JPS6150479A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To improve the chromaticity of the titled device by providing the 1st and 2nd color filter segments, halving a area of each photosensitive region to an area of one picture element and displacing the said segments to the photosensitive region in synchronization with the output operation of a video signal. CONSTITUTION:Two color segments per one picture element are arranged to a color filter 16 corresponding to an image pickup cell array 14. Bimorphs 20, 22 are connected respectively to pulse sources 34, 40. Two output pulses of the pulse sources 34, 40 have a phase difference of 180 deg. and the pulse width is equal to the field period. Both the pulse sources are controlled in synchronization with the drive of the image pickup device 12. Thus, a control circuit 60 applies pulses VH1, VH2 and VV1, VV2 of the pulse sources 34, 40 to the bimorphs 20, 22 in synchronization with the read of a video signal. Thus, two filter segments of each picture element are placed on a position converting the photodetector aperture of the image pickup cell alternately at each field period.

Description

[Detailed description of the invention] Yoshikuni Hara! The present invention relates to a solid-state imaging device, and particularly to a solid-state imaging device using a solid-state imaging device such as a DO3 or a CCD, and a color filter for color separation.

11. In the conventional solid-state imaging device, the L of the imaging cell array of the element is
A color filter is formed in which color filter segments are arranged in accordance with each imaging cell. This is formed by bonding a color filter to a device or by growing a filter layer on an element substrate. Therefore, all of these filters are configured integrally with the solid-state imaging device.

As a color reproduction method for such a color imaging device, various methods have been proposed, including the color arrangement of filters. The resolving power of a monochromatic imaging device is simply determined by the number of pixels arranged in the element, but in a color imaging device, the resolving power is determined by the color arrangement, and the reproducibility of one color also depends on the color arrangement. In the case of color, taking a colored thread filter as an example, the green (G) component contributes to resolution, and the blue (B) and red (R) components contribute to chromaticity.

Even in color imaging, resolving power is basically largely dependent on the number of pixels, and chromaticity has often been at the expense of resolving power.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art and provide a solid-state imaging device with improved chromaticity.

According to the present invention, there is provided a solid-state imaging device having an imaging surface in which photosensitive regions responsive to incident light are arranged two-dimensionally in correspondence with pixels, and a photosensitive device disposed covering the imaging surface. In a solid-state imaging device, the solid-state imaging device includes color filter means for color-separating light incident on a region, and control means for driving the solid-state imaging device to output a video signal by raster scanning, wherein the color filter means corresponds to each of the photosensitive regions. the first and second arranged as
color filter segments, each photosensitive area occupying at most half the area of one pixel of the imaging surface, and the solid state imaging device is further responsive to a control means to change the relative position of the color filter segment with respect to the photosensitive area. including displacement means;
The displacing means positions the first color filter segment on each photosensitive area during one field forming an image frame of the video signal in synchronization with the output operation of the video signal from the solid-state imaging device; A second color filter segment is positioned over each photosensitive area during the field.

Dog] 1 mackerel! Next, embodiments of a solid-state imaging device according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, in the embodiment of the solid-state imaging device according to the present invention, a housing 10 having an overall rectangular parallelepiped shape is used.
A solid-state imaging device 12 such as a MOS type or CCD type
is mounted with the two-dimensional imaging cell array 14 facing upward as shown. A color filter 16 is arranged above it, and its four corners are connected to a support 18 and a piezoelectric bimorph 2.
0 and 22, and is supported by the housing IO. The color filter 18 is a segment array 2 in which color filter segments are two-dimensionally arranged corresponding to the imaging cell array 14.
6. The distance between the filter 16 and the imaging cell array 14 is set to a predetermined value, for example, 5 by the spacer 24.
It is maintained at about ~500 pL11.

As shown, the two bimorphs 2o on the left have connecting wires 3
0, and the two bimorphs 20 on the right are connected by a connecting line 32 to a pulse source 34. Similarly, the lower two bimorphs 22 are connected by connecting wires 36.
The upper two bimorphs 22 are also connected to a pulse source 34 by a connecting line 38.

The pulse source 34 generates a voltage pulse V)II having a waveform as shown in FIG. 3, for example, at its output 3o.
2, a voltage pulse VH2 having a waveform whose phase is reversed by 180' is generated. The pulse width T is equal to the field period of the video signal, and the duty ratio is 1/2.9If this device outputs a standard television system video signal, for example, this pulse @T is equal to the field period of the video signal, and the duty ratio is 1/2. 6o milliseconds. The pulse height v1 is adjusted by a semi-fixed resistor 44 connected to a predetermined voltage 42, and the DC shift amount v2 is adjusted by a semi-fixed resistor 48 connected to a predetermined voltage 46.

Similarly, the pulse source 40 has a fourth
A voltage pulse VVI having a waveform as shown in the figure is generated, and a voltage pulse VV2 having a waveform whose phase is reversed by 18 degrees is generated at its output 36. The pulse width T is the same as that of the pulse V) II described above. The pulse height v3 is
° by a semi-fixed resistor 52 connected to a predetermined voltage 5o
The DC shift amount v4 is adjusted to a predetermined voltage 5.
4 and a semi-fixed resistor 58 connected to 4. Both pulse sources 34 and 4o are controlled by a control circuit 60 in synchronization with driving of the imaging device 12.

The bimorph 20 adjusts the position of the filter 16 in the horizontal (H) direction. In this embodiment, the filter 16 moves in the horizontal direction in response to the voltages vH1 and V)12 applied to the bimorph 20. Therefore, when the voltages V)II and VH2 are applied in a pulsed manner at the field frequency, the filter 16 vibrates from side to side accordingly.

Similarly, bimorph 22 is vertical (v) of filter 16.
This is to adjust the position in the direction. In this embodiment, the filter 18 moves in the vertical direction in response to the voltages VVI and VV2 applied to the bimorph 22. 1. Therefore, when the voltages VVI and VV2 are applied in a pulsed manner at the field frequency, the filter 16 vibrates up and down accordingly.

These applied voltages V) II, VH2t-IJ: and VV
The DC components v2 and v4 of the I, VV2 (7) soles are relatively adjusted by the semi-fixed resistors 48 and 56, thereby adjusting a specific position of the segment array 26 of the filter 16 to a specific position of the imaging cell array 18. In other words, the origin of both can be aligned. Also, the applied voltage VHI, VH2? Jl-VVI,
VV2 (7) Pulse height Vl and v of the pulse F
3 are relatively adjusted by semi-fixed resistors 44 and 52, thereby causing segment array 26 of filter 16 to
The angle of rotation about the axis perpendicular to the imaging cell array 16 can be adjusted.

Typically, during device assembly, a rough alignment of filter segment array 26 to imaging cell array 14 of device 12 is performed. More precise matching is achieved by adjusting these voltages v1-v4.

In this fine alignment, the filter segment array 26 can be correctly aligned positionally with respect to the imaging cell array 14 as described above.

In the imaging cell array 26, in this embodiment, imaging cells +00 (FIG. 5) corresponding to 380 pixels in the horizontal (l) direction and 480 pixels in the vertical (v) direction are arranged in a matrix. In FIG. 5, two adjacent cells +
00 is shown. The surface of the cell 100 is shielded from light by a metal vapor deposition layer 102 made of, for example, aluminum, and an optical aperture 104 is formed in a portion thereof. At the current state of the art, the proportion of the optical aperture in one pixel of an imaging device element is at most about 20 to 50%.1 Usually it is about 30% or more. A device is advantageously used, for example, in which the aperture 104 in horizontal length is less than or equal to 1/2 the pixel pitch.

In the color filter 16 disposed on the - side of the imaging cell array 14, two color segments (110a and 110b) are arranged per pixel in this embodiment. As can be clearly seen from FIG. 6, the segments 110a and 110b of the 2-ilter segment array 26 are arranged at a pitch of /2 of the pitch at which the imaging cells +00 are arranged. Therefore, the size of these segments (1IOa or 110b) can cover at least the area of the light receiving aperture 104.

As shown in FIG. 1I, a microlens 120 may be formed over the filter 16, which includes filter segments 110a and 1, as shown.
Lens segment according to the array pitch of 10b) 12
2a and +22b are arranged. Each of the lens segments 122a and 122b has a predetermined refractive index distribution, and is configured such that the light incident on each segment is focused on the imaging surface of the imaging device. As a result, the effective aperture ratio of the imaging cell 100 is relatively improved and the occurrence of smear components is reduced, so that even higher sensitivity can be achieved and color moiré can be reduced.

An example of the arrangement of color segments of the color filter 18 is partially shown in FIGS. 8 and 9. In both figures, fruit,
II-t'8 t'''f'' 911°ohss-pv
li;it-, "i.e. a square area 110a or 110 indicating an imaging cell and further delimited by a dotted line.
b indicates one filter segment of the color filter 16.

In the example shown in FIG. 8, yellow (Ye), green (G), cyan (Cy), and magenta (Kg) are arranged horizontally shifted by 1/2 pixel pitch in each horizontal row. Also the 9th
In the example shown,! (G), red (R), and blue (B) are arranged so that each pixel always includes G, as shown in the figure.

By the way, in the operating state, the control circuit 6o drives the pulse sources 34 and 4o in synchronization with the readout of the video signal from the imaging device 12 in the field period, and outputs the pulse voltages Vold, V)12 and VVI from them.

When VV2 is applied to bimorphs 2o and 22, respectively, in one field period, namely the A field, one of the two filter segments of each pixel;
For example, as shown in FIG. 6, when the filter 16 is driven in the direction of the arrow and ll0a is synchronized with light reception, that is, in the B field, the other filter segment, ie, in this example, 1Iob is the light reception aperture as shown in FIG. Part +04
Take a position that covers the This is repeated sequentially for each frame.

In this embodiment, the imaging device 1
The video signal is read out from 2 to 2 horizontal rows at a time. For example, in the filter array shown in FIG. 8, in the A field, the filter 18 is driven in the direction of arrow H2 and
Since a covers the aperture 104 of each imaging cell +00, the color signals are summed every two horizontal rows and are sequentially output.

For example, for the first and second rows from the top of the figure, Y
e and Mg, and Cy and G are respectively summed, arranged spatially alternately, and read out sequentially. Further, for the third row and II4 row, Ye and G, and Cy and Kg are summed, respectively, and are spatially alternately arranged and sequentially read out. Thereafter, similar reading is performed for two horizontal rows in sequence.

Next, in the B field, since the segment) 110b covers the opening 104 of each imaging cell 100, the segment +1
The color signals of 0b are summed every two horizontal rows and sequentially output. For example, in the second row and w43 row from the top of the figure, Ye and xg, and Cy and G are summed, respectively, and are spatially alternately arranged and read out sequentially. Further, regarding the fourth and fifth rows, Ye and G, and ay and M are summed, respectively, and are spatially alternately arranged and read out sequentially. Thereafter, similar reading is performed for two horizontal rows in sequence. In this way, in the complementary color filter array, two types of color information can be obtained from the same cell 100, so color reproducibility is improved and single-color moiré is reduced.

Similarly, in the filter arrangement of FIG. 9, in the A field, segment 11Qa covers the aperture +04 of each imaging cell +00, so the color signals are summed every two horizontal rows and sequentially output. For example, G and B and R and G are summed, respectively, in the first and second rows from 1H of the same figure, and are spatially alternately arranged and read out sequentially. Further, regarding the third and fourth rows, G and B, and R and G are summed, respectively, and are spatially alternately arranged and read sequentially. Thereafter, similar reading is performed for two horizontal rows in sequence. As will be seen from now on, one pixel signal always includes a G component, and the color information is twice that of the case where a conventional primary color filter array is used. Therefore, the resolution is approximately doubled and the color reproducibility is also significantly improved.

Next, in field B, segment) 110b covers the opening 104 of each imaging cell +00, so segment) 11
The color signals of 0b are summed every two horizontal rows and sequentially output. For example, regarding the second and third rows from the top of the figure, G,! - R1 and B and G are summed respectively;
They are spatially arranged in an intersecting pattern and read out sequentially. Also the fourth
For the row and the fifth row, G and R1 and B and G are summed, respectively, and are spatially alternately arranged and read out sequentially. Thereafter, similar reading is performed for two horizontal rows in sequence.

An example of a circuit that reads a video signal from the imaging device 12 and outputs color separation signals G, B, and R is shown in FIG. In this case, a read clock is supplied to the imaging device 12 from the control circuit 60 through the signal line 62. In response to this, the imaging device 12 outputs the aforementioned video signal to its output terminal 64. The output 84 is connected to a low pass filter (LPF) BB and a band pass filter (BPF) 8B, and the signal frequency-separated by these is G.

They are output as B and R to output cuffs 0.72 and 74, respectively.

Note that the embodiments described here are for explaining the present invention, and the present invention is not necessarily limited thereto, and modifications and variations that can be made by those skilled in the art without departing from the spirit of the present invention. Modifications are within the scope of this invention.

For example, in this embodiment, the color filter is displaced, but the point is that the relative position of the color filter segment with respect to the imaging cell only needs to be displaced, so the configuration is such that the color filter is fixed and the imaging device is displaced. may also be used in the filter segment.
1 arrangement is not limited to the illustrated embodiment, but the present method can be effectively applied to most of the methods proposed so far with a slight modification. Further, although the field storage mode has been described as an example, the present invention can of course also be effectively applied to a frame storage method. It goes without saying that the video signal can be applied not only to the NTSC standard color television system but also to other systems such as PAL and SECOM.

肱-1 As described above, according to the present invention, the resolving power is increased with primary color filters and the color reproducibility is increased with complementary color filters compared to the conventional ones.Therefore, a solid-state imaging device with improved chromaticity is achieved. can be provided advantageously.

[Brief explanation of the drawing]

wIJ1 is a schematic block diagram showing an embodiment of the solid-state imaging device according to the present invention, FIG. 2 is a diagram showing a cross section taken along the dashed-dotted line 1111 in FIG. 1, and FIGS. 3 and 4 are shown in FIG. 1. FIG. 5 is a waveform diagram showing an example of a pulse waveform generated from a pulse. FIG. 5 is a diagram partially showing two adjacent imaging cells in the embodiment of FIG. 8 and 9 are cross-sectional views partially showing the cross sections of a color filter and an imaging cell for explaining the operation of the embodiment shown in FIG. 1. FIGS. FIG. 10 is a diagram partially showing an example of the arrangement of segments. FIG. 11 is a sectional view similar to FIG. 146 showing another embodiment of the present invention. -)'s; 12, , solid-state imaging device 14, , imaging cell array 20.22. , Piezoelectric Bimorph 2B, , Color Filter Segment Array 34.40.
, pulse source 100, , imaging cell 110a, , filter segment +20. , , Microlens 122a , , Microlens Segment Patent Applicant
Fuji Photo Film Co., Ltd. C. Takao Katori -＼ 1 Qin 2 Koushun, l] M Vl &5 Zumakurozu - H/ Figure a > Q Figure 1 O Kunihada ll mouth

Claims (1)

[Claims] 1. A solid-state imaging device having an imaging surface in which photosensitive areas responsive to incident light are arranged two-dimensionally in correspondence with pixels; In the solid-state imaging device, the solid-state imaging device includes color filter means for color-separating the incident light of the image sensor, and control means for driving the solid-state imaging device to output a video signal by raster scanning, wherein the color filter means separates the incident light into each of the photosensitive areas. the solid-state imaging device has first and second color filter segments arranged correspondingly, each photosensitive region occupying at most half the area of one pixel of the imaging surface, and the solid-state imaging device is responsive to the control means. and a displacement means for changing the relative position of the color filter segment with respect to the photosensitive area, the displacement means forming an image frame of the video signal in synchronization with the output operation of the video signal from the solid-state imaging device. a first color filter segment is positioned over each photosensitive area during one field of the process, and a second color filter segment is positioned over each photosensitive area during the other field. Solid-state imaging device. 2. The device according to claim 1, wherein the displacement means includes a piezoelectric bimorph movably supporting the filter means, and the control means pulses the piezoelectric bimorph in response to the field period. A solid-state imaging device characterized by applying a voltage of 1. 3. The apparatus according to claim 2, wherein the displacement means includes adjustment means for adjusting the waveform of the pulsed voltage to align the color filter means with the imaging surface. Imaging device. 4. The solid-state imaging device according to claim 1, wherein a light-shielding film is formed on the imaging surface to block incident light except for the photosensitive area. 5. A solid-state imaging device according to claim 1, wherein the color filter means includes microlens means for condensing incident light in correspondence with the color filter segments.