JPH04322556A - Picture reader - Google Patents

Abstract

PURPOSE:To read an accurate picture data even when a feeding speed of an original is changed. CONSTITUTION:Let a feeding time T of one picture element of an original read by a CCD image pickup element 5 when an original feeding speed V is a fastest original feed speed V1 be T1, then the scanning time for scanning the CCD image pickup element 5 once is set to T1 and in the case of V<V1, the CCD image pickup element 5 is scanned by the time T1 and the charge of the CCD image pickup element 5 is discharged for a time (T-T1).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device for reading an image of a document in a facsimile machine or the like.

0002

2. Description of the Related Art Conventionally, as an image reading device, a plurality of CCs are arranged in a row at positions that receive image light from a document.
D image pickup device, scan control means for transferring charges of these CCD image pickup devices and outputting image data, and document feed speed detection means for detecting the feed speed of the document and providing it to the scan control device. An image reading device having the following is known. In this type of conventional image reading device, when the document feeding speed is determined to be constant by the document feeding speed detection device, the scanning control device scans the CCD image sensor for a constant scanning time.

0003

[Problems to be Solved by the Invention] However, in the conventional image reading device, when the feeding speed of the original is constant, the scanning control means scans the CCD image sensor in a fixed scanning time. Accurate data of the image if the speed changes
The problem is that the data cannot be read. SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading device that can read accurate image data even when the document feeding speed changes.

0004

[Means for Solving the Problems] According to the present invention, a plurality of CCs are arranged in a row at positions receiving image light from a document.
D image pickup device, scan control means for transferring charges of these CCD image pickup devices to output image data, document feed speed control means for controlling the feed speed of the document, and scan control device for controlling the feed speed of the document. In the image reading apparatus, the scan control means detects the speed of the document and supplies the detected speed to the scan control means, and the scan control means detects the speed of the document when the document feed speed V is the largest value V1. When the feeding time T for one pixel of the document read by the device is T1, the scanning time for scanning the CCD image sensor once is T1
, and when V<V1, the CCD image sensor is scanned at a time T1, and the charge of the CCD image sensor is discharged at a time (T-T1). It will be done.

[0005] In addition, at the position receiving the image light from the original,
A plurality of CCD image sensors arranged in a row and these CCs
D scan control means that transfers the charge of the image sensor to output image data; document feed speed control means that controls the feed speed of the document; and scan control means that detects the feed speed of the document and performs the scanning. In the image reading apparatus, the scanning control means detects one of the documents read by the CCD image sensor when the document feed speed V is the largest value V1. When the pixel sending time T is T1, when V=V1, T
The CCD image sensor is scanned multiple times in one hour, and the time of one of the scans is set as T2, and only the image data in the scan of this scan time T2 is valid, and even if V<V1, the time T1 is An image reading device is provided, characterized in that the CCD image sensor is scanned a plurality of times, one scanning time is T2, and only the image data in the scanning for this scanning time T2 is valid. It will be done.

[0006]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the image reading device of the present invention includes a document feeder 1, a motor drive device 2, a main controller 3, a scanning device 4, and a plurality of CCD image sensors 5. There is. The document feeding device 1 is a device that feeds a document to be read using the driving force of a motor 1a, and can control the document feeding speed by changing the rotational speed of the motor 1a. . This motor 1a is driven by a motor drive device 2. This motor drive device 2 is controlled by a main control device 3. The main controller 3 controls the motor drive device 2 in response to a start signal and signals from other devices (not shown), and controls the motor drive device 2 or the document feeder 1. The scanning device 4 is controlled by detecting the document feeding speed data from the original document feeding speed and determining the document feeding speed. This scanning device 4 transfers the charge of the CCD image sensor 5 to output image data. CCD
The image sensors 5 are arranged in a row at positions that receive image light from the original.

Next, the operation of one embodiment of the image reading apparatus of the present invention will be explained in detail with reference to FIG. The main control device 3
By controlling the scanning device 4 based on the document feeding speed data of the document feeding device 1, the CCD image pickup device 5 is controlled when the document feeding speed V is the largest value V1. The feeding time T for one pixel of the original to be read is T
1, the scanning time for scanning the CCD image sensor 5 once is set to T1, and when V<V1, the CCD image sensor 5 is scanned for the time T1, and (T
- The charge of the CCD image sensor 5 is discharged at time T1).

Next, another embodiment of the present invention will be described in detail with reference to FIG. As shown in FIG. 3, the image reading device of the present invention includes a document feeder 1, a motor drive device 2, a main controller 3, a scanning device 4, a CCD image sensor 5, and a selection device 6. Equipped with The document feeding device 1, motor drive device 2, scanning device 4, and CCD image pickup device 5 in the embodiment shown in FIG. 3 are the same as those in the embodiment shown in FIG. The selection device 6 receives an output signal from the CCD image sensor 5 and is controlled by the main control device 3.

Next, the operation of the embodiment of the image reading apparatus of the present invention shown in FIG. 3 will be explained in detail with reference to FIG. By controlling the selection device 6, the main control device 3 sets the feeding time T of one pixel of the document read by the CCD image sensor when the document feeding speed V is the largest value V1 to be T1. In this case, when V=V1, the CCD image sensor 5 is scanned a plurality of times during time T1, and the time of one of the scans is set as T2, and this scanning time T2
Only the image data in the scan is valid, and even if V<V1, the CCD image sensor is scanned multiple times in time T1, and the time for one of the scans is T2, and the scan for this scan time T2 is performed. Only the image data in the scan time T2 is valid, and the scan time other than the scan time T2 (T
2+a1), (T2+a2), (T2+a3), (T2
+a4) and the image data in one of the two scan times T2 within time T are invalidated.

0010

Effects of the Invention The image reading device of the present invention can keep the scanning time required to obtain image data constant even when the document feeding speed changes, so it is possible to accurately capture images. Data can be read.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the embodiment shown in FIG. 1;

FIG. 3 is a block diagram showing another embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the embodiment shown in FIG. 3;

[Explanation of symbols]

1. Original feeder 2 Motor drive device 3 Main control device 4 Scanning device 5 CCD image sensor

Claims (2)

[Claims] Claim 1: A plurality of CCD image sensors arranged in a row at positions receiving image light from a document, and these CCDs.
scan control means for outputting image data by transferring charges of an image sensor; document feed speed control means for controlling the feed speed of the document; and scan control means for detecting the feed speed of the document. In the image reading apparatus, the scanning control means detects the C when the document feeding speed V is the largest value V1.
The feeding time T of one pixel of the original document read by the CD image sensor
is T1, the scanning time for scanning the CCD image sensor once is set to T1, and when V<V1, the CCD image sensor is scanned for the time T1, and (T
- An image reading device characterized in that the charge of the CCD image sensor is discharged at time T1). 2. A plurality of CCD image sensors arranged in a row at positions receiving image light from a document, and these CCDs.
scan control means for outputting image data by transferring charges of an image sensor; document feed speed control means for controlling the feed speed of the document; and scan control means for detecting the feed speed of the document. In the image reading apparatus, the scanning control means detects the C when the document feeding speed V is the largest value V1.
The feeding time T of one pixel of the original document read by the CD image sensor
is T1, and when V=V1, T1
The CCD image sensor is scanned multiple times per time, the time of one of the scans is set as T2, and only the image data in the scan of this scan time T2 is valid, and even when V<V1, the image data is scanned at time T1. An image reading device characterized in that the CCD image sensor is scanned a plurality of times, one scanning time is T2, and only the image data in the scanning for this scanning time T2 is valid.