JPH07322129A - Still picture image pickup device - Google Patents

Abstract

PURPOSE:To provide a still picture image pickup device which can fetch a subject that is free from any color slippage or residual image and then can store the subject or display it as image via a monitor. CONSTITUTION:The image of a subject that is formed by a lens 50 is stored in a 1st storage circuit 54 by a solid state image pickup element 51, an A/D converter 52 and a digital signal processing circuit 53. Meanwhile a 2nd storage circuit 55 stores the digital signals equivalent to a single frame which are read out of the circuit 54. A movement detector means 56 inputs the digital signals which are read out of both circuits 54 and 55 and decides whether both signals have the same value for each pixel. Then the means 56 outputs a control signal to show whether the subject is moving or not based on the result of the preceding decision. A control circuit 57 permits or inhibits the writing of the digital signals to the circuit 55 according to the control signal that is received from the means 56.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still image pickup device for capturing a color subject image for use in a presentation system or the like.

[0002]

2. Description of the Related Art Various presentation systems have been developed which store a color subject image and present a still image to a large number of listeners on a monitor screen. FIG.
FIG. 1 is a block diagram disclosed in Japanese Patent Application Laid-Open No. 2-200086 and showing an example of a color imaging device used in this type of system.

In the figure, 1 is a shutter, 2 is a lens or lens group, 3 is a transmitted light wavelength selecting means, 4 is an image pickup element, 5 is a buffer amplifier, 6 is an A / D converter, 7 is a signal processing device, Reference numeral 8 is a storage device, 9 is a mechanical system drive device, 10 is a timing control device, and 11 is an external trigger terminal. Here, the transmitted light wavelength selection means 3 is for selecting wavelengths corresponding to at least three different colors of light, and for example, R (red), G (green), B (blue), or Cy. (Cyan), Ye (yellow), G (green), W (white) color filters.

FIG. 17 shows the transmitted light wavelength selection means 3 of FIG.
The specific configuration of is shown in relation to the lens 2 and the image pickup device 4. In the figure, a light ray from a subject that has entered the lens or the lens group 2 is formed as a subject image on the surface of the image pickup device 4 arranged behind the focal point 23. The color filter 24 is arranged between the lens or the lens group 2 and the image sensor 4. This color filter 24 includes, for example, three different filter elements 20,
21 and 22. The filter element 20 transmits R light, the filter element 21 transmits G light, and the filter element 22 transmits B light. The figure shows a state in which only light that has passed through the filter element 21 of the color filter, that is, light having a green spectral component, reaches the surface of the image sensor 4. The color filter 24 includes each filter element 2
It is configured to be slidable in a direction indicated by an arrow 25 in the drawing by a predetermined pitch corresponding to the pitch at which 0, 21, and 22 are arranged.

FIG. 18 is a diagram showing the structure of the color filter 24. This figure is viewed from the incident surface of the light ray, and each filter element 20, 21, 22 is formed so that only light having each spectral component of R, G, B is transmitted. P is three filter elements 20, 2 arranged in the sliding direction 25 of the color filter 24.
The pitch is 1, 22.

FIG. 19 is a diagram showing the structure of another color filter 32. This figure is viewed from the light incident surface, and each filter element 26, 27, 28 is formed so that only the light having the respective spectral components of R, G, B is transmitted. This color filter 32 has points 29
Is controlled so as to rotate in a counterclockwise direction indicated by an arrow 30 by a predetermined angle (here, 120 degrees). For example, in a state where only light having a spectral component G is transmitted, It is superimposed on the image pickup surface of the image pickup device at a position indicated by a frame 31.

Next, the operation of this color image pickup apparatus will be described. FIG. 20 shows the operation timing of each part, and 41 is the timing of the trigger signal applied to the external trigger terminal 11. When the trigger signal is applied, the timing control device 10 calculates the shutter speed based on the light amount of the subject, the sensitivity of the image sensor, the image capturing condition set from the outside, and the like. 42 in the figure shows a signal for controlling the time when the shutter 1 is opened. This signal 42 is transmitted to the mechanical system driving device 9, and the mechanical system driving device 9 controls the opening / closing of the shutter 1 so as to open the shutter only for the period shown by Ts in the drawing.

Here, the color filters 24 and 32 are slid in the direction of arrow 25 in FIG.
In FIG. 9, the image is rotated in the direction of arrow 30, but the periods in which the color filters corresponding to R, G, and B operate at this time are Tr, Tg, and Tb in FIG. That is, the timing control device 10 divides the period Ts in which the shutter 1 is opened into three, Tr, Tg, and Tb, and transmits the control signals 43, 44, and 45 including the information to the mechanical system drive device 9. The mechanical system driving device 9 controls the transmitted light wavelength selection means 3 based on the control signals 43, 44 and 45, and the light having the spectral component of R in the period Tr, the period Tg.
Light having a G spectral component and light having a B spectral component in the period Tb are transmitted. The image pickup device 4 receives the light having the above-mentioned R, G, and B spectral components,
These are sequentially converted into electric signals, and the electric signals are transmitted to the signal processing device 7 via the buffer amplifier 5 and the A / D converter 6. The signal processing device 7 receives the electric signals corresponding to the respective lights having the R, G, and B spectral components, performs a predetermined process to combine the electric signals, and then generates a color image signal. The storage device 8 stores the color image signal.

[0009]

Since the conventional still image pickup device is constructed as described above, it has the following problems. First, it takes a lot of time to generate one still screen because the color filters are configured to sequentially capture the three color lights of R, G and B by sliding or rotating the color filters. Therefore, the positional relationship between the subject and the image pickup device must be fixed at least during the period Ts during which the shutter 1 is open, and when the subject image moves in the middle, color shift or the like occurs, resulting in a clear image. Cannot capture images.

Second, in the case of giving a presentation while showing the subject on a monitor screen or the like in front of an actual listener, the subject may be moved for the same reason,
An afterimage occurs when changing the image, resulting in an unsightly screen.

The present invention has been made in order to solve the above problems, and a first object thereof is to provide a still image pickup apparatus which can capture a clear subject image without color shift. .

A second object of the present invention is to provide a still image pickup apparatus capable of displaying a subject image having no afterimage as an image through a monitor even when the subject is changed or moved.

[0013]

In a still image pickup device according to a first aspect of the present invention, a lens, a solid-state image pickup device for converting a subject image formed by the lens into an electric signal, and a solid-state image pickup device are provided. In a still image pickup device comprising an A / D converter for converting a signal into a digital signal and a digital signal processing circuit for processing the digital signal converted by the A / D converter, A first memory circuit that stores a signal, a second memory circuit that stores a signal read from the first memory circuit, a digital signal that is sequentially read from the first memory circuit, and the second memory circuit. A digital signal sequentially read from the memory circuit is input to detect the motion of the subject, and the first and second motion detection means respond to a control signal from the motion detection means. Control means for controlling to permit or prohibit the writing of the digital signal to the memory circuit, and a first D / A converter for converting the digital signal read from the first memory circuit into an analog signal. And a second D / A converter for converting a digital signal read from the second memory circuit into an analog signal.

According to the still image pickup device of claim 2,
In the above, the first and second D / A converters include
A video display means for displaying a still image from an analog signal is connected to each of them.

According to the still image pickup device of claim 3,
Or 2, the motion detecting means subtracts a digital signal read from the second storage circuit from a digital signal read from the first storage circuit, and a difference value from the subtraction circuit. A comparing circuit for comparing with a preset reference value, a recognizing unit for recognizing a change in a pattern of a control signal output according to the result of comparison by the comparing circuit, and a period for making a judgment by the recognizing unit are set. And a determination period setting means.

According to the still image pickup device of claim 4,
Or 2, the motion detecting means subtracts the digital signal read from the first storage circuit from the digital signal read from the second storage circuit, and outputs an absolute value of the result. An adder circuit for sequentially adding the outputs from the arithmetic circuit; a third memory circuit for storing the added value added by the adder circuit and outputting the sum of the added values every set number of times; A comparison circuit that compares the total addition value sequentially read from the third storage circuit with a preset reference value; and a recognition unit that recognizes a change in the pattern of the control signal from the comparison circuit. To do.

According to the still image pickup device of claim 5,
The motion detection means further includes a determination period setting means for setting a period to be determined by the recognition means.

[0018]

According to another aspect of the present invention, the still image pickup device detects whether or not the object is moving by the motion detecting means, sends a control signal according to the detection result to the control circuit, and controls according to the control signal. The circuit controls to allow or prohibit writing of the digital signal to the second memory circuit.

A still image pickup device according to a second aspect of the present invention comprises:
By projecting the still image from the analog signal of the second D / A converter on each, it is connected to the second D / A converter while watching the still image from the first D / A converter. By determining the composition of the subject image in the video display means, it is possible to present a clear still image with no color shift or afterimage to the viewer.

According to another aspect of the still image pickup device of the present invention, the digital signal read from the first storage circuit and the digital signal read from the second storage circuit are subtracted, and the difference value is set as a preset reference value. Compare. When the recognition unit recognizes the change in the pattern of the output signal according to the comparison result, the determination period setting unit sets the determination period and outputs the control signal. In response to the control signal, the control circuit performs control for allowing or prohibiting writing of the digital signal to the second memory circuit.

According to another aspect of the still image pickup device of the present invention, the digital signal read from the first memory circuit and the digital signal read from the second memory circuit are subtracted, and the absolute value of the result is sequentially added in the adder circuit. Then, the sum of the added values is output every number of times set in the third memory circuit. Compare this total added value with the preset reference value,
The recognition means recognizes the change in the pattern of the output signal according to the comparison result and outputs the control signal. In response to the control signal, the control circuit performs control for allowing or prohibiting writing of the digital signal to the second memory circuit.

In the still image pickup device according to the fifth aspect, the determination period setting means sets the period for which the recognition means determines the period.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Example 1

FIG. 1 is a block diagram showing an example of a still image pickup device of the present invention. Reference numeral 50 is a lens, 51 is a solid-state image sensor for converting an object image formed by the lens 50 into an electric signal, 52 is an A / D converter for converting an electric signal from the solid-state image sensor 51 into a digital signal, and 53 is A. / D
A digital signal processing circuit for processing the digital signal converted by the converter 52.

Reference numeral 54 is a first storage circuit for storing the subject image signal-processed by the digital signal processing circuit 53 on a frame-by-frame basis. The digital signal on a frame-by-frame basis is stored in the second storage circuit 55, the motion detecting means 56 and First D / A
It is connected so as to be sent to the converter 58. The second memory circuit 55 reads 1 from the first memory circuit 54.
The digital signal read out from the first memory circuit 54 and the digital signal read out from the second memory circuit 55 are input to the motion detecting means 56 in the motion detecting means 56, and both are stored pixel by pixel. Whether or not the values are the same is determined, and a control signal indicating whether or not the subject is moving is output according to the result. Control circuit 57
Is for controlling to permit or prohibit the writing of the digital signal to the second memory circuit 55 in accordance with the control signal from the motion detecting means 56. The digital signal read from the first memory circuit 54 is the first
The digital signal which is converted into an analog signal by the D / A converter 58 and is read from the second memory circuit 55 is
It is converted into an analog signal by the second D / A converter 59 and is displayed on a video display device such as a monitor (not shown).

FIG. 2 is a diagram showing an example of two objects having different shapes. The same figure (a) shows the case where a square object 61 is placed on the black subject table 60, and the same figure (b) shows the case where a round object 62 is placed on the black subject table 60 similarly. .

Next, the operation of the still image pickup device when a digital signal is sent to the second memory circuit 55 and the motion detecting means 56 will be described. Now, when the rectangular object 61 shown in FIG. 2A is photographed from above, the subject image captured by the still image capturing device is stored in the first storage circuit 54 in frame units.

FIG. 3 shows a partial area of the subject image stored as a digital signal in the second storage circuit 55. In FIG. 3, A1, A2 and A3 are addresses in the vertical direction, B1 to B7 are addresses in the horizontal direction, and the numerical value in each area is the value of the digital signal corresponding to the density of the image. The digital signal stored in the second storage circuit 55 is sequentially moved at the same timing as the digital signal of the next frame stored in the first storage circuit 54, and the motion detection circuit 5
6 is read. In the motion detection circuit 56, a calculation is performed for each corresponding address between the digital signal sent from the second storage circuit 55 and the digital signal of the next frame output from the first storage circuit 54. For example, subtraction is performed. Then, the calculation results for all the addresses are compared frame by frame, and it is determined whether or not the pattern of the comparison result changes in a preset determination period.

For example, if a still image pickup device is used,
It is assumed that a period for capturing frames is set as this determination period. First and second memory circuit 5
If the pattern of the calculation and comparison results for the digital signals for each address read from Nos.
A control signal having a positive logical value (hereinafter, referred to as H) is always output from 6. On the contrary, when the pattern of the comparison result by the motion detecting means 56 changes even by one address during the determination period of 4 frames, the motion detecting means 56 controls a negative logical value (hereinafter, referred to as L). The signal is always output. Thus, if the control signal for the set determination period is H, it is determined that the subject image captured by the still image capturing apparatus is stationary, and conversely, if the control signal is L, the subject image is determined. It is determined that it is changing, that is, the object is moving or the camera itself is moving to change the subject.

This control signal is sent from the motion detecting means 56 to the control circuit 57. When the H control signal is input, the control circuit 57 enables the writing of the digital signal to the second memory circuit 55. When the writing is enabled, the subject images are sequentially stored in the second storage circuit 55 as digital signals, and are output as image data from the storage circuit 55 to the second D / A converter 59. . As a result, the digital signal input to the second D / A converter 59 is converted into an analog signal and displayed on a video display device such as a monitor.

Incidentally, the first and second D / A converters 58, 5
It is assumed that each of the video display devices 9 is connected to another video display device, and a presentation is performed by the video display device connected to the second D / A converter 59.
In that case, the image from the first D / A converter 58 is used for checking the subject image. However, as will be described later, when the subject image is simply captured in the still image pickup device, the same monitor can be connected to the two D / A converters 58 and 59 and used.

Next, the case where the camera is moved from the square object 61 of FIG. 2A or the object itself is moved in order to make the round object 62 shown in FIG. 2B an object will be described.

Similar to FIG. 3, FIG. 4 shows the first storage circuit 5
4 is a partial region of the subject image stored as a digital signal. In FIG. 4, the state of the digital signal in the state where the object image of the rectangular object 61 starts to move is shown. In the second storage circuit 55, the subject image captured by the still image pickup device before the start of movement of the subject image is stored in a state as shown in FIG.
As a result, the digital signal stored in the state of FIG. 4 is input to the motion detecting means 56 from the first storage circuit 54, and at the same time, the digital signal stored in the state of FIG. 3 is output from the second storage circuit 55. , Will be input for each corresponding address.

The motion detecting means 56 calculates and compares these digital signals and outputs a control signal according to the motion of the subject image. As can be seen by comparing FIGS. 3 and 4, addresses (A2, B3), (A2, B
4), (A2, B5), (A2, B6), (A2, B
The values of the digital signals 7) and (A3, B3) are different, and the subject image of the square object 61 continues to move thereafter. Therefore, the pattern of the comparison result in the motion detecting means 56 is set in the set four frames. It changes throughout the judgment period. Therefore, the motion detection means 56 outputs an L control signal. As a result, as long as the subject image is moving, the movement of the square object 61 is detected from the subject image captured by the still image capturing device and stored in the first storage circuit 54. Then, when this control signal L is sent to the control circuit 57, the control circuit 57 prohibits the writing of the digital signal from the first memory circuit 54 to the second memory circuit 55.

In this way, the still image before the movement of the rectangular object 61 is continuously displayed on the video display device such as a monitor which displays the output from the second D / A converter 59. On the other hand, on the video display device connected to the first D / A converter 58, the moving subject images shown in FIG. 4 are projected one after another. The image in this case has color shifts and afterimages.

Next, the operation when the subject image stored in the first storage circuit 54 is stationary, that is, when the image of the round object 62 is taken in by the still image pickup device will be described.

Similar to FIG. 4, FIG. 5 shows the first storage circuit 5
4 is a partial region of the subject image stored as a digital signal. In FIG. 5, the image in which the subject image of the round object 62 is changed is stored as a digital signal. In the second memory circuit 55, since the writing of the digital signal is prohibited, the digital signal still shown in FIG.
It is stored as a subject image captured by the still image pickup device before the movement of the subject image is started. Therefore, the digital signal stored in the state shown in FIG. 5 is input to the motion detecting means 56 from the first storage circuit 54, and simultaneously stored from the second storage circuit 55 in the state shown in FIG. 3 for each corresponding address. The digital signal thus input is input.

The motion detecting means 56 calculates and compares these digital signals, compares the calculation results for all addresses on a frame-by-frame basis, and judges the four frames in which the pattern of the comparison result is preset. It is determined whether or not the time period changes. In this case, since the subject image of the round object 62 stored in the first storage circuit 54 is the digital signal of the already changed image, it does not change any more. Therefore, even if the values of the digital signals of the corresponding addresses are different between FIGS. 3 and 5, the pattern of the comparison result in the motion detecting means 56 does not change during the determination period of the next four frames. Therefore, the movement detecting means 56 determines that the subject is not moving, and outputs the H control signal. When the control signal H is sent to the control circuit 57, the control circuit 57 puts the digital signal from the first memory circuit 54 into the second memory circuit 55 in an enabled state, so that it is shown in FIG. Digital signals are sequentially written and stored. Then, the digital signal input to the second D / A converter 59 is converted into an analog signal, and the image of the round object 62 is displayed on a video display device such as a monitor.

In this way, the first D / A converter 58
An image is always displayed on a video display device such as a monitor that displays the output of irrespective of whether the subject is moving or not. Then, only the image of the changed subject is displayed as a still image on the image display device such as a monitor that displays the output of the second D / A converter 59. Therefore, when this still image capturing device is used for a presentation, composition can be determined on one screen and only the changed subject image can be displayed on the other screen without causing afterimages.

Embodiment 2 In this Embodiment 2, a still image pickup device is constituted by the motion detecting means having a structure different from that of the Embodiment 1 shown in FIG. FIG. 6 is a block diagram of what corresponds to the motion detecting means 56 of FIG.

In the figure, 63 is a subtracting circuit, which subtracts the digital signal from the first memory circuit 54 and the digital signal from the second memory circuit 55 for each corresponding address. Reference numeral 64 is a comparison circuit for comparing the subtraction result of the subtraction circuit 63 with a set reference value. The comparison result of the comparison circuit 64 is output to the recognizing means 65, and the recognizing means 65 is connected to the determination period setting means 66.
When a signal corresponding to the pattern of the comparison result in the comparison circuit 64 is input, the recognizing means 65 recognizes whether or not the pattern changes in units of frames within the determination period set by the determination period setting means 66, and this It is configured to output a predetermined control signal to the control circuit 57 according to the recognition result.

Next, a motion detecting operation in the still image pickup apparatus having the above-mentioned structure will be described. First, it is assumed that the still image capturing apparatus has the rectangular object 61 shown in FIG. In that case, the first storage circuit 5
In FIG. 4, a digital signal corresponding to a square subject image is stored, and at the next time point, the same digital signal is sent from the first storage circuit 54 to the second storage circuit 55. In the state shown in FIG. Remembered.

Now, it is assumed that the square object 61 is placed in a stationary state, and digital signals in the state shown in FIG. 7B are successively input to the first storage circuit 54.
Digital signals read from the two storage circuits 54 and 55 are input to the subtraction circuit 63 at the same timing for each corresponding address. For example, the horizontal address (A
1, B1), (A1, B2), ... The values of the digital signals are sequentially subtracted. The subtracted difference value is output to the comparison circuit 64. The comparison circuit 64 compares with a preset reference value, and outputs a signal of positive logic value H when the difference value is the same value as the reference value, and a signal of negative logic value L when the difference value is different. , Are output as comparison results.

The comparison results are sent to the recognizing means 65 one after another, and the recognizing means 65 determines whether or not the pattern of these comparison results changes in frame units within the judgment period set in the judgment period setting means 66. Is recognized. If there is no change in the pattern of the series of comparison results, the H control signal is output to the control circuit 57. However, when it is recognized that the comparison result pattern is different from the preceding frame even with one address, the recognition circuit 65 causes the control circuit 5 to recognize the difference.
A control signal of L is output to 7.

In the control circuit 57, as in the case of the first embodiment, when the H control signal is input, the writing of the digital signal to the second memory circuit 55 is enabled,
If the control signal is L, the writing of the digital signal from the first memory circuit 54 to the second memory circuit 55 is prohibited.

FIG. 8 shows an example of the operation of the motion detecting means in the above case. 7A and 7B are diagrams showing the storage state of digital signals in the storage circuits 54 and 55, FIG. 6C is a diagram showing the difference value subtracted by the subtraction circuit 63, and FIG. FIG. 6 is a diagram showing a part of a comparison result pattern of the comparison circuit 64.

Now, 0 is set as the reference value and 4 frames are set as the judgment period. As a result of the subtraction in the subtraction circuit 63, if all the difference values become 0 as shown in FIG. 6C, the reference value and the difference values match, and therefore the comparison circuit 64 always outputs the comparison result of H. It Therefore, the recognizing means 65 determines whether or not there is a change in the pattern of the comparison result among the set four frames. In FIG. 6D, only a part of the pattern of one frame is shown, but if the pattern of the comparison result does not change in the determination period of four frames or more, the recognition means 65 causes the control circuit 57 to change. H control signal is output to the second
The writing of the digital signal into the memory circuit 55 is enabled.

Next, a motion detecting operation when the square object 61 is moved and the round object 62 is captured as a subject image in the still image pickup device will be described. Similar to the case of FIG.
9A to 9D, the states of the digital signals of the first storage circuit 54 and the second storage circuit 55 immediately after the rectangular object 61 starts moving, and the difference value output from the subtraction circuit 63. , And a part of the pattern of the comparison result.

The value "255" of the digital signal stored in the first storage circuit 54 indicates that the subject image is moving in the lower right direction in the figure, where the subject image is
It is assumed that the square object 61 further moves to the lower right as the object 61 moves. On the other hand, in the second memory circuit 55, once the write prohibition state is set by the control circuit 57, the digital signal stored therein is in a stationary state regardless of the actual movement of the rectangular object 61. The image of the subject remains. Therefore, immediately after the rectangular object 61 starts to move, all the difference values of the subtraction circuit 63 do not become 0, and “25” is set in the address portion corresponding to the shifted area of the subject image.
5 ”((c) in the figure). Therefore, the output of the comparison circuit has a pattern including the negative logical value L in the corresponding portion.

FIGS. 10A to 10D show how the pattern of the comparison result output from the comparison circuit 64 to the recognition means 65 changes with the movement of the subject. The recognizing means 65 compares the comparison result patterns frame by frame over the set four frames, and when it is recognized that the comparison result patterns are different from the preceding frames even by one address, the control circuit 57 is notified. To L
Control signal is output. Therefore, when the pattern of the comparison result changes as shown in FIG. 10, it is determined that the subject image is moving, and the control signal L sets the second storage circuit 55 to the write-inhibited state.

Next, when the square object 61 forming the subject image up to that time is removed and the round object 62 is taken into the still image pickup device as a still subject image,
The motion detection operation will be described. As in the case of FIG. 9, FIG.
In (a) to (d), the round object 6 in the first memory circuit 54 is
2 shows a state in which a digital signal of 2 is stored, a state in which a digital signal of the rectangular object 61 is stored in the second storage circuit 55, a difference value output from the subtraction circuit 63, and a part of a comparison result pattern. ing.

The digital signal of the first memory circuit 54 shown in FIG. 11A corresponds to the round object 62, and the second memory circuit 5 in the write-protected state.
In FIG. 5, as shown in FIG. 11B, a digital signal immediately before the rectangular object 61 starts moving is stored.
The digital signals of the storage circuits 54 and 55 are sent to the subtraction circuit 63 for each corresponding address, and the difference value is calculated. The difference value shown in FIG. 11C is output from the subtraction circuit 63 to the comparison circuit 64 and compared with the reference value 0 set therein. The comparison circuit 64 shows the comparison result in FIG.
The signal pattern of L or H shown in 1 (d) is successively supplied to the recognition means 65.

Here, the subject photographed by the still image pickup device is the round object 62 that has already stopped. Then, assuming that the subject image captured in the first storage circuit 54 does not move for a determination period of at least 4 frames or more, the digital images input to the subtraction circuit 63 from the first and second storage circuits 54 and 55, respectively. There is no change in the signal. Therefore, the recognizing means 6 via the comparison circuit 64.
Since the signal pattern supplied to No. 5 does not change from the state shown in FIG. 11D, the recognition unit 65 determines that the subject is not moving and outputs the H control signal. When this control signal H is sent to the control circuit 57, the control circuit 57 enables the writing of the digital signal from the first memory circuit 54 to the second memory circuit 55. Thus, FIG.
The digital signal shown in (a) is sequentially written in the second storage circuit 55, converted into an analog signal by the second D / A converter 59, and an image of the round object 62 is displayed on a video display device such as a monitor. It will be reflected in.

By setting the reference value of the comparison circuit 64 to a certain level, the first storage circuit 5
Even if the subject image captured in 4 moves a little or changes due to adjustment of the light rays, it can be determined as an error range.
That is, even if the digital signal input from the subtraction circuit 63 to the comparison circuit 64 changes slightly, it is processed as noise in pixel units so that the signal pattern supplied to the recognition means 65 is not changed. In this way, the recognizing means 65 correctly determines that the subject is not moving, and can output the H control signal to the control circuit 57.

As described above, an image is always displayed on the image display device such as a monitor that displays the output of the first D / A converter 58 regardless of whether or not the subject is moving. Then, only the image of the changed subject is displayed as a still image on the image display device such as a monitor that displays the output of the second D / A converter 59. Therefore, when this still image pickup device is used for a presentation or the like, the composition can be determined on one screen and only the changed subject image can be displayed on the other screen without causing an afterimage. Further, in the comparison of the difference values, the movement of the subject image is detected pixel by pixel using a reference value that can be set arbitrarily. Therefore, noise generated in the pattern of the comparison result is removed, and the still image capturing apparatus is removed. It is possible to more accurately determine the movement of the subject image captured by the.

Third Embodiment In the third embodiment, a still image pickup device is constituted by the motion detecting means having a structure different from that of the second embodiment shown in FIG. FIG. 12 shows the motion detecting means 56 of FIG. 1, a control circuit 57 connected to the motion detecting means 56, and first and second memory circuits 54 and 5.
5 is a block diagram showing a configuration of a portion corresponding to No. 5.

In the figure, 67 is an arithmetic circuit for subtracting the digital signals read from the first memory circuit 54 and the second memory circuit 55 for each corresponding address and outputting the absolute value thereof. 68 is an adder circuit for sequentially adding the values sent from the arithmetic circuit 67, and 69 is an adder circuit 68.
The third storage circuit 70 stores the added value added in step (1) and outputs the sum of the added values every set number of times, and 70 is a comparison circuit that compares the added total value with a preset reference value.

The comparison result of the comparison circuit 70 is the recognition means 71.
Is output to the comparison circuit 7 in the recognition means 71.
When a signal corresponding to the pattern of the comparison result at 0 is input,
It is recognized whether or not the pattern changes frame by frame within the set determination period. Then, a predetermined control signal H or L is output from the recognition means 71 to the control circuit 57 according to the recognition result.

Next, the operation of motion detection in the still image pickup apparatus having the above-mentioned structure will be described. FIG. 13 shows an example of the motion detection operation when the subject image is stationary. FIGS. 9A and 9B show the storage circuit 54,
55 is a diagram showing the storage state of the digital signal at 55, and FIG. 17C is a diagram showing the absolute value of the difference subtracted by the arithmetic circuit 67.

Now, as the reference value in the comparison circuit 70, "1" is set.
200 "is set, and four frames are set as the determination period in the recognition unit 71. As a result of the subtraction in the arithmetic circuit 67, if all the difference values become 0 as shown in FIG. 7C, the output 0 is sent to the adder circuit 68 and sequentially added. The addition result is temporarily stored in the third storage circuit 69, and is then stored in the third storage circuit 69.
The value stored in the storage circuit 69 is read out and added again. In the third memory circuit 69, the added total value of the set number of times is sequentially output to the comparison circuit 70.

The number of times of addition in the adder circuit 68 is set by
It can be set to an arbitrary number in advance, and for example, it is assumed that the total value obtained by adding seven times is output from the third storage circuit 69. As an example of a digital value that is added seven times, as shown in FIG.
Assuming that the addition total value is output as indicated by a region surrounded by a dotted line in 3 (c), 0 is output to the comparison circuit 70. The comparison circuit 70 outputs a comparison result of H if the added total value is higher than the reference value, and outputs a comparison result of L if they match or are low. As long as the subject image captured by the still image capturing apparatus is stationary, the addition result output from the third storage circuit 69 is low with respect to the reference value 1200, so the comparison circuit 70 always outputs L. The comparison result of is output. Therefore, the recognition unit 71 determines that the pattern of the comparison result does not change during the set four frames. In this way, the control signal H is output from the recognition means 71 to the control circuit 57, and the second storage circuit 55 is output.
Enables writing of digital signals to.

Next, a square object 61 to a round object 62
A motion detection operation when a still image capturing device captures a subject image that changes to 1 will be described. 14 (a) to (c)
9A to 9C correspond to the states of the digital signals of the first storage circuit 54 and the second storage circuit 55 immediately after the rectangular object 61 starts moving, and the subtraction circuit 63. Each of them shows a part of the absolute value of the difference output from.

The value "255" of the digital signal stored in the first storage circuit 54 indicates that the subject image is moving in the lower right direction in the figure, where the subject image is
It is assumed that the square object 61 further moves to the lower right as the object 61 moves. On the other hand, in the second memory circuit 55, once the write prohibition state is set by the control circuit 57, the digital signal stored therein is in a stationary state regardless of the actual movement of the rectangular object 61. The image of the subject remains. Therefore, immediately after the rectangular object 61 starts moving, the absolute values of the differences of the arithmetic circuit 67 do not all become 0, but become "255" in the address portion corresponding to the shifted area of the subject image (the same). Figure (c)).

The calculation result by the calculation circuit 67 is the third result.
Are sequentially added by the storage circuit 69 and the addition circuit 68, and the total value of seven additions is read out to the comparison circuit 70. Now, as an example of the digital value added seven times, as shown in FIG.
Total value "15" indicated by the area surrounded by the dotted line
If "30" is output to the comparison circuit 70, it is compared with the reference value "1200". In the comparison circuit 70,
If the added total value is higher than the reference value, H is output, and if it is lower or lower, the L comparison result is output. Therefore, if the subject image captured by the still image capturing apparatus continues to move,
A change in the addition total value will always occur, and the pattern of the comparison result will also change. The recognizing means 71 outputs a control signal L to the control circuit 57 in response to a change in the pattern of the comparison result during the set four frames, whereby the second storage circuit 55 is set to the write-protected state.

Next, the motion detecting operation when the square object 61 forming the subject image up to that time is removed and the round object 62 is taken in as a still image by the still image pickup device will be described. As in the case of FIG. 14, FIG.
(C) shows a state in which the digital signal of the round object 62 is stored in the first storage circuit 54, a state in which the digital signal of the square object 61 is stored in the second storage circuit 55, and the output from the arithmetic circuit 67. Some of the difference values are shown.

The digital signal of the first memory circuit 54 shown in FIG. 15A corresponds to the round object 62, and the second memory circuit 5 in the write-protected state.
In FIG. 5, as shown in FIG. 15B, a digital signal immediately before the rectangular object 61 starts moving is stored.
The digital signals of the storage circuits 54 and 55 are sent to the arithmetic circuit 67 for each corresponding address, and the absolute value of the difference is calculated. When the calculation result is as shown in FIG. 15C, the addition result sequentially added by the addition circuit 68 is stored in the third storage circuit 69.

As an example of the digital value added seven times, if the addition total value "255" shown by the area surrounded by the dotted line in FIG. 15C is output to the comparison circuit 70, Is compared with the reference value “1200”. The comparison circuit 70 outputs a comparison result of H when the added total value is higher than the reference value, and outputs a comparison result of L when the addition value is equal to or lower than the reference value. After the lapse of the four-frame determination period, the magnitudes of the digital signals input from the first and second memory circuits 54 and 55 to the arithmetic circuit 63 remain unchanged. Therefore, the signal pattern supplied to the recognition unit 71 via the comparison circuit 70 does not change, and the recognition unit 71 determines that the subject is not moving and outputs the H control signal. This control signal H is applied to the control circuit 5
7, the control circuit 57 enables the writing of the digital signal from the first memory circuit 54 to the second memory circuit 55. Thus, the digital signals shown in FIG. 15A are sequentially written in the second storage circuit 55, converted into analog signals by the second D / A converter 59, and the image of the round object 62 is displayed on a monitor or the like. It will be displayed on the video display device.

The reference value of the comparison circuit 70 may be set according to the number of additions set in the addition circuit 68, that is, the number of pixels to be added, and the reference value is stored in the first storage circuit 54. The error range of the digital value of the subject image is determined to some extent. Further, by determining from which pixel position the digital signal input from the arithmetic circuit 67 to the comparison circuit 70 is taken out and added, the judgment area for the movement of the subject image taken into the still image pickup device can be determined.

Therefore, if the reference value and the number of times of addition are set according to the object to be presented and the shooting conditions, the object moves in the recognition means 65 even when the outline of the object image is not clear. Whether or not there is a correct control signal can be output to the control circuit 57.

When the subject image is simply taken in by the still image pickup device, the two D / A converters 58 and 59 are used.
Only one monitor is required to be connected to, and by shortening the determination period set by the recognition means 71, the time for capturing a still screen after the subject image has stopped moving can be shortened.

As described above, an image is always displayed on the image display device such as a monitor that displays the output of the first D / A converter 58 regardless of whether or not the subject is moving. Then, only the image of the changed subject is displayed as a still image on the image display device such as a monitor that displays the output of the second D / A converter 59. Therefore, when this still image pickup device is used for a presentation or the like, the composition can be determined on one screen and only the changed subject image can be displayed on the other screen without causing an afterimage.

Further, by using an arbitrarily set number of times of addition and a corresponding reference value, it is possible to detect the movement of the subject image in units of an arbitrary area taken in as the subject image. As a result, the motion of the subject image captured therein can be more accurately determined according to the shooting conditions of the still image capturing device.

[0073]

Since the present invention is constructed as described above, it has the following effects.

According to the invention of the still image pickup device described in claim 1, when the subject is moving, writing of the digital signal to the second memory circuit is prohibited, and writing is performed only when the subject image is stationary. Since it is configured to permit the above, it is possible to prevent the color shift or the afterimage of the object from being displayed on the screen when the subject is changed or moved in the presentation.

According to the still image pickup device of claim 2,
While watching the still image from the first D / A converter,
By determining the composition of the subject image on the image display means connected to the / A converter, a clear still image without color shift or afterimage can be presented to the viewer.

According to the still image pickup device of claim 3,
Since the reference value to be compared with the difference value is appropriately set to determine whether or not the subject is still on a pixel-by-pixel basis, noise generated in the pattern of the comparison result is removed, and the still image capturing apparatus is removed. The movement of the subject image taken in can be determined more accurately, and the control for permitting or prohibiting the writing of the digital signal to the second memory circuit can be surely performed.

According to the still image pickup device of claim 4,
Since it is determined whether or not the subject is still in a predetermined area unit, it is possible to more accurately determine the movement of the subject image captured therein according to the shooting conditions of the still image capturing device. The control for enabling or prohibiting the writing of the digital signal to the second memory circuit can be surely performed.

According to the still image pickup device of claim 5,
Since the determination period is set by the determination period setting unit, the determination period can be shortened to shorten the time for capturing and storing a still subject image.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a still image capturing device according to a first embodiment.

FIG. 2 is a perspective view showing two differently shaped subjects.

FIG. 3 is a state diagram showing a partial region of a subject image stored in a second storage circuit.

FIG. 4 is a state diagram showing a partial region of a subject image stored in a first storage circuit.

5 is a state diagram showing a partial region of a subject image of an object, which is stored in a first storage circuit and is different from that shown in FIG. 4. FIG.

FIG. 6 is a block diagram illustrating a detailed configuration of a motion detecting unit in the still image capturing apparatus according to the second embodiment.

FIG. 7 is a state diagram showing a second storage circuit and a partial region of a subject image stored in the first storage circuit.

8A and 8B show an example of the operation of the motion detecting means, FIGS. 8A and 8B are diagrams showing the storage states in the first and second storage circuits, and FIG. 8C is a subtraction circuit. FIG. 3D is a diagram showing a difference value subtracted by, and FIG. 3D is a diagram showing a part of a comparison result pattern of the comparison circuit.

FIG. 9 is an explanatory diagram showing an example of the operation of the motion detection means when capturing a changing subject image in a still image capturing device.

FIG. 10 is an explanatory diagram showing a pattern of comparison results that changes depending on the movement of a subject.

FIG. 11 is an explanatory diagram showing an example of the operation of the motion detection means when a still image of a subject is captured by a still image capturing device.

FIG. 12 is a block diagram showing a detailed configuration of a still image capturing apparatus according to a third embodiment of the present invention, first and second memory circuits, a control circuit, and motion detection means connected to them.

FIG. 13 shows an example of the operation of the motion detecting means,
7A and 7B are diagrams showing storage states in the first and second storage circuits, and FIG. 6C is a diagram showing difference values subtracted by the arithmetic circuit.

FIG. 14 is an explanatory diagram illustrating an example of the operation of the motion detection unit when capturing a changing subject image in a still image capturing device.

FIG. 15 is an explanatory diagram showing an example of the operation of the motion detecting means when capturing a still image of a subject in a still image capturing device.

FIG. 16 is a block diagram showing an example of a conventional color imaging device.

FIG. 17 is a configuration diagram showing the transmitted light wavelength selection means in FIG. 16, showing the relationship between the lens 2 and the image pickup device 4.

FIG. 18 is a diagram showing the structure of a color filter used as the transmitted light wavelength selection means of FIG. 16;

FIG. 19 is a diagram showing another structure of the color filter used as the transmitted light wavelength selection means of FIG.

FIG. 20 is an operation timing chart for explaining the operation of the conventional color image pickup apparatus.

[Explanation of symbols]

50 lens, 51 solid-state image sensor, 52 A / D converter, 53 digital signal processing circuit, 54 first memory circuit, 55 second memory circuit, 56 motion detection means, 5
7 control circuit, 58 1st D / A converter, 59 2nd
D / A converter, 60 subject table, 61 square object (subject), 62 round object (subject), 63 subtraction circuit, 64 comparison circuit, 65 recognition means, 66 judgment period setting means, 67 arithmetic circuit, 68 addition circuit , 69 third memory circuit, 70 comparison circuit, 71 recognition means.

Claims (5)

[Claims] 1. A lens, a solid-state image sensor for converting a subject image formed by the lens into an electric signal, an A / D converter for converting a signal obtained from the solid-state image sensor into a digital signal, and In a still image pickup device including a digital signal processing circuit for processing a digital signal converted by an A / D converter, a first image signal storing circuit stores a signal from the digital signal processing circuit.
Memory circuit, a second memory circuit for storing the signal read from the first memory circuit, digital signals sequentially read from the first memory circuit, and sequentially read from the second memory circuit. Motion detection means for inputting a digital signal to detect whether or not the subject is moving, and a state in which writing of the digital signal to the second memory circuit is permitted or prohibited in response to a control signal from the movement detection means. Control means for controlling the digital signal read from the first storage circuit, a first D / A converter for converting a digital signal read from the first storage circuit into an analog signal, and a digital signal read from the second storage circuit. And a second D / A converter for converting into an analog signal. 2. The first and second D / A converters are respectively connected to video display means for displaying a still image from an analog signal.
The still image capturing device according to. 3. The movement detecting means subtracts a digital signal read from the second storage circuit from a digital signal read from the first storage circuit, and a difference value from the subtraction circuit in advance. A comparing circuit for comparing with a set reference value, a recognizing unit for recognizing a change in the pattern of the control signal output according to the result of comparison by the comparing circuit, and a determining for setting a period for determining by the recognizing unit. The still image pickup device according to claim 1 or 2, further comprising: a period setting means. 4. The operation detecting unit subtracts a digital signal read from the first storage circuit from a digital signal read from the second storage circuit, and outputs an absolute value of the result. An adder circuit that sequentially adds the outputs from the arithmetic circuit; a third storage circuit that stores the added value added by the adder circuit and outputs the sum of the added values every set number of times; And a recognition circuit for recognizing a change in the pattern of the control signal from the comparison circuit. The still image pickup device according to claim 1. 5. The still image capturing apparatus according to claim 4, wherein the motion detecting unit further includes a determination period setting unit that sets a period to be determined by the recognizing unit.