JPS5843671A - Frame transfer type image pickup element - Google Patents

Abstract

PURPOSE:To store a still picture image information at a low speed, in a digital memory of large capacity, by convert-processing a picture image information signal of a high speed to a low speed signal once through a buffer memory incorporated in an image pickup element itself. CONSTITUTION:When at least 2 or more store parts 11-14 of an image pickup element such as a frame transfer type CCD, etc. are constituted of cascade, picture image information of the number of sheets corresponding to the number of provided store parts can be stored in a short time. In this way, when the store part having the image pickup element and a buffer memory function are constituted on the same chip, it is unnecessary to particularly add an external buffer memory, and also it becomes possible to write in a main digital memory at an optional speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved structure of a frame transfer type CCD 8% image sensor.

In a field-sequential color imaging device, when output signals from one sensor are stored for a relatively long period of time, a filter disk 1 having multiple colors is generally used as shown in Fig. 1.
For each field output from the m-image element 2 via By configuring the data to be stored in the relatively slow main memory 4, it is possible to use one slow but large-capacity memory. In this case, in particular, the output signals of the six primary colors 1 etc. from the field sequential type imaging device may be outputted sequentially.The memory element that sequentially stores these signals at a high speed may be, for example, a charge transfer type analog memory or a multi-speed writeable memory. However, the number of bits of these buffer memories must be at least six times the number of pixels to be captured, and since the horizontal clock frequency of the image sensor is relatively high, these buffer memories are also It has the disadvantage that it inevitably has to be high speed.

It is also extremely easy to achieve these memories in a compact size. The purpose of the present invention is to eliminate these drawbacks.The present invention is intended to solve this problem by converting the originally high-speed freeload information signal into a low-speed signal through the buffer memory built into the image sensor itself. This allows still image information to be stored in digital memory at low speed.

The present invention will be explained in detail below. FIG. 2 is a diagram showing an embodiment of the present invention, and 11 is a frame tri-y
fiCCD f) Light reception is, 12. 13 and 14 indicate storage sections to which charges are sequentially transferred, and numeral 15 indicates a read register section for reading out information from one of the storage sections at a low speed.

Φ＾1−, J＾4. g@1~佽4. ΦC1~ei4. @0
1 to 4. The input ends of the transfer locks at hoods 1 to 4 are shown at 11 to 15, respectively. In the above configuration [,
When optical information is input to the light receiving section, the information is converted into power and after a certain amount of time has elapsed, the input terminal Φ^1-JA4
Even if the received light information is read out from K and immediately stored in the storage unit 12, in a field sequential type imaging device, this received light information is transferred from 11 to 12 every time the field is changed, and then transferred sequentially from 12→, 16→14→15. It is configured so that The transfer time from 11 to 14 is determined by the field switching time, and the small ranking period provided during the field period, that is, field *1! Lm carrier, 5-(
・Transfer will be performed during the portion corresponding to the switching period of the first filter.

On the other hand, since optical information of three colors is generally required to form the Idii surface, for example, B, G, and R charges are accumulated in the accumulation sections 12 to 14, respectively.

All transfers from 11 to 14 are performed during the field blanking period, so the distance in one period ranges from several mm to several 1.
Since it takes a value of 0m5, it is operationally stable (it is stable.The output signal from this element is converted into a charge and voltage by the preamplifier 16 and output, but this signal is written to a low-speed memory. At this time, the read speed can be freely changed by appropriately selecting the clock frequency of the read register 15.

Next, FIG. 3 shows a simpler and more compact version of the embodiment shown in FIG. It also has a storage function.

By constructing the gate in this way, the size of the chip can be reduced, and -1111? ) It has the effect of being inexpensive.

　　　　□・１′１・、.

As explained above, frame transfer type C
By forming at least two or more storage sections of a CD or other camera element in cascade, it is possible to store a number of pieces of information corresponding to the number of storage sections provided in a short time. By configuring the storage unit with the CCD and buffer memory functions on the same chip in this way, it becomes possible to write to the main digital memory at any speed without adding any external buffer memory. , IWI-
By simply providing an extra storage section on the wafer compared to the conventional frame transfer CCD chip, it becomes possible to easily create a field sequential imaging device in a small size. As ^
This has the effect of making it possible to obtain good image quality without using elements that can operate quickly.

[Brief explanation of the drawing]

Figure 81 is a block diagram of a still video imaging device using a four-bar image carrier element, Figure 2 is a diagram showing an example of the structure of a frame transfer type COD element according to the present invention, and Figure 3 is a diagram showing an example of the structure of a frame transfer type COD element according to the present invention. Another example is -. 11 is a light receiving section, 12 to 14 are storage sections, 15 is a read register section, and 16 is a preamplifier. Patent applicant Canon Co., Ltd. ψ-~9-Ima 1 Pk4'b-Yoi 1

Claims (1)

[Claims] A frame transfer type high-speed i-device consisting of a light receiving section, two or more cascade-connected storage sections, and a signal readout section.