JP3630879B2 - Video camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video camera having an imaging unit and a display unit connectable to the imaging unit .
[0002]
[Prior art]
Conventionally, this type of video camera (camera-integrated VTR) has a structure in which a normal imaging unit, an image display unit, and an image recording unit are integrated and cannot be separated. For this reason, for example, when attempting to shoot from a place out of reach, it is not possible to confirm the video to be taken.
[0003]
In order to solve the above problems, a video camera having the following configuration has been proposed. FIG. 7 is a block diagram showing the configuration of the video camera, in which a indicates an imaging unit and b indicates an image display recording unit.
[0004]
In the figure, 1 is a lens that captures a subject image, 2 is an image sensor that converts the captured subject image into an image signal, 3 is a CDS / AGC circuit that samples and holds the image signal to obtain an appropriate signal level, The analog image signal from the CDS / AGC circuit 3 is A / D converted into a digital image signal, and a digital signal processing circuit 5 performs predetermined digital signal processing. The digital signal signal from the digital signal processing circuit 4 is converted to the NTSC system. This is an NTSC encoder for converting to a video signal.
[0005]
Further, 6 is a cable connecting the image pickup unit a and the image display / recording unit b, 7 is a display monitor for displaying an image by the NTSC video signal reproduced from the image pickup unit a or the recording / reproducing unit 8, and 8 is from the image pickup unit a. Reference numeral 9 denotes a recording / reproducing unit for recording / reproducing the NTSC video signal, and 9 is an attaching / detaching unit for mechanically attaching / detaching the imaging unit a and the image display / recording unit b.
[0006]
In the above configuration, the image display / recording unit b can be separated from the imaging unit a, and the image display / recording unit b and the imaging unit a can be integrated and used as necessary. . Then, the image of the subject imaged by the imaging unit a can be displayed on the monitor screen of the display / recording unit b connected by the cable 6.
[0007]
[Problems to be solved by the invention]
However, in the conventional video camera as described above, a cable extends from the imaging unit to the display / recording unit, and this cable becomes an obstacle, and the degree of freedom during shooting is limited. There was a point.
[0008]
Further, in the video camera as described above, when the image display / recording unit is away from the imaging unit, the data transmission speed of the image transmission path is greatly limited, and the image display unit and the imaging unit are integrated. In such a state, the restriction on the data transmission speed of the image transmission path during that time becomes smaller.
[0009]
Therefore, when sending image data from the imaging unit to the image display unit, it is necessary to reduce the amount of image data in accordance with the limitation of the data transmission speed of the image transmission path when the image display / recording unit is away from the imaging unit. There is.
[0010]
However, since the image quality deteriorates due to the reduction of the image data, the image quality is reduced even when the data transmission speed is limited as in the case where the image display / recording unit and the imaging unit are integrated. Degradation will occur.
[0011]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a video camera with improved flexibility during shooting.
[0012]
The present invention also provides a video camera that can perform optimal image transmission even when the display unit is not connected to the imaging unit or when the display unit is connected to the imaging unit. The purpose is to do.
[0014]
[Means for Solving the Problems]
The video camera according to the present invention is a video camera having an imaging unit and a display unit connectable to the imaging unit, and when the display unit is connected to the imaging unit, the first compression method When the image compressed according to the method is transmitted from the imaging unit to the display unit and the display unit is not connected to the imaging unit, the second compression method having a higher compression ratio than the first compression method is used. The compressed image is wirelessly transmitted from the imaging unit to the display unit.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
(Example 1)
Example 1 of the present invention will be described with reference to the drawings.
[0030]
FIG. 1 is a block diagram showing a configuration of an imaging transmission unit A on the transmission side of the video camera (camera integrated VTR) according to the present embodiment. In the figure, 101 is a lens that captures a subject image, 102 is an image sensor that photoelectrically converts the captured subject image into an image signal, and 103 is a CDS that samples and holds the image signal from the image sensor 102 to obtain an appropriate signal level. / AGC circuit 104 is a digital signal processing circuit that performs A / D conversion of the analog image signal from CDS / AGC circuit 103 into a digital image signal and performs predetermined digital signal processing. An image compression circuit that compresses image data of a digital image signal, and the data compression rate can be arbitrarily changed.
[0031]
A communication protocol / compression control unit 107 controls the image compression circuit 105, and further converts the compressed image signal from the image compression circuit 105 into compressed image data suitable for transmission by a spread spectrum method to be described later. The signal switching device for switching the connection destination of the compressed image data from the communication protocol / compression control unit 106 to the spread spectrum transmission unit 108 or the signal connection device 111 in the attachment / detachment device 113 to be described later. It is a spread spectrum transmission part which transmits in this way.
[0032]
109 is a transmission antenna, 110 is a compression control / signal selection microcomputer (microcomputer) for controlling the image compression rate in the image compression circuit 105 and the operation of the signal switching device 107, and 111 is a reception side including the image display unit of FIG. The above-described signal connection device 112 for connecting the digital signal processing circuit 104 to the receiving side when combined with the receiving side, 112 is a combining detecting device for detecting the combining when combined with the receiving side including the image display unit. is there.
[0033]
FIG. 2 is a block diagram illustrating the configuration of the reception display unit B on the reception side according to this embodiment. In the figure, 201 is a receiving antenna, 202 is a spread spectrum receiving unit that receives image data transmitted from the above-described spread spectrum transmitting unit 108 and demodulates it into compressed image data, and 210 is a transmitting side including the above-described imaging unit. A signal connection device that is connected to the signal connection device 111 on the transmission side when combined, and is provided in an attachment / detachment device 212 that cooperates with the attachment / detachment device 113 of FIG.
[0034]
203 is a signal switching device for switching a connection source of a communication protocol / decompression control unit 205, which will be described later, to the spread spectrum reception unit 202 or the signal connection device 210, and 204 decompresses the compressed image data so as to decompress the original digital image before compression. An image decompression circuit for restoring the signal, 205 is the protocol / decompression controller for controlling the input / output of the compressed image data and the digital image signal, 207 is a D / A converter for the digital image signal to an analog image signal, and NTSC An NTSC encoder 208 for converting the video signal into a video signal is a display monitor that displays an image using the NTSC video signal.
[0035]
Further, reference numeral 209 denotes a signal selection microcomputer that controls the signal switching device 203 according to the detection result of the coalescence detection device 211 described later, 210 denotes a signal connection device in the detachable device 212, and 211 denotes a transmission side including the imaging unit. It is the above-mentioned uniting detection device that detects that the uniting sometimes.
[0036]
FIG. 3 is a diagram showing details of the image compression circuit 105 of FIG. In the figure, 301 is a raster-block transform unit, 302 is a DCT (discrete cosine transform) unit, 303 is a quantization unit, 304 is a Huffman coding unit, and 305 is given to a quantization block (quantization unit 303). A quantization table 306 is a Huffman table given to the Huffman coding block (Huffman coding unit 304).
[0037]
In the image compression circuit 105 configured as described above, the input digital image signal in the raster format is converted into a pixel block of 8 × 8 pixels by the raster-block conversion unit 301, and discrete cosine conversion is performed for each pixel by the DCT unit 302. Then, quantization and Huffman coding are performed based on the quantization table and Huffman table set by the compression control signal, and the compressed image signal is output.
[0038]
At this time, the compression rate of the image data amount can be changed by setting the quantization table.
[0039]
FIG. 4 is a diagram showing details of the image expansion circuit 204 in FIG. In the figure, 401 is a quantization table given to a quantization block (inverse quantization unit 404), 402 is a Huffman table given to a Huffman coding block (Huffman combination unit 403), 403 is a Huffman decoding unit, 404 Is an inverse quantization unit, 405 is an IDCT (Inverse Discrete Cosine Transform) unit, and 406 is a block-raster conversion unit.
[0040]
In the image expansion circuit 204 configured as described above, the input compressed image signal is subjected to Huffman decoding and dequantization based on the Huffman table and quantization table selected by the table information included in the compressed image signal. The IDCT unit 405 performs inverse discrete cosine transform, and the block-raster converter 406 returns the raster format to a digital image signal.
[0041]
Here, when the imaging transmission unit A in FIG. 1 and the reception display unit B in FIG. 2 are separated, the coalescence detection devices 112 and 211 do not detect the coalescence state, so that the transmission-side microcomputer 110 performs signal switching. The device 107 is instructed to connect the communication protocol / compression control unit 106 to the spread spectrum transmission unit 108, and the receiving-side microcomputer 209 connects the signal switching device 203 to the communication protocol unit 205 to the spread spectrum reception unit 202. I give an order to.
[0042]
Further, the microcomputer 110 instructs the quantization unit 303 of the image compression circuit 105 to use a quantization table that is highly compressed.
[0043]
The signal path at this time is as follows: lens 101 → image sensor 102 → CDS / AGC circuit 103 → digital signal processing circuit 104 → communication protocol / compression control unit 106 → image compression circuit 105 (high compression setting) → communication protocol / compression control unit 106 → spread spectrum transmission section 108 → transmission antenna 109 → reception antenna 201 → spread spectrum reception section 202 → communication protocol section 205 → image decompression circuit 204 → communication protocol section 205 → NTSC encoder 207 → display monitor 208
[0044]
In this state, the image captured on the transmission side including the imaging unit is highly compressed so as to be within the data transmission rate between the spread spectrum transmission and reception described above, and is compared with the reception side including the image display unit by spread spectrum. Wirelessly transmitted and displayed on the display monitor 208.
[0045]
In addition, when the imaging transmission unit A in FIG. 1 and the reception display unit B in FIG. 2 are combined and integrated, the transmission-side and reception-side combination detection devices 112 and 211 detect the combined state, The microcomputer 110 instructs the signal switching device 107 to connect the communication protocol / compression control unit 106 to the signal connection device 111, and the microcomputer 209 on the receiving side sends the communication protocol control unit 205 to the signal switching device 203. Command to connect to 210.
[0046]
Further, the microcomputer 110 instructs the quantization unit 303 of the image compression circuit 105 to use a quantization table with low compression.
[0047]
The signal path at this time is as follows: lens 101 → image sensor 102 → CDS / AGC circuit 103 → digital signal processing circuit 104 → communication protocol / compression control unit 106 → image compression circuit 105 (low compression setting) → communication protocol / compression control unit 106 → signal connection device 111 → signal connection device 210 → communication protocol unit 205 → NTSC encoding 207 → display monitor 208.
[0048]
In this state, the image captured on the transmission side including the imaging unit is low-compressed and then wired to the reception side including the image display unit by the signal connection device 107 and displayed on the display monitor 208. The
[0049]
As described above, in this embodiment, when the transmission side including the imaging unit and the reception side including the image display unit are separated, the image data is highly compressed, which is advantageous in wireless communication. In addition, when the transmission side including the imaging unit and the reception side including the image display unit are united and integrated, the image data is low-compressed, so that high-quality image transmission can be performed.
[0050]
At this time, a storage medium 206 for recording / reproducing an analog image signal may be connected between the NTSC encoder 206 and the display monitor 208 to record / reproduce an image.
[0051]
FIG. 5 is a flowchart showing the operation of the above-described embodiment, where (a) shows processing on the transmission side and (b) shows processing on the reception side. These processes are performed by the microcomputers 110 and 209, respectively.
[0052]
When the transmission-side microcomputer 110 does not detect the coalescence with the reception side (step Sa1), the connection destination of the communication protocol / compression control unit 106 is switched to the wireless spectrum spread spectrum transmission unit 108 (step Sa2). Then, the image data from the digital signal processing circuit 104 is input to the image compression circuit 105 (step Sa3), and after high compression processing (step Sa4), the compressed data is wirelessly transmitted to the receiving side (step Sa5).
[0053]
When the merge is detected in step Sa1, the connection destination of the communication protocol / compression control unit 106 is switched to the signal connection device 111 for wired transmission (step Sa6). Then, the image data from the digital signal processing circuit 104 is input to the image compression circuit 105 (step Sa7), subjected to low compression processing (step Sa8), and then the compressed data is wired and transmitted to the receiving side (step Sa9).
[0054]
On the other hand, when the microcomputer 209 on the receiving side does not detect the combination with the transmitting side (step Sb1), the connection source of the communication protocol / decompression control unit 205 is switched to the spread spectrum receiving unit 202 for wireless reception (step Sb2). The compressed image data is wirelessly received (step Sb3), and the data is decompressed and restored by the image decompression circuit 204 (step Sb4) and displayed on the monitor screen (step Sb5).
[0055]
When the merge is detected in step Sb1, the connection source of the communication protocol / decompression control unit 205 is switched to the wired signal connection device 210 (step Sb6). Then, the compressed image data is received by wire (step Sb7), and the data is decompressed and restored by the image decompression circuit 204 (step Sb8) and displayed on the monitor screen (step Sb9).
[0056]
In this way, the image of the photographed subject can be displayed on the monitor screen. However, in this embodiment, even when the imaging unit and the display unit are separated, there is no cable or the like between them. It will be big and easy to use.
[0057]
In addition, in a state where the imaging unit and the display unit are separated and combined, it is possible to perform optimal image transmission corresponding to each state.
[0058]
In this embodiment, when the image pickup unit and the display unit are combined, the image compression circuit 105 and the image expansion circuit 204 do not perform compression / decompression processing, and these circuits can be bypassed. It is.
[0059]
(Example 2)
A second embodiment of the present invention will be described with reference to the drawings. The transmission side including the imaging unit of the video camera of this embodiment is the same as the imaging transmission unit A in FIG.
[0060]
FIG. 6 is a block diagram showing the configuration of the reception display unit C of this embodiment. In the figure, reference numeral 501 denotes a receiving antenna, 502 denotes a spread spectrum receiving unit that receives image data transmitted from the spread spectrum transmitting unit 108 in FIG. 1 and demodulates it into compressed image data, and 503 denotes a communication protocol / decompression control unit described later. 505 is a signal switching device that switches the connection source of 505 to the signal spreader 512 in the spread spectrum receiver 502 or the detachable device 514.
[0061]
504 is an image expansion circuit that expands the compressed image data and returns it to a digital image signal, 505 the communication protocol control unit that controls input / output of the compressed image data and the digital image signal, and 506 the digital image signal. An NTSC encoder that performs D / A conversion to an analog image signal and converts it to an NTSC video signal, 507 is a display monitor that displays an image based on the NTSC video signal, and 508 is a low monitor for recording an image on a recording medium 510 to be described later. An image compression circuit for performing compression, 509, a recording source switching device for connecting the recording medium 510 to the image compression circuit 508 or the signal connection device 512 in conjunction with the signal switching device 503, and 510 for compressing the compressed digital image data. The above-mentioned digital recording medium for recording / reproducing.
[0062]
Reference numeral 511 denotes a signal selection microcomputer that controls the signal switching device 503 according to the detection result of the coalescence detection device 513, which will be described later. Reference numeral 512 denotes a signal connection device 111 on the transmission side when combined with the transmission side including the imaging unit in FIG. The above-mentioned signal connection device 513 connected is a coalescence detection device that detects that it is merged when it is combined with the transmission side including the above-described imaging unit.
[0063]
The configurations of the image compression circuit 508 and the image expansion circuit 504 are the same as those of the image compression circuit and the image expansion circuit in FIGS.
[0064]
In the above configuration, when the transmission side including the imaging unit in FIG. 1 and the reception side including the image display unit in FIG. 5 are separated, the combination detection devices 112 and 513 on the transmission side and the reception side do not detect the combined state. Therefore, the microcomputer 110 on the transmission side issues a command to the signal switching device 107 to connect the communication protocol / compression control unit 106 to the spread spectrum transmission unit 108, and the microcomputer 511 on the reception side sends the communication protocol unit 505 to the signal switching device 503. Is connected to the spread spectrum receiver 502. At this time, the recording source switching device 509 connects the recording medium 510 to the image compression circuit 508 in conjunction with the signal switching device 503.
[0065]
Further, the microcomputer 110 instructs the quantization unit 303 of the image compression circuit 105 to use a quantization table with high compression.
[0066]
The signal path at this time is as follows: lens 101 → image sensor 102 → CDS / AGC circuit 103 → digital signal processing circuit 104 → communication protocol / compression control unit 106 → image compression circuit 105 (high compression setting) → communication protocol / compression control unit 106 → spread spectrum transmission section 108 → transmission antenna 109 → reception antenna 501 → spread spectrum reception section 502 → communication protocol section 505 → image decompression circuit 504 → communication protocol control section 505 → NTSC encoder 506 → display monitor 507 Protocol control unit 505 → image compression circuit 508 → digital recording medium 510.
[0067]
In this state, the image captured on the transmission side including the imaging unit is highly compressed so as to be within the data transmission speed between the spread spectrum transmission and reception described above, and is compared with the reception side including the image display unit by spread spectrum. Wirelessly transmitted and displayed on the display monitor 507.
[0068]
Further, the digital image signal from the communication protocol control unit 505 is subjected to low compression processing by the image compression circuit 508 and recorded on the digital recording medium 510.
[0069]
In addition, when the transmission side including the imaging unit and the reception side including the image display unit are united and integrated, the combination detection devices 112 and 513 on the transmission side and the reception side detect the combination state, and the transmission side The microcomputer 110 instructs the signal switching device 107 to connect the communication protocol / compression control unit 106 to the signal connection device 111, and the receiving-side microcomputer 511 sends the communication protocol control unit 505 to the signal switching device 503. Command to connect to 512.
[0070]
At this time, the recording medium switching device 509 connects the recording medium 510 to the signal connection device 512 in conjunction with the signal switching device 503.
[0071]
Further, an instruction is issued to the quantization unit 303 shown in FIG. 3 of the image compression circuit 105 on the transmission side so as to use a quantization table for low compression.
[0072]
The signal path at this time is as follows: lens 101 → image sensor 102 → CDS / AGC circuit 103 → digital signal processing circuit 104 → communication protocol / compression control unit 106 → image compression circuit 105 (low compression setting) → communication protocol / compression control unit 106 → signal connection device 111 → signal connection device 512 → communication protocol unit 505 → image expansion circuit color 504 → communication protocol unit 505 → NTSC encoder 506 → display monitor 507, and signal connection device 512 → digital recording medium 510 → Become.
[0073]
In this state, the image captured on the transmission side including the imaging unit is low-compressed, and then wired to the reception side including the image display unit by the signal connection device 107 and displayed on the display monitor 507. The
[0074]
Further, the compressed image data subjected to low compression on the transmission side is directly recorded on the recording medium 510 through the signal connection device 512 without going through the image compression circuit 508 that performs the compression processing common to the low compression.
[0075]
As described above, in this embodiment, when the transmission side including the imaging unit and the reception side including the image display unit are separated, the image data is highly compressed, which is advantageous in wireless communication.
[0076]
In addition, when the transmission side including the imaging unit and the reception side including the image display unit are combined and integrated, the image data is low-compressed, so that high-quality image transmission can be performed. Further, at this time, the low-compressed image data from the transmission side is directly recorded on the recording medium 510 without being compressed again by the compression circuit on the reception side, so that deterioration in image quality can be reduced.
[0077]
In each of the above embodiments, since the compressed data is decompressed and converted into a standard television signal by the NTSC encoder, a free compression method can be selected as the compression method, and the compression efficiency can be increased. Further, it is not necessary to have a conversion circuit for converting a standard television signal such as an NTSC encoder on both the transmission side and the reception side.
[0078]
【The invention's effect】
According to the present invention, since the imaging unit and the display unit can be used separately, usability is improved. In addition, according to the present invention, it is possible to perform optimal image transmission even when the display unit is not connected to the imaging unit or when the display unit is connected to the imaging unit.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a transmission side according to a first embodiment. FIG. 2 is a block diagram illustrating a configuration of a reception side according to the first embodiment. FIG. 3 is a block diagram illustrating details of an image compression circuit. FIG. 5 is a flowchart showing the operation of the first embodiment. FIG. 6 is a block diagram showing the configuration of the receiving side of the second embodiment. FIG. 7 is a block diagram showing the configuration of the conventional example. Explanation of]
DESCRIPTION OF SYMBOLS 102 Image pick-up element 104 Digital signal processing circuit 105 Image compression circuit 106 Communication protocol / compression control part 107 Signal switching apparatus 108 Spread spectrum transmission part 109 Transmission antenna 110 Compression control / signal selection microcomputer 111 Signal connection apparatus 112 Combined detection apparatus 113 Attachment / detachment apparatus 201 Receiving antenna 202 Spread spectrum receiving unit 203 Signal switching device 204 Image expansion circuit 205 Communication protocol control unit 208 Display monitor 209 Signal selection microcomputer 210 Signal connecting device 211 Combined detection device 212 Attachment / detachment device 501 Receiving antenna 502 Spread spectrum receiving unit 503 Signal switching device 504 Image expansion circuit 505 Communication protocol control unit 507 Display monitor 508 Image compression circuit 509 Recording source switching device 510 Digital recording medium 511 Signal selection microcomputer 51 2 Signal connection device 513 Combined detection device 514 Detachment device

Claims (1)

A video camera having an imaging unit and a display unit connectable to the imaging unit,
When the display unit is connected to the imaging unit, an image compressed according to a first compression method is transmitted from the imaging unit to the display unit,
When the display unit is not connected to the imaging unit, the image compressed according to the second compression method having a higher compression rate than the first compression method is wirelessly transmitted from the imaging unit to the display unit. Features a video camera.

Images