JPS586662A - Photosensor and processing method for signal information of photosensor - Google Patents

Abstract

PURPOSE:To increase the reading rate of a normal signal by providing a couple of photosensor arrays for a common wiring group constituted on an insulating substrate, obtaining two signals from one point on an original, and then comparing those signals with ach other. CONSTITUTION:For a common side wiring group 4 constituted on an insulating substrate, a couple of photosensor arrays 1 and 2 are formed at the same time so that they have exactly the same characteristics. The photosensor arrays 1 and 2 are provided with individual side wiring groups 6 and 7. An optical system 3 is arranged in such a way that light with the same quantity strikes the photosensor arrays 1 and 2. The common side wiring group 4 and individual side wiring groups 6 and 7 are switched simultaneously by respective driving circuits 5, 8 and 9. Sample holding circuits 10 and 11 input the same information from the photosensor arrays. A comparator compares the signals of the circuits 10 and 11 with each other and permits an analog multiplexer 13 to select one of two pieces of information with a higher or lower level. Consequently, a normal signal is outputted without reference to a fault of the photosensors.

Description

[Detailed Description of the Invention] The present invention is intended for use in facsimile, etc.
The contact type image line sensor KfQl corresponds dimensionally one-to-one with the original and reads the image.

In recent years, there has been a rush to develop contact type image line sensors for the purpose of downsizing and lowering the quality of facsimiles, etc., but for example, when sending a document of A4 size, the length of the licensor is 25 cs @ 97, and if the sensor film is integrally formed on such a large sensor, the defective product rate will be considerably higher than in the case of a short sensor due to the occurrence of V-V defects due to pinholes, scratches, etc. on the sensor film. As a countermeasure to this problem, there is a method of connecting several short sensors of good quality to form a long sensor, but integrated 5! It is more advantageous in terms of economy and labor saving to directly make a long sensor using the method.

The present invention was made in view of the above circumstances, and by simultaneously reading information from one point on a document using a pair of sensor elements and comparing the two signals, it increases the reading rate of normal signals. The present invention provides a highly reliable contact type image sensor.

According to the present invention, a pair of optical sensor arrays are connected symmetrically to a common wiring group configured on an insulating substrate, and each pair of optical sensor arrays transmits light emitted from the same point on the object to be measured. An optical sensor is obtained, which includes an optical system that guides the information, and a drive circuit that simultaneously switches the paired optical sensors and simultaneously outputs two reading signals from the same information source.

Furthermore, according to the present invention, a pair of signals outputted from a drive circuit are sampled and held by a pair of sample and hold circuits whose timing is determined by a control pulse outputted from the drive circuit, respectively, using the above-mentioned optical sensor, Next, the signals sampled and held by the comparator are compared in magnitude, and the output of the comparator is used as a selection switch for the analog multiplexer, and the higher or lower signal level of the two signals is selectively read and output as residual information. A method for processing signal information of an optical sensor is obtained.

Hereinafter, the configuration and embodiments of the present invention will be described in detail using the drawings.

#I1 is a product diagram showing the configuration of the present invention. In the figure, 1.2 is a photosensor array that may contain defects that were formed at the same time to have exactly the same characteristics, and 3 is a photosensor array that is in a pair and emits light with the same amount of light. The optical system is configured as follows, 4 and 5 are a common side wiring group and a common side drive circuit, respectively, 6 and 7 are individual side wiring groups for the optical sensor arrays A and B, respectively, and 8.9 is an individual side drive circuit. . These 5, 8, and 9 drive circuits consist of shift registers, analog switch arrays, etc.
It functions to simultaneously switch a pair of optical sensors that receive the same information. 10.11 is a sample hold circuit that holds two signals, and the timing of sampling is set at the point when the influence of overprinting of the signal due to switching has been reduced to a certain extent, and is controlled by the above-mentioned drive circuit.

12 is a comparator, which outputs two states depending on the magnitude of the two signals. 13 is an analog multiplexer, which selects two f depending on the state of the comparator.
It works by selecting either the higher level side or the lower level side of the IJt range signals and converting them into one level cutting signal.

Next, the operation will be explained in detail with reference to an embodiment of the present invention shown in FIGS. 12(a) and 3(b) and FIG. In FIG. 2(b), 14 is an LgD array, 15 is a transmission document, 16 is a glass substrate, and 17 is an island in the common wiring group and is a transparent #Jw pole.

#I2 As shown in Figure (b), first, a 1 m array irradiates light onto the surface of the transmission document. The light reflected on the document surface enters the optical system and is introduced so as to strike perpendicularly to the light-receiving surfaces of a pair of photosensors connected symmetrically to the common wiring group. Optical fibers are suitable for such purposes because they do not leak light and can freely change the optical path. Further, the above object can also be achieved by using a lens system and a half mirror as the optical system.

In this case, the pair of optical sensors are An shown in FIG. 2(a).

Compatible with h, Anew, and Bn+t. This An,
The Bn equal pairs of optical sensors are simultaneously switched by a common side drive circuit and an individual side drive circuit. Here, the common side and individual side have the same meanings as in the case of a conventional single photosensor array, and the common side of the present invention means that the common side in the case of a single photosensor array is made common for two arrays. It is something. Therefore, in the drive circuit of the present invention, the number of analog switch arrays on the individual side increases by only one set compared to the conventional optical sensor array. Furthermore, if the common side is integrated with an IC, it is possible to combine the switches on the common side and use one common electrode on each individual side. The complexity that arises and the increase in the number of fences is not instantaneous.

Next, the two switched signals are each held in a sample and hold circuit. In general, signals that have been switched or switched often have oversheets such as spike noises due to their capacitance.To ensure subsequent signal processing, samples should be taken when the oversheets have become relatively small. 1, this timing is controlled by the drive circuit. Specifically, switch the optical sensor! (after checking)
The drive circuit runs the sample and hold circuit after a predetermined delay time! The above objectives are achieved by

After ilk, the sampled and held signals are compared by a comparator. This comparator is a so-called operational amplifier, and the output voltage changes between two states depending on the magnitude of the input signal. This is used as a selection signal, and the analog multiplexer outputs either the higher potential or the lower potential of the two signals sampled and held.

The feature of this signal processing system is that if it is possible to predict in advance that the signal potential will be at a low or high level due to a defect occurring in the optical sensor, it selects the level opposite to the defect level. By setting the analog multiplexer, a normal output can be obtained unless both of the paired optical sensors are abnormal.

An example of signal processing will be explained using FIG. 3. In this example, as an extreme case, go to A1 of the optical sensor array A. 1
Of the optical sensors 6 of 01vJ, 3g of bird AyA* is defective and always outputs a low level output, and B of optical sensor array B,
~B. B4. out of 010 optical sensors. H, B? Consider a situation in which fi- has a similar defect. At this time, if the analog multiplexer is set so that a high-level signal passes through, the defective optical sensor pair overlaps, and normal signals can be read except for the portion B7.

Even when the optical sensor pair is normal, the one with the higher level is selected, but in this case, a normal 4s signal is output regardless of which one is selected. According to this method, if the defect occurrence probability for each bit in a single optical sensor array is P, then the equivalent defect occurrence rate w1 for each bit is P, and even if there are many defects, The new optical sensor can be used as long as it does not have the 81fJ41 relationship, which is resistant to defects, improving quality and reliability at the same time.

In the above explanation, the level of bias I due to the occurrence of defects is
) is unidirectional and that there is no correlation between the occurrence of defects in paired sensors. If there are pinholes or holes in the membrane, the electrodes will often be short-circuited or the resistance value will decrease dramatically. If there is the above defect in the shape sensor,
The electrodes are often open or the resistance value is larger than other normal elements, which satisfies the above assumption.

Further, the paired optical sensor arrays are separated by a common wiring group and are separated by a distance. Therefore, the correlation between the occurrence of defects during sensor film formation is small, and this also satisfies the above assumption.

As described above, according to the method of the present invention, a long and high-density optical sensor that is more reliable than the conventional one can be produced! It can be obtained easily and with high yield, and is useful for one-dimensional line sensors such as facsimiles.

Brief Explanation of the Figures [Figure 1 is a block diagram showing the configuration of the present invention, Figure 2 (a) is a partially cutaway plan view of one embodiment, Figure 2 (b)
is a front view of the same embodiment, and FIG. 3 is a diagram for explaining one embodiment of signal processing.

l, 2... Optical sensor array, 3... Optical system, 4...
・Common side part m group, 5... common side part lI! h circuit, 6.
7... Individual side wiring group, 8, 9... Individual side drive circuit,
30.11... Sample hold circuit, 12... Comparator, 13... Analog multiplexer, 14
...Old array, ]5... Transmission manuscript, 16...
Glass substrate, 17...Transparent electrode Fig. 2 3 (a) (b) v, Fig. 3 normal SJ-signal optical sensor array A AI A2 A3A4 As A6 AT
As Aq At.

Optical sensor array B B+ Bz Ba B4 85 86 B7
Ba Bq B+.

Yoshiuri, 1st Soi Kichigo

Claims (1)

[Claims] 1. Paired evening light sensor arrays are connected symmetrically to a common IPO configured on an insulating substrate, and light emitted from the same point on the object to be measured is paired. An optical sensor comprising an optical system that guides the optical sensor to the optical sensor, and a drive circuit that simultaneously switches the paired optical sensors and simultaneously outputs two read signals from the same information source. 2. Using the upper da optical sensor, a pair of signals output from the drive circuit is sampled and held by a pair of sample and hold circuits whose timing is determined by the control pulse output from the drive circuit, and then The signals sampled and held by the comparator are compared in magnitude, and the output of the comparator is used as the selection switch of the analog multiplexer, and the higher or lower signal level of the two signals is selectively read and output as information. A signal information processing method for an optical sensor, characterized in that: