JPS62171264A - Image sensor - Google Patents

Abstract

PURPOSE:To obtain an inexpensive image sensor by using the bulk element of simple structure such as a CdS or a photodiode as a device constituting a photosensor so as to combine a general photosensor and a liquid crystal shutter. CONSTITUTION:In an image sensor drive circuit, a liquid crystal drive circuit 10 generates a sequential pulse driving a liquid crystal shutter 14, a data processing circuit 11 processes a picture signal obtained from the photosensor 13, an output circuit 12 incorporates plural amplifiers A1..., and a timing signal generating circuit 15 is used. A control signal from the timing circuit 15 is used to convert picture/character information into an electric signal and the light sensor being a light receiving face uses a CdS or a photodiode as a bulk element, then the manufacture is facilitated and the cost is reduced. Further, since the liquid crystal shutter is manufactured easily by the technology put into practical use, the entire image sensor cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image sensor capable of converting an image into an electrical signal.

[Summary of the invention]

1. The image sensor of the present invention comprises a strip-shaped optical sensor that converts the intensity of light into an electrical value, and a liquid crystal shutter that opens and closes on a pixel-by-pixel basis on the light-receiving surface of the optical sensor. This allows large image sensors to be manufactured at low cost.

[Conventional technology]

A device that converts hard copy character/graphic patterns into electrical signals is CCD, which is composed of an IC circuit.
(Carge Coupled Device) Alternatively, a line sensor using a MOS transistor array is used.

By the way, an imaging device made of such a solid-state element is
As shown in FIG. 7, lines cl, c, ...CN of an imaging device consisting of a plurality of active elements are formed in a silicon wafer SiW by IC technology, and each Line c,,C,.

C3 .

[Problem that the invention seeks to solve]

By the way, such a line sensor has a speed of 8 dots/m, for example.
When configuring an A4 size line sensor with 125 m, it is necessary to form hundreds of 1-side moving circuit elements at intervals of 125 m, and there is a problem that the line sensor becomes expensive in terms of yield. .

Furthermore, each strip line CI, C7,...CN
For example, in order to give continuity to the joint part of
), by setting the dimension of the fort cell P on the end face of the line cl, c, . It is necessary to combine the pitch sentences of each fort cell so that they are uniform.

In addition, when 7 autocells P with the same pitch are formed, each line C+, C, .
, (1...) are concatenated at intervals of G so that the continuity is not impaired by electronic transmission of the output signal of the senna.

However, in any case, it is not easy to make the optical sensitivities of the connected strip-shaped IC circuit lines C, , c2, C, . . . uniform, and the manufacturing process becomes complicated. Therefore, there is a problem that the cost increases.

This invention was made to solve this problem, and provides an inexpensive image sensor by combining a general optical sensor and a liquid crystal shutter.

[Means for solving problems]

FIG. 1 is a partially cutaway perspective view showing the basic structure of the line sensor of the present invention, in which 1 and 2 are frame bodies provided with electrodes (not shown), and 3 is CdS.

Alternatively, it is an optical sensor having a light-to-electrical conversion function, such as a fort diode, which is divided into a plurality of optical sensor cells 3-1.3-2.3-3 as shown in the figure. Good too.

Further, numeral 4 indicates a liquid crystal shutter placed on the light receiving surface of the light sensor 3, and the liquid crystal shutter 4 is made of, for example, twisted nematic liquid crystal combined with a polarizing plate. Then, a plurality of shutter cells 4-K, 4- and +1, which open and close light at the center of the pixel by transparent electrodes,
It is formed by aggregating...

Note that 5 indicates a 1/lens system for focusing.

[Effect]

As shown in FIG. 2, when the image sensor of the present invention is mounted on a printed material 2 on which characters and figures to be input are printed via an optical system (not shown), lines x and h of the printed material 2 are
The reflected light R passes through the liquid crystal shutter 4 and is input to the optical sensor 3.

The liquid crystal shutter 4 is divided into, for example, shank cells 4-1.4-2.4-3...4-8 of about 8 pixels rtt, so for the electrode of each shank cell, When pulse signals are supplied in a time-division manner, the reflected light R first passes through the open shutter cell 4-1 and then impinges on the optical sensor 3-K, and then the shutter cell 4-2 is opened. Then, the reflected light R from this part is 'rf! After i passes, the brightness and darkness of the printed material is sequentially input to the optical sensor 3 in a time-division manner up to the shutter cell 4-8.

Therefore, the signal S obtained from the optical sensor 3 is on the line
The image signal S can be obtained by scanning the upper brightness and darkness.

〔Example〕

FIG. 3 shows an embodiment of the image sensor drive circuit of the present invention, in which numeral 10 is a liquid crystal driver that forms sequential pulses to drive the liquid crystal shutter 14, and numeral 11 is a liquid crystal driver that generates image quality obtained from the optical sensor 13. A data processing circuit 12 includes a plurality of amplifiers AI, A2, and A3.
. . . An output circuit with a built-in AN, and 15 a timing signal generation circuit.

The operation of the drive circuit will be described below with reference to the waveform diagram in FIG.

Now, the optical sensor 13 has N sensor cells 13-1.13-
2. It is divided into 13-3...13-6,
When the liquid crystal shank 14 in contact with each sensor is divided into n shutter cells, the liquid crystal shutter 14 is supplied with N sequential pulses PN as shown in FIG. A divided shutter opening/closing sequence pulse P is supplied.

Therefore, when the image sensor of the present invention is placed on the Xl line of the diagram ABCDEF and the order pulse PI-P6 and the shutter opening/closing order pulse Pn are supplied, each optical sensor cell 13-1, 13-2 .13-3
・・・・・・Signal SI as shown from 13-6
*S2, S:+... An image signal consisting of S6 is output.

Each of these signals is amplified by the amplifier A of the output circuit 12 and processed by the clock signals of the timing circuit 15, for example, the shift registers DO, D of the digital signal processing circuit 11.
I,...D6, and then the shift registers Do, DI are taken in by the timing signal PR.
, . . . are sequentially extracted from D6, and the data processing circuit 11 outputs the video signal Sxi corresponding to (1) life.

After this, as in the conventional case, when the printed material moves up Xl, one line, the video signal 58 (1°I) is generated by the same operation.
It outputs images and text information on printed matter and converts them into electrical signals.

As described above, the image sensor of the present invention can convert image and character information into electrical signals and output them using the control signal from the timing circuit 15 in the same way as conventional line sensors. Since semiconductor elements such as CdS or odd diodes can be used as bulk elements, manufacturing is easy and costs can be reduced.

Furthermore, since the liquid crystal shutter can be easily manufactured using technology that is already in practical use, the cost of the entire image sensor can be reduced.

The number N of optical sensor cells may be one in principle, but since the conversion speed will be reduced, it is preferable to divide the optical sensor cells into an appropriate number depending on the width of the line.

Further, the number of liquid crystal jack cells can be arbitrarily set depending on the resolution of the image reference character information to be collected.

FIGS. 5(a) and 5(b) show an effective embodiment when capturing a color image using the image sensor of the present invention.
A color filter 16 in which transparent plates made of primary colors RGB are arranged in order is sandwiched between them.

In this embodiment, the signal from the optical sensor when the liquid crystal shutter cell corresponding to the R transparent plate is opened is input to the R data signal processing circuit, and then the liquid crystal shutter cell corresponding to the G transparent plate is opened. The output signal of the light sensor when the sensor is opened is input to the G data signal processing circuit, and the signal when the B transparent liquid crystal shutter cell is opened is input to the B data processing circuit to produce 1947 minutes of color video. The signals s, s, , sB may be formed and read out synchronously.

In addition, in the case of FIG. 5(b), the optical sensor 17 is divided into three parts in the line direction, and three striped light-transmitting plates (
A color filter 18 provided with R, G, B) is brought into contact therewith.

The image sensor of this embodiment uses a liquid crystal display 14 in common to obtain video signals of three primary colors, and color-coded video signals SR, SG, and SR are directly output from the three-divided line of the optical sensor. can get.

Figure 6 is from wood [! ! 4 shows yet another example and ability, in which a plurality of combinations of the above-mentioned optical sensors 13 and 14 are arranged in parallel so that image information of a surface area can be collected.

In this case, the video signals output from each optical sensor 13, 13, . . . are output as parallel signals to terminals T+, T:.

It is also possible to take it out from T3 and input it directly to a liquid crystal display device or the like in the form of a battle line signal.

If an image sensor with such a surface area is used, it will be possible to capture moving images and the like in the same way as a normal solid-state image sensor.

〔Effect of the invention〕

As explained above, the image sensor of the present invention uses simple devices such as CdS and fort diodes as devices constituting the optical sensor. It is possible to use a bulk element with an i-structure, and by combining it with a liquid crystal shutter constructed using liquid crystal technology, there is an effect that a long, large-sized image sensor can be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the image sensor of the present invention, Fig. 2 is an explanatory diagram of the operation of the image sensor, Fig. 3 is a block diagram showing one embodiment of the image sensor drive circuit, and Fig. 4 is the waveform of the drive signal. 5(a) and 5(b) are schematic diagrams showing other embodiments of the present invention, FIG. 6 is a schematic diagram of an image sensor spread over a surface area, and FIG. 7 is a wafer of a conventional image sensor. FIG. 8 is an explanatory diagram of the line sensor, and FIGS. 9(a) and 9(b) are explanatory diagrams showing the structure of the end of the line sensor. In the figure, 1.2 is a frame body, 3 is an optical sensor, 4 is a liquid crystal shear,
In the evening, 5 indicates an optical lens. Figure 1 Image Konsakai deception ψ9 tome Figure 2 Sxi + 1-1'' - Dry book g L town number Rin Hanba Figure 4 Figure 7 - QO ＾ ＾
Bow, O

Claims (2)

[Claims] (1) An image sensor characterized by laminating at least a strip-shaped optical sensor and a liquid crystal shutter that can time-divisionally open and close light incident on the light-receiving surface of the optical sensor on a pixel-by-pixel basis. . (2) The image sensor according to claim (1), wherein the optical sensor is divided into N pieces.