JPH1175118A - Video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the video camera provided with a sequential scanning CCD to attain low magnification of a dynamic range extension and to select a substantial sequential scanning mode or a dynamic range extension mode. SOLUTION: In the video camera 11 , a 1st switch 12 is used to separate a long time exposure signal and a short time exposure signal outputted from a sequential scanning CCD 11. A delay means 13 delays the long time exposure signal by an exposure time of the short time exposure signal. Scanning conversion means 15, 16 each outputs each one line of the long time exposure signal and the short time exposure signal over one horizontal scanning period. A signal synthesis means 18 synthesizes each outputted exposure signal. A signal adder means 171 adds the long time exposure signals adjacent in a vertical direction in the unit of pixels depending on the sequential scanning mode. A switch 19 selects an output of the synthesis means 18 in the dynamic range extension mode or an output of the adder means 171 in the sequential scanning mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a video camera capable of expanding a dynamic range of a video movie or the like and performing progressive scanning output.

[0002]

2. Description of the Related Art Conventionally, two signals having different exposure amounts are synthesized to expand a dynamic range,
A video camera for obtaining a video signal having an excellent / N ratio is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 6-113207.

Hereinafter, this type of conventional video camera will be described with reference to FIGS. 9 and 10. FIG.

[0004] This video camera, as shown in FIG.
Imaging lens 10, progressive scanning CCD 11, switch 12,
It comprises a signal synthesizing unit 18 and a camera signal processing unit 20.

[0005] As shown in FIG. 10, the progressive scan CCD 11 includes a photoelectric conversion unit 50, a vertical transfer unit 52 for vertically transferring each charge transferred from the photoelectric conversion unit 50, and a vertical transfer unit 52. The horizontal transfer unit 54 serially outputs the transferred charges in the horizontal direction, and an output amplifier 56 that amplifies the output of the horizontal transfer unit 54.

The photoelectric conversion unit 50 has a number of photodiodes 51 corresponding to the number of pixels, and the vertical transfer unit 52 has C photodiodes corresponding to the respective photodiodes 51.
The CDs 53 are individually arranged in tandem.

Although FIG. 9 schematically shows a case where the number of pixels is 4 pixels by 6 pixels, the actual number of pixels is, for example, that of a VGA (Video Graphics Array). , 640 horizontal pixels × 484 vertical pixels.

In the video camera having this configuration, the incident light that has entered through the imaging lens 21 is sequentially scanned by the CCD 22.
Is subjected to photoelectric conversion.

That is, in this progressive scanning CCD 11, as shown in FIG. 11, one field period (1 V)
The exposure time is switched between T ₁ ′ and T ₂ ′ using an electronic shutter (not shown) so that the amount of exposure to the photoelectric conversion unit 50 is different.

In this case, in the prior art, the exposure times T ₁ ′ and T ₂ ′ on the long and short sides are respectively T ₁ ′ = 1/6.
0 seconds and T ₂ ′ = 1/1000 seconds. Then, an image for one screen is captured during each of the exposure times T ₁ ′ and T ₂ ′. In the following, a signal obtained based on long-time exposure is referred to as Slnog, and a signal obtained based on short-time exposure is referred to as Sshort.

Each photodiode 51 of the photoelectric conversion unit 50
In the vertical blanking period, the outputs of the adjacent upper and lower photodiodes 51 are read out to the vertical transfer unit 52 as shown by arrows in FIG. Respectively.
Therefore, in the vertical transfer unit 52, Slong is placed at the position of the CCD 53 shown by a black circle, and C
S shorts are alternately accumulated at the position of the CD 53.

Each S stored in the vertical transfer unit 52
lnog and Sshort are the horizontal transfer units 5 alternately one line at a time.
4 and output via the output amplifier 56. Therefore, for example, when the progressive scanning CCD 11 is composed of 484 pixels in the vertical direction, 242 lines of Slnog and 242 lines of Sshort are output within one field period (1 V).

In this manner, Slnog and Sshort serially output from the progressive scanning CCD 11 alternately one line at a time.
Are separated into Slong and Sshort by the switch 12, and then synthesized by the signal synthesizing means 18 to be output as one system signal. Therefore, in the case of the interlace method, in the above example, the period of one field
A combined signal Smix for 242 lines is obtained within (1V).

Here, as shown in FIG.
ng saturates at the incident light amount indicated by the symbol L ₁ ′ due to the large exposure amount, but at a smaller incident light amount, the signal level changes greatly. Has been saved. On the other hand, in Sshort, although the gradation is low in the low luminance portion due to a small amount of exposure, the gradation is preserved without saturation to the high luminance portion. For this reason, since the gradation characteristics of the signal Smix obtained by combining the two are expanded more than the gradation characteristics of only Slong, the apparent dynamic range is expanded.

The synthesized signal Smix whose dynamic range has been expanded in this way is supplied to the camera signal processing means 2 at the next stage.
At 0, the video signal is processed and output to a video signal suitable for TV display (for example, NTSC system).

[0016]

The conventional video camera of this type has the following problems (1) and (2).

(1) As described above, conventionally, the Slong exposure time T ₁ ′ = 1/60 second and the Sshort exposure time T ₂ ′ = 1
/ 1000 seconds, but in this case, the magnification of the dynamic range (= θl ′ / θs ′) is about 16 times [≒ (1
/ 60) / (1/1000)].

However, if the exposure time T ₂ ′ for Sshort is extremely short, such as 1/1000 second, the S / N of Sshort itself is insufficient and the gradation is insufficient. is there.

For this reason, in FIG. 12, for example, when the amount of incident light is in the range of L ₁ ′ to L ₂ ′, the signal level of S short is still low even though Slnog is saturated. As a result, the N ratio becomes poor, and as a result, the synthesized signal Smix is greatly influenced by noise components, and a good display image cannot be obtained.

Therefore, as a practical magnification of the dynamic range, a low magnification of, for example, about 2 to 4 times is required instead of a high magnification as in the related art.

(2) In the conventional configuration, when the progressive scanning CCD 11 is used for expanding the dynamic range as described above, the original purpose of the progressive scanning CCD 11, that is, the progressive scanning output ( In particular, it was not possible to obtain an output with enhanced image quality by emphasizing the vertical high frequency range.

That is, in the above example, the progressive scanning CCD 11 outputs Slnog for 242 lines and Sshort for 242 lines in one field period in the above-described example. The signals are combined, and eventually, a combined signal Smix for 242 lines
I can only get it. For this reason, it has not been possible to apply, for example, printing out a high-quality image of 484 lines by non-interlace.

SUMMARY OF THE INVENTION In view of the above problems, the present invention realizes a low dynamic range expansion in a video camera, and can selectively use an original progressive scanning mode and a dynamic range expansion mode as necessary. The task is to do so.

[0024]

In order to solve this problem, the present invention relates to a progressive scanning CCD and a progressive scanning CCD.
The following configuration is adopted in a video camera provided with a camera signal processing unit for converting the output of the above into a video signal suitable for image display.

That is, according to the first aspect of the present invention, when the exposure amount is changed according to the dynamic range expansion mode, a long exposure signal and a short exposure signal output from the progressive scanning CCD are separated. One switch, delay means for delaying the long-time exposure signal by the exposure time of the short-time exposure signal, and a time corresponding to one horizontal scanning period for each one line of the long-time exposure signal and the short-time exposure signal The first to scan convert to be output over
A second scanning conversion unit, a signal synthesizing unit for synthesizing a long exposure signal and a short exposure signal which are scan-converted and output by the first and second scanning conversion units to generate a synthesized signal; A signal adding unit that adds long-time exposure signals of two lines adjacent in the vertical direction to each other in pixel units according to the sequential scanning mode; an output of the signal combining unit in the dynamic range expansion mode; A second switch for selecting an output of the signal adding means and supplying the selected signal to the camera signal processing unit, wherein a dynamic range expansion mode and a sequential scanning mode are selectable.

With this configuration, it is possible to realize a dynamic range expansion of a low magnification such as 2 times and to obtain a sequential scanning output by switching.

[0027]

According to the first aspect of the present invention, a long-time exposure signal and a short-time exposure signal output from the progressive scanning CCD when the exposure amount is varied according to the dynamic range expansion mode are separated. A first switch to
Delay means for delaying the long-time exposure signal by the exposure time of the short-time exposure signal; and outputting one line of the long-time exposure signal and one line of the short-time exposure signal over a time corresponding to one horizontal scanning period. First and second scan conversion
A signal synthesizing means for synthesizing a long-time exposure signal and a short-time exposure signal which are scan-converted and output by the first and second scan-conversion means to generate a synthesized signal; A signal adding unit that adds long-time exposure signals for two lines that are vertically adjacent to each other in pixel units according to a scanning mode; an output of the signal combining unit in a dynamic range expansion mode; A second switch for selecting an output of the adding means and supplying the selected output to the camera signal processing unit, and configured to be able to select a dynamic range expansion mode and a sequential scanning mode.

According to a second aspect of the present invention, in the configuration of the first aspect, the first scan conversion means is also used as a delay element for delaying a long exposure signal by one horizontal scanning period in accordance with a sequential scanning mode. The long-time exposure signals before and after passing through the first scan conversion means are both inputted to the signal addition means.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the vertical high frequency band is determined based on a long-time exposure signal for at least three vertically adjacent lines in accordance with the sequential scanning mode. A vertical high-frequency emphasizing means for extracting an emphasis component is provided.

According to a fourth aspect of the present invention, in the configuration of the third aspect, both the first and second scan conversion means delay the long-time exposure signal by one horizontal scanning period in accordance with the sequential scanning mode. The present invention is also characterized in that it is also used as a delay element, and that long-time exposure signals before and after passing through the first and second scan conversion means are both input to the vertical high frequency emphasis means.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the first and second scan conversion means are provided with:
Further, at least one 1H delay element for delaying the long exposure signal by one horizontal scanning period is added, and the long exposure signal before and after passing through the 1H delay element is input to the vertical high frequency emphasizing means. It is characterized by comprising.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a video camera according to Embodiment 1 of the present invention.
Portions corresponding to the conventional example in FIG. 8 are denoted by the same reference numerals.

The video camera 1 ₁ of the first embodiment, the imaging lens 10, progressive scan CCD 11, the first switch 1
2. delay means 13, first and second scan conversion means 1
5, 16, a signal adding means 17 ₁ , a signal synthesizing means 18, a second switch 19, and a camera signal processing unit 20.

Here, it is assumed that the progressive scanning CCD 11 is composed of 484 pixels in the vertical direction for easy understanding. However, the present invention is not limited to such a number of pixels.

When the mode for enlarging the dynamic range is selected, the progressive scanning CCD 11 operates as shown in FIG.
As shown in FIG. 5, within one field period (1 V), the exposure time is switched between T ₁ and T ₂ using an electronic shutter or the like (not shown) so that the exposure amount to the photoelectric conversion unit 50 is different. It is configured.

The exposure times T ₁ and T _{2 in} this case are different from the conventional ones. Here, T ₁ = 1/90 seconds and T ₂ = 1/1
It is set to about 80 seconds. That is, sufficiently longer than the conventional exposure time T ₂ of the order to obtain the _{Sshort (T 2 >> T 2 '} )
It is set to be. Then, in the dynamic range expansion mode, as in the conventional case (see FIG. 10), Slnogs output from the upper and lower photodiodes 51 adjacent to the photoelectric conversion unit 50 and Sshorts are output from the CCDs 53 of the vertical transfer unit 52, respectively. Each is added.

Here, T ₁ = 1/90 seconds, T ₂ =
Although set to 1/180 second, the present invention is not limited to this, and T ₁ and T ₂ can be appropriately set according to the expansion ratio of the dynamic range. In the case of the first embodiment, the photoelectric conversion unit 50 to the vertical transfer unit 52
The timing of reading Slnog is not in the conventional vertical blanking period, but in the middle of one field period (1 V). Therefore, the transfer operation in the horizontal transfer unit 54 is temporarily stopped when reading Slnog from the photoelectric conversion unit 50 to the vertical transfer unit 52 so that the influence is not exerted.

Further, when the sequential scanning mode is selected, the sequential scanning CCD 11 does not switch the exposure time between long and short, and the photoelectric conversion unit 50 controls one screen period in one field period (1V). An image is taken to obtain Slnog, and this is read out to each CCD 53 individually corresponding to each photodiode 51. Therefore,
Unlike in the dynamic range expansion mode, the outputs of the adjacent upper and lower photodiodes 51 are not added. For this reason, in the progressive scanning mode, 484 lines of Slnog signal charges are accumulated in the vertical transfer unit 52.

The first switch 12 is connected to the progressive scanning CCD 11
Is selected and separated and output.

The delay means 13 delays Slnog selected by the first switch 12 by a predetermined time T ₂ (= 1/180 second) in order to match the phase at the end of transfer of Sshort.

First and second scan conversion means 15, 1
6 is a horizontal scanning period for each line of Slnog and Sshort.
This is for adjusting the output so as to be output over a time corresponding to (1H), and is constituted by, for example, a dual-port memory capable of independently controlling the writing speed and the reading speed.

In the dynamic range expansion mode, the reading speed is controlled to be half the writing speed, and when the sequential scanning mode is selected, the reading speed is controlled to be the same as the writing speed. You.

The signal synthesizing means 18 synthesizes Slnog and Sshort and outputs the synthesized signal Smix as one system.

The signal adding means 17 ₁ is intended to be used in the case of progressive scan mode, it adds both captures before and after Slnog the first scanning conversion means 15. This corresponds to adding Slnog of each pixel adjacent to each other in the vertical direction.

The second switch 19 selects the output of the signal synthesizing means 18 in the dynamic range expansion mode,
In which it is switched so as to select the output of the signal summing means 17 ₁ in sequential scan mode.

Next, operations of the above configuration in the dynamic range expansion mode and the sequential scanning mode will be described.

(1) Dynamic Range Expansion Mode When this mode is selected, a controller (not shown) switches the second switch 19 to select the output of the signal synthesizing means 18.

On the other hand, the incident light that has passed through the image pickup lens 10 is photoelectrically converted by the sequential scanning CCD 11 to be Slnog, Ssh.
ort is output.

That is, in the progressive scanning CCD 22, as shown in FIG. 2, the exposure times T ₁ (= 1/90 second) and T ₂ (= 1/180 second) are set within one field period (1 V).
Second) and the exposure time T ₁ ,
Image for one screen is respectively imaged during T _2.

Each photodiode 51 of the photoelectric conversion unit 50
Slnog obtained by photoelectric conversion in the at the end of one of the exposure time T ₁ of the 2, also, Sshort is at the end of the other exposure time T _2, are read out to the vertical transfer unit 52, The outputs of the adjacent upper and lower photodiodes 51 are added together. Therefore, Slnog and Sshort are alternately accumulated in the vertical transfer unit 52 in the vertical direction.

Each S stored in the vertical transfer unit 52
lnog and Sshort are the horizontal transfer units 5 alternately one line at a time.
4 and output via the output amplifier 56.

Therefore, when the progressive scanning CCD 11 is composed of 484 pixels in the vertical direction as in this example, as shown in FIG. 3, Slnog is equivalent to 242 lines within one field period (1 V). Similarly, Sshort is output for 242 lines, respectively, but the output timings of Slnog and Sshort are shifted by the period of exposure time T ₂ (= 1/180 second).
There is output ahead by T ₂ than Sshort).

In this manner, Slnog and Sshort which are serially output from the progressive scan CCD 22 alternately one line at a time.
Are separated from each other in a first switch 12, one Slnog is delayed by time of the T ₂ delay unit 13, the first scanning conversion means 15, also other Sshort
Are input to the second scan conversion means 16 as they are.

In each of the scan conversion means 15 and 16, Slnog and Sshort stored in units of one line correspond to one half of the writing speed so as to correspond to one horizontal scanning period (1H) under the interlace method. After being read out at the readout speed of
lnog and Sshort are synthesized in the same manner as before. Therefore, in the case of the interlace method, a combined signal Smix for 242 lines can be obtained within one vertical scanning period.

Here, in this example, the exposure time T _{1 of} Slong is used.
Since the exposure time T _{2 of} Sshort is set to 1/180 second, the enlargement ratio (= θl / θs) of the dynamic range in this case is about twice [≒ (1/90). / (1/1
80)].

As described above, since the exposure time T ₂ for S short is secured sufficiently longer than in the prior art,
S / N of rt itself is good, and sufficient gradation is obtained.

For this reason, in FIG. 4, for example, when the amount of incident light is in the range of L _{1 to} L ₂ , Slnog is saturated, but the signal level of S short is large, so that it is smaller than the conventional one (see FIG. 12). , S / N ratio is improved, and as a result,
The synthesized signal Smix is also less affected by the noise component, and a good display image can be obtained.

The combined output Smix from the signal combining means 18
Is supplied to the camera signal processing unit 20 via the second switch 19, subjected to predetermined signal processing, and output.

(2) When the Sequential Scan Mode is Selected When this mode is selected, the second switch 19 is controlled by the controller (not shown) by the signal adding means 17.
Switch to select ₁ output.

On the other hand, the incident light that has passed through the imaging lens 10 is photoelectrically converted in the sequential scanning CCD 11.

In this progressive scanning mode, the exposure time is not switched between long and short, and one field period (1 V) is used.
The image for one screen is picked up to obtain Slnog, and this is read out to each CCD 53 corresponding to each photodiode 51 individually.
The signal charge of lnog is accumulated, and the adjacent upper and lower photodiodes 5 are used as in the dynamic range expansion mode.
The outputs of 1 are not added.

[0063] Thus, Slnog output are sequentially scanned from sequential scanning CCD22 by one line, after being input delayed by the time T ₂ to the first switch 12 the delay unit 13 through the first Is input to the scan conversion means 15.

In the progressive scan mode, the first scan conversion means 15 delays one horizontal scanning period (1H).
Acts as an H delay element. That is, Slnog stored in units of one line is 1 in the non-interlace system.
By reading at the same reading speed as the writing speed so as to correspond to the horizontal scanning period (1H), 1
The output is delayed by the horizontal scanning period (1H).

Slnog for one line before being input to the first scan conversion means 15 and S for one line delayed by one horizontal scanning period (1H) by the first scan conversion means 15.
lnog is input to the signal adding means 17, respectively.

[0066] signal adding means 17 ₁ adds together Slnog of two lines vertically adjacent pixel by pixel. By this signal addition, in the camera signal processing unit 20 at the subsequent stage, the same processing as that for processing the signal obtained by adding the charges on the CCD 53 can be performed as in the related art.

[0067] The output of the signal summing means 17 ₁ is input to the camera signal processing 20 via a second switch 19, and output as a scanning signal for non-interlaced is subjected to predetermined signal processing.

The delay means 13 and the first scan conversion means 1
It is also possible to realize an interlace process by providing a switch between 5 and selecting and outputting Slnog of the CCD 11 in two fields.

(Embodiment 2) FIG. 5 is a block diagram showing a configuration of a video camera according to Embodiment 2 of the present invention.
Parts corresponding to the first embodiment shown in FIG. 1 are denoted by the same reference numerals.

[0070] The feature of this embodiment 2 of the video camera 1 _2, by the configuration of the second embodiment shown in FIG. 1, further switch 23, and the vertical high frequency emphasizing means 24 ₂ is added respectively is there.

That is, the third switch 23 selects and outputs the Sshort selected by the first switch 12 in the dynamic range expansion mode, and selects the Sshort output from the first scan conversion means 15 in the progressive scan mode. It is switched so that the data is output.

[0072] Further, the vertical high frequency emphasizing means 24 ₂ is for extracting a vertical high frequency emphasizing component based on the vertical direction of the front and rear third lines Slnog, as shown in FIG. 6,
An adder 30 for adding Slnog output from the delay means 13 and Slnog delayed and output by the second scan conversion means 16; an attenuator 31 for attenuating the output of the adder 30 to a half level; It comprises a subtractor 32 for subtracting the output of the attenuator 31 from the output Slnog delayed by the first scan conversion means, and an output amplifier 33 for gain adjustment.

The other structure is the same as that of the first embodiment shown in FIG.
In this case, the detailed description is omitted here.

Next, the operation of the above configuration will be described.

(1) In the dynamic range expansion mode When this mode is selected, the controller (not shown) switches the second switch 19 to the signal synthesizing means 18.
And the third switch 23
Switching is performed so that Sshort from the first switch 12 is selected.

The basic operation until a composite signal Smix is obtained based on Slnog and Sshort output from the progressive scanning CCD 11 is the same as in the first embodiment, and a description thereof will be omitted.

(2) When the Sequential Scan Mode is Selected When this mode is selected, the second switch 19 is controlled by the controller (not shown) by the signal adding means 17.
₁ and the third switch 23 selects Slnog from the first scan conversion means 15,
Each can be switched.

Then, the first and second scan conversion means 1
Each of the elements 5 and 16 functions as a 1H delay element that delays by one horizontal scanning period (1H).

[0079] Thus, the vertical high frequency emphasizing means 24 _2, Slnog output from the delay unit 13, Slnog is 1H delayed by the first scanning conversion means 15, the first scanning conversion means 15 and the third switch 23 As described above, the three signals of Slnog further delayed by 1H by the second scan conversion means 15, that is, Slnog of three vertically adjacent lines are input together.

[0080] vertical high frequency emphasizing means 24 _2, the adder 3
0, Slnog output from the delay means 13 and Slnog output delayed by the second scan conversion means 16 are added, and the adder 30 is added to the next isolator 30.
Is attenuated to レ ベ ル level, followed by a subtractor 32
By subtracting the output of the attenuator 31 and the Slnog delayed and output by the first scan conversion means 15,
The vertical high-frequency emphasis component is extracted, and the signal is output to the output amplifier 3
This signal is output after the gain has been adjusted at 3.

[0081] Then, signals of the vertical high-frequency emphasizing component extracted by the vertical high-frequency emphasizing means 24 _2, Slnog output from the delay unit 13, Slnog together which is 1H delayed by the first scanning conversion means 15, It is given to the signal adding means 17 _2.

[0082] The signal adding means 17 ₂ sequentially scans CCD1
After adding Slnog of two adjacent lines in the vertical direction on a pixel-by-pixel basis, and further adding a vertical high-frequency emphasis component thereto, the signal is input to the camera signal processing unit 20 via the third switch 19, and , And output as a non-interlaced scanning signal.

[0083] Thus, in the embodiment 2, the signal output from the signal adding means 17 _2, because they are high-frequency emphasis in the vertical direction, as compared with the case of Embodiment 1, avoiding horizontal stripes occur As a result, a higher resolution in the vertical direction can be achieved.

(Embodiment 3) FIG. 7 is a block diagram showing a configuration of a video camera according to Embodiment 3 of the present invention.
Portions corresponding to the second embodiment shown in FIG. 5 are denoted by the same reference numerals.

The feature of the video camera 13 of the _third embodiment is that the configuration of the second embodiment shown in FIG.
H memory 25 is added.
₃ is that it is configured as shown in FIG.

That is, in the above-described second embodiment, the vertical high-frequency emphasis component is extracted based on Slnog of three vertically adjacent lines. In the third embodiment, however, four vertically adjacent four-line emphasized components are extracted. That is, a vertical high-frequency emphasis component is extracted based on Slnog for the line.

The 1H memory 25 is for delaying Slnog for one line by one horizontal scanning period (1H).

[0088] Further, the vertical high frequency emphasizing means 24 _3, the first adder 35 for adding the Slnog output is delayed by Slnog and 1H memory 25 that is output from the delay unit 13, the first scanning conversion means 15 A second adder for adding Slnog delayed and output by the second adder and Slnog delayed and output by the second scan conversion means 16, and outputs the first
A subtractor 37 for subtracting the output of the adder 35;
Attenuator 3 for attenuating the output of 9 to 1/2 level
9 and an output amplifier 40 for gain adjustment.

The other structure is the same as that of the second embodiment shown in FIG.
In this case, the detailed description is omitted here.

Next, the operation of the above configuration will be described.

(1) At the time of dynamic range expansion mode When this mode is selected, the controller (not shown) switches the second switch 19 to the signal synthesizing means 18.
And the third switch 23
Switching is performed so as to select Sshort output from the first switch 12.

The basic operation until a composite signal Smix is obtained based on Slnog and Sshort output from the progressive scanning CCD 11 is the same as that of the first embodiment, and a description thereof will be omitted.

(2) When the Sequential Scan Mode is Selected When this mode is selected, the second switch 19 is controlled by the controller (not shown) by the signal adding means 17.
_In order to select the _first output, the third switch 23
Are switched so as to select Slnog from the first scan conversion means 15, respectively.

As in the case of the second embodiment, each of the first and second scan conversion means 15 and 16 functions as a 1H delay element that delays by one horizontal scanning period (1H).

[0095] Thus, the vertical high frequency emphasizing means 24 _3, Slnog output from the delay unit 13, Slnog is 1H delayed by the first scanning conversion means 15, the first scanning conversion means 15 and the third switch 23 Second scanning conversion means 1
5, three Slnog signals further delayed by 1H, and Slnog further delayed from the second scan conversion means 15 through the 1H memory 25, that is, 4 signals adjacent in the vertical direction.
Slnog for the line is input together.

[0096] vertical high frequency emphasizing means 24 _2, the adder 3
5, Slnog output from the delay means 13 and 1H
While adding the output Slnog delayed by the memory 25, the second adder 36 adds the first scan conversion unit 15
And the second scan conversion means 16
And Slnog delayed and output. And
The subtracter 37 outputs the first adder 3 from the output of the second adder 36.
5 is subtracted, and the output of the subtracter 37 is attenuated to a half level by the attenuator 39, thereby extracting a vertical high-frequency emphasis component. And then output.

[0097] Then, signals of the vertical high-frequency emphasizing component extracted by the vertical high-frequency emphasizing means 24 _3, Slnog output from the delay unit 13, Slnog together which is 1H delayed by the first scanning conversion means 15, It is given to the signal adding means 17 _3.

[0098] The signal adding means 17 _3, sequential scanning CCD1
After adding Slnog of two adjacent lines in the vertical direction in units of pixels and further adding a vertical high-frequency emphasis component to this,
The signal is input to the camera signal processing unit 20 via the third switch 19, subjected to predetermined signal processing, and output as a non-interlaced scanning signal.

[0099] Thus, in the embodiment 3, the vertical high frequency emphasizing means 24 _3, since the vertical high-frequency emphasis to at least a vertical 4 lines Slnog progressive scan CCD 11, embodiment 2 It is possible to achieve a higher vertical resolution at the time of vertical high frequency enhancement than in the case, and it is possible to improve the image quality.

In the third embodiment, the case where two scan conversion means 15 and 16 and one H memory 25 are used has been described. However, a configuration using more than two scan conversion means may be used. It is.

[0101]

According to the present invention, the following effects can be obtained.

(1) According to the first aspect of the present invention, in the dynamic range expansion mode, the dynamic range expansion rate is lower than in the prior art, so that the S / N of the short-time exposure signal itself is good, and Sufficient gradation can be obtained. Therefore, an even better display image can be obtained as compared with the related art.

Further, a sequential scanning mode can be selected as required, and therefore, for example, an application such as printing out a high-quality image by non-interlace can be realized.

(2) According to the second aspect of the present invention, since it is also used as a delay element, it is not necessary to increase the number of delay elements, and cost can be reduced.

(3) According to the third aspect of the invention, in the progressive scanning mode, it is possible to realize vertical high resolution by vertical high frequency emphasis by the vertical high frequency emphasis means.

(4) According to the fourth aspect of the present invention, the vertical high-frequency emphasis means extracts the vertical high-frequency emphasis component from three lines in the vertical direction, so that the occurrence of horizontal stripes can be avoided and the resolution in the vertical direction can be increased. be able to.

(5) According to the fifth aspect of the invention, the vertical high frequency emphasis means extracts the vertical high frequency emphasis component from at least four lines in the vertical direction, so that the image quality is further improved as compared with the case of the fourth aspect. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a video camera according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between an exposure amount and an exposure time for obtaining Slnog and Sshort in a dynamic range expansion mode in the configuration of FIG. 1;

FIG. 3 is an explanatory diagram showing transfer timing of each signal of Slnog and Sshort in a dynamic range expansion mode in the configuration of FIG. 1;

FIG. 4 is a characteristic diagram showing a relationship among Slnog, Sshort, and Smix in the dynamic range expansion mode in the configuration of FIG.

FIG. 5 is a block diagram showing a configuration of a video camera according to Embodiment 2 of the present invention.

FIG. 6 is a block diagram showing a specific configuration of a vertical high-frequency emphasis unit of the video camera in FIG. 5;

FIG. 7 is a block diagram showing a configuration of a video camera according to Embodiment 3 of the present invention.

8 is a block diagram showing a specific configuration of a vertical high-frequency emphasis unit of the video camera in FIG. 7;

FIG. 9 is a block diagram showing a configuration of a conventional video camera.

FIG. 10 shows a conventional video camera, a progressive scan CC.
Schematic diagram showing the accumulation and transfer status of Slnog and Sshort obtained by photoelectric conversion in D

FIG. 11 is an explanatory diagram showing a relationship between an exposure amount and an exposure time for obtaining Slnog and Sshort in a dynamic range expansion mode in a conventional configuration.

12 is a characteristic diagram showing a relationship between Slnog, Sshort, and Smix in the dynamic range expansion mode in the configuration of FIG.

[Explanation of symbols]

10: imaging lens, 11: progressive scanning CCD, 12: first
, 13 ... delay means, 15 ... first scan conversion means, 16 ... second scan conversion means, 17 ₁ , 17 ₂ , 17 ₃
... Signal adding means, 18 ... Signal synthesizing means, 19 ... Second switch, 20 ... Camera signal processing unit, 23 ... Third switch, 24 ₂ , 24 ₃ ... Vertical high frequency emphasis means, 25 ... 1H memory.

Claims (5)

[Claims] 1. A progressive scanning CCD, and the progressive scanning CCD
And a camera signal processing unit for converting the output of the camera into a video signal suitable for image display. When the exposure amount is changed in accordance with the dynamic range expansion mode, the output is output from the progressive scanning CCD. A first switch for separating a long-time exposure signal and a short-time exposure signal; delay means for delaying the long-time exposure signal by the exposure time of the short-time exposure signal; First and second scan conversion means for performing scan conversion so that each one line is output for a time corresponding to one horizontal scanning period; and scan conversion performed by the first and second scan conversion means. A signal synthesizing means for synthesizing the output long-time exposure signal and short-time exposure signal to generate a synthesized signal; and a length of two vertically adjacent lines according to the sequential scanning mode. Signal addition means for adding the inter-exposure signals to each other on a pixel-by-pixel basis; an output of the signal combination means in the dynamic range expansion mode; And a second switch for providing a dynamic range expansion mode and a progressive scanning mode. 2. The video camera according to claim 1, wherein said first scan conversion means is also used as a delay element for delaying a long exposure signal by one horizontal scanning period in accordance with a progressive scan mode. A video camera characterized in that both long-time exposure signals before and after passing through a scan conversion unit are input to the signal addition unit. 3. A video camera according to claim 1, wherein a vertical high-frequency emphasis component is extracted based on a long-time exposure signal for at least three vertically adjacent lines in accordance with a progressive scanning mode. A video camera comprising vertical high frequency emphasis means. 4. The video camera according to claim 3, wherein said first and second scan conversion means are both used as delay elements for delaying a long-time exposure signal by one horizontal scanning period in accordance with a progressive scanning mode. And a long-time exposure signal before and after passing through the first and second scan conversion means, respectively, is input to the vertical high frequency emphasis means. 5. The video camera according to claim 4, wherein at least one 1H delay element for further delaying a long-time exposure signal by one horizontal scanning period is added to said first and second scan conversion means. A long exposure signal before and after passing through the 1H delay element is input to the vertical high frequency emphasis means.