picked up at a not-desirable view angle depending upon a direction taken. Disclosure of Invention It is accordingly the object of the present invention to provide a video communications terminal capable of, even if an image is picked up with the image pick-up direction of an image pick-up section switched, picking up an image at a view angle desirable relative to that direction, and a control circuit for the video communications terminal. In order to achieve the above-mentioned object of the present invention, the video communications terminal according to the present invention and control circuit of the video communications terminal detect an image pick-up direction of an image pick-up means through an image pick-up direction detecting means and allow a view angle control means to switch an image pick-up view angle of image pick-up data obtained by the image pick-up means in accordance with a result of that detection. As a result, according to the video communication terminal thus structured and its control circuit, even if the user does not switch the image pick-up view angle in accordance with the image pick-up direction, the image pick-up view angle is switched in accordance with the image pick-up direction of the image pick-up means and it is, therefore, possible to pick up an image at a view angle suitable to the image pick-up direction. Brief Description of Drawings FIG. 1 is a circuit block diagram showing an arrangement of a video communications terminal according to one embodiment of the present invention; FIG. 2 shows an outer appearance of the video communications terminal shown in FIG. 1; FIG. 3 is a concept diagram for explaining wide angle conversion processing by a view angle conversion processing section of the video communications terminal shown in FIG. 1; FIG. 4 is a concept diagram for explaining narrow angle conversion processing by the view angle conversion processing section of the video communications terminal shown in FIG. 1; and FIG. 5 is a flow chart for explaining wide angle conversion control by the view angle conversion processing section of the video communications terminal shown in FIG. 1. Best Mode of Carrying Out the Invention One embodiment of the present invention will be explained below with reference to the accompanying drawings . FIG. 1 shows an arrangement of a video communications terminal according to one embodiment of the present invention. This video communications terminal includes a camera 10, view-angle switching processing section 20, image coding/decoding processing section 30, display section 40, camera direction detecting section 50, voice inputting/outputting section 60, radio communications section 70 having an antenna 71, keying- in section 80 and controller 100. The camera 10 is comprised of an electronic camera for picking up an image of a CIF format (352 horizontal * 288 vertical pixels) at a horizontal view angle of about 70° with the use of a single focus lens and data obtained by the picked up image is output to a view angle switching processing section 20. Further, the camera 10 is, as shown in FIG. 2 for instance, provided at an upper section of the video communications terminal and allows its image pick-up direction to be manually 180°-moved by a rotation mechanism in a non-stepped way and hence allows a picture taking to be obtained over a range from a display section 40 side as will be described below to a direction of a back surface opposite to the display section of the terminal. The view-angle switching processing section 20 allows wide angle processing or narrow angle processing to be selectively performed in response to an instruction from the controller to be later described and, by doing so, allows image picked-up data of the CIF format which is input by the camera 10 to be converted to a QCIF format (176 horizontal * 144 vertical pixels ) . The output of the switching processing section 20 is supplied to the image coding/decoding processing section 30. Of these processing, the wide angle processing allows pixel data to be extracted from a vertical * horizontal pixel array at every other pixel interval as shown in FIG. 3 and, by doing so, allows the video data of the CIF format to be converted to a QCIF format. It is to be noted that, in FIG. 3, the number of pixels is 48 vertical * 36 horizontal for simplification of the drawing. Further, the narrow angle processing allows pixel data to be extracted at a rate of two pixels for three pixels from pixel data (264 vertical * 216 horizontal) at a central section left by eliminating an outer peripheral section of the CIF format by 1/8 in vertical and horizontal directions as shown in FIG. 4 and, by doing so, allows the video data of a CIF format to be converted to data of a QCIF format. Even in FIG. 4, the number of pixels is 48 vertical * 36 horizontal. The image coding/decoding processing section 30 allows the video data of the QCIF format which comes from the view-angle switching processing section 20 to be output to the display section 40 as it is and the above-mentioned video data is subjected to coding processing so that it is output to the radio communications section 70. Further, the image coding/decoding processing section 30 decodes a signal coming from the radio communications section 70 via the antenna 71 and outputs it to the display section 40. The display section 40 is comprised of a liquid crystal panel, etc., to visually show the video data as a video to the user. The display section 40 shows a video taken by the camera 10 on the basis of the video data input from the image coding/decoding processing section 30, or, after a signal sent from a communication party has been decoded by the image coding/decoding processing section 30, the display section 40 receives it as video data and display it. The camera direction detecting section 50 detects the image pick-up direction of the camera 10 and the detected camera direction information is output to the controller 100. The voice inputting/outputting section 60 includes a microphone and speaker to allow a user ' s talking voice which is input from the microphone to be coded and output to a radio communications section 70 and allows talking voice data which comes from the communications party to be decoded and output from the speaker. In accordance with a predetermined communications protocol, the radio communications section 70 establishes a communication link relative to a communication party via a base station connectable to a public network to allow voice data and video data to be transmitted and received. The keying-in section 80 comprises various keys, such as ten keys and on-hook/off-hook key and provides a man-machine interface for receiving a user ' s request and instruction through the keying-in operation. The controller 100 includes, for example, a microcomputer as a main controller and is adapted to generally control each parts set out above to allow the video and voice communication to be conducted relative to the communication party. Further, the controller 100 has a view-angle switching control function as a new control function. This control function imparts an instruction for performing wide-angle processing or narrow-angle processing to the view-angle switching processing section 20 in accordance with camera direction information given from the camera direction detecting section 50. Now an explanation will be given below about the view-angle switching processing of the vide communications terminal of a structure set out above. FIG. 5 is a flow chart of this processing done by the controller 100. First, at step 5a, camera direction information is received from the camera direction detecting section 50 and control goes to step 5b. At step 5f it is decided, by the camera direction information obtained by step 5a, whether the camera 10 faces a display section 40 side or an opposite back side. If the camera faces the display section 40 side, then control goes to step 5c. If, on the other hand, the camera faces the opposite back side, then control goes to step 5d. At step 5c, an instruction for performing the wide-angle processing is imparted to the view-angle switching processing section 20. At step 5d, an instruction for performing the narrow angle processing is imparted to the view-angle switching processing section 20. The video communications terminal is such that, when the user gives an instruction to pick up an image, by such processing, with the camera facing the display section 40 side for example, then the controller 100 imparts an instruction for performing the wide-angle processing to the view-angle switching processing section 20. By doing so, picked-up image data of a CIF format is subjected by the view-angle switching processing section 20 to wide angle processing to provide data of a QCIF format and it is possible to obtain video data taken at a horizontal view angle of about 70°. The video data is output to the display section 40 where it is displayed as it is . And the video data is subjected by the image coding/decoding processing section 30 to coding processing and then transmitted via the radio communications section 70 to a communication party. hen, on the other hand, the user gives an instruction to pick up an image with the camera facing a back side opposite to the display section 40 side, the controller 100 instructs the view-angle switching processing section 20 to perform narrow-angle processing. By doing so, picked-up image data of a CIF format is subjected by the view-angle switching processing section 20 to narrow angle processing to provide picked-up image data of a QCIF format and it is possible to obtain image data taken at a horizontal view angle of about 50°. The picked up image data is output to the display section 40 and displayed as it is. On the other hand, it is, after being subjected by the image coding/ decoding processing section 30 to coding processing, transmitted via the radio communications section 70 to a communication party. In the video communications terminal thus structured, as set out above, when an image is picked up with the camera facing the display section 40 side corresponding to the user side, a wide angle shot is carried out. When, on the other side, an image is picked up with the camera 10 facing the back side opposite to the user side, a narrow angle shot is carried out. That is, an image pick-up angle is switched in accordance with an image pick-up direction of the camera 10. According to the video communications terminal thus structured, therefore, even if the user does not switch the image pick-up view angle, it is possible to switch the image pick-up view angle in accordance with the image pick-up direction of the camera and hence to pick up an image in a way suited to the image pick-up direction. The present invention is not restricted to the above-mentioned embodiment. Although, in the above-mentioned embodiment, the range over which partly cutting processing is performed on the data initially picked up at the wide angle with the use of many pixels is made variable, it may be possible that, for example, a camera is equipped with a zoom lens to allow an image pick-up view angle to be made variable and, by doing so, the zoom lens has its driving controlled in accordance with the direction of * * the camera 10 to allow the image pick-up view angle to be variably controlled. This also obtains the same advantage. Although, in the above-mentioned embodiment, the controller 100 imparts a view angle switching instruction to the view angle switching processing section 20 in accordance with a detection result of the camera direction detecting section 50, it may be possible that, insteads, a result of detection of the camera direction detecting section 50 is directly input to the view angle switching processing section 20 to allow a view angle switching to be done based on the detection result. Although, in the above-mentioned embodiment, the partly cutting rate of the partly cutting processing is set to be 1/2 and 2/3, it may be set to be 3/4 so that it is possible to obtain an image picked up at a still narrower angle. Still further, the partly cutting rate can be made to allow any given image pick-up view angle to be set in accordance with the image pick-up direction and this is done so by receiving a change request from the user through the keying input section 80. Table 1 shows a relation of a focal length f calculated in terms of that of a 35 mm film camera to the horizontal view angle. According to the Table 1, the horizontal view angle of 52° corresponds to a focal length f = 37 mm. However, a focal length fitted to a snap short on the 35 mm film camera is generally about 35 mm to 38 mm and it is found that the horizontal view angle of 52° is a view angle suitable to the snap shot. Various changes or modifications of the present invention can be made without departing from the spirit and scope of the present invention. Table 1 to

Claims: C L A I M S 1. A video communications terminal for communicating to a communication party with the use of video data, characterized by comprising: image pick-up means for picking up an image with an image pick-up direction switched; image pick-up direction detecting means for detecting the image pick-up direction of the image pick-up means ; and view angle control means for switching an image pick-up view angle of video data obtained by the image pick-up means in accordance with the image pick-up direction detected by the image pick-up direction detecting means. 2. A video communications terminal according to claim 1, characterized in that said view angle control means applies extraction processing, at a predetermined rate, on pixel data constituting the image pick-up data obtained by the image pick-up means to extract pixel data and generate new image pick-up data and switches the image pick-up view angle of the image pick-up data obtained by said image pick-up means. 3. A video communications terminal according to claim 2, characterized in that said view angle control means is such that, when the image pick-up view angle is to be set to a wide angle, pixel data is extracted, as the extraction processing, at a predetermined rate from a whole array of pixel data constituting image pick-up data obtained by the image pick-up means and, when the image pick-up view angle is to be set to a narrow angle, pixel data is extracted, as the extraction processing, at a predetermined rate from a central area of an array of pixel data constituting image pick-up data obtained by the image pick-up means . 4. A video communications terminal according to any one of claims 1 to 3 , characterized in that said image angle control means is such that, when an image pick-up direction detected by said image pick-up direction detecting means is toward a user side, control is effected to allow an image pick-up view angle to be set to a wide angle and, when an image pick-up direction detected by the image pick-up direction detecting means is toward other than the user side, control is effected to allow an image pick-up view angle to be set to a narrow angle. 5. A video communications terminal according to any of claims 1 to 4, characterized by further comprising display means for displaying the image pickup data controlled by said view angle control means with respect to the view angle and video data received from the communication party. 6. A control circuit of a video communications terminal equipped with image pick-up means for picking up an image with an image pick-up direction switched and for communicating to a communication party with the use of video data, characterized by comprising: image pick-up direction detecting means for detecting an image pick-up direction of the image pick- up means; and view angle control means for switching an image pick-up view angle of image pick-up data obtained by the image pick-up means in accordance with the image pick-up direction detected by the image pick-up direction detecting means. 7. A control circuit of a video communications terminal according to claim 6, characterized in that said view angle control means is such that extraction processing is performed, at a predetermined rate, on pixel data constituting image pick-up data obtained by said image pick-up means to extract pixel data and generate new image pick-up data an image pick-up view angle of the image pick-up data obtained by the image pick-up means is switched. 8. A control circuit of a video communications terminal according to claim 7, characterized in that said view angle control means is such that, when an image pick-up view angle is to be set to a wide angle, pixel data is extracted, as the extraction processing, at a predetermined rate from a whole array of pixel data constituting image pick-up data obtained by the image pick-up means and, when the image pick-up view angle is to be set to a narrow angle, pixel data is extracted, as the extraction processing, at a predetermined rate from a central area of an array of pixel data constituting image pick-up data obtained by the image pick-up means. 9. A control circuit of a video communications terminal according to any of claims 6 to 8, characterized in that said view angle control means is such that, when an image pick-up direction detected by said image pick-up direction detecting means is toward a user, control is effected to allow an image pick-up view angle to be set to a wide angle and, when an image pick-up direction detected by the image pick-up direction detecting means is toward other than the user side, control is effected as to allow an image pick-up view angle to be set to a narrow angle. 10. A control circuit of a video communications terminal according to any of claims 6 to 9, characterized by further comprising display means for displaying image pick-up data controlled by said view angle control means with respect to the view angle and video data received from a communication party.

Inventors: YAMAMOTO TOSHIFUMI, YAMAMOTO, TOSHIFUMI
Applicants: TOKYO SHIBAURA ELECTRIC CO, YAMAMOTO TOSHIFUMI, KABUSHIKI KAISHA TOSHIBA, YAMAMOTO, TOSHIFUMI
Application year: 2000
Main classification: H04N7
IPC codes: H04N5, H04N7