JPH0591301A - Image reader - Google Patents

Abstract

PURPOSE:To provide an image reader capable of easily confirming the entire image regardless of the use of a display device which has a resolution lower than that of the line sensor of a read part and has a small number of picture elements. CONSTITUTION:Picture information of a document read in by an image sensor is not only stored in a memory area 2 for ordinary display but also reduced in a proportion of the display picture element pitch of the display device to the read picture element pitch of the image sensor by a reduction processing circuit 3, and reduced picture information is stored in a memory area for unmagnification display. Thereafter, picture information stored in respective memory areas are switched by a switching circuit 5 and are displayed on a display device 6.

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 having a display device for displaying a read image.

[0002]

2. Description of the Related Art In recent years, an image on an original is read by an image sensor, the read image information is stored in a memory, and the information in the memory is sent to an image processing device such as a word processor or a personal word processor for image processing. A small-sized image reading device for performing the above has been put into practical use.

In this type of image reading apparatus, a conventional liquid crystal display element for displaying image information in the memory so that it can be visually confirmed whether or not the image information is properly read and is inputted in the memory. There is a device provided with an image display unit including the above. (JP-A-01-1
In the image reading apparatus as described above, the display resolution in the main / sub scanning direction of the display unit is set to that of the image sensor in the reading unit in order to facilitate comparison between the display image after reading and the original image. It is common to use the same reading resolution.

However, most of the image sensors used in recent facsimiles and image readers are line sensors, and the resolution of images currently in practical use is 8 pixels / mm or more. When reading an image of A6 size with such a line sensor, for example, in the case of 8 pixels / mm, 832 pixel elements are required in the main scanning direction (horizontal direction). Therefore, in order to display and compare the image information read from these line sensors in the same size as the original image, as a display device, a display device having the above resolution and the number of pixel elements in the horizontal direction, for example, Liquid crystal display elements are desirable, but at present there is no liquid crystal display element with such a fine resolution and many pixel elements in the market, and even if it can be realized, it will be very expensive. Will.

On the other hand, when applying a liquid crystal display element which is relatively inexpensive but has a low resolution and a small number of pixel elements in the general market, one pixel of the line sensor, for example, its pixel pitch is 125 μm (8 pixels / mm). ) Output as it is for one pixel of the display element, for example, a pixel pitch of 500 μm (2 pixels / m
m) is output as shown in FIG.
The image 32 magnified 4 times is displayed on the display device 25. This is effective for confirming reading of a fine portion on the document, but there is a problem that it is difficult to confirm the entire image.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned circumstances, and uses a display device having a lower resolution and a smaller number of pixel elements than a line sensor of a reading section. The present invention provides an image reading device capable of easily confirming the whole image as needed.

[0007]

An image reading apparatus of the present invention displays an image sensor for reading a document, a memory for storing the image information read by the image sensor, and the image information stored in the memory. In an image reading device having a display means, a first memory area for storing image information read by the image sensor, and the image information read by the image sensor for the reading pixel pitch of the image sensor An image switching unit that includes an image reducing unit that reduces the display pixel pitch, and a second memory area that stores the image information reduced by the image reducing unit, and that switches the output of each memory region to the display unit. It is characterized by having.

[0008]

In the image reading apparatus of the present invention, the image information of the original read by the image sensor is stored in the first memory area, and the image information is displayed by the image reducing means with respect to the read pixel pitch of the image sensor. The image is reduced at a rate of the display pixel pitch of the device, and the reduced image information is stored in the second memory area. After that, the image information stored in each of the memory areas is switched and displayed on the display means by the image switching means as needed.

[0009]

1 is a circuit block diagram of an embodiment of an image reading apparatus of the present invention.

In FIG. 1, the image information read by the line sensor is stored in the normal display memory area 2 through the line sensor interface 1, and the reduction processing circuit 3 displays the read pixel pitch of the image sensor. The image is reduced at a rate of the display pixel pitch of the device and stored in the memory region 4 for equal-magnification display. After that,
The switching circuit 5 switches and displays the image information stored in each memory area on the display device 6. A control circuit 7 controls the entire apparatus.

The processing operation of the above circuit will be described in detail with reference to the drawings. (1) First, the image signal output from the line sensor interface 1 will be described.

In this embodiment, the signal from the line sensor interface 1 is a monochrome binary digital signal, and the image data for one line as shown in the image signal 19 of FIG. 4 has a resolution of 8 pixels / mm. Is output serially.

The image signal 19 shown in FIG. 4 is a black signal if the level is [1] at the rising edge of the clock 20 shown in FIG. 4 after the start pulse 21 is generated, and is white if the level is [0]. Is shown. Further, the state when this signal is viewed as an image is shown in the first line of FIG. (2) Next, a process of storing the image information input via the line sensor interface 1 in the normal display memory area 2 will be described.

During image reading, the image signal is RA
In the normal display memory area 2 made up of M or the like, one read pixel is stored in the form of 1 bit, and at the same time, display image data is displayed from this memory area by 1 display pixel per 1 bit through the image switching means 5. It is output to the device 6. Assuming that the display device 6 has 2 pixels / mm, the display device 6 has a size of about four times as large as the read image information, as in the conventional example (FIG. 6). , The "ABC" portion of the document) is enlarged and displayed. (3) Further, a specific configuration and operation of the reduction processing circuit 3 will be described with reference to FIG.

In the figure, a B / W clock gate 8
Generates one pulse when a black pixel signal of the pixel signals output from the line sensor interface 1 is input, and the pulse is generated by the pixel counter 1
Count as 1. Also, column count 9 and row count 1
0 generates a control pulse every 4 pixels and every 4 lines.

Below, an example of the operation in the case of reducing the image information of FIG. 3 to 1/4 will be described in detail.

The image information is divided into blocks of 4 × 4 pixels (for example, 17), the number of black pixels in each block is counted, and the counted number is set to the preset number in the count value comparison circuit 16. By comparing the magnitudes, a binary signal for one pixel of black is obtained when the number of blacks is large and white when the number of blacks is small.

That is, the image signal 19 of the first line from the line sensor is controlled by the column count 9 to count the number of black [1] by the B / W clock gate 8 and the pixel counter every 4 pixels. Number is count memory 1
4 is stored. Next, when the signal of the second line is sent, the count number stored in the first line is read from the count memory 14 to the pixel counter 11 for every 4 pixels in the same block as the 4 pixels, and Is added and counted, and the obtained number of counts is stored in the count memory 14 again.

The above processing is performed for the third and fourth lines. That is, on the fourth line, when the count for each 4 pixels is completed, the count number for 4 × 4 pixels is output. This output is sent to the count value comparison circuit 16 to obtain black or white for one pixel, that is, a binary output of 1 or 0 depending on the size of the count number. This makes 4x
An image for 4 pixels is reduced to 1 pixel. The above operation procedure is shown in FIG. 7 for reference.

The image data obtained by the image reduction processing as described above is stored in the same-size display memory area 4, and the switching circuit 5 produces an image 26 having substantially the same size as the original image 22 as shown in FIG. It is displayed on the display device 25. In this display state, since the display pitch of the fine display portion is rougher than the reading pitch, the saturation of the image is lacking, but the input confirmation of the entire image can be confirmed.

The switching circuit 5 is the switch 3 shown in FIG.
Switching control is performed by 0. Also,
In the circuit of this embodiment, a logic circuit is used for real-time operation, but a high-speed microcomputer,
It is also possible to operate like a software using a CPU or the like.

A second embodiment of the image reading apparatus of the present invention will be outlined below. In this embodiment, 8 pixels / mm
Line sensor that can read 16 gradations at a resolution of 1 pixel and output a 4-bit digital signal per pixel, and can display 16 gradations of 1 pixel at a resolution of 2 pixels / mm and input 4-bit image data It is possible to realize a display device that can do this.

The difference between this embodiment and the above-mentioned embodiment is that the above-mentioned embodiment has two gradations, the number of blacks in the 4 × 4 block is counted, and the black-and-white in the reduced display is determined by the number. On the other hand, in this embodiment, the gradation numbers of each pixel in the 4 × 4 block are all added, and the added number is converted into the gradation number of the display unit and stored in the reduced display memory and stored in the display device. It outputs it. That is, by changing the B / W clock gate and the pixel counter to an adder circuit and the count value comparison circuit to a shift circuit, the gradation degrees of 4 × 4 pixels are all added through the same procedure as in the above embodiment, and the output The added number (8-bit data) is made into 4-bit data by the shift circuit, and this is stored and displayed as the gray scale number of 1 pixel for equal-magnification display.

Since the gradation display can be performed in this manner, the unity-magnification display is superior to the unity-magnification display in the above-described embodiment in the fineness of saturation, and there is an advantage that the brightness adjustment at the time of reading can be easily performed.

[0025]

According to the image reading apparatus of the present invention, the entire image can be confirmed as necessary while using a display device having a lower resolution and a smaller number of pixel elements than the line sensor of the reading section. Can be improved.

[Brief description of drawings]

FIG. 1 is a circuit configuration block diagram of an embodiment of an image reading apparatus of the present invention.

FIG. 2 is a block diagram of the reduction processing circuit of FIG.

FIG. 3 is a diagram showing a state in which a read image is divided into 4 × 4 blocks in an embodiment of the image reading apparatus of the present invention.

FIG. 4 is a diagram showing an example of signals from a line sensor interface in an embodiment of the image reading apparatus of the present invention.

FIG. 5 is a state diagram during a reading operation in the embodiment of the image reading apparatus of the present invention.

FIG. 6 is a state diagram during a reading operation in the conventional image reading apparatus.

FIG. 7 is a diagram showing an operation procedure of a reduction processing circuit in an embodiment of the image reading apparatus of the present invention.

[Explanation of symbols]

 1 line sensor interface 2 memory area for normal display 3 reduction processing circuit 4 memory area for 1 × display 5 switching circuit 6 display device 7 control circuit

(72) Inventor Hiroshi Iwata 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Satoshi Ishida 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (1)

[Claims] 1. An image reading apparatus comprising an image sensor for reading a document, a memory for storing image information read by the image sensor, and a display unit for displaying the image information stored in the memory, wherein the image A first memory area for storing image information read by the sensor; and image reducing means for reducing the image information read by the image sensor at a ratio of a display pixel pitch of a display device to a read pixel pitch of the image sensor. An image reading apparatus comprising a second memory area for storing image information reduced by the image reducing means, and image switching means for switching output of each memory area to the display means.