JPH01103076A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To quicken the decision of pickup various parameters by transferring a signal charge generated in a vertical CCD at photometric stage, detecting it by a diode to obtain a photometric signal and discharging the signal charge generated at the outside of the range of photometry through the drain. CONSTITUTION:The scanning of a photodetector element 1 at the photometric stage is applied at a high speed and trigger switches S1, S2 are interlocked with the shutter of an electronic still camera. When the shutter is opened, an operational amplifier and a capacitor C constitute a current integration device to integrate a photometric signal BA, which is fed to a switch circuit 121. The gate circuit 123 is switched by a pulse signal 122 to send the output signal of the switch circuit 121 to a binary counter 124 and the digital output based on the photometric signal BA is fed to a central processing unit 125, which applies prescribed calculation to various pickup factors such as a white balance signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state imaging device comprising a charge storage device, and particularly to a technique suitable for use in determining imaging parameters at high speed.

[Prior art]

Conventionally, imaging devices such as electronic cameras have been equipped with interline transfer technology.
fer) type solid-state imaging devices, it is necessary to determine photographing parameters such as exposure, focus, and white balance before actually taking pictures. It is well known that photometry is performed by repeatedly reading out the signal charges as necessary.

[Problem that the invention seeks to solve]

However, as solid-state imaging devices have become more pixel-rich and denser in recent years, it has taken a long time to perform photometry processing before image capture, leaving users with a feeling of lag in device operation.
There were problems such as giving

In particular, in a solid-state imaging device with a conventional structure, a horizontal CD provided at one end of a vertical CCD is commonly used to read out photometric signals and normal image output, but the horizontal CCD has a slow signal charge transfer speed. Therefore, there is a problem in that the time required for photometry processing is uniquely determined by the transfer speed of the horizontal CCD.

In particular, in solid-state imaging devices with a conventional structure, a horizontal CCD provided at one end of a vertical CCD is commonly used to read out photometric signals and normal image output, but the horizontal CCD has a slow signal charge transfer speed. Therefore, there is a problem in that the time required for photometry processing is uniquely determined by the transfer speed of the horizontal CCD.

The present invention has been made to solve the above technical problems, and its purpose is to provide a solid-state imaging device that can speed up the determination of photographic parameters such as exposure, focus, and white balance. .

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a frame interline type solid-state imaging device that uses light sensing and reception performed through a striped color filter in a vertical CGD photometry range. A detection means such as a diode for detecting the signal charge generated based on the photometry range and a discharge means such as a drain for discharging the signal charge generated based on the light sensing performed outside the photometry range are provided, and the signal detected by the detection means is provided. This device is configured to determine photographing parameters prior to normal image photographing based on electric charges, that is, photometric signals.

[For production]

According to the above-mentioned means, the signal charges for determining the photographing parameters can be obtained regardless of the horizontal CCD that obtains the normal image output, and the operation for determining the photographing parameters performed prior to the ordinary image photographing can be enhanced. It can be speeded up.

〔Example〕

Hereinafter, one embodiment of the solid-state imaging device according to the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram schematically showing a frame interline type solid-state imaging device to which the present invention is applied.

Note that illustration and description of the charge storage section will be omitted.

The light-receiving elements l are arranged in a matrix as described later, and one block is shown as a vertical CCD 2 that vertically transfers the signal charge of the light-receiving element.One end of the vertical CCD 2 A horizontal CCD 3 for horizontally transferring a normal image output is arranged, and the signal charge for each horizontal row transferred to the horizontal CCD 3 is driven in two phases by a transfer electrode, and is sent to a buffer amplifier 4. read out via

On the other hand, at the end of the vertical CCD 2 facing the horizontal CCD 3, a drain/sense separation circuit 5 and a sense diode 6, which will be described later, are arranged.

A drain/sense separation circuit 5 (hereinafter referred to as a separation circuit) separates a photometric signal within the shaded photometric range from signals in other areas, and a sense diode 6 separates the photometric signal from the separated photometric signal. It detects the same color signals of the three primary colors of light, R (red), G (green), and B (blue).

Next, the separation operation and the combination of same color signals will be explained with reference to FIGS. 2 and 3.

In Figure 2, 11.12...IN, 21.22.
...2N, 31.32...3N, 41.42...4
N is an image signal diode, which constitutes the light receiving element.

R, G, and B in the figure correspond to the vertical CCD 2, and the colors R (red), G (green), and B (blue) correspond to the three primary color stripe type color filters (not shown). A signal, in other words, a signal charge that becomes a photometric signal is generated. R, G, B
The vertical CCD 2 shown by generates signal charges shown by black circles during photometry, and transfers them upward in FIG. 2 by clock signals φ□ to φA4.

Note that during normal image shooting, signal charges generated from the image signal diodes 11 to 4N are transferred as shown by white circles. At this time, since the charge in the vertical CCD 2 is emptied by the transfer during photometry, the charge for the image signal is transferred at high speed, and signal deterioration can be reduced.

The gate 101 controls the transfer of photometric signals,
The circuit is controlled to be open during photometry, and the circuit is controlled to be closed when obtaining normal image output.

The drain 102 is for discharging photometric signals, and is provided for discharging color signals unnecessary for photometry.

A gate 104 and an output gate 103 control a photometry signal that is continuously sent to a sense diode 6, which will be described later, and are open circuits during photometry and closed circuits when obtaining a normal image output.

Further, the sense diode 6 is provided corresponding to the photometric range as shown in FIG. 1, and the symbol "n" attached to the sense diode 6 and the drain 102 indicates the polarity and concentration of the semiconductor.

During photometry, the gate 101 is controlled to open circuit and the photometry signal is transferred to the drain 102. At this time, since the sense diode 6 is arranged at a position corresponding to the photometric range, the gates 103 and 104 are controlled to be open circuits in this range. Therefore, photometric signals generated within the photometric range are transferred to the sense diode 6, but all photometric signals outside the photometric range are discharged by the drain 102. That is, the gates 101, 103, 104, the drain 102, and the sense diode 6 constitute a separation circuit.

The sense diode 6 is connected by a metal wire so that R, G, and B photometric signals can be combined for each signal of the same color. Therefore, each time the light-receiving element 1 is scanned, photometric signals RA, GA, and BA of the three primary colors are obtained.

The photometric signals R4, GA, and BA are signals that determine photographing specifications, and are subjected to predetermined signal processing by the signal processing circuit 100. The circuit configuration including the signal processing circuit 100 is known to those skilled in the art as a circuit for obtaining an AE multiplied signal, and its outline will be explained below.

During photometry, scanning of the light receiving element 1 is performed at a high speed of, for example, about 1/1000 sec. The trigger switches St and Sz are linked to the shutter of the electronic still camera, and when the shutter is opened, the switches S and S are opened and the switch St is closed. C,
When the ten ivy is opened, that is, during photometry, the operational amplifier and capacitor C constitute a current integrator, and the photometry signal BA
is integrated and supplied to the switch circuit 121.

The gate circuit 123 is opened and closed by a pulse signal supplied from the pulse generator 122, and transmits the output signal of the switch circuit 121 to the binary counter 124. Binary counter 124 supplies a digital output based on photometric signal BA to central processing unit 125.

The above-described circuit operation is similarly performed for the photometric signals Gp, , Rt, and the central processing unit 125 performs predetermined calculations based on the respective digital outputs to generate photographing specifications such as a white balance signal. do.

Note that when the switch circuit 103 is triggered during the first scanning, the diaphragm formed by the mechanical structure is further narrowed down, the measurement range is reduced, and photometry is performed again to determine the optimal measurement range. If the switch circuit 103 is not triggered even after scanning several thousand times, the mechanical aperture is enlarged, the measurement range is enlarged, and photometry is performed again.

On the other hand, when performing normal image shooting, the gate circuit 101 is controlled to be a closed circuit, and the transfer gate 1
05 is controlled to open circuit. During the photometry period, the signal charges accumulated in the image processing diodes 11 to 4N are transferred to the vertical CCD as shown by the arrows, and are sequentially transferred downward in FIG. 2 by the action of the clock signals φAt to φ□. The signal charges are sequentially accumulated in the charge storage circuit 106 via the transfer gate 105 and then read out via the horizontal CCD 3 and the buffer amplifier 4.

〔Effect of the invention〕

As described above, according to the frame interline type solid-state imaging device of the present invention, signal charges generated in the vertical CCD during photometry are transferred and detected by diodes to obtain photometry signals, and signals generated outside the photometry range are transferred. Since the structure is configured so that the charge is discharged by the drain,
Since the overshadowing parameters are determined based on the signal charges obtained from the photometry range, the operation for determining the imaging parameters can be sped up. Further, by transferring the signal charge accumulated in the image signal diode during the photometry through the vertical CCD, it is possible to reduce the deterioration of the image signal, that is, the exposure to light during the transfer.

4. Detailed Description of the Invention Figure 1 is a schematic configuration diagram showing an embodiment of a solid-state imaging device according to the present invention, Figure 2 is an enlarged view of the main part of a light receiving element, and Figure 3 is a circuit diagram of a separation circuit. be.

(Symbols in the figure) 1... Light receiving element, 2... Vertical CCD, 3...
...Horizontal CCD, 4...Buffer amplifier, 5...
・Separation circuit, 6...Sense diode, 11~4N
...image signal diode, 101, 103. 1
04...Gate, 102...Drain, Ra, GA, Ba...Photometric signal.

Figure 1 D, 'S2 figure Figure 3 White Paranmata (1 draw)

Claims (1)

[Claims] Light-receiving elements arranged in a matrix, vertical CCDs that are attached to each vertical column of the light-receiving elements and that transfer signal charges and receive light using an m-phase driving clock signal; In a frame interline type solid-state imaging device comprising a horizontal CCD provided at one end to transfer the signal charge in the horizontal direction to obtain a normal image output, a photometric range of the vertical CCD is provided at the other end of the vertical CCD. a detection means for detecting signal charges generated within the vertical CCD, and a discharge means for discharging signal charges generated outside the photometric range of the vertical CCD separated from the signal charges detected by the detection means; A solid-state imaging device characterized in that it is configured to determine photographing specifications based on the signal charge detected by the detection means.