JPS60157A - Picture input device - Google Patents

Abstract

PURPOSE:To impove the operability of a picture input device by reading the pictures exposed by a light source, detecting the read position and controllig the lighting of the light source with the detected output. CONSTITUTION:The light given from LED23 arrayed in the lengthwise direction of a picture reading head 1 is exposed to an original 20 via a supporter 2 of a light transmitting material. The reflected light sent from the original 20 is formed into images on the photodetecting surface of a sensor 21. The picture analog signal given from a sensor part 40 is converted into the digital signal by an A/D converter 45 and then binary coded to be supplied to a picture memory 52. While a memory driving circuit 51 supplies the pulse output given from a reference oscillator 49 in the form of a main and secondary scan clocks, and at the same time a slit end detection signal A. The addresses of the memory 52 are successivly decided with each output of the signal A, and the start of scan is decided by a scan position detecting circuit 53. The lighting of the LED23 is controlled with the detected output of the circuit 53. Thus the operability is improved for a picture input device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital image input device for copying machines, facsimile machines, electronic files, etc., and particularly to a small-sized, manual tie 7° image input device.

Recently, digital image input (detection) methods using reduction optical systems and image sensors such as GCD, and
A contact line sensor has been proposed in which a one-to-one optical sensor array is placed in close contact with a document to read the document. Using this contact line sensor eliminates the need to secure space for a conventional optical system, and is particularly effective in reducing the weight and size of the device.

Book iE! The present invention provides an image input device that takes advantage of the compactness of the contact line sensor, scans nine lines, and reads image information.

FIG. 1 shows a schematic diagram of an image reading device according to the present invention.

A reading head housing a close contact fin sensor is reciprocally coupled to a support body 2 having a sliding mechanism 3, and can be opened and closed by an opening/closing joint 7 with respect to a document table 6 as a body. The original to be read is placed on a support 2 made of transparent material such as glass.
The image is inserted face-up between the document table 60 and the image area 5, and is manually scanned line by line in the longitudinal direction of the image area 5 and read out on the same side (1-).

In Figure 2! 11' shows the cross-sectional structure of the east head 1. Light from the LEDs 23 arranged in the longitudinal direction of the head passes through the transparent material (glass) support 2 and exposes the original 20. The reflected light from the original 20 is imaged by a short focus imaging element array (hereinafter referred to as an imaging array) 22 on the light receiving surface of a sensor 21 which outputs a signal according to the incident light.

FIG. 6 shows the detection surface (light receiving surface) of KH191, rehead 1. As shown in the figure, in addition to the LEDs 23 arranged in an array for reading the original image, an LED 3 () for detecting the scanning position is integrally provided. LED for scanning position detection! . It is provided integrally with the image reading light receiving element at the position shown in FIG. In this embodiment, the longitudinal direction of the head length is 3.
20 mm, the photodetector pitch is 62.5μ (16pθ
1) has a resolution (5120 pixels/line), and therefore, for preferable image reproduction, it also has a resolution of 62.5μ in the scanning direction.
It is necessary to detect the position of the read head 1 in pitch.

In order to detect slit 4 with a slit width of approximately 50 μm and a duty ratio of 50, the light receiving surface of the light receiving element for position detection is 40 μm.
The door was 500 μm x 500 μm. As a result, even if the scanning speed varies, image data of 5120 pixels for one line can be transferred and photocurrent can be accumulated every time the position detector detects a slit, and data can be recorded reliably. Furthermore, since the position of the reading head 1 is optically detected,
The light receiving section and light source for position detection can be realized in the same process as the formation of the image sensor section, which is very convenient in terms of production.7b.

Next, Fig. 4 is a diagram showing the circuit configuration of the control section. The detection current of the photodiode 46 is expressed as serial data by sequentially connecting the 5120 switches 5W42 connected to each other by the shift output of the shift register 41 driven in synchronization with the output of the reference oscillator 49. The detection current is connected to the image analog signal by the amplifier 44 and reaches the signal level 2 (L7).

-- On the other hand, the operation start timing of the shift register 41 is determined by the slit end detection signal -@■ obtained by amplifying and waveform shaping the output of the light receiving element 47 for scanning position detection by the gate 48.

FIG. 5 shows the signal waveforms mentioned above and at the zero point.

Since it is generally operated manually, the signals read from the slits 4 arranged at equal intervals are generated at irregular intervals as shown in (2), and the counting circuit 50 starts operating at the rising edge of the signal. The counting circuit 50 counts clock pulses from the reference oscillator 49 from the rising edge of the slit end detection signal (2), and inputs a control signal indicated by ◎ to the shift register 41 over the time required to read one line. This control signal O
The 5ws 42 are sequentially connected in synchronization with the clock pulse output from the reference oscillator 49 during the "H" level period, and one line of image data is serially output with the waveform shown in (2).

In FIG. 4, the image analog signal ■ has ν conversion circuits 45
After being converted into a digital value of predetermined bits and further binarized by a predetermined image signal processing circuit 46, it is input as video fifth data to an image memory 52 having a storage capacity of, for example, one original document.

On the other hand, the memory drive circuit 51 sequentially determines the address of the image memory 52 by inputting the pulse output from the reference oscillator 49 and the slit edge detection signal ■ as the main scanning clock and sub-scanning clock. Explaining the control of the light source according to the present invention Generally, before starting scanning, this type of device requires turning on the main power and performing operations such as switching on and off to turn on the light source, etc. , because the reading head 1 is manually scanned as mentioned above, it is desirable to simplify the operation by omitting other operations as much as possible. Therefore, the light source LEI for scanning position detection is synchronized with the main power supply in '50. On the other hand, when the start of scanning is detected, the image reading light source LED 23 is turned on.

4th rg4k jr and 56 is the image reading light source LE
This is the dotsuki circuit of D25, and its internal configuration is shown and explained in FIG. There is a counter that counts the constant period A pulses output from the reference oscillator 533, and when the gun picking head 1 starts scanning and a predetermined number of pulses are input to the counter 531, the flip-flop 564
The uj force of is set. This output lights up the image reading light source LED 26. On the other hand, the reference oscillator 566
A counter 562 that counts constant periodic pulses is reset by a pulse generated in response to slit reading, and if a predetermined number of counts are performed after that, that is, if there is no new pulse input due to scanning within a predetermined time, the image is read. It is determined that this is not done, the flip-flop 564 is reset, and the light source LED 26 is turned off. This can prevent unnecessary lighting due to vibration or the like. Note that the fine image reading head 1 of the manual scanner may be moved at a constant speed by a motor or the like.

In this way, the image reading head 1 is equipped with a light source for scanning position detection and a pair of sensors, and the light source for scanning position detection is kept in the Tsunematsu lighting state when the control power is turned on, and the start of scanning is constantly monitored and the start is detected. By doing so, the light source for image reading was turned on, resulting in a significant improvement in operability. It goes without saying that the light source is not limited to LEDK.

As described above, since the K11ij image exposure light source is turned off except when reading an image, wasteful power consumption is prevented and the life of the light source is extended.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an image reading device according to the present invention, FIG. 82 is a diagram showing the cross-sectional structure of the reading head, FIG. 3 is a diagram showing the detection surface of the reading head, and FIG. 4 is a diagram showing the circuit configuration of the control section. 5 is a waveform diagram, and FIG. 6 is a lighting circuit diagram of an image reading light source, in which 1 is a reading head, 2 is a transparent material support,
4 is a slit, 21 is a sensor, and 26 is an LED. Applicant Canon Co., Ltd. No. 30

Claims (1)

[Claims] It has a light source for reading an image, a reading means for reading the image exposed by the light source, and a means for detecting the position of the reading means, and is configured to control the lighting of the light source based on the output of the position detecting means. An image input device characterized by: