JPS6169257A - Image reading device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image reading device that scans an original image, such as a facsimile or scanner device, and particularly includes a plurality of solid-state image sensors such as COD. .

Conventional configuration and its problems When scanning an original image and reading original image information using a solid-state image sensor such as COD, for the purpose of securing a wide readable area or increasing the resolution of image information, An image reading device is configured in which a plurality of solid-state image sensors are arranged at regular intervals in a main scanning direction, and each solid-state image sensor scans a main scanning area. Figure 1 shows 1. An example of this is shown below.

'ig1 In Figure 1, light source 1 uniformly illuminates original image 2 with N
The reflected light is converted into COD by the condensing lens 3.4.
By switching the changeover switch 7 in the sensor select circuit 10, the analog image signal of the solid-state image sensor 6 and the analog image signal of the solid-state image sensor 6 are added to the solid-state image sensor 5.6 and photoelectrically converted into an image signal. Image signals are taken out alternately and continuously and amplified by an amplifier 8 to an appropriate amplitude value. The A/D converter 9 converts the analog image signal amplified by the amplifier 8 into a digital image signal while being synchronized with the sensor switching timing notified from the sensor select circuit 1°. Thereafter, the image signal undergoes processing such as gradation correction by the digital signal corrector 11, and is output to an external device, memory, or the like.

Note that the sub-scanning is performed by a sub-scanning feeding means (not shown) in a direction perpendicular to the paper surface.

However, in the above configuration, the solid-state image sensor 6.
It is required that the positions of the solid-state image sensor 56 and the condensing lens 3.4 are adjusted mechanically accurately so that the seams of the reading areas 6 and 6 fit perfectly. However, this adjustment is generally difficult, and furthermore, even if the adjustment is made once, subtle positional deviations may occur again due to physical vibrations such as transportation, movement, or temperature changes. As a result, there is a drawback that image information at the joint between the solid imager and the screen may be duplicated or missing.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and aims to provide an image reading device in which image information at the joint portion of a plurality of solid-state image sensors is not omitted or missing. .

Structure of the Invention The present invention provides a changeover switch that successively extracts image signals from a plurality of solid-state image sensors such as CODs, a sensor selection circuit that controls the changeover switch, and an A that converts an analog image signal into a digital image signal. A/D converter, and a seam control circuit that receives notification of switching timing of the solid-state image sensor from the sensor select circuit and adjusts image information of the seam portion of the solid-state image sensor by controlling the A/D converter. By overlamping the reading areas of adjacent solid-state image sensors and deleting the overlapping image information, the image reading device is configured so that image information at the seam is not duplicated or missing. .

DESCRIPTION OF THE EMBODIMENTS FIG. 2 is a block diagram of an image reading apparatus according to an embodiment of the present invention. In Fig. 2, 1 is a light source, 2 is an original image, 3 and 4 are condensing lenses, 5.6 is a solid-state image sensor such as COD, 7 is a changeover switch, 8 is an amplifier, and 9 is an A/
D converter 11 is a digital signal corrector, which has the same configuration as in FIG.
It is arranged so that 3 occurs. 101L is a sensor selection circuit which will be described later, and 12 is a joint control circuit for controlling the A/D converter 9.The detailed block configuration thereof will be explained below with reference to FIG. 3.

Note that after extracting the image information from the solid-state image sensor 6 (hereinafter abbreviated as a mu sensor), the solid-state image sensor 6
(hereinafter abbreviated as B sensor), and the sampling pulse applied to the A/D converter 9 is an image signal readout clock (hereinafter abbreviated as readout clock) applied to the solid-state image sensor 6.6. A clock pulse synchronized with

In FIG. 3, 14 is a head image signal that is not A/D converted among the image signals read by the A processor 6 (a human sensor off counter that counts the number of accompanying readout clocks), and 15 is the image signal read by the human sensor 5. 16 is the A sensor on counter that counts the number of read clocks accompanying the image signal to be A/D converted, and 16 is the A sensor on counter of the image signal read by the B sensor 6.
/B sensor off counter that counts the number of readout clocks accompanying the head image signal that is not converted to D; 17 is the B sensor 6;
18 is a flip-flop that is set only during the period when the human sensor on counter 15 is counting the set number of readout clocks. 19 is a flip-flop that is set only while the B sensor on counter 7 is counting the number of set readout clocks; 20 is an OR gate that takes the logical sum of the output of the flip 7O block 18 and the output of the flip flop 07 and 19; 23
is an AND gate that performs the logical product of the output of the OR gate 20 and the read clock.

The operation of the image reading device configured as above will be described below.

Note that since the operation of the amplifier 8 is the same as that of the conventional example, a description thereof will be omitted.

First, the sensor selection circuit 10 sends information about which image information from the human sensor 6 and the B sensor 6 is input to the A/D converter 9 to the A sensor off counter 14 and the B sensor off color counter 16. At the same time, the changeover switch is turned on. Now, if image information from the human sensor 6 is input to the A/D converter 9 and I', only the human sensor off counter 14 is activated. The number of readout clocks associated with the head image signal that is not subjected to human/D conversion among the image signals read by the human sensor 6 is stored in advance in the human sensor off counter 14.

The human sensor off counter 14 counts the number of readout clocks for the image information sent from the input sensor S from the beginning, and when the number of readout clocks has been set in advance (7),
At the same time as the flip 70 knob 18 is set, the human sensor on counter 16 is notified that counting has been completed. On the other hand, the number of read clocks associated with the image signal to be A/D converted among the image signals read by the sensor 6 is also set in advance in the A sensor +, t counter 16.

The human sensor on counter 16 is the human sensor off counter 14.
Upon completion of counting, the number of readout clocks sent from the memory sensor 6 begins to be counted, and when the preset number of readout clocks is reached at time T+, the flip-flop 18 is reset. As a result, flip 70・
The output waveform of the 7p 18 is the waveform shown in FIG. 4 (&).

When the image information of the B sensor e is input to the A/D converter 9, a similar operation is performed to input the F'J block flop 19.
The output waveform becomes the waveform shown in FIG. 4 (bl).The OR gate 2o takes the logical sum of the outputs of the flip-flops 18 and 19, so the output waveform becomes the waveform shown in FIG. 4(C). Furthermore, the AND gate 23 performs a logical product of the output of the OR gate 2o and the read clock, and applies the result as a sampling pulse to the A/D converter 9. When the waveform 1cl in FIG. The operation of the A/D converter 9 is permitted, and the operation of the A/D converter 9 is prohibited in the reset state.

As a result, an image signal that undergoes A/D conversion and an image signal that does not undergo A/D conversion are generated. Figure 5 shows this situation. 21
22 is an image signal output from the B sensor 6, and 22 is an image signal output from the B sensor 6. The image signal in area 1 is an image signal in which the A sensor off counter 14 is counting the number of read clocks, but during this period, the FRI-7F-7F 18 is in a reset state and the A/D converter 9
does not operate, so it is an image signal that is not subjected to Mu/D conversion. The image signal in the area (3) is an image signal in which the sensor on counter 15 is counting the number of read clocks, but during this period, the flip-flop 1 is in the set state and the A/D
Since the converter 9 operates, the image signal is subjected to human/D conversion. The image signal in the area of ■ is the human sensor on counter 1.
6 is the image signal after counting the number of read clocks, but during this period, the flip 70 knob 18 is reset again and the A/D converter 9 does not operate, so the human /
This is an image signal that is not D-converted. Similarly, for the B sensor, the image signals of the region .largecircle.

In this way, the image signal of the region (1), which is the sum of the field region and the V region, is A/D converted. Only the image signal thus subjected to λ/D conversion is applied to the digital signal corrector, undergoes processing such as gradation correction, and is output to an external device, memory, or the like.

In other words, the number of readout clocks sent to the human sensor on counter 16 and the B sensor off counter 16 in advance can be set in units of one readout clock using a dim switch, etc., so that the image signal output from the A sensor S 21 and the image signal 22 output from the B sensor 6
The image information at the joint between the two can be easily adjusted pixel by pixel so that it is not severe or missing. In addition, since the number of readout clocks preset in the A sensor off counter 14 and the B sensor on counter 17 can be set in advance in units of one readout clock, the entire area of the image signal to be subjected to M/D conversion in the area (■) is also 1 This can be easily determined in units of read clocks.

As described above, according to this embodiment, the image information at the joint portion of the solid-state image sensor can be adjusted on a pixel-by-pixel basis so that it is not severe or missing, and the total number of pixels to be read can also be adjusted on a pixel-by-pixel basis.

Furthermore, Fig. 6 shows the circuit diagram of the sensor select circuit 10tL, and Fig. 7 shows the circuit diagram of the sensor off counter 14 and the sensor select circuit 10tL.
A circuit diagram of the sensor-on counter 15 and the flip-flop 1 is shown in FIG. Furthermore, although this embodiment is configured to use two solid-state image sensors, it is not limited to two, and can be extended to any number of solid-state image sensors.

Effects of the Invention As described above, the present invention arranges a plurality of reading means spatially at regular intervals so that the reading areas of adjacent reading means overlap, and furthermore, two reading means are arranged for each reading means. A counter is provided, the first counter counts the number of readout clocks attached to the image signal that is not A/D converted, and the second counter counts the number of readout clocks attached to the image signal number that is not A/D converted. By configuring the control means, it is possible to easily adjust the image information at the joint part of the reading means in units of 1 pixel so that the image information is not immediately lost or missing (and the total number of pixels to be read can also be easily adjusted in units of 1 pixel). can.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional image reading device using a plurality of solid-state image sensors, FIG. 2 is a block diagram of an image reading device according to an embodiment of the present invention, and FIG. 3 is a successor of the same device. A block configuration diagram of the grain control circuit, FIG. 4 is a timing waveform diagram of the main signals of the grain control circuit, and FIG. S is a conceptual principle diagram of how to connect image signals according to this embodiment. 7 and 8 are circuit diagrams of main parts of the image reading device, respectively. 3.4. - Condensing lens, 6,6... - Solid-state image sensor, 7- Selector switch, 9... Person/D9 switch,
10 - Processor select circuit, 12 Seam control circuit, 14...A sensor on counter, 15...
- A sensor off counter, 16...B sensor off counter, 17...B sensor on counter, 18.
19...Flip-flop, 20...Or gate. Name of agent: Patent attorney Toshio Nakao and 1 other person
Ward 8-cl
(,)Figure 5■

Claims (2)

[Claims] (1) first and second reading means arranged so that their reading areas overlap each other; and a switch means for switching input of analog read information sent from the first and second reading means; analog/digital conversion means for converting the analog read information inputted through the switch means into digital read information; and the switch means and analog/digital conversion means depending on the reading states of the first and second reading means. An image reading device comprising a control means for controlling. (2) The control means includes, for the first and second reading means, a first counter that counts a predetermined number of image signal readout clocks to be applied to the first and second reading means; a second counter that counts the image signal readout clock a predetermined number of times immediately after counting ends; a flip-flop that is set only while the second counter is counting;
Claim 1, further comprising a sensor selection circuit that notifies the first counter of the switching of the first and second reading means at the same time as switching the switching means.
The image reading device described in Section 1.