JPS5952973A - Image pickup element and image pickup device - Google Patents

Abstract

PURPOSE:To obtain a signal which is suitable for reproducing a still picture record, by separately outputting signals of an odd number line and an even number line of an image pickup element and obtaining information of two fields from information of one picture. CONSTITUTION:A shift registers 2a scans only odd number lines and another shift register 2b scans only even number lines and the outputs of the odd number lines and even number lines are outputted through separate circuits after passing through amplifiers 6a and 6b, respectively. When shift registers 2a and 2b are driven in parallel with a time interval of 1/2 horizontal scanning period between them in an image pickup device, the output of the device can be outputted synchronously to TV signals one field by one field. Moreover, since information of two fields formed simultaneously when the two outputs are read out at the same time can be obtained, this device is suitable for reproducing a still picture record.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-Y address type imaging device suitable for still image recording and an imaging device using this device.

In conventional X-Y address type image sensors, checkered pattern color filters are often used as color filters attached to the sensor to improve sensitivity and horizontal resolution, as shown in Figure 1. There is.

The illustrated example consists of four color filters: Cy (Nan), Yo (*), W (transparent), and G (green), and by adopting complementary color filters, the light transmittance of the filter is improved, and as a result, The sensitivity of the sensor has also been improved.

In the figure, reference numeral 1 denotes a horizontal shift register which performs horizontal scanning by sequentially turning on two reading transistors 3 at a time. Reference numeral 2 denotes a vertical shift register, which vertically scans a transistor 4 for reading an electric signal from a photodiode 5 as a photoelectric conversion means, for example.

Here, the photodiodes 5 form horizontal rows and vertical columns, and the register 2Fi has a function of selecting a row to be read out, and the register 1 has a function of selecting a column to be read out.

Moreover, for each photoelectric conversion means 5, Cy % G 1
Light enters through either Y8 or W color filter,
The output of the photoelectric conversion means 5 equipped with the same color filter is outputted from the sensor via a common output line. Further, the output of the sensor configured in this manner is subjected to correlation processing as described below in a signal processing circuit (not shown).

That is, the luminance signal Y is obtained by adding the signals of two vertical picture elements.

In Fig. 1, Y=Cy+Y,=W10=R+2G+BAlso, the color signal is also calculated by vertical correlation as R=(Y8+W)-(c+cy) B=(W-cy)-(Yo1G) Obtain signal and B signal.

However, in such conventional sensors, one line's worth of signals is obtained from two vertical lines, and although the horizontal resolution and sensitivity are improved, the so-called field skip method recording and playback is required for still image playback. If this is done, the information of one field will be reproduced twice, resulting in a lower vertical resolution.

Furthermore, if the next field is imaged after recording J fields on a recording medium, recorded on another track, and played back, the subject will be blurred when photographing a moving object.

It is an object of the present invention to provide an improved imaging device that can obtain signals suitable for recording and reproducing still images using such an X-Y address type image sensor.

Therefore, in the present invention, a color filter that does not require vertical correlation is combined with an imaging device using an X-Y address type image sensor.

In addition, the signal of the odd line of the X-Y address type Senna,
Since the output lines are connected so that the even-numbered line signals can be output separately, the information for 2 lines can be separated from the information for 1 line obtained by one imaging.

Furthermore, in such a wiring configuration, an adding means capable of adding up the even number line output and the odd number line output pair by pair is provided, and by selectively operating this adding means, an X-Y address type image sensor can be used. In this case, it is also possible to combine one-time imaging information into one field's worth of information. In addition, in the case of nickel, there is also the effect that the sensitivity of the Kd sensor is approximately doubled.

The present invention will be described in detail below based on examples.

Note that the same reference numerals as in FIG. 1 represent the same elements.

In the figure, 2a is a shift register for selecting information on odd rows, and sequentially scans only odd rows, for example, 1, 3.5, . . . . 2b is a shift register for sequentially scanning even-numbered rows.

Further, 6a is an amplifier for amplifying and outputting the output from each pixel in the code-numbered row, and 6bfd is an amplifier for amplifying and outputting the output from each pixel in the even-numbered row.

One of the main features of the present invention is that the output lines are connected so that odd-numbered row information and even-numbered row information can be read out in separate systems. Further, as shown in the figure, the color filter applied to each photoelectric conversion means, that is, the picture element, is different from the conventional one and is constituted by, for example, a stripe filter that does not utilize vertical correlation. Therefore, the processing circuit for processing the signals of each line and the processing circuit for adding and processing the signals of two lines can be partially shared, which simplifies the configuration.

In addition to the stripe filter, the same effect can be obtained even with a modulation type filter.

Note that the force 2 filter applied to the imaging device of the present invention may be a filter that utilizes vertical correlation, such as a mosaic filter, but in that case, the horizontal resolution may be slightly reduced when reading out each line signal independently. There are downsides.

Another disadvantage is that the processing method must be changed depending on whether one line is read out one line at a time or two lines are added up and read out. On the other hand, when the signals are added and output in this way, the horizontal resolution is improved and the sensitivity is also improved.

Oka, in this embodiment, by providing the registers 2a and 2b, for example, it is easy to form a shift of 1/2 horizontal scanning period and prevent the occurrence of skew distortion. It is also possible to provide such a function with a single register. However, in that case, there is a drawback that the control pulses to the registers are extremely complicated.

FIG. 3 is a block diagram showing an example of the configuration of an imaging device according to the present invention, where ■D is an imaging surface, 1 is a horizontal shift register, 2a,
2b is a vertical shift register for odd lines and even lines, respectively.

7 is a drive circuit for supplying drive pulses to each register;
Reference numeral 8 denotes a mode switching circuit as a selection means for supplying a mode switching signal to the drive circuit, and the mode switching circuit has a first mode switching circuit for reading out the stored information for one time by dividing it into two fields. mode and a second mode for reading accumulated information as one field.

19 is a switch that changes according to the instruction from the mode switching circuit 8; 9 is an addition circuit for adding the outputs of odd and even rows; A processing circuit for forming signals and luminance signals; 11 is a recording circuit for converting the output of this processing circuit into signals suitable for recording; 12a and 12b are recording heads, respectively, which output signals to a recording medium (not shown); record.

Since the VC is configured in this way, when the first mode is selected by the mode switching circuit 8, the image pickup unit ID is shielded from light by a shutter (not shown) after accumulation is performed for a predetermined time, and then shifted by the drive circuit for odd numbers. By driving the register 2a and the even shift register 2b in parallel with a shift of, for example, 1/2 horizontal scanning period, the information on the odd rows and the information on the even rows are guided to the processing circuit 10 via the a terminal of the switch 9. After the information on the odd rows and the information on the even rows are subjected to signal processing in the processing circuit 10, they are respectively recorded on separate tracks on the recording medium by the heads 12a and 12b via the recording circuit.

In addition, when the second mode is selected by the mode switching circuit 8, light is always allowed to enter the imaging unit ID without using a shutter, and odd and even rows are read out as a pair, two rows at a time. , registers 2a and 2b are driven in synchronization.

Also, by switching the switch 19 to the "on" side at this time, the adder 9 adds the information on the odd rows and the information on the even rows that are read out at the same time, and adds the information to the adder 9 via the processing circuit 10 and the recording circuit 11. Recording is performed on one track of the recording medium using two heads 12a.

FIG. 4 is a diagram showing an example of the configuration of the processing circuit 10, in which 13 is an adder, 14 is a low-pass filter with a cutoff frequency of about 3 MHz, and 15a to 15c are filters with a cutoff frequency of 5.
Low pass filter of about 00KHz to I MHz, 1
6 is a subtracter, and 17 is a process circuit. With this configuration, the R,
After adding all the G and Cy multiplied signals, the luminance signal Y is formed by passing it through a low-pass filter.For each color signal, after cutting the high frequency components, the R signal is left as it is, and Fi (Cy-G) is generated from the Cy and G signals. A B signal is formed by the calculation, which is converted into a Y signal and a color difference signal in the process circuit 17 and output.

As explained above, according to the present invention, it is possible to obtain information for two fields formed simultaneously from an X-Y address type image sensor, and it is also possible to output one field at a time in synchronization with a TV signal. can.

Furthermore, when outputting in synchronization with the FV signal, the sensitivity of the element is improved because information from a plurality of rows is added.

Furthermore, since the odd-numbered rows and even-numbered rows are read out in parallel and recorded simultaneously by the two recording means, the recording speed is increased. In addition, the time required for track switching such as -.rad shift becomes unsettling.

In addition, since the odd field readout output and the even field readout output of the image sensor are connected so that they can be obtained independently of each other, it is possible to obtain the odd field signal and the even field signal in parallel. The signals of each field can be recorded simultaneously by the two recording means.

In addition, since it uses a stripe-type or modulation-type color filter, it has many advantages, such as the ability to share the signal processing circuit when processing signals one line at a time or by adding multiple lines. be.

[Brief explanation of drawings]

Figure 1 shows the + of the conventional MO8XX-Y address type image sensor.
FIG. 2 is a diagram showing an example of an ItS configuration, FIG. 2 is a diagram showing an example of an imaging element for an unexploded IJJ, FIG. 3 is a diagram showing an example of an imaging device of the present invention, and FIG. 4 is a diagram showing an example of a signal processing circuit. It is a diagram. 1...Horizontal shift register 2...
・・・・・・・・・Vertical shift register 2a・・・・
...Shift register 2b for odd rows...
・・Shift register 5 for even rows・・・・・・・・・・・・・
-Photoelectric conversion means (pixel) 9 Adder patent applicant Canon Corporation

Claims (2)

[Claims] (1) In an image sensor having a plurality of photoelectric conversion elements constituting rows and columns and a plurality of output lines for respectively reading out the photoelectric output of each element, the photoelectric conversion elements in odd-numbered rows of the image sensor An image sensor characterized in that an output line for reading information and an output line for reading the information of even-numbered photoelectric conversion elements are made independent of each other. (2) +MPl photoelectric conversion elements forming + and III rows and columns, odd row output lines for reading out information on photoelectric conversion elements on odd rows, and even numbered output lines for reading out information on photoelectric conversion elements on even rows. an image sensor having row output lines independently, an adding means capable of adding and outputting an output via the output line of the previous ML odd-numbered rows and an output via the output line of the even-numbered rows, and the adding means. An imaging device having a selection means for selectively operating the image pickup device.