JPS6394775A - Adjusting method for read effective range of ccd sensor - Google Patents

Abstract

PURPOSE:To adjust the read effective range with high accuracy in a very short time by adjusting the position of an effective data signal on a time base in response to the position of the time base in the read range of a CCD sensor. CONSTITUTION:A black level data is given at the middle of the read effective range of a read original and in other case, the white background read original 1 is read. As a read data A' read from a CCD sensor 4 in response to a shift signal C', only a read data signal D exists. A timing generator 6 outputs effective data signals D', G' (effective data signals before correction) and a center signal (center signal before correction) to the shift signal C'. The read data D' is not located within the effective data signal D'. The operator observes a center signal G' on a synchroscope 10 and the read data signal D from an amplifier 9 and adjusts a dip switch 8 so as to make the center signal G' coincident with the data signal D.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to equipment using a charged coupled device sensor (hereinafter referred to as a CCD sensor), such as a facsimile machine or an electronic whiteboard device, and more specifically, The present invention relates to a method of adjusting the effective reading range of a reading object such as a computer or a board.

(Prior Art) FIG. 4 is a schematic diagram showing an optical system of a facsimile machine. In the figure, a document 1 to be read traveling in the direction of the arrow in the figure is irradiated with light from a light source (not shown), and the reflected light 2
After the light is focused by the condenser lens 3, the light is received by the CCD sensor 4. In the figure, W indicates the effective reading range of the original document 1 to be read.

FIG. 5 is a diagram for explaining a conventional method for adjusting the effective reading range in the optical system. The diagram shown in (A) of the figure shows the read data output from the CCD sensor 4 in FIG. Reading effective bit length (corresponds to the effective range W of reading document 1)
, b indicates the extra bit length on the left side, and C indicates the extra bit length on the right side. The signal shown in (b) is an electrical signal (hereinafter referred to as a valid data signal) indicating the effective range (also corresponding to the reading effective range W) of the read data (a) of the CCD sensor 4. Moreover, the signal shown in (c) is the CCD
A shift signal for shifting the read data in analog form from the sensor 4 into an analog shift register (not shown) that streams bit-serially.

(E) and (F) respectively show the read data from the CCD sensor 4 shifted by the shift signal (C).

Here, when the effective reading range W of the document matches the effective range a of the reading data (a) of the CCD sensor 4, the reading data shown in (a) is obtained.

Therefore, there is no need to adjust the effective reading range. On the other hand, when the two are out of alignment, the read data of (E) or (E) is obtained. (E) shows the case where the read data corresponding to the effective reading range W of the document is shifted by B bits, and (F) shows the case where it is shifted by C bits. When such a shift occurs, it has conventionally been necessary to mechanically adjust the optical system so that the read data matches the range of the effective data signal (b). For example, in the case of (e), the read data is moved to the b bit distribution, and (
), the optical system was adjusted so as to move to the C-bit partial pressure.

The first method for this adjustment is to move the CCD sensor 4 in the vertical direction of the page in the example of FIG. 4 (hereinafter referred to as
In addition to adjusting the optical axis so that the lines of the original to be read 1 and the CCD sensor 4 are aligned, and adjusting the focus of the condensing lens 3, the CCD sensor 4
There are focal point alignments that move the upper image formation, and shading adjustments that uniformize the amount of light from a light source (not shown).

(Problem to be Solved by the Invention) However, according to the conventional method for adjusting the effective reading range, other elements of the optical system, such as the optical axis, shading, and lens focusing, can be adjusted by mechanically aligning the sensor. This poses a problem in that it requires extremely complicated and troublesome work.

(Means for Solving the Problems) The present invention optically scans an object to be read with a CCD sensor, and generates a valid data signal for determining the range of valid data in the output signal of the CCD sensor, and 9 objects to be read. The present invention relates to a method of adjusting the effective reading range of the CCD sensor to match the effective reading data of the CCD sensor.

According to the present invention, firstly, the generation time of the valid data signal is made to follow the change in the generation time of a timing signal that always has a predetermined phase relationship with respect to the valid data signal.

Then, the adjustment is performed by adjusting the generation time of the timing signal so as to coincide with the generation time of the reading signal of the CCD sensor that reads the display on the reading target provided corresponding to the predetermined phase relationship, and thereby This is done by matching the valid data signal and the valid read data.

Preferably, the timing signal having the predetermined phase relationship is a timing signal (center signal) that turns on when half of the time that the valid data signal is on has elapsed after the valid data signal turns on. Then, the display on the reading target 9 provided corresponding to the predetermined phase relationship is
This is a black line provided in the center of the object to be read.

(Operation) The operation will be explained by taking as an example the case where the above-mentioned center signal is used as the timing signal.

A black line provided at the center of the object to be read is read by a CCD sensor to obtain read data. In this state, the generation time of the center signal is adjusted so that it coincides with the position on the time axis of the read signal related to this black line. This adjustment may be performed, for example, while visually observing the above two signals with a synchroscope. If the generation time of the center signal matches the above read signal, the generation time of the valid data signal changes in accordance with the center signal, and eventually the generation time of the valid data signal coincides with the start end of the effective reading range of the object to be read. matches. That is, the range of the valid data signal and the valid read data match.

(Example) An example of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, a timing generator 6 generates a shift signal to be applied to the CCD sensor 4, and a valid data signal and a center signal whose phase can be arbitrarily set with respect to this shift signal. The center signal is a signal that always rises at the center of the section where the valid data signal is on. Furthermore, the phase of the valid data signal follows the phase of the center signal. The dip switch 8 is used to set the rising phase of the center signal with respect to the shift signal. The ditub switch 8 can adjust the rising phase of the center signal by several bits. The set value of the dip switch 8 is sent to the central processing unit 5 via the parallel in/out port 7. The central processing unit 5 controls the timing generator 6 according to this set value to determine the rising phase of the center signal relative to the shift signal. As mentioned above, the rising phase of the valid data signal with respect to the shift signal follows the phase of the center signal, so if the rising phase of the center signal υ is determined, the phase of the valid data signal is also determined. . The shift signal is supplied to the CCD sensor 4, the center signal to the synchroscope 10, and the valid data signal to a signal processing circuit (not shown). The output signal of the CCD sensor 4 is output to a signal processing circuit (not shown) via an amplifier, and is also supplied to a synchroscope 10.

Next, using the device having the configuration shown in FIG.
Figures 2 and 3 show how to adjust the effective reading range of
This will be explained with reference to the figures.

Fig. 2(a) shows that when the reading data of the CCD sensor 4 is moved to the left, the mounting position of the CCD sensor 4 is relative to the effective reading range as shown in Fig. 2(b). The timing of each signal is shown when it is as close to the upper side as possible. In this case, the read υ data ←) of the CCD sensor 4 is obtained as shown for the bit string (A) of the CCD sensor.

In this case, adjustment of the reading effective range is performed as follows. First, black data is added to the center of the original to be read, that is, the center of the effective reading range, and the other part of the original to be read is white. At this time, shift signal (c)
As the read data (A) read out from the CCD sensor 4 in response to the above, only the illustrated read data signal exists. In this case, the timing generator 6 generates a valid data signal (this is called an effective data signal before correction) and a center signal (this is called a center signal before correction) as shown in (a) and (g), respectively, for the shift signal (c). )
is outputting. As shown, read data (b)
is not located within the range of the valid data signal). The operator visually checks the center signal (G) displayed on the synchroscope 10 and the read data signal from the amplifier 9, and makes sure that the center signal (G) matches the read data signal (from the shift signal). a//2 bit length). This dip switch 8
The setting value is supplied to the central processing unit 5 via the parallel in/out port 7, and the central processing unit 5 controls the timing generator 6 to change the phase of the center signal. The center signal adjusted in this way (this is referred to as the corrected center signal) is shown in (f). Accordingly, the valid data signal before correction changes as shown in (e) (this is referred to as the valid data signal after correction). The corrected valid data signal (E) is turned on by the rising pa bit in synchronization with the shift signal (C). As a result, the read data signal is centered on the corrected valid data signal. In other words, the read data (b) will match the valid data signal (b). Therefore, all of the read data (b) in the range shown in the figure is taken in to a signal processing circuit (not shown) via the amplifier 9.

Figure 3 (a) shows when the read data (b) of the CCD sensor 4 is far to the right, that is, as shown in Figure 3 (b), the mounting position of the CCD sensor 4 is at the maximum position relative to the effective reading range. The timing of each signal when approaching the limit side is shown. In this case, the valid data signal) is shifted to the shift signal (c).
As shown in (e), the center signal (g) is turned on with a bit length of (l-a) (valid data signal after modification in (e) in the figure), and the center signal (g) is turned on as shown in (e) (shift signal (c) to ()). l-a/
2) Adjust so that it is turned on depending on the bit length.

Incidentally, in the above embodiment, the center signal does not necessarily have to be located at a/2 with respect to the valid data signal, for example, at 2a.
/3 may be used. In this case, a black line mark to be attached to the read document may also be attached in accordance with this.

(Effects of the Invention) As explained above, according to the present invention, the time of the valid data signal that determines the valid range of the output signal from the CCD sensor according to the position on the time axis of the nine reading ranges of the CCD sensor. Since the position on the axis is adjusted, it can be easily adjusted electrically without the need for complicated mechanical operations as in the past. Therefore, the effective reading range can be adjusted with high accuracy in a very short time.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a diagram showing a configuration for implementing the present invention, and FIGS. 2 and 3 are timing diagrams of the configuration of FIG. 1 when adjustment operations according to the present invention are performed, respectively. , FIG. 4 is a diagram schematically showing the optical system of a facsimile machine, and FIG. 5 is a timing diagram for explaining the conventional method. 4... CCD sensor, 5... Central processing unit, 6...
Timing generator, 7...Parallel in/out port, 8...Dip switch, 9...Amplifier, 1
0... Synchronoscope.

Claims (2)

[Claims] (1) Optically scan the reading target with a CCD sensor,
A method of adjusting so that a valid data signal that determines a range of valid data among output signals of a CD sensor matches valid read data of a CCD sensor related to a valid read range of a reading target, comprising: The generation time is made to follow the change in the generation time of a timing signal that always has a predetermined phase relationship with respect to the valid data signal, and the adjustment is made by reading an indication on the reading target provided corresponding to the predetermined phase relationship. An adjustment method comprising: adjusting the generation time of a timing signal so as to coincide with the generation time of a read signal of a CCD sensor, thereby making the valid data signal and the valid read data coincide. (2) The timing signal having the predetermined phase relationship is a timing signal that turns on when half of the time during which the valid data signal is on has elapsed after the valid data signal turns on; 2. The adjustment method according to claim 1, wherein the display provided on the reading object corresponding to the predetermined phase relationship is a black line provided at the center of the reading object.