JPH09247385A - Picture reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To preferentially execute processing of the picture signal of a necessary pixel by controlling a picture signal stored in a storing means to be read in order different from the pixel array in these plural line sensors. SOLUTION: Signals are outputted to output terminals V out 1 to 15 in the order of the pixel array inside the line sensors and this outputted signal is subjected to sample-and-hold processing by sample-and-hold circuits 40-41 to 40-15. Continually the signal is inputted to an A/D converter 41 by control signals ϕ SWW 1 to 15 to convert them into a digital signal. The output of the converter 41 is connected to a memory 42-a and disconnected from a memory 42-b by closing a switch 44-a and opening 44-b with control signals ϕodd and ϕ even. Then at the time of giving timing of writing data to the memory 42-a, the digital signal is stored in the memory 42-a. At this time, when a switch 45-a is opened and 45-b is closed, the photodetective signal of the memory 42-b is outputted to an output terminal D out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus mainly used for scanners, facsimiles and the like.

[0002]

2. Description of the Related Art As one of conventional image reading apparatuses, a contact type multi-chip image sensor including a light source, a short focus image forming element array and a plurality of line sensors is known. FIG. 20 is an external perspective view of such a contact type multi-chip image sensor, and FIG. 21 is a sectional view thereof.
LED board 21 provided in the frame 200 as shown
The emitted light 212 of the LED 211 mounted on the mirror 0 is reflected by the original surface 220 of the transparent glass plate 201 fixed to the upper part of the frame 200, and the reflected light 213 is reflected by the optical system 209.
Accordingly, an image is formed on the sensor array 1 provided on the substrate 19 correspondingly. Here, for example, the product name "SELHOC lens array" is used for the optical system.
A short focus imaging element array such as (manufactured by Nippon Sheet Glass Co., Ltd.) is used.

As shown in FIG. 22, the sensor array 1 is formed by arranging a plurality of line sensors 2-1, 2-2, ..., 2-15 on the substrate 19 in a straight line and is covered with a protective film 206. There is. In the contact type multi-chip image sensor, in principle, the reflected light from the original is imaged on the sensor array in the same size and read, so that the length of the sensor array 1 is required to be the width of the original to be read. Therefore, the required length of the sensor array 1 changes depending on the size of the document to be read, and the number of line sensors forming the sensor array 1 also changes. As an example, considering the case of reading an A3 size document, the length of one line sensor is 20 m.
If m, it is sufficient to configure the sensor array with 15 line sensors.

The substrate 19 is supported by a bottom plate 205 engaged with the frame 200 and connected to the flexible substrate 203 via flexible wiring 208. Further, a connector 202 for inputting / outputting a power supply, a control signal, etc. is provided on the flexible board 203, and the flexible board 203 is attached to the frame 200 by screws 207.

Next, the operation of the contact type multi-chip image sensor will be described with reference to the timing charts of FIGS. 23 and 24 showing the wiring on the substrate 19. A plurality of line sensors 2-1 and 2-2 arranged in a straight line on the substrate 19
The operation of 2-15 is started by the start pulse φSP, and the shift register 36-1 starts operating. Here, assuming that the number of light receiving elements arranged in each line sensor is 316, the shift register 36-1 which has started the operation
Are sequential switches 32-1-1, 32-1-2, ..., 32
-1-316 outputs a signal for conducting, and the light receiving elements 31-1-1, 31-1-2, ..., 31-1-316
And outputs the signal stored in the output line 33-1. While the line sensor 2-1 is reading, the switch 3
5-1 is conductive by the control signal φSW1, and outputs the signal output to the output line 33-1 to the common output terminal Vout on the substrate 19 via the buffer amplifier 34-1.

The shift register 3 in the line sensor 2-1
The output signal φEND1 at the final stage of 6-1 is connected to the line sensor 2-2 by the wiring on the substrate 19 and becomes the start pulse φST2 of the line sensor 2-2. Then, when the signal reading of the line sensor 2-1 is completed, the reading is started from the line sensor 2-2, the shift register 36-2 starts operating similarly to the line sensor 2-1, and the sequential switch 32-2-1. , 32-2-2, ..., 3
2-2-316 is conducted, and the light receiving element 31-2-
The signals accumulated in 1, 31-2-2, ..., 31-2-316 are output to the output line 33-2. Line sensor 2-2
The switch 35-2 is turned on by the control signal φSW2 while the reading is performed, and the signal output to the output line 33-2 is output to the common output terminal Vout via the buffer amplifier 34-2. .

Similarly, the output signal φEND2 of the final stage of the shift register 36-2 in the line sensor 2-2 is connected to the line sensor 2-3 by wiring on the substrate 19, and the start of the line sensor 2-3 is started. When the pulse φST3 is reached, the line sensor 2-3 reads out the line sensor 2-
It continues to 2. In the following, line sensor 2-4
The signal from the line sensor 2-15 is also read out by the same procedure.

In this way, the plurality of line sensors 2-
Sensor array 1 composed of 1, 2-2, ..., 2-15
Functions as a single image sensor and has a common output terminal V
The signals of all the light receiving elements are sequentially output to out.

When the reading of one line is completed, the contact type multi-chip image sensor is shifted by one line in the sub-scanning direction (direction perpendicular to the direction in which a plurality of line sensors are arranged) and the next line is read. By repeating this operation for the size of the original, the image reading of the entire original is completed using the contact type multi-chip image sensor.

[0010]

However, in the above-described conventional example, since the signals of all the sensor chips are sequentially output to one output line, it takes time to obtain the signals for one line. In recent years, there is an increasing need to scan originals in a short time, but in order to increase the output speed with this configuration, it is necessary to improve the circuit configuration of the line sensor and the manufacturing process to improve performance, which increases costs. I was invited. Such an increase in the speed of analog signals has been a problem because there are many development factors in the peripheral portion, such as signal processing of the output signals, which also lengthens the development period.

Further, in the above-mentioned conventional example, the signal is read from the first light receiving element of the first line sensor, the signals of the second, third, ... Once in the order of reading all the light receiving elements of the second, third, ..., 15th line sensors.
The signal could only be read in the direction. For this reason, when it is desired to read a document in the reverse direction, the image sensor unit must be configured exclusively.
Further, when it is necessary to read signals in both the forward direction and the backward direction by one document reading device, a dedicated circuit is required.

In order to perform resolution conversion such as in the case of magnifying and outputting an original, an external dedicated circuit is still required, which increases the circuit scale and increases the cost.

Further, even when the signal processing is performed only for the signals obtained from some light receiving elements on the sensor array, the signals of all the light receiving elements must be read, which increases the capacity of the external memory and complicates the signal processing. I was doing.

[0014]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in an image reading apparatus according to claim 1, a plurality of line sensors for converting image pickup light into image signals are longitudinally arranged. In an image reading apparatus arranged in a direction, a driving unit that drives the plurality of line sensors, a storage unit that stores an image signal output from the line sensor driven by the driving unit, and a storage unit that stores the image signal. And a control means for controlling such that the image signals are read out in a different order from the pixel array of the plurality of line sensors.

Further, in the image reading device according to the fourteenth aspect, in the image reading device in which a plurality of line sensors for converting the imaging light into an image signal are arranged in the longitudinal direction, a driving means for driving the plurality of line sensors is provided. Storage means for storing the image signal output from the line sensor driven by the driving means, and control means for controlling the image signal stored in the storage means to be read at a resolution different from the stored resolution, It is characterized by having.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a diagram showing wiring of a substrate 39 on which a sensor array 1 which is a constituent element of a contact type multi-chip image sensor embodying the present invention is mounted. In the figure, the line sensors 2-1, 2-2, ..., 2-15 are exactly the same as those of the conventional example, but the wiring on the substrate 39 on which the sensor array 1 is mounted is shown in FIG.
Unlike the wiring on 9, each line sensor 2-1, 2-2,
The start pulse φSP for determining the timing to start the operation of the line sensor so that the line sensors 2-15 can be driven simultaneously and the clock pulse φCLK for determining the speed and timing of extracting the signal from the line sensor are all line sensors 2-1 and 2-2. -2, ..., 2-15 are directly input, and output lines corresponding to the number of line sensors are prepared so that the signal output of each line sensor can be taken out independently, and connected to the output terminals Vout1-15, respectively. are doing.

On the other hand, the output terminals Vout1 to Vout1 of the substrate 39 are
The digital signal output circuit 50 connected to 15 has the configuration shown in FIG. In the figure, sample and hold circuits 40-1, 40-2, ..., 40-15 are line sensors 2-1 and 2-2 output to output terminals Vout1-15.
The output signals of −2, ..., 2-15 are sampled and held by the control signal φSH, and the A / D converter 41 includes sample and hold circuits 40-1, 40-2,
The analog output signals of the line sensors 2-1, 2-2, ..., 2-15 sampled and held by 40-15 are converted into digital signals. In addition, the memory 42-
Reference numerals a and 42-b are for temporarily holding the signal converted into the digital signal by the A / D converter 41. Switches 43-1, 43-2, ..., 43-15 are sample and hold circuits 40-1, 40-2 ,.
Switches 44-a and 44-, which are switches for controlling the connection between the output signal of 15 and the A / D converter 41.
b is the output terminal of the A / D converter 41 and the memory 42-
a and 42-b are connected to the input / output terminals, and the switches 45-a and 45-b are the memory 42-
a, 42-b input / output terminals and digital signal output circuit 50
Is a switch for connecting to the digital output terminal Dout of. In addition, the control signal generation circuit 47 uses a read start pulse φSTR and a master clock pulse φMCL.
Each control signal necessary for the operation of the sensor array 1 and the digital signal output circuit 50 is generated from K, the pre-output circuit pixel setting signal PS, and the pre-output end pixel setting signal PE. The control signal φSH generated by the control signal generation circuit 47 is the sample and hold circuits 40-1, 40-2, ..., 40-1.
5, control signals φSWW1 to 15 are signals for giving timing to sample and hold the signal input to the signal 5, control signals φodd, signals for controlling opening and closing of the switches 43-1, 43-2, ..., 43-15. Signals for controlling opening and closing of the φeven switches 44-a, 44-b, 45-a, 45-b, control signals address-a, ad
address-b is an address signal for giving an address of digital data to be read and written to the memories 42-a and 42-b, and control signals WE-a and WE-b are the memory 4 respectively.
2-a, 42-b, write enable signal for giving timing to write data, control signal OE-a,
OE-b is an output enable signal for giving a timing of reading data from the memories 42-a and 42-b.

A document reading apparatus including the digital signal output circuit 50 has a reading start pulse φS shown in FIG.
The document reading operation is started by TR. In the present invention, the signal for one line of the original read by the sensor array 1 starts the original reading operation and is stored in the memory 42-a for the odd-numbered line and stored in the memory 42-b for the even-numbered line. It can be stored. When the signal of the odd-numbered line is being written to the memory 42-a, the signal already written one line before to the memory 42-b is output as a digital signal to the outside, and the signal of the even-numbered line is output to the memory 42-a. When writing to -b, the signal already written to the memory 42-a one line before is output as a digital signal to the outside. Therefore, the control signal φod generated by the read start pulse φSTR and the start pulse φSP
Based on d and φeven, it is determined whether the line currently being read by the image sensor is the odd-numbered line or the even-numbered line after starting the document reading operation, and the memory 42-
Input / output of a and 42-b is switched.

The operation of the sensor array 1 is common to both the odd-numbered line and the even-numbered line, and each line sensor 2-1 and 2-2 is driven by the start pulse φSP and the clock pulse φCLK supplied from the control signal generation circuit 50.
-2, ..., 2-15 independently start their operations simultaneously. First, each line sensor 2-1, 2-2, ..., 2
After outputting the signals already accumulated in all the light receiving elements within -15 and performing the preparatory operation to store the next line, the light receiving elements in each line sensor have already been output to the outside of the line sensor at a predetermined timing. Each line sensor 2-1, 2-2, ..., 2-15 starts outputting the stored signal and each line sensor 2-1, 2-2 ,.
Output stage switches 35-1, 35-2, ..., 3 in 15
5-15 is a control signal φSW generated in the line sensor
, ΦSW2, ..., φSW15 all conduct. First, the output terminals Vout1 to 15 on the substrate 39 are connected to the first light receiving elements of the line sensors 2-1, 2-2, ..., 2-15, that is, 1 and 3 on the sensor array 1, respectively.
The signal of the 17th, ..., 4425th light receiving element is output,
Then, the second light receiving element of each line sensor 2-1, 2-2, ..., 2-15, that is, 2, 3 on the sensor array 1.
18, ..., 4426th light receiving element signal, and further, third light receiving element, that is, 3,319 on the sensor array 1,
The signal of the light receiving element in each of the line sensors 2-1, 2-2, ..., 2-15, such as the signal of the 4427th light receiving element, is sequentially output to each output terminal Vout1-15, and finally, The signals of the 316th, 632nd, ..., 4740th light receiving elements are read out, and the signal readings of all the light receiving elements of all the line sensors are completed in the reading time for almost one chip.

The above digital signal output circuit 50
, 2-15 output the signals accumulated in the pixels by taking as an example the operation of the document reading apparatus including The previous period will be described with reference to FIG. 4, and the period during which a signal is output will be described with reference to the timing chart of FIG.

In FIG. 4, each line sensor 2-1, 2-2,
, 2-15 are input with a start pulse φSP and a clock pulse φCLK at predetermined timings that satisfy the operation conditions, and the memory 42 in the pre-output period from the start of the document reading operation to the output of the signal of the first pixel -A,
42-b shows the state of signal input / output. During this period, the signals already accumulated in all the light receiving elements in each line sensor 2-1, 2-2, ..., 2-15 are output, and the preparatory operation for accumulating the next line is performed. No signal is output to the outside of the line sensor. Therefore, the memory 42-a
Since no signal is written to or read from the write enable signal WE-a, output
The enable signal OE-a is fixed at the H level.
On the other hand, the memory 42-b has a write enable signal WE.
-B remains fixed at the H level, but the output enable signal OE-b falls and the memory 42
The signal can be read from -b.

During this pre-output period, only the signals of the pixel regions set in advance by the pre-output start pixel setting signal PS and the pre-output end pixel setting signal PE by the address signal address-b are in line with the pixel array on the sensor array 1. Output at a predetermined speed in order. The output speed of the digital signal here is arbitrary, but the start pulse φS
After P is input, each line sensor 2-1, 2-2, ...,
It is sufficient to set the maximum number of pixels desired to be output at the time of pre-output to a speed at which the output can be performed during the period until the signal of the first pixel 2-15 is output.

This pre-output signal is, for example, the pre-output start pixel setting signal PS on the memory 42-b in which the signal of the 159th photosensor of the 12th line sensor, that is, the 3635th photodetector on the sensor array 1 is held. The pre-output end pixel setting signal PE is used as an address and the 158th line sensor of the 15th line sensor, that is, 4 on the sensor array 1.
Memory 4 holding the signal of the 582nd light receiving element
By setting the address on 2-b, it is possible to take out the signals on the hatched lines shown in FIG. 6 separately before reading all the signals of one line, and it is possible to process the signals of this part prior to all the signals. is there.

Next, in the pre-output period, that is, in the respective line sensors 2-1, 2-2, ..., 2-15, the signals already accumulated in all the light receiving elements are output to accumulate the next line. When the period of performing the preparation operation is completed, the signal reading operation from each line sensor 2-1, 2-2, ..., 2-15 shown in FIG. 5 is started. Each line sensor 2-1
2-2, ..., 2-15 At the same time, signals are started to be output to the output terminals Vout1 to 15 in the order of the pixel arrangement inside the line sensor, and the output signals are sampled and held by the sample-hold circuit 40-.
1, 40-2, ..., 40-15 sample and hold all line sensors 2-1, 2-2, ..., 2-15 at the same timing by the control signal φSH, and subsequently control signals φSWW1, φSWW2. , ΦSWW15 sequentially opens and closes the switches 43-1, 43-2, ..., 43-15 one by one, and the line sensors 2-1 and 2-2 sampled and held one by one from the line sensor 2-1 in order. −
The output signals of 2, ..., 2-15 are input to the A / D converter 41 and converted into digital signals. In this way, when the sampling and A / D conversion of the signals of the first light receiving element of all the line sensors 2-1, 2-2, ... , ..., 2-15 are subjected to sampling and A / D conversion of the signal of the second light receiving element, and the same processing is sequentially performed for the signals of the third and subsequent light receiving elements.

The digital output of the A / D converter 41 is connected to the input / output terminal of the memory 42-a by controlling the switch 44-a to be closed and the switch 44-b to be opened by the control signals φodd and φeven. And memory 4
It is separated from the input / output terminal of 2-b. Memory 42-a
The output enable signal OE-a for giving the timing of reading data from is fixed to the H level. Then, a write enable signal WE-a that gives a timing for writing data to the memory 42-a, and an address corresponding to the position on the sensor array 1 of the light receiving element from which the sequentially transmitted signals are read are set to the memory 42-a.
These digital signals are stored in the memory 42-a by the address signal address-a for giving to a.

In this way, when the sensor array 1 reads the odd-numbered lines and writes them in the memory 42-a, the switch 4 is turned on by the control signals φodd and φeven.
Controlled to open 5-a and close 45-b,
The input / output terminal of the memory 42-b is the digital output terminal Dou
The input / output terminal of the memory 42-a is disconnected from the digital output terminal Dout. And the memory 42-
output enable signal OE-b given to b
Since it has fallen, data can be output from the input / output terminal of the memory 42-b.
Address signal addr corresponding to the arrangement order of the upper light receiving elements
The signals of all the light receiving elements on the sensor array 1 which are already read one line before by ess-b and stored in the memory 42-b are sequentially output to the digital output terminal Dout one by one as a digital heart.

Even when the even-numbered lines are read from the start of reading the original, the original reading apparatus according to the present invention operates in the same procedure, and the original is read one line before and stored in the memory 42-a. Pre-output start pixel setting signal PS, pre-output end pixel setting signal PE from the signals of all the light receiving elements, the signals of the light receiving elements included in the area set by the pre-output are output within the pre-output period, and the signals of all the light receiving elements are output. Is then output.

In this way, when the signals once stored in the memory are taken out as digital signals, the pre-output start pixel setting signal PS and the pre-output end pixel are set before the signals of all the light receiving elements are taken out in the order of arrangement of the light receiving elements on the sensor array. By pre-outputting and extracting only the signals of the light receiving elements corresponding to a part of the area set by the setting signal PE in the original, a part of the area is preceded by the signal processing of all the light receiving elements in advance. It is possible to perform different signal processing only for. For example, the color of the original may be detected by the preceding read signal, and the subsequent signal processing may be changed in accordance with this.

As described above, the wiring on the substrate on which the sensor array is mounted is changed, a plurality of line sensors forming the sensor array are driven independently at the same time, and the output signals are temporarily stored in the memory. By taking out to the outside at the time of reading a line, it becomes possible to read one sensor array in the reading time for one line sensor in the conventional reading method. Also, since it is read as a digital signal from the memory, it can be performed at a sufficiently high speed as compared with the case of reading an analog signal directly from the line sensor, and within the reading time for one line sensor required for writing a signal to the memory. Can be completed. Also, since it is possible to read from the memory multiple times, only the signals of the light receiving elements corresponding to a partial area of the document are pre-output before the signals of all the light receiving elements are taken out from the memory in the order of arrangement of the light receiving elements on the sensor array. It is possible to perform the signal processing for only a part of the area before performing the signal processing for all the light receiving elements in advance by taking out. In addition, it is not necessary to make any changes or improvements to the line sensor itself in order to obtain the above effects, and it is only necessary to change the wiring on the board that mounts the sensor array and add a digital signal output circuit. It is possible to realize a document reading device capable of various signal processing with a limited cost increase.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
It is a diagram showing a digital signal output circuit 52 in the embodiment of. In the figure, a control signal generation circuit 51 generates each control signal necessary for the operation of the sensor array 1 and the digital signal output circuit 52 from a read start pulse φSTR and a master clock pulse φMCLK, and a pre-output start pixel setting signal PS The configuration is the same as that of the first embodiment except that the pre-output end pixel setting signal PE is eliminated. Further, the sensor array 1 and the substrate 39 on which the sensor array 1 is mounted are also the same as those in the first embodiment.

The original reading device including the digital signal output circuit 52 starts the original reading operation by the reading start pulse φSTR shown in FIG. Taking an example of reading an odd-numbered line from the start of reading an original, the pre-output period, that is, each line sensor 2-
The operation of the document reading apparatus will be described with reference to the timing chart of FIG. 8 for a period before the signals 1, 2-2, ..., 2-15 output to the pixels are output.

In FIG. 17, each line sensor 2-1 and 2-
2, ..., 2-15, the start pulse φSP and the clock pulse φCLK are input at predetermined timings that satisfy the operating conditions, and the pre-output period from the start of reading one line to the output of the signal of the first pixel In memory 42
4A and 42-b show signal input / output states. During this period, each line sensor 2-1, 2-2, ..., 2-15
The signals already stored in all the light receiving elements are output therein, and the preparatory operation for storing the next line is performed, and the signal is not output to the outside of the line sensor. Therefore memory 4
Since neither signal writing nor signal reading is performed on 2-a, the write enable signal WE-a and the output enable signal OE-a are fixed to the H level. On the other hand, in the memory 42-b, the write enable signal WE-b remains fixed at the H level, but the output enable signal OE-b falls and the signal can be read from the memory 42-b. ing.

In this embodiment, the image signals of the two specific areas which are constant at all times are continuously output during this pre-output period. As shown in FIG. 8, one is 11 on the sensor array 1.
The light-receiving elements in the first half of the 12th line sensor to the first half of the 12th line sensor, that is, the 3319th to 3634th light-receiving elements on the sensor array 1, read the area. The light receiving elements of the second half to the first half of the 14th line sensor, that is, 39 on the sensor array 1
The 51st to 4266th light receiving elements are areas to be read, and the address signal address-b is the memory 42-b so that the signals can be taken out from the addresses on the memory 42-b in which the signals of the light receiving elements in these areas are stored. Given to.

FIG. 9 shows the sizes of A4, B4 and A3 originals and the plurality of line sensors 2-1 and 2-2 on the sensor array 1.
, 2-15 showing the positional relationship between them, and the hatched area in the figure is the area read by the signal output in the pre-output period, and covers the edges of the A4 and B4 originals, respectively. are doing.

FIG. 10 shows an example of signals output during the pre-output period when the first few lines have been read since the start of reading the original. Since the upper end of the document is usually a white background of the document in which nothing is written, the document size can be detected from the pre-output signal at the time of the first few lines when reading this part. For example, in the case of an A4 original, FIG.
As shown in (a), the first region of the pre-output, that is, the first half of the eleventh line sensor on the sensor array 1
In the original area read by the light receiving element in the first half of the second line sensor, the pre-output signal changes from a white level to a black level at a certain light receiving element, and the second area of pre-output, that is, on the sensor array 1. The pre-output signal is always constant at the black level in the original area read by the light receiving elements in the second half of the thirteenth line sensor to the first half of the fourteenth line sensor. Similarly, in the case of a B4 original, the pre-output signal is always constant at the white level in the first pre-output area as shown in FIG.
In the area, the white level changes to the black level with a certain light receiving element as a boundary. Similarly, in the case of an A3 original, FIG.
As in (c), the white level is always constant in both the first and second areas of pre-output.

In this way, the document size can be detected from the pre-output signal at the time of reading the first several lines after starting the document reading. Therefore, the original size is judged by the pre-output signal which is output before reading the signals of all the light receiving elements on the sensor array 1 at the beginning of reading the original, and the reading of the remaining lines is changed and It is also possible to optimize the signal processing for the signal.

In this case, the pre-output is not used after the first few lines of the original, but the pre-output may be always output, or the number of lines read after starting the original reading operation is counted. The pre-output signal may not be output in an unnecessary area.

Further, the signal writing and signal reading operations of the memories 42-a and 42-b in the all pixel output period after the pre-output period are the same as those in the first embodiment. It does not affect the normal operation such that the document reading time for a line becomes long and the signal output timing for all pixels is deviated.

(Third Embodiment) This embodiment is still another form of the digital signal output circuit connected to the substrate 39 of FIG.

The digital signal output circuit 50 connected to the output terminals Vout1 to 15 of the substrate 39 has the structure shown in FIG. In the figure, the sample-and-hold circuits 40-1, 40-2, ..., 40-15 are output terminals Vou.
Line sensors 2-1, 2-2 output at t1 to 15,
The output signal of 2-15 is sampled and held by the control signal .phi.SH, and the A / D converter 41 includes sample and hold circuits 40-1, 40-2 ,.
Each line sensor 2 sampled and held by 15
-1, 2-2, ..., 2-15 analog output signals are converted into digital signals. In addition, the memories 42-a and 42-b
Is for temporarily holding the signal converted into a digital signal by the A / D converter 41. Switches 43-1, 43-2, ..., 43-15 are switches for controlling the connection between the output signals of the sample and hold circuits 40-1, 40-2, ..., 40-15 and the A / D converter 41. The switches 43-a and 43-b are switches for connecting the output terminal of the A / D converter 41 and the input / output terminals of the memories 42-a and 42-b, and switches 44-a and 44-b. Is a switch for connecting the input / output terminals of the memories 42-a and 42-b and the digital output terminal Dout of the digital signal output circuit 50. Further, the control signal generation circuit 47 causes the reading start pulse φST
Each control signal required for the operation of the sensor array 1 and the digital signal output circuit 50 is generated from R, the master clock pulse φMCLK, and the read mode setting signal RMODE. Control signal φ generated by control signal generation circuit 47
SH is a sample and hold circuit 40-1, 40-2,
.., control signal φSWW1 for giving timing for sampling and holding the signal input to 40-15
˜15 are switches 43-1, 43-2, ..., 43-15
For controlling opening and closing of the control signals φodd and φe
ven is a switch 44-a, 44-b, 45-a, 45
-B signal for controlling opening / closing, control signal addre
ss-a and address-b are memory 42-
a, 42-b, address signals for giving addresses of digital data to be read and written, control signals WE-a, WE
-B is a write enable signal for giving a timing of writing data to the memories 42-a and 42-b, and control signals OE-a and OE-b give a timing of reading data from the memories 42-a and 42-b. Is an output enable signal.

The contact type multi-chip image sensor is shown in FIG.
The document reading operation is started by the reading start pulse φSTR shown in FIG.
, 2-15 also start operation by the start pulse φSP and the clock pulse / CLK supplied from the control signal generation circuit 50. Each line sensor 2-1, 2-2, ...,
Each of the line sensors 2-15 starts its operation and starts outputting the image signal stored in the light receiving element in each line sensor.
-1, 2-2, ..., Output stage switch 35 in 2-15
-1, 35-2, ..., 35-15 are control signals φSW1, φSW2, ..., φSW15 generated in the line sensor.
Thus, the line sensors 2-1, 2-2, ..., 2-15 are all in conduction while outputting an image signal. Then, first to the output terminals Vout1 to 15 on the substrate 39, the first light receiving elements of the respective line sensors 2-1, 2-2, ..., 2-15, that is, 1,317 on the sensor array 1, respectively.
The signal of the 4425th light receiving element is output. Then, the second light receiving element of each of the line sensors 2-1, 2-2, ..., 2-15, that is, 2, 31 on the sensor array 1.
A signal from the 8th, 4426th light receiving element is output, and the third light receiving element, that is, 3 on the sensor array 1 is output.
The signals of the light receiving elements in the line sensors 2-1, 2-2, ..., 2-15, such as the signals of the 319th, ..., 4427th light receiving elements, are sequentially output to the output terminals Vout1-15. Finally, the signals of the 316th, 632, ..., 4740th light receiving elements are read, and the signal reading of all the light receiving elements of all the line sensors is completed in the reading time for almost one chip.

While the signals of all the line sensors are being read, the operation of the digital signal output circuit shown in FIG. 11 is started to be read, and the odd-numbered line is read in FIG. 13, the even-numbered line. The time of reading will be described with reference to the timing chart of FIG.

First, the output signals of the line sensors 2-1, 2-2, ..., 2-15 output to Vout 1-15 are sample and hold circuits 40-1, 40-2 ,.
5, all the line sensors 2-1, 2-2, ..., 2-15 are simultaneously sampled and held by the control signal φSH shown in FIGS. 13 and 14, and then the control signals φSWW1, φ
SWW2, ..., Switch 43-1 by φSWW15,
43-2 are sequentially opened and closed one by one, and the line sensors 2-1 to 2-2, ..., 2-15 sampled and held one by one from the line sensor 2-1 in order. The output signal is input to the A / D converter 41 and converted into a digital signal. In this way, all line sensors 2-1 and 2-2
When the sampling and A / D conversion of the signal of the first light receiving element of −2, ..., 2-15 are completed, each line sensor 2-
The signals of the second light receiving elements 1, 2-2, ..., 2-15 are sampled and A / D converted, and the same processing is sequentially performed on the signals of the third and subsequent light receiving elements.

The digital signal thus obtained is temporarily stored in the memory 42-a or 42-b and then digitally output from the memory 42-a or 42-b while reading the next line. It is taken out through the terminal Dout. Which memory is used depends on whether the read line is an odd-numbered line or an even-numbered line after the original reading operation is started, and therefore, as shown in FIG. 12, the control signal φodd from the read start pulse φSTR and the start pulse φSP. φeven is generated, and the memories 42-a and 42-b are switched. Further, the direction of taking out the data from the memory is the read mode setting signal RM input to the control signal generating circuit 47 of FIG.
It is set by ODE. When RMODE = L, data is output in the same direction as the arrangement direction of the light receiving elements on the sensor array 1, and when RMODE = H, data is output in the opposite direction.

First, the read mode setting signal RMODE =
The case of L, that is, the case where signals are read in the same direction as the arrangement direction of the light receiving elements on the sensor array 1 will be described.

First, when reading odd-numbered lines, A
The digital output of the / D converter 41 is the control signal φod.
switch 44-a is closed by d and φeven,
-B is controlled to open so that the memory 42
It is connected to the input / output terminal of -a and separated from the input / output terminal of the memory 42-b. Also, an output for giving a timing for reading data from the memory 42-a.
The enable signal OE-a is fixed at the H level.
Then, the write enable signal WE-a for giving a timing for writing data to the memory 42-a, and the sensor array 1 of the light receiving elements from which the signals sequentially sent are read
These digital signals are stored in the memory 42-a by the address signal address-a for giving the address corresponding to the above position to the memory 42-a.

At this time, at the same time, control signals φodd and φev
It is controlled by en to open the switch 45-a and close the switch 45-b, the input / output terminal of the memory 42-b is connected to the digital output terminal Dout, and the input / output terminal of the memory 42-a is digital output. It is separated from the terminal Dout. An output enable signal OE-b for enabling data output from the memory 42-b and an address signal a for giving a signal for reading data to the memory 42-b in the order of arrangement of the light receiving elements on the sensor array 1.
With the address-b, the digital data already read one line before and stored in the memory 42-b is output from the memory 42-b in the same order as the arrangement of the light receiving elements on the sensor array 1.

Next, when reading the even-numbered lines, A
The digital output of the / D converter 41 is the control signal φod.
Switch 44-a is opened by d and φeven, and 44
-By controlling b to be closed, the memory 42-
It is connected to the input / output terminal of b and is disconnected from the input / output terminal of the memory 42-a. The output enable signal OE-b for giving the timing of reading the data from the memory 42-b is fixed to the H level. Then, a write enable signal WE-b that gives a timing for writing data to the memory 42-b, and an address corresponding to the position on the sensor array 1 of the light receiving element from which the sequentially transmitted signals are read are set to the memory 42-b. These digital signals are stored in the memory 42-b by the address signal address-b for giving to b.

At this time, at the same time, control signals φodd and φev
It is controlled by en to close the switch 45-a and open the switch 45-b, the input / output terminal of the memory 42-a is connected to the digital output terminal Dout, and the input / output terminal of the memory 42-b is digital output. It is separated from the terminal Dout. An address enable signal OE-a for enabling data output from the memory 42-a and an address signal a for giving a signal for reading data to the memory 42-a in the order of arrangement of the light receiving elements on the sensor array 1.
The digital data already read one line before and stored in the memory 42-a is output by the address-a from the memory 42-a in the order in which the light receiving elements on the sensor array 1 are arranged.

According to the above-described procedure, the signals of all the light receiving elements on the sensor array 1 stored in the memory 42-a or 42-b are read at the same time as the signals of all the line sensors are read at a timing deviated from the original reading. Output to the digital output terminal Dout.

Next, the read mode setting signal RMODE =
A case where the signal is read out at the time of H, that is, in the direction opposite to the arrangement direction of the light receiving elements on the sensor array 1 will be described.

In this reading mode, the writing of the digital output of the A / D converter 41 into the memories 42-a and 42-b is exactly the same as the above-mentioned reading in the forward direction. The address signal add is also applied to the output from the memories 42-a and 42-b to the digital output terminal Dout.
The control signals other than res-a and address-b are exactly the same as in the case of reading in the forward direction. Only the address signals address-a and address-b can take out the data on the sensor array 1 in the reverse order of the arrangement of the light receiving elements, and as shown in FIGS. In both readings, the data read as 4739, 4738, ..., 2, 1 from the 4740th pixel on the right end of the sensor array 1 is output to the digital output terminal Dout.

As described above, since the reading from the memory to the digital output terminal is digital data, the reading can be performed at a sufficiently high speed as compared with the case where the analog signal is directly read from the line sensor, which is equivalent to one line sensor in the conventional reading method. Since one sensor array can be read in the reading time, high-speed reading can be realized without any change or improvement in the line sensor itself. Further, the data can be taken out in either the forward direction or the backward direction by simply setting the address signals when reading from the memory in the reverse order. The image sensor unit is now available. Further, even when it is desired to read from both directions in one original reading device in the reading mode, it can be realized with almost no increase in cost only by setting the reading mode setting signal.

As described above, the wiring on the substrate of the contact type multi-chip image sensor is changed, all the same line sensors as in the prior art which compose the sensor array are driven at the same time, and the signal output independently taken out on the substrate is output. Even if the line sensor itself does not need to speed up the output, by switching with a switch, A / D converting and writing to the memory, and after the signals of all the light receiving elements are written into the memory, the signals are extracted at high speed as digital signals. It has become possible to speed up the signal output of the contact type multi-chip image sensor by using the conventional line sensor.

Further, the data once written in the memory can be read out in the same order as the arrangement of the light receiving elements on the sensor array or in the reverse order by changing only the way of giving the address signal, so that the same multi-chip is used. The image sensor made it possible to read from both directions.

(Fourth Embodiment) FIG. 17 is a diagram showing a digital signal output circuit 51 according to a fourth embodiment of the present invention. In the figure, the control signal generation circuit 48 includes a read start pulse φSTR, a master clock pulse φMCLK, and two read mode setting signals RM.
Third embodiment except that ODE1 and RMODE2 generate respective control signals necessary for the operation of the sensor array 1 and the digital signal output circuit 51, and two read mode setting signals are inputted. The configuration is similar to that of the above. Here, the reading mode setting signal RMO
DE1 has the same function as RMODE in the third embodiment, and when RMODE1 = L, signals are output in the order of arrangement of the light receiving elements on the sensor array 1,
When RMODE1 = H, signals are output in the reverse order of the arrangement of the light receiving elements on the sensor array 1. The reading mode setting signal RMODE2 is a signal for setting the resolution of the output signal in the main scanning direction. When RMODE2 = L, all signals of all light receiving elements on the sensor array 1 are output, and when RMODE2 = H, the sensor is output. The signal of the light receiving element on the array 1 is output every other pixel.

In the contact type multi-chip image sensor to which the digital signal output circuit 51 is connected as described above, the reading start pulse φSTR, the master clock pulse φMCLK, and the reading mode setting signals RMODE1 and RMODE2 are input to the control signal generating circuit 48. The reading operation is started, and each line sensor 2-1 and 2-
2, ..., 2-15 also start operation by the start pulse φSP and the clock pulse φCLK supplied from the control signal generating circuit 51. The operation of storing the signals of all the light receiving elements of each line sensor 2-1, 2-2, ..., 2-15 on the sensor array 1 in the memory 42-a or 42-b is the same as in the third embodiment. it can.

The operation of outputting data from the memory 42-a or 42-b to the digital output terminal Dout is performed by reading mode setting signals RMODE1 = L, RMODE2 = H,
That is, the operation for reading the odd-numbered lines when the mode for reading in the forward direction and outputting at half the resolution is set will be described as an example with reference to the timing chart shown in FIG.

When reading odd-numbered lines by the same operation as that of the third embodiment, each line sensor 2-1, 2-2, ..., 2 on the sensor array 1 is stored in the memory 42-a.
The signals of all the light receiving elements of -15 are stored.

At this time, at the same time, control signals φodd and φev
It is controlled by en to open 45-a and close 45-b, the input / output terminal of the memory 42-b is connected to the digital output terminal Dout, and the input / output terminal of the memory 42-a is a digital output terminal. Separated from Dout. In order to provide the memory 42-b with an output enable signal OE-b for enabling data output from the memory 42-b and a signal for reading data every other pixel in the order of arrangement of the light receiving elements on the sensor array 1. In response to the address signal address-b of, the digital data stored in the memory 42-b which has been read one line before is output from the memory 42-b. Address signal add
Less-b is 1, 3, 5, ..., 4 on the sensor array 1.
Only the address on the memory 42-b in which the signals of the 737, 4739-th light receiving element are stored are selected, and 2, 4,
The signals of the 6th, 4738, and 4740th light receiving elements are not read. Since the number of data output from the digital output terminal Dout is half the number of data input to the memories 42-a and 42-b, the frequency of the output signal from the digital output terminal Dout is the memory 42- a, 4
It may be 1/2 of writing to 2-b.

As described above, when RMODE2 = H, only half of the light receiving elements on the sensor array 1 are used. Therefore, as shown in FIG.
Data may be written to a and 42-b only for half the pixels. In this method, the output signals of the line sensors 2-1, 2-2, ..., 2-15 output to Vout 1-15 are sample-hold circuits 40-1, 40-2,
, 40-15 simultaneously sample and hold all line sensors 2-1, 2-2, ..., 2-15 by control signal φSH, and subsequently control signals φSWW1, φSWW
2, ..., φSWW15 switches 43-1 and 43-
, ..., 43-15 are sequentially opened and closed one by one, and are sequentially input from the line sensor 2-1 to the A / D converter 41 to be converted into digital signals.

At this time, the control signal φSH samples and holds the output signals of the line sensors 2-1, 2-2, ..., 2-15 every other pixel, and the sampled and held signals are also stored in the line sensor 2. -1, 2-2, ..., 2-15
Of the output signal of 2 pixels are sequentially A / D converted.

At this time, the digital output terminal of the A / D converter 41 is controlled by the control signals .phi.odd and .phi.even so that the switch 44-a is closed and the switch 44-b is opened. It is connected to the terminal and is disconnected from the input / output terminal of the memory 42-b. The output enable signal OE-a for giving the timing of reading data from the memory 42-a is fixed to the H level. Then, a write enable signal W which gives a timing for writing data in the memory 42-a
E-a, and an address signal addre for giving to the memory 42-a an address corresponding to the position on the sensor array 1 of the light-receiving element from which the signal sequentially sent is read.
These digital signals are stored in the memory 42-by the ss-a.
It is stored in a.

Then, each line sensor 2-1, 2-2,
After writing the signal of the first light receiving element of 2-15, this time, again, the line sensors 2-1, 2-2, ..., 2-
The signal of the third light receiving element is written into the memory 42-a over a time period corresponding to two output signals of 15 pixels.

With the above procedure, each line sensor 2-1 and
2-2, ..., 2-15, 5, 7, 9, ..., 313, 31
The signal from the fifth light receiving element is sent to the line sensors 2-1 and 2-
2, ..., 2-15 output signals are sequentially A / D-converted over a time period corresponding to two pixels, so that only the signal output from the memory 42-a to the digital output terminal Dout is sufficiently stored in the memory 42-a. You can write in a long time.

On the other hand, the input / output terminal of the memory 42-b is controlled by the control signals φodd and φeven so that the switch 45-a is opened and the switch 45-b is closed, and is connected to the digital output terminal Dout. And the memory 42-
output enable signal OE-b for enabling data output from b and an address signal addres for giving a signal for reading data every other pixel on the sensor array 1 in the arrangement order of the light receiving elements to the memory 42-b.
By sb, the memory 4 already read one line before
2-b stores the digital data stored in the memory 42-
Output from b.

As described above, if only the signals to be written in the memories 42-a and 42-b are read from the memories 42-a and 42-b, the input / output and A / D conversion of the memories 42-a and 42-b can be performed. You can spend enough time. If there is no problem in reading analog signals from the line sensors on the sensor array 1, inputting / outputting the memories 42-a and 42-b, and A / D conversion, it is twice as much as reading signals from all light receiving elements. Since it becomes possible to read at the speed of, it is effective when it is desired to read at high speed even if the resolution is lowered.

As described above, the resolution conversion of the light receiving element on the sensor array is possible by outputting the data written in the memory every other pixel by controlling the address signal to the memory and outputting from the sensor array. By controlling the sampling and holding of the analog signal to be generated and the connection to the input terminal of the A / D converter, it becomes possible to read out at a higher speed when the resolution is reduced.

[0069]

As described above, in the image reading device according to the first aspect of the present invention, in the image reading device in which a plurality of line sensors for converting imaging light into an image signal are arranged in the longitudinal direction, the plurality of line sensors are arranged. Driving means for driving the line sensor, storage means for storing the image signal output from the line sensor driven by the driving means, and pixel array of the plurality of line sensors for storing the image signal stored in the storage means And a control unit that controls the reading so that the reading is performed in a different order. With such a configuration, by reading out in a different order from the pixel array of the line sensor, it becomes possible to perform the processing on the image signal of the necessary pixel first.

Further, in the image reading device according to the fourteenth aspect, in the image reading device in which a plurality of line sensors for converting the imaging light into an image signal are arranged in the longitudinal direction, a driving means for driving the plurality of line sensors is provided. Storage means for storing the image signal output from the line sensor driven by the driving means, and control means for controlling the image signal stored in the storage means to be read at a resolution different from the stored resolution, It has a structure having. With this configuration, it is possible to easily obtain an image signal with a required resolution.

[Brief description of drawings]

FIG. 1 is a diagram showing a connection of main wirings related to signal output inside a line sensor which constitutes a sensor array and a substrate on which the sensor array is mounted in the first to fourth embodiments of the present invention. .

FIG. 2 is a diagram showing a configuration of a digital signal output circuit according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a timing relationship between a read start pulse φSTR and another control signal in the first and second embodiments of the present invention.

FIG. 4 is a diagram for explaining the timing of the input / output operation of the memory during the pre-output period at the time of reading the odd-numbered line in the first embodiment of the present invention.

FIG. 5 is a diagram for explaining input / output of a memory and operation timing of an image sensor during an all-pixel output period when reading an odd-numbered line in the first embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a range of an original read by a signal output during a pre-output period and a layout of a plurality of line sensors in a sensor array according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a digital signal output circuit according to a second embodiment of the present invention.

FIG. 8 is a diagram for explaining the timing of the memory input / output operation during the pre-output period when reading odd-numbered lines in the second embodiment of the present invention.

FIG. 9 is a diagram showing a relationship between a range of a document read by a signal output during a pre-output period, an arrangement of a plurality of line sensors in a sensor array, and each document size in the second embodiment of the invention. .

FIG. 10 is a diagram showing a relationship between respective document sizes and signals output during a pre-output period in the second embodiment of the present invention.

FIG. 11 is a diagram showing a configuration of a digital signal output circuit according to a third embodiment of the present invention.

FIG. 12 is a diagram for explaining a timing relationship between a read start pulse φSTR and another control signal in the third embodiment of the invention.

FIG. 13 is a diagram for explaining the operation timing of the image sensor including the input / output of the memory when reading the odd-numbered lines in the third embodiment of the invention.

FIG. 14 is a diagram for explaining the timing of the operation of the image sensor including the input / output of the memory when reading the even-numbered lines in the third embodiment of the invention.

FIG. 15 is a diagram for explaining the input / output timing of the memory when reading odd lines in the reverse read mode in the third embodiment of the present invention.

FIG. 16 is a diagram for explaining the input / output timing of the memory when reading an even line in the reverse read mode in the third embodiment of the present invention.

FIG. 17 is a diagram showing a configuration of a digital signal output circuit according to a fourth embodiment of the present invention.

FIG. 18 is a diagram for explaining a timing when outputting with a resolution of ½ of the light receiving element of the sensor array in the fourth embodiment of the invention.

FIG. 19 is a diagram for explaining a timing when inputting / outputting data to / from a memory with a resolution of ½ of the light receiving element of the sensor array in the fourth embodiment of the invention.

FIG. 20 is a view showing the outer shape of a conventional contact-type multi-chip image sensor for reading an original.

FIG. 21 is a view showing a cross section of a conventional contact-type multi-chip image sensor for reading a document.

FIG. 22 is a diagram showing an outer shape of a substrate on which a sensor array of a contact type multi-chip image sensor for reading a document of the related art is mounted.

FIG. 23 is a diagram showing a connection between the inside of a line sensor forming a conventional sensor array and main wirings related to signal output on a substrate on which the sensor array is mounted.

FIG. 24 is a diagram showing a timing for showing a conventional document reading procedure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 sensor array 2 line sensor 19,39 sensor substrate 31 light receiving element 34 buffer amplifier 35 switch 36 shift register 40 sample and hold circuit 41 A / D converter 42 memory 47, 48, 51 control signal generation circuit

Claims (19)

[Claims] 1. An image reading apparatus in which a plurality of line sensors for converting imaging light into image signals are arranged in a longitudinal direction, a driving unit driving the plurality of line sensors, and the line sensor driven by the driving unit. A storage unit that stores the image signal output from the storage unit; and a control unit that controls the image signals stored in the storage unit to be read in a different order from the pixel array of the plurality of line sensors. Image reading device. 2. The image reading device according to claim 1, wherein the driving unit drives the plurality of line sensors simultaneously. 3. The image reading apparatus according to claim 1, further comprising a plurality of holding units that temporarily hold the image signals of the plurality of line sensors. 4. The image reading device according to claim 1, further comprising an A / D conversion unit that converts the image signals of the plurality of line sensors into digital signals. 5. The storage means according to claim 1, wherein the storage means includes first and second storage means for storing image signals of odd-numbered pixels and even-numbered pixels of the plurality of line sensors, respectively. An image reading apparatus characterized by: 6. The image reading apparatus according to claim 1, wherein the control unit performs control so that reading is performed in a reverse order to a pixel array order of the line sensor. 7. The image reading apparatus according to claim 1, wherein the control unit controls the storage unit to read out image signals of predetermined pixels before reading out image signals of all pixels. 8. The image reading apparatus according to claim 1, wherein the control unit controls the image signal of the predetermined pixel stored in the storage unit to be read a plurality of times. 9. The image reading device according to claim 7, wherein the control unit detects the state of the subject based on an image signal of a predetermined pixel read from the storage unit. 10. The image reading device according to claim 9, wherein the control unit detects a size of a subject. 11. The image reading device according to claim 9, wherein the control unit detects a shape of a subject. 12. The image reading apparatus according to claim 9, wherein the control unit detects a color of a subject. 13. The image reading apparatus according to claim 9, wherein the control unit controls the output of the image signal according to the detected state of the subject. 14. An image reading apparatus in which a plurality of line sensors for converting imaging light into an image signal are arranged in a longitudinal direction, a driving unit driving the plurality of line sensors, and the line sensor driven by the driving unit. An image reading apparatus comprising: a storage unit that stores the image signal output from the storage unit; and a control unit that controls the image signal stored in the storage unit to be read at a resolution different from the stored resolution. 15. The image reading apparatus according to claim 14, wherein the driving unit drives the plurality of line sensors simultaneously. 16. The image reading apparatus according to claim 14, further comprising a plurality of holding units that temporarily hold the image signals of the plurality of line sensors. 17. The image reading apparatus according to claim 14, further comprising an A / D conversion unit that converts the image signals of the plurality of line sensors into digital signals. 18. An image according to claim 14, wherein said storage means comprises first and second storage means for respectively storing image signals of odd pixels and even pixels of said line sensor. Reader. 19. The image reading apparatus according to claim 14, wherein the control unit changes the resolution by thinning out and reading the image signals stored in the storage unit.